During high-temperature periods in summer,formaldehyde(HCHO)levels increase due to secondary production.However,recent studies have also shown a rise in the HCHO concentration in winter,but the underlying cause remain...During high-temperature periods in summer,formaldehyde(HCHO)levels increase due to secondary production.However,recent studies have also shown a rise in the HCHO concentration in winter,but the underlying cause remains unclear.Here,HCHO observations in urban Beijing were conducted,the impact of meteorological differences between warm and cold seasons to HCHO concentrations was investigated.Additionally,the positive matrix factorization model was applied to the source apportionment of HCHO,with a focus on changes during pollution events.The results indicated that,during warm seasons,the secondary production of HCHO was driven by high temperature influenced by the low-pressure front,with the contribution of secondary production+background peaking at 85.9% in the afternoon,exhibiting a unimodal diurnal variation.Conversely,during cold seasons,the influence of a uniform pressure field,coupled with weak winds,low boundary layers and high humidity,led to HCHO accumulation from primary emissions,resulting in multiday highconcentration pollution.During the most severe pollution periods,anthropogenic primary emissions contributed up to 91.7%.Therefore,while the contribution of volatile organic compounds to HCHO levels through secondary production has been recognized,the significant impact of primary emissions during cold seasons cannot be overlooked.展开更多
This study quantified the regional damages resulting from temperature and sea level changes using the Regional Integrated of Climate and Economy(RICE)model,as well as the effects of enabling and disabling the climate ...This study quantified the regional damages resulting from temperature and sea level changes using the Regional Integrated of Climate and Economy(RICE)model,as well as the effects of enabling and disabling the climate impact module on future emission pathways.Results highlight varied damages depending on regional economic development and locations.Specifically,China and Africa could suffer the most serious comprehensive damages caused by temperature change and sea level rise,followed by India,other developing Asian countries(OthAsia),and other high-income countries(OHI).The comprehensive damage fractions for China and Africa are projected to be 15.1%and 12.5%of gross domestic product(GDP)in 2195,with corresponding cumulative damages of 124.0 trillion and 87.3 trillion United States dollars(USD)from 2005 to 2195,respectively.Meanwhile,the comprehensive damage fractions in Japan,Eurasia,and Russia are smaller and projected to be lower than 5.6%of GDP in 2195,with cumulative damages of 6.8 trillion,4.2 trillion,and 3.3 trillion USD,respectively.Additionally,coastal regions like Africa,the European Union(EU),and OHI show comparable damages for sea level rise and temperature change.In China,however,sea level-induced damages are projected to exceed those from temperature changes.Moreover,this study indicates that switching the damage modules on or off affects the regional and global emission trajectories,but the magnitude is relatively small.By 2195,global emissions under the experiments with all of the damage modules switched off,only the sea level damage module switched on,and only the temperature damage module switched on,were 3.5%,2.3%and 1.2%higher than those with all of the damage modules switched on,respectively.展开更多
The observations from satellite microwave sounding instruments have been proven to significantly impact severe weather monitoring and numerical weather prediction.Recent research indicates that the maturation of digit...The observations from satellite microwave sounding instruments have been proven to significantly impact severe weather monitoring and numerical weather prediction.Recent research indicates that the maturation of digitally channelized technology enables hyperspectral microwave sounding.However,the specific effects of these hyperspectral channels on the retrieval of temperature and humidity profiles remain uncertain.In this study,a novel microwave to terahertz sounder(MTS)is explored.Specifically,the impacts of 50–60 GHz(V band)hyperspectral channels and380–420 GHz(Y1 and Y2 band)terahertz channels on one-dimensional variational retrieval(1DVAR)results are investigated through various channel configurations.Initially,the information entropy of the channels is evaluated.When compared to the currently orbiting microwave sounders,the use of V-band hyperspectral channels can reduce the root-mean-square error(RMSE)of the retrieved temperature near the tropopause by approximately 14%.The inclusion of Y1 and Y2 band channels also positively contributes to the retrieved profiles.Compared to the currently deployed microwave sounders,this leads to a 2%reduction in temperature RMSE and a 5%reduction in humidity RMSE.The optimal channel configuration based on information entropy results in a temperature RMSE reduction of around 5.6%and a humidity RMSE reduction of 4.1%.Furthermore,the influence of observation noises on the retrieval results is examined.It is discovered that halving the noise can decrease the temperature RMSE by 13%and the humidity RMSE by 6%.Overall,the new sounding channels offer greater potential for enhancing temperature and humidity sounding,and they may potentially improve atmospheric measurements and the utilization of microwave observations in numerical weather prediction.展开更多
Tropical cyclones(TCs),including tropical depressions and different categories of typhoons,hurricanes,and cyclonic storms,mostly originate over the oceans in the absence of direct observations.Thus,detailed monitoring...Tropical cyclones(TCs),including tropical depressions and different categories of typhoons,hurricanes,and cyclonic storms,mostly originate over the oceans in the absence of direct observations.Thus,detailed monitoring and analysis of TCs has always been an unsolved problem.In the recent 20 years,great changes have taken place in domestic and foreign TC monitoring techniques,imposing a significant impact on TC operations and research.Some new technologies and products gradually emerge to support operations,with improved monitoring accuracy.In this paper,the progress on TC monitoring and analysis via meteorological satellites,radars,and airplanes in China and the world is reviewed,compared,and summarized,with special focuses on multisatellite fusion observations,in situ aircraft measurements,and some unconventional observation equipment such as rockets,saildrones,and underwater gliders.On this basis,the paper points out future directions for improving TC monitoring and analysis in aid of better TC forecast and early warning.展开更多
基金supported by the National Natural Science Foundation of China(Nos.42075097 and 42177081)the National Key R&D Program of China(No.2023YFC3706103)+2 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDB0760200)Beijing Municipal Natural Science Foundation(No.8222075)the Youth Cross Team Scientific Research Project of the Chinese Academy of Sciences(No.JCTD-2021-10)。
文摘During high-temperature periods in summer,formaldehyde(HCHO)levels increase due to secondary production.However,recent studies have also shown a rise in the HCHO concentration in winter,but the underlying cause remains unclear.Here,HCHO observations in urban Beijing were conducted,the impact of meteorological differences between warm and cold seasons to HCHO concentrations was investigated.Additionally,the positive matrix factorization model was applied to the source apportionment of HCHO,with a focus on changes during pollution events.The results indicated that,during warm seasons,the secondary production of HCHO was driven by high temperature influenced by the low-pressure front,with the contribution of secondary production+background peaking at 85.9% in the afternoon,exhibiting a unimodal diurnal variation.Conversely,during cold seasons,the influence of a uniform pressure field,coupled with weak winds,low boundary layers and high humidity,led to HCHO accumulation from primary emissions,resulting in multiday highconcentration pollution.During the most severe pollution periods,anthropogenic primary emissions contributed up to 91.7%.Therefore,while the contribution of volatile organic compounds to HCHO levels through secondary production has been recognized,the significant impact of primary emissions during cold seasons cannot be overlooked.
基金funded by the National Natu-ral Science Foundation of China(Grant No.42075044 and No.41975112)a project supported by the Innovation Group Project of the Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai)(Grant No.311022006).
文摘This study quantified the regional damages resulting from temperature and sea level changes using the Regional Integrated of Climate and Economy(RICE)model,as well as the effects of enabling and disabling the climate impact module on future emission pathways.Results highlight varied damages depending on regional economic development and locations.Specifically,China and Africa could suffer the most serious comprehensive damages caused by temperature change and sea level rise,followed by India,other developing Asian countries(OthAsia),and other high-income countries(OHI).The comprehensive damage fractions for China and Africa are projected to be 15.1%and 12.5%of gross domestic product(GDP)in 2195,with corresponding cumulative damages of 124.0 trillion and 87.3 trillion United States dollars(USD)from 2005 to 2195,respectively.Meanwhile,the comprehensive damage fractions in Japan,Eurasia,and Russia are smaller and projected to be lower than 5.6%of GDP in 2195,with cumulative damages of 6.8 trillion,4.2 trillion,and 3.3 trillion USD,respectively.Additionally,coastal regions like Africa,the European Union(EU),and OHI show comparable damages for sea level rise and temperature change.In China,however,sea level-induced damages are projected to exceed those from temperature changes.Moreover,this study indicates that switching the damage modules on or off affects the regional and global emission trajectories,but the magnitude is relatively small.By 2195,global emissions under the experiments with all of the damage modules switched off,only the sea level damage module switched on,and only the temperature damage module switched on,were 3.5%,2.3%and 1.2%higher than those with all of the damage modules switched on,respectively.
基金Supported by the National Key Research and Development Program of China(2021YFB3900400)National Natural Science Foundation of China(U2142212 and 42475165)+1 种基金Hunan Provincial Natural Science Foundation of China(2021JC0009)National Satellite Meteorological Centre of China Meteorological Administration(FY-APP-2022.0106)。
文摘The observations from satellite microwave sounding instruments have been proven to significantly impact severe weather monitoring and numerical weather prediction.Recent research indicates that the maturation of digitally channelized technology enables hyperspectral microwave sounding.However,the specific effects of these hyperspectral channels on the retrieval of temperature and humidity profiles remain uncertain.In this study,a novel microwave to terahertz sounder(MTS)is explored.Specifically,the impacts of 50–60 GHz(V band)hyperspectral channels and380–420 GHz(Y1 and Y2 band)terahertz channels on one-dimensional variational retrieval(1DVAR)results are investigated through various channel configurations.Initially,the information entropy of the channels is evaluated.When compared to the currently orbiting microwave sounders,the use of V-band hyperspectral channels can reduce the root-mean-square error(RMSE)of the retrieved temperature near the tropopause by approximately 14%.The inclusion of Y1 and Y2 band channels also positively contributes to the retrieved profiles.Compared to the currently deployed microwave sounders,this leads to a 2%reduction in temperature RMSE and a 5%reduction in humidity RMSE.The optimal channel configuration based on information entropy results in a temperature RMSE reduction of around 5.6%and a humidity RMSE reduction of 4.1%.Furthermore,the influence of observation noises on the retrieval results is examined.It is discovered that halving the noise can decrease the temperature RMSE by 13%and the humidity RMSE by 6%.Overall,the new sounding channels offer greater potential for enhancing temperature and humidity sounding,and they may potentially improve atmospheric measurements and the utilization of microwave observations in numerical weather prediction.
基金Supported by the National Natural Science Foundation of China(41930972)。
文摘Tropical cyclones(TCs),including tropical depressions and different categories of typhoons,hurricanes,and cyclonic storms,mostly originate over the oceans in the absence of direct observations.Thus,detailed monitoring and analysis of TCs has always been an unsolved problem.In the recent 20 years,great changes have taken place in domestic and foreign TC monitoring techniques,imposing a significant impact on TC operations and research.Some new technologies and products gradually emerge to support operations,with improved monitoring accuracy.In this paper,the progress on TC monitoring and analysis via meteorological satellites,radars,and airplanes in China and the world is reviewed,compared,and summarized,with special focuses on multisatellite fusion observations,in situ aircraft measurements,and some unconventional observation equipment such as rockets,saildrones,and underwater gliders.On this basis,the paper points out future directions for improving TC monitoring and analysis in aid of better TC forecast and early warning.
