203 results on '"Climate and Earth system modelling"'
Search Results
2. Is the detection of accelerated sea level rise imminent?
- Author
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Hamlington, B. [Old Dominion Univ., Norfolk, VA (United States)]
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- 2016
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3. The footprint of the inter-decadal Pacific oscillation in Indian Ocean sea surface temperatures
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Chen, Xiaolong [Chinese Academy of Sciences (CAS), Beijing (China); Univ. of Chinese Academy of Sciences, Beijing (China)]
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- 2016
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4. Future warming patterns linked to today’s climate variability
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Dai, Aiguo [Univ. at Albany, SUNY, Albany, NY (United States)]
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- 2016
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5. Muted extratropical low cloud seasonal cycle is closely linked to underestimated climate sensitivity in models
- Abstract
A large spread in model estimates of the equilibrium climate sensitivity (ECS), defined as the global mean near-surface air-temperature increase following a doubling of atmospheric CO2 concentration, leaves us greatly disadvantaged in guiding policy-making for climate change adaptation and mitigation. In this study, we show that the projected ECS in the latest generation of climate models is highly related to seasonal variations of extratropical low-cloud fraction (LCF) in historical simulations. Marked reduction of extratropical LCF from winter to summer is found in models with ECS > 4.75 K, in accordance with the significant reduction of extratropical LCF under a warming climate in these models. In contrast, a pronounced seasonal cycle of extratropical LCF, as supported by satellite observations, is largely absent in models with ECS < 3.3 K. The distinct seasonality in extratropical LCF in climate models is ascribed to their different prevailing cloud regimes governing the extratropical LCF variability.
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- 2023
6. Challenges with interpreting the impact of Atlantic Multidecadal Variability using SST-restoring experiments
- Abstract
Climate model simulations that restore SSTs in the North Atlantic have been used to explore the climate impacts of Atlantic Multidecadal Variability (AMV). However, despite simulations and observations exhibiting similar North Atlantic SST anomalies, experiments with active SST-restoring in the Tropical North Atlantic exhibit strong positive surface heat-fluxes out of the ocean with warm SST anomalies, which is not replicated in other simulations or observations. The upward surface heat-fluxes that are systematically driven by the active SST-restoring in the Tropical North Atlantic are found to be crucial for generating a strong local precipitation response and the associated remote impact on the Pacific Walker circulation; these are both absent in other simulations. The results of this study strongly suggest that experiments employing SST-restoring (or prescribed SSTs) in the Tropical North Atlantic exaggerate the influence of the Atlantic on patterns of global climate anomalies and its role in recent multidecadal SST trends., COR was supported by a Royal Society University Research Fellowship. MP was funded by the EUCP project (Horizon 2020; Grant Agreement 776613). JR was funded by NERC via the ACSIS program (NE/N018001/1) and via the WISHBONE project (NE/T013516/1). PAM was funded by the EMERGENCE project under the Natural Environment Research Council (NERC Grant NE/S004890/1) The project that gave rise to these results included YRR and received the support of a fellowship from “la Caixa” Foundation (ID 100010434) and from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No 847648 (fellowship code LCF/BQ/PR21/11840016)., Peer Reviewed, Postprint (published version)
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- 2023
7. Rapid 20th century warming reverses 900-year cooling in the Gulf of Maine
- Abstract
© The Author(s), 2022. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Whitney, N. M., Wanamaker, A. D., Ummenhofer, C. C., Johnson, B. J., Cresswell-Clay, N., & Kreutz, K. J. Rapid 20th century warming reverses 900-year cooling in the Gulf of Maine. Communications Earth & Environment, 3(1), (2022): 179, https://doi.org/10.1038/s43247-022-00504-8., The Gulf of Maine, located in the western North Atlantic, has undergone recent, rapid ocean warming but the lack of long-term, instrumental records hampers the ability to put these significant hydrographic changes into context. Here we present multiple 300-year long geochemical records (oxygen, nitrogen, and previously published radiocarbon isotopes) measured in absolutely-dated Arctica islandica shells from the western Gulf of Maine. These records, in combination with climate model simulations, suggest that the Gulf of Maine underwent a long-term cooling over most of the last 1000 years, driven primarily by volcanic forcing and North Atlantic ocean dynamics. This cooling trend was reversed by warming beginning in the late 1800s, likely due to increased atmospheric greenhouse gas concentrations and changes in western North Atlantic circulation. The climate model simulations suggest that the warming over the last century was more rapid than almost any other 100-year period in the last 1000 years in the region., Funding for this research was provided by the following sources: Bruce Bowen Fellowship (N.M.W.), Geological Society of America Graduate Student Research Grant (N.M.W.), James E. and Barbara V. Moltz Fellowship for Climate-Related Research at WHOI (C.C.U.), Maine Marine Research Fund (B.J.J.), National Oceanic and Atmospheric Administration Climate and Global Change Postdoctoral Fellowship (N.M.W.), National Science Foundation grant OCE 1003438 and MGG 2028197 (A.D.W.), National Science Foundation grant OCE 1003423 (K.J.K.), National Science Foundation grant OCE 0929900 (B.J.J.). We thank the CESM1(CAM5) Last Millennium Ensemble Community Project for providing the climate model simulations, which were performed using the supercomputing resources provided by NSF/CISL/Yellowstone.
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- 2023
8. Rapid 20th century warming reverses 900-year cooling in the Gulf of Maine
- Abstract
© The Author(s), 2022. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Whitney, N. M., Wanamaker, A. D., Ummenhofer, C. C., Johnson, B. J., Cresswell-Clay, N., & Kreutz, K. J. Rapid 20th century warming reverses 900-year cooling in the Gulf of Maine. Communications Earth & Environment, 3(1), (2022): 179, https://doi.org/10.1038/s43247-022-00504-8., The Gulf of Maine, located in the western North Atlantic, has undergone recent, rapid ocean warming but the lack of long-term, instrumental records hampers the ability to put these significant hydrographic changes into context. Here we present multiple 300-year long geochemical records (oxygen, nitrogen, and previously published radiocarbon isotopes) measured in absolutely-dated Arctica islandica shells from the western Gulf of Maine. These records, in combination with climate model simulations, suggest that the Gulf of Maine underwent a long-term cooling over most of the last 1000 years, driven primarily by volcanic forcing and North Atlantic ocean dynamics. This cooling trend was reversed by warming beginning in the late 1800s, likely due to increased atmospheric greenhouse gas concentrations and changes in western North Atlantic circulation. The climate model simulations suggest that the warming over the last century was more rapid than almost any other 100-year period in the last 1000 years in the region., Funding for this research was provided by the following sources: Bruce Bowen Fellowship (N.M.W.), Geological Society of America Graduate Student Research Grant (N.M.W.), James E. and Barbara V. Moltz Fellowship for Climate-Related Research at WHOI (C.C.U.), Maine Marine Research Fund (B.J.J.), National Oceanic and Atmospheric Administration Climate and Global Change Postdoctoral Fellowship (N.M.W.), National Science Foundation grant OCE 1003438 and MGG 2028197 (A.D.W.), National Science Foundation grant OCE 1003423 (K.J.K.), National Science Foundation grant OCE 0929900 (B.J.J.). We thank the CESM1(CAM5) Last Millennium Ensemble Community Project for providing the climate model simulations, which were performed using the supercomputing resources provided by NSF/CISL/Yellowstone.
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- 2023
9. Increasing extreme precipitation variability plays a key role in future record-shattering event probability.
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de Vries I, Sippel S, Zeder J, Fischer E, and Knutti R
- Abstract
Climate events that break records by large margins are a threat to society and ecosystems. Climate change is expected to increase the probability of such events, but quantifying these probabilities is challenging due to natural variability and limited data availability, especially for observations and very rare extremes. Here we estimate the probability of precipitation events that shatter records by a margin of at least one pre-industrial standard deviation. Using large ensemble climate simulations and extreme value theory, we determine empirical and analytical record shattering probabilities and find they are in high agreement. We show that, particularly in high emission scenarios, models project much higher record-shattering precipitation probabilities in a changing relative to a stationary climate by the end of the century for almost all the global land, with the strongest increases in vulnerable regions in the tropics. We demonstrate that increasing variability is an essential driver of near-term increases in record-shattering precipitation probability, and present a framework that quantifies the influence of combined trends in mean and variability on record-shattering behaviour in extreme precipitation. Probability estimates of record-shattering precipitation events in a warming world are crucial to inform risk assessment and adaptation policies., Competing Interests: Competing interestsThe authors declare no competing interests., (© The Author(s) 2024.)
- Published
- 2024
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10. Abrupt reduction in shipping emission as an inadvertent geoengineering termination shock produces substantial radiative warming.
- Author
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Yuan T, Song H, Oreopoulos L, Wood R, Bian H, Breen K, Chin M, Yu H, Barahona D, Meyer K, and Platnick S
- Abstract
Human activities affect the Earth's climate through modifying the composition of the atmosphere, which then creates radiative forcing that drives climate change. The warming effect of anthropogenic greenhouse gases has been partially balanced by the cooling effect of anthropogenic aerosols. In 2020, fuel regulations abruptly reduced the emission of sulfur dioxide from international shipping by about 80% and created an inadvertent geoengineering termination shock with global impact. Here we estimate the regulation leads to a radiative forcing of + 0.2 ± 0.11 Wm
-2 averaged over the global ocean. The amount of radiative forcing could lead to a doubling (or more) of the warming rate in the 2020 s compared with the rate since 1980 with strong spatiotemporal heterogeneity. The warming effect is consistent with the recent observed strong warming in 2023 and expected to make the 2020 s anomalously warm. The forcing is equivalent in magnitude to 80% of the measured increase in planetary heat uptake since 2020. The radiative forcing also has strong hemispheric contrast, which has important implications for precipitation pattern changes. Our result suggests marine cloud brightening may be a viable geoengineering method in temporarily cooling the climate that has its unique challenges due to inherent spatiotemporal heterogeneity., Competing Interests: Competing interestsThe authors declare no competing interests., (© The Author(s) 2024.)- Published
- 2024
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11. Large-scale dynamics moderate impact-relevant changes to organised convective storms
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Steven C. Chan, Elizabeth J. Kendon, Hayley J. Fowler, Abdullah Kahraman, Julia Crook, Nikolina Ban, and Andreas F. Prein
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Atmospheric science ,Climate change ,General Earth and Planetary Sciences ,Climate and Earth system modelling ,General Environmental Science - Abstract
Larger organised convective storms (mesoscale-convective systems) can lead to major flood events in Europe. Here we assess end-of-century changes to their characteristics in two convection-permitting climate simulations from the UK Met Office and ETH-Zürich that both use the high Representative Concentration Pathway 8.5 scenario but different approaches to represent atmospheric changes with global warming and different models. The UK Met Office projections indicate more frequent, smaller, and slower-moving storms, while ETH-Zürich projections show fewer, larger, and faster-moving storms. However, both simulations show increases to peak precipitation intensity, total precipitation volume, and temporal clustering, suggesting increasing risks from mesoscale-convective systems in the future. Importantly, the largest storms that pose increased flood risks are projected to increase in frequency and intensity. These results highlight that understanding large-scale dynamical drivers as well as the thermodynamical response of storms is essential for accurate projections of changes to storm hazards, needed for future climate adaptation., Communications Earth & Environment, 4 (1), ISSN:2662-4435
- Published
- 2023
12. Early detection of anthropogenic climate change signals in the ocean interior
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Jerry F. Tjiputra, Jean Negrel, and Are Olsen
- Subjects
Multidisciplinary ,Carbon cycle ,Climate and Earth system modelling - Abstract
Robust detection of anthropogenic climate change is crucial to: (i) improve our understanding of Earth system responses to external forcing, (ii) reduce uncertainty in future climate projections, and (iii) develop efficient mitigation and adaptation plans. Here, we use Earth system model projections to establish the detection timescales of anthropogenic signals in the global ocean through analyzing temperature, salinity, oxygen, and pH evolution from surface to 2000 m depths. For most variables, anthropogenic changes emerge earlier in the interior ocean than at the surface, due to the lower background variability at depth. Acidification is detectable earliest, followed by warming and oxygen changes in the subsurface tropical Atlantic. Temperature and salinity changes in the subsurface tropical and subtropical North Atlantic are shown to be early indicators for a slowdown of the Atlantic Meridional Overturning Circulation. Even under mitigated scenarios, inner ocean anthropogenic signals are projected to emerge within the next few decades. This is because they originate from existing surface changes that are now propagating into the interior. In addition to the tropical Atlantic, our study calls for establishment of long-term interior monitoring systems in the Southern Ocean and North Atlantic in order to elucidate how spatially heterogeneous anthropogenic signals propagate into the interior and impact marine ecosystems and biogeochemistry.
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- 2023
13. Vegetation-based climate mitigation in a warmer and greener World
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Ramdane Alkama, Giovanni Forzieri, Gregory Duveiller, Giacomo Grassi, Shunlin Liang, and Alessandro Cescatti
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Carbon Sequestration ,Multidisciplinary ,Atmosphere ,Earth, Planet ,Climate ,Climate Change ,Science ,Temperature ,General Physics and Astronomy ,Climate-change policy ,General Chemistry ,Carbon cycle ,Models, Theoretical ,Global Warming ,General Biochemistry, Genetics and Molecular Biology ,Article ,Projection and prediction ,Climate and Earth system modelling ,Climate-change mitigation - Abstract
The mitigation potential of vegetation-driven biophysical effects is strongly influenced by the background climate and will therefore be influenced by global warming. Based on an ensemble of remote sensing datasets, here we first estimate the temperature sensitivities to changes in leaf area over the period 2003–2014 as a function of key environmental drivers. These sensitivities are then used to predict temperature changes induced by future leaf area dynamics under four scenarios. Results show that by 2100, under high-emission scenario, greening will likely mitigate land warming by 0.71 ± 0.40 °C, and 83% of such effect (0.59 ± 0.41 °C) is driven by the increase in plant carbon sequestration, while the remaining cooling (0.12 ± 0.05 °C) is due to biophysical land-atmosphere interactions. In addition, our results show a large potential of vegetation to reduce future land warming in the very-stringent scenario (35 ± 20% of the overall warming signal), whereas this effect is limited to 11 ± 6% under the high-emission scenario., Vegetation changes have been suggested as a climate mitigation option, but the numerous feedbacks between vegetation and climate are not well understood. Here, the authors show that greening leads to surface cooling in many areas, but the size of the effect depends on the background climate.
- Published
- 2022
14. Diagnosing challenges and setting priorities for sustainable water resource management under climate change
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Ibrahim Nourein, Mohammed, John D, Bolten, Nicholas J, Souter, Kashif, Shaad, and Derek, Vollmer
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Multidisciplinary ,Science ,Climate-change policy ,Article ,Projection and prediction ,Environmental impact ,Climate-change adaptation ,Sustainability ,Medicine ,Hydrology ,Climate-change impacts ,Climate and Earth system modelling - Abstract
Managing transboundary river basins requires balancing tradeoffs of sustainable water use and coping with climate uncertainty. We demonstrate an integrated approach to exploring these issues through the lens of a social-ecological system, combining remote and in-situ earth observations, hydrologic and climate models, and social surveys. Specifically, we examine how climate change and dam development could impact the Se Kong, Se San and Sre Pok rivers in the Mekong region. We find that climate change will lead to increased precipitation, necessitating a shift in dam operations, from maintaining low flows to reducing flood hazards. We also find that existing water governance systems in Laos, Vietnam, and Cambodia are ill-prepared to address the problem. We conclude that the solution space for addressing these complex issues will be highly constrained unless major deficiencies in transboundary water governance, strategic planning, financial capacity, information sharing, and law enforcement are remedied in the next decades.
- Published
- 2022
15. Indicate separate contributions of long-lived and short-lived greenhouse gases in emission targets
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Myles R. Allen, Glen P. Peters, Keith P. Shine, Christian Azar, Paul Balcombe, Olivier Boucher, Michelle Cain, Philippe Ciais, William Collins, Piers M. Forster, Dave J. Frame, Pierre Friedlingstein, Claire Fyson, Thomas Gasser, Bill Hare, Stuart Jenkins, Steven P. Hamburg, Daniel J. A. Johansson, John Lynch, Adrian Macey, Johannes Morfeldt, Alexander Nauels, Ilissa Ocko, Michael Oppenheimer, Stephen W. Pacala, Raymond Pierrehumbert, Joeri Rogelj, Michiel Schaeffer, Carl F. Schleussner, Drew Shindell, Ragnhild B. Skeie, Stephen M. Smith, Katsumasa Tanaka, Environmental Sciences, and Integr. Assessm. Global Environm. Change
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Global and Planetary Change ,Atmospheric Science ,010504 meteorology & atmospheric sciences ,010501 environmental sciences ,01 natural sciences ,Environmental sciences ,Meteorology. Climatology ,Environmental Chemistry ,Business ,GE1-350 ,QC851-999 ,Climate and Earth system modelling ,Climate-change mitigation ,0105 earth and related environmental sciences - Abstract
European Union funding: 821205, 821003, 820829. Wellcome Trust: 205212/Z/16/Z
- Published
- 2022
16. New climate models reveal faster and larger increases in Arctic precipitation than previously projected
- Author
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Julienne Stroeve, Mark C. Serreze, James A. Screen, Michelle R. McCrystall, and Bruce C. Forbes
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Coupled model intercomparison project ,Multidisciplinary ,Science ,Global warming ,General Physics and Astronomy ,General Chemistry ,Snow ,General Biochemistry, Genetics and Molecular Biology ,Article ,Projection and prediction ,Arctic ,Climatology ,Polar amplification ,Environmental science ,Climate model ,Precipitation ,Water cycle ,Climate and Earth system modelling - Abstract
As the Arctic continues to warm faster than the rest of the planet, evidence mounts that the region is experiencing unprecedented environmental change. The hydrological cycle is projected to intensify throughout the twenty-first century, with increased evaporation from expanding open water areas and more precipitation. The latest projections from the sixth phase of the Coupled Model Intercomparison Project (CMIP6) point to more rapid Arctic warming and sea-ice loss by the year 2100 than in previous projections, and consequently, larger and faster changes in the hydrological cycle. Arctic precipitation (rainfall) increases more rapidly in CMIP6 than in CMIP5 due to greater global warming and poleward moisture transport, greater Arctic amplification and sea-ice loss and increased sensitivity of precipitation to Arctic warming. The transition from a snow- to rain-dominated Arctic in the summer and autumn is projected to occur decades earlier and at a lower level of global warming, potentially under 1.5 °C, with profound climatic, ecosystem and socio-economic impacts., The Arctic warms faster than other areas of the planet, which also influences precipitation. Here, the authors show that the latest CMIP6 model ensemble shows a faster Arctic warming and sea-ice loss, causing an earlier transition from a snow- to a rain-dominated Arctic than previously thought.
- Published
- 2021
17. Assessing the impact of suppressing Southern Ocean SST variability in a coupled climate model
- Author
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Giovanni Liguori, Ghyslaine Boschat, Ariaan Purich, Purich, Ariaan, Boschat, Ghyslaine, and Liguori, Giovanni
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SST variability ,geography ,Atmospheric dynamics ,Multidisciplinary ,geography.geographical_feature_category ,Mixed layer ,Physical oceanography ,Science ,Ocean current ,Lead (sea ice) ,Publisher Correction ,Article ,Latitude ,Climatology ,Middle latitudes ,Sea ice ,Environmental science ,Medicine ,Climate model ,Southern Ocean ,Southern Hemisphere ,Climate and Earth system modelling ,Coupled Climate Model - Abstract
The Southern Ocean exerts a strong influence on global climate, regulating the storage and transport of heat, freshwater and carbon throughout the world’s oceans. While the majority of previous studies focus on how wind changes influence Southern Ocean circulation patterns, here we set out to explore potential feedbacks from the ocean to the atmosphere. To isolate the role of oceanic variability on Southern Hemisphere climate, we perform coupled climate model experiments in which Southern Ocean variability is suppressed by restoring sea surface temperatures (SST) over 40°–65°S to the model’s monthly mean climatology. We find that suppressing Southern Ocean SST variability does not impact the Southern Annular Mode, suggesting air–sea feedbacks do not play an important role in the persistence of the Southern Annular Mode in our model. Suppressing Southern Ocean SST variability does lead to robust mean-state changes in SST and sea ice. Changes in mixed layer processes and convection associated with the SST restoring lead to SST warming and a sea ice decline in southern high latitudes, and SST cooling in midlatitudes. These results highlight the impact non-linear processes can have on a model’s mean state, and the need to consider these when performing simulations of the Southern Ocean.
- Published
- 2021
18. Ambitious partnership needed for reliable climate prediction
- Abstract
Current global climate models struggle to represent precipitation and related extreme events, with serious implications for the physical evidence base to support climate actions. A leap to kilometre-scale models could overcome this shortcoming but requires collaboration on an unprecedented scale.
- Published
- 2022
19. Robust but weak winter atmospheric circulation response to future Arctic sea ice loss
- Abstract
The possibility that Arctic sea ice loss weakens mid-latitude westerlies, promoting more severe cold winters, has sparked more than a decade of scientific debate, with apparent support from observations but inconclusive modelling evidence. Here we show that sixteen models contributing to the Polar Amplification Model Intercomparison Project simulate a weakening of mid-latitude westerlies in response to projected Arctic sea ice loss. We develop an emergent constraint based on eddy feedback, which is 1.2 to 3 times too weak in the models, suggesting that the real-world weakening lies towards the higher end of the model simulations. Still, the modelled response to Arctic sea ice loss is weak: the North Atlantic Oscillation response is similar in magnitude and offsets the projected response to increased greenhouse gases, but would only account for around 10% of variations in individual years. We further find that relationships between Arctic sea ice and atmospheric circulation have weakened recently in observations and are no longer inconsistent with those in models., D.M.S., R.E., L.H., L.S.G., T.J., T.S., X.L., and P.O. were supported by the EU H2020 APPLICATE project (GA727862). The Met Office contribution was also supported by the Met Office Hadley Centre Climate Programme funded by BEIS and Defra and by the UK-China Research and Innovation Partnership Fund through the Met Office Climate Science for Service Partnership (CSSP) China as part of the Newton Fund. J.A.S was supported by NERC grants NE/P006760/1, NE/R005125/1 and NE/V005855/1. G.M and Y.P. were supported by the US Department of Energy, grant number DE-SC0019407. L.S.G was also supported by the Research council of Norway INES project (270061), and the Norwegian e-infrastructure for Research and Education (UNINETT Sigma2) through projects NN2345K, NS2345K and NS9034K. E.M. and D.M. acknowledge the support of the German Federal Ministry of Education and Research through the JPI Climate/JPI Oceans NextG-Climate Science-ROADMAP (FKZ: 01LP2002A) project and of the European Union’s Horizon 2020 Programme through the Blue-Action Project (GA727852); and the use of resources from the DKRZ bm0966 and bm1190 projects. C. Deser acknowledges support from the National Center for Atmospheric Research, which is a major facility sponsored by the US National Science Foundation under cooperative agreement 1852977. M.M. was supported by MEXT through the Integrated Research Program for Advancing Climate Models (JPMXD0717935457) and ArCS II (JPMXD1420318865) programs, and by the Environment Research and Technology Development Fund (JPMEERF20192004). J.G.-S. and P.O. were supported by the Spanish Ramón y Cajal’ programme (RYC-2016-21181, RYC-2016-22772). B.H. was jointly funded by the Strategic Priority Research Program of the Chinese Academy of Sciences (Grant No. XDA19070404) and the National Natural Science Foundation of China (Grant Nos. 42030602, 91837101). G.G. was supported by the EU H2020 Blue–Action (GA727852) project and uses the HPC resources of TGCC under the allocations 2018, Peer Reviewed, "Article signat per 31 autors/es: D. M. Smith, R. Eade, M. B. Andrews, H. Ayres, A. Clark, S. Chripko, C. Deser, N. J. Dunstone, J. García-Serrano, G. Gastineau, L. S. Graff, S. C. Hardiman, B. He, L. Hermanson, T. Jung, J. Knight, X. Levine, G. Magnusdottir, E. Manzini, D. Matei, M. Mori, R. Msadek, P. Ortega, Y. Peings, A. A. Scaife, J. A. Screen, M. Seabrook, T. Semmler, M. Sigmond, J. Streffing, L. Sun & A. Walsh ", Postprint (published version)
- Published
- 2022
20. Increasing probability of record-shattering climate extremes
- Author
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Erich M. Fischer, Sebastian Sippel, and Reto Knutti
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010504 meteorology & atmospheric sciences ,Global warming ,0207 environmental engineering ,02 engineering and technology ,Environmental Science (miscellaneous) ,01 natural sciences ,Observational period ,Extreme heat ,13. Climate action ,Climate and Earth system modelling ,Projection and prediction ,Middle latitudes ,Climatology ,Environmental science ,020701 environmental engineering ,Climate extremes ,Social Sciences (miscellaneous) ,Warming rate ,0105 earth and related environmental sciences - Abstract
Recent climate extremes have broken long-standing records by large margins. Such extremes unprecedented in the observational period often have substantial impacts due to a tendency to adapt to the highest intensities, and no higher, experienced during a lifetime. Here, we show models project not only more intense extremes but also events that break previous records by much larger margins. These record-shattering extremes, nearly impossible in the absence of warming, are likely to occur in the coming decades. We demonstrate that their probability of occurrence depends on warming rate, rather than global warming level, and is thus pathway-dependent. In high-emission scenarios, week-long heat extremes that break records by three or more standard deviations are two to seven times more probable in 2021–2050 and three to 21 times more probable in 2051–2080, compared to the last three decades. In 2051–2080, such events are estimated to occur about every 6–37 years somewhere in the northern midlatitudes. Changes in extreme heat are often calculated as anomalies above a reference climatology. A different definition—week-day heatwaves surpassing the current record by large margins—shows that their occurrence probabilities depend on warming rate, not level, and are higher than during recent decades.
- Published
- 2021
21. Anthropogenic influence on extreme precipitation over global land areas seen in multiple observational datasets
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Gavin D. Madakumbura, Naomi Goldenson, Alex Hall, Chad W. Thackeray, and Jesse Norris
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010504 meteorology & atmospheric sciences ,Science ,General Physics and Astronomy ,Climate change ,Forcing (mathematics) ,01 natural sciences ,General Biochemistry, Genetics and Molecular Biology ,Article ,Projection and prediction ,03 medical and health sciences ,Attribution ,Precipitation ,Climate and Earth system modelling ,030304 developmental biology ,0105 earth and related environmental sciences ,0303 health sciences ,Multidisciplinary ,General Chemistry ,Internal variability ,General Circulation Model ,Climatology ,Spatial ecology ,Environmental science ,Climate model ,Observational study - Abstract
The intensification of extreme precipitation under anthropogenic forcing is robustly projected by global climate models, but highly challenging to detect in the observational record. Large internal variability distorts this anthropogenic signal. Models produce diverse magnitudes of precipitation response to anthropogenic forcing, largely due to differing schemes for parameterizing subgrid-scale processes. Meanwhile, multiple global observational datasets of daily precipitation exist, developed using varying techniques and inhomogeneously sampled data in space and time. Previous attempts to detect human influence on extreme precipitation have not incorporated model uncertainty, and have been limited to specific regions and observational datasets. Using machine learning methods that can account for these uncertainties and capable of identifying the time evolution of the spatial patterns, we find a physically interpretable anthropogenic signal that is detectable in all global observational datasets. Machine learning efficiently generates multiple lines of evidence supporting detection of an anthropogenic signal in global extreme precipitation., Climate models project an intensification of extreme precipitation under climate change, but this effect is difficult to detect in the observational record. Here, the authors show that a physically interpretable anthropogenic impact on extreme precipitation is detectable in global observational data sets.
- Published
- 2021
22. Climate mitigation from vegetation biophysical feedbacks during the past three decades
- Author
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Wang, Yingping [Commonwealth Scientific and Industrial Research Organization (CSIRO), Aspendale, VIC (Australia)]
- Published
- 2017
- Full Text
- View/download PDF
23. Cyclonic and anticyclonic contributions to atmospheric energetics
- Author
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Satoru Okajima, Yohai Kaspi, and Hisashi Nakamura
- Subjects
Jet (fluid) ,Atmospheric dynamics ,Multidisciplinary ,010504 meteorology & atmospheric sciences ,Physical oceanography ,Baroclinity ,Science ,Westerlies ,Jet stream ,010502 geochemistry & geophysics ,01 natural sciences ,Article ,Eddy ,Anticyclone ,Middle latitudes ,Climatology ,Medicine ,Storm track ,Climate and Earth system modelling ,Geology ,0105 earth and related environmental sciences - Abstract
Migratory cyclones and anticyclones account for most of the day-to-day weather variability in the extratropics. These transient eddies act to maintain the midlatitude jet streams by systematically transporting westerly momentum and heat. Yet, little is known about the separate contributions of cyclones and anticyclones to their interaction with the westerlies. Here, using a novel methodology for identifying cyclonic and anticyclonic vortices based on curvature, we quantify their separate contributions to atmospheric energetics and their feedback on the westerly jet streams as represented in Eulerian statistics. We show that climatological westerly acceleration by cyclonic vortices acts to dominantly reinforce the wintertime eddy-driven near-surface westerlies and associated cyclonic shear. Though less baroclinic and energetic, anticyclones still play an important role in transporting westerly momentum toward midlatitudes from the upper-tropospheric thermally driven jet core and carrying eddy energy downstream. These new findings have uncovered essential characteristics of atmospheric energetics, storm track dynamics and eddy-mean flow interaction.
- Published
- 2021
24. Deep learning for bias correction of MJO prediction
- Author
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Y. S. Joo, Seok-Woo Son, Hye-Mi Kim, and Yoo-Geun Ham
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Systematic error ,010504 meteorology & atmospheric sciences ,Science ,General Physics and Astronomy ,Forecast skill ,010502 geochemistry & geophysics ,01 natural sciences ,Article ,General Biochemistry, Genetics and Molecular Biology ,Bias correction ,Predictability ,Climate and Earth system modelling ,0105 earth and related environmental sciences ,Atmospheric dynamics ,Multidisciplinary ,business.industry ,Deep learning ,Madden–Julian oscillation ,General Chemistry ,Numerical models ,Indian ocean ,Climatology ,Environmental science ,Artificial intelligence ,business - Abstract
Producing accurate weather prediction beyond two weeks is an urgent challenge due to its ever-increasing socioeconomic value. The Madden-Julian Oscillation (MJO), a planetary-scale tropical convective system, serves as a primary source of global subseasonal (i.e., targeting three to four weeks) predictability. During the past decades, operational forecasting systems have improved substantially, while the MJO prediction skill has not yet reached its potential predictability, partly due to the systematic errors caused by imperfect numerical models. Here, to improve the MJO prediction skill, we blend the state-of-the-art dynamical forecasts and observations with a Deep Learning bias correction method. With Deep Learning bias correction, multi-model forecast errors in MJO amplitude and phase averaged over four weeks are significantly reduced by about 90% and 77%, respectively. Most models show the greatest improvement for MJO events starting from the Indian Ocean and crossing the Maritime Continent., The Madden-Julian Oscillation (MJO) is a crucial component of the tropical weather system, but forecasting it has been challenging. Here, the authors present a deep learning bias correction method that significantly improves multi-model forecasts of the MJO amplitude and phase for up to four weeks.
- Published
- 2021
25. Challenges with interpreting the impact of Atlantic Multidecadal Variability using SST-restoring experiments
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Christopher H. O’Reilly, Matthew Patterson, Jon Robson, Paul Arthur Monerie, Daniel Hodson, Yohan Ruprich-Robert, and Barcelona Supercomputing Center
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Atmospheric dynamics ,Attribution ,Atmospheric Science ,Global and Planetary Change ,Enginyeria agroalimentària::Ciències de la terra i de la vida::Climatologia i meteorologia [Àrees temàtiques de la UPC] ,Physical oceanography ,Simulació per ordinador ,Environmental Chemistry ,Teleconnections (Climatology) ,Ocean-atmosphere interaction ,Climate and Earth system modelling ,Projection and prediction - Abstract
Climate model simulations that restore SSTs in the North Atlantic have been used to explore the climate impacts of Atlantic Multidecadal Variability (AMV). However, despite simulations and observations exhibiting similar North Atlantic SST anomalies, experiments with active SST-restoring in the Tropical North Atlantic exhibit strong positive surface heat-fluxes out of the ocean with warm SST anomalies, which is not replicated in other simulations or observations. The upward surface heat-fluxes that are systematically driven by the active SST-restoring in the Tropical North Atlantic are found to be crucial for generating a strong local precipitation response and the associated remote impact on the Pacific Walker circulation; these are both absent in other simulations. The results of this study strongly suggest that experiments employing SST-restoring (or prescribed SSTs) in the Tropical North Atlantic exaggerate the influence of the Atlantic on patterns of global climate anomalies and its role in recent multidecadal SST trends. COR was supported by a Royal Society University Research Fellowship. MP was funded by the EUCP project (Horizon 2020; Grant Agreement 776613). JR was funded by NERC via the ACSIS program (NE/N018001/1) and via the WISHBONE project (NE/T013516/1). PAM was funded by the EMERGENCE project under the Natural Environment Research Council (NERC Grant NE/S004890/1) The project that gave rise to these results included YRR and received the support of a fellowship from “la Caixa” Foundation (ID 100010434) and from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No 847648 (fellowship code LCF/BQ/PR21/11840016).
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- 2022
26. Global terrestrial water storage and drought severity under climate change
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Camelia Eliza Telteu, Jacob Schewe, Anne Gädeke, Tobias Stacke, Aristeidis Koutroulis, Hyungjun Kim, Lukas Gudmundsson, Dieter Gerten, Julien Boulange, Wim Thiery, Hannes Müller Schmied, Lamprini Papadimitriou, Naota Hanasaki, Yoshihide Wada, Farshid Felfelani, Fang Zhao, Peter Burek, Junguo Liu, Manolis Grillakis, Simon N. Gosling, Yusuke Satoh, Yadu Pokhrel, Ted Veldkamp, Water and Climate Risk, and Hydrology and Hydraulic Engineering
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010504 meteorology & atmospheric sciences ,Population ,Climate change ,Environmental Science (miscellaneous) ,01 natural sciences ,Projection and prediction ,03 medical and health sciences ,Hydrology (agriculture) ,SDG 13 - Climate Action ,Water cycle ,education ,Climate and Earth system modelling ,Southern Hemisphere ,Terrestrial water storage ,030304 developmental biology ,0105 earth and related environmental sciences ,0303 health sciences ,education.field_of_study ,15. Life on land ,Radiative forcing ,6. Clean water ,Climate change mitigation ,13. Climate action ,Environmental science ,Hydrology ,Water resource management ,SDG 6 - Clean Water and Sanitation ,Climate-change impacts ,Social Sciences (miscellaneous) - Abstract
Terrestrial water storage (TWS) modulates the hydrological cycle and is a key determinant of water availability and an indicator of drought. While historical TWS variations have been increasingly studied, future changes in TWS and the linkages to droughts remain unexamined. Here, using ensemble hydrological simulations, we show that climate change could reduce TWS in many regions, especially those in the Southern Hemisphere. Strong inter-ensemble agreement indicates high confidence in the projected changes that are driven primarily by climate forcing rather than land and water management activities. Declines in TWS translate to increases in future droughts. By the late twenty-first century, the global land area and population in extreme-to-exceptional TWS drought could more than double, each increasing from 3% during 1976–2005 to 7% and 8%, respectively. Our findings highlight the importance of climate change mitigation to avoid adverse TWS impacts and increased droughts, and the need for improved water resource management and adaptation., Terrestrial water storage (TWS) modulates the hydrological cycle and is a key determinant of water availability and an indicator of drought. While historical TWS variations have been increasingly studied, future changes in TWS and the linkages to droughts remain unexamined. Here, using ensemble hydrological simulations, we show that climate change could reduce TWS in many regions, especially those in the Southern Hemisphere. Strong inter-ensemble agreement indicates high confidence in the projected changes that are driven primarily by climate forcing rather than land and water management activities. Declines in TWS translate to increases in future droughts. By the late twenty-first century, the global land area and population in extreme-to-exceptional TWS drought could more than double, each increasing from 3% during 1976–2005 to 7% and 8%, respectively. Our findings highlight the importance of climate change mitigation to avoid adverse TWS impacts and increased droughts, and the need for improved water resource management and adaptation. © 2021, The Author(s), under exclusive licence to Springer Nature Limited.
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- 2021
27. Impact of climate change and management strategies on water and salt balance of the polders and islands in the Ganges delta
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John M. Kirby, Fazlul Karim, Donald S. Gaydon, and Mohammed Mainuddin
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Irrigation ,Multidisciplinary ,010504 meteorology & atmospheric sciences ,Science ,Water storage ,Climate change ,010501 environmental sciences ,01 natural sciences ,Article ,Salinity ,Hydrology (agriculture) ,Dry season ,Environmental science ,Medicine ,Hydrology ,Water resource management ,Surface runoff ,Climate and Earth system modelling ,Groundwater ,0105 earth and related environmental sciences - Abstract
Enhancing crop production, particularly by growing a crop in the typically-fallow dry season is a key strategy for alleviating poverty in the Ganges delta region. We used a polder water and salt balance model to examine the impact of several crop management, salt management and climate change scenarios on salinity and crop evapotranspiration at Dacope and Amtali in Bangladesh and Gosaba in India. A key (and unsurprising) finding is that salt management is very important, particularly at the two drier sites, Dacope and Gosaba. Good salt management lowers salinity in the shallow groundwater, soil and water storage ponds, and leads to more irrigation. Climate change is projected to alter rainfall, and this in turn leads to modelled increases or decreases in runoff from the polders, and thence affect salt concentrations in the soil and ponds and canals. Thus, the main impacts of climate change are through the indirect impacts on salt concentrations, rather than the direct impacts of the amount of water supplied as rainfall. Management practices to remove salt from polders are therefore likely to be effective in combatting the impacts of projected climate change particularly at Dacope and Gosaba.
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- 2021
28. Boundary condition and oceanic impacts on the atmospheric water balance in limited area climate model ensembles
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Goergen, Klaus and Kollet, Stefan
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Science ,Medicine ,Hydrology ,Climate and Earth system modelling ,ddc:600 ,Article ,Physics::Atmospheric and Oceanic Physics ,Physics::Geophysics - Abstract
Regional climate models (RCMs) are indispensable in climate research, albeit often characterized by biased terrestrial precipitation and water budgets. This study identifies excess oceanic evaporation, in conjunction with the RCMs’ boundary conditions, as drivers contributing to these biases in RCMs with forced sea surface temperatures in a CORDEX RCM ensemble over Europe. The RCMs are relaxed to the prescribed lateral boundary conditions originating from a global model, effectively matching the driving model's overall atmospheric moisture flux divergence. As a consequence, excess oceanic evaporation results in positive precipitation biases over land due to forced internal recycling of moisture to maintain the overall flux divergence prescribed by the boundary conditions. This systematic behaviour is shown through an analysis of long-term atmospheric water budgets and atmospheric moisture exchange between oceanic and continental areas in a multi-model ensemble.
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- 2021
29. Labrador Sea freshening linked to Beaufort Gyre freshwater release
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Wilbert Weijer, Tarun Verma, Michael Steele, Jiaxu Zhang, Milena Veneziani, and Wei Cheng
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geography ,Multidisciplinary ,geography.geographical_feature_category ,010504 meteorology & atmospheric sciences ,Beaufort Gyre ,Physical oceanography ,010505 oceanography ,Science ,Ocean current ,General Physics and Astronomy ,General Chemistry ,01 natural sciences ,Article ,General Biochemistry, Genetics and Molecular Biology ,Salinity ,Current (stream) ,Oceanography ,Arctic ,Archipelago ,Period (geology) ,Environmental science ,Meltwater ,Climate and Earth system modelling ,0105 earth and related environmental sciences - Abstract
The Beaufort Gyre (BG), the largest Arctic Ocean freshwater reservoir, has drastically increased its liquid freshwater content by 40% in the past two decades. If released within a short period, the excess freshwater could potentially impact the large-scale ocean circulation by freshening the upper subpolar North Atlantic. Here, we track BG-sourced freshwater using passive tracers in a global ocean sea-ice model and show that this freshwater exited the Arctic mostly through the Canadian Arctic Archipelago, rather than Fram Strait, during an historical release event in 1983–1995. The Labrador Sea is the most affected region in the subpolar North Atlantic, with a freshening of 0.2 psu on the western shelves and 0.4 psu in the Labrador Current. Given that the present BG freshwater content anomaly is twice the historical analog studied here, the impact of a future rapid release on Labrador Sea salinity could be significant, easily exceeding similar fluxes from Greenland meltwater., The Beaufort Gyre in the western Arctic Ocean has accumulated a large amount of freshwater. Here, the authors show that a historical release in the 1980s resulted in a strong freshening of the western Labrador Sea, suggesting that a future release of the current freshwater volume could even be more impactful.
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- 2021
30. Trans-basin Atlantic-Pacific connections further weakened by common model Pacific mean SST biases
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Dietmar Dommenget, Shayne McGregor, and Chen Li
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0301 basic medicine ,010504 meteorology & atmospheric sciences ,Science ,Surface warming ,General Physics and Astronomy ,Climate change ,Structural basin ,01 natural sciences ,Article ,General Biochemistry, Genetics and Molecular Biology ,03 medical and health sciences ,Atmospheric instability ,lcsh:Science ,Climate and Earth system modelling ,0105 earth and related environmental sciences ,Tropical pacific ,Atmospheric dynamics ,Multidisciplinary ,General Chemistry ,Sea surface temperature ,030104 developmental biology ,Climatology ,Environmental science ,Climate model ,lcsh:Q ,Teleconnection - Abstract
A robust eastern Pacific surface temperature cooling trend was evident between ~1990–2013 that was considered as a pronounced contributor to the global surface warming slowdown. The majority of current climate models failed to reproduce this Pacific cooling trend, which is at least partly due to the underrepresentation of trans-basin teleconnections. Here, we investigate whether common Pacific mean sea surface temperature biases may further diminish the Atlantic-Pacific trans-basin induced Pacific cooling. Our results suggest that background Pacific SST biases act to weaken the trans-basin teleconnection by strengthening the Atlantic atmospheric stability and reducing Atlantic convection. These Pacific SST biases also act to substantially undermine the positive zonal wind-SST feedback. Furthermore, when combined, the Pacific and Atlantic SST biases led to Pacific cooling response that is almost non-existent (underestimated by 89%). Future efforts aim at reducing the model mean state biases may significantly help to improve the simulation skills of trans-basin teleconnections., Many climate models failed to reproduce the eastern Pacific cooling that has been linked to slower warming in the early 20th century. Here, the authors present a feedback mechanism between the tropical Pacific and the Atlantic which contributes to this bias as it further dampens the Pacific cooling response in models.
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- 2020
31. High resolution spatiotemporal patterns of seawater temperatures across the Belize Mesoamerican Barrier Reef
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Randi D. Rotjan, Scott Jones, Karl D. Castillo, Brian Helmuth, Clare Fieseler, James J. Leichter, and Francis Choi
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0106 biological sciences ,Statistics and Probability ,Data Descriptor ,010504 meteorology & atmospheric sciences ,Coral bleaching ,Coral ,Library and Information Sciences ,01 natural sciences ,Projection and prediction ,Education ,Water column ,lcsh:Science ,Reef ,Climate and Earth system modelling ,0105 earth and related environmental sciences ,Ecological modelling ,Marine biology ,geography ,geography.geographical_feature_category ,Physical oceanography ,010604 marine biology & hydrobiology ,Coral reef ,Computer Science Applications ,Sea surface temperature ,Oceanography ,Benthic zone ,Environmental science ,Seawater ,lcsh:Q ,Statistics, Probability and Uncertainty ,Information Systems - Abstract
Coral reefs are under increasingly severe threat from climate change and other anthropogenic stressors. Anomalously high seawater temperatures in particular are known to cause coral bleaching (loss of algal symbionts in the family Symbiodiniaceae), which frequently leads to coral mortality. Remote sensing of sea surface temperature (SST) has served as an invaluable tool for monitoring physical conditions that can lead to bleaching events over relatively large scales (e.g. few kms to 100 s of kms). But, it is also well known that seawater temperatures within a site can vary significantly across depths due to the combined influence of solar heating of surface waters, water column thermal stratification, and cooling from internal waves and upwelling. We deployed small autonomous benthic temperature sensors at depths ranging from 0–40 m in fore reef, back reef, and lagoonal reef habitats on the Belize Mesoamerican Barrier Reef System from 2000–2019. These data can be used to calculate depth-specific climatologies across reef depths and sites, and emphasize the dynamic and spatially-variable nature of coral reef physical environments., Measurement(s) temperature of water Technology Type(s) Temperature Sensor Device Factor Type(s) temporal interval • geographic location • depth Sample Characteristic - Environment sea • marine reef • coral reef • marine coral reef back reef • marine coral reef fore reef Sample Characteristic - Location Belize Barrier Reef Machine-accessible metadata file describing the reported data: 10.6084/m9.figshare.13095506
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- 2020
32. Global land use for 2015–2100 at 0.05° resolution under diverse socioeconomic and climate scenarios
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Maoyi Huang, Katherine Calvin, Mohamad Hejazi, Yanyan Cheng, Chris R. Vernon, Min Chen, and N. T. Graham
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Statistics and Probability ,Data Descriptor ,010504 meteorology & atmospheric sciences ,Land use ,Global change ,Representative Concentration Pathways ,Forcing (mathematics) ,Land cover ,010501 environmental sciences ,Library and Information Sciences ,01 natural sciences ,Projection and prediction ,Computer Science Applications ,Education ,Earth system science ,Metadata ,Climatology ,Environmental science ,lcsh:Q ,Statistics, Probability and Uncertainty ,lcsh:Science ,Climate and Earth system modelling ,0105 earth and related environmental sciences ,Information Systems ,Downscaling - Abstract
Global future land use (LU) is an important input for Earth system models for projecting Earth system dynamics and is critical for many modeling studies on future global change. Here we generated a new global gridded LU dataset using the Global Change Analysis Model (GCAM) and a land use spatial downscaling model, named Demeter, under the five Shared Socioeconomic Pathways (SSPs) and four Representative Concentration Pathways (RCPs) scenarios. Compared to existing similar datasets, the presented dataset has a higher spatial resolution (0.05° × 0.05°) and spreads under a more comprehensive set of SSP-RCP scenarios (in total 15 scenarios), and considers uncertainties from the forcing climates. We compared our dataset with the Land Use Harmonization version 2 (LUH2) dataset and found our results are in general spatially consistent with LUH2. The presented dataset will be useful for global Earth system modeling studies, especially for the analysis of the impacts of land use and land cover change and socioeconomics, as well as the characterizing the uncertainties associated with these impacts., Measurement(s) land use process • global land use and land cover Technology Type(s) computational modeling technique Factor Type(s) year of data collection • Shared Socioeconomic Pathways scenarios • Representative Concentration Pathways scenarios Sample Characteristic - Environment land Sample Characteristic - Location Earth (planet) Machine-accessible metadata file describing the reported data: 10.6084/m9.figshare.12967760
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- 2020
33. Global warming due to loss of large ice masses and Arctic summer sea ice
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Ricarda Winkelmann, Jonathan F. Donges, Nico Wunderling, and Matteo Willeit
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0301 basic medicine ,Cryospheric science ,010504 meteorology & atmospheric sciences ,Science ,General Physics and Astronomy ,Antarctic ice sheet ,01 natural sciences ,General Biochemistry, Genetics and Molecular Biology ,Article ,Projection and prediction ,03 medical and health sciences ,Sea ice ,Cryosphere ,lcsh:Science ,Climate and Earth system modelling ,0105 earth and related environmental sciences ,geography ,Multidisciplinary ,geography.geographical_feature_category ,Global warming ,Glacier ,General Chemistry ,Albedo ,030104 developmental biology ,Arctic ,Climatology ,Environmental science ,lcsh:Q ,Ice sheet - Abstract
Several large-scale cryosphere elements such as the Arctic summer sea ice, the mountain glaciers, the Greenland and West Antarctic Ice Sheet have changed substantially during the last century due to anthropogenic global warming. However, the impacts of their possible future disintegration on global mean temperature (GMT) and climate feedbacks have not yet been comprehensively evaluated. Here, we quantify this response using an Earth system model of intermediate complexity. Overall, we find a median additional global warming of 0.43 °C (interquartile range: 0.39−0.46 °C) at a CO2 concentration of 400 ppm. Most of this response (55%) is caused by albedo changes, but lapse rate together with water vapour (30%) and cloud feedbacks (15%) also contribute significantly. While a decay of the ice sheets would occur on centennial to millennial time scales, the Arctic might become ice-free during summer within the 21st century. Our findings imply an additional increase of the GMT on intermediate to long time scales., The disintegration of cryosphere elements such as the Arctic summer sea ice, mountain glaciers, Greenland and West Antarctica is associated with temperature and radiative feedbacks. In this work, the authors quantify these feedbacks and find an additional global warming of 0.43°C.
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- 2020
34. Fusing subnational with national climate action is central to decarbonization: the case of the United States
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John O’Neill, Wendy Jaglom, Tom Cyrs, Leon Clarke, Andrew Clapper, Jessie Lund, Christina Bowman, J. C. Altimirano, Kristin Igusky, Nathan E. Hultman, Morgan R. Edwards, Jiehong Lou, Kevin Kennedy, Carla Frisch, Pete Hansel, Ryna Cui, Margaret Dennis, Gill Zwicker, James DeWeese, Koben Calhoun, Joel Jaeger, Devashree Saha, Arijit Sen, Paul Bodnar, Haewon McJeon, Kareem Hammoud, Chris Henderson, Michael I. Westphal, and Michelle Manion
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Natural resource economics ,media_common.quotation_subject ,Science ,action plan ,General Physics and Astronomy ,business development ,global warming ,050601 international relations ,General Biochemistry, Genetics and Molecular Biology ,Article ,State (polity) ,emission control ,strategic approach ,environmental policy ,050602 political science & public administration ,lcsh:Science ,federal system ,Climate-change mitigation ,Climate and Earth system modelling ,media_common ,Potential impact ,Socioeconomic scenarios ,Multidisciplinary ,05 social sciences ,Climate-change policy ,General Chemistry ,0506 political science ,climate change ,Action (philosophy) ,international agreement ,lcsh:Q ,environmental economics ,Business ,Energy policy - Abstract
Approaches that root national climate strategies in local actions will be essential for all countries as they develop new nationally determined contributions under the Paris Agreement. The potential impact of climate action from non-national actors in delivering higher global ambition is significant. Sub-national action in the United States provides a test for how such actions can accelerate emissions reductions. We aggregated U.S. state, city, and business commitments within an integrated assessment model to assess how a national climate strategy can be built upon non-state actions. We find that existing commitments alone could reduce emissions 25% below 2005 levels by 2030, and that enhancing actions by these actors could reduce emissions up to 37%. We show how these actions can provide a stepped-up basis for additional federal action to reduce emissions by 49%—consistent with 1.5 °C. Our analysis demonstrates sub-national actions can lead to substantial reductions and support increased national action., Climate action from local actors is vital in achieving nationally determined contributions under the Paris Agreement. Here the authors show that existing commitments from U.S. states, cities and business could reduce emissions 25% below 2005 levels by 2030, with expanded subnational action reducing emissions by 37% and federal action by up to 49%.
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- 2020
35. Robust but weak winter atmospheric circulation response to future Arctic sea ice loss
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D. M. Smith, R. Eade, M. B. Andrews, H. Ayres, A. Clark, S. Chripko, C. Deser, N. J. Dunstone, J. García-Serrano, G. Gastineau, L. S. Graff, S. C. Hardiman, B. He, L. Hermanson, T. Jung, J. Knight, X. Levine, G. Magnusdottir, E. Manzini, D. Matei, M. Mori, R. Msadek, P. Ortega, Y. Peings, A. A. Scaife, J. A. Screen, M. Seabrook, T. Semmler, M. Sigmond, J. Streffing, L. Sun, A. Walsh, Barcelona Supercomputing Center, Met Office Hadley Centre for Climate Change (MOHC), United Kingdom Met Office [Exeter], Department of Meteorology [Reading], University of Reading (UOR), Centre Européen de Recherche et de Formation Avancée en Calcul Scientifique (CERFACS), National Center for Atmospheric Research [Boulder] (NCAR), Universitat de Barcelona (UB), Océan et variabilité du climat (VARCLIM), Laboratoire d'Océanographie et du Climat : Expérimentations et Approches Numériques (LOCEAN), Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Norwegian Meteorological Institute [Oslo] (MET), Institute of Atmospheric Physics [Beijing] (IAP), Chinese Academy of Sciences [Beijing] (CAS), Alfred Wegener Institute [Potsdam], Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung (AWI), Barcelona Supercomputing Center - Centro Nacional de Supercomputacion (BSC - CNS), Department of Earth System Science [Irvine] (ESS), University of California [Irvine] (UC Irvine), University of California (UC)-University of California (UC), Max-Planck-Institut für Meteorologie (MPI-M), Max-Planck-Gesellschaft, Research Institute for Applied Mechanics [Fukuoka] (RIAM), Kyushu University, College of Engineering, Mathematics and Physical Sciences [Exeter] (EMPS), University of Exeter, Canadian Centre for Climate Modelling and Analysis (CCCma), Environment and Climate Change Canada, Department of Atmospheric Science [Fort Collins], Colorado State University [Fort Collins] (CSU), European Project: 727852,Blue-Action(2016), and European Project: 727862,APPLICATE
- Subjects
Atmospheric dynamics ,Multidisciplinary ,Sea ice--Arctic regions ,Science ,General Physics and Astronomy ,[PHYS.PHYS.PHYS-GEO-PH]Physics [physics]/Physics [physics]/Geophysics [physics.geo-ph] ,General Chemistry ,General Biochemistry, Genetics and Molecular Biology ,Climate Action ,Atmospheric circulation ,Environmental health ,North Atlantic oscillation ,Simulació per ordinador ,Enginyeria agroalimentària::Ciències de la terra i de la vida [Àrees temàtiques de la UPC] ,Climate and Earth system modelling - Abstract
The possibility that Arctic sea ice loss weakens mid-latitude westerlies, promoting more severe cold winters, has sparked more than a decade of scientific debate, with apparent support from observations but inconclusive modelling evidence. Here we show that sixteen models contributing to the Polar Amplification Model Intercomparison Project simulate a weakening of mid-latitude westerlies in response to projected Arctic sea ice loss. We develop an emergent constraint based on eddy feedback, which is 1.2 to 3 times too weak in the models, suggesting that the real-world weakening lies towards the higher end of the model simulations. Still, the modelled response to Arctic sea ice loss is weak: the North Atlantic Oscillation response is similar in magnitude and offsets the projected response to increased greenhouse gases, but would only account for around 10% of variations in individual years. We further find that relationships between Arctic sea ice and atmospheric circulation have weakened recently in observations and are no longer inconsistent with those in models. D.M.S., R.E., L.H., L.S.G., T.J., T.S., X.L., and P.O. were supported by the EU H2020 APPLICATE project (GA727862). The Met Office contribution was also supported by the Met Office Hadley Centre Climate Programme funded by BEIS and Defra and by the UK-China Research and Innovation Partnership Fund through the Met Office Climate Science for Service Partnership (CSSP) China as part of the Newton Fund. J.A.S was supported by NERC grants NE/P006760/1, NE/R005125/1 and NE/V005855/1. G.M and Y.P. were supported by the US Department of Energy, grant number DE-SC0019407. L.S.G was also supported by the Research council of Norway INES project (270061), and the Norwegian e-infrastructure for Research and Education (UNINETT Sigma2) through projects NN2345K, NS2345K and NS9034K. E.M. and D.M. acknowledge the support of the German Federal Ministry of Education and Research through the JPI Climate/JPI Oceans NextG-Climate Science-ROADMAP (FKZ: 01LP2002A) project and of the European Union’s Horizon 2020 Programme through the Blue-Action Project (GA727852); and the use of resources from the DKRZ bm0966 and bm1190 projects. C. Deser acknowledges support from the National Center for Atmospheric Research, which is a major facility sponsored by the US National Science Foundation under cooperative agreement 1852977. M.M. was supported by MEXT through the Integrated Research Program for Advancing Climate Models (JPMXD0717935457) and ArCS II (JPMXD1420318865) programs, and by the Environment Research and Technology Development Fund (JPMEERF20192004). J.G.-S. and P.O. were supported by the Spanish Ramón y Cajal’ programme (RYC-2016-21181, RYC-2016-22772). B.H. was jointly funded by the Strategic Priority Research Program of the Chinese Academy of Sciences (Grant No. XDA19070404) and the National Natural Science Foundation of China (Grant Nos. 42030602, 91837101). G.G. was supported by the EU H2020 Blue–Action (GA727852) project and uses the HPC resources of TGCC under the allocations 2018-R0040110492 and 2019-A0060107732 made by GENCI. J.S. acknowledges the project L4 of the Collaborative Research Centre TRR 181 Energy Transfers in Atmosphere and Ocean funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) under Project 274762653. Peer Reviewed "Article signat per 31 autors/es: D. M. Smith, R. Eade, M. B. Andrews, H. Ayres, A. Clark, S. Chripko, C. Deser, N. J. Dunstone, J. García-Serrano, G. Gastineau, L. S. Graff, S. C. Hardiman, B. He, L. Hermanson, T. Jung, J. Knight, X. Levine, G. Magnusdottir, E. Manzini, D. Matei, M. Mori, R. Msadek, P. Ortega, Y. Peings, A. A. Scaife, J. A. Screen, M. Seabrook, T. Semmler, M. Sigmond, J. Streffing, L. Sun & A. Walsh "
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- 2022
36. Microscale drivers of summer CO2 fluxes in the Svalbard High Arctic tundra
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Magnani M.[1, Baneschi I.[3], Giamberini M.[3], Raco B.[3], and Provenzale A.[3]
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Multidisciplinary ,tundra ,Ecosystem respiration ,Science ,perma frost carbon ,ny-alesund ,species composition ,seasonal dynamics ,glacier foreland ,active layer ,area index ,leaf-area ,exchange ,vegetation ,Carbon cycle ,Gross primary productivity ,Article ,Arctic ,Medicine ,Carbon fluxes ,flux chamber ,Climate and Earth system modelling - Abstract
High-Arctic ecosystems are strongly affected by climate change, and it is still unclear whether they will become a carbon source or sink in the next few decades. In turn, such knowledge gaps on the drivers and the processes controlling CO2 fluxes and storage make future projections of the Arctic carbon budget a challenging goal. During summer 2019, we extensively measured CO2 fluxes at the soil–vegetation–atmosphere interface, together with basic meteoclimatic variables and ecological characteristics in the Bayelva river basin near Ny Ålesund, Spitzbergen, Svalbard (NO). By means of multi-regression models, we identified the main small-scale drivers of CO2 emission (Ecosystem Respiration, ER), and uptake (Gross Primary Production, GPP) in this tundra biome, showing that (i) at point scale, the temporal variability of fluxes is controlled by the classical drivers, i.e. air temperature and solar irradiance respectively for ER and GPP, (ii) at site scale, the heterogeneity of fractional vegetation cover, soil moisture and vegetation type acted as additional source of variability for both CO2 emissions and uptake. The assessment of the relative importance of such drivers in the multi-regression model contributes to a better understanding of the terrestrial carbon dioxide exchanges and of Critical Zone processes in the Arctic tundra.
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- 2022
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37. Hybrid systems using residual modeling for sea surface temperature forecasting
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de Mattos Neto, Paulo S. G., Cavalcanti, George D. C., de O. Santos Júnior, Domingos S., and Silva, Eraylson G.
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Multidisciplinary ,Science ,Atmospheric science ,Climate change ,Medicine ,Climate and Earth system modelling ,Computer science ,Article ,Projection and prediction - Abstract
The sea surface temperature (SST) is an environmental indicator closely related to climate, weather, and atmospheric events worldwide. Its forecasting is essential for supporting the decision of governments and environmental organizations. Literature has shown that single machine learning (ML) models are generally more accurate than traditional statistical models for SST time series modeling. However, the parameters tuning of these ML models is a challenging task, mainly when complex phenomena, such as SST forecasting, are addressed. Issues related to misspecification, overfitting, or underfitting of the ML models can lead to underperforming forecasts. This work proposes using hybrid systems (HS) that combine (ML) models using residual forecasting as an alternative to enhance the performance of SST forecasting. In this context, two types of combinations are evaluated using two ML models: support vector regression (SVR) and long short-term memory (LSTM). The experimental evaluation was performed on three datasets from different regions of the Atlantic Ocean using three well-known measures: mean square error (MSE), mean absolute percentage error (MAPE), and mean absolute error (MAE). The best HS based on SVR improved the MSE value for each analyzed series by $$82.26\%$$ 82.26 % , $$98.93\%$$ 98.93 % , and $$65.03\%$$ 65.03 % compared to its respective single model. The HS employing the LSTM improved $$92.15\%$$ 92.15 % , $$98.69\%$$ 98.69 % , and $$32.41\%$$ 32.41 % concerning the single LSTM model. Compared to literature approaches, at least one version of HS attained higher accuracy than statistical and ML models in all study cases. In particular, the nonlinear combination of the ML models obtained the best performance among the proposed HS versions.
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- 2022
38. Responsibility of major emitters for country-level warming and extreme hot years
- Author
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Beusch, Lea, Nauels, Alexander, Gudmundsson, Lukas, Gütschow, Johannes, Schleussner, Carl-Friedrich, and Seneviratne, Sonia I.
- Subjects
Attribution ,Climate and Earth system modelling ,Climate-change impacts ,Climate-change mitigation ,Projection and prediction - Abstract
The contributions of single greenhouse gas emitters to country-level climate change are generally not disentangled, despite their relevance for climate policy and litigation. Here, we quantify the contributions of the five largest emitters (China, US, EU-27, India, and Russia) to projected 2030 country-level warming and extreme hot years with respect to pre-industrial climate using an innovative suite of Earth System Model emulators. We find that under current pledges, their cumulated 1991-2030 emissions are expected to result in extreme hot years every second year by 2030 in twice as many countries (92%) as without their influence (46%). If all world nations shared the same fossil CO2 per capita emissions as projected for the US from 2016-2030, global warming in 2030 would be 0.4 °C higher than under actual current pledges, and 75% of all countries would exceed 2 °C of regional warming instead of 11%. Our results highlight the responsibility of individual emitters in driving regional climate change and provide additional angles for the climate policy discourse. ISSN:2662-4435
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- 2022
39. Vegetation type is an important predictor of the arctic summer land surface energy budget
- Author
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Oehri, Jacqueline, Schaepman-Strub, Gabriela, Kim, Jin-Soo, Grysko, Raleigh, Kropp, Heather, Grünberg, Inge, Zemlianskii, Vitalii, Sonnentag, Oliver, Euskirchen, Eugénie S., Reji Chacko, Merin, Muscari, Giovanni, Blanken, Peter D., Dean, Joshua F., di Sarra, Alcide, Harding, Richard J., Sobota, Ireneusz, Kutzbach, Lars, Plekhanova, Elena, Riihelä, Aku, Boike, Julia, Miller, Nathaniel B., Beringer, Jason, López-Blanco, Efrén, Stoy, Paul C., Sullivan, Ryan C., Kejna, Marek, Parmentier, Frans-Jan W., Gamon, John A., Mastepanov, Mikhail, Wille, Christian, Jackowicz-Korczynski, Marcin, Karger, Dirk N., Quinton, William L., Putkonen, Jaakko, van As, Dirk, Christensen, Torben R., Hakuba, Maria Z., Stone, Robert S., Metzger, Stefan, Vandecrux, Baptiste, Frost, Gerald V., Wild, Martin, Hansen, Birger, Meloni, Daniela, Domine, Florent, te Beest, Mariska, Sachs, Torsten, Kalhori, Aram, Rocha, Adrian V., Williamson, Scott N., Morris, Sara, Atchley, Adam L., Essery, Richard, Runkle, Benjamin R. K., Holl, David, Riihimaki, Laura D., Iwata, Hiroki, Schuur, Edward A. G., Cox, Christopher J., Grachev, Andrey A., McFadden, Joseph P., Fausto, Robert S., Göckede, Mathias, Ueyama, Masahito, Pirk, Norbert, de Boer, Gijs, Bret-Harte, M. Syndonia, Leppäranta, Matti, Steffen, Konrad, Friborg, Thomas, Ohmura, Atsumu, Edgar, Colin W., Olofsson, Johan, Chambers, Scott D., Environmental Sciences, Afd Marine and Atmospheric Research, Spatial Ecology and Global Change, Sub Algemeen Marine & Atmospheric Res, Institute for Atmospheric and Earth System Research (INAR), Environmental Sciences, Afd Marine and Atmospheric Research, Spatial Ecology and Global Change, and Sub Algemeen Marine & Atmospheric Res
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Climate Research ,Climate Change ,General Physics and Astronomy ,Feedbacks ,Permafrost ,General Biochemistry, Genetics and Molecular Biology ,Ecosystems ,Ecology and Environment ,Klimatforskning ,Meteorology and Climatology ,Snow ,Exchanges ,Boreal forest ,Variability ,Tundra ,Climate and Earth system modelling ,1172 Environmental sciences ,Ecosystem ,Atmospheric dynamics ,Multidisciplinary ,Arctic Regions ,cryosperic science ,ecosystem ecology ,General Chemistry ,Fluxes ,Phenology ,Carbon-dioxide ,Seasons - Abstract
Despite the importance of high-latitude surface energy budgets (SEBs) for land-climate interactions in the rapidly changing Arctic, uncertainties in their prediction persist. Here, we harmonize SEB observations across a network of vegetated and glaciated sites at circumpolar scale (1994-2021). Our variance-partitioning analysis identifies vegetation type as an important predictor for SEB-components during Arctic summer (June-August), compared to other SEB-drivers including climate, latitude and permafrost characteristics. Differences among vegetation types can be of similar magnitude as between vegetation and glacier surfaces and are especially high for summer sensible and latent heat fluxes. The timing of SEB-flux summer-regimes (when daily mean values exceed 0 Wm(-2)) relative to snow-free and -onset dates varies substantially depending on vegetation type, implying vegetation controls on snow-cover and SEB-flux seasonality. Our results indicate complex shifts in surface energy fluxes with land-cover transitions and a lengthening summer season, and highlight the potential for improving future Earth system models via a refined representation of Arctic vegetation types.An international team of researchers finds high potential for improving climate projections by a more comprehensive treatment of largely ignored Arctic vegetation types, underscoring the importance of Arctic energy exchange measuring stations.
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- 2022
40. Dominant controls of cold-season precipitation variability over the high mountains of Asia
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Shahid Mehmood, Moetasim Ashfaq, Sarah Kapnick, Subimal Gosh, Muhammad Adnan Abid, Fred Kucharski, Fulden Batibeniz, Anamitra Saha, Katherine Evans, and Huang-Hsiung Hsu
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Atmospheric Science ,Global and Planetary Change ,Atmospheric dynamics ,Statistics ,FOS: Mathematics ,Environmental Chemistry ,Climate and Earth system modelling - Abstract
A robust understanding of the sub-seasonal cold season (November–March) precipitation variability over the High Mountains of Asia (HMA) is lacking. Here, we identify dynamic and thermodynamic pathways through which natural modes of climate variability establish their teleconnections over the HMA. First, we identify evaporative sources that contribute to the cold season precipitation over the HMA and surrounding areas. The predominant moisture contribution comes from the mid-latitude regions, including the Mediterranean/Caspian Seas and Mediterranean land. Second, we establish that several tropical and extratropical forcings display a sub-seasonally fluctuating influence on precipitation distribution over the region during the cold season. Many of them varyingly interact, so their impacts cannot be explained independently or at seasonal timescales. Lastly, a single set of evaporative sources is not identifiable as the key determinant in propagating a remote teleconnection because the sources of moisture anomalies depend on the pattern of sub-seasonally varying dynamical forcing in the atmosphere., npj Climate and Atmospheric Science, 5 (1), ISSN:2397-3722
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- 2022
- Full Text
- View/download PDF
41. A joint role for forced and internally-driven variability in the decadal modulation of global warming
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Gerald A. Meehl, Martin S. Singh, Julie M. Arblaster, Shayne McGregor, Giovanni Liguori, Liguori G., McGregor S., Arblaster J.M., Singh M.S., and Meehl G.A.
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climate variability ,010504 meteorology & atmospheric sciences ,Science ,General Physics and Astronomy ,Forcing (mathematics) ,global warming ,010502 geochemistry & geophysics ,01 natural sciences ,General Biochemistry, Genetics and Molecular Biology ,Article ,Projection and prediction ,Modulation (music) ,Atmospheric science ,Climate change ,Mean radiant temperature ,Time series ,lcsh:Science ,Climate and Earth system modelling ,global mean sea surface temperature ,0105 earth and related environmental sciences ,geography ,Multidisciplinary ,geography.geographical_feature_category ,Global warming ,General Chemistry ,climate modelling ,Earth system science ,Sea surface temperature ,Volcano ,Climatology ,Environmental science ,lcsh:Q ,decadal variability - Abstract
Despite the observed monotonic increase in greenhouse-gas concentrations, global mean temperature displays important decadal fluctuations typically attributed to both external forcing and internal variability. Here, we provide a robust quantification of the relative contributions of anthropogenic, natural, and internally-driven decadal variability of global mean sea surface temperature (GMSST) by using a unique dataset consisting of 30-member large initial-condition ensembles with five Earth System Models (ESM-LE). We present evidence that a large fraction (~29–53%) of the simulated decadal-scale variance in individual timeseries of GMSST over 1950–2010 is externally forced and largely linked to the representation of volcanic aerosols. Comparison with the future (2010–2070) period suggests that external forcing provides a source of additional decadal-scale variability in the historical period. Given the unpredictable nature of future volcanic aerosol forcing, it is suggested that a large portion of decadal GMSST variability might not be predictable., Global mean sea surface surface temperature shows decadal fluctuations superimposed to the warming trend whose causes are still debated. Here, the authors provide a quantification of relative contributions of different drivers and conclude that both internal and externally-forced variability play a comparable role.
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- 2020
42. Different precipitation response over land and ocean to orbital and greenhouse gas forcing
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Chetankumar Jalihal, Arindam Chakraborty, and J. Srinivasan
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0301 basic medicine ,Atmospheric dynamics ,Multidisciplinary ,010504 meteorology & atmospheric sciences ,Orbital forcing ,lcsh:R ,lcsh:Medicine ,Forcing (mathematics) ,Palaeoclimate ,Monsoon ,Atmospheric sciences ,01 natural sciences ,Article ,03 medical and health sciences ,030104 developmental biology ,Complex response ,Latent heat ,Abrupt climate change ,Environmental science ,Climate model ,lcsh:Q ,Precipitation ,lcsh:Science ,Climate and Earth system modelling ,0105 earth and related environmental sciences - Abstract
Various proxies suggest a nearly in-phase variation of monsoons with local summer insolation. Oceanic proxies of monsoons document a more complex response. Climate model simulations also indicate that the response is different over land and ocean. Here using a transient simulation by a climate model over the last 22,000 years we have unraveled the factors that lead to these differences within the Indian subcontinent. We show that during the deglacial (22–12 ka) precipitation over India and the Bay of Bengal (BoB) are in phase, whereas they are out of phase across the Holocene (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\sim$$\end{document}∼ 12 ka to 0 ka). During the deglacial, water vapor amplifies the effect of solar forcing on precipitation over both the regions, whereas contributions from surface latent heat fluxes over the BoB drive an opposite response across the Holocene. We find that greenhouse gas forcing drives similar precipitation response over land and ocean, whereas orbital forcing produces a different response over land and ocean. We have further demonstrated that during periods of abrupt climate change [such as the Bølling–Allerød (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\sim$$\end{document}∼ 14 ka)], water vapor affects precipitation mainly through its influence on the vertical stability of the atmosphere. These results highlight the complex nature of precipitation over the BoB and thus has implications for the interpretation of monsoon proxies.
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- 2020
43. The role of biomass burning states in light absorption enhancement of carbonaceous aerosols
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Xiaole Pan, Tianhai Cheng, Hang Liu, Shuaiyi Shi, Yu Wu, and Lijuan Zheng
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Earth's energy budget ,Smouldering ,Multidisciplinary ,010504 meteorology & atmospheric sciences ,lcsh:R ,lcsh:Medicine ,Carbon black ,010501 environmental sciences ,Radiative forcing ,Atmospheric sciences ,Combustion ,01 natural sciences ,Article ,Aerosol ,Environmental impact ,Particle ,Environmental science ,lcsh:Q ,Absorption (electromagnetic radiation) ,lcsh:Science ,Climate and Earth system modelling ,0105 earth and related environmental sciences - Abstract
Carbonaceous aerosols, which are emitted from biomass burning, significantly contribute to the Earth’s radiation balance. Radiative forcing caused by biomass burning has been poorly qualified, which is largely attributed to uncertain absorption enhancement values (Eabs) of black carbon (BC) aerosols. Laboratory measurements and theoretical modelling indicate a significant value of Eabs; but this enhancement is observed to be negligible in the ambient environment, implying that models may overestimate global warming due to BC. Here, we present an aggregate model integrating BC aerosol ensembles with different morphologies and mixing states and report a quantitative analysis of the BC Eabs from different combustion states during biomass burning. We show that the BC Eabs produced by flaming combustion may be up to two times more than those produced by smouldering combustion, suggesting that the particle morphology and mixing state of freshly emitted BC aerosols is an important source of the contrasting values of Eabs. The particle morphology of freshly emitted BC aerosols is widely assumed to be bare in models, which is rare in the ambient environment and leads to small estimates of Eabs by field observations. We conclude that the exact description of freshly emitted carbonaceous aerosols plays an important role in constraining aerosol radiative forcing.
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- 2020
44. Relationship between biometeorological factors and the number of hospitalizations due to asthma
- Author
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Anna Doboszyńska, Ewa Dragańska, Anna Romaszko-Wojtowicz, Katarzyna Glińska-Lewczuk, Iwona Cymes, and Jerzy Romaszko
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Male ,Meteorological Concepts ,010504 meteorology & atmospheric sciences ,Climate ,lcsh:Medicine ,010501 environmental sciences ,01 natural sciences ,Article ,Meteorology ,Air Pollution ,Environmental health ,Humans ,Medicine ,In patient ,lcsh:Science ,Climate and Earth system modelling ,Air quality index ,Aged ,Retrospective Studies ,0105 earth and related environmental sciences ,Asthma ,Aerosols ,Air Pollutants ,Multidisciplinary ,Asthma exacerbations ,business.industry ,Incidence (epidemiology) ,lcsh:R ,Patient data ,Relative air humidity ,Prognosis ,medicine.disease ,Climate index ,respiratory tract diseases ,Hospitalization ,Female ,lcsh:Q ,Poland ,business ,Follow-Up Studies - Abstract
The incidence of asthma exacerbation depends on atmospheric conditions, including such meteorological factors as the ambient temperature, relative air humidity or concentration of atmospheric aerosols. An assessment of relations between the frequency of asthma exacerbation and environmental conditions was made according to the meteorological components, the biometeorological index UTCI (Universal Thermal Climate Index), as well as selected air quality parameters, including concentrations of PM10 and PM2.5. The study was conducted on the basis of a retrospective analysis of medical data collected at the Independent Public Hospital of Tuberculosis and Pulmonary Diseases in Olsztyn (Poland). Our analysis of patient data (from 1 January 2013 until 31 December 2017) showed a significant correlation between the number of asthma exacerbation and the UTCI value. More frequent asthma exacerbations are observed in patients aged over 65 years when air humidity increases. The UTCI values contained within class 5, describing thermoneutral conditions, correspond to an average frequency of asthma exacerbation. A decline in the UTCI value leads to a reduced number of asthma exacerbation, while a rise makes the cases of asthma exacerbations increase.
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- 2020
45. Causal networks for climate model evaluation and constrained projections
- Author
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Veronika Eyring, Peer Nowack, Joanna D. Haigh, and Jakob Runge
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0301 basic medicine ,010504 meteorology & atmospheric sciences ,Computer science ,Datenmanagement und Analyse ,IMPACT ,General Physics and Astronomy ,UNCERTAINTY ,causal networks ,ATMOSPHERIC TELECONNECTIONS ,Metrics ,01 natural sciences ,Proxy (climate) ,Machine Learning ,constrained projections ,lcsh:Science ,media_common ,Multidisciplinary ,Environmental resource management ,climate model evaluation ,METRICS ,Causality ,Multidisciplinary Sciences ,General Circulation Model ,FEEDBACKS ,Science & Technology - Other Topics ,media_common.quotation_subject ,Science ,Climate Change ,CIRCULATION ,Climate change ,ENSEMBLE ,General Biochemistry, Genetics and Molecular Biology ,Article ,Projection and prediction ,03 medical and health sciences ,Atmospheric science ,East Asia ,CMIP5 ,Erdsystemmodell -Evaluation und -Analyse ,Climate and Earth system modelling ,0105 earth and related environmental sciences ,Science & Technology ,business.industry ,Atmosphere ,Storm ,General Chemistry ,PERFORMANCE ,Interdependence ,030104 developmental biology ,Climate model ,lcsh:Q ,business ,ENSO TELECONNECTIONS ,Climate sciences - Abstract
Global climate models are central tools for understanding past and future climate change. The assessment of model skill, in turn, can benefit from modern data science approaches. Here we apply causal discovery algorithms to sea level pressure data from a large set of climate model simulations and, as a proxy for observations, meteorological reanalyses. We demonstrate how the resulting causal networks (fingerprints) offer an objective pathway for process-oriented model evaluation. Models with fingerprints closer to observations better reproduce important precipitation patterns over highly populated areas such as the Indian subcontinent, Africa, East Asia, Europe and North America. We further identify expected model interdependencies due to shared development backgrounds. Finally, our network metrics provide stronger relationships for constraining precipitation projections under climate change as compared to traditional evaluation metrics for storm tracks or precipitation itself. Such emergent relationships highlight the potential of causal networks to constrain longstanding uncertainties in climate change projections., Algorithms to assess causal relationships in data sets have seen increasing applications in climate science in recent years. Here, the authors show that these techniques can help to systematically evaluate the performance of climate models and, as a result, to constrain uncertainties in future climate change projections.
- Published
- 2020
46. Identifying a human signal in the North Atlantic warming hole
- Author
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Lorenzo M. Polvani, Rei Chemke, and Laure Zanna
- Subjects
0301 basic medicine ,Multidisciplinary ,010504 meteorology & atmospheric sciences ,Science ,Northern Hemisphere ,General Physics and Astronomy ,General Chemistry ,01 natural sciences ,Article ,General Biochemistry, Genetics and Molecular Biology ,Attribution ,03 medical and health sciences ,030104 developmental biology ,Greenhouse gas ,Middle latitudes ,Climatology ,Climate change ,Environmental science ,Climate model ,lcsh:Q ,lcsh:Science ,Climate and Earth system modelling ,0105 earth and related environmental sciences - Abstract
North Atlantic sea surface temperatures have large climate impacts affecting the weather of the Northern Hemisphere. In addition to a substantial warming over much of the North Atlantic, caused by increasing greenhouse gases over the 21st century, climate projections show a surprising region of considerable future cooling at midlatitudes, referred to as the North Atlantic warming hole. A similar pattern of surface temperature trends has been observed in recent decades, but it remains unclear whether this pattern is of anthropogenic origin or a simple manifestation of internal climate variability. Here, analyzing state-of-the-art climate models and observations, we show that the recent North Atlantic warming hole is of anthropogenic origin. Our analysis reveals that the anthropogenic signal has only recently emerged from the internal climate variability, and can be attributed to greenhouse gas emissions. We further show that a declining northward oceanic heat flux in recent decades, which is linked to this surface temperature pattern, is also of anthropogenic origin., Most of the North Atlantic has seen strong increase in surface temperatures in recent decades, except for one region, which has been called the North Atlantic warming hole. Here, the authors employ detection and attribution techniques to show that this temperature pattern in recent decades is being caused by anthropogenic greenhouse gas emissions.
- Published
- 2020
47. Global warming changes tropical cyclone translation speed
- Author
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Il-Ju Moon, Munehiko Yamaguchi, Johnny C. L. Chan, Kohei Yoshida, and Ryo Mizuta
- Subjects
010504 meteorology & atmospheric sciences ,Slowdown ,Historical model ,Science ,0211 other engineering and technologies ,General Physics and Astronomy ,02 engineering and technology ,Translation (geometry) ,01 natural sciences ,Article ,General Biochemistry, Genetics and Molecular Biology ,Projection and prediction ,Latitude ,Atmospheric science ,Climate change ,lcsh:Science ,Climate and Earth system modelling ,0105 earth and related environmental sciences ,021110 strategic, defence & security studies ,Multidisciplinary ,Global warming ,General Chemistry ,Climatology ,Greenhouse gas ,Environmental science ,lcsh:Q ,Tropical cyclone - Abstract
Slow-moving tropical cyclones (TCs) can cause heavy rain because of their duration of influence. Combined with expected increase in rain rates associated with TCs in a warmer climate, there is growing interest in TC translation speed in the past and future. Here we present that a slowdown trend of the translation speed is not simulated for the period 1951–2011 based on historical model simulations. We also find that the annual-mean translation speed could increase under global warming. Although previous studies show large uncertainties in the future projections of TC characteristics, our model simulations show that the average TC translation speed at higher latitudes becomes smaller in a warmer climate, but the relative frequency of TCs at higher latitudes increases. Since the translation speed is much larger in the extratropics, the increase in the relative frequency of TCs at higher latitudes compensates the reduction of the translation speed there, leading to a global mean increase in TC translation speed., How the translation speed of tropical cyclones has changed in recent decades and will change in the future has been the subject of debate. Model results show that on average, they have not slowed down in the past, but despite a slowing of tropical cyclones at higher latitudes, a poleward shift in their mean track location causes a general speed up under high greenhouse gas emissions.
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- 2020
48. Role of climate variability in the potential predictability of tropical cyclone formation in tropical and subtropical western North Pacific Ocean
- Author
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Swadhin K. Behera, Yu-Lin K. Chang, and Yasumasa Miyazawa
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Multidisciplinary ,010504 meteorology & atmospheric sciences ,Tropical Eastern Pacific ,010505 oceanography ,Anomaly (natural sciences) ,lcsh:R ,Natural hazards ,lcsh:Medicine ,Subtropics ,Vorticity ,01 natural sciences ,Article ,Projection and prediction ,El Niño ,Climatology ,Natural hazard ,Environmental science ,lcsh:Q ,Tropical cyclone ,Predictability ,lcsh:Science ,Climate and Earth system modelling ,0105 earth and related environmental sciences - Abstract
The out of phase tropical cyclone (TC) formation in the subtropical and tropical western North Pacific associated with local low-level wind vorticity anomaly, driven by the remote central and eastern equatorial Pacific warming/cooling, is investigated based on the reanalysis and observational data in the period of 1979−2017. TC frequencies in the subtropical and tropical western North Pacific appear to be connected to different remote heating/cooling sources and are linked to eastern and central Pacific warming/cooling, which are in turn related to canonical El Niño/Southern Oscillation (ENSO) and ENSO Modoki, respectively. TCs formed in subtropics (SfTC) are generally found to be associated with a dipole in wind vorticity anomaly, which is driven by the tropical eastern Pacific warming/cooling. Tropically formed TCs (TfTC) are seen to be triggered by the single-core of wind vorticity anomaly locally associated with the warming/cooling of central and eastern Pacific. The predicted ENSOs and ENSO Modokis, therefore, provide a potential source of seasonal predictability for SfTC and TfTC frequencies.
- Published
- 2019
49. Snowfall Variability Dictates Glacier Mass Balance Variability in Himalaya-Karakoram
- Author
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Raghu Murtugudde, Pankaj Kumar, Aditya Kumar Dubey, Md. Saquib Saharwardi, Argha Banerjee, and Mohd Farooq Azam
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Cryospheric science ,geography ,education.field_of_study ,Multidisciplinary ,geography.geographical_feature_category ,010504 meteorology & atmospheric sciences ,0208 environmental biotechnology ,Population ,lcsh:R ,lcsh:Medicine ,Glacier ,02 engineering and technology ,Forcing (mathematics) ,Snow ,01 natural sciences ,Article ,020801 environmental engineering ,Glacier mass balance ,Climatology ,Environmental science ,lcsh:Q ,education ,lcsh:Science ,Climate and Earth system modelling ,0105 earth and related environmental sciences - Abstract
Glaciers in the Himalaya-Karakoram (HK) are critical for ensuring water-security of a large fraction of world’s population that is vulnerable to climate impacts. However, the sensitivity of HK glaciers to changes in meteorological forcing remains largely unknown. We analyzed modelled interannual variability of mass balance (MB) that is validated against available observations, to quantify the sensitivity of MB to meteorological factors over the HK. Within the model, snowfall variability (0.06 m/yr) explains ~60% of the MB variability (0.28 m/yr), implying a sensitivity of MB on snowfall to the tune of several hundreds of percent. This stunningly high sensitivity of MB to snowfall offers crucial insights into the mechanism of the recent divergent glacier response over the HK. Our findings underscore the need for sustained measurements and model representations of the spatiotemporal variability of snowfall, one of the least-studied factors over the glacierized HK, for capturing the large-scale and yet region-specific glacier changes taking place over the HK.
- Published
- 2019
50. Overestimated climate warming and climate variability due to spatially homogeneous CO2 in climate modeling over the Northern Hemisphere since the mid-19th century
- Author
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Xuezhen Zhang, Huijuan Cui, Deliang Chen, Xiaxiang Li, and Quansheng Ge
- Subjects
0301 basic medicine ,Multidisciplinary ,010504 meteorology & atmospheric sciences ,Global warming ,lcsh:R ,Northern Hemisphere ,Climate change ,lcsh:Medicine ,01 natural sciences ,Article ,Projection and prediction ,03 medical and health sciences ,La Niña ,030104 developmental biology ,Climatology ,Walker circulation ,Environmental science ,Spatial variability ,Climate model ,lcsh:Q ,Precipitation ,lcsh:Science ,Climate and Earth system modelling ,0105 earth and related environmental sciences - Abstract
Since the mid-19th century, the global atmospheric CO2 concentration (ACC) has increased dramatically due to the burning of fossil fuels. Because of unequal population growth and economic development among regions, the ACC increases possess strong spatial variability. Particularly, the increase in ACC has been larger in the mid-latitudes of the Northern Hemisphere (NH) than that at high- and low-latitudes. It is widely accepted that the ACC increase is the main reason for climate change, but the potential impacts of its spatial distribution on the climate system remain unclear. Therefore, we carried out two groups of 150-year experiments with the Community Earth System Model (CESM), using both spatially inhomogeneous (hereafter the SIC experiment) and homogenous (hereafter the SHC experiment) ACC increases in their settings. We found that the models’ divergences occurred over the NH mid-latitudes, the Arctic and the western part of the tropical Pacific. SHC overestimated (underestimated) climate warming over the Artic (mid-latitudes), which may be induced by the intensified westerly and weakened meridional heat exchange between mid- and high latitudes in the NH. Over the tropical Pacific, the overestimation of climate warming may be induced by intensified Walker circulation coupled with the La Niña climate mode. For the entire NH, relative to SIC, SHC overestimated the climate warming from 1850 to 1999 by ~10%. Meanwhile, the SHC experiment also overestimated the interannual variabilities in temperature and precipitation, resulting in more serious extreme events. These findings suggest that human contributions to climate warming and increased extreme events since the industrial revolution may be overestimated when using a spatially homogenous ACC.
- Published
- 2019
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