In November 1984,China launched its first expedition to the Southern Ocean and the Antarctic continent,culminating in the establishment of its first year-round research station—Great Wall Station—on the Antarctic Pe...In November 1984,China launched its first expedition to the Southern Ocean and the Antarctic continent,culminating in the establishment of its first year-round research station—Great Wall Station—on the Antarctic Peninsula in February 1985.Forty years later,in February 2024,China’s fifth research station,Qinling Station,commenced operations on Inexpress-ible Island near Terra Nova Bay.展开更多
Black carbon (BC) aerosols are considered key factors that contribute to rapid climate warming and ice melt in the Arctic region.However,compared with long-term observations from land-based stations,observational data...Black carbon (BC) aerosols are considered key factors that contribute to rapid climate warming and ice melt in the Arctic region.However,compared with long-term observations from land-based stations,observational data over the Arctic Ocean remain relatively scarce.Four Arctic scientific expeditions were conducted in the summer and early autumn of 2010,2012,2016,and 2018 via the Chinese research vessel Xue Long,during which the BC concentrations along the routes were measured via light absorption methods.In this work,the spatiotemporal distribution characteristics of BC over the Arctic Ocean were examined on the basis of these observations.The potential sources of BC along the various routes were analyzed via the weighted potential source contribution function and weighted concentrationweighted trajectory methods of the hybrid single-particle Lagrangian integrated trajectory model in conjunction with Arctic transport potential climate model simulations.The analysis results indicated that wildfires in the western Aleutian Islands,Siberia,and Far East regions were the primary contributors to the BC aerosol concentration observed along the Arctic expedition routes in summer,identifying these regions as major potential source areas.展开更多
Aerosol category and its physicochemical properties are key factors influencing its climate and environmental effects.To further enhance our understanding of aerosols in the Himalayas-Tibetan Plateau region,atmospheri...Aerosol category and its physicochemical properties are key factors influencing its climate and environmental effects.To further enhance our understanding of aerosols in the Himalayas-Tibetan Plateau region,atmospheric particulate matter samples were collected at three different altitudes on Mount Qomolangma(Everest).Using an automated scanning electron microscope system,the composition,size,and morphology of 52,349 particles were analyzed.The average mass concentrations of PM_(1),PM_(2.5),and PM_(10)were 0.678,5.054,and 16.698μg/m^(3),respectively.Aluminosilicate particles dominated the samples,accounting for 71.5%to 82.8%of PM_(10)mass and 34.7%to 62.4%of the particle number.Quartz particles,carbonate particles,metal oxides,and sulfates were also observed at different periods.Carbonaceous particles made up a significant portion of aerosols,comprising 2.1%to 9.7%of PM_(10)mass and 10.4%to 45.4%of particle number,with their concentration showing an upward trend with altitude.Small amounts of tar ball particles and fly ash particles were also observed,providing direct evidence of anthropogenic influences on high-altitude regions,even at altitudes exceeding 6000 m.The size distribution and abundance of different particle categories were closely related to the transport trajectories of air masses.The morphology of different particle categories varied,with fly ash particles mainly spherical and carbonaceous particles exhibiting higher irregularity.展开更多
The year,2024,marks the 40th anniversary of Chinese research expeditions in the polar regions and the 25th anniversary of its Arctic research expeditions.China has conducted 14 national Arctic research expeditions.Wit...The year,2024,marks the 40th anniversary of Chinese research expeditions in the polar regions and the 25th anniversary of its Arctic research expeditions.China has conducted 14 national Arctic research expeditions.With the increase of understandings on the global impacts of the changes of Arctic climate system,especially on China’s weather and climate,and demands for commercial utilization of the Arctic sea routes,Chinese scientists have made great progresses on in site and remote sensing observation technologies for Arctic Ocean,interaction mechanisms between atmosphere,sea ice,and ocean,the connection mechanism between the Arctic Ocean and other regions,and have achieved a series of research results.This study summarizes the research achievements by Chinese scientists in the above-mentioned aspects or beyond,identifies knowledge gaps,and based on this,discusses prospects and provides suggestions.From a perspective of observation,improving the observation capabilities of the Arctic Ocean in winter and the ocean under the ice,as well as floe-scale processes of sea ice and mesoscale and submesoscale processes of the ocean,is an urgent task to be addressed.Strengthening international cooperation is necessary for building a monitoring network for the Arctic marine environment.From a perspective of numerical simulation,the descriptive ability and parameterization scheme of sub-grid processes based on observational evidence need to be developed.From a perspective of cross-sphere interactions,in addition to the multi-media coupling within the Arctic Ocean that this review focuses on,the interaction between the Arctic Ocean and land or ice sheet(Greenland),especially the water cycle process,is also a scientific domain that needs to be considered,in the context of Arctic warming and humidification.From a perspective of climate effects,the physical mechanisms that affect the robustness of teleconnection need to be clarified.展开更多
The Atmospheric Infrared Sounder(AIRS)on the Aqua satellite,along with the MWTS/MWHS Synergy(TSHS)sounding system and Atmospheric Vertical Sounder System(VASS)on the Fengyun-3D(FY-3D)satellite,provide highquality data...The Atmospheric Infrared Sounder(AIRS)on the Aqua satellite,along with the MWTS/MWHS Synergy(TSHS)sounding system and Atmospheric Vertical Sounder System(VASS)on the Fengyun-3D(FY-3D)satellite,provide highquality data for studying Arctic temperature change.The generalized cold bias of AIRS is confirmed through horizontal comparisons with Arctic land radiosonde stations.VASS corrects the warm bias of TSHS by incorporating the Hyperspectral Infrared Atmospheric Sounder-I(HIRAS-I).Vertical comparisons demonstrate that AIRS,TSHS,and VASS offer excellent temperature detection from the top of the boundary layer to the lower stratosphere(800–100 h Pa).However,the overestimation and errors of stratospheric temperatures by TSHS and VASS increase with altitude(pressures below60 h Pa).Specifically,the warm bias trends at 0.06 K hPa^(-1),reaching 2.87 K and 2.92 K at 10 h Pa.Similarly,RMSE values trend at 0.05?K h Pa^(-1),reaching 3.62?K and 3.69?K at 10 h Pa.The low correlation(R≥0.65)of TSHS near 250 h Pa in summer is significantly improved in VASS(R≥0.78)after adding HIRAS-I.The high vertical resolution due to infrared hyperspectral resolution facilitates the detection of complex temperature junctions.The retrieval error of AIRS in the boundary layer increases with cloudiness,while VASS combines microwave and infrared channel data to reduce the impact of cloud cover.Assessing the Arctic applicability of these three satellite temperature profile products will facilitate their widespread use in the Arctic region,enhance accurate climate change monitoring,and further reveal the mechanisms of Arctic warming.展开更多
Background CH<sub>4</sub> concentration and seasonal variations measured at Zhongshan Station (69°22'2''S, 76°21'49''E, 18.5 m) in Antarctica from 2008 through 2013 are pr...Background CH<sub>4</sub> concentration and seasonal variations measured at Zhongshan Station (69°22'2''S, 76°21'49''E, 18.5 m) in Antarctica from 2008 through 2013 are presented and discussed. From 2008-2013 CH<sub>4</sub> was measured in weekly<sub> </sub>flask samples and started on line measurement by Picarro CO<sub>2</sub>/CH<sub>4</sub>/H<sub>2</sub>O analyzer from March, 2010-2013. These CH<sub>4</sub> measurements show the expected growth period of CH<sub>4</sub> concentration during February (Antarctic spring) with a peak in September (fall). Irrespective of wind direction, CH<sub>4</sub> concentrations distribute evenly after the removal of polluted air from station operations, accounting for 1% of the data. The mean daily cycle of CH<sub>4</sub> concentration in all four seasons is small. The monthly mean CH<sub>4</sub> concentration at Zhongshan station is similar to those at other stations in Antarctica showing that CH<sub>4</sub> observed in Antarctica is fully mixed in the atmosphere as it is transported from the northern through the southern hemisphere. The annual CH<sub>4</sub> increase in recent years at Zhongshan station is 4.8 ppb·yr<sup>-1</sup>.展开更多
Changes in the form of precipitation have a considerable impact on the Arctic cryosphere and ecological system by influencing the energy balance and surface runoff. In this study, station observations and ERA-Interim ...Changes in the form of precipitation have a considerable impact on the Arctic cryosphere and ecological system by influencing the energy balance and surface runoff. In this study, station observations and ERA-Interim data were used to analyze changes in the rainfall to precipitation ratio（RPR） in northern Canada during the spring–summer season（March–July）from 1979–2015. Our results indicate that ERA-Interim describes the spring–summer variations and trends in temperature and the RPR well. Both the spring–summer mean temperature [0.4℃–1℃（10 yr）^（-1）] and the RPR [2%–6%（10 yr）^（-1）] increased significantly in the Canadian Arctic Archipelago from 1979–2015. Moreover, we suggest that, aside from the contribution of climate warming, the North Atlantic Oscillation is probably another key factor influencing temporal and spatial differences in the RPR over northern Canada.展开更多
Arctic sea ice loss and the associated enhanced warming has been related to midlatitude weather and climate changes through modulate meridional temperature gradients linked to circulation. However, contrasting lines o...Arctic sea ice loss and the associated enhanced warming has been related to midlatitude weather and climate changes through modulate meridional temperature gradients linked to circulation. However, contrasting lines of evidence result in low confidence in the influence of Arctic warming on midlatitude climate. This study examines the additional perspectives that palaeoclimate evidence provides on the decadal relationship between autumn sea ice extent (SIE) in the Barents-Kara (B-K) Seas and extreme cold wave events (ECWEs) in southern China. Reconstruction of the winter Cold Index and SIE in the B-K Seas from 1289 to 2017 shows that a significant anti-phase relationship occurred during most periods of decreasing SIE, indicating that cold winters are more likely in low SIE years due to the “bridge” role of the North Atlantic Oscillation and Siberian High. It is confirmed that the recent increase in ECWEs in southern China is closely related to the sea ice decline in the B-K Seas. However, our results show that the linkage is unstable, especially in high SIE periods, and it is probably modulated by atmospheric internal variability.展开更多
The variation in the precipitation phase in polar regions represents an important indicator of climate change and variability.We studied the precipitation phase at the Great Wall Station and Antarctic Peninsula(AP)reg...The variation in the precipitation phase in polar regions represents an important indicator of climate change and variability.We studied the precipitation phase at the Great Wall Station and Antarctic Peninsula(AP)region,based on daily precipitation,synoptic records and ERA-Interim data during the austral summers of 1985?2014.Overall,there was no trend in the total precipitation amount or days,but the phase of summer precipitation(rainfall days versus snowfall days)showed opposite trends before and after 2001 at the AP.The total summer rain days/snow days increased/decreased during 1985?2001 and significantly decreased at a rate of?14.13 d(10 yr)?1/increased at a rate of 14.31 d(10 yr)?1 during 2001?2014,agreeing well with corresponding variations in the surface air temperature.Further,we found that the longitudinal location of the Amundsen Sea low(ASL)should account for the change in the precipitation phase since 2001,as it has shown a westward drift after 2001[?41.1°(10 yr)?1],leading to stronger cold southerly winds,colder water vapor flux,and more snow over the AP region during summertime.This study points out a supplementary factor for the climate variation on the AP.展开更多
During the recent four decades since 1980,a series of modern climate satellites were launched,allowing for the measurement and record-keeping of multiple climate parameters,especially over the polar regions where trad...During the recent four decades since 1980,a series of modern climate satellites were launched,allowing for the measurement and record-keeping of multiple climate parameters,especially over the polar regions where traditional observations are difficult to obtain.China has been actively engaging in polar expeditions.Many observations were conducted during this period,accompanied by improved Earth climate models,leading to a series of insightful understandings concerning Arctic and Antarctic climate changes.Here,we review the recent progress China has made concerning Arctic and Antarctic climate change research over the past decade.The Arctic temperature increase is much higher than the global-mean warming rate,associated with a rapid decline in sea ice,a phenomenon called the Arctic Amplification.The Antarctic climate changes showed a zonally asymmetric pattern over the past four decades,with most of the fastest changes occurring over West Antarctica and the Antarctic Peninsula.The Arctic and Antarctic climate changes were driven by anthropogenic greenhouse gas emissions and ozone loss,while tropical-polar teleconnections play important roles in driving the regional climate changes and extreme events over the polar regions.Polar climate changes may also feedback to the entire Earth climate system.The adjustment of the circulation in both the troposphere and the stratosphere contributed to the interactions between the polar climate changes and lower latitudes.Climate change has also driven rapid Arctic and Southern ocean acidification.Chinese researchers have made a series of advances in understanding these processes,as reviewed in this paper.展开更多
Extreme cold temperatures were observed in July and August 2023,coinciding with the WINFLY(winter fly-in)period of mid to late August into September 2023,meaning aircraft operations into McMurdo Station and Phoenix Ai...Extreme cold temperatures were observed in July and August 2023,coinciding with the WINFLY(winter fly-in)period of mid to late August into September 2023,meaning aircraft operations into McMurdo Station and Phoenix Airfield were adversely impacted.Specifically,with temperatures below−50℃,safe flight operation was not possible because of the risk of failing hydraulics and fuel turning to gel onboard the aircraft.The cold temperatures were measured across a broad area of the Antarctic,from East Antarctica toward the Ross Ice Shelf,and stretching across West Antarctica to the Antarctic Peninsula.A review of automatic weather station measurements and staffed station observations revealed a series of sites recording new record low temperatures.Four separate cold phases were identified,each a few days in duration and occurring from mid-July to the end of August 2023.A brief analysis of 500-hPa geopotential height anomalies shows how the mid-tropospheric atmospheric environment evolves in relation to these extreme cold temperatures.The monthly 500-hPa geopotential height anomalies show strong negative anomalies in August.Examination of composite geopotential height anomalies during each of the four cold phases suggests various factors leading to cold temperatures,including both southerly off-content flow and calm atmospheric conditions.Understanding the atmospheric environment that leads to such extreme cold temperatures can improve prediction of such events and benefit Antarctic operations and the study of Antarctic meteorology and climatology.展开更多
Data on accumulation and concentration of chemical compounds recorded in an essentially unexplored area(Dome Argus)of the Indian Ocean sector of eastern Antarctica during the past 2,680 years(680 B.C. to 1999 A.D.) ar...Data on accumulation and concentration of chemical compounds recorded in an essentially unexplored area(Dome Argus)of the Indian Ocean sector of eastern Antarctica during the past 2,680 years(680 B.C. to 1999 A.D.) are presented. During the first 1, 700 years(680 B. C. to 1000 A. D.), the accumulation data shows a slightly decreasing trend, while chemical ions appear to be stable, representing a stable climatic condition. An intensive increasing trend of the accumulation occurred during the 12^(th) to 14^(th) century. The period from 15^(th) to 19^(th) century was characterized by a rapid reducing accumulation and concentrations of volatile compounds suffering post-depositional loss linked to sparse precipitation amount,which was temporally consistent with the Little Ice Age(LIA) episode. Comparison between observed accumulation rates with other eastern Antarctic ice cores show a consistent decreasing trend during LIA, while sea salt and dust-originated ions increased due to sea ice extent and intensified atmospheric transportation. Distribution of volcanic originated sulfate over the Antarctic continent show a significant change during the 15^(th) century, coincident with the onset of the LIA. These results are important for the assessment of Antarctic continent mass balance and associated interpretation of the Dome A deep ice core records.展开更多
Long-term,ground-based daily global solar radiation (DGSR) at Zhongshan Station in Antarctica can quantitatively reveal the basic characteristics of Earth’s surface radiation balance and validate satellite data for t...Long-term,ground-based daily global solar radiation (DGSR) at Zhongshan Station in Antarctica can quantitatively reveal the basic characteristics of Earth’s surface radiation balance and validate satellite data for the Antarctic region.The fixed station was established in 1989,and conventional radiation observations started much later in 2008.In this study,a random forest (RF) model for estimating DGSR is developed using ground meteorological observation data,and a highprecision,long-term DGSR dataset is constructed.Then,the trend of DGSR from 1990 to 2019 at Zhongshan Station,Antarctica is analyzed.The RF model,which performs better than other models,shows a desirable performance of DGSR hindcast estimation with an R^2 of 0.984,root-mean-square error of 1.377 MJ m^(-2),and mean absolute error of 0.828 MJ m^(-2).The trend of DGSR annual anomalies increases during 1990–2004 and then begins to decrease after 2004.Note that the maximum value of annual anomalies occurs during approximately 2004/05 and is mainly related to the days with precipitation (especially those related to good weather during the polar day period) at this station.In addition to clouds and water vapor,bad weather conditions (such as snowfall,which can result in low visibility and then decreased sunshine duration and solar radiation) are the other major factors affecting solar radiation at this station.The high-precision,longterm estimated DGSR dataset enables further study and understanding of the role of Antarctica in global climate change and the interactions between snow,ice,and atmosphere.展开更多
The spatiotemporal distribution pattern of marine-origin matter on the Antarctica ice sheet was used to study variations in the source regions, transport mechanisms and postdepositional influences. We present data on ...The spatiotemporal distribution pattern of marine-origin matter on the Antarctica ice sheet was used to study variations in the source regions, transport mechanisms and postdepositional influences. We present data on sea salt ions, sulfur components and stable isotopes from surface and snow pit samples collected along the transect route from Zhongshan Station to Dome A during the austral summer in 2012–2013. A general decreasing trend in the accumulation, sea salt ions and sulfur components occurred with increasing distance from the coast and increasing elevation. However, different sources of the marine components, transport pathways and post-depositional influences were responsible for their different spatial distribution patterns. The marine ions in the coastal snow pit varied seasonally, with higher sea salt ion concentrations in the winter and lower concentrations in the summer; the opposite pattern was found for the sulfur compounds. The sea ice area surrounding Antarctica was the main source region for the deposited sea salt and the open sea water for the sulfur compounds. No significant trends in the marine-origin components were detected during the past 3 decades. Several periods of elevated deposition of sea salt ions were associated with lower temperatures（based on δD and δ18O） or intensified wind fields. In comparison to the sea salt ions, the sulfur concentrations exhibited the opposite distribution patterns and were associated with changes in the surrounding sea ice extent.展开更多
The newly-developed cavity ring-down laser absorption spectroscopy analyzer with special calibration protocols has enabled the direct measurement of atmospheric vapor isotopes at high spatial and temporal resolution. ...The newly-developed cavity ring-down laser absorption spectroscopy analyzer with special calibration protocols has enabled the direct measurement of atmospheric vapor isotopes at high spatial and temporal resolution. This paper presents real-time hydrogen and oxygen stable isotope data for atmospheric water vapor above the sea surface, over a wide range of latitudes spanning from 38°N to 69°S. Our results showed relatively higher values of 8180 and 82H in the subtropical regions than those in the tropical and high latitude regions, and also a notable decreasing trend in the Antarctic coastal region. By combining the hydrogen and oxygen isotope data with meteoric water line and backward trajectory model analysis, we explored the kinetic fractionation caused by subsiding air masses and related saturated vapor pressure in the subtropics, and the evaporation-driven kinetic fractionation in the Antarctic region. Simultaneous observations of meteorological and marine variables were used to interpret the isotopic composition characteristics and influential factors, indicating that d-excess is negatively correlated with humidity across a wide range of latitudes and weather conditions worldwide. Coincident with previous studies, d-excess is also positively correlated with sea surface temperature and air temperature （Tair）, with greater sensitivity to Tair. Thus, atmospheric vapor isotopes measured with high accuracy and good spatial- temporal resolution could act as informative tracers for exploring the water cycle at different regional scales. Such monitoring efforts should be undertaken over a longer time period and in different regions of the world.展开更多
At present,continuous observation data for atmospheric nitrous oxide（N_2O） concentrations are still lacking,especially in east Antarctica.In this paper,nitrous oxide background concentrations were measured at Zhongs...At present,continuous observation data for atmospheric nitrous oxide（N_2O） concentrations are still lacking,especially in east Antarctica.In this paper,nitrous oxide background concentrations were measured at Zhongshan Station（69°22′25″S,76°22′14″E）,east Antarctica during the period of 2008–2012,and their interannual and seasonal characteristics were analyzed and discussed.The mean N_2O concentration was 321.9 n L/L with the range of 320.5–324.8 n L/L during the five years,and it has been increasing at a rate of 0.29% year-1.Atmospheric N_2O concentrations showed a strong seasonal fluctuation during these five years.The concentrations appeared to follow a downtrend from spring to autumn,and then increased in winter.Generally the highest concentrations occurred in spring.This trend was very similar to that observed at other global observation sites.The overall N_2O concentration at the selected global sites showed an increasing annual trend,and the mean N_2O concentration in the Northern Hemisphere was slightly higher than that in the Southern Hemisphere.Our result could be representative of atmospheric N_2O background levels at the global scale.This study provided valuable data for atmospheric N_2O concentrations in east Antarctica,which is important to study on the relationships between N2 O emissions and climate change.展开更多
The background surface O3 concentrations and seasonal changes observed at the Zhongshan Station (69°22'2''S, 76°21'49''E;18.5 m), east Antarctica from 2008 to 2013 are presented. Irre...The background surface O3 concentrations and seasonal changes observed at the Zhongshan Station (69°22'2''S, 76°21'49''E;18.5 m), east Antarctica from 2008 to 2013 are presented. Irrespective of wind direction, surface O3 concentrations distribute evenly after the removal of polluted air from station operations, accounting for 1.1% of the data. These O3 exhibit the expected lowest in summer, with a peak in winter. The daily range of average O3 in all four seasons is small. The monthly mean O3 is similar to that of other stations in Antarctica, with seasonal CO2 amplitudes in the order of 15 ppb to 35 ppb. Surface O3 significantly negatively correlated with UVB in the spring and autumn, with correlation coefficients of 0.50 and 0.57 under the 0.01 significance test. Furthermore, the surface O3 concentration during polar nights was 1 - 2 times higher than that during polar days. Thus, the chemical effect of the aurora lights was the dominant cause of ozone destruction, showing that surface O3 observed in Antarctica has a small interferences from human activities in the atmosphere as it moves from the north through the southern hemisphere.展开更多
The downward shortwave radiation(DSR) is an important part of the Earth's energy balance, driving Earth's system's energy, water, and carbon cycles. Due to the harsh Antarctic environment, the accuracy of ...The downward shortwave radiation(DSR) is an important part of the Earth's energy balance, driving Earth's system's energy, water, and carbon cycles. Due to the harsh Antarctic environment, the accuracy of DSR derived from satellite and reanalysis has not been systematically evaluated over the transect of Zhongshan station to Dome A, East Antarctica.Therefore, this study aims to evaluate DSR reanalysis products(ERA5-Land, ERA5, MERRA-2) and satellite products(CERES and ICDR) in this area. The results indicate that DSR exhibits obvious monthly and seasonal variations, with higher values in summer than in winter. The ERA5-Land(ICDR) DSR product demonstrated the highest(lowest) accuracy,as evidenced by a correlation coefficient of 0.988(0.918), a root-mean-square error of 23.919(69.383) W m^(–2), a mean bias of –1.667(–28.223) W m^(–2) and a mean absolute error of 13.37(58.99) W m^(–2). The RMSE values for the ERA5-Land reanalysis product at seven stations, namely Zhongshan, Panda 100, Panda 300, Panda 400, Taishan, Panda 1100, and Kunlun, were 30.938, 29.447, 34.507, 29.110, 20.339, 17.267, and 14.700 W m^(-2), respectively;with corresponding bias values of 9.887, –12.159, –19.181, –15.519, –8.118, 6.297, and 3.482 W m^(–2). Regarding seasonality, ERA5-Land, ERA5,and MERRA-2 reanalysis products demonstrate higher accuracies during spring and summer, while ICDR products are least accurate in autumn. Cloud cover, water vapor, total ozone, and severe weather are the main factors affecting DSR. The error of DSR products is greatest in coastal areas(particularly at the Zhongshan station) and decreases towards the inland areas of Antarctica.展开更多
The marine hydrological process is still unclear due to scarce observations.Based on stable water isotopes in surface seawater along the 33rd Chinese National Antarctic Science Expedition from November 2016 to April 2...The marine hydrological process is still unclear due to scarce observations.Based on stable water isotopes in surface seawater along the 33rd Chinese National Antarctic Science Expedition from November 2016 to April 2017,this study explored the hydrological processes in the Pacific,Indian and Southern oceans.The results show that the Northwest Pacific(0°–26°N)is a region with strong evaporation(theδ18O-δD slope is 6.58),while the southern Indian Ocean is a region with strong precipitation(theδ18O-δD slope is 9.57).The influence of continental runoff and water mass mixing reduces the correlation betweenδ18O and salinity in the eastern Indian Ocean.The characteristics of the isotopes and hydrological parameters indicate that the Agulhas Front and sub-Tropical Convergence do not merge in the Antarctic–Indian Ocean region.The freezing of sea ice near the Antarctic continent decreases theδ18O andδD by 0.40‰and 7.0‰,respectively,compared with those near 67°S.This study is helpful for understanding marine hydrological processes and promoting the understanding and research of the nature of ocean responses in the context of climate change.展开更多
Recent snow height measurements(2008–15) from nine automatic weather stations(AWSs) on the Ross Ice Shelf are used to examine the synoptic and seasonal variability in snow accumulation,and also to evaluate the perfor...Recent snow height measurements(2008–15) from nine automatic weather stations(AWSs) on the Ross Ice Shelf are used to examine the synoptic and seasonal variability in snow accumulation,and also to evaluate the performance of the Antarctic Mesoscale Prediction System(AMPS) for precipitation. The number of snow accumulation events varies from one station to another between 2008 and 2015,thus demonstrating geographic dependence. The interannual variability in snow accumulation is too high to determine its seasonality based on the current AWS observations with limited time coverage.Comparison between the AMPS and AWS snow height measurements show that approximately 28% of the AWS events are reproduced by AMPS. Furthermore,there are significant correlations between AMPS and AWS coincident event sizes at five stations(p < 0.05). This finding suggests that AMPS has a certain ability to represent actual precipitation events.展开更多
文摘In November 1984,China launched its first expedition to the Southern Ocean and the Antarctic continent,culminating in the establishment of its first year-round research station—Great Wall Station—on the Antarctic Peninsula in February 1985.Forty years later,in February 2024,China’s fifth research station,Qinling Station,commenced operations on Inexpress-ible Island near Terra Nova Bay.
基金supported by the National Natural Science Foundation of China (No.42201151)the Basic Research Fund of the Chinese Academy of Meteorological Sciences (Nos.2023Z004 and 2024Z007)。
文摘Black carbon (BC) aerosols are considered key factors that contribute to rapid climate warming and ice melt in the Arctic region.However,compared with long-term observations from land-based stations,observational data over the Arctic Ocean remain relatively scarce.Four Arctic scientific expeditions were conducted in the summer and early autumn of 2010,2012,2016,and 2018 via the Chinese research vessel Xue Long,during which the BC concentrations along the routes were measured via light absorption methods.In this work,the spatiotemporal distribution characteristics of BC over the Arctic Ocean were examined on the basis of these observations.The potential sources of BC along the various routes were analyzed via the weighted potential source contribution function and weighted concentrationweighted trajectory methods of the hybrid single-particle Lagrangian integrated trajectory model in conjunction with Arctic transport potential climate model simulations.The analysis results indicated that wildfires in the western Aleutian Islands,Siberia,and Far East regions were the primary contributors to the BC aerosol concentration observed along the Arctic expedition routes in summer,identifying these regions as major potential source areas.
基金supported by the Second Tibetan Plateau Scientific Expedition and Research(STEP)program(No.2019QZKK0106)the Basic Research Fund of CAMS(Nos.2023Z004 and 2023Z015).
文摘Aerosol category and its physicochemical properties are key factors influencing its climate and environmental effects.To further enhance our understanding of aerosols in the Himalayas-Tibetan Plateau region,atmospheric particulate matter samples were collected at three different altitudes on Mount Qomolangma(Everest).Using an automated scanning electron microscope system,the composition,size,and morphology of 52,349 particles were analyzed.The average mass concentrations of PM_(1),PM_(2.5),and PM_(10)were 0.678,5.054,and 16.698μg/m^(3),respectively.Aluminosilicate particles dominated the samples,accounting for 71.5%to 82.8%of PM_(10)mass and 34.7%to 62.4%of the particle number.Quartz particles,carbonate particles,metal oxides,and sulfates were also observed at different periods.Carbonaceous particles made up a significant portion of aerosols,comprising 2.1%to 9.7%of PM_(10)mass and 10.4%to 45.4%of particle number,with their concentration showing an upward trend with altitude.Small amounts of tar ball particles and fly ash particles were also observed,providing direct evidence of anthropogenic influences on high-altitude regions,even at altitudes exceeding 6000 m.The size distribution and abundance of different particle categories were closely related to the transport trajectories of air masses.The morphology of different particle categories varied,with fly ash particles mainly spherical and carbonaceous particles exhibiting higher irregularity.
基金The National Natural Science Foundation of China under contract Nos 42325604 and 42276253the Program of Shanghai Academic/Technology Research Leader under contract No.22XD1403600the Fund of the Ministry of Industry and Information Technology of China under contract No.CBG2N21-2-1.
文摘The year,2024,marks the 40th anniversary of Chinese research expeditions in the polar regions and the 25th anniversary of its Arctic research expeditions.China has conducted 14 national Arctic research expeditions.With the increase of understandings on the global impacts of the changes of Arctic climate system,especially on China’s weather and climate,and demands for commercial utilization of the Arctic sea routes,Chinese scientists have made great progresses on in site and remote sensing observation technologies for Arctic Ocean,interaction mechanisms between atmosphere,sea ice,and ocean,the connection mechanism between the Arctic Ocean and other regions,and have achieved a series of research results.This study summarizes the research achievements by Chinese scientists in the above-mentioned aspects or beyond,identifies knowledge gaps,and based on this,discusses prospects and provides suggestions.From a perspective of observation,improving the observation capabilities of the Arctic Ocean in winter and the ocean under the ice,as well as floe-scale processes of sea ice and mesoscale and submesoscale processes of the ocean,is an urgent task to be addressed.Strengthening international cooperation is necessary for building a monitoring network for the Arctic marine environment.From a perspective of numerical simulation,the descriptive ability and parameterization scheme of sub-grid processes based on observational evidence need to be developed.From a perspective of cross-sphere interactions,in addition to the multi-media coupling within the Arctic Ocean that this review focuses on,the interaction between the Arctic Ocean and land or ice sheet(Greenland),especially the water cycle process,is also a scientific domain that needs to be considered,in the context of Arctic warming and humidification.From a perspective of climate effects,the physical mechanisms that affect the robustness of teleconnection need to be clarified.
基金supported by the National Key R&D Program of China(Grant Nos.2022YFC2807204 and 2022YFE0106700)the Basic Research Fund of the Chinese Academy of Meteorological Sciences(Grant Nos.2023Z004,2023Z015,and 2023Y012)。
文摘The Atmospheric Infrared Sounder(AIRS)on the Aqua satellite,along with the MWTS/MWHS Synergy(TSHS)sounding system and Atmospheric Vertical Sounder System(VASS)on the Fengyun-3D(FY-3D)satellite,provide highquality data for studying Arctic temperature change.The generalized cold bias of AIRS is confirmed through horizontal comparisons with Arctic land radiosonde stations.VASS corrects the warm bias of TSHS by incorporating the Hyperspectral Infrared Atmospheric Sounder-I(HIRAS-I).Vertical comparisons demonstrate that AIRS,TSHS,and VASS offer excellent temperature detection from the top of the boundary layer to the lower stratosphere(800–100 h Pa).However,the overestimation and errors of stratospheric temperatures by TSHS and VASS increase with altitude(pressures below60 h Pa).Specifically,the warm bias trends at 0.06 K hPa^(-1),reaching 2.87 K and 2.92 K at 10 h Pa.Similarly,RMSE values trend at 0.05?K h Pa^(-1),reaching 3.62?K and 3.69?K at 10 h Pa.The low correlation(R≥0.65)of TSHS near 250 h Pa in summer is significantly improved in VASS(R≥0.78)after adding HIRAS-I.The high vertical resolution due to infrared hyperspectral resolution facilitates the detection of complex temperature junctions.The retrieval error of AIRS in the boundary layer increases with cloudiness,while VASS combines microwave and infrared channel data to reduce the impact of cloud cover.Assessing the Arctic applicability of these three satellite temperature profile products will facilitate their widespread use in the Arctic region,enhance accurate climate change monitoring,and further reveal the mechanisms of Arctic warming.
文摘Background CH<sub>4</sub> concentration and seasonal variations measured at Zhongshan Station (69°22'2''S, 76°21'49''E, 18.5 m) in Antarctica from 2008 through 2013 are presented and discussed. From 2008-2013 CH<sub>4</sub> was measured in weekly<sub> </sub>flask samples and started on line measurement by Picarro CO<sub>2</sub>/CH<sub>4</sub>/H<sub>2</sub>O analyzer from March, 2010-2013. These CH<sub>4</sub> measurements show the expected growth period of CH<sub>4</sub> concentration during February (Antarctic spring) with a peak in September (fall). Irrespective of wind direction, CH<sub>4</sub> concentrations distribute evenly after the removal of polluted air from station operations, accounting for 1% of the data. The mean daily cycle of CH<sub>4</sub> concentration in all four seasons is small. The monthly mean CH<sub>4</sub> concentration at Zhongshan station is similar to those at other stations in Antarctica showing that CH<sub>4</sub> observed in Antarctica is fully mixed in the atmosphere as it is transported from the northern through the southern hemisphere. The annual CH<sub>4</sub> increase in recent years at Zhongshan station is 4.8 ppb·yr<sup>-1</sup>.
基金supported by the National Key Basic Research Program of China(Grant No.2013CBA01804)the National Science Foundation of China(Grant Nos.41425003 and 41401079)+2 种基金the State Oceanic Administration of the People’s Republic of China Project on Climate in Polar Regions(Grant No.CHINARE2016-2020)the Key Research Program of the Chinese Academy of Sciences(Grant No.KJZD-EW-G03)the Opening Founding of the State Key Laboratory of Cryospheric Sciences(Grant No.SKLCS-OP-2016-03)
文摘Changes in the form of precipitation have a considerable impact on the Arctic cryosphere and ecological system by influencing the energy balance and surface runoff. In this study, station observations and ERA-Interim data were used to analyze changes in the rainfall to precipitation ratio（RPR） in northern Canada during the spring–summer season（March–July）from 1979–2015. Our results indicate that ERA-Interim describes the spring–summer variations and trends in temperature and the RPR well. Both the spring–summer mean temperature [0.4℃–1℃（10 yr）^（-1）] and the RPR [2%–6%（10 yr）^（-1）] increased significantly in the Canadian Arctic Archipelago from 1979–2015. Moreover, we suggest that, aside from the contribution of climate warming, the North Atlantic Oscillation is probably another key factor influencing temporal and spatial differences in the RPR over northern Canada.
基金the National Natural Science Foundation of China(Grant No.42101142)the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDA19070103)the Young Elite Scientists Sponsorship Program by CAST(Grant No.2022QNRC001).
文摘Arctic sea ice loss and the associated enhanced warming has been related to midlatitude weather and climate changes through modulate meridional temperature gradients linked to circulation. However, contrasting lines of evidence result in low confidence in the influence of Arctic warming on midlatitude climate. This study examines the additional perspectives that palaeoclimate evidence provides on the decadal relationship between autumn sea ice extent (SIE) in the Barents-Kara (B-K) Seas and extreme cold wave events (ECWEs) in southern China. Reconstruction of the winter Cold Index and SIE in the B-K Seas from 1289 to 2017 shows that a significant anti-phase relationship occurred during most periods of decreasing SIE, indicating that cold winters are more likely in low SIE years due to the “bridge” role of the North Atlantic Oscillation and Siberian High. It is confirmed that the recent increase in ECWEs in southern China is closely related to the sea ice decline in the B-K Seas. However, our results show that the linkage is unstable, especially in high SIE periods, and it is probably modulated by atmospheric internal variability.
基金Strategic Priority Research Program of Chinese Academy of Sciences(XDA20100300)the National Natural Science Foundation of China(Grant No.41771064)the Basic Fund of the Chinese Academy of Meteorological Sciences(Grant Nos.2018Z001 and 2019Z008).
文摘The variation in the precipitation phase in polar regions represents an important indicator of climate change and variability.We studied the precipitation phase at the Great Wall Station and Antarctic Peninsula(AP)region,based on daily precipitation,synoptic records and ERA-Interim data during the austral summers of 1985?2014.Overall,there was no trend in the total precipitation amount or days,but the phase of summer precipitation(rainfall days versus snowfall days)showed opposite trends before and after 2001 at the AP.The total summer rain days/snow days increased/decreased during 1985?2001 and significantly decreased at a rate of?14.13 d(10 yr)?1/increased at a rate of 14.31 d(10 yr)?1 during 2001?2014,agreeing well with corresponding variations in the surface air temperature.Further,we found that the longitudinal location of the Amundsen Sea low(ASL)should account for the change in the precipitation phase since 2001,as it has shown a westward drift after 2001[?41.1°(10 yr)?1],leading to stronger cold southerly winds,colder water vapor flux,and more snow over the AP region during summertime.This study points out a supplementary factor for the climate variation on the AP.
基金supported by the National Key Research and Development Program of China(2018YFA 0605703)the National Natural Science Foundation of China(No.41976193 and No.42176243)+8 种基金X.CHEN was supported by the National Key Research and Development Program of China(2019YFC1509100)the National Science Foundation of China(No.41825012)B.WU was supported by the Major Program of the National Natural Science Foundation of China(41790472)the National Key Basic Research Project of China(2019YFA0607002)the National Natural Science Foundation of China(41730959)X.CHENG was funded by the Innovation Group Project of Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai)(Grant No.311021008)M.DING was supported by the National Natural Science Foundation of China(42122047 and 42105036)the Basic Research Fund of the Chinese Academy of Meteorological Sciences(2021Y021 and 2021Z006)Q.SUN was supported by the National Key R&D Program of China(No.2022YFE0106300).
文摘During the recent four decades since 1980,a series of modern climate satellites were launched,allowing for the measurement and record-keeping of multiple climate parameters,especially over the polar regions where traditional observations are difficult to obtain.China has been actively engaging in polar expeditions.Many observations were conducted during this period,accompanied by improved Earth climate models,leading to a series of insightful understandings concerning Arctic and Antarctic climate changes.Here,we review the recent progress China has made concerning Arctic and Antarctic climate change research over the past decade.The Arctic temperature increase is much higher than the global-mean warming rate,associated with a rapid decline in sea ice,a phenomenon called the Arctic Amplification.The Antarctic climate changes showed a zonally asymmetric pattern over the past four decades,with most of the fastest changes occurring over West Antarctica and the Antarctic Peninsula.The Arctic and Antarctic climate changes were driven by anthropogenic greenhouse gas emissions and ozone loss,while tropical-polar teleconnections play important roles in driving the regional climate changes and extreme events over the polar regions.Polar climate changes may also feedback to the entire Earth climate system.The adjustment of the circulation in both the troposphere and the stratosphere contributed to the interactions between the polar climate changes and lower latitudes.Climate change has also driven rapid Arctic and Southern ocean acidification.Chinese researchers have made a series of advances in understanding these processes,as reviewed in this paper.
基金support from the US National Science Foundation(Grant Nos.1924730,2301362,and 2205398).
文摘Extreme cold temperatures were observed in July and August 2023,coinciding with the WINFLY(winter fly-in)period of mid to late August into September 2023,meaning aircraft operations into McMurdo Station and Phoenix Airfield were adversely impacted.Specifically,with temperatures below−50℃,safe flight operation was not possible because of the risk of failing hydraulics and fuel turning to gel onboard the aircraft.The cold temperatures were measured across a broad area of the Antarctic,from East Antarctica toward the Ross Ice Shelf,and stretching across West Antarctica to the Antarctic Peninsula.A review of automatic weather station measurements and staffed station observations revealed a series of sites recording new record low temperatures.Four separate cold phases were identified,each a few days in duration and occurring from mid-July to the end of August 2023.A brief analysis of 500-hPa geopotential height anomalies shows how the mid-tropospheric atmospheric environment evolves in relation to these extreme cold temperatures.The monthly 500-hPa geopotential height anomalies show strong negative anomalies in August.Examination of composite geopotential height anomalies during each of the four cold phases suggests various factors leading to cold temperatures,including both southerly off-content flow and calm atmospheric conditions.Understanding the atmospheric environment that leads to such extreme cold temperatures can improve prediction of such events and benefit Antarctic operations and the study of Antarctic meteorology and climatology.
基金financially supported by the National Natural Science Foundation of China (41671063, 41425003, 41476164, 41671073, and 41721091)Supporting funds also include that from the State Oceanic Administration, the Youth Innovation Promotion Association, NIEER, and the State Key Laboratory of the Cryospheric Science
文摘Data on accumulation and concentration of chemical compounds recorded in an essentially unexplored area(Dome Argus)of the Indian Ocean sector of eastern Antarctica during the past 2,680 years(680 B.C. to 1999 A.D.) are presented. During the first 1, 700 years(680 B. C. to 1000 A. D.), the accumulation data shows a slightly decreasing trend, while chemical ions appear to be stable, representing a stable climatic condition. An intensive increasing trend of the accumulation occurred during the 12^(th) to 14^(th) century. The period from 15^(th) to 19^(th) century was characterized by a rapid reducing accumulation and concentrations of volatile compounds suffering post-depositional loss linked to sparse precipitation amount,which was temporally consistent with the Little Ice Age(LIA) episode. Comparison between observed accumulation rates with other eastern Antarctic ice cores show a consistent decreasing trend during LIA, while sea salt and dust-originated ions increased due to sea ice extent and intensified atmospheric transportation. Distribution of volcanic originated sulfate over the Antarctic continent show a significant change during the 15^(th) century, coincident with the onset of the LIA. These results are important for the assessment of Antarctic continent mass balance and associated interpretation of the Dome A deep ice core records.
基金supported by the National Natural Science Foundation of China (Grant Nos.41941010,41771064 and 41776195)the National Basic Research Program of China (Grant No.2016YFC1400303)the Basic Fund of the Chinese Academy of Meteorological Sciences (Grant No.2018Z001)。
文摘Long-term,ground-based daily global solar radiation (DGSR) at Zhongshan Station in Antarctica can quantitatively reveal the basic characteristics of Earth’s surface radiation balance and validate satellite data for the Antarctic region.The fixed station was established in 1989,and conventional radiation observations started much later in 2008.In this study,a random forest (RF) model for estimating DGSR is developed using ground meteorological observation data,and a highprecision,long-term DGSR dataset is constructed.Then,the trend of DGSR from 1990 to 2019 at Zhongshan Station,Antarctica is analyzed.The RF model,which performs better than other models,shows a desirable performance of DGSR hindcast estimation with an R^2 of 0.984,root-mean-square error of 1.377 MJ m^(-2),and mean absolute error of 0.828 MJ m^(-2).The trend of DGSR annual anomalies increases during 1990–2004 and then begins to decrease after 2004.Note that the maximum value of annual anomalies occurs during approximately 2004/05 and is mainly related to the days with precipitation (especially those related to good weather during the polar day period) at this station.In addition to clouds and water vapor,bad weather conditions (such as snowfall,which can result in low visibility and then decreased sunshine duration and solar radiation) are the other major factors affecting solar radiation at this station.The high-precision,longterm estimated DGSR dataset enables further study and understanding of the role of Antarctica in global climate change and the interactions between snow,ice,and atmosphere.
基金financially supported by the Innovative Research Group,the National Natural Science Foundation of China(No.41121001)the National Basic Research Program of China(973 Program,No.2013CBA01804)+3 种基金the State Key Laboratory of Cryospheric Sciences supporting fund(No.SKLCS-ZZ-2015-01)the National Natural Science Foundation of China(Nos.41201069,41476164)the State Oceanic Administration of People's Republic of China Project on Climate in Polar Regions(Nos.CHINARE 2015-04-04 and CHINARE 2015-02-02)the Foundation for Excellent Youth Scholars of Cold and Arid Regions Environmental and Engineering Research Institute,Chinese Academy of Sciences(CAREERI,CAS)
文摘The spatiotemporal distribution pattern of marine-origin matter on the Antarctica ice sheet was used to study variations in the source regions, transport mechanisms and postdepositional influences. We present data on sea salt ions, sulfur components and stable isotopes from surface and snow pit samples collected along the transect route from Zhongshan Station to Dome A during the austral summer in 2012–2013. A general decreasing trend in the accumulation, sea salt ions and sulfur components occurred with increasing distance from the coast and increasing elevation. However, different sources of the marine components, transport pathways and post-depositional influences were responsible for their different spatial distribution patterns. The marine ions in the coastal snow pit varied seasonally, with higher sea salt ion concentrations in the winter and lower concentrations in the summer; the opposite pattern was found for the sulfur compounds. The sea ice area surrounding Antarctica was the main source region for the deposited sea salt and the open sea water for the sulfur compounds. No significant trends in the marine-origin components were detected during the past 3 decades. Several periods of elevated deposition of sea salt ions were associated with lower temperatures（based on δD and δ18O） or intensified wind fields. In comparison to the sea salt ions, the sulfur concentrations exhibited the opposite distribution patterns and were associated with changes in the surrounding sea ice extent.
基金funded by the National Giant Scientific Research Project (No. 2013CBA01804)the State Oceanic Administration Project of the People's Republic of China on Climate in Polar Regions (No. 201203015)
文摘The newly-developed cavity ring-down laser absorption spectroscopy analyzer with special calibration protocols has enabled the direct measurement of atmospheric vapor isotopes at high spatial and temporal resolution. This paper presents real-time hydrogen and oxygen stable isotope data for atmospheric water vapor above the sea surface, over a wide range of latitudes spanning from 38°N to 69°S. Our results showed relatively higher values of 8180 and 82H in the subtropical regions than those in the tropical and high latitude regions, and also a notable decreasing trend in the Antarctic coastal region. By combining the hydrogen and oxygen isotope data with meteoric water line and backward trajectory model analysis, we explored the kinetic fractionation caused by subsiding air masses and related saturated vapor pressure in the subtropics, and the evaporation-driven kinetic fractionation in the Antarctic region. Simultaneous observations of meteorological and marine variables were used to interpret the isotopic composition characteristics and influential factors, indicating that d-excess is negatively correlated with humidity across a wide range of latitudes and weather conditions worldwide. Coincident with previous studies, d-excess is also positively correlated with sea surface temperature and air temperature （Tair）, with greater sensitivity to Tair. Thus, atmospheric vapor isotopes measured with high accuracy and good spatial- temporal resolution could act as informative tracers for exploring the water cycle at different regional scales. Such monitoring efforts should be undertaken over a longer time period and in different regions of the world.
基金supported by the Program of China Polar Environment Investigation and Assessment (No.CHINARE 2011–2015)the National Natural Science Foundation of China (Nos.41176171,41576181)
文摘At present,continuous observation data for atmospheric nitrous oxide（N_2O） concentrations are still lacking,especially in east Antarctica.In this paper,nitrous oxide background concentrations were measured at Zhongshan Station（69°22′25″S,76°22′14″E）,east Antarctica during the period of 2008–2012,and their interannual and seasonal characteristics were analyzed and discussed.The mean N_2O concentration was 321.9 n L/L with the range of 320.5–324.8 n L/L during the five years,and it has been increasing at a rate of 0.29% year-1.Atmospheric N_2O concentrations showed a strong seasonal fluctuation during these five years.The concentrations appeared to follow a downtrend from spring to autumn,and then increased in winter.Generally the highest concentrations occurred in spring.This trend was very similar to that observed at other global observation sites.The overall N_2O concentration at the selected global sites showed an increasing annual trend,and the mean N_2O concentration in the Northern Hemisphere was slightly higher than that in the Southern Hemisphere.Our result could be representative of atmospheric N_2O background levels at the global scale.This study provided valuable data for atmospheric N_2O concentrations in east Antarctica,which is important to study on the relationships between N2 O emissions and climate change.
文摘The background surface O3 concentrations and seasonal changes observed at the Zhongshan Station (69°22'2''S, 76°21'49''E;18.5 m), east Antarctica from 2008 to 2013 are presented. Irrespective of wind direction, surface O3 concentrations distribute evenly after the removal of polluted air from station operations, accounting for 1.1% of the data. These O3 exhibit the expected lowest in summer, with a peak in winter. The daily range of average O3 in all four seasons is small. The monthly mean O3 is similar to that of other stations in Antarctica, with seasonal CO2 amplitudes in the order of 15 ppb to 35 ppb. Surface O3 significantly negatively correlated with UVB in the spring and autumn, with correlation coefficients of 0.50 and 0.57 under the 0.01 significance test. Furthermore, the surface O3 concentration during polar nights was 1 - 2 times higher than that during polar days. Thus, the chemical effect of the aurora lights was the dominant cause of ozone destruction, showing that surface O3 observed in Antarctica has a small interferences from human activities in the atmosphere as it moves from the north through the southern hemisphere.
基金supported by the National Natural Science Foundation of China (Grants Nos.42122047 and 42306270)the Basic Research Fund of the Chinese Academy of Meteorological Sciences (Grant Nos.2021Z006 and 2023Z013)。
文摘The downward shortwave radiation(DSR) is an important part of the Earth's energy balance, driving Earth's system's energy, water, and carbon cycles. Due to the harsh Antarctic environment, the accuracy of DSR derived from satellite and reanalysis has not been systematically evaluated over the transect of Zhongshan station to Dome A, East Antarctica.Therefore, this study aims to evaluate DSR reanalysis products(ERA5-Land, ERA5, MERRA-2) and satellite products(CERES and ICDR) in this area. The results indicate that DSR exhibits obvious monthly and seasonal variations, with higher values in summer than in winter. The ERA5-Land(ICDR) DSR product demonstrated the highest(lowest) accuracy,as evidenced by a correlation coefficient of 0.988(0.918), a root-mean-square error of 23.919(69.383) W m^(–2), a mean bias of –1.667(–28.223) W m^(–2) and a mean absolute error of 13.37(58.99) W m^(–2). The RMSE values for the ERA5-Land reanalysis product at seven stations, namely Zhongshan, Panda 100, Panda 300, Panda 400, Taishan, Panda 1100, and Kunlun, were 30.938, 29.447, 34.507, 29.110, 20.339, 17.267, and 14.700 W m^(-2), respectively;with corresponding bias values of 9.887, –12.159, –19.181, –15.519, –8.118, 6.297, and 3.482 W m^(–2). Regarding seasonality, ERA5-Land, ERA5,and MERRA-2 reanalysis products demonstrate higher accuracies during spring and summer, while ICDR products are least accurate in autumn. Cloud cover, water vapor, total ozone, and severe weather are the main factors affecting DSR. The error of DSR products is greatest in coastal areas(particularly at the Zhongshan station) and decreases towards the inland areas of Antarctica.
基金The National Natural Science Foundation of China under contract No.42122047the Basic Research Fund of Chinese Academy of Meteorological Sciences under contract Nos 2021Z006,2023Z015 and 2023Z005the Chinese National Antarctic Science Expedition.
文摘The marine hydrological process is still unclear due to scarce observations.Based on stable water isotopes in surface seawater along the 33rd Chinese National Antarctic Science Expedition from November 2016 to April 2017,this study explored the hydrological processes in the Pacific,Indian and Southern oceans.The results show that the Northwest Pacific(0°–26°N)is a region with strong evaporation(theδ18O-δD slope is 6.58),while the southern Indian Ocean is a region with strong precipitation(theδ18O-δD slope is 9.57).The influence of continental runoff and water mass mixing reduces the correlation betweenδ18O and salinity in the eastern Indian Ocean.The characteristics of the isotopes and hydrological parameters indicate that the Agulhas Front and sub-Tropical Convergence do not merge in the Antarctic–Indian Ocean region.The freezing of sea ice near the Antarctic continent decreases theδ18O andδD by 0.40‰and 7.0‰,respectively,compared with those near 67°S.This study is helpful for understanding marine hydrological processes and promoting the understanding and research of the nature of ocean responses in the context of climate change.
基金funded by the National Key Basic Research Program of China (Grant No.2013CBA01804)the Natural Science Foundation of China (Grant Nos.41206175 and 41576182)the Scientific Research Foundation for the Introduction of Talent by Shandong Normal University
文摘Recent snow height measurements(2008–15) from nine automatic weather stations(AWSs) on the Ross Ice Shelf are used to examine the synoptic and seasonal variability in snow accumulation,and also to evaluate the performance of the Antarctic Mesoscale Prediction System(AMPS) for precipitation. The number of snow accumulation events varies from one station to another between 2008 and 2015,thus demonstrating geographic dependence. The interannual variability in snow accumulation is too high to determine its seasonality based on the current AWS observations with limited time coverage.Comparison between the AMPS and AWS snow height measurements show that approximately 28% of the AWS events are reproduced by AMPS. Furthermore,there are significant correlations between AMPS and AWS coincident event sizes at five stations(p < 0.05). This finding suggests that AMPS has a certain ability to represent actual precipitation events.
