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Based on daily high-resolution temperature observations at 1941 meteorological stations in China from 1980 to 2023, stations reaching standard for cold wave and 418 cold wave processes (including 152 strong cold waves processes) in winter are identified according to the monitoring indices of cold air processes. And cold wave processes are objectively classified according to their intensity and influencing areas using K-means++ clustering method. The temporal and spatial characteristics of the single-station cold waves and 418 cold wave events are discussed. Results show that the frequency of cold waves in the high affecting areas of China has not increased significantly but has shown a decreasing trend over the last 40 years. The increasing trend of frequency and intensity of single-station cold waves in the middle-lower reaches of the Yangtze River Plain is significant. Additionally, the intensity of single-station cold waves in South China is also noticeably enhanced. The frequency of winter cold wave events in China has decreased significantly in the last 40 years with an expanding range of influence, while the intensity of strong cold wave events has increased significantly, accompanied by a marked increase in the amplitude of interannual variations. The cold air associated with cold waves in China mainly originates from the southeast of Novaya Zemlya, and its trajectory varies depending on the type of cold wave. Based on the fifth-generation European Centre for Medium-Range Weather Forecasts (ECMWF) atmospheric reanalysis data (ERA5), characteristics of atmospheric circulation anomalies in the preceding and the simultaneous period for cold wave processes in the countrywide, Northeast-North China and Northwest-North China are analyzed. It is found that the deep warm high pressure in Greenland is an important precursor of the countrywide cold wave, and the zonal wave train in the middle and upper troposphere of Eurasia is a prominent feature of the cold wave outbreak. The cold wave in Northeast-North China is related to the eastward movement of the cold vortex under the block of anomalous high-pressure system in the mid-low latitudes. The cold wave in Northwest-North China is closely related to the development of a warm high ridge over the East European Plain and the circulation situation of two-ridge-one-trough in mid-high latitudes of Eurasia. All types of cold waves are preceded by the maintenance of the Ural blocking high and the accumulation of cold air in Siberia.

Over the modern satellite era, substantial climatic changes have been observed in the Antarctic, including atmospheric and oceanic warming, ice sheet thinning and a general Antarctic-wide expansion of sea ice, followed by a more recent rapid loss. Although these changes, featuring strong zonal asymmetry, are partially influenced by increasing greenhouse gas emissions and stratospheric ozone depletion, tropical–polar teleconnections are believed to have a role through Rossby wave dynamics. In this Review, we synthesize understanding of tropical teleconnections to the Southern Hemisphere extratropics arising from the El Niño–Southern Oscillation, Interdecadal Pacific Oscillation and Atlantic Multidecadal Oscillation, focusing on the mechanisms and long-term climatic impacts. These teleconnections have contributed to observed Antarctic and Southern Ocean changes, including regional rapid surface warming, pre-2015 sea ice expansion and its sudden reduction thereafter, changes in ocean heat content and accelerated thinning of most of the Antarctic ice sheet. However, due to limited observations and inherent model biases, uncertainties remain in understanding and assessing the importance of these teleconnections versus those arising from greenhouse gases, ozone recovery and internal variability. Sustained pan-Antarctic efforts towards long-term observations, and more realistic dynamics and parameterizations in high-resolution climate models, offer opportunities to reduce these uncertainties.

Ice-core water isotopes contain valuable information on past climate changes. However, such information can be altered by post-depositional processing after snow deposition. Atmosphere–snow water vapor exchange is one such process, but its influence remains poorly constrained. Here we constructed a box model to quantify the atmosphere–snow water vapor exchange fluxes and the associated isotope effects at sites with low snow accumulation rates, where the effects of atmosphere–snow water vapor exchange are suspected to be large. The model reproduced the observed diurnal variations in δ18O , δD , and deuterium excess (d-excess) in water vapor at Dome C, East Antarctica. According to the same model framework, we found that under average summer clear-sky conditions, atmosphere–snow water vapor exchange at Dome A can cause diurnal variations in atmospheric water vapor δ18O and δD of 4.8 ‰ ± 2.6 ‰ and 29 ‰ ± 19 ‰, with corresponding diurnal variations in surface snow δ18O and δD of 0.80 ‰ ± 0.35 ‰ and 1.6 ‰ ± 2.7 ‰. The modeled results under summer cloudy conditions display similar patterns to those under clear-sky conditions but with much smaller magnitudes of diurnal variations. However, under winter conditions at Dome A, the model predicts few to no diurnal changes in snow isotopes, consistent with the stable boundary condition in winter that inhibits effective vapor exchange between the atmosphere and snow. In addition, after 24 h and continuous simulations of 11 d, the model predicts significant enrichments in snow isotopes under summer conditions, while in winter, the depletions also accumulate after each 24 h simulation but with a much smaller magnitude of change compared to the results from summer simulations. If the modeled snow isotope enrichments in summer conditions and the depletions in winter conditions represent the general situation at Dome A, this likely suggests that atmosphere–snow water vapor exchange tends to increase snow isotope seasonality, and the annual net effect would be overall enrichments in snow isotopes since the effects in summer appear to be greater than those in winter. This trend will need to be further explored in the future with more comprehensive model studies and/or field observations and experiments. [ABSTRACT FROM AUTHOR]

The risk of water erosion in mainland China is intensifying due to climate change. A high-precision rainfall erosivity dataset is crucial for revealing the spatiotemporal patterns of rainfall erosivity and identifying key areas of water erosion. However, due to the insufficient spatiotemporal resolution of historical precipitation data, there are certain biases in the estimation of rainfall erosivity in China, especially in regions with complex terrain and climatic conditions. Over the past decade, the China Meteorological Administration has continuously improved its ground-based meteorological observation capabilities, forming a dense network of ground-based observation stations. These high-precision precipitation data provide a solid foundation for quantifying the patterns of rainfall erosivity in China. In this study, we first performed rigorous quality control on the 1-minute ground observation precipitation data from nearly 70,000 stations nationwide from 2014 to 2022, ultimately selecting 60,129 available stations. Using the precipitation data from these stations, we calculated event rainfall erosivity and generated a national mean annual rainfall erosivity dataset with a spatial resolution of 0.25°. This dataset shows that the mean annual rainfall erosivity in mainland China is approximately 1241 MJ·mm·ha−1·h−1·yr−1, with areas exceeding 4000 MJ·mm·ha−1·h−1·yr−1 mainly concentrated in the southern China and southern Tibetan Plateau. Compared to our study, previously released datasets overestimate China's mean annual rainfall erosivity by 31 %~65 %, and there are significant differences in performance across different river basins. In summary, the release of this dataset facilitates a more accurate assessment of the current water erosion intensity in China. The dataset is available from the National Tibetan Plateau/Third Pole Environment Data Center (https://doi.org/10.11888/Terre.tpdc.301206 ; Chen, 2024). [ABSTRACT FROM AUTHOR]

In this study, we apply a three‐dimensional (3D) thermomechanically coupled higher‐order ice flow model to simulate the East Rongbuk Glacier (ERG), Mt. Everest. We first diagnostically investigate its present‐day ice dynamic features in 2009 and then prognostically simulate the glacier during the time period 2010–2100. The ice flow model is initialized based on a Robin‐type inversion method by conducting six sensitivity experiments relating to glacier thermal boundary conditions. We apply two different surface mass balance parameterizations in the model, and both of them can reproduce the observed ice volume loss (around 0.1 km3) during 2010–2020. We find that ERG is likely to experience maximum meltwater runoff at the year 2030 under the SSP‐126 scenario, while under SSP‐370 and ‐585 scenarios, the peak water will both likely occur at around 2060. The ice dynamics may contribute more to ice loss as climate warms in time. Plain Language Summary: The melt of glaciers in High Mountain Asia (HMA) has great impacts on regional water resources and socioeconomy. But it is not an easy task to accurately predict their future changes. The East Rongbuk Glacier (ERG), Mt. Everest, is one of few glaciers in HMA that has relatively rich in situ data for conducting three‐dimensional numerical projections. In this study, we first carefully invert basal frictions at the ice‐bed interface according to observed ice surface velocities as a model initialization. Then, we drive the model and simulate the changes of ERG from 2010 to 2100. We validate our model by comparing our simulation results to observed ice volume loss during 2010–2020. We find that ERG will reach its maximum meltwater runoff at around 2030 and 2060 for the lower (SSP‐126) and higher (SSP‐585) emission scenarios, respectively. Key Points: We conduct diagnostic and prognostic simulations of East Rongbuk Glacier, Mt. EverestThe use of Robin inversion method during initialization suggests the presence of temperate basal iceWe find East Rongbuk Glacier will likely reach maximum meltwater runoff around the middle of this century [ABSTRACT FROM AUTHOR]

Using repeat GPS measurements during 2005–16, we calculated and updated two-dimensional high-resolution decadal ice surface velocity estimates along the traverse route from Zhongshan Station to and around Dome Argus, East Antarctica. Along the 71 sites of the transect, the magnitudes of ice velocity increased from near 0 in Dome Argus to 1, 10 and ~100 m a−1 at the sites DT416, DT333 and LT980, respectively. The comparison between GPS and interferometric synthetic aperture radar (InSAR) derived results agree well when the magnitude of the ice surface velocities is faster than 5 m a−1, and disagree for slower flow velocities. A scale value 1.15 and 0.12 can be applied to InSAR derived results over this region with ice surface velocity larger and

This study, utilizing ERA5 data from 1979 to 2021, identifies a prevalent occurrence of blocking events in East Antarctica, particularly in the region extending from Wilkes Land to Dronning Maud Land. The genesis of these blocking highs is typically facilitated by the intensification of Rossby waves within the circumpolar westerlies. By classifying the circulation patterns causing the blocking events, the blocking events in East Antarctica are divided into five categories. On the western flank of the blocking high, we observe the transportation of warm and humid air into inland Antarctica, instigating regional snowfall. High precipitation levels are observed in different regions based on the specific location of the blocking high. We also demonstrate that the contribution of atmospheric blockings to total annual precipitation and extreme precipitation events increases from coastal to inland. Over the East Antarctic plateau, the blockings are responsible for at least 15% of total accumulated snowfall and 30% of extreme precipitation events. Finally, we find a significant relationship between the interannual variability in East Antarctic blocking frequency and the phase variability of the Southern Annular Mode (SAM). A positive phase of the SAM inhibits an increase in blocking frequency, while a negative phase favors an increase. However, the two Pacific–South American patterns (PSA-1 and PSA-2), characterized by wave trains originating in the tropical Pacific that extend across the Southern Hemisphere extratropics, do not significantly influence the interannual variability in East Antarctic blocking frequency. [ABSTRACT FROM AUTHOR]