Summer precipitation in the Three Rivers Source Region(TRSR)of China is vital for the headwaters of the Yellow,Yangtze,and Lancang rivers and exhibits significant interdecadal variability.This study investigates the i...Summer precipitation in the Three Rivers Source Region(TRSR)of China is vital for the headwaters of the Yellow,Yangtze,and Lancang rivers and exhibits significant interdecadal variability.This study investigates the influence of the East Asian westerly jet(EAWJ)on TRSR rainfall.A strong correlation is found between TRSR summer precipitation and the Jet Zonal Position Index(JZPI)of the EAWJ from 1961 to 2019(R=0.619,p<0.01).During periods when a positive JZPI indicates a westward shift in the EAWJ,enhanced water vapor anomalies,warmer air,and low-level convergence anomalies contribute to increased TRSR summer precipitation.Using empirical orthogonal function and regression analyses,this research identifies the influence of large-scale circulation anomalies associated with the Atlantic–Eurasian teleconnection(AEA)from the North Atlantic(NA).The interdecadal variability between the NA and central tropical Pacific(CTP)significantly affects TRSR precipitation.This influence is mediated through the AEA via a Rossby wave train extending eastward along the EAWJ,and another south of 45°N.Moreover,the NA–CTP Opposite Phase Index(OPI),which quantifies the difference between the summer mean sea surface temperatures of the NA and the CTP,is identified as a critical factor in modulating the strength of this teleconnection and influencing the zonal position of the EAWJ.展开更多
The interannual meridional displacement of the upper-tropospheric westerly jet over the eastern portion of East Asia in summer has been well documented.This study,however,investigates the interannual meridional displa...The interannual meridional displacement of the upper-tropospheric westerly jet over the eastern portion of East Asia in summer has been well documented.This study,however,investigates the interannual meridional displacement of the westerly jet over the western portion of East Asia in summer,which is distinct from its eastern counterpart.The results show that the meridional displacement of the western East Asian jet shows a clear asymmetric feature;that is,there are remarkable differences between the southward and northward displacement of the jet.The southward displacement of the jet corresponds to suppressed convection in the tropical western North Pacific and Maritime Continent and enhanced convection in the equatorial Pacific,which can be explained by the warmer sea surfaces found in the northern Indian Ocean and equatorial eastern Pacific.These tropical anomalies somewhat resemble those associated with the eastern East Asian jet variability.However,the northward displacement of the western East Asian jet does not correspond to significant convection and SST anomalies in the entire tropics;instead,the northward displacement of the jet corresponds well to the positive phase of the Arctic Oscillation.Furthermore,the meridional displacement of the western jet has asymmetric impacts on rainfall and surface air temperatures in East Asia.When the western jet shifts northward,more precipitation is found over South China and Northeast China,and higher temperatures appear in northern China.By contrast,when the jet shifts southward,more precipitation appears over the East Asian rainy belt,including the Yangtze River valley,South Korea,and southern and central Japan and warmer temperatures are found South and Southeast Asia.展开更多
Three-dimensional unmanned aerial vehicle(UAV)oblique photogrammetric data were used to infer mountainous gravel braided river lithofacies,lithofacies associations and architectural elements.Hierarchical architecture ...Three-dimensional unmanned aerial vehicle(UAV)oblique photogrammetric data were used to infer mountainous gravel braided river lithofacies,lithofacies associations and architectural elements.Hierarchical architecture and lithofacies associations with detailed lithofacies characterizations were comprehensively described to document the architectural model,architectural element scale and gravel particle scale.(1)Nine lithofacies(i.e.,Gmm,Gcm,Gcc,Gci,Gcl,Ss,Sm,Fsm and Fl)were identified and classified as gravel,sand and fine matrix deposits.These are typical depositional features of a mountainous dryland gravel-braided river.(2)Three architectural elements were identified,including channel(CH),gravel bar(GB)and overbank(OB).CH can be further divided into flow channel and abandoned channel,while GB consists of Central Gravel bar(CGB)and Margin Gravel bar(MGB).(3)The gravel bar is the key architectural element of the gravel braided river,with its geological attributes.The dimensions of GBs and their particles are various,but exhibit good relationships with each other.The grain size of GB decreases downstream,but the dimensions of GB do not.The bank erosion affects the GB dimensions,whereas channel incision and water flow velocity influence the grain size of GB.The conclusions can be applied to the dryland gravel braided river studies in tectonically active areas.展开更多
The Xiaobaishitou gabbro-diorite pluton comprises a medium-grained gabbro-diorite suite and a fine-grained diorite suite,which intrude the Kawabulag Group in the East Tianshan Orogen of the Central Asian Orogenic Belt...The Xiaobaishitou gabbro-diorite pluton comprises a medium-grained gabbro-diorite suite and a fine-grained diorite suite,which intrude the Kawabulag Group in the East Tianshan Orogen of the Central Asian Orogenic Belt(CAOB).A combination of mineral chemistry,zircon U-Pb age,whole-rock geochemistry,Sr-Nd isotopes,and in situ zircon Hf isotopes for newly found gabbro-diorite from the Xiaobaishitou district in the Central Tianshan Terrane(CTT)is presented to investigate the petrogenesis and tectonic or even crustal evolution of the East Tianshan Orogen.Laser ablation inductively coupled plasma mass spectrometry(LA-ICP-MS)zircon U-Pb analyses indicate that the gabbro-diorite was formed at 324.7±2.4 Ma.The isolated clinopyroxene formed under higher P-T-fO_(2)melt conditions(10.7–14.6 kbar;1199–1269℃;high fO_(2))than those for the hornblende,plagioclase,and zircon(557–687℃;moderate fO_(2))in the gabbro-diorite,which reveals a multilevel,magmatic storage system.The gabbro-diorite is characterized by fractioned REE patterns,enriched LILEs(e.g.,Ba and Pb),negative anomalies of HFSEs(e.g.,Nb and Ta),and low La/Yb and Sr/Y ratios,which are typically indicative of crustal contamination and accounted for by subduction-related fluids.The rock also characterized by typical features of high compatible elements(MgO=3.14–11.65 wt%,Cr=1–157 ppm,Ni=6–830 ppm),high Mg^(#)(47–74),positiveε_(Hf)(t)values(+5.1 to+10.3)andε_(Nd)(t)values(+2.3 to+4.4).These features suggest that the Xiaobaishitou gabbro-diorite was most likely derived from metasomatic mantle and contaminated minor crustal components.Taking into account the spatial and temporal distribution of the Carboniferous magmatic rocks in the CTT,we suggest the formation of the Xiaobaishitou gabbro-diorite was attributed to southward subduction of the Kangguer Ocean.展开更多
The East China Sea(ECS)boasts a vast continental shelf,where strong tidal motions play an important role in the substance transport and energy budget.In this study,the tide-induced mixing in the bottom boundary layer ...The East China Sea(ECS)boasts a vast continental shelf,where strong tidal motions play an important role in the substance transport and energy budget.In this study,the tide-induced mixing in the bottom boundary layer in the western ECS is analyzed based on records measured by moored acoustic Doppler current profilers from June to October 2014.Results show that the M_(2) tide is strong and shows a barotropic feature,whereas the O_(1) tide is much weaker.Based on the M_(2) tidal currents,the eddy viscosity in the bottom Ekman boundary layer is estimated with three schemes.The estimated eddy viscosity values vary within 10^(-4)–10^(-2)m^(2) s^(−1),reaching a maximum at approximately 5 m height from the bottom and decreasing exponentially with the height at all three stations.Moreover,the shear production of turbulent kinetic energy is calculated to quantify the mixing induced by different tidal constituents.The results show that the shear production of the M_(2) tide is much stronger than that of the O_(1) tide and shows a bottom intensified feature.展开更多
DEAR EDITOR,Bostrychus,a genus in the family Eleotridae of the order Gobiiformes,was first established by Lacepède in 1801(Buffon,1801).Bostrychus currently contains seven recognized species,including two recent ...DEAR EDITOR,Bostrychus,a genus in the family Eleotridae of the order Gobiiformes,was first established by Lacepède in 1801(Buffon,1801).Bostrychus currently contains seven recognized species,including two recent additions(B.microphthalmos and B.scalaris)described in 2005(Hoese&Kottelat,2005)and 2008(Larson,2008),respectively.The natural range of Bostrychus species extends from East Asia to Australia,with the exception of B.africanus,Steindachner,1879,which is distributed in West Africa(Herre,1946).Among the recognized species,B.sinensis,B.zonatus,and B.africanus are relatively widespread,inhabiting diverse areas from estuaries to freshwater streams,while B.scalaris is only found at a single mangrove site in the Selangor State of Malaysia(Larson,2008).The remaining three species exhibit a high degree of habitat specialization and are highly localized(Hoese&Kottelat,2005):B.microphthalmos inhabits a cave stream in the Maros karst of southern Sulawesi,B.aruensis is confined to freshwater environments in the Aru Islands of Indonesia,and B.strigogenys is found only in freshwater areas in southern Papua New Guinea and Irian Jaya.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
Realists like e.g.Mearsheimer from University of Chicago see war between states as a game over regional hegemony.The US leading the West blocks the East in the Ukraine and in Israel as well as Taiwan.The major risk fo...Realists like e.g.Mearsheimer from University of Chicago see war between states as a game over regional hegemony.The US leading the West blocks the East in the Ukraine and in Israel as well as Taiwan.The major risk for mankind is a third new conflict,namely Taiwan.The suffering from the wars in Ukraine and Palestine is so heavy that we need to unpack the Huntington idea of civilization war.展开更多
Complex topography,special geographical location and sea-land-air interactions lead to high interannual variability of summer precipitation in the east of Southwest China(ESWC).However,the contributions,influencing fa...Complex topography,special geographical location and sea-land-air interactions lead to high interannual variability of summer precipitation in the east of Southwest China(ESWC).However,the contributions,influencing factors and mechanisms of remote and local evaporation remain to be further investigated.Using clustering analysis and Hybrid Single-Particle Lagrangian Integrated Trajectory version 5 model,we analyze the contributions of remote moisture transport and local evaporation to summer precipitation in the ESWC and their causes.There are mainly five remote moisture channels in the ESWC,namely the Arabian Sea channel,Bay of Bengal channel,western Pacific channel,Northwest channel 1 and Northwest channel 2.Among the five channels,the western Pacific channel has the largest number of trajectories,while the Bay of Bengal channel has the largest contribution rate of specific humidity(33.33%)and moisture flux(33.14%).The amount of regional average precipitation is close to that of the precipitation caused by remote moisture transport,and both are considerably greater than the rainfall amount caused by local evaporation.However,on interannual time scales,precipitation recirculation rates are negatively correlated to regional average precipitation and precipitation caused by remote moisture transport but are consistent with that caused by local evaporation.An apparent"+-+"wave train can be found on the height anomaly field in East Asia,and the sea surface temperature anomalies are positive in the equatorial Middle-East Pacific,the South China Sea,the Bay of Bengal and the Arabian Sea.These phenomena cause southwest-northeast moisture transport with strong updrafts,thereby resulting in more precipitation in the ESWC.展开更多
基金supported by the 2nd Scientific Expedition to the Qinghai–Tibet Plateau[grant number 2019QZKK0102]the National Natural Science Foundation of China[grant number 42275045,41975012]+3 种基金the West Light Foundation of the Chinese Academy of Sciences[grant number xbzg-zdsys-202215]the Science and Technology Research Plan of Gansu Province[grant number 20JR10RA070]the Youth Innovation Promotion Association of the Chinese Academy of Sciences[grant number QCH2019004]iLEAPs(integrated Land Ecosystem–Atmosphere Processes Study).
文摘Summer precipitation in the Three Rivers Source Region(TRSR)of China is vital for the headwaters of the Yellow,Yangtze,and Lancang rivers and exhibits significant interdecadal variability.This study investigates the influence of the East Asian westerly jet(EAWJ)on TRSR rainfall.A strong correlation is found between TRSR summer precipitation and the Jet Zonal Position Index(JZPI)of the EAWJ from 1961 to 2019(R=0.619,p<0.01).During periods when a positive JZPI indicates a westward shift in the EAWJ,enhanced water vapor anomalies,warmer air,and low-level convergence anomalies contribute to increased TRSR summer precipitation.Using empirical orthogonal function and regression analyses,this research identifies the influence of large-scale circulation anomalies associated with the Atlantic–Eurasian teleconnection(AEA)from the North Atlantic(NA).The interdecadal variability between the NA and central tropical Pacific(CTP)significantly affects TRSR precipitation.This influence is mediated through the AEA via a Rossby wave train extending eastward along the EAWJ,and another south of 45°N.Moreover,the NA–CTP Opposite Phase Index(OPI),which quantifies the difference between the summer mean sea surface temperatures of the NA and the CTP,is identified as a critical factor in modulating the strength of this teleconnection and influencing the zonal position of the EAWJ.
基金supported by the National Natural Science Foundation of China(Grant Nos.42130504 and 42275031)。
文摘The interannual meridional displacement of the upper-tropospheric westerly jet over the eastern portion of East Asia in summer has been well documented.This study,however,investigates the interannual meridional displacement of the westerly jet over the western portion of East Asia in summer,which is distinct from its eastern counterpart.The results show that the meridional displacement of the western East Asian jet shows a clear asymmetric feature;that is,there are remarkable differences between the southward and northward displacement of the jet.The southward displacement of the jet corresponds to suppressed convection in the tropical western North Pacific and Maritime Continent and enhanced convection in the equatorial Pacific,which can be explained by the warmer sea surfaces found in the northern Indian Ocean and equatorial eastern Pacific.These tropical anomalies somewhat resemble those associated with the eastern East Asian jet variability.However,the northward displacement of the western East Asian jet does not correspond to significant convection and SST anomalies in the entire tropics;instead,the northward displacement of the jet corresponds well to the positive phase of the Arctic Oscillation.Furthermore,the meridional displacement of the western jet has asymmetric impacts on rainfall and surface air temperatures in East Asia.When the western jet shifts northward,more precipitation is found over South China and Northeast China,and higher temperatures appear in northern China.By contrast,when the jet shifts southward,more precipitation appears over the East Asian rainy belt,including the Yangtze River valley,South Korea,and southern and central Japan and warmer temperatures are found South and Southeast Asia.
基金supported by the National Science and Technology Major Project(Grant No.2017ZX05008-006004-002)the National Natural Science Foundation of China(Grant Nos.41502126 and 41902155)the Open Foundation of Top Disciplines in Yangtze University(Grant No.2019KFJJ0818022)。
文摘Three-dimensional unmanned aerial vehicle(UAV)oblique photogrammetric data were used to infer mountainous gravel braided river lithofacies,lithofacies associations and architectural elements.Hierarchical architecture and lithofacies associations with detailed lithofacies characterizations were comprehensively described to document the architectural model,architectural element scale and gravel particle scale.(1)Nine lithofacies(i.e.,Gmm,Gcm,Gcc,Gci,Gcl,Ss,Sm,Fsm and Fl)were identified and classified as gravel,sand and fine matrix deposits.These are typical depositional features of a mountainous dryland gravel-braided river.(2)Three architectural elements were identified,including channel(CH),gravel bar(GB)and overbank(OB).CH can be further divided into flow channel and abandoned channel,while GB consists of Central Gravel bar(CGB)and Margin Gravel bar(MGB).(3)The gravel bar is the key architectural element of the gravel braided river,with its geological attributes.The dimensions of GBs and their particles are various,but exhibit good relationships with each other.The grain size of GB decreases downstream,but the dimensions of GB do not.The bank erosion affects the GB dimensions,whereas channel incision and water flow velocity influence the grain size of GB.The conclusions can be applied to the dryland gravel braided river studies in tectonically active areas.
基金supported by the National Natural Science Foundation of China Program(Grant Nos.41672072,41302074)the Third Xinjiang Scientific Expedition Program(Grant No.2021xjkk1301)。
文摘The Xiaobaishitou gabbro-diorite pluton comprises a medium-grained gabbro-diorite suite and a fine-grained diorite suite,which intrude the Kawabulag Group in the East Tianshan Orogen of the Central Asian Orogenic Belt(CAOB).A combination of mineral chemistry,zircon U-Pb age,whole-rock geochemistry,Sr-Nd isotopes,and in situ zircon Hf isotopes for newly found gabbro-diorite from the Xiaobaishitou district in the Central Tianshan Terrane(CTT)is presented to investigate the petrogenesis and tectonic or even crustal evolution of the East Tianshan Orogen.Laser ablation inductively coupled plasma mass spectrometry(LA-ICP-MS)zircon U-Pb analyses indicate that the gabbro-diorite was formed at 324.7±2.4 Ma.The isolated clinopyroxene formed under higher P-T-fO_(2)melt conditions(10.7–14.6 kbar;1199–1269℃;high fO_(2))than those for the hornblende,plagioclase,and zircon(557–687℃;moderate fO_(2))in the gabbro-diorite,which reveals a multilevel,magmatic storage system.The gabbro-diorite is characterized by fractioned REE patterns,enriched LILEs(e.g.,Ba and Pb),negative anomalies of HFSEs(e.g.,Nb and Ta),and low La/Yb and Sr/Y ratios,which are typically indicative of crustal contamination and accounted for by subduction-related fluids.The rock also characterized by typical features of high compatible elements(MgO=3.14–11.65 wt%,Cr=1–157 ppm,Ni=6–830 ppm),high Mg^(#)(47–74),positiveε_(Hf)(t)values(+5.1 to+10.3)andε_(Nd)(t)values(+2.3 to+4.4).These features suggest that the Xiaobaishitou gabbro-diorite was most likely derived from metasomatic mantle and contaminated minor crustal components.Taking into account the spatial and temporal distribution of the Carboniferous magmatic rocks in the CTT,we suggest the formation of the Xiaobaishitou gabbro-diorite was attributed to southward subduction of the Kangguer Ocean.
基金supported by the Zhejiang Provincial Natural Science Foundation of China(No.LY21D060005)the Shandong Provincial Natural Science Foundation(No.ZR2022MD082)+2 种基金the Joint Project of Zhoushan Municipality and Zhejiang University(No.2019C810060)the Open Fund Project of Key Laboratory of Marine Environmental Information Technologythe Strategic Priority Research Program of Chinese Academy of Sciences(No.XDA19060201).
文摘The East China Sea(ECS)boasts a vast continental shelf,where strong tidal motions play an important role in the substance transport and energy budget.In this study,the tide-induced mixing in the bottom boundary layer in the western ECS is analyzed based on records measured by moored acoustic Doppler current profilers from June to October 2014.Results show that the M_(2) tide is strong and shows a barotropic feature,whereas the O_(1) tide is much weaker.Based on the M_(2) tidal currents,the eddy viscosity in the bottom Ekman boundary layer is estimated with three schemes.The estimated eddy viscosity values vary within 10^(-4)–10^(-2)m^(2) s^(−1),reaching a maximum at approximately 5 m height from the bottom and decreasing exponentially with the height at all three stations.Moreover,the shear production of turbulent kinetic energy is calculated to quantify the mixing induced by different tidal constituents.The results show that the shear production of the M_(2) tide is much stronger than that of the O_(1) tide and shows a bottom intensified feature.
基金supported by the National Natural Science Foundation of China(41776143)。
文摘DEAR EDITOR,Bostrychus,a genus in the family Eleotridae of the order Gobiiformes,was first established by Lacepède in 1801(Buffon,1801).Bostrychus currently contains seven recognized species,including two recent additions(B.microphthalmos and B.scalaris)described in 2005(Hoese&Kottelat,2005)and 2008(Larson,2008),respectively.The natural range of Bostrychus species extends from East Asia to Australia,with the exception of B.africanus,Steindachner,1879,which is distributed in West Africa(Herre,1946).Among the recognized species,B.sinensis,B.zonatus,and B.africanus are relatively widespread,inhabiting diverse areas from estuaries to freshwater streams,while B.scalaris is only found at a single mangrove site in the Selangor State of Malaysia(Larson,2008).The remaining three species exhibit a high degree of habitat specialization and are highly localized(Hoese&Kottelat,2005):B.microphthalmos inhabits a cave stream in the Maros karst of southern Sulawesi,B.aruensis is confined to freshwater environments in the Aru Islands of Indonesia,and B.strigogenys is found only in freshwater areas in southern Papua New Guinea and Irian Jaya.
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Realists like e.g.Mearsheimer from University of Chicago see war between states as a game over regional hegemony.The US leading the West blocks the East in the Ukraine and in Israel as well as Taiwan.The major risk for mankind is a third new conflict,namely Taiwan.The suffering from the wars in Ukraine and Palestine is so heavy that we need to unpack the Huntington idea of civilization war.
基金National Natural Science Foundation of China(41875111)Special program for innovation and development of China Meteorological Administration(CXFZ2022J031,CXFZ2021J018)National Natural Science Foundation of China(40975058)。
文摘Complex topography,special geographical location and sea-land-air interactions lead to high interannual variability of summer precipitation in the east of Southwest China(ESWC).However,the contributions,influencing factors and mechanisms of remote and local evaporation remain to be further investigated.Using clustering analysis and Hybrid Single-Particle Lagrangian Integrated Trajectory version 5 model,we analyze the contributions of remote moisture transport and local evaporation to summer precipitation in the ESWC and their causes.There are mainly five remote moisture channels in the ESWC,namely the Arabian Sea channel,Bay of Bengal channel,western Pacific channel,Northwest channel 1 and Northwest channel 2.Among the five channels,the western Pacific channel has the largest number of trajectories,while the Bay of Bengal channel has the largest contribution rate of specific humidity(33.33%)and moisture flux(33.14%).The amount of regional average precipitation is close to that of the precipitation caused by remote moisture transport,and both are considerably greater than the rainfall amount caused by local evaporation.However,on interannual time scales,precipitation recirculation rates are negatively correlated to regional average precipitation and precipitation caused by remote moisture transport but are consistent with that caused by local evaporation.An apparent"+-+"wave train can be found on the height anomaly field in East Asia,and the sea surface temperature anomalies are positive in the equatorial Middle-East Pacific,the South China Sea,the Bay of Bengal and the Arabian Sea.These phenomena cause southwest-northeast moisture transport with strong updrafts,thereby resulting in more precipitation in the ESWC.
