This study investigates the relationship between atmospheric stratification (i.e., static stability given by N^(2)) and the vertical energy transfer of stationary planetary waves, and further illustrates the underlyin...This study investigates the relationship between atmospheric stratification (i.e., static stability given by N^(2)) and the vertical energy transfer of stationary planetary waves, and further illustrates the underlying physical mechanism. Specifically, for the simplified case of constant stratospheric N^(2), the refractive index square of planetary waves has a theoretical tendency to increase first and then decrease with an increased N^(2), whereas the group velocity weakens. Mechanistically, this behavior can be understood as an intensified suppression of vertical isentropic surface displacement caused by meridional heat transport of planetary waves under strong N^(2) conditions. Observational analysis corroborates this finding, demonstrating a reduction in the vertical-propagation velocity of waves with increased N^(2). A linear, quasi- geostrophic, mid-latitude beta-plane model with a constant background westerly wind and a prescribed N^(2) applicable to the stratosphere is used to obtain analytic solutions. In this model, the planetary waves are initiated by steady energy influx from the lower boundary. The analysis indicates that under strong N^(2) conditions, the amplitude of planetary waves can be sufficiently increased by the effective energy convergence due to the slowing vertical energy transfer, resulting in a streamfunction response in this model that contains more energy. For N^(2) with a quasi-linear vertical variation, the results bear a resemblance to the constant case, except that the wave amplitude and oscillating frequency show some vertical variations.展开更多
Climate models are essential for understanding past,present,and future changes in atmospheric circulation,with circulation modes providing key sources of seasonal predictability and prediction uncertainties for both g...Climate models are essential for understanding past,present,and future changes in atmospheric circulation,with circulation modes providing key sources of seasonal predictability and prediction uncertainties for both global and regional climates.This study assesses the performance of models participating in phase 6 of the Coupled Model Intercomparison Project in simulating interannual variability modes of Northern Hemisphere 500-hPa geopotential height during winter and summer,distinguishing predictable(potentially predictable on seasonal or longer timescales)and unpredictable(intraseasonal and essentially unpredictable at long range)components,using reanalysis data and a variance decomposition method.Although most models effectively capture unpredictable modes in reanalysis,their ability to reproduce dominant predictable modes-specifically the Pacific-North American pattern,Arctic Oscillation,and Western Pacific Oscillation in winter,and the East Atlantic and North Atlantic Oscillations in summer-varies notably.An optimal ensemble is identified to distinguish(a)predictable-external modes,dominated by external forcing,and(b)predictable-internal modes,associated with slow internal variability,during the historical period(1950-2014)and the SSP5-8.5 scenario(2036-2100).Under increased radiative forcing,the leading winter/summer predictable-external mode exhibits a more uniform spatial distribution,remarkably larger trend and annual variance,and enhanced height-sea surface temperature(SST)covariance under SSP5-8.5 compared to historical conditions.The dominant winter/summer predictable-internal modes also exhibit increased variance and height-SST covariance under SSP5-8.5,along with localized changes in spatial configuration.Minimal changes are observed in spatial distribution or variance for dominant winter/summer unpredictable modes under SSP5-8.5.This study,from a predictive perspective,deepens our understanding of model uncertainties and projected changes in circulations.展开更多
The year 2024 marked the 40th anniversary of Advances in Atmospheric Sciences(AAS),as well as the centenary of the Chinese Meteorological Society(CMS).The inaugural issue of AAS was published in 1984,initially being s...The year 2024 marked the 40th anniversary of Advances in Atmospheric Sciences(AAS),as well as the centenary of the Chinese Meteorological Society(CMS).The inaugural issue of AAS was published in 1984,initially being sponsored primarily by Chinese National Committee for the International Association of Meteorological and Atmospheric Sciences(IAMAS)and the Institute of Atmospheric Physics at the Chinese Academy of Sciences.In 2006,Springer became AAS’s international publisher.Then,in 2015,the CMS joined in sponsoring AAS,and in the same year,AAS also became an affiliated journal of the IAMAS.These milestone events helped broaden the reach of AAS,culminating in the journal establishing itself as a truly international journal supporting the advancement of the atmospheric sciences.展开更多
Atmospheric turbulence is an important parameter affecting laser atmospheric transmission.This paper reports on a self-developed atmospheric turbulence detection Li DAR system(scanning differential image motion Li DAR...Atmospheric turbulence is an important parameter affecting laser atmospheric transmission.This paper reports on a self-developed atmospheric turbulence detection Li DAR system(scanning differential image motion Li DAR(DIM-Li DAR)system).By designing and simulating the optical system of atmospheric turbulence detection Li DAR,the basic optical imaging accuracy has been determined.展开更多
A nonlinear multi-scale interaction(NMI)model was proposed and developed by the first author for nearly 30 years to represent the evolution of atmospheric blocking.In this review paper,we first review the creation and...A nonlinear multi-scale interaction(NMI)model was proposed and developed by the first author for nearly 30 years to represent the evolution of atmospheric blocking.In this review paper,we first review the creation and development of the NMI model and then emphasize that the NMI model represents a new tool for identifying the basic physics of how climate change influences mid-to-high latitude weather extremes.The building of the NMI model took place over three main periods.In the 1990s,a nonlinear Schr?dinger(NLS)equation model was presented to describe atmospheric blocking as a wave packet;however,it could not depict the lifetime(10-20 days)of atmospheric blocking.In the 2000s,we proposed an NMI model of atmospheric blocking in a uniform basic flow by making a scale-separation assumption and deriving an eddyforced NLS equation.This model succeeded in describing the life cycle of atmospheric blocking.In the 2020s,the NMI model was extended to include the impact of a changing climate mainly by altering the basic zonal winds and the magnitude of the meridional background potential vorticity gradient(PVy).Model results show that when PVy is smaller,blocking has a weaker dispersion and a stronger nonlinearity,so blocking can be more persistent and have a larger zonal scale and weaker eastward movement,thus favoring stronger weather extremes.However,when PVy is much smaller and below a critical threshold under much stronger winter Arctic warming of global warming,atmospheric blocking becomes locally less persistent and shows a much stronger westward movement,which acts to inhibit local cold extremes.Such a case does not happen in summer under global warming because PVy fails to fall below the critical threshold.Thus,our theory indicates that global warming can render summer-blocking anticyclones and mid-to-high latitude heatwaves more persistent,intense,and widespread.展开更多
Restoration of phase aberrations is crucial for addressing atmospheric turbulence in light propagation.Traditional restoration algorithms based on Zernike polynomials(ZPs)often encounter challenges related to high com...Restoration of phase aberrations is crucial for addressing atmospheric turbulence in light propagation.Traditional restoration algorithms based on Zernike polynomials(ZPs)often encounter challenges related to high computational complexity and insufficient capture of high-frequency phase aberration components,so we proposed a Principal-Component-Analysis-based method for representing phase aberrations.This paper discusses the factors influencing the accuracy of restoration,mainly including the sample space size and the sampling interval of D/r_(0),on the basis of characterizing phase aberrations by Principal Components(PCs).The experimental results show that a larger D/r_(0)sampling interval can ensure the generalization ability and robustness of the principal components in the case of a limited amount of original data,which can help to achieve high-precision deployment of the model in practical applications quickly.In the environment with relatively strong turbulence in the test set of D/r_(0)=24,the use of 34 terms of PCs can improve the corrected Strehl ratio(SR)from 0.007 to 0.1585,while the Strehl ratio of the light spot after restoration using 34 terms of ZPs is only 0.0215,demonstrating almost no correction effect.The results indicate that PCs can serve as a better alternative in representing and restoring the characteristics of atmospheric turbulence induced phase aberrations.These findings pave the way to use PCs of phase aberrations with fewer terms than traditional ZPs to achieve data dimensionality reduction,and offer a reference to accelerate and stabilize the model and deep learning based adaptive optics correction.展开更多
Subseasonal-to-seasonal(S2S)forecasting for East Asian atmospheric circulation poses significant challenges for conventional numerical weather prediction(NWP)models.Recently,deep learning(DL)models have demonstrated s...Subseasonal-to-seasonal(S2S)forecasting for East Asian atmospheric circulation poses significant challenges for conventional numerical weather prediction(NWP)models.Recently,deep learning(DL)models have demonstrated significant potential in further enhancing S2S forecasts beyond the capabilities of NWP models.However,most current DLbased S2S forecasting models largely overlook the role of global predictors from multiple spheres,such as ocean,land,and atmosphere domains,that are crucial for effective S2S forecasting.In this study,we introduce EAAC-S2S,a tailored DL model for S2S forecasting of East Asian atmospheric circulation.EAAC-S2S employs the cross-attention mechanism to couple atmospheric circulations over East Asia with representative multi-sphere(i.e.,atmosphere,land,and ocean)variables,providing pentad-averaged circulation forecasts up to 12 pentads ahead throughout all seasons.Experimental results demonstrate,on the S2S time scale,that EAAC-S2S consistently outperforms the European Centre for MediumRange Weather Forecasts(ECMWF)Ensemble Prediction System by decreasing the root-mean-square error(RMSE)by3.8%and increasing the anomaly correlation coefficient(ACC)by 8.6%,averaged across all 17 predictands.Our system also shows good skill for examples of heatwaves and the South China Sea Subtropical High Intensity Index(SCSSHII).Moreover,quantitative interpretability analysis including multi-sphere attribution and attention visualization are conducted for the first time in a DL S2S model,where the traced predictability aligns well with prior meteorological knowledge.We hope that our results have the potential to advance research in data-driven S2S forecasting.展开更多
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
China is the largest emitter of anthropogenic CO_(2) globally,with its cities recognized as significant emission hotspots.Consequently,evaluating anthropogenic CO_(2) emissions and the carbon neutral capability(CNC)of...China is the largest emitter of anthropogenic CO_(2) globally,with its cities recognized as significant emission hotspots.Consequently,evaluating anthropogenic CO_(2) emissions and the carbon neutral capability(CNC)of Chinese cities is critical for climate change mitigation.Despite this importance,no studies to date have assessed recent and future city-scale CNCs using the top-down atmospheric inversion approach,revealing substantial knowledge gaps regarding regional CO_(2) budgets.To address these issues,this research focused on Hangzhou,a megacity known for having the highest forest cover among China’s provincial capitals,as study region.Year-round atmospheric CO_(2) concentration measurements were conducted from December 2020 to November 2021 at two sites:one urban and one suburban.These observations,along with their difference,were utilized to derive city-scale posterior anthropogenic CO_(2) emissions and to evaluate recent and future CNCs.Our key findings are as follows:(1)The manufacturing industry,energy industry and oil refineries/transformation industry were identified as the largest contributors to urban-suburban CO_(2) difference,accounting for 36.5%,21.3%,and 16.6%,respectively.Additionally,82.5%,65.2%,81.2%and 86.3%of total anthropogenic CO_(2) enhancements were attributed to emissions within Hangzhou city in winter,spring,summer and autumn,respectively.(2)The posterior annual anthropogenic CO_(2) emission for Hangzhouwas estimated at 4.65(±0.72)×10^(10) kg/a,indicating significant biases among different prior CO_(2) emission inventories.The annual biological CO_(2) sink,derived from multiple products,was estimated at-0.48(±0.16)×10^(10) kg.(3)The calculated CNC for 2021was 10.3%±3.4%,highlighting a substantial gap towards achieving full carbon neutrality.Considering potential increases in ecosystem carbon sinks due to forest age and uncertainties from climate change,it was predicted that at least 65.2%-82.6%of anthropogenic CO_(2) emissions must be reduced to achieve the goal of full carbon neutrality by year of 2060.展开更多
Atmospheric de-aliasing is one of the most important background models for recovering Earth's temporal gravity field from gravity satellite missions.To meet the needs of China's gravimetric satellite platform,...Atmospheric de-aliasing is one of the most important background models for recovering Earth's temporal gravity field from gravity satellite missions.To meet the needs of China's gravimetric satellite platform,an independent atmospheric dealiasing model that relies on Chinese meteorological data needs to be developed.The release of CRA-40,as the firstgeneration Chinese atmospheric reanalysis,provides the opportunity.This study proposes a revised modeling method to calibrate CRA-40 and develops a new atmospheric de-aliasing model(HUST-CRA,2002-20).Intensive assessments are made between HUST-CRA and the latest official de-aliasing product of the international gravity satellite mission.The tidal components of the two products demonstrate high consistency,e.g.,the spatial correlation for the major tide S_1 is 0.96.The non-tidal components of the two products are also equivalent:(1)the temporal correlation of low-degree terms is higher than 0.97,except for the term of S22(0.93);(2)the spectral correlation of degree geoid height up to degree/order 100 is as high as 0.99;(3)the confidence interval of the spatial correlation(2002-20)is[0.971,0.995]at a confidence level of 95%;and(4)the difference in KBRR(K-band range rate)residuals is less than 0.08μm s^(-1),the difference in the derived temporal gravity field is less than 0.32 mm in terms of geoid height,and both are apparently beyond the ability of the current gravity satellite mission.This confirms that CRA-40 is of high quality and that the derived de-aliasing product,HUST-CRA,is accurate enough to be used in both Chinese and international gravity satellite missions.展开更多
Ice cores play an important role in the reconstruction of historical atmospheric information.The glacier of the Tibetan Plateau is influenced by the Indian monsoon and westerly winds,which divide the Tibetan Plateau i...Ice cores play an important role in the reconstruction of historical atmospheric information.The glacier of the Tibetan Plateau is influenced by the Indian monsoon and westerly winds,which divide the Tibetan Plateau into monsoon-and westly influenced regions.These atmospheric circulations bring distinct microbial communities to glaciers,with the microbial dispersal process being also influenced by atmospheric factors.However,the potential influence of between bacterial abundance and atmospheric factors is not well known.To reveal potential mechanisms controlling bacterial abundance between two regions,we obtained bacterial abundance and atmospheric records for the past 46 years from two ice cores located within these regions.Statistical regression models were constructed to fit the relationship between bacterial abundance and atmospheric factors.Generalized additive model(GAM)was superior in modeling bacterial abundance compared with linear models and showed that the key factors affecting bacterial abundance were different in the monsoon-and westerly-dominated regions.Specifically,atmospheric dust and black carbon were the key factors for the monsoon-dominated region,and westerly index was the key factor for the westerly-dominated region.The model outputs confirm that atmospheric black carbon plays an important role in affecting bacterial abundance for the glacier located within the monsoon-dominated region,particularly in recent decades.The model also predicted that bacterial abundance will increase by 27%with a doubled black carbon deposition.We quantify and model for the first time that relationship between bacterial abundance and atmospheric black carbon in Tibetan glaciers change over time based on GAM models.展开更多
Although atmospheric CO_(2) observations are becoming increasingly widespread in China,the identification of CO_(2) emission sources is still scarce,especially in undeveloped Central China.To effectively address this ...Although atmospheric CO_(2) observations are becoming increasingly widespread in China,the identification of CO_(2) emission sources is still scarce,especially in undeveloped Central China.To effectively address this issue,in a typical site in Central China,the simultaneous measurements of atmospheric CO_(2),CO,andδ^(13)C were conducted,and the characteristics of CO_(2) emission sources were systematically investigated based on the relationships among CO_(2),CO,andδ^(13)C.The average CO_(2)/CO ratio of winter increased from 52.4 ppm/ppm during 2018–2020 to 65.1 ppm/ppm during 2021–2022,which confirmed the improvement of energy consumption efficiency in China.Air-mass transportation from central China and Yangtze River Delta regions contributed largely to higher CO_(2)/CO ratios in 2021–2022.A highermean CO_(2)/CO ratio appeared during the morning rush hours(60.3 ppm/ppm)than in the afternoon rush hours(51.4 ppm/ppm)in winter.In addition,the meanδ^(13)C value of CO_(2) sources(δ^(13)Cs)also displayed more negative values during the morning rush hours(-28.3‰)than the afternoon rush hours(-22.2‰),suggesting the significant influence of vehicle and natural gas usage at themorning rush hours and the impact of straw burning in the afternoon rush hours.The meanδ^(13)Cs was-24.7‰for winter and-21.9‰for vegetation season,implying the main contribution of coal in winter and the impact of C4 plants during the vegetation season.The contribution of biogenic respiration CO_(2) was inferred to exceed 50%during the nighttime of summer according to the obtained meanδ^(13)C value of biogenic respiration CO_(2),which was calculated to be-21.4‰.展开更多
Although the Chinese new-generation Fengyun-4B(FY-4B) geostationary satellite Atmospheric Motion Vector(AMV) products became operational in June 2022, their accuracy and utility remain largely unexamined. This study c...Although the Chinese new-generation Fengyun-4B(FY-4B) geostationary satellite Atmospheric Motion Vector(AMV) products became operational in June 2022, their accuracy and utility remain largely unexamined. This study comprehensively evaluates FY-4B AMV products for August and October 2023, as well as January and April 2024,exploring their application in monitoring the South China Sea Summer Monsoon(SCSSM) onset. The results indicate that AMV products derived from the upper-level water vapor absorption channel(AMV_WV) and the infrared channel(AMV_IR) demonstrate high accuracy when compared with ERA5 reanalysis data. The root mean square error(RMSE) is mostly between 4.5 m s^(–1)and 6.4 m s^(–1), with coefficients of determination(R2) values ranging from 0.7 to 0.8, indicating the overall reliability of FY-4B AMVs. The observation errors of AMVs exhibit significant vertical structure characteristics. Specifically, the AMV_WV products demonstrate superior accuracy above 350 h Pa, while the AMV_IR products exhibit reduced errors in the layers between 200–500 h Pa and 700–950 h Pa. Spatially, most areas exhibit low observation errors for AMVs, while clear-sky weather and deep convective cloud systems can increase errors. A lack of clouds or water vapor may reduce the number of observation samples in some areas, leading to unstable RMSE performance, which is particularly evident for AMV_WV RMSE around 25°–30°N in January and near 25°S in August. Deep convective cloud systems can influence AMV retrieval results, leading to systematic observation errors, especially for the infrared channel.Additionally, AMV_WV is more reliable during the daytime, with a lower RMSE compared to nighttime, while AMV_IR exhibits a diverging diurnal variation pattern. Finally, the FY-4B AMV_WV products were applied to monitor the SCSSM event in 2024. Significant zonal wind direction reversal characteristics were observed in key regions around the onset date,indicating that AMVs can serve as effective indicators for monitoring the SCSSM onset.展开更多
Marine biological activity has long been recognized to impact the atmospheric chemistry of coastal areas.In this work,we monitored the seasonal variation of carbonyl compounds in the coastal city of Qingdao,located in...Marine biological activity has long been recognized to impact the atmospheric chemistry of coastal areas.In this work,we monitored the seasonal variation of carbonyl compounds in the coastal city of Qingdao,located in the north of China’s coastline and the south of Jiaodong Peninsula,with the vast hinterland in the west.The mean total concentration of the 15 carbonyls varied significantly between seasons,with the highest observed in autumn(10.2±6.2 ppbv),followed by spring(9.0±3.0 ppbv),winter(6.4±4.0 ppbv)and summer(3.4±1.4 ppbv).Using bivariate analysis,the agricultural emissions from inland areas were responsible for the high levels of carbonyls in the autumn.In summer,clean and humid sea winds helped reduce the concentration of carbonyls,but they also brought air masses from vegetation,and marine organisms,which contributed to high levels of carbonyls in the spring of coastal areas.The observation-based chemistry box model found that the forma-tion of formaldehyde and acetaldehyde was primarily controlled by the RO+O2 reaction,and alkenes oxidation was the main contributing factor.Based on the OH radical loss rate(LOH)and ozone formation potential(OFP)calculation,we found that autumn and spring seasons have significantly higher values of LOH and OFP than winter and summer due to the presence of high concentrations of carbonyl compounds.Therefore,it is believed that these carbonyl compounds primarily originate from agricultural activities,and marine air influences the atmospheric chemistry of the coastal areas.展开更多
Accurate monitoring of the atmospheric environment and its evolution are important for understanding the sources,chemical mechanisms,and transport processes of air pollution and carbon emissions in China,and for regul...Accurate monitoring of the atmospheric environment and its evolution are important for understanding the sources,chemical mechanisms,and transport processes of air pollution and carbon emissions in China,and for regulatory and control purposes.This study gives an overview of atmospheric environment monitoring technology and equipment in China and summarizes the major achievements obtained in recent years.China has made great progress in the development of atmospheric environment monitoring technology and equipment with decades of effort.The manufacturing level of atmospheric environment monitoring equipment and the quality of products have steadily improved,and a technical&production system that can meet the requirements of routine monitoring activities has been initiated.It is expected that domestic atmospheric environment monitoring technology and equipment will be able to meet future demands for routine monitoring activities in China and provide scientific assistance for addressing air pollution problems.展开更多
This study investigates the influence of major climatic modes on the interannual variability of the annual minimum extent of Antarctic sea ice.It shows that the Southern Annular Mode(SAM),the Indian Ocean Dipole(IOD),...This study investigates the influence of major climatic modes on the interannual variability of the annual minimum extent of Antarctic sea ice.It shows that the Southern Annular Mode(SAM),the Indian Ocean Dipole(IOD),and the El Niño-Southern Oscillation(ENSO),along with the total sea ice condition during the preceding spring,serve as precursor signals of February sea ice extent(SIE).These climate modes interact,energizing the Pacific-South American pattern(PSA),which deepens and shifts the Amundsen Sea Low(ASL)westward in spring.This pattern generates a dipole sea ice anomaly characterized by an increase in sea ice in the northern Ross Sea but a decrease in ice in the Bellingshausen and northern Weddell Seas.However,as the season transitions into summer,the ASL exerts a pronounced delayed effect,contributing to widespread sea ice loss across West Antarctica.Strong southerly winds on the western flank of the ASL push sea ice away from the inner Ross Sea,exposing coastal waters that absorb solar radiation,thereby accelerating ice melt through positive ice-albedo feedback.Simultaneously,northwesterly winds on the eastern flank transport warm air toward the Bellingshausen and northern Weddell Seas,intensifying ice loss in these regions.Furthermore,the active PSA is accompanied by a tripole sea surface temperature pattern characterized by warming in the Weddell Sea,which promotes continued ice melt.The co-occurrence of an exceptionally positive SAM,a La Niña,and a strong negative IOD during spring 2022,combined with lower-than-normal total spring SIE,ultimately contributed to the record-low Antarctic SIE observed in February 2023.展开更多
The Beijing 325 m meteorological tower stands as a pivotal research platform for exploring atmospheric boundary layer physics and atmospheric chemistry.With a legacy spanning 45 years,the tower has played a crucial ro...The Beijing 325 m meteorological tower stands as a pivotal research platform for exploring atmospheric boundary layer physics and atmospheric chemistry.With a legacy spanning 45 years,the tower has played a crucial role in unraveling the complexities of urban air pollution,atmospheric processes,and climate change in Beijing,China.This review paper provides a comprehensive overview of the measurements on the tower over the past two decades.Through long-term comprehensive observations,researchers have elucidated the intricate relationships between anthropogenic emissions,meteorological dynamics,and atmospheric composition,shedding light on the drivers of air pollution and its impacts on public health.The vertical measurements on the tower also enable detailed investigations into boundary layer dynamics,turbulent mixing,and pollutant dispersion,providing invaluable data for validating chemical transport models.Key findings from the tower’s research include the identification of positive feedback mechanisms between aerosols and the boundary layer,the characterization of pollutant sources and transport pathways,the determination of fluxes of gaseous and particulate species,and the assessment of the effectiveness of pollution control measures.Additionally,isotopic measurements have provided new insights into the sources and formation processes of particulate matter and reactive nitrogen species.Finally,the paper outlines future directions for tower-based research,emphasizing the need for long-term comprehensive measurements,the development of innovative tower platforms,and integration of emerging technologies.展开更多
PM_(2.5) and black carbon(BC)are important air pollutants impacting radiation balance,air quality,health,and ecosystems.Ozone(O_(3))levels are increasing despite decreases in other pollutants,posing a challenge for po...PM_(2.5) and black carbon(BC)are important air pollutants impacting radiation balance,air quality,health,and ecosystems.Ozone(O_(3))levels are increasing despite decreases in other pollutants,posing a challenge for pollution control,especially in coastal cities like Zhoushan,where the monsoonal climate can exacerbate PM_(2.5) and ozone pollution.This study conducted continuous online measurements of major atmospheric pollutants in Zhoushan,Zhejiang Province,in 2020.The results indicate that the highest contribution from local air masses in Zhoushan is observed in spring,accounting for 17.7%,while the greatest average contribution from northern Zhejiang Province,Jiangsu Province,and Shanghai occurs in winter,at 18.5%.Pollutant concentrationswere seasonally variable,with PM_(2.5),BC,and sulfur dioxide concentrations 56.6%,36%,and 58.2%higher in the cold season compared to the warm season.The O_(3) in spring is approximately 50%higher than that in summer.Ship emissions significantly contributed to BC,nitrogen oxides(NO_(x)),and carbon monoxide in Zhoushan.In spring,PM_(2.5) sources included photochemical processes and northern air mass transport,while in winter,PM_(2.5) was due to regional transport.The inhibitory effect of PM_(2.5) on O_(3) formation in the Zhoushan area is relatively weak.Reducing NO_(x) emissions may increase O_(3),emphasizing the need for volatile organic compounds monitoring and regional control measures to improve air quality and ensure sustainable development in Zhoushan.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
An analysis of time variations of the earth’s length of day (LOD) versus atmospheric geopotential height fields and lunar phase is presented. A strong correlation is found between LOD and geopotential height from whi...An analysis of time variations of the earth’s length of day (LOD) versus atmospheric geopotential height fields and lunar phase is presented. A strong correlation is found between LOD and geopotential height from which a close relationship is inferred and found between atmospheric circulation and the lunar cycle around the earth. It is found that there is a 27.3-day and 13.6-day east-west oscillation in the atmospheric circulation following the lunar phase change. The lunar revolution around the earth strongly influences the atmospheric circulation. During each lunar cycle around the earth there is, on average, an alternating change of 6.8-day-decrease, 6.8-day-increase, 6.8-day-decrease and 6.8-day-increase in atmospheric zonal wind, atmospheric angular momentum and LOD. The dominant factor producing such an oscillation in atmospheric circulation is the periodic change of lunar declination during the lunar revolution around the earth. The 27.3- day and 13.6-day atmospheric oscillatory phenomenon is akin展开更多
基金supported by the National Natural Science Foundation of China(Grant No.42261134532,42405059,and U2342212)。
文摘This study investigates the relationship between atmospheric stratification (i.e., static stability given by N^(2)) and the vertical energy transfer of stationary planetary waves, and further illustrates the underlying physical mechanism. Specifically, for the simplified case of constant stratospheric N^(2), the refractive index square of planetary waves has a theoretical tendency to increase first and then decrease with an increased N^(2), whereas the group velocity weakens. Mechanistically, this behavior can be understood as an intensified suppression of vertical isentropic surface displacement caused by meridional heat transport of planetary waves under strong N^(2) conditions. Observational analysis corroborates this finding, demonstrating a reduction in the vertical-propagation velocity of waves with increased N^(2). A linear, quasi- geostrophic, mid-latitude beta-plane model with a constant background westerly wind and a prescribed N^(2) applicable to the stratosphere is used to obtain analytic solutions. In this model, the planetary waves are initiated by steady energy influx from the lower boundary. The analysis indicates that under strong N^(2) conditions, the amplitude of planetary waves can be sufficiently increased by the effective energy convergence due to the slowing vertical energy transfer, resulting in a streamfunction response in this model that contains more energy. For N^(2) with a quasi-linear vertical variation, the results bear a resemblance to the constant case, except that the wave amplitude and oscillating frequency show some vertical variations.
基金supported by the National Natural Science Foundation of China(Grant Nos.U2342210 and 42275043)the National Institute of Natural Hazards,Ministry of Emergency Management of China(Grant Nos.J2223806,ZDJ2024-25 and ZDJ2025-34)。
文摘Climate models are essential for understanding past,present,and future changes in atmospheric circulation,with circulation modes providing key sources of seasonal predictability and prediction uncertainties for both global and regional climates.This study assesses the performance of models participating in phase 6 of the Coupled Model Intercomparison Project in simulating interannual variability modes of Northern Hemisphere 500-hPa geopotential height during winter and summer,distinguishing predictable(potentially predictable on seasonal or longer timescales)and unpredictable(intraseasonal and essentially unpredictable at long range)components,using reanalysis data and a variance decomposition method.Although most models effectively capture unpredictable modes in reanalysis,their ability to reproduce dominant predictable modes-specifically the Pacific-North American pattern,Arctic Oscillation,and Western Pacific Oscillation in winter,and the East Atlantic and North Atlantic Oscillations in summer-varies notably.An optimal ensemble is identified to distinguish(a)predictable-external modes,dominated by external forcing,and(b)predictable-internal modes,associated with slow internal variability,during the historical period(1950-2014)and the SSP5-8.5 scenario(2036-2100).Under increased radiative forcing,the leading winter/summer predictable-external mode exhibits a more uniform spatial distribution,remarkably larger trend and annual variance,and enhanced height-sea surface temperature(SST)covariance under SSP5-8.5 compared to historical conditions.The dominant winter/summer predictable-internal modes also exhibit increased variance and height-SST covariance under SSP5-8.5,along with localized changes in spatial configuration.Minimal changes are observed in spatial distribution or variance for dominant winter/summer unpredictable modes under SSP5-8.5.This study,from a predictive perspective,deepens our understanding of model uncertainties and projected changes in circulations.
文摘The year 2024 marked the 40th anniversary of Advances in Atmospheric Sciences(AAS),as well as the centenary of the Chinese Meteorological Society(CMS).The inaugural issue of AAS was published in 1984,initially being sponsored primarily by Chinese National Committee for the International Association of Meteorological and Atmospheric Sciences(IAMAS)and the Institute of Atmospheric Physics at the Chinese Academy of Sciences.In 2006,Springer became AAS’s international publisher.Then,in 2015,the CMS joined in sponsoring AAS,and in the same year,AAS also became an affiliated journal of the IAMAS.These milestone events helped broaden the reach of AAS,culminating in the journal establishing itself as a truly international journal supporting the advancement of the atmospheric sciences.
基金jointly funded by the National Science Foundation of China(No.42405069)the University Natural Sciences Research Project of Anhui Province(Nos.2023AH052201 and 2023AH052184)+1 种基金the 2023 Talent Research Fund Project of Hefei University(No.23RC01)the Technical Development Project of Hefei University(Nos.902/22050124128,902/22050124148 and 902/22050124250)。
文摘Atmospheric turbulence is an important parameter affecting laser atmospheric transmission.This paper reports on a self-developed atmospheric turbulence detection Li DAR system(scanning differential image motion Li DAR(DIM-Li DAR)system).By designing and simulating the optical system of atmospheric turbulence detection Li DAR,the basic optical imaging accuracy has been determined.
基金supported by the National Natural Science Foundation of China(Grant Nos.42150204 and 2288101)supported by the China National Postdoctoral Program for Innovative Talents(BX20230045)the China Postdoctoral Science Foundation(2023M730279)。
文摘A nonlinear multi-scale interaction(NMI)model was proposed and developed by the first author for nearly 30 years to represent the evolution of atmospheric blocking.In this review paper,we first review the creation and development of the NMI model and then emphasize that the NMI model represents a new tool for identifying the basic physics of how climate change influences mid-to-high latitude weather extremes.The building of the NMI model took place over three main periods.In the 1990s,a nonlinear Schr?dinger(NLS)equation model was presented to describe atmospheric blocking as a wave packet;however,it could not depict the lifetime(10-20 days)of atmospheric blocking.In the 2000s,we proposed an NMI model of atmospheric blocking in a uniform basic flow by making a scale-separation assumption and deriving an eddyforced NLS equation.This model succeeded in describing the life cycle of atmospheric blocking.In the 2020s,the NMI model was extended to include the impact of a changing climate mainly by altering the basic zonal winds and the magnitude of the meridional background potential vorticity gradient(PVy).Model results show that when PVy is smaller,blocking has a weaker dispersion and a stronger nonlinearity,so blocking can be more persistent and have a larger zonal scale and weaker eastward movement,thus favoring stronger weather extremes.However,when PVy is much smaller and below a critical threshold under much stronger winter Arctic warming of global warming,atmospheric blocking becomes locally less persistent and shows a much stronger westward movement,which acts to inhibit local cold extremes.Such a case does not happen in summer under global warming because PVy fails to fall below the critical threshold.Thus,our theory indicates that global warming can render summer-blocking anticyclones and mid-to-high latitude heatwaves more persistent,intense,and widespread.
文摘Restoration of phase aberrations is crucial for addressing atmospheric turbulence in light propagation.Traditional restoration algorithms based on Zernike polynomials(ZPs)often encounter challenges related to high computational complexity and insufficient capture of high-frequency phase aberration components,so we proposed a Principal-Component-Analysis-based method for representing phase aberrations.This paper discusses the factors influencing the accuracy of restoration,mainly including the sample space size and the sampling interval of D/r_(0),on the basis of characterizing phase aberrations by Principal Components(PCs).The experimental results show that a larger D/r_(0)sampling interval can ensure the generalization ability and robustness of the principal components in the case of a limited amount of original data,which can help to achieve high-precision deployment of the model in practical applications quickly.In the environment with relatively strong turbulence in the test set of D/r_(0)=24,the use of 34 terms of PCs can improve the corrected Strehl ratio(SR)from 0.007 to 0.1585,while the Strehl ratio of the light spot after restoration using 34 terms of ZPs is only 0.0215,demonstrating almost no correction effect.The results indicate that PCs can serve as a better alternative in representing and restoring the characteristics of atmospheric turbulence induced phase aberrations.These findings pave the way to use PCs of phase aberrations with fewer terms than traditional ZPs to achieve data dimensionality reduction,and offer a reference to accelerate and stabilize the model and deep learning based adaptive optics correction.
基金supported in part by the Meteorological Joint Funds of the National Natural Science Foundation of China(Grant No.U2142211)by the National Key Research and Development Program of China(Grant No.2020YFA0608002)+4 种基金by the National Natural Science Foundation of China(Grant Nos.42075141 and 42341202)by the China National Postdoctoral Program for Innovative Talents(Grant No.BX20230071)by the National Natural Science Foundation of China for Youth(Grant No.42205191)by the Shanghai Municipal Science and Technology Major Project(Grant No.2021SHZDZX0100)the Fundamental Research Funds for the Central Universities。
文摘Subseasonal-to-seasonal(S2S)forecasting for East Asian atmospheric circulation poses significant challenges for conventional numerical weather prediction(NWP)models.Recently,deep learning(DL)models have demonstrated significant potential in further enhancing S2S forecasts beyond the capabilities of NWP models.However,most current DLbased S2S forecasting models largely overlook the role of global predictors from multiple spheres,such as ocean,land,and atmosphere domains,that are crucial for effective S2S forecasting.In this study,we introduce EAAC-S2S,a tailored DL model for S2S forecasting of East Asian atmospheric circulation.EAAC-S2S employs the cross-attention mechanism to couple atmospheric circulations over East Asia with representative multi-sphere(i.e.,atmosphere,land,and ocean)variables,providing pentad-averaged circulation forecasts up to 12 pentads ahead throughout all seasons.Experimental results demonstrate,on the S2S time scale,that EAAC-S2S consistently outperforms the European Centre for MediumRange Weather Forecasts(ECMWF)Ensemble Prediction System by decreasing the root-mean-square error(RMSE)by3.8%and increasing the anomaly correlation coefficient(ACC)by 8.6%,averaged across all 17 predictands.Our system also shows good skill for examples of heatwaves and the South China Sea Subtropical High Intensity Index(SCSSHII).Moreover,quantitative interpretability analysis including multi-sphere attribution and attention visualization are conducted for the first time in a DL S2S model,where the traced predictability aligns well with prior meteorological knowledge.We hope that our results have the potential to advance research in data-driven S2S forecasting.
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(Nos.42475125,42105117,42021004 and 41975143)the National Key R&D Program of China(Nos.2019YFA0607202 and 2020YFA0607501)+4 种基金Jiangsu Science Foundation for Distinguished Young Scholar(No.BK20220055)the 333 Project of Jiangsu Province(No.BRA2017402)the R&D Foundation of Jiangsu Province,China(No.BK20220020)Zhejiang Provincial Basic Public Welfare Research Project(No.LGF22D050004)the Key Laboratory of Ecosystem Carbon Source and Sink,China Meteorological Administration(ECSSCMA).
文摘China is the largest emitter of anthropogenic CO_(2) globally,with its cities recognized as significant emission hotspots.Consequently,evaluating anthropogenic CO_(2) emissions and the carbon neutral capability(CNC)of Chinese cities is critical for climate change mitigation.Despite this importance,no studies to date have assessed recent and future city-scale CNCs using the top-down atmospheric inversion approach,revealing substantial knowledge gaps regarding regional CO_(2) budgets.To address these issues,this research focused on Hangzhou,a megacity known for having the highest forest cover among China’s provincial capitals,as study region.Year-round atmospheric CO_(2) concentration measurements were conducted from December 2020 to November 2021 at two sites:one urban and one suburban.These observations,along with their difference,were utilized to derive city-scale posterior anthropogenic CO_(2) emissions and to evaluate recent and future CNCs.Our key findings are as follows:(1)The manufacturing industry,energy industry and oil refineries/transformation industry were identified as the largest contributors to urban-suburban CO_(2) difference,accounting for 36.5%,21.3%,and 16.6%,respectively.Additionally,82.5%,65.2%,81.2%and 86.3%of total anthropogenic CO_(2) enhancements were attributed to emissions within Hangzhou city in winter,spring,summer and autumn,respectively.(2)The posterior annual anthropogenic CO_(2) emission for Hangzhouwas estimated at 4.65(±0.72)×10^(10) kg/a,indicating significant biases among different prior CO_(2) emission inventories.The annual biological CO_(2) sink,derived from multiple products,was estimated at-0.48(±0.16)×10^(10) kg.(3)The calculated CNC for 2021was 10.3%±3.4%,highlighting a substantial gap towards achieving full carbon neutrality.Considering potential increases in ecosystem carbon sinks due to forest age and uncertainties from climate change,it was predicted that at least 65.2%-82.6%of anthropogenic CO_(2) emissions must be reduced to achieve the goal of full carbon neutrality by year of 2060.
基金financial support from the National Natural Science Foundation of China(Grant Nos.42274112 and 41804016)supported by Danmarks Frie Forskningsfond[https://doi.org/10.46540/2035-00247B]through the DANSk-LSM project and HPC Platform of Huazhong University of Science and Technology。
文摘Atmospheric de-aliasing is one of the most important background models for recovering Earth's temporal gravity field from gravity satellite missions.To meet the needs of China's gravimetric satellite platform,an independent atmospheric dealiasing model that relies on Chinese meteorological data needs to be developed.The release of CRA-40,as the firstgeneration Chinese atmospheric reanalysis,provides the opportunity.This study proposes a revised modeling method to calibrate CRA-40 and develops a new atmospheric de-aliasing model(HUST-CRA,2002-20).Intensive assessments are made between HUST-CRA and the latest official de-aliasing product of the international gravity satellite mission.The tidal components of the two products demonstrate high consistency,e.g.,the spatial correlation for the major tide S_1 is 0.96.The non-tidal components of the two products are also equivalent:(1)the temporal correlation of low-degree terms is higher than 0.97,except for the term of S22(0.93);(2)the spectral correlation of degree geoid height up to degree/order 100 is as high as 0.99;(3)the confidence interval of the spatial correlation(2002-20)is[0.971,0.995]at a confidence level of 95%;and(4)the difference in KBRR(K-band range rate)residuals is less than 0.08μm s^(-1),the difference in the derived temporal gravity field is less than 0.32 mm in terms of geoid height,and both are apparently beyond the ability of the current gravity satellite mission.This confirms that CRA-40 is of high quality and that the derived de-aliasing product,HUST-CRA,is accurate enough to be used in both Chinese and international gravity satellite missions.
基金supported by the National Key Research and Development Program of China(No.2021YFC2300904)the National Natural Science Foundation of China(No.42101128).
文摘Ice cores play an important role in the reconstruction of historical atmospheric information.The glacier of the Tibetan Plateau is influenced by the Indian monsoon and westerly winds,which divide the Tibetan Plateau into monsoon-and westly influenced regions.These atmospheric circulations bring distinct microbial communities to glaciers,with the microbial dispersal process being also influenced by atmospheric factors.However,the potential influence of between bacterial abundance and atmospheric factors is not well known.To reveal potential mechanisms controlling bacterial abundance between two regions,we obtained bacterial abundance and atmospheric records for the past 46 years from two ice cores located within these regions.Statistical regression models were constructed to fit the relationship between bacterial abundance and atmospheric factors.Generalized additive model(GAM)was superior in modeling bacterial abundance compared with linear models and showed that the key factors affecting bacterial abundance were different in the monsoon-and westerly-dominated regions.Specifically,atmospheric dust and black carbon were the key factors for the monsoon-dominated region,and westerly index was the key factor for the westerly-dominated region.The model outputs confirm that atmospheric black carbon plays an important role in affecting bacterial abundance for the glacier located within the monsoon-dominated region,particularly in recent decades.The model also predicted that bacterial abundance will increase by 27%with a doubled black carbon deposition.We quantify and model for the first time that relationship between bacterial abundance and atmospheric black carbon in Tibetan glaciers change over time based on GAM models.
基金supported by the National Natural Science Foundation of China(No.42105159)the Key Technologies Research and Development Program(No.2022YFF0606400)+2 种基金China Meteorological Administration“Research on value realization of climate ecological products”Youth Innovation Team Project(No.CMA2024QN15)Jiangxi Meteorological Technology Project(Nos.JX2021Z06,JX2022Z03,and JX2023Z03)the Joint Open Fund of the Institute of Atmospheric Environment,China Meteorological Administration,Shenyang and Key Laboratory of Agro-Meteorological Disasters of Liaoning Province(No.2024SYIAEKFZD05)。
文摘Although atmospheric CO_(2) observations are becoming increasingly widespread in China,the identification of CO_(2) emission sources is still scarce,especially in undeveloped Central China.To effectively address this issue,in a typical site in Central China,the simultaneous measurements of atmospheric CO_(2),CO,andδ^(13)C were conducted,and the characteristics of CO_(2) emission sources were systematically investigated based on the relationships among CO_(2),CO,andδ^(13)C.The average CO_(2)/CO ratio of winter increased from 52.4 ppm/ppm during 2018–2020 to 65.1 ppm/ppm during 2021–2022,which confirmed the improvement of energy consumption efficiency in China.Air-mass transportation from central China and Yangtze River Delta regions contributed largely to higher CO_(2)/CO ratios in 2021–2022.A highermean CO_(2)/CO ratio appeared during the morning rush hours(60.3 ppm/ppm)than in the afternoon rush hours(51.4 ppm/ppm)in winter.In addition,the meanδ^(13)C value of CO_(2) sources(δ^(13)Cs)also displayed more negative values during the morning rush hours(-28.3‰)than the afternoon rush hours(-22.2‰),suggesting the significant influence of vehicle and natural gas usage at themorning rush hours and the impact of straw burning in the afternoon rush hours.The meanδ^(13)Cs was-24.7‰for winter and-21.9‰for vegetation season,implying the main contribution of coal in winter and the impact of C4 plants during the vegetation season.The contribution of biogenic respiration CO_(2) was inferred to exceed 50%during the nighttime of summer according to the obtained meanδ^(13)C value of biogenic respiration CO_(2),which was calculated to be-21.4‰.
基金Science and Technology Planning Project of Guangdong Province (2023B1212060019)Natural Science Foundation of China (42175086)Innovation Group Project of Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai)(SML2023SP208)。
文摘Although the Chinese new-generation Fengyun-4B(FY-4B) geostationary satellite Atmospheric Motion Vector(AMV) products became operational in June 2022, their accuracy and utility remain largely unexamined. This study comprehensively evaluates FY-4B AMV products for August and October 2023, as well as January and April 2024,exploring their application in monitoring the South China Sea Summer Monsoon(SCSSM) onset. The results indicate that AMV products derived from the upper-level water vapor absorption channel(AMV_WV) and the infrared channel(AMV_IR) demonstrate high accuracy when compared with ERA5 reanalysis data. The root mean square error(RMSE) is mostly between 4.5 m s^(–1)and 6.4 m s^(–1), with coefficients of determination(R2) values ranging from 0.7 to 0.8, indicating the overall reliability of FY-4B AMVs. The observation errors of AMVs exhibit significant vertical structure characteristics. Specifically, the AMV_WV products demonstrate superior accuracy above 350 h Pa, while the AMV_IR products exhibit reduced errors in the layers between 200–500 h Pa and 700–950 h Pa. Spatially, most areas exhibit low observation errors for AMVs, while clear-sky weather and deep convective cloud systems can increase errors. A lack of clouds or water vapor may reduce the number of observation samples in some areas, leading to unstable RMSE performance, which is particularly evident for AMV_WV RMSE around 25°–30°N in January and near 25°S in August. Deep convective cloud systems can influence AMV retrieval results, leading to systematic observation errors, especially for the infrared channel.Additionally, AMV_WV is more reliable during the daytime, with a lower RMSE compared to nighttime, while AMV_IR exhibits a diverging diurnal variation pattern. Finally, the FY-4B AMV_WV products were applied to monitor the SCSSM event in 2024. Significant zonal wind direction reversal characteristics were observed in key regions around the onset date,indicating that AMVs can serve as effective indicators for monitoring the SCSSM onset.
基金supported by the National Natural Science Foundation of China(Nos.21976106,42005092,and 42105111)the Natural Science Foundation of Shandong Province(Nos.ZR2020QD058 and ZR2021QD144)+1 种基金the Introduction and Cultivation Plan for Young Innovative Talents of Colleges and Universities by the Education Department of Shandong Province(No.142,2019)。
文摘Marine biological activity has long been recognized to impact the atmospheric chemistry of coastal areas.In this work,we monitored the seasonal variation of carbonyl compounds in the coastal city of Qingdao,located in the north of China’s coastline and the south of Jiaodong Peninsula,with the vast hinterland in the west.The mean total concentration of the 15 carbonyls varied significantly between seasons,with the highest observed in autumn(10.2±6.2 ppbv),followed by spring(9.0±3.0 ppbv),winter(6.4±4.0 ppbv)and summer(3.4±1.4 ppbv).Using bivariate analysis,the agricultural emissions from inland areas were responsible for the high levels of carbonyls in the autumn.In summer,clean and humid sea winds helped reduce the concentration of carbonyls,but they also brought air masses from vegetation,and marine organisms,which contributed to high levels of carbonyls in the spring of coastal areas.The observation-based chemistry box model found that the forma-tion of formaldehyde and acetaldehyde was primarily controlled by the RO+O2 reaction,and alkenes oxidation was the main contributing factor.Based on the OH radical loss rate(LOH)and ozone formation potential(OFP)calculation,we found that autumn and spring seasons have significantly higher values of LOH and OFP than winter and summer due to the presence of high concentrations of carbonyl compounds.Therefore,it is believed that these carbonyl compounds primarily originate from agricultural activities,and marine air influences the atmospheric chemistry of the coastal areas.
基金supported by the National Key Research and Development Program of China(No.2019YFC0214802)the Youth Innovation Promotion Association,CAS(No.2019434)the Sino-German Mobility programme(No.M-0036)。
文摘Accurate monitoring of the atmospheric environment and its evolution are important for understanding the sources,chemical mechanisms,and transport processes of air pollution and carbon emissions in China,and for regulatory and control purposes.This study gives an overview of atmospheric environment monitoring technology and equipment in China and summarizes the major achievements obtained in recent years.China has made great progress in the development of atmospheric environment monitoring technology and equipment with decades of effort.The manufacturing level of atmospheric environment monitoring equipment and the quality of products have steadily improved,and a technical&production system that can meet the requirements of routine monitoring activities has been initiated.It is expected that domestic atmospheric environment monitoring technology and equipment will be able to meet future demands for routine monitoring activities in China and provide scientific assistance for addressing air pollution problems.
基金supported by the National Natural Science Foundation of China (Grant Nos.42288101 and 42375045)
文摘This study investigates the influence of major climatic modes on the interannual variability of the annual minimum extent of Antarctic sea ice.It shows that the Southern Annular Mode(SAM),the Indian Ocean Dipole(IOD),and the El Niño-Southern Oscillation(ENSO),along with the total sea ice condition during the preceding spring,serve as precursor signals of February sea ice extent(SIE).These climate modes interact,energizing the Pacific-South American pattern(PSA),which deepens and shifts the Amundsen Sea Low(ASL)westward in spring.This pattern generates a dipole sea ice anomaly characterized by an increase in sea ice in the northern Ross Sea but a decrease in ice in the Bellingshausen and northern Weddell Seas.However,as the season transitions into summer,the ASL exerts a pronounced delayed effect,contributing to widespread sea ice loss across West Antarctica.Strong southerly winds on the western flank of the ASL push sea ice away from the inner Ross Sea,exposing coastal waters that absorb solar radiation,thereby accelerating ice melt through positive ice-albedo feedback.Simultaneously,northwesterly winds on the eastern flank transport warm air toward the Bellingshausen and northern Weddell Seas,intensifying ice loss in these regions.Furthermore,the active PSA is accompanied by a tripole sea surface temperature pattern characterized by warming in the Weddell Sea,which promotes continued ice melt.The co-occurrence of an exceptionally positive SAM,a La Niña,and a strong negative IOD during spring 2022,combined with lower-than-normal total spring SIE,ultimately contributed to the record-low Antarctic SIE observed in February 2023.
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDB0760200)the National Natural Science Foundation of China(Grant Nos.42330605 and 42377101).
文摘The Beijing 325 m meteorological tower stands as a pivotal research platform for exploring atmospheric boundary layer physics and atmospheric chemistry.With a legacy spanning 45 years,the tower has played a crucial role in unraveling the complexities of urban air pollution,atmospheric processes,and climate change in Beijing,China.This review paper provides a comprehensive overview of the measurements on the tower over the past two decades.Through long-term comprehensive observations,researchers have elucidated the intricate relationships between anthropogenic emissions,meteorological dynamics,and atmospheric composition,shedding light on the drivers of air pollution and its impacts on public health.The vertical measurements on the tower also enable detailed investigations into boundary layer dynamics,turbulent mixing,and pollutant dispersion,providing invaluable data for validating chemical transport models.Key findings from the tower’s research include the identification of positive feedback mechanisms between aerosols and the boundary layer,the characterization of pollutant sources and transport pathways,the determination of fluxes of gaseous and particulate species,and the assessment of the effectiveness of pollution control measures.Additionally,isotopic measurements have provided new insights into the sources and formation processes of particulate matter and reactive nitrogen species.Finally,the paper outlines future directions for tower-based research,emphasizing the need for long-term comprehensive measurements,the development of innovative tower platforms,and integration of emerging technologies.
基金supported by Zhejiang Province Science Fund for Distinguished Young Scholars(No.LR24D050001)the Joint Funds of Zhejiang Provincial Natural Science Foundation of China(No.LZJMZ23D050002)+3 种基金the National Natural Science Foundation of China(No.42175116)the Scientific Research Foundation for Guilin University of Technology(No.GUTQDJJ2023046)supported by Guangxi Engineering Research Center of Comprehensive Treatment for Agricultural Non-Point Source Pollutionthe Modern Industry College of Ecology and Environmental Protection,Guilin University of Technology.
文摘PM_(2.5) and black carbon(BC)are important air pollutants impacting radiation balance,air quality,health,and ecosystems.Ozone(O_(3))levels are increasing despite decreases in other pollutants,posing a challenge for pollution control,especially in coastal cities like Zhoushan,where the monsoonal climate can exacerbate PM_(2.5) and ozone pollution.This study conducted continuous online measurements of major atmospheric pollutants in Zhoushan,Zhejiang Province,in 2020.The results indicate that the highest contribution from local air masses in Zhoushan is observed in spring,accounting for 17.7%,while the greatest average contribution from northern Zhejiang Province,Jiangsu Province,and Shanghai occurs in winter,at 18.5%.Pollutant concentrationswere seasonally variable,with PM_(2.5),BC,and sulfur dioxide concentrations 56.6%,36%,and 58.2%higher in the cold season compared to the warm season.The O_(3) in spring is approximately 50%higher than that in summer.Ship emissions significantly contributed to BC,nitrogen oxides(NO_(x)),and carbon monoxide in Zhoushan.In spring,PM_(2.5) sources included photochemical processes and northern air mass transport,while in winter,PM_(2.5) was due to regional transport.The inhibitory effect of PM_(2.5) on O_(3) formation in the Zhoushan area is relatively weak.Reducing NO_(x) emissions may increase O_(3),emphasizing the need for volatile organic compounds monitoring and regional control measures to improve air quality and ensure sustainable development in Zhoushan.
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.
文摘An analysis of time variations of the earth’s length of day (LOD) versus atmospheric geopotential height fields and lunar phase is presented. A strong correlation is found between LOD and geopotential height from which a close relationship is inferred and found between atmospheric circulation and the lunar cycle around the earth. It is found that there is a 27.3-day and 13.6-day east-west oscillation in the atmospheric circulation following the lunar phase change. The lunar revolution around the earth strongly influences the atmospheric circulation. During each lunar cycle around the earth there is, on average, an alternating change of 6.8-day-decrease, 6.8-day-increase, 6.8-day-decrease and 6.8-day-increase in atmospheric zonal wind, atmospheric angular momentum and LOD. The dominant factor producing such an oscillation in atmospheric circulation is the periodic change of lunar declination during the lunar revolution around the earth. The 27.3- day and 13.6-day atmospheric oscillatory phenomenon is akin
