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2. Robust but weak winter atmospheric circulation response to future Arctic sea ice loss

Author

Smith, D. M., Eade, R., Andrews, M. B., Ayres, H., Clark, A., Chripko, S., Deser, C., Dunstone, N. J., García-Serrano, J., Gastineau, G., Graff, L. S., Hardiman, S. C., He, B., Hermanson, L., Jung, T., Knight, J., Levine, X., Magnusdottir, G., Manzini, E., Matei, D., Mori, M., Msadek, R., Ortega, P., Peings, Y., Scaife, A. A., Screen, J. A., Seabrook, M., Semmler, T., Sigmond, M., Streffing, J., Sun, L., and Walsh, A.

Published
2022
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3. Stratosphere-troposphere dynamical coupling

Author

Hardiman, S. C.

Subjects
551.5
Abstract

This thesis is concerned with dynamical coupling between the stratosphere and troposphere. The first part of the thesis examines mechanisms whereby dynamical perturbations to the upper stratosphere can lead to a significant response in the lower stratosphere, looking particularly at how this response is determined by the extra-tropical dynamics. A one dimensional model is used to show that the response is much greater when the external parameters are such that the flow has multiple stable states. The same principle is shown to apply to a fully three dimensional flow and does not depend qualitatively on the representation of the troposphere and tropospheric wave forcing. The dependence of the response on the height of the applied dynamical perturbation, the amplitude of planetary wave forcing, and the relaxation to radiative equilibrium temperatures is considered. In the second part of the thesis we consider the interhemispheric differences in the extratropical seasonal cycle and suggest that resonance of topographically forced waves with free travelling planetary waves could be in part responsible for these differences. The seasonal cycle in mass upwelling in the tropical lower stratosphere is also considered. In particular we look at the differences in this upwelling caused by the strength and location of tropospheric wave driving, the thermal relaxation timescale of the atmosphere, baroclinic instability, and the seasonal cycle in the tropospheric radiative equilibrium temperature field. Finally we consider the interannual variability seen in the tropical mass upwelling. We quantify the different parts of this variability – the part that can be considered forced variability and the part that arises due to internal variability. We suggest that the high forced variability seen in the mass upwelling may be due to it being linked, via extratropical wave driving, to sea surface temperatures.

Published
2007

5. Long-range prediction and the stratosphere

Author

Scaife, A. A., Baldwin, M. P., Butler, A. H., Charlton-Perez, A. J., Domeisen, D. I. V., Garfinkel, C.I., Hardiman, S. C., Haynes, P., Karpechko, A. Y., Lim, E.-P., Noguchi, S., Perlwitz, J., Polvani, L., Richter, J. H., Scinocca, J., Sigmond, M., Shepherd, T. G., Son, S.-W., and Thompson, D. W. J.

Abstract

Over recent years there have been concomitant advances in the development of stratosphere-resolving numerical models, our understanding of stratosphere–troposphere interaction, and the extension of long-range forecasts to explicitly include the stratosphere. These advances are now allowing for new and improved capability in long-range prediction. We present an overview of this development and show how the inclusion of the stratosphere in forecast systems aids monthly, seasonal, and annual-to-decadal climate predictions and multidecadal projections. We end with an outlook towards the future and identify areas of improvement that could\ud further benefit these rapidly evolving predictions.

Published
2022

7. Multimodel Estimates of Atmospheric Lifetimes of Long-Lived Ozone-Depleting Substances: Present and Future

Author

Chipperfield, M. P, Liang, Q, Strahan, S. E, Morgenstern, O, Dhomse, S. S, Abraham, N. L, Archibald, A. T, Bekki, S, Braesicke, P, Di Genova, G, Fleming, E. L, Hardiman, S. C, Iachetti, D, Jackman, C. H, Kinnison, D. E, Marchand, M, Pitari, G, Pyle, J. A, Rozanov, E, Stenke, A, and Tummon, F

Subjects
Meteorology And Climatology, Geophysics
Abstract

We have diagnosed the lifetimes of long-lived source gases emitted at the surface and removed in the stratosphere using six three-dimensional chemistry-climate models and a two-dimensional model. The models all used the same standard photochemical data. We investigate the effect of different definitions of lifetimes, including running the models with both mixing ratio (MBC) and flux (FBC) boundary conditions. Within the same model, the lifetimes diagnosed by different methods agree very well. Using FBCs versus MBCs leads to a different tracer burden as the implied lifetime contained in theMBC value does not necessarilymatch a model's own calculated lifetime. In general, there are much larger differences in the lifetimes calculated by different models, the main causes of which are variations in the modeled rates of ascent and horizontal mixing in the tropical midlower stratosphere. The model runs have been used to compute instantaneous and steady state lifetimes. For chlorofluorocarbons (CFCs) their atmospheric distribution was far from steady state in their growth phase through to the 1980s, and the diagnosed instantaneous lifetime is accordingly much longer. Following the cessation of emissions, the resulting decay of CFCs is much closer to steady state. For 2100 conditions the model circulation speeds generally increase, but a thicker ozone layer due to recovery and climate change reduces photolysis rates. These effects compensate so the net impact on modeled lifetimes is small. For future assessments of stratospheric ozone, use of FBCs would allow a consistent balance between rate of CFC removal and model circulation rate.

Published
2014
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10. Multimodel Assessment of the Factors Driving Stratospheric Ozone Evolution over the 21st Century

Author

Oman, L. D, Plummer, D. A, Waugh, D. W, Austin, J, Scinocca, J. F, Douglass, A. R, Salawitch, R. J, Canty, T, Akiyoshi, H, Bekki, S, Braesicke, P, Butchart, N, Chipperfield, M. P, Cugnet, D, Dhomse, S, Eyring, V, Frith, S, Hardiman, S. C, Kinnison, D. E, Lamarque, J.-F, Mancini, E, Marchand, M, Michou, M, Morgenstern, O, and Nakamura, T

Subjects
Geophysics
Abstract

The evolution of stratospheric ozone from 1960 to 2100 is examined in simulations from 14 chemistry-climate models, driven by prescribed levels of halogens and greenhouse gases. There is general agreement among the models that total column ozone reached a minimum around year 2000 at all latitudes, projected to be followed by an increase over the first half of the 21st century. In the second half of the 21st century, ozone is projected to continue increasing, level off, or even decrease depending on the latitude. Separation into partial columns above and below 20 hPa reveals that these latitudinal differences are almost completely caused by differences in the model projections of ozone in the lower stratosphere. At all latitudes, upper stratospheric ozone increases throughout the 21st century and is projected to return to 1960 levels well before the end of the century, although there is a spread among models in the dates that ozone returns to specific historical values. We find decreasing halogens and declining upper atmospheric temperatures, driven by increasing greenhouse gases, contribute almost equally to increases in upper stratospheric ozone. In the tropical lower stratosphere, an increase in upwelling causes a steady decrease in ozone through the 21st century, and total column ozone does not return to 1960 levels in most of the models. In contrast, lower stratospheric and total column ozone in middle and high latitudes increases during the 21st century, returning to 1960 levels well before the end of the century in most models.

Published
2010
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11. Using Transport Diagnostics to Understand Chemistry Climate Model Ozone Simulations

Author

Strahan, S. E, Douglass, A. R, Stolarski, R. S, Akiyoshi, H, Bekki, S, Braesicke, P, Butchart, N, Chipperfield, M. P, Cugnet, D, Dhomse, S, Frith, S. M, Gettleman, A, Hardiman, S. C, Kinnison, D. E, Lamarque, J.-F, Mancini, E, Marchand, M, Michou, M, Morgenstern, O, Nakamura, T, Olivie, D, Pawson, S, Pitari, G, Plummer, D. A, and Pyle, J. A

Subjects
Environment Pollution
Abstract

We demonstrate how observations of N2O and mean age in the tropical and midlatitude lower stratosphere (LS) can be used to identify realistic transport in models. The results are applied to 15 Chemistry Climate Models (CCMs) participating in the 2010 WMO assessment. Comparison of the observed and simulated N2O/mean age relationship identifies models with fast or slow circulations and reveals details of model ascent and tropical isolation. The use of this process-oriented N2O/mean age diagnostic identifies models with compensating transport deficiencies that produce fortuitous agreement with mean age. We compare the diagnosed model transport behavior with a model's ability to produce realistic LS O3 profiles in the tropics and midlatitudes. Models with the greatest tropical transport problems show the poorest agreement with observations. Models with the most realistic LS transport agree more closely with LS observations and each other. We incorporate the results of the chemistry evaluations in the SPARC CCMVal Report (2010) to explain the range of CCM predictions for the return-to-1980 dates for global (60 S-60 N) and Antarctic column ozone. Later (earlier) Antarctic return dates are generally correlated to higher (lower) vortex Cl(sub y) levels in the LS, and vortex Cl(sub y) is generally correlated with the model's circulation although model Cl(sub y) chemistry or Cl(sub y) conservation can have a significant effect. In both regions, models that have good LS transport produce a smaller range of predictions for the return-to-1980 ozone values. This study suggests that the current range of predicted return dates is unnecessarily large due to identifiable model transport deficiencies.

Published
2010

12. Multi-Model Assessment of the Factors Driving Stratospheric Ozone Evolution Over the 21st Century

Author

Oman, L. D, Plummer, D. A, Waugh, D. W, Austin, J, Scinocca, J, Douglass, A. R, Salawitch, R. J, Canty, T, Akiyoshi, H, Bekki, S, Braesicke, P, Butchart, N, Chipperfield, M. P, Cugnet, D, Dhomse, S, Eyring, V, Frith, S, Hardiman, S. C, Kinnison, D. E, Lamarque, J. F, Mancini, E, Marchand, M, Michou, M, Morgenstern, O, and Nakamura T

Subjects
Meteorology And Climatology
Abstract

The evolution of stratospheric ozone from 1960 to 2100 is examined in simulations from fourteen chemistry-climate models. There is general agreement among the models at the broadest levels, showing column ozone decreasing at all latitudes from 1960 to around 2000, then increasing at all latitudes over the first half of the 21st century, and latitudinal variations in the rate of increase and date of return to historical values. In the second half of the century, ozone is projected to continue increasing, level off or even decrease depending on the latitude, resulting in variable dates of return to historical values at latitudes where column ozone has declined below those levels. Separation into partial column above and below 20 hPa reveals that these latitudinal differences are almost completely due to differences in the lower stratosphere. At all latitudes, upper stratospheric ozone increases throughout the 21st century and returns to 1960 levels before the end of the century, although there is a spread among the models in dates that ozone returns to historical values. Using multiple linear regression, we find decreasing halogens and increasing greenhouse gases contribute almost equally to increases in the upper stratospheric ozone. In the tropical lower stratosphere an increase in tropical upwelling causes a steady decrease in ozone through the 21st century, and total column ozone does not return to 1960 levels in all models. In contrast, lower stratospheric and total column ozone in middle and high latitudes increases during the 21st century and returns to 1960 levels.

Published
2010

15. The nature of Arctic polar vortices in chemistry-climate models

Author

Mitchell, D. M., Charlton-Perez, A. J., Gray, L. J., Akiyoshi, H., Butchart, N., Hardiman, S. C., Morgenstern, O., Nakamura, T., Eugene Rozanov, Shibata, K., Smale, D., and Yamashita, Y.

Abstract

The structure of the Arctic stratospheric polar vortex in three chemistry-climate models (CCMs) taken from the CCMVal-2 intercomparison is examined using zonal mean and geometric-based methods. The geometric methods are employed by taking 2D moments of potential vorticity fields that are representative of the polar vortices in each of the models. This allows the vortex area, centroid location and ellipticity to be determined, as well as a measure of vortex filamentation. The first part of the study uses these diagnostics to examine how well the mean state, variability and extreme variability of the polar vortices are represented in CCMs compared to ERA-40 reanalysis data, and in particular for the UMUKCA-METO, NIWA-SOCOL and CCSR/NIES models. The second part of the study assesses how the vortices are predicted to change in terms of the frequency of sudden stratospheric warmings and their general structure over the period 1960-2100. In general, it is found that the vortices are climatologically too far poleward in the CCMs and produce too few large-scale filamentation events. Only a small increase is observed in the frequency of sudden stratospheric warming events from the mean of the CCMVal-2 models, but the distribution of extreme variability throughout the winter period is shown to change towards the end of the twentyfirst century. © 2012 Royal Meteorological Society and British Crown, the Met Office.

Published
2016

16. Possible impacts of a future grand solar minimum on climate: stratospheric and global circulation changes

Author

Maycock, A. C., Ineson, S., Gray, L. J., Scaife, A. A., Anstey, J. A., Lockwood, M., Butchart, N., Hardiman, S. C., Mitchell, D. M., and Osprey, S. M.

Subjects
Climate Change and Variability, Climatology, Solar Physics, Astrophysics, and Astronomy, stratosphere‐troposphere coupling, Climate Variability, Climate and Dynamics, Climate and Interannual Variability, Solar Irradiance, Solar and Stellar Variability, Solar Radiation and Cosmic Ray Effects, Oceanography: General, Climate Impact, Decadal Ocean Variability, grand solar minimum, Oceans, Atmospheric Processes, Solar Variability, Global Change, Regional Climate Change, Ionosphere, solar influences on climate, Natural Hazards, Research Articles, Oceanography: Physical, Research Article
Abstract

It has been suggested that the Sun may evolve into a period of lower activity over the 21st century. This study examines the potential climate impacts of the onset of an extreme “Maunder Minimum‐like” grand solar minimum using a comprehensive global climate model. Over the second half of the 21st century, the scenario assumes a decrease in total solar irradiance of 0.12% compared to a reference Representative Concentration Pathway 8.5 experiment. The decrease in solar irradiance cools the stratopause (∼1 hPa) in the annual and global mean by 1.2 K. The impact on global mean near‐surface temperature is small (∼−0.1 K), but larger changes in regional climate occur during the stratospheric dynamically active seasons. In Northern Hemisphere wintertime, there is a weakening of the stratospheric westerly jet by up to ∼3–4 m s−1, with the largest changes occurring in January–February. This is accompanied by a deepening of the Aleutian Low at the surface and an increase in blocking over Northern Europe and the North Pacific. There is also an equatorward shift in the Southern Hemisphere midlatitude eddy‐driven jet in austral spring. The occurrence of an amplified regional response during winter and spring suggests a contribution from a top‐down pathway for solar‐climate coupling; this is tested using an experiment in which ultraviolet (200–320 nm) radiation is decreased in isolation of other changes. The results show that a large decline in solar activity over the 21st century could have important impacts on the stratosphere and regional surface climate., Key Points A future decline in solar activity would not offset projected global warmingA future decline in solar activity could have larger regional effects in winterTop‐down mechanism contributes to Northern Hemisphere regional response

Published
2015

17. Northern winter climate change: assessment of uncertainty in CMIP5 projections related to stratosphere–troposphere coupling

Author

Manzini, E., Karpechko, A. Yu., Anstey, J., Baldwin, M. P., Black, R. X., Cagnazzo, C., Calvo, N., Charlton-Perez, A., Christiansen, B., Davini, Paolo, Gerber, E., Giorgetta, M., Gray, L., Hardiman, S. C., Lee, Y-Y, Marsh, D. R., McDaniel, B. A., Purich, A., Scaife, A. A., Shindell, D., Son, S-W, Watanabe, S., and Zappa, G.

Abstract

Future changes in the stratospheric circulation could have an important impact on Northern winter tropospheric climate change, given that sea level pressure (SLP) responds not only to tropospheric circulation variations but also to vertically coherent variations in troposphere-stratosphere circulation. Here we assess Northern winter stratospheric change and its potential to influence surface climate change in the Coupled Model Intercomparison Project – phase 5 (CMIP5) multi-model ensemble. In the stratosphere at high latitudes, an easterly change in zonally averaged zonal wind is found for the majority of the CMIP5 models, under the Representative Concentration Pathway 8.5 scenario. Comparable results are also found in the 1% CO2 increase per year projections, indicating that the stratospheric easterly change is common feature in future climate projections. This stratospheric wind change, however, shows a significant spread among the models. By using linear regression, we quantify the impact of tropical upper troposphere warming, polar amplification and the stratospheric wind change on SLP. We find that the inter-model spread in stratospheric wind change contributes substantially to the inter-model spread in Arctic SLP change. The role of the stratosphere in determining part of the spread in SLP change is supported by the fact that the SLP change lags the stratospheric zonally averaged wind change. Taken together, these findings provide further support for the importance of simulating the coupling between the stratosphere and the troposphere, to narrow the uncertainty in the future projection of tropospheric circulation changes.

Published
2014

18. Stratospheric Dynamics

Author

Butchart, N., Charlton-Perez, A., Cionni, I., Hardiman, S. C., and Krüger, Kirstin

Published
2010

19. Evaluation of Chemistry-Climate Models

Author

Eyring, V, Shepherd, T. G., Waugh, D. W., Morgenstern, O, Giorgetta, M. A., Shibata, K, Waugh, D, Akiyoshi, H, Austin, J, Baumgärtner, A, Bekki, S, Braesicke, P, Brühl, C, Chipperfield, M. P., Dameris, M, Frith, S, Garny, H, Gettelman, A, Hardiman, S. C., Hegglin, M, Jonsson, A, Kinnison, D, Lamarque, J. F., Mancini, E, Manzini, E, Michou, M, Nielsen, E, Pitari, Giovanni, Rozanov, E, Scinocca, J. F., Smale, D, Strahan, S, Toohey, M, and Tian, W.

Published
2010

20. Review of the formulation of present‐generation stratospheric chemistry‐climate models and associated external forcings

Author

Morgenstern, O., Giorgetta, M. A., Shibata, K., Eyring, V., Waugh, D. W., Shepherd, T. G., Akiyoshi, H., Austin, J., Baumgaertner, A. J. G., Bekki, S., Braesicke, P., Brühl, C., Chipperfield, M. P., Cugnet, D., Dameris, M., Dhomse, S., Frith, S. M., Garny, H., Gettelman, A., Hardiman, S. C., Hegglin, M. I., Jöckel, P., Kinnison, D. E., Lamarque, J. -F., Mancini, E., Manzini, E., Marchand, M., Michou, M., Nakamura, T., Nielsen, J. E., Olivié, D., Pitari, G., Plummer, D. A., Rozanov, E., Scinocca, J. F., Smale, D., Teyssèdre, H., Toohey, M., Tian, W., and Yamashita, Y.

Abstract

The goal of the Chemistry‐Climate Model Validation (CCMVal) activity is to improve understanding of chemistry‐climate models (CCMs) through process‐oriented evaluation and to provide reliable projections of stratospheric ozone and its impact on climate. An appreciation of the details of model formulations is essential for understanding how models respond to the changing external forcings of greenhouse gases and ozonedepleting substances, and hence for understanding the ozone and climate forecasts produced by the models participating in this activity. Here we introduce and review the models used for the second round (CCMVal‐2) of this intercomparison, regarding the implementation of chemical, transport, radiative, and dynamical processes in these models. In particular, we review the advantages and problems associated with approaches used to model processes of relevance to stratospheric dynamics and chemistry. Furthermore, we state the definitions of the reference simulations performed, and describe the forcing data used in these simulations. We identify some developments in chemistry‐climate modeling that make models more physically based or more comprehensive, including the introduction of an interactive ocean, online photolysis, troposphere‐stratosphere chemistry, and non‐orographic gravity‐wave deposition as linked to tropospheric convection. The\ud relatively new developments indicate that stratospheric CCM modeling is becoming more consistent with our physically based understanding of the atmosphere.

Published
2010

21. Chemistry‐climate model simulations of spring Antarctic ozone

Author

Austin, John, Struthers, H., Scinocca, J., Plummer, D. A., Akiyoshi, H., Baumgaertner, A. J. G., Bekki, S., Bodeker, G. E., Braesicke, P., Brühl, C., Butchart, N., Chipperfield, M. P., Cugnet, D., Dameris, M., Dhomse, S., Frith, S., Garny, H., Gettelman, A., Hardiman, S. C., Jöckel, P., Kinnison, D., Kubin, A., Lamarque, J. F., Langematz, U., Mancini, E., Marchland, M., Michou, M., Morgenstern, O., Nakamura, T., Nielsen, J. E., Pitari, G., Pyle, J., Rozanov, E., Shepherd, T. G., Shibata, K., Smale, D., Teyssèdre, H., and Yamashita, Y.

Abstract

Coupled chemistry‐climate model simulations covering the recent past and continuing throughout the 21st century have been completed with a range of different models. Common forcings are used for the halogen amounts and greenhouse gas concentrations, as expected under the Montreal Protocol (with amendments) and Intergovernmental Panel on Climate Change A1b Scenario. The simulations of the Antarctic ozone hole are compared using commonly used diagnostics: the minimum ozone, the maximum area of ozone below 220 DU, and the ozone mass deficit below 220 DU. Despite the fact that the processes responsible for ozone depletion are reasonably well understood, a wide range of results is obtained. Comparisons with observations indicate that one of the reasons for the model underprediction in ozone hole area is the tendency for models to underpredict, by up to 35%, the area of low temperatures responsible for polar stratospheric cloud formation. Models also typically have species gradients that are too weak at the edge of the polar vortex, suggesting that there is too much mixing of air across the vortex edge. Other models show a high bias in total column ozone which restricts the size of the ozone hole (defined by a 220 DU threshold). The results of those models which agree best with observations are examined in more detail. For several models the ozone hole does not disappear this century but a small ozone hole of up to three million square kilometers continues to occur in most springs even after 2070.

Published
2010

22. Northern winter climate change: Assessment of uncertainty in CMIP5 projections related to stratosphere-troposphere coupling

Author

Manzini, E., primary, Karpechko, A. Yu., additional, Anstey, J., additional, Baldwin, M. P., additional, Black, R. X., additional, Cagnazzo, C., additional, Calvo, N., additional, Charlton-Perez, A., additional, Christiansen, B., additional, Davini, Paolo, additional, Gerber, E., additional, Giorgetta, M., additional, Gray, L., additional, Hardiman, S. C., additional, Lee, Y.-Y., additional, Marsh, D. R., additional, McDaniel, B. A., additional, Purich, A., additional, Scaife, A. A., additional, Shindell, D., additional, Son, S.-W., additional, Watanabe, S., additional, and Zappa, G., additional

Published
2014
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24. The Met Office Unified Model Global Atmosphere 4.0 and JULES Global Land 4.0 configurations

Author

Walters, D. N., primary, Williams, K. D., additional, Boutle, I. A., additional, Bushell, A. C., additional, Edwards, J. M., additional, Field, P. R., additional, Lock, A. P., additional, Morcrette, C. J., additional, Stratton, R. A., additional, Wilkinson, J. M., additional, Willett, M. R., additional, Bellouin, N., additional, Bodas-Salcedo, A., additional, Brooks, M. E., additional, Copsey, D., additional, Earnshaw, P. D., additional, Hardiman, S. C., additional, Harris, C. M., additional, Levine, R. C., additional, MacLachlan, C., additional, Manners, J. C., additional, Martin, G. M., additional, Milton, S. F., additional, Palmer, M. D., additional, Roberts, M. J., additional, Rodríguez, J. M., additional, Tennant, W. J., additional, and Vidale, P. L., additional

Published
2014
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25. Multi-model climate and variability of the stratosphere

Author

Butchart, N., Charlton-Perez, A. J., Cionni, I., Hardiman, S. C., Haynes, P., Krüger, Kirstin, Butchart, N., Charlton-Perez, A. J., Cionni, I., Hardiman, S. C., Haynes, P., and Krüger, Kirstin

Abstract

The stratospheric climate and variability from simulations of sixteen chemistryclimate models is evaluated. On average the polar night jet is well reproduced though its variability is less well reproduced with a large spread between models. Polar temperature biases are less than 5 K except in the Southern Hemisphere (SH) lower stratosphere in spring. The accumulated area of low temperatures responsible for polar stratospheric cloud formation is accurately reproduced for the Antarctic but underestimated for the Arctic. The shape and position of the polar vortex is well simulated, as is the tropical upwelling in the lower stratosphere. There is a wide model spread in the frequency of major sudden stratospheric warnings (SSWs), late biases in the breakup of the SH vortex, and a weak annual cycle in the zonal wind in the tropical upper stratosphere. Quantitatively, “metrics” indicate a wide spread in model performance for most diagnostics with systematic biases in many, and poorer performance in the SH than in the Northern Hemisphere (NH). Correlations were found in the SH between errors in the final warming, polar temperatures, the leading mode of variability, and jet strength, and in the NH between errors in polar temperatures, frequency of major SSWs, and jet strength. Models with a stronger QBO have stronger tropical upwelling and a colder NH vortex. Both the qualitative and quantitative analysis indicate a number of common and long‐standing model problems, particularly related to the simulation of the SH and stratospheric variability.

Published
2011
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26. Multimodel assessment of the upper troposphere and lower stratosphere: Tropics and global trends

Author

Gettelman, A., Hegglin, M. I., Son, S.-W., Kim, Jung-Hyun, Fujiwara, M., Birner, T., Kremser, S., Rex, Markus, Anel, J. A., Akiyoshi, H., Austin, J., Bekki, S., Braesike, P., Brühl, C., Butchart, N., Chipperfield, M., Dameris, M., Dhomse, S., Garny, H., Hardiman, S. C., Jöckel, P., Kinnison, D. E., Lamarque, J. F., Mancini, E., Marchand, M., Michou, M., Morgenstern, O., Pawson, S., Pitari, G., Plummer, D., Pyle, J. A., Rozanov, E., Scinocca, J., Shepherd, T. G., Shibata, K., Smale, D., Teyssèdre, H., Tian, W., Gettelman, A., Hegglin, M. I., Son, S.-W., Kim, Jung-Hyun, Fujiwara, M., Birner, T., Kremser, S., Rex, Markus, Anel, J. A., Akiyoshi, H., Austin, J., Bekki, S., Braesike, P., Brühl, C., Butchart, N., Chipperfield, M., Dameris, M., Dhomse, S., Garny, H., Hardiman, S. C., Jöckel, P., Kinnison, D. E., Lamarque, J. F., Mancini, E., Marchand, M., Michou, M., Morgenstern, O., Pawson, S., Pitari, G., Plummer, D., Pyle, J. A., Rozanov, E., Scinocca, J., Shepherd, T. G., Shibata, K., Smale, D., Teyssèdre, H., and Tian, W.

Published
2010

27. Supplementary material to "The Met Office Unified Model Global Atmosphere 4.0 and JULES Global Land 4.0 configurations"

Author

Walters, D. N., primary, Williams, K. D., additional, Boutle, I. A., additional, Bushell, A. C., additional, Edwards, J. M., additional, Field, P. R., additional, Lock, A. P., additional, Morcrette, C. J., additional, Stratton, R. A., additional, Wilkinson, J. M., additional, Willett, M. R., additional, Bellouin, N., additional, Bodas-Salcedo, A., additional, Brooks, M. E., additional, Copsey, D., additional, Earnshaw, P. D., additional, Hardiman, S. C., additional, Harris, C. M., additional, Levine, R. C., additional, MacLachlan, C., additional, Manners, J. C., additional, Martin, G. M., additional, Milton, S. F., additional, Palmer, M. D., additional, Roberts, M. J., additional, Rodríguez, J. M., additional, Tennant, W. J., additional, and Vidale, P. L., additional

Published
2013
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28. The Met Office Unified Model Global Atmosphere 4.0 and JULES Global Land 4.0 configurations

Author

Walters, D. N., primary, Williams, K. D., additional, Boutle, I. A., additional, Bushell, A. C., additional, Edwards, J. M., additional, Field, P. R., additional, Lock, A. P., additional, Morcrette, C. J., additional, Stratton, R. A., additional, Wilkinson, J. M., additional, Willett, M. R., additional, Bellouin, N., additional, Bodas-Salcedo, A., additional, Brooks, M. E., additional, Copsey, D., additional, Earnshaw, P. D., additional, Hardiman, S. C., additional, Harris, C. M., additional, Levine, R. C., additional, MacLachlan, C., additional, Manners, J. C., additional, Martin, G. M., additional, Milton, S. F., additional, Palmer, M. D., additional, Roberts, M. J., additional, Rodríguez, J. M., additional, Tennant, W. J., additional, and Vidale, P. L., additional

Published
2013
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31. The nature of Arctic polar vortices in chemistry–climate models

Author

Mitchell, D. M., primary, Charlton‐Perez, A. J., additional, Gray, L. J., additional, Akiyoshi, H., additional, Butchart, N., additional, Hardiman, S. C., additional, Morgenstern, O., additional, Nakamura, T., additional, Rozanov, E., additional, Shibata, K., additional, Smale, D., additional, and Yamashita, Y., additional

Published
2012
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32. Using transport diagnostics to understand chemistry climate model ozone simulations

Author

Strahan, S. E., primary, Douglass, A. R., additional, Stolarski, R. S., additional, Akiyoshi, H., additional, Bekki, S., additional, Braesicke, P., additional, Butchart, N., additional, Chipperfield, M. P., additional, Cugnet, D., additional, Dhomse, S., additional, Frith, S. M., additional, Gettelman, A., additional, Hardiman, S. C., additional, Kinnison, D. E., additional, Lamarque, J.-F., additional, Mancini, E., additional, Marchand, M., additional, Michou, M., additional, Morgenstern, O., additional, Nakamura, T., additional, Olivié, D., additional, Pawson, S., additional, Pitari, G., additional, Plummer, D. A., additional, Pyle, J. A., additional, Scinocca, J. F., additional, Shepherd, T. G., additional, Shibata, K., additional, Smale, D., additional, Teyssèdre, H., additional, Tian, W., additional, and Yamashita, Y., additional

Published
2011
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33. The HadGEM2-ES implementation of CMIP5 centennial simulations

Author

Jones, C. D., primary, Hughes, J. K., additional, Bellouin, N., additional, Hardiman, S. C., additional, Jones, G. S., additional, Knight, J., additional, Liddicoat, S., additional, O'Connor, F. M., additional, Andres, R. J., additional, Bell, C., additional, Boo, K.-O., additional, Bozzo, A., additional, Butchart, N., additional, Cadule, P., additional, Corbin, K. D., additional, Doutriaux-Boucher, M., additional, Friedlingstein, P., additional, Gornall, J., additional, Gray, L., additional, Halloran, P. R., additional, Hurtt, G., additional, Ingram, W. J., additional, Lamarque, J.-F., additional, Law, R. M., additional, Meinshausen, M., additional, Osprey, S., additional, Palin, E. J., additional, Parsons Chini, L., additional, Raddatz, T., additional, Sanderson, M. G., additional, Sellar, A. A., additional, Schurer, A., additional, Valdes, P., additional, Wood, N., additional, Woodward, S., additional, Yoshioka, M., additional, and Zerroukat, M., additional

Published
2011
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34. Multimodel climate and variability of the stratosphere

Author

Butchart, N., primary, Charlton-Perez, A. J., additional, Cionni, I., additional, Hardiman, S. C., additional, Haynes, P. H., additional, Krüger, K., additional, Kushner, P. J., additional, Newman, P. A., additional, Osprey, S. M., additional, Perlwitz, J., additional, Sigmond, M., additional, Wang, L., additional, Akiyoshi, H., additional, Austin, J., additional, Bekki, S., additional, Baumgaertner, A., additional, Braesicke, P., additional, Brühl, C., additional, Chipperfield, M., additional, Dameris, M., additional, Dhomse, S., additional, Eyring, V., additional, Garcia, R., additional, Garny, H., additional, Jöckel, P., additional, Lamarque, J.-F., additional, Marchand, M., additional, Michou, M., additional, Morgenstern, O., additional, Nakamura, T., additional, Pawson, S., additional, Plummer, D., additional, Pyle, J., additional, Rozanov, E., additional, Scinocca, J., additional, Shepherd, T. G., additional, Shibata, K., additional, Smale, D., additional, Teyssèdre, H., additional, Tian, W., additional, Waugh, D., additional, and Yamashita, Y., additional

Published
2011
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35. Multimodel assessment of the upper troposphere and lower stratosphere: Extratropics

Author

Hegglin, M. I., primary, Gettelman, A., additional, Hoor, P., additional, Krichevsky, R., additional, Manney, G. L., additional, Pan, L. L., additional, Son, S.-W., additional, Stiller, G., additional, Tilmes, S., additional, Walker, K. A., additional, Eyring, V., additional, Shepherd, T. G., additional, Waugh, D., additional, Akiyoshi, H., additional, Añel, J. A., additional, Austin, J., additional, Baumgaertner, A., additional, Bekki, S., additional, Braesicke, P., additional, Brühl, C., additional, Butchart, N., additional, Chipperfield, M., additional, Dameris, M., additional, Dhomse, S., additional, Frith, S., additional, Garny, H., additional, Hardiman, S. C., additional, Jöckel, P., additional, Kinnison, D. E., additional, Lamarque, J. F., additional, Mancini, E., additional, Michou, M., additional, Morgenstern, O., additional, Nakamura, T., additional, Olivié, D., additional, Pawson, S., additional, Pitari, G., additional, Plummer, D. A., additional, Pyle, J. A., additional, Rozanov, E., additional, Scinocca, J. F., additional, Shibata, K., additional, Smale, D., additional, Teyssèdre, H., additional, Tian, W., additional, and Yamashita, Y., additional

Published
2010
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36. Multimodel assessment of the upper troposphere and lower stratosphere: Tropics and global trends

Author

Gettelman, A., primary, Hegglin, M. I., additional, Son, S.-W., additional, Kim, J., additional, Fujiwara, M., additional, Birner, T., additional, Kremser, S., additional, Rex, M., additional, Añel, J. A., additional, Akiyoshi, H., additional, Austin, J., additional, Bekki, S., additional, Braesike, P., additional, Brühl, C., additional, Butchart, N., additional, Chipperfield, M., additional, Dameris, M., additional, Dhomse, S., additional, Garny, H., additional, Hardiman, S. C., additional, Jöckel, P., additional, Kinnison, D. E., additional, Lamarque, J. F., additional, Mancini, E., additional, Marchand, M., additional, Michou, M., additional, Morgenstern, O., additional, Pawson, S., additional, Pitari, G., additional, Plummer, D., additional, Pyle, J. A., additional, Rozanov, E., additional, Scinocca, J., additional, Shepherd, T. G., additional, Shibata, K., additional, Smale, D., additional, Teyssèdre, H., additional, and Tian, W., additional

Published
2010
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37. Impact of stratospheric ozone on Southern Hemisphere circulation change: A multimodel assessment

Author

Son, S.-W., primary, Gerber, E. P., additional, Perlwitz, J., additional, Polvani, L. M., additional, Gillett, N. P., additional, Seo, K.-H., additional, Eyring, V., additional, Shepherd, T. G., additional, Waugh, D., additional, Akiyoshi, H., additional, Austin, J., additional, Baumgaertner, A., additional, Bekki, S., additional, Braesicke, P., additional, Brühl, C., additional, Butchart, N., additional, Chipperfield, M. P., additional, Cugnet, D., additional, Dameris, M., additional, Dhomse, S., additional, Frith, S., additional, Garny, H., additional, Garcia, R., additional, Hardiman, S. C., additional, Jöckel, P., additional, Lamarque, J. F., additional, Mancini, E., additional, Marchand, M., additional, Michou, M., additional, Nakamura, T., additional, Morgenstern, O., additional, Pitari, G., additional, Plummer, D. A., additional, Pyle, J., additional, Rozanov, E., additional, Scinocca, J. F., additional, Shibata, K., additional, Smale, D., additional, Teyssèdre, H., additional, Tian, W., additional, and Yamashita, Y., additional

Published
2010
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38. Multi-model assessment of stratospheric ozone return dates and ozone recovery in CCMVal-2 models

Author

Eyring, V., primary, Cionni, I., additional, Bodeker, G. E., additional, Charlton-Perez, A. J., additional, Kinnison, D. E., additional, Scinocca, J. F., additional, Waugh, D. W., additional, Akiyoshi, H., additional, Bekki, S., additional, Chipperfield, M. P., additional, Dameris, M., additional, Dhomse, S., additional, Frith, S. M., additional, Garny, H., additional, Gettelman, A., additional, Kubin, A., additional, Langematz, U., additional, Mancini, E., additional, Marchand, M., additional, Nakamura, T., additional, Oman, L. D., additional, Pawson, S., additional, Pitari, G., additional, Plummer, D. A., additional, Rozanov, E., additional, Shepherd, T. G., additional, Shibata, K., additional, Tian, W., additional, Braesicke, P., additional, Hardiman, S. C., additional, Lamarque, J. F., additional, Morgenstern, O., additional, Pyle, J. A., additional, Smale, D., additional, and Yamashita, Y., additional

Published
2010
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40. Supplementary material to "Multi-model assessment of stratospheric ozone return dates and ozone recovery in CCMVal-2 models"

Author

Eyring, V., primary, Cionni, I., additional, Bodeker, G. E., additional, Charlton-Perez, A. J., additional, Kinnison, D. E., additional, Scinocca, J. F., additional, Waugh, D. W., additional, Akiyoshi, H., additional, Bekki, S., additional, Chipperfield, M. P., additional, Dameris, M., additional, Dhomse, S., additional, Frith, S. M., additional, Garny, H., additional, Gettelman, A., additional, Kubin, A., additional, Langematz, U., additional, Mancini, E., additional, Marchand, M., additional, Nakamura, T., additional, Oman, L. D., additional, Pawson, S., additional, Pitari, G., additional, Plummer, D. A., additional, Rozanov, E., additional, Shepherd, T. G., additional, Shibata, K., additional, Tian, W., additional, Braesicke, P., additional, Hardiman, S. C., additional, Lamarque, J. F., additional, Morgenstern, O., additional, Pyle, J. A., additional, Smale, D., additional, and Yamashita, Y., additional

Published
2010
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42. Decline and recovery of total column ozone using a multimodel time series analysis

Author

Austin, John, primary, Scinocca, J., additional, Plummer, D., additional, Oman, L., additional, Waugh, D., additional, Akiyoshi, H., additional, Bekki, S., additional, Braesicke, P., additional, Butchart, N., additional, Chipperfield, M., additional, Cugnet, D., additional, Dameris, M., additional, Dhomse, S., additional, Eyring, V., additional, Frith, S., additional, Garcia, R. R., additional, Garny, H., additional, Gettelman, A., additional, Hardiman, S. C., additional, Kinnison, D., additional, Lamarque, J. F., additional, Mancini, E., additional, Marchand, M., additional, Michou, M., additional, Morgenstern, O., additional, Nakamura, T., additional, Pawson, S., additional, Pitari, G., additional, Pyle, J., additional, Rozanov, E., additional, Shepherd, T. G., additional, Shibata, K., additional, Teyssèdre, H., additional, Wilson, R. J., additional, and Yamashita, Y., additional

Published
2010
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43. Anthropogenic forcing of the Northern Annular Mode in CCMVal‐2 models

Author

Morgenstern, O., primary, Akiyoshi, H., additional, Bekki, S., additional, Braesicke, P., additional, Butchart, N., additional, Chipperfield, M. P., additional, Cugnet, D., additional, Deushi, M., additional, Dhomse, S. S., additional, Garcia, R. R., additional, Gettelman, A., additional, Gillett, N. P., additional, Hardiman, S. C., additional, Jumelet, J., additional, Kinnison, D. E., additional, Lamarque, J.‐F., additional, Lott, F., additional, Marchand, M., additional, Michou, M., additional, Nakamura, T., additional, Olivié, D., additional, Peter, T., additional, Plummer, D., additional, Pyle, J. A., additional, Rozanov, E., additional, Saint‐Martin, D., additional, Scinocca, J. F., additional, Shibata, K., additional, Sigmond, M., additional, Smale, D., additional, Teyssèdre, H., additional, Tian, W., additional, Voldoire, A., additional, and Yamashita, Y., additional

Published
2010
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44. The HadGEM2 family of Met Office Unified Model climate configurations.

Author

Martin, G. M., Bellouin, N., Collins, W. J., Culverwell, I. D., Halloran, P. R., Hardiman, S. C., Hinton, T. J., Jones, C. D., McDonald, R. E., McLaren, A. J., O'Connor, F. M., Roberts, M. J., Rodriguez, J. M., Woodward, S., Best, M. J., Brooks, M. E., Brown, A. R., Butchart, N., Dearden, C., and Derbyshire, S. H.

Subjects
METEOROLOGICAL research, ATMOSPHERIC research, CLIMATOLOGY, ENVIRONMENTAL sciences, EARTH sciences
Abstract

The article presents a study which examines the HadGEM2 family of climate configurations of the Met Office Unified Model (MetUM). It is inferred that the HadGEM 2 family of climate configurations includes ocean-atmosphere and Earth-System (ES) components. The errors addressed by the HadGEM2 family are highlighted which include poor variability, tropical sea surface temperature and Northern Hemisphere continental temperature biases.

Published
2011
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45. Impact of Stratospheric Ozone on Southern Hemisphere Circulation Change: A Multimodel Assessment

Author

Son, S.-W., Gerber, E. P., Perlwitz, J., Polvani, Lorenzo M., Gillett, N. P., Seo, K.-H., Eyring, V., Shepherd, T. G., Waugh, D., Akiyoshi, H., Austin, J., Baumgaertner, A., Bekki, S., Braesicke, P., Brühl, C., Butchart, N., Chipperfield, M. P., Cugnet, D., Dameris, M., Frith, S., Dhomse, S., Garny, H., Garcia, R., Hardiman, S. C., Jöckel, P., Lamarque, J. F., Mancini, E., Marchand, M., Nakamura, T., Michou, M., Morgenstern, O., Pitari, G., Plummer, D. A., Pyle, J., Rozanov, E., Scinocca, J. F., Shibata, K., Smale, D., Teyssèdre, H., Tian, W., and Yamashita, Y.

Subjects
Meteorology, 13. Climate action, Atmosphere, Atmosphere, Upper
Abstract

The impact of stratospheric ozone on the tropospheric general circulation of the Southern Hemisphere (SH) is examined with a set of chemistry-climate models participating in the Stratospheric Processes and their Role in Climate (SPARC)/Chemistry-Climate Model Validation project phase 2 (CCMVal-2). Model integrations of both the past and future climates reveal the crucial role of stratospheric ozone in driving SH circulation change: stronger ozone depletion in late spring generally leads to greater poleward displacement and intensification of the tropospheric midlatitude jet, and greater expansion of the SH Hadley cell in the summer. These circulation changes are systematic as poleward displacement of the jet is typically accompanied by intensification of the jet and expansion of the Hadley cell. Overall results are compared with coupled models participating in the Intergovernmental Panel on Climate Change Fourth Assessment Report (IPCC AR4), and possible mechanisms are discussed. While the tropospheric circulation response appears quasi-linearly related to stratospheric ozone changes, the quantitative response to a given forcing varies considerably from one model to another. This scatter partly results from differences in model climatology. It is shown that poleward intensification of the westerly jet is generally stronger in models whose climatological jet is biased toward lower latitudes. This result is discussed in the context of quasi-geostrophic zonal mean dynamics.

46. Possible impacts of a future grand solar minimum on climate: Stratospheric and global circulation changes.

Author

Maycock AC, Ineson S, Gray LJ, Scaife AA, Anstey JA, Lockwood M, Butchart N, Hardiman SC, Mitchell DM, and Osprey SM

Abstract

A future decline in solar activity would not offset projected global warmingA future decline in solar activity could have larger regional effects in winterTop-down mechanism contributes to Northern Hemisphere regional response.

Published
2015
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