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Major explosive volcanic eruptions were important triggers of abrupt climate changes during the Holocene and crucial sources of Hg to the atmosphere, yet there remains limited understanding regarding the long‐range transportation of this volcanic Hg and its imprint in natural archives. Here, we present a reconstruction of Holocene global volcanism based on the anomalies in Hg concentrations, accumulation fluxes, and Hg/C ratios in three high‐resolution peat profiles spanning Eurasia. Our reconstruction reveals that the two Tibetan peat profiles recorded 33 major explosive volcanic eruptions (with 11 eruptions being synchronously detected), which correspond with a French Pyrenees peat record and sulfate anomalies in polar ice cores. Additionally, the major explosive volcanic eruptions recorded in the TP peat profiles coincided with abrupt decreases in solar irradiance during the Holocene, suggesting these eruptions might have had a greater global climate impact. Our results suggest the atmospheric transport of volcanic Hg within the Northern Hemisphere and underscore the significant role played by major explosive volcanic eruptions in precipitating abrupt global climate and environmental changes during the Holocene. This study has implications for deciphering the configuration of volcanic eruption seasons, locations, and magnitudes during the Holocene and aligning the chronology of peat deposits with ice cores. Plain Language Summary: Major explosive volcanic eruptions, one of the principal geogenic sources of Hg to the atmosphere, are widely acknowledged as significant drivers of abrupt global environmental and climate changes during the Holocene. While the magnitudes and timing of these eruptions have been well documented in ice core records, the long‐range transportation of the volcanic materials (such as Hg and SO2) and their terrestrial dispersion remain largely unknown. In this study, we present a reconstruction of Holocene global volcanism based on the anomalies in Hg concentrations, accumulation fluxes, and Hg/C ratios in three high‐resolution peat profiles, with two collected from the Tibetan Plateau and one from the French Pyrenees. Our reconstruction reveals that the Tibetan peat profiles recorded 33 major volcanic eruptions, which correspond with a French peat record and the sulfate anomalies in polar ice cores. Additionally, we demonstrate that certain major explosive volcanic eruptions likely triggered several abrupt decreases in solar irradiance during the Holocene. Our findings suggest the convective atmospheric transport of volcanic Hg within the Northern Hemisphere extratropical region and underscore the significant role played by major explosive volcanic eruptions in precipitating abrupt global climate and environmental changes during the Holocene. Key Points: Eleven major explosive volcanic eruptions during the Holocene were synchronously recorded in two peat profiles in the Tibetan PlateauThe recorded major explosive volcanic eruptions coincide with nine abrupt decreases in solar irradiance during the HoloceneThe Hg anomalies in peat profiles have the potential to be chronology markers that were linked with volcanic eruptions [ABSTRACT FROM AUTHOR]

Studies of the Last Interglacial (ca. 129 to 116 ka BP) provide an opportunity to study the impact of high‐latitude warm temperatures on the Earth system. To build an accurate spatio‐temporal picture of climate and environmental variability during the Last Interglacial, building robust chronologies, through which the patchwork of terrestrial, marine, and ice core archives can be correlated, is paramount. In this review, we briefly evaluate the most common approaches used to date climate and environmental archives from the Last Interglacial, as well as the chronostratigraphic tools available for direct correlation between sequences, with a focus on terrestrial archives. We then present a case study on the use of pollen biostratigraphy for correlating sequences in NW Europe, highlighting its strength as a local correlation tool, and the challenges this approach presents in comparing sequences to global records of climate and environmental change. A move towards consistently dated sequences will improve our understanding of environmental responses to Last Interglacial climate variability across different elements of the global climate system and the rates at which different elements of the climate system respond to changes in global temperatures. [ABSTRACT FROM AUTHOR]

The Deliblato (Banat) Sand Sea, which is one of the largest areas of аeolian sand in Europe, is located near the Iron Gate, which marks the crossing of the Danube River through the biggest gorge of this river. Here, Danubian alluvium has served as the sand source for the Banat Sand Sea, which was formed primarily through southeasterly (Košava) winds. Utilizing a multi-proxy approach, the objective of this study is to gain a better understanding of the environmental dynamics of the Banat Sand Sea. To achieve this goal, we conducted an analysis of an archive representing an approximately 20-m-thick dune formation on the northern edge of this dune field. Using optically stimulated luminescence (OSL) dating, we calculated aeolian sedimentation rates and dune ages. Sand was deposited here approximately between 17 ka and 13 ka. Magnetic susceptibility, grain size, and colorimetric analyses were interpreted in terms of local paleoenvironmental conditions. Calculated sedimentation rates (SR) indicate intensive aeolian deposition during the study period that range from 483 cm/ka to 502 cm/ka. We compared our data with regional and other European archives, as well as with climatic variations recorded in the Greenland ice core North Greenland Ice Core Project (NGRIP). [ABSTRACT FROM AUTHOR]

We analyze the temperature time series of the EPICA Dome C ice cores in Antarctica and of the Greenland project, Summit, with durations of 800 000 and 248 000 years, respectively, with a recent mathematical tool defined through the Fourier phases of the series, known as the J -index. This data driven index can differentiate between purely random dynamics and dynamics with a deterministic component. It is sensitive to nonlinear components and robust to the presence of noise. Our J -index data analysis shows that both Greenland and Antarctica climatic fluctuations possess deterministic traits and suggests the presence of an underlying nonlinear dynamics. Furthermore, in both regions, it reveals the simultaneous occurrence of an important global event known as the "Pelukian transgression." For Antarctica, it also detects the marine isotopic stage 11. Additionally, our calculation of the time series Hurst exponents and our detrended fluctuation analysis show the presence of long-range persistent correlations for Antarctica and anti-persistent correlations for Greenland. For the latter case, our fractal dimension determinations are indicative of a more complex climatic dynamics in Greenland with respect to Antarctica. Our results are encouraging for further development of climate variability deterministic models for these regions. [ABSTRACT FROM AUTHOR]

The isotopic signature (δ18О, δ2Н, d-excess) of the glacier ice in Ushkovskii volcano (Kamchatka Peninsula) was studied. A new shallow ice core was obtained in 2022 in the Gorshkov crater. The 14 m long ice core was dated by counting the annual layers, which were also compared with known eruptions in recent years. The upper 14 m of the glacier were formed over the last 16 years (from 2006 to 2022). The values of δ18О vary from −16 to −24‰, and the values of δ2Н, from −110.5 to −177.7‰, while the mean values are −20.5 and −150.2‰, respectively. The d-excess values vary with depth from 8.7 to 21.3‰ at a mean value of 13.7‰. For winter horizons at low values of δ18О and δ2Н, an increase in d-excess is noted. Such features are associated with the origin of moisture brought to Kamchatka. The source of moisture is the Pacific Ocean, the Sea of Okhotsk, and the Sea of Japan, for which there are pronounced differences in the conditions of moisture evaporation between summer and winter. The trends of increases in the δ18О and δ2Н values from 2006 to 2022 are accompanied by a decrease in the deuterium excess, indicating an increase in summer precipitation. However, in addition to changes in the seasonal proportions of precipitation, the d-excess values of ice may reflect climatic changes in the source of moisture. [ABSTRACT FROM AUTHOR]

Palaeoclimate time series, reflecting the state of Earth's climate in the distant past, occasionally display very large and rapid shifts showing abrupt climate variability. The identification and characterisation of these abrupt transitions in palaeoclimate records is of particular interest as this allows for understanding of millennial climate variability and the identification of potential tipping points in the context of current climate change. Methods that are able to characterise these events in an objective and automatic way, in a single time series, or across two proxy records are therefore of particular interest. In our study the matrix profile approach is used to describe Dansgaard–Oeschger (DO) events, abrupt warmings detected in the Greenland ice core, and Northern Hemisphere marine and continental records. The results indicate that canonical events DO-19 and DO-20, occurring at around 72 and 76 ka, are the most similar events over the past 110 000 years. These transitions are characterised by matching transitions corresponding to events DO-1, DO-8, and DO-12. They are abrupt, resulting in a rapid shift to warmer conditions, followed by a gradual return to cold conditions. The joint analysis of the δ18 O and Ca 2+ time series indicates that the transition corresponding to the DO-19 event is the most similar event across the two time series. [ABSTRACT FROM AUTHOR]

Today, volcanic sulfur emissions into the atmosphere are measured spectroscopically from the ground, air and space. For eruptions prior to the satellite era, two main sulfur proxies are used, the rock and ice core records, as illustrated by Peccia et al. (2023, https://doi.org/10.1029/2023gl103334). The first approach is based on calculations of the sulfur content of the magma, while the second uses traces of sulfur deposited in ice. Both approaches have their limitations. For glaciochemistry, the volcano responsible for a sulfur anomaly is often unknown and the atmospheric pathway by which the sulfur reached the ice uncertain. The petrologic method relies, too, on uncertain estimates of eruption size and a number of geochemical assumptions that are hard to verify. A deeper knowledge of processes occurring both within magma bodies prior to eruption, and within volcanic plumes in the atmosphere is needed to further our understanding of the impacts of volcanism on climate. Plain Language Summary: Volcanic emissions of sulfur gases during large eruptions can change the global climate. Today, advanced spectroscopic tools allow us to measure sulfur from the ground, air and space. But to understand the impacts of volcanic activity on climate back through history we need to estimate volcanic sulfur releases in other ways. Clues can be found in the pumice deposits found around a volcano and, perhaps more surprisingly, in the ice caps of the polar regions, which receive the eventual fallout from large eruptions. Both approaches have limitations that are addressed in a recent work by Peccia et al. (2023, https://doi.org/10.1029/2023gl103334) and that are at the focus of our commentary. Key Points: The impact of volcanic activity on climate remains difficult to quantify for eruptions prior to the instrumental eraThe petrological and glaciochemical methods each provide answers, but are still fraught with large uncertaintiesWe need to further our understanding of the physicochemical processes occurring both within magma reservoirs and volcanic plumes [ABSTRACT FROM AUTHOR]

Insects are vital arthropods that significantly impact various ecosystems. Their successful colonization of diverse habitats spanning from cold to warm environments is made possible by numerous adaptations shaped by environmental selection. This comprehensive review delves into the spectrum of physiological adaptations exhibited by insects to thrive in diverse environments, with a particular emphasis on the connection between these adaptations and the challenges posed by cold temperatures. Focusing on both long-term and short-term strategies, the review highlights the key protective mechanisms that insects employ to cope and thrive in cold temperatures. To withstand these constraints, insects have developed four main strategies: freeze tolerance, freeze avoidance, cryoprotective dehydration, and vitrification. These adaptive responses involve crucial physiological and biochemical changes that enable insects to withstand low temperatures. Specifically, insects exhibit cold tolerance through a range of molecular adaptive strategies, which encompass alterations in the expression of specific target genes, the synthesis of ice core formers, and the production of polyol cryoprotectants. Despite these remarkable results, there is still a lack of in-depth knowledge about the major factors contributing to successful overwintering of insects and their ability to withstand extremely low temperatures. To address these gaps, technological advances and genome sequencing of model organisms are critical to uncover the molecular mechanisms in insect responses to low temperatures. The knowledge gained from these advances provides valuable information about insect cold tolerance strategies and paves the way for a better understanding of their ecological importance and potential applications in conservation and ecological management. [ABSTRACT FROM AUTHOR]

Seasonal temperature reconstructions from ice cores are missing over glacial–interglacial timescales, preventing a good understanding of the driving factors of Antarctic past climate changes. Here the total air content (TAC) record from the Antarctic EPICA Dome C (EDC) ice core is analyzed over the last 440 ka (thousand years). While the water isotopic record, a tracer for annual mean surface temperature, exhibits a dominant ∼100 kyr cyclicity, the TAC record is associated with a dominant ∼40 kyr cyclicity. Our results show that the TAC record is anti-correlated with the mean insolation over the local astronomical summer half-year. They also show for the first time that it is highly anti-correlated with local summer temperature simulated with an Earth system model of intermediate complexity. We propose that (1) the local summer insolation controls the local summer temperature; (2) the latter, through the development of temperature gradients at the near-surface of the ice sheet (<2 m), is affecting the surface snow structure; and (3) those snow structure changes propagating down to the bottom of the firn through densification are eventually controlling the pore volume at the bubble close-off and consequently the TAC. Hence, our results suggest that the EDC TAC record could be used as a proxy for local summer temperature changes. Also, our new simulations show that the mean insolation over the local astronomical summer half-year is the primary driver of Antarctic summer surface temperature variations, while changes in atmospheric greenhouse gas (GHG) concentrations and Northern Hemisphere (NH) ice sheet configurations play a more important role in Antarctic annual surface temperature changes. [ABSTRACT FROM AUTHOR]

The Intergovernmental Panel on Climate Change (IPCC) concluded that the latest decade was warmer than any multi-century period over the past 125,000 years. This statement rests on a comparison of modern instrumental measurements against the course of past temperatures reconstructed from natural proxy archives, such as lake and marine sediments, and peat bogs. Here, we evaluate this comparison with a focus on the hundreds of proxy records developed by paleoclimatologists across the globe to reconstruct climate variability over the Holocene (12,000 years) and preceded by the Last Glacial Period (125,000 years). Although the existing proxy data provide a unique opportunity to reconstruct low-frequency climate variability on centennial timescales, they lack temporal resolution and dating precision for contextualizing the most recent temperature extremes. While the IPCC's conclusion on the uniqueness of latest-decade warming is thus not supported by comparison with these smoothed paleotemperatures, it is still likely correct as ice core-derived forcing timeseries show that greenhouse gases were not elevated during any pre-instrumental period of the Holocene. [ABSTRACT FROM AUTHOR]

Millennial-scale climate variations during the last glacial period, such as Dansgaard–Oeschger (DO) cycles and Heinrich events, have been extensively studied using ice core and marine proxy records. However, there is a limited understanding of the magnitude of these temperature fluctuations in continental regions, and questions remain about the seasonal signal of these climate events. This study presents a 60 000-year-long temperature reconstruction based on branched glycerol dialkyl glycerol tetraethers (brGDGTs) extracted from lake sediments from the Eifel Volcanic Field, Germany. brGDGTs are bacterial membrane-spanning lipids that are known to have a strong relationship with temperature, making them suitable for temperature reconstructions. We test several temperature calibration models on modern samples taken from soils and multiple maar lakes. We find a negative bias in brGDGT-based temperature estimates associated with water depth and anoxic conditions that can be corrected for by accounting for a brGDGT isomer that is only produced in anoxic conditions. The corrected temperature reconstruction correlates with proxy and climate model estimates of temperature spanning the same time period, validating the calibration approach we selected. However, millennial-scale variability is significantly dampened in the brGDGT record, and in contrast to other Northern Hemisphere climate records, during several Heinrich stadials, temperatures actually increase. We demonstrate that these apparent discrepancies can be explained by the unique seasonal response of the brGDGT paleothermometer to temperatures of months above freezing (TMAF). Our data support the view that warm-season temperatures in Europe varied minimally during the last glacial period and that abrupt millennial-scale events were defined by colder, longer winters. Our continuous high-resolution temperature reconstruction provides important information about the magnitude of seasonal climate variability during the last glacial period that can be used to test climate models and inform studies of paleoecological change. [ABSTRACT FROM AUTHOR]

Given growing concerns about climate tipping points and their risks, it is important to investigate the capability of identifying robust precursor signals for the associated transitions. In general, the variance and short-lag autocorrelations of the fluctuations increase in a stochastically forced system approaching a critical or bifurcation-induced transition, making them theoretically suitable indicators to warn of such transitions. Paleoclimate records provide useful test beds if such a warning of a forthcoming transition could work in practice. The Dansgaard–Oeschger (DO) events are characterized by millennial-scale abrupt climate changes during the glacial period, manifesting most clearly as abrupt temperature shifts in the North Atlantic region. Some previous studies have found such statistical precursor signals for the DO warming transitions. On the other hand, statistical precursor signals for the abrupt DO cooling transitions have not been identified. Analyzing Greenland ice core records, we find robust and statistically significant precursor signals of DO cooling transitions in most of the interstadials longer than roughly 1500 years but not in the shorter interstadials. The origin of the statistical precursor signals is mainly related to so-called rebound events, humps in the temperature observed at the end of interstadial, some decades to centuries prior to the actual transition. We discuss several dynamical mechanisms that give rise to such rebound events and statistical precursor signals. [ABSTRACT FROM AUTHOR]

Three hundred forty‐one radiocarbon dates from the Groningen radiocarbon database are compiled in this study. They show for the first time that organic sediment samples from the eastern Netherlands and mammal bones from Doggerland reflect shifts in the presence and the density of vegetation (food for herbivores) and mammal biomass during the last ice age (Weichselian Stage, ~119–14.7 ka cal bp). Comparison with oxygen isotope curves of Greenland ice cores and geomorphological data shows that cold climate, in particular during the younger part of the Weichselian Middle Pleniglacial and during the Late Pleniglacial, and related scarcity or even absence of vegetation, were limiting factors for the carrying capacity of the landscape and thus for the population density of large herbivores during the period covered by 14C dating (last ca. 55 000 years). A 'fossil gap' during the Late Pleniglacial lasted ca. 13 000 years from ca. 28 to 15 ka cal bp. Previous research from the nearby Eifel region in Germany shows that environmental conditions were less extreme ('refugium conditions') than in the Netherlands, taking into account the continuous presence of spores of coprophilous fungi in the Eifel, indicating uninterrupted food supply for herbivores. [ABSTRACT FROM AUTHOR]

The Svalbard archipelago is particularly sensitive to climate change due to the relatively low altitude of its main ice fields and its geographical location in the higher North Atlantic, where the effect of Arctic amplification is more significant. The largest temperature increases have been observed during winter, but increasing summer temperatures, above the melting point, have led to increased glacier melt. Here, we evaluate the impact of this increased melt on the preservation of the oxygen isotope (δ18 O) signal in firn records. δ18 O is commonly used as a proxy for past atmospheric temperature reconstructions, and, when preserved, it is a crucial parameter to date and align ice cores. By comparing four different firn cores collected in 2012, 2015, 2017 and 2019 at the top of the Holtedahlfonna ice field (1100 m a.s.l.), we show a progressive deterioration of the isotope signal, and we link its degradation to the increased occurrence and intensity of melt events. Our findings indicate that, starting from 2015, there has been an escalation in melting and percolation resulting from changes in the overall atmospheric conditions. This has led to the deterioration of the climate signal preserved within the firn or ice. Our observations correspond with the model's calculations, demonstrating an increase in water percolation since 2014, potentially reaching deeper layers of the firn. Although the δ18 O signal still reflects the interannual temperature trend, more frequent melting events may in the future affect the interpretation of the isotopic signal, compromising the use of Svalbard ice cores. Our findings highlight the impact and the speed at which Arctic amplification is affecting Svalbard's cryosphere. [ABSTRACT FROM AUTHOR]

The Loess Plateau of China, located to the west of the Liupan Mountains and north of the Qinling Mountains stretching across the Yellow River, is the main loess deposit area in Northwest China. The loess in the northwest of China has deposits with large thickness and extensive distribution. Scanning electron microscopy (SEM) and energy spectrum analysis of loess have been performed to study the relationship between the loess microstructures and the forming climates Era. The relevant indexes were evaluated including the sand‐dropping speed (Vn), certain sedimentary depths (hn sand particle volume (Vd) and element ratios of Ca/Fe, K/Al, Si/Al and Ca/Mg. The microstructure indexes of loess accumulation and evolution reflect paleoclimate conditions and time scales to a certain extent. The important discovery is the microscopic sand‐dropping speed (Vn) and the sedimentary depth hn) calculation method of different sedimentary ages. These indices are compared with the record of major aeolian‐forming climates from the Guliya ice core, and provide a reliable benchmark for studying climate change It also can be used as important indicators of monsoonal change and environmental evolution reconstruction. The index of sand sedimentation speed (Vn) got from loess microstructure could reflect sand‐dropping speed and loess deposition course. According the article can serve as new indicators of climatic changes of different forming loess layers. It can also be concluded that the climatic indexes obtained from loess microstructure can reflect climate conditions of loess forming. The loess forming climatic parameters are synchronous correspond to Tengger Desert and Guliya ice core for studying climate change, then microscopic parameters can also be used for preliminary analysis of loess climate formation and has be found corresponding evidence, and the loess climatic parameters correspond to the other two indexes. The analysis of loess microstructure indexes is very useful in researching climate change. Loess microstructure indexes can find new indicators and information about the monsoon climate evolution and paleoclimate changes. [ABSTRACT FROM AUTHOR]

The data on the content of the 10Be cosmogenic isotope in the GISP2 Greenland ice core are presented. The reconstruction of the heliospheric modulation potential (HMP) was carried out for 6000–1348 BC. A systematic decrease in the HMP over this time interval was found, which corresponds to a decrease in global surface temperature after 3000 BC and a decrease in the HMP obtained from radiocarbon data in previous studies. Thus, the decline in global temperature after 3000 AD could be caused by a decrease in solar activity. [ABSTRACT FROM AUTHOR]

Very high tropical alpine ice cores provide a distinct paleoclimate record for climate changes in the middle and upper troposphere. However, the climatic interpretation of a key proxy, the stablewater oxygen isotopic ratio in ice cores (d18Oice), remains an outstanding problem. Here, combining proxy records with climate models, modern satellite measurements, and radiative-convective equilibrium theory, we show that the tropical d18Oice is an indicator of the temperature of the middle and upper troposphere, with a glacial cooling of -7.35° ± 1.1°C (66% CI). Moreover, it severs as a "Goldilocks-type" indicator of global mean surface temperature change, providing the first estimate of glacial stage cooling that is independent of marine proxies as -5.9° ± 1.2°C. Combined with all estimations available gives the maximum likelihood estimate of glacial cooling as -5.85° ± 0.51°C. [ABSTRACT FROM AUTHOR]

Seasonal temperature reconstructions from ice cores are missing over glacial-interglacial timescales, preventing a good understanding of the driving factors of Antarctic past climate changes. Here the total air content (TAC) record from an Antarctic ice core is analyzed over the last 440 thousand of years (ka). While the water isotopic record, tracer for annual mean surface temperature, exhibits a dominant ~100 ka cyclicity, the TAC record is associated with a dominant ~40 ka cyclicity. Our results show that the TAC record is highly correlated with the mean insolation over the local astronomical half-year summer. It also shows for the first time that it is highly correlated with local summer temperature simulated with an Earth system model of intermediate complexity. This suggests that the Antarctic TAC records could be used as a proxy for local summer temperature changes. Also, our simulations show that local summer insolation is the primary driver of Antarctic summer surface temperature variations while changes in atmospheric greenhouse gas concentrations and northern hemisphere ice sheet configurations play a more important role on Antarctic annual surface temperature changes. [ABSTRACT FROM AUTHOR]

This paper presents the first continuous (gap-free) Late Glacial-Early Holocene (LGEH) pollen record for the Iberian Pyrenees resolved at centennial resolution. The main aims are (i) to provide a standard chronostratigraphic correlation framework, (ii) to unravel the relationships between vegetation shifts, climatic changes and fire, and (iii) to obtain a regional picture of LGEH vegetation for the Pyrenees and the surrounding lowlands. Seven pollen assemblage zones were obtained and correlated with the stadial/interstadial phases of the Greenland ice cores that serve as a global reference. Several well-dated datums were also derived for keystone individual taxa that are useful for correlation purposes. Four vegetation types were identified, two of them corresponding to conifer and deciduous forests (Cf, Df) and two representing open vegetation types (O1, O2) with no modern analogs, dominated by Artemisia-Poaceae and Saxifraga-Cichorioideae, respectively. Forests dominated during interstadial phases (Bølling/Allerød and Early Holocene), whereas O1 dominated during stadials (Oldest Dryas and Younger Dryas), with O2 being important only in the first half of the Younger Dryas. The use of pollen-independent proxies for temperature and moisture allowed the reconstruction of paleoclimatic trends and the responses of the four vegetation types defined. The most relevant observation in this sense was the finding of wet climates during the Younger Dryas, which challenges the traditional view of arid conditions for this phase on the basis of former pollen records. Fire incidence was low until the Early Holocene, when regional fires were exacerbated, probably due to the combination of higher temperatures and forest biomass accumulation. These results are compared with the pollen records available for the whole Pyrenean range and the surrounding lowlands within the framework of elevational, climatic and biogeographical gradients. Some potential future developments are suggested on the basis of the obtained results, with an emphasis on the reconsideration of the LGEH spatiotemporal moisture patterns and the comparison of the Pyrenees with other European ranges from different climatic and biogeographical regions. [ABSTRACT FROM AUTHOR]

High-resolution stable isotope records obtained from Antarctic ice cores can be used as proxies to investigate past climatic changes in Antarctica, overcoming the spatiotemporal limitations of observational and instrumental records. Here, we used a new high-resolution ice core stable isotope record (1709–2001 AD) obtained from the Lambert Glacier Basin 69 (LGB69) site and a published stable isotope record (1757–1987 AD) from coastal Princess Elizabeth Land (PEL) to reconstruct temperature variability in the coastal region of PEL over the past three centuries. The dominant moisture source region for coastal PEL is mid-high latitudes of the South Indian Ocean (SIO) and this has remained stable over the past three centuries. Owing to non-climatic noise, no statistically significant isotope‒temperature relationship can be evidenced at annual-to-decadal scales. However, the ice core δD records do enable us to reconstruct multi-decadal temperature variability in the coastal region of PEL. The temperature reconstructions showed a consistent warming trend during the 20th century, whereas the cold periods prior to the 20th century may be related to the Little Ice Age (LIA). Our reconstructions exhibit high reliability, evidenced by their agreement with previous reconstructions from PEL. We also found that annual temperature variability is related to the Southern Annular Mode (SAM), whereas multi-decadal temperature variability is related to the Indian Ocean Dipole (IOD). However, the relationship between the SAM and temperature is unclear before the 1970s. The results of this study are helpful in understanding long-term temperature changes in Antarctica and provide an important reference for the attribution of temperature changes. [ABSTRACT FROM AUTHOR]

This visual essay presents drawings related to a research project that sought to develop a visual language that communicates the precarity of clothing items that have emerged from alpine glaciers in Europe. These artworks achieve a poetic effect that recalls the tensions and challenges of preserving these artifacts of glacial archaeology. This essay focuses on selected drawings of footwear from the exhibition Emergency! at Drawing Projects UK (November 10, 2022–February 4, 2023) and articulates how drawing was used as a form of touching to imaginatively translate the experience of encountering these items of footwear into artworks. The artworks offer an example of how artistic engagement with museum collections can generate a creative response to traces of the past and invite reflection on the future of our planet. [ABSTRACT FROM AUTHOR]

Stable water isotopologues of snow, firn and ice cores provide valuable information on past climate variations. Yet single profiles are generally not suitable for robust climate reconstructions. Stratigraphic noise, introduced by the irregular deposition, wind-driven erosion and redistribution of snow, impacts the utility of high-resolution isotope records, especially in low-accumulation areas. However, it is currently unknown how stratigraphic noise differs across the East Antarctic Plateau and how it is affected by local environmental conditions. Here, we assess the amount and structure of stratigraphic noise at seven sites along a 120 km transect on the plateau of Dronning Maud Land, East Antarctica. Replicated oxygen isotope records of 1 m length were used to estimate signal-to-noise ratios as a measure of stratigraphic noise at sites characterised by different accumulation rates (43–64 mm w.e. a -1), snow surface roughnesses and slope inclinations. While we found a high level of stratigraphic noise at all sites, there was also considerable variation between sites. At sastrugi-dominated sites, greater stratigraphic noise coincided with stronger surface roughnesses, steeper slopes and lower accumulation rates, probably related to increased wind speeds. These results provide a first step to modelling stratigraphic noise and might guide site selection and sampling strategies for future expeditions to improve high-resolution climate reconstructions from low-accumulation regions. [ABSTRACT FROM AUTHOR]

Polar snow and its accumulation preserve valuable information derived from the atmosphere on past climate and environmental changes in high resolution, particularly in coastal sites. A 2.5-m snow-pit was excavated from the coastal ice rise (Moore Dome) near Amundsen Sea region in February 2012. This study evaluated the isotopic and chemical compositions in the snow-pit and compared them with meteorological variables. Based on the seasonal peaks of the MSA and nssSO42- together with δ18O, δD, and d-excess, the snow-pit record was corresponded to accumulation during austral winter 2011 to summer 2011/2012. The annual mean accumulation rate was assumed thus to be as large as or even higher than 1.03 m w.e. yr-1 at this site. A relatively warm winter temperature in 2011 was traceable in the variations of δ18O, δD, and d-excess. This study emphasizes the importance of the high snow accumulation observed at this site in providing valuable information on sub-annual variations in climate and environmental changes through the study of longer ice cores. [ABSTRACT FROM AUTHOR]

The Laurentide Ice Sheet (LIS) was the largest ice sheet in the Northern Hemisphere during the last glacial cycle. The effects of its demise on global climate and sea‐level changes during the subsequent deglaciation are unequivocal. Understanding the interplay between ice sheets and long‐term or short‐term (e.g. abrupt) climatic events is therefore crucial for predicting future rates of ice sheet melting and their potential contribution to sea‐level changes. Here, we present 37 new 10Be surface exposure ages from easternmost Québec–Labrador that allow us to identify close ties between regional deglaciation history and climate. These results reveal that the LIS was disconnected from the Newfoundland Ice Cap by ~14.1 ka. Samples collected from moraine boulders indicate that this event was followed by five major stillstands and/or readvance stages of the LIS margin. Integrating our new moraine ages with those of earlier studies allows us to depict a temporal framework including events at ~12.9, ~11.5, ~10.4, ~9.3 and ~8.4–8.2 ka. These moraine ages highlight a strong sensitivity of the LIS to temperature changes in the Northern Hemisphere, as the documented continental ice margin stabilizations coincide with abrupt cooling events recorded in Greenland ice cores. These observations support the idea of a negative feedback mechanism induced by meltwater forcings into the North Atlantic Ocean which, in turn, provoked repeated cold reversals during the Younger Dryas and early Holocene. [ABSTRACT FROM AUTHOR]

Millennial-scale climate variations during the last glacial period, such as Dansgaard–Oeschger (D/O) cycles and Heinrich events, have been extensively studied using ice core and marine proxy records. However, there is a limited understanding of the magnitude of these temperature fluctuations in continental regions, and questions remain about the seasonal signal of these climate events. This study presents a 60,000-year long temperature reconstruction based on branched glycerol dialkyl glycerol tetraethers (brGDGTs) extracted from lake sediments from the Eifel volcanic field, Germany. brGDGTs are bacterial membrane lipids that are known to have strong relationship with temperature, making them suitable for temperature reconstructions. We test several temperature calibration models on modern samples taken from soils and multiple maar lakes. We find a bias associated with water depth and anoxic conditions that can be corrected for by accounting for a brGDGT isomer that is only produced in anoxic conditions. The corrected temperature reconstruction correlates with proxy and model temperature record spanning the same time period, validating the calibration model. However, millennial-scale variability is significantly dampened in the brGDGT record, and in contrast to other northern hemisphere climate records, during several Heinrich stadials, temperatures actually increase. We demonstrate that these apparent discrepancies can be explained by the unique seasonal response of the brGDGT paleothermometer to temperatures of months above freezing (TMAF). Our data support the view that warm season temperatures in Europe varied minimally during the last glacial period, and that abrupt millennial-scale events were defined by colder, longer winters. Our continuous high-resolution temperature reconstruction provides important information about the magnitude of seasonal climate variability during the last glacial period that can be used to test climate models and inform studies of paleoecological change. [ABSTRACT FROM AUTHOR]

Ice core records from Greenland provide evidence for multiple abrupt cold–warm– cold events recurring at millennial time scales during the last glacial interval. Although climate variations resembling Dansgaard–Oeschger (DO) oscillations have been identified in climate archives across the globe, our understanding of the climate and ecosystem impacts of the Greenland warming events in lower latitudes remains incomplete. Here, we investigate the influence of DO-cold-to-warm transitions on the global atmospheric circulation pattern. We comprehensively analyze δ18O changes during DO transitions in a globally distributed dataset of speleothems and set those in context with simulations of a comprehensive high-resolution climate model featuring internal millennial-scale variations of similar magnitude. Across the globe, speleothem δ18O signals and model results indicate consistent large-scale changes in precipitation amount, moisture source, or seasonality of precipitation associated with the DO transitions, in agreement with northward shifts of the Hadley circulation. Furthermore, we identify a decreasing trend in the amplitude of DO transitions with increasing distances from the North Atlantic region. This provides quantitative observational evidence for previous suggestions of the North Atlantic region being the focal point for these archetypes of past abrupt climate changes. [ABSTRACT FROM AUTHOR]

In this study, we have investigated the oxygen isotope compositions (δ17O and δ18O) of modern rain and ice cores using published isotopic data. We find that, contrary to existing interpretations, precipitation δ17O is influenced by two factors: mass-dependent fractionation (MDF), which occurs during ocean evaporation, and mass-independent fractionation (MIF), which happens in the stratosphere. The MDF contribution remains constant and can be understood by studying tropical rain, as the overall movement of mass in the tropics is upward toward the stratosphere. On the other hand, the MIF effect comes from the mixing of stratospheric air in the troposphere, which is a result of the Brewer–Dobson circulation. This MIF effect on precipitation 17O increases from the tropics toward the poles and is observed consistently in modern precipitation and ice cores. The relative δ17O and δ18O composition, denoted as ∆'17O, in modern precipitation can be calibrated with surface air temperature, creating a new and independent tool for estimating past temperatures. We used this calibration along with the ∆'17O of Antarctic and Greenland ice cores, and our reconstructed past temperatures are in excellent agreement with those derived from borehole thermometry or gas phase analysis of air trapped in the ice. The ∆'17O method overcomes the problems associated with using δ18O alone for paleothermometry. Our findings align with climate models that suggest a weakening of the Brewer–Dobson circulation during the Last Glacial Maximum. Furthermore, our approach could be used to monitor future changes in stratosphere–troposphere mass exchange in response to a warming climate caused by increasing greenhouse gases. [ABSTRACT FROM AUTHOR]

Shallow firn cores, in addition to a near-basal ice core, were recovered in 2018 from the Quelccaya ice cap (5470 m a.s.l) in the Cordillera Vilcanota, Peru, and in 2017 from the Nevado Illimani glacier (6350 m a.s.l) in the Cordillera Real, Bolivia. The two sites are ~450 km apart. Despite meltwater percolation resulting from warming, particle-based trace element records (e.g. Fe, Mg, K) in the Quelccaya and Illimani shallow cores retain well-preserved signals. The firn core chronologies, established independently by annual layer counting, show a convincing overlap indicating the two records contain comparable signals and therefore capture similar regional scale climatology. Trace element records at a ~1–4 cm resolution provide past records of anthropogenic emissions, dust sources, volcanic emissions, evaporite salts and marine-sourced air masses. Using novel ultra-high-resolution (120 μm) laser technology, we identify annual layer thicknesses ranging from 0.3 to 0.8 cm in a section of 2000-year-old radiocarbon-dated near-basal ice which compared to the previous annual layer estimates suggests that Quelccaya ice cores drilled to bedrock may be older than previously suggested by depth-age models. With the information collected from this study in combination with past studies, we emphasize the importance of collecting new surface-to-bedrock ice cores from at least the Quelccaya ice cap, in particular, due to its projected disappearance as soon as the 2050s. [ABSTRACT FROM AUTHOR]

A time series of 40.4~30.0cal ka BP for lacustrine sediment section was established by AMS14C dating method of four lacustrine sediment samples from a continuous sedimentary section in Qiongduojiang Basin in the southern Qinghai-Tibet Plateau. Combined with Granularity characteristics of sediments, fifty samples were collected from 5 to approximately 250cm lacustrine sediments and analyzed by total organic carbon (TOC) content, total nitrogen (TN) content, TOC/TN ratio and isotope of organic carbon (δ13C), and other environmental proxies. The paleoclimate evolution in the study area can be divided into five stages: the warm humid climate period (40.2~38.5ka BP), the warm arid climate period (38.5~35.4ka BP), the transition climate period (35.4~32.4ka BP), the volatility climate period (32.4~31.7ka BP), and shift to arid climate period (31.7~30.3ka BP). The average particle size (Mz) median diameter (Md) standard deviation (σ1) sorting coefficient and frequency distribution curve of sediment particle size was analyzed. It is found that the grain size curve has a good response to the oxygen isotope curve of Greenland ice core, and there were two significant climate events in Qiongduojiang Basin during the period of 40.4~30.0cal ka BP: 39.4cal Ka BP brief drought event and 35cal ka BP heavy precipitation event. The difference between the mean grain size curve and the oxygen isotope curve of Greenland ice core may be related to the extra strong summer monsoon. Spectrum analysis reveals that there are quasi-periodic climate variations of 1552a, 1187a, 961a, 602a, 538a and 492a from 40 to approximately 30ka BP in the study area. Climate change at the millennium scale may be related to the effects of solar activity, atmospheric circulation, oceanic internal instability, and monsoon activity. The identified 538a cycle corresponds to the 530a cycles of the solar activity, and therefore, the solar activity is also one of the causes of climate change in the Qiongduojiang basin. [ABSTRACT FROM AUTHOR]

Regions located on the Chinese Loess Plateau are sensitive to changes in the Asian monsoon because they are on the edge of the monsoon region. Based on six 230Th experiments and 109 sets of stable isotope data of LH36 from Lianhua Cave, Yangquan City, Shanxi Province, we obtained a paleoclimate record with an average resolution of 120 years from 54.5 to 41.1 ka BP during the MIS3 on the Chinese Loess Plateau. Both the Hendy test and the replication test indicated an equilibrium fractionation of stable isotopes during the stalagmite deposition. Comparison with four other independently-dated, high-resolution stalagmite δ13C records between 29°N and 41°N in the Asian monsoon region shows that the stalagmite δ13C records from different caves have good reproducibility during the overlapped growth period. We suggest that speleothem δ13C effectively indicates soil CO2 production in the overlying area of the cave, reflecting changes in the cave's external environment and in the Asian summer monsoon. Five millennial-scale Asian summer monsoon intensification events correspond to the Dansgaard–Oeschger 10–14 cycles recorded in the Greenland ice core within dating errors, and the weak monsoon processes are closely related to stadials in the North Atlantic. The spatial consistency of stalagmite δ13C records in China suggests that the Asian summer monsoon and the related regional ecological environment fluctuations sensitively respond to climate changes at northern high latitudes through sea-air coupling on the millennial timescale. [ABSTRACT FROM AUTHOR]

The Tibetan Plateau is an important area for studying global climate change, but the answers to many scientific problems remain unknown. Here, we present new information from the lacustrine sedimentary record in the western Tibetan Plateau, related to the third most‐recent glaciations. Continuous sediment data, including sporopollen, particle size, total organic carbon, mass susceptibility, CaCO3, CaSO4, BaSO4 contents and chronological data, were reconstructed and revealed that climate and environmental conditions obviously and distinctly changed between 600 and 700 thousand years ago. In comparison, the data obtained from the Guliya ice core in this area also corresponds to the global glacial climatic characteristics recorded in basin sediments in the eastern and southeastern regions of the plateau and to the information obtained from ice cores in the Antarctic and Arctic regions. In this study, we conclude that the main reason for the glaciations and new tectonic movement must be a geomagnetic polarity reversal 774 thousand years ago (from Matuyama to Brunhes). Indeed, the results of this study suggest that the described reversal event might have influenced the current global climate pattern and will continue to impact climatic changes in the future. [ABSTRACT FROM AUTHOR]

The ocean's immense ability to store and release heat on centennial to millennial time scales modulates the impacts of climate perturbations. To gain a better understanding of past variations in mean ocean temperature (MOT), a noble gas‐based proxy measured from ancient air in ice cores has been developed. Here we assess non‐temperature effects that may influence the atmospheric noble gas ratios reconstructed from polar ice and how they impact the temperature signal with an intermediate complexity Earth system model. We find that changes in wind speed, sea‐ice extent, and ocean circulation have partially compensating effects on mean‐ocean noble gas saturation, leading to a slight reduction of noble gas undersaturation at the Last Glacial Maximum (LGM). Taking these effects and ice core measurements into account, our model suggests a revised MOT difference between the LGM and pre‐industrial of −2.1 ± 0.7°C that is also in improved agreement with other independent temperature reconstructions. Plain Language Summary: Most of the heat added to the climate system by anthropogenic climate change is taken up by the oceans. To better understand how the ocean responds to climate change over hundreds to thousands of years, an indirect measure for the mean ocean temperature (MOT) based on the temperature‐dependent solubility of noble gases has been developed. Noble gas concentrations of the past atmosphere are archived in air bubbles in polar ice cores, which have been used to reconstruct the MOT of the past 20,000 years when Earth's climate was propelled out of the last ice age. However, uncertainties remain regarding critical parameters that are required to derive the correct MOT of the past. Here we make use of an Earth system model that explicitly simulates the noble gases and allows us to assess these parameters in detail under modern and past climate conditions. We find that changes in wind, sea‐ice, and ocean circulation all play important roles in the partitioning of noble gases between the atmosphere and ocean. By taking these effects into account our model suggests a revised best‐estimate MOT cooling of the last ice age to −2.1 ± 0.7°C, which is about 0.5°C warmer than previous estimates. Key Points: Revised implementation of noble gases in Bern3D model tuned to observations of saturation anomaliesComplex interplay between air‐sea gas exchange, overturning circulation, and noble gas saturationIncluding saturation effects noble gas‐based mean ocean temperature of the last glacial maximum is 2°C colder than the Holocene [ABSTRACT FROM AUTHOR]

The δ18O of ice core enclosed gaseous oxygen (δ18Obub) has been widely used for climate reconstruction in polar regions. Yet, less is known about its climatic implication in the mountainous glaciers as the lack of continuous record. Here, we present a long-term, continuous δ18Obub record from the Tanggula glacier in the central Tibetan Plateau (TP). Based on comparisons of its variation with regional climate and glacier changes, we found that there was a good correlation between the variation of the δ18Obub in this alpine ice core and the accumulation and melting of this glacier. The more developed the firn layer on glacier surface, the more positive the δ18Obub. Conversely, the more intense the glacier melting, the more negative the δ18Obub. Combined with the chronology of ice core enclosed gases, the glacier variations since the late Holocene in the central TP were reconstructed. The result showed that there were four accumulation and three deficit periods of glaciers in this region. The strongest glacier accumulation period was 1610-300 B.C., which corresponds to the Neoglaciation. The most significant melting period was the last 100 years, which corresponds to the recent global warming. The Medieval Warm Period was relatively significant in the central TP. However, during the Little Ice Age, there was no significant glacier accumulation in the central TP, and even short deficit events occurred. Comparisons of the late Holocene glacier variation in the central TP with glacier and climate variations in the TP and the Northern Hemisphere showed that it was closely related to the North Atlantic Oscillation. [ABSTRACT FROM AUTHOR]

East Siberia is a large region extending from Mongolia to the Arctic seas. The main atmospheric circulations of the Northern Hemisphere (the North Atlantic, Arctic and East Asia Oscillations) appear in this region. In addition, Lake Frolikha is situated at 55°N, and the high latitude area is sensitive to variation in insolation and solar activity. We analysed pollen, diatoms and mineralogical records of two sediment cores from Lake Frolikha, situated near Lake Baikal. According to AMS dating, the age of obtained paleo-records was ca. 5.5 ka BP. We interpreted these records in terms of changing regional precipitation, vegetation and lake bio-productivity. The Lake Frolikha records were compared with temperature records from Greenland ice cores (activity of North Atlantic Oscillation), the West Tropical Pacific (East Asian monsoon), the bio-productivity of lakes from China and Mongolia, oxygen isotope records from Chinese caves, and insolation at 60°N. We found that the records from Lake Frolikha related to four climate episodes that have occurred in the south part of East Siberia since the middle Holocene (5.5–4, 4–1.7, 1.7–0.8, 0.8–0 cal ka BP). [ABSTRACT FROM AUTHOR]

The 8.2 ka event has been extensively studied, whereas its structure is ambiguous in North China. Here we present a high‐resolution (∼1 year) δ18O record from annual laminated speleothem from Beijing to characterize the detailed variability across this event in North China. Our record indicates a dry 8.2 ka event spanning 8.254–8.107 ka BP with a two‐stage structure superimposed by three prominent high δ18O excursions. The identical structure of speleothem δ18O records between North and central China during the event suggests a common forcing/response in East China, whereas the progressively increased offset between their average values may reflect changes in moisture source or rainout effect. A close comparison with the Greenland ice core records suggests a strong linear response of the Asian summer monsoon to the North Atlantic climate changes across the early and middle stages of the event, but a different mechanism in the termination processes. Plain Language Summary: As the most pronounced abrupt climate event in the Holocene, the 8.2 ka event has been studied using various geological archives worldwide, but its detailed structure in North China and its link to other climate systems remain poorly understood. Since the Beijing speleothem δ18O, a proxy of the precipitation δ18O, is sensitive to the Asian summer monsoon (ASM) variations, it allows us to establish precise timing and structure of the 8.2 ka event and estimate the cause of it. Our new speleothem δ18O record from Beijing reveals a two‐stage structure superimposed by three "V‐shape" excursions during the event and almost exactly covaries with another published speleothem record from central China, suggesting coherent climate changes over the east ASM domain in response to the same forcing. The gradually increased offset between them probably results from the changed atmospheric circulations. Our results suggest a fast climatic signal propagation from the North Atlantic to the ASM domain during the early and middle 8.2 ka event, and another forcing mechanism in the termination processes. Key Points: Annual laminated speleothem δ18O record from North China manifests a two‐stage 8.2 ka event superimposed by three positive excursionsHigh consistency in speleothem records from North and central China on interdecadal to multidecadal timescales indicates a common driverThe climate forcing for the termination process is different from the early and middle stages of the 8.2 ka event [ABSTRACT FROM AUTHOR]

Copyright of Chinese Journal of Inorganic Analytical Chemistry / Zhongguo Wuji Fenxi Huaxue is the property of Beijing Research Institute of Mining & Metallurgy Technology Group and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Atmospheric methane (CH 4) concentrations have gone through rapid changes since the last deglaciation; however, the reasons for abrupt increases around 14,700 and 11,600 years before present (yrs BP) are not fully understood. Concurrent with deglaciation, sea-level rise gradually inundated vast areas of the low-lying Beringian shelf. This transformation of what was once a terrestrial-permafrost tundra-steppe landscape, into coastal, and subsequently, marine environments led to new sources of CH 4 from the region to the atmosphere. Here, we estimate, based on an extended geospatial analysis, the area of Beringian coastal wetlands in 1000-year intervals and their potential contribution to northern CH 4 flux (based on present day CH 4 fluxes from coastal wetland) during the past 20,000 years. At its maximum (∼14,000 yrs BP) we estimated CH 4 fluxes from Beringia coastal wetlands to be 3.5 (+4.0/-1.9) Tg CH 4 yr−1. This shifts the onset of CH 4 fluxes from northern regions earlier, towards the Bølling-Allerød, preceding peak emissions from the formation of northern high latitude thermokarst lakes and wetlands. Emissions associated with the inundation of Beringian coastal wetlands better align with polar ice core reconstructions of northern hemisphere sources of atmospheric CH 4 during the last deglaciation, suggesting a connection between rising sea level, coastal wetland expansion, and enhanced CH 4 emissions. • First estimation of Beringian coastal wetland methane flux. • Methane fluxes were 1.4–3.5 Tg CH 4 yr−1 for the past 20,000 years. • Beringian coastal wetlands shift the onset of CH 4 fluxes from northern regions. • >200,000 km2 of wetlands were close to sea level during major climatic changes. [ABSTRACT FROM AUTHOR]

Biomass burning drives changes in greenhouse gases, climate-forcing aerosols, and global atmospheric chemistry. There is controversy about the magnitude and timing of changes in biomass burning emissions on millennial time scales from preindustrial to present and about the relative importance of climate change and human activities as the underlying cause. Biomass burning is one of two notable sources of ethane in the preindustrial atmosphere. Here, we present ice core ethane measurements from Antarctica and Greenland that contain information about changes in biomass burning emissions since 1000 CE (Common Era). The biomass burning emissions of ethane during the Medieval Period (1000-1500 CE) were higher than present day and declined sharply to a minimum during the cooler Little Ice Age (1600-1800 CE). Assuming that preindustrial atmospheric reactivity and transport were the same as in the modern atmosphere, we estimate that biomass burning emissions decreased by 30 to 45% from the Medieval Period to the Little Ice Age. The timing and magnitude of this decline in biomass burning emissions is consistent with that inferred from ice core methane stable carbon isotope ratios but inconsistent with histories based on sedimentary charcoal and ice core carbon monoxide measurements. This study demonstrates that biomass burning emissions have exceeded modern levels in the past and may be highly sensitive to changes in climate.

Rising sea levels are mainly due to increases in environmental temperatures that are causing ice to melt. The weathering of geomaterials is mainly due to the increase in the concentration of greenhouse gases in the atmosphere. This research addresses current and future sea level rises and their weathering effects on the building stones in the Phoenician–Punic archaeological area of Nora (Sardinia, Italy). Some forecasting models, selected according to real-world scenarios (shared socioeconomic pathways—SSPs), give a definitive overview of both the rising sea levels and stone weathering conditions in Nora. The year 2100 A.D. was selected as the base of our investigations because the SSPs are scenarios of projected socioeconomic global changes up to 2100 A.D. The data on the expected alteration of geomaterials were reconstructed by considering the temperatures, the rainfall amount, and the atmospheric CO2 of every scenario. This was made possible by knowing the current degree of alteration of the geomaterials and their weathering resistance. The rising sea level models were obtained through the SSPs scenarios data and built using geographic information systems software. The projections show a slowing down of the weathering degrees of the stone materials in Nora. This is due to the increase in the average annual temperature and the decrease in the average annual rainfall. However, it is shown that some other factors, such as the marine spray in the area, could accelerate the decay. Projections of the rising sea levels show how the settlement will be partially submerged, losing between 3.54% and 8.49% of the emerged land. The models provided a maximum ingression of the coastline, ranging from 23.7 m to 29.5 m, based on the severity of the scenarios. Coastline-shifting maps indicate the flooding of some buildings located on the western coast of Nora, the most sensitive part of the territory. [ABSTRACT FROM AUTHOR]

A new, seasonal, laminated ice core pollen record spanning the last 13 years (2000--2012) from Zuoqiupu Glacier (5,600 m a.s.l.), located on the southeastern Tibetan Plateau (TP), reveals clear variations in pollen concentration and assemblage. A total of 117 continuous ice core layers were used for pollen analysis. Samples with high concentrations of Pinus and Tsuga could be identified as layers accumulated in spring, samples with high concentrations of Alnus and Artemisia could be identified as layers accumulated in autumn, and samples rich in herbaceous plant pollen could be regarded as layers deposited in summer. Three peaks of Tsuga pollen concentration accompanied by high Pinus content occurred in the spring of 2003, 2007, and 2010, which corresponded to wetter and warmer conditions modulated by the El Niño decaying phase (April--May in 2003, 2007, and 2010). Thus, pollen grains deposited on the Zuoqiupu Glacier can be used to study the impacts of atmospheric circulations on seasonal climate change over the southeastern TP. [ABSTRACT FROM AUTHOR]

Numerous loess/paleosol sequences (LPS) in the Carpathian Basin span the period of Marine Isotope Stage (MIS) 2 and the last glacial maximum (LGM). Nevertheless, only two known records—Madaras and Dunaszekcső—preserve highly resolved records with absolute chronologies with minimal uncertainties, which enable the meaningful assessment of feedbacks and short-term climatic fluctuations over this period. The Madaras profile is located at the northern margin fringe of the Bácska loess plateau; Dunaszekcső, located on the Danube to its west, yields a chronology built on over 100 14C dates yet spans only part of MIS 2, missing half of the LGM including its peak. Here, we add to the previously published 14C chronology for Madaras (15 dates) with an additional 17 14C and luminescence ages. Resulting age models built solely on quartz OSL and feldspar pIRIRSL data underestimate the 14C based chronology, which is likely based on inaccuracies related to luminescence signal behavior; we observe age underestimations associated with unusual quartz behavior and significant signal loss, a phenomenon also observed in Serbian and Romanian loess, which may relate to non-sensitized grains from proximal sources. Our new chronology provides higher resolution than hitherto possible, yielding consistent 2 sigma uncertainties of ~150–200 years throughout the entire sequence. Our study indicates that the addition of further dates may not increase the chronological precision significantly. Additionally, the new age model is suitable for tackling centennial-scale changes. The mean sedimentation rate based on our new age-depth model (10.78 ± 2.34 years/cm) is the highest yet recorded in the Carpathian Basin for MIS 2. The resolution of our age model is higher than that for the Greenland NGRIP ice core record. The referred horizons in our profile are all characterized by a drop in accumulation and a higher sand input, the latter most likely deriving from nearby re-exposed sand dunes. [ABSTRACT FROM AUTHOR]

While a significant influence of volcanic activity on Holocene climate is well-established, an equally prominent role of major eruptions in the climate variability and regime shifts during the Quaternary glacial cycles has been suggested. Previous statistical assessments of this were challenged by inaccurate synchronization of large volcanic eruptions to changes in past climate. Here, this is alleviated by combining a new record of bipolar volcanism from Greenland and Antarctic ice cores with records of abrupt climate change derived from the same ice cores. We show that bipolar volcanic eruptions occurred significantly more frequently than expected by chance just before the onset of Dansgaard–Oeschger events, which are the most prominent large-scale abrupt climate changes in the last glacial period. Out of 20 abrupt warming events in the 12–60 ka period, 5 (7) occur within 20 (50) years after a bipolar eruption. We hypothesize that this may be a result of the direct influence of volcanic cooling on the Atlantic meridional overturning circulation, which is widely regarded as the main climate subsystem involved in Dansgaard–Oeschger cycles. Transitions from a weak to a strong circulation mode may be triggered by cooling in the North Atlantic given that the circulation is close to a stability threshold. We illustrate this suggestion by simulations with an ocean-only general circulation model forced by short-term volcanic cooling. The analysis presented suggests that large eruptions may act as short-term triggers for large-scale abrupt climate change and may explain some of the variability of Dansgaard–Oeschger cycles. While we argue that the bipolar catalogue used here covers a sufficiently large portion of the eruptions with the strongest global climate impact, volcanic events restricted to either the Northern or Southern Hemisphere may likewise contribute to abrupt climate change. [ABSTRACT FROM AUTHOR]

A new ice core was drilled in West Antarctica on Skytrain Ice Rise in field season 2018/2019. This 651 m ice core is one of the main targets of the WACSWAIN (WArm Climate Stability of the West Antarctic ice sheet in the last INterglacial) project. A present-day accumulation rate of 13.5 cm w.e. yr -1 was derived. Although the project mainly aims to investigate the last interglacial (115–130 ka), a robust chronology period covering the recent past is needed to constrain the age models for the deepest ice. Additionally, this time period is important for understanding current climatic changes in the West Antarctic region. Here, we present a stratigraphic chronology for the top 184.14 m of the Skytrain ice core based on absolute age tie points interpolated using annual layer counting encompassing the last 2000 years of climate history. Together with a model-based depth–age relationship of the deeper part of the ice core, this will form the ST22 chronology. The chemical composition, dust content, liquid conductivity, water isotope concentration and methane content of the whole core was analysed via continuous flow analysis (CFA) at the British Antarctic Survey. Annual layer counting was performed by manual counting of seasonal variations in mainly the sodium and calcium records. This counted chronology was informed and anchored by absolute age tie points, namely, the tritium peak (1965 CE) and six volcanic eruptions. Methane concentration variations were used to further constrain the counting error. A minimal error of ±1 year at the tie points was derived, accumulating to ± 5 %–10 % of the age in the unconstrained sections between tie points. This level of accuracy enables data interpretation on at least decadal timescales and provides a solid base for the dating of deeper ice, which is the second part of the chronology. [ABSTRACT FROM AUTHOR]

Sea ice decline in the North Atlantic and Nordic Seas has been proposed to contribute to the repeated abrupt atmospheric warmings recorded in Greenland ice cores during the last glacial period, known as Dansgaard-Oeschger (D-O) events. However, the understanding of how sea ice changes were coupled with abrupt climate changes during D-O events has remained incomplete due to a lack of suitable high-resolution sea ice proxy records from northwestern North Atlantic regions. Here, we present a subdecadal-scale bromine enrichment (Brenr) record from the NEEM ice core (Northwest Greenland) and sediment core biomarker records to reconstruct the variability of seasonal sea ice in the Baffin Bay and Labrador Sea over a suite of D-O events between 34 and 42 ka. Our results reveal repeated shifts between stable, multiyear sea ice (MYSI) conditions during cold stadials and unstable, seasonal sea ice conditions during warmer interstadials. The shift from stadial to interstadial sea ice conditions occurred rapidly and synchronously with the atmospheric warming over Greenland, while the amplitude of high-frequency sea ice fluctuations increased through interstadials. Our findings suggest that the rapid replacement of widespread MYSI with seasonal sea ice amplified the abrupt climate warming over the course of D-O events and highlight the role of feedbacks associated with late-interstadial seasonal sea ice expansion in driving the North Atlantic ocean-climate system back to stadial conditions. [ABSTRACT FROM AUTHOR]

Copyright of Arid Zone Research / Ganhanqu Yanjiu is the property of Arid Zone Research Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Portraying Climate Change and Ocean Health K.A. Colorado Ice Core Sculptures My proprietary series of Ice Core Sculptures attracted the attention of the National Oceanic and Atmospheric Administration (NOAA) and its Office of National Marine Sanctuaries (National Marine Sanctuary Foun-dation), which invited me in 2015 to become their Artist-in-Residence and to create a sculpture for their National Marine Sanctuary System. Ice Cubed I "Human fingerprints on the Antarctic, i I the evidence is apparent now to see. i I Disposable plastics burning, i I deforestation and carbon increases, i I methane emissions to flee. i I Ice don't leave yet, i I hold tight and don't regret i I the Anthropocene, i I retreating in reluctant defeat." i - Edited excerpt from the poem "Visiting Ice" by K.A. Colorado As a sculptor and painter, I have taken the opportunity to develop my art on the climate subject and hope to expand the relationship of visual arts to the beauty and fragility of climate. The I Ice Core Sculptures i are a series of three-dimensional acrylic sculptures that visualize and emulate scientific ice core samplings. (Photos of Pyramid Sculpture courtesy of Lourdes Reátiga) Ice Cores Imbedded with Scientific Data, Dialogue, and DNA Ice Core Sculpture Series The I Ice Cores Series i of sculptures, paintings, and prints was begun in 2006 following a trip to the polar region during which I observed scientists drilling ice cores and arranging them for study. [Extracted from the article]

The curators resist chronologies, representing these connections through a diverse array of objects created from, representative of, or in pursuit of understanding Australia's environment. The third chapter of the exhibition is most reflective of a traditional "natural history" exhibit (not least due to the three life-like orcas suspended from the ceiling). Upon entering the National Museum of Australia's refurbished environment gallery, I Great Southern Land i , you are flanked by the mammoth trunks of Bunya pines ( I Araucaria bidwillii i ). [Extracted from the article]