In this study, we investigated the features of Arctic Oscillation （AO） and Antarctic Oscillation （AAO）, that is, the annular modes in the extratropics, in the internal atmospheric variability attained through an e...In this study, we investigated the features of Arctic Oscillation （AO） and Antarctic Oscillation （AAO）, that is, the annular modes in the extratropics, in the internal atmospheric variability attained through an ensemble of integrations by an atmospheric general circulation model （AGCM） forced with the global observed SSTs. We focused on the interannual variability of AO/AAO, which is dominated by internal atmospheric variability. In comparison with previous observed results, the AO/AAO in internal atmospheric variability bear some similar characteristics, but exhibit a much clearer spatial structure： significant correlation between the North Pacific and North Atlantic centers of action, much stronger and more significant associated precipitation anomalies, and the meridional displacement of upper-tropospheric westerly jet streams in the Northern/Southern Hemisphere. In addition, we examined the relationship between the North Atlantic Oscillation （NAO）/AO and East Asian winter monsoon （EAWM）. It has been shown that in the internal atmospheric variability, the EAWM variation is significantly related to the NAO through upper-tropospheric atmospheric teleconnection patterns.展开更多
To quantify the relative contributions of Arctic sea ice and unforced atmospheric internal variability to the “warm Arctic, cold East Asia”(WACE) teleconnection, this study analyses three sets of large-ensemble simu...To quantify the relative contributions of Arctic sea ice and unforced atmospheric internal variability to the “warm Arctic, cold East Asia”(WACE) teleconnection, this study analyses three sets of large-ensemble simulations carried out by the Norwegian Earth System Model with a coupled atmosphere–land surface model, forced by seasonal sea ice conditions from preindustrial, present-day, and future periods. Each ensemble member within the same set uses the same forcing but with small perturbations to the atmospheric initial state. Hence, the difference between the present-day(or future) ensemble mean and the preindustrial ensemble mean provides the ice-loss-induced response, while the difference of the individual members within the present-day(or future) set is the effect of atmospheric internal variability. Results indicate that both present-day and future sea ice loss can force a negative phase of the Arctic Oscillation with a WACE pattern in winter. The magnitude of ice-induced Arctic warming is over four(ten) times larger than the ice-induced East Asian cooling in the present-day(future) experiment;the latter having a magnitude that is about 30% of the observed cooling. Sea ice loss contributes about 60%(80%) to the Arctic winter warming in the present-day(future) experiment. Atmospheric internal variability can also induce a WACE pattern with comparable magnitudes between the Arctic and East Asia. Ice-lossinduced East Asian cooling can easily be masked by atmospheric internal variability effects because random atmospheric internal variability may induce a larger magnitude warming. The observed WACE pattern occurs as a result of both Arctic sea ice loss and atmospheric internal variability, with the former dominating Arctic warming and the latter dominating East Asian cooling.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
The variations of the marine atmospheric boundary layer (MABL) associated with the South China Sea Summer Monsoon were examined using the Global Positioning System (GPS) sounding datasets obtained four times daily dur...The variations of the marine atmospheric boundary layer (MABL) associated with the South China Sea Summer Monsoon were examined using the Global Positioning System (GPS) sounding datasets obtained four times daily during May-June 1998 on board Research Vessels Kexue 1 and Shiyan 3. The MABL height is defined as the height at the lowest level where virtual potential temperature increases by 1 K from the surface. The results indicate that the MABL height decreased over the northern South China Sea (SCS) and remained the same over the southern SCS, as sea surface temperature (SST) fell for the northern and rose for the southern SCS after the monsoon onset. Over the northern SCS, a decrease in both the SST and the surface latent-heat flux after the onset resulted in a reduction of the MABL height as well as a decoupling of MABL from clouds. It was found that MABL height reduction corresponded to rainfall occurrence. Over the southern SCS, a probable reason for the constant increase of SST and surface heat flux was the rainfall and internal atmospheric dynamics.展开更多
1.Introduction Spectacular advances have been made in the atmospheric sciences on a global level during a period of one hundred years or more,which is arguably most evident through"the quiet revolution of numeric...1.Introduction Spectacular advances have been made in the atmospheric sciences on a global level during a period of one hundred years or more,which is arguably most evident through"the quiet revolution of numerical weather prediction"(Bauer et展开更多
The study of internal atmospheric waves,also known as gravity waves,which are detectable inside the fluid rather than at the fluid surface,is presented in this work.We have used the time-fractional and fuzzy-fractiona...The study of internal atmospheric waves,also known as gravity waves,which are detectable inside the fluid rather than at the fluid surface,is presented in this work.We have used the time-fractional and fuzzy-fractional techniques to solve the differential equation system representing the atmospheric inter-nal waves model.The q-Homotopy analysis Shehu transform technique(q-HAShTM)is used to solve the model.The method helps find convergent solutions since it helps solve nonlinearity,and the fractional derivative can be easily computed using the Shehu transform.Finally,the obtained solution is compared for the particular case ofα=1 with the HAM solution to explain the method’s accuracy.展开更多
A theoretical model was used to investigate the influences of environmental and topographic parameters on the atmospheric three-layer internal ship waves. The results show that both the wavelength and the wedge angle ...A theoretical model was used to investigate the influences of environmental and topographic parameters on the atmospheric three-layer internal ship waves. The results show that both the wavelength and the wedge angle decrease with an increase in the Scorer parameter, and the rate of changes in the wavelength and wedge angle are also alike. The results also show that the wedge angle decreases with an increase in the width of mountain, but the wavelength varies little with it. It is suggested that the wedge angle is determined by the ratio of the wavelength to the scale of the mountain. Besides, numerical sensitivity experiments were performed to test the former numerical experiments. The simulated results are consistent with the analytical results.展开更多
This study looks at the mathematical model of internal atmospheric waves,often known as gravity waves,occurring inside a fluid rather than on the surface.Under the shallow-fluid assumption,internal atmospheric waves m...This study looks at the mathematical model of internal atmospheric waves,often known as gravity waves,occurring inside a fluid rather than on the surface.Under the shallow-fluid assumption,internal atmospheric waves may be described by a nonlinear partial differential equation system.The shallow flow model’s primary concept is that the waves are spread out across a large horizontal area before rising vertically.The Fractional Reduced Differential Transform Method(FRDTM)is applied to provide approximate solutions for any given model.This aids in the modelling of the global atmosphere,which has applications in weather and climate forecasting.For the integer-order value(α=1),the FRDTM solution is compared to the precise solution,EADM,and HAM to assess the correctness and efficacy of the proposed technique.展开更多
This article involves the study of atmospheric internal waves phenomenon,also referred to as gravity waves.This phenomenon occurs inside the fluid,not on the surface.The model is based on a shallow fluid hypothesis re...This article involves the study of atmospheric internal waves phenomenon,also referred to as gravity waves.This phenomenon occurs inside the fluid,not on the surface.The model is based on a shallow fluid hypothesis represented by a system of nonlinear partial differential equations.The basic assumption of the shallow flow model is that the horizontal size is much larger than the vertical size.Atmospheric internal waves can be perfectly represented by this model as the waves are spread over a large horizontal area.Here we used the Elzaki Adomian Decomposition Method(EADM)to obtain the solution for the considered model along with its convergence analysis.The Adomian decomposition method together with the Elzaki transform gives the solution in a convergent series without any linearization or perturbation.Comparisons are built between the results obtained by EADM and HAM to examine the accuracy of the proposed method.展开更多
The East Asian monsoon transitional zone(MTZ)is a northeast-southwest oriented belt between the wet monsoon areas and the northwestern dry areas of China with a fragile ecology and high climate sensitivity.The climate...The East Asian monsoon transitional zone(MTZ)is a northeast-southwest oriented belt between the wet monsoon areas and the northwestern dry areas of China with a fragile ecology and high climate sensitivity.The climate in the MTZ is characterized by strong instability and large variability,resulting in frequent occurrence of extreme weather and climate events.A number of studies have focused on the dry-wet characteristics from different perspectives,taking into account the increasing problems of water scarcity and ecological risks.This study reviews the multi-scale variations,underlying mechanisms and future projections of dry-wet conditions over the MTZ under global warming.The main findings over the last few decades are summarized as follows:1)the interannual variability of summer precipitation is under the combined impacts of oceanic forcings and internal atmospheric teleconnection patterns at mid-high latitudes;2)an interdecadal decrease in summer precipitation amount in the MTZ was observed in the late 1990s due to a Silk-Road pattern-like wave train triggered by the combined impacts of the Atlantic Multidecadal Oscillation-like SST warming over the North Atlantic and positive-to-negative phase shift of the Pacific Decadal Oscillation(PDO);3)a pronounced drying trend has been observed during 1951-2005,which is mainly attributed to human activities and internal atmospheric variability,including increased aerosols,land-use changes,thermal forcing over the Tibetan Plateau,and the phase shift of the PDO;and 4)the summer precipitation in the MTZ is projected to increase under global warming with considerable uncertainties mainly due to internal atmospheric variability,including the Arctic Oscillation and the Polar-Eurasian pattern.This review attempts to provide a clear and systematic picture on the distinctive changing features of dry-wet conditions over the MTZ,and to attract the interest of the scientific community in climate change over this unique“transition”domain.展开更多
What is the flight level in aviation?In aviation,a flight level(FL)is an aircraft's altitude as determined by a pressure altimeter using the International Standard Atmosphere.It is expressed in hundreds of feet or...What is the flight level in aviation?In aviation,a flight level(FL)is an aircraft's altitude as determined by a pressure altimeter using the International Standard Atmosphere.It is expressed in hundreds of feet or metres.The altimeter seting used is the ISA sea level pressure of 1,013 hPa or 29.92 inHg.展开更多
基金This work is supported by the National Natural Science Foundation of China(Grant Nos.40475025 and 40221503)Buwen Dong was supported by the ENSEMBLES Project(GOCE-CT-2003-505539)at the UK Natural Environmental Research Council Centres for Atmospheric Science.
文摘In this study, we investigated the features of Arctic Oscillation （AO） and Antarctic Oscillation （AAO）, that is, the annular modes in the extratropics, in the internal atmospheric variability attained through an ensemble of integrations by an atmospheric general circulation model （AGCM） forced with the global observed SSTs. We focused on the interannual variability of AO/AAO, which is dominated by internal atmospheric variability. In comparison with previous observed results, the AO/AAO in internal atmospheric variability bear some similar characteristics, but exhibit a much clearer spatial structure： significant correlation between the North Pacific and North Atlantic centers of action, much stronger and more significant associated precipitation anomalies, and the meridional displacement of upper-tropospheric westerly jet streams in the Northern/Southern Hemisphere. In addition, we examined the relationship between the North Atlantic Oscillation （NAO）/AO and East Asian winter monsoon （EAWM）. It has been shown that in the internal atmospheric variability, the EAWM variation is significantly related to the NAO through upper-tropospheric atmospheric teleconnection patterns.
基金supported by the Chinese-Norwegian Collaboration Projects within Climate Systems jointly funded by the National Key Research and Development Program of China (Grant No.2022YFE0106800)the Research Council of Norway funded project MAPARC (Grant No.328943)+2 种基金the support from the Research Council of Norway funded project BASIC (Grant No.325440)the Horizon 2020 project APPLICATE (Grant No.727862)High-performance computing and storage resources were performed on resources provided by Sigma2 - the National Infrastructure for High-Performance Computing and Data Storage in Norway (through projects NS8121K,NN8121K,NN2345K,NS2345K,NS9560K,NS9252K,and NS9034K)。
文摘To quantify the relative contributions of Arctic sea ice and unforced atmospheric internal variability to the “warm Arctic, cold East Asia”(WACE) teleconnection, this study analyses three sets of large-ensemble simulations carried out by the Norwegian Earth System Model with a coupled atmosphere–land surface model, forced by seasonal sea ice conditions from preindustrial, present-day, and future periods. Each ensemble member within the same set uses the same forcing but with small perturbations to the atmospheric initial state. Hence, the difference between the present-day(or future) ensemble mean and the preindustrial ensemble mean provides the ice-loss-induced response, while the difference of the individual members within the present-day(or future) set is the effect of atmospheric internal variability. Results indicate that both present-day and future sea ice loss can force a negative phase of the Arctic Oscillation with a WACE pattern in winter. The magnitude of ice-induced Arctic warming is over four(ten) times larger than the ice-induced East Asian cooling in the present-day(future) experiment;the latter having a magnitude that is about 30% of the observed cooling. Sea ice loss contributes about 60%(80%) to the Arctic winter warming in the present-day(future) experiment. Atmospheric internal variability can also induce a WACE pattern with comparable magnitudes between the Arctic and East Asia. Ice-lossinduced East Asian cooling can easily be masked by atmospheric internal variability effects because random atmospheric internal variability may induce a larger magnitude warming. The observed WACE pattern occurs as a result of both Arctic sea ice loss and atmospheric internal variability, with the former dominating Arctic warming and the latter dominating East Asian cooling.
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supported by the Chinese Academy of Sciences (Grant No. KZCX1-YW-12-01)the National Natural Science Foundation of China (Grant Nos. U0733002 and 40876009)The National Basic Research Program of China (Grant No. 2011CB403504)
文摘The variations of the marine atmospheric boundary layer (MABL) associated with the South China Sea Summer Monsoon were examined using the Global Positioning System (GPS) sounding datasets obtained four times daily during May-June 1998 on board Research Vessels Kexue 1 and Shiyan 3. The MABL height is defined as the height at the lowest level where virtual potential temperature increases by 1 K from the surface. The results indicate that the MABL height decreased over the northern South China Sea (SCS) and remained the same over the southern SCS, as sea surface temperature (SST) fell for the northern and rose for the southern SCS after the monsoon onset. Over the northern SCS, a decrease in both the SST and the surface latent-heat flux after the onset resulted in a reduction of the MABL height as well as a decoupling of MABL from clouds. It was found that MABL height reduction corresponded to rainfall occurrence. Over the southern SCS, a probable reason for the constant increase of SST and surface heat flux was the rainfall and internal atmospheric dynamics.
基金Support for this study was provided by the “Waves to Weather” initiative (SFB/TRR 165) of the German Research Foundation (DFG)
文摘1.Introduction Spectacular advances have been made in the atmospheric sciences on a global level during a period of one hundred years or more,which is arguably most evident through"the quiet revolution of numerical weather prediction"(Bauer et
文摘The study of internal atmospheric waves,also known as gravity waves,which are detectable inside the fluid rather than at the fluid surface,is presented in this work.We have used the time-fractional and fuzzy-fractional techniques to solve the differential equation system representing the atmospheric inter-nal waves model.The q-Homotopy analysis Shehu transform technique(q-HAShTM)is used to solve the model.The method helps find convergent solutions since it helps solve nonlinearity,and the fractional derivative can be easily computed using the Shehu transform.Finally,the obtained solution is compared for the particular case ofα=1 with the HAM solution to explain the method’s accuracy.
基金the National Natural Science Foundation of China (Grant No. 40705020)the OpeningFoundation of LASG
文摘A theoretical model was used to investigate the influences of environmental and topographic parameters on the atmospheric three-layer internal ship waves. The results show that both the wavelength and the wedge angle decrease with an increase in the Scorer parameter, and the rate of changes in the wavelength and wedge angle are also alike. The results also show that the wedge angle decreases with an increase in the width of mountain, but the wavelength varies little with it. It is suggested that the wedge angle is determined by the ratio of the wavelength to the scale of the mountain. Besides, numerical sensitivity experiments were performed to test the former numerical experiments. The simulated results are consistent with the analytical results.
文摘This study looks at the mathematical model of internal atmospheric waves,often known as gravity waves,occurring inside a fluid rather than on the surface.Under the shallow-fluid assumption,internal atmospheric waves may be described by a nonlinear partial differential equation system.The shallow flow model’s primary concept is that the waves are spread out across a large horizontal area before rising vertically.The Fractional Reduced Differential Transform Method(FRDTM)is applied to provide approximate solutions for any given model.This aids in the modelling of the global atmosphere,which has applications in weather and climate forecasting.For the integer-order value(α=1),the FRDTM solution is compared to the precise solution,EADM,and HAM to assess the correctness and efficacy of the proposed technique.
文摘This article involves the study of atmospheric internal waves phenomenon,also referred to as gravity waves.This phenomenon occurs inside the fluid,not on the surface.The model is based on a shallow fluid hypothesis represented by a system of nonlinear partial differential equations.The basic assumption of the shallow flow model is that the horizontal size is much larger than the vertical size.Atmospheric internal waves can be perfectly represented by this model as the waves are spread over a large horizontal area.Here we used the Elzaki Adomian Decomposition Method(EADM)to obtain the solution for the considered model along with its convergence analysis.The Adomian decomposition method together with the Elzaki transform gives the solution in a convergent series without any linearization or perturbation.Comparisons are built between the results obtained by EADM and HAM to examine the accuracy of the proposed method.
基金supported by the National Natural Science Foundation of China(42230605 and 42205021).
文摘The East Asian monsoon transitional zone(MTZ)is a northeast-southwest oriented belt between the wet monsoon areas and the northwestern dry areas of China with a fragile ecology and high climate sensitivity.The climate in the MTZ is characterized by strong instability and large variability,resulting in frequent occurrence of extreme weather and climate events.A number of studies have focused on the dry-wet characteristics from different perspectives,taking into account the increasing problems of water scarcity and ecological risks.This study reviews the multi-scale variations,underlying mechanisms and future projections of dry-wet conditions over the MTZ under global warming.The main findings over the last few decades are summarized as follows:1)the interannual variability of summer precipitation is under the combined impacts of oceanic forcings and internal atmospheric teleconnection patterns at mid-high latitudes;2)an interdecadal decrease in summer precipitation amount in the MTZ was observed in the late 1990s due to a Silk-Road pattern-like wave train triggered by the combined impacts of the Atlantic Multidecadal Oscillation-like SST warming over the North Atlantic and positive-to-negative phase shift of the Pacific Decadal Oscillation(PDO);3)a pronounced drying trend has been observed during 1951-2005,which is mainly attributed to human activities and internal atmospheric variability,including increased aerosols,land-use changes,thermal forcing over the Tibetan Plateau,and the phase shift of the PDO;and 4)the summer precipitation in the MTZ is projected to increase under global warming with considerable uncertainties mainly due to internal atmospheric variability,including the Arctic Oscillation and the Polar-Eurasian pattern.This review attempts to provide a clear and systematic picture on the distinctive changing features of dry-wet conditions over the MTZ,and to attract the interest of the scientific community in climate change over this unique“transition”domain.
文摘What is the flight level in aviation?In aviation,a flight level(FL)is an aircraft's altitude as determined by a pressure altimeter using the International Standard Atmosphere.It is expressed in hundreds of feet or metres.The altimeter seting used is the ISA sea level pressure of 1,013 hPa or 29.92 inHg.
