This study identifies break events of the South China Sea(SCS)summer monsoon(SCSSM)based on 42 years of data from 1979 to 2020,and investigates their statistical characteristics and associated atmospheric anomalies.A ...This study identifies break events of the South China Sea(SCS)summer monsoon(SCSSM)based on 42 years of data from 1979 to 2020,and investigates their statistical characteristics and associated atmospheric anomalies.A total of 214 break events are identified by examining the convection evolution during each monsoon season.It is found that most events occur between June and September and show a roughly even distribution.Short-lived events(3–7 days)are more frequent,accounting for about two thirds of total events,with the residual one third for long-lived events(8–24 days).The SCSSM break is featured by drastic variations in various atmospheric variables.Particularly,the convection and precipitation change from anomalous enhancement in adjoining periods to a substantial suppression during the break,with the differences being more than 60 W m−2 for outgoing longwave radiation(OLR)and 10 mm d−1 for precipitation.This convection/precipitation suppression is accompanied by an anomalous anticyclone in the lower troposphere,corresponding to a remarkable westward retreat of the monsoon trough from the Philippine Sea to the Indochina Peninsula,which reduces the transportation of water vapor into the SCS.Besides,the pseudo-equivalent potential temperature()declines sharply,mainly attributable to the local specific humidity reduction caused by downward dry advection.Furthermore,it is found that the suppressed convection and anomalous anticyclone responsible for the monsoon break form near the equatorial western Pacific and then propagate northwestward to the SCS.展开更多
Biogeographical barriers to gene flow are central to plant phylogeography.In East Asia,plant distribution is greatly influenced by two phylogeographic breaks,the Mekong-Salween Divide and Tanaka-Kaiyong Line,however,f...Biogeographical barriers to gene flow are central to plant phylogeography.In East Asia,plant distribution is greatly influenced by two phylogeographic breaks,the Mekong-Salween Divide and Tanaka-Kaiyong Line,however,few studies have investigated how these barriers affect the genetic diversity of species that are distributed across both.Here we used 14 microsatellite loci and four chloroplast DNA fragments to examine genetic diversity and distribution patterns of 49 populations of Populus rotundifolia,a species that spans both the Mekong-Salween Divide and the Tanaka-Kaiyong Line in southwestern China.Demographic and migration hypotheses were tested using coalescent-based approaches.Limited historical gene flow was observed between the western and eastern groups of P.rotundifolia,but substantial flow occurred across both the Mekong-Salween Divide and Tanaka-Kaiyong Line,manifesting in clear admixture and high genetic diversity in the central group.Wind-borne pollen and seeds may have facilitated the dispersal of P.rotundifolia following prevalent northwest winds in the spring.We also found that the Hengduan Mountains,where multiple genetic barriers were detected,acted on the whole as a barrier between the western and eastern groups of P.rotundifolia.Ecological niche modeling suggested that P.rotundifolia has undergone range expansion since the last glacial maximum,and demographic reconstruction indicated an earlier population expansion around 600 Ka.The phylogeographic pattern of P.rotundifolia reflects the interplay of biological traits,wind patterns,barriers,niche differentiation,and Quaternary climate history.This study emphasizes the need for multiple lines of evidence in understanding the Quaternary evolution of plants in topographically complex areas.展开更多
A submerged cavitation water jet(SCWJ)is an effective method to recycle solid propellant from obsolete solid engines by the breaking method.Solid propellant's breaking modes and mechanical process under SCWJ impac...A submerged cavitation water jet(SCWJ)is an effective method to recycle solid propellant from obsolete solid engines by the breaking method.Solid propellant's breaking modes and mechanical process under SCWJ impact are unclear.This study aims to understand those impact breaking mechanisms.The hydroxyl-terminated polybutadiene(HTPB)propellant was chosen as the research material,and a self-designed test system was used to conduct impact tests at four different working pressures.The high-speed camera characterized crack propagation,and the DIC method calculated strain change during the impact process.Besides,micro and macro fracture morphologies were characterized by scanning electron microscope(SEM)and computed tomography(CT)scanning.The results reveal that the compressive strain concentration region locates right below the nozzle,and the shear strain region distributes symmetrically with the jet axis,which increases to 4% at first 16th ms,the compressive strain rises to 2% and 6% in the axial and transverse direction,respectively.The two tensile cracks formed first at the compression strain concentrate region,and there generate many shear cracks around the tensile cracks,and those shear cracks that develop and aggregate cause the cracks to become wider and cut through the tensile cracks,forming the tensile-shear cracks and the impact parts eventually fail.The HTPB propellant forms a breaking hole shaped conical after impact 10 s.The mass loss increases by 17 times at maximum,with the working pressure increasing by three times.Meanwhile,the damage value of the breaking hole remaining on the surface increases by 7.8 times while 2.9 times in the depth of the breaking hole.The breaking efficiency is closely affected by working pressures.The failure modes of HTPB impacted by SCWJ are classified as tensile crack-dominated and tensile-shear crack-dominated damage mechanisms.展开更多
The isotope composition in precipitation has been widely considered as a tracer of monsoon activity.Compared with the coastal region,the monsoon margin usually has limited precipitation with large fluctuation and is u...The isotope composition in precipitation has been widely considered as a tracer of monsoon activity.Compared with the coastal region,the monsoon margin usually has limited precipitation with large fluctuation and is usually sensitive to climate change.The water resource management in the monsoon margin should be better planned by understanding the composition of precipitation isotope and its influencing factors.In this study,the precipitation samples were collected at five sampling sites(Baiyin City,Kongtong District,Maqu County,Wudu District,and Yinchuan City)of the monsoon margin in the northwest of China in 2022 to analyze the characteristics of stable hydrogen(δD)and oxygen(δ18O)isotopes.We analyzed the impact of meteorological factors(temperature,precipitation,and relative humidity)on the composition of precipitation isotope at daily level by regression analysis,utilized the Hybrid Single-Particle Lagrangian Integrated Trajectory(HYSPLIT)-based backward trajectory model to simulate the air mass trajectory of precipitation events,and adopted the potential source contribution function(PSCF)and concentration weighted trajectory(CWT)to analyze the water vapor sources.The results showed that compared with the global meteoric water line(GMWL),the slope of the local meteoric water line(LMWL;δD=7.34δ^(18)O-1.16)was lower,indicating the existence of strong regional evaporation in the study area.Temperature significantly contributed toδ18O value,while relative humidity had a significant negative effect onδ18O value.Through the backward trajectory analysis,we found eight primary locations that were responsible for the water vapor sources of precipitation in the study area,of which moisture from the Indian Ocean to South China Sea(ITSC)and the western continental(CW)had the greatest influence on precipitation in the study area.The hydrogen and oxygen isotopes in precipitation are significantly influenced by the sources and transportation paths of air mass.In addition,the results of PSCF and CWT analysis showed that the water vapor source areas were primarily distributed in the south and northwest direction of the study area.展开更多
The West African Monsoon (WAM) is characterized by strong decadal and multi-decadal variability and the impacts can be catastrophic for the local populations. One of the factors put forward to explain this variability...The West African Monsoon (WAM) is characterized by strong decadal and multi-decadal variability and the impacts can be catastrophic for the local populations. One of the factors put forward to explain this variability involves the role of atmospheric dynamics, linked in particular to the Saharan Heat Low (SHL). This article addresses this question by comparing the sets of preindustrial control and historical simulation data from climate models carried out in the framework of the CMIP5 project and observations data over the 20<sup>th</sup> century. Through multivariate statistical analyses, it was established that decadal modes of ocean variability and decadal variability of Saharan atmospheric dynamics significantly influence decadal variability of monsoon precipitation. These results also suggest the existence of external anthropogenic forcing, which is superimposed on the decadal natural variability inducing an intensification of the signal in the historical simulations compared to preindustrial control simulations. We have also shown that decadal rainfall variability in the Sahel, once the influence of oceanic modes has been eliminated, appears to be driven mainly by the activity of the Arabian Heat Low (AHL) in the central Sahel, and by the structure of the meridional temperature gradient over the inter-tropical Atlantic in the western Sahel.展开更多
During the summer monsoon season, strong coastal upwelling occurs along the southwest coast of India and at the southern tip of India, which cools the surface temperature of the waters around these regions. The summer...During the summer monsoon season, strong coastal upwelling occurs along the southwest coast of India and at the southern tip of India, which cools the surface temperature of the waters around these regions. The summer monsoon current carries the upwelled cold waters into the Bay of Bengal and forms the ‘cold pool of the Bay of Bengal', with its core south of Sri Lanka and over the southcentral Bay of Bengal. The present study focuses on the intrusion of these cold waters into the south of the Bay of Bengal, its interannual variability, and its association with the surface wind during the break phase of the summer monsoon, when strong westerly surface winds flow south of 10°N.The authors hypothesize that the enhanced cooling in the cold pool region during monsoon spells is associated with the strong westerly wind stress there during the break spells of the monsoon.Seven cases of long break monsoon spells that occurred during the nine years from 2001 to 2009 are analyzed, and the results confirm our hypothesis.展开更多
Using a low-order spectral model derived from the equatorial equilibrium model, possible physical mechanisms are interpreted by the theory of multiple equilibria states for the active and break phases of the South Asi...Using a low-order spectral model derived from the equatorial equilibrium model, possible physical mechanisms are interpreted by the theory of multiple equilibria states for the active and break phases of the South Asian Monsoon, with consideration of the effects of heating by cumulus heating and cooling by radiation. The result shows that the South Asian Monsoon is active when the cumulus convection intensifies (or the radiation cooling weakens). the monsoon breaks when the convection weakens (or the cooling intensifies). It is consistent with the hypothesis of cloud-radiation by Krishnamurti et al.展开更多
Global Positioning System(GPS)measurements of integrated water vapor(IWV)for two years(2014 and 2015)are presented in this paper.Variation of IWV during active and break spells of Indian summer monsoon has been studie...Global Positioning System(GPS)measurements of integrated water vapor(IWV)for two years(2014 and 2015)are presented in this paper.Variation of IWV during active and break spells of Indian summer monsoon has been studied for a tropical station Hyderabad(17.4°N,78.46°E).The data is validated with ECMWF Re-Analysis(ERA)91 level data.Relationships of IWV with other atmospheric variables like surface temperature,rain,and precipitation efficiency have been established through cross-correlation studies.A positive correlation coefficient is observed between IWV and surface temperature over two years.But the coefficient becomes negative when only summer monsoon months(June,July,August,and September)are considered.Rainfall during these months cools down the surface and could be the reason for this change in the correlation coefficient.Correlation studies between IWV-precipitation,IWVprecipitation efficiency(P.E),and precipitation-P.E show that coefficients are-0.05,-0.10 and 0.983 with 95%confidence level respectively,which proves that the efficacy of rain does not depend only on the level of water vapor.A proper dynamic mechanism is necessary to convert water vapor into the rain.The diurnal variations of IWV during active and break spells have been analyzed.The amplitudes of diurnal oscillation and its harmonics of individual spell do not show clear trends but the mean amplitudes of the break spells are approximately double than those of the active spells.The amplitudes of diurnal,semidiurnal and ter-diurnal components during break spells are 1.08 kg/m^(2),0.52 kg/m;and 0.34 kg/m;respectively.The corresponding amplitudes during active spells are 0.68 kg/m^(2),0.41 kg/m;and 0.23 kg/m;.展开更多
Studies of the multi-scale climate variability of the Asian monsoon are essential to an advanced understanding of the physical processes of the global climate system.In this paper,the progress achieved in this field i...Studies of the multi-scale climate variability of the Asian monsoon are essential to an advanced understanding of the physical processes of the global climate system.In this paper,the progress achieved in this field is systematically reviewed,with a focus on the past several years.The achievements are summarized into the following topics:(1)the onset of the South China Sea summer monsoon;(2)the East Asian summer monsoon;(3)the East Asian winter monsoon;and(4)the Indian summer monsoon.Specifically,new results are highlighted,including the advanced or delayed local monsoon onset tending to be synchronized over the Arabian Sea,Bay of Bengal,Indochina Peninsula,and South China Sea;the basic features of the record-breaking mei-yu in 2020,which have been extensively investigated with an emphasis on the role of multi-scale processes;the recovery of the East Asian winter monsoon intensity after the early 2000s in the presence of continuing greenhouse gas emissions,which is believed to have been dominated by internal climate variability(mostly the Arctic Oscillation);and the accelerated warming over South Asia,which exceeded the tropical Indian Ocean warming,is considered to be the main driver of the Indian summer monsoon rainfall recovery since 1999.A brief summary is provided in the final section along with some further discussion on future research directions regarding our understanding of the Asian monsoon variability.展开更多
The South China Sea summer monsoon is an important system affecting the weather and climate in China;its outbreak and evolution vary from year to year.Using the reanalysis data from the U.S.National Centers for Enviro...The South China Sea summer monsoon is an important system affecting the weather and climate in China;its outbreak and evolution vary from year to year.Using the reanalysis data from the U.S.National Centers for Environmental Prediction (NCEP) and outgoing longwave radiation (OLR) data from the National Oceanic and Atmospheric Administration (NOAA),USA,we analyze the circulation pattern,precipitation distribution,convection,temperature,and humidity around the monsoon outbreaks in 2004 and 2008.Results show that the monsoon had a late onset in 2004 (May 19) but an early outbreak in 2008 (May 4).Prior to the monsoon outbreak in 2008,cross-equatorial flows in Somalia were weaker than in 2004,subtropical precipitation did not arrive in southern China as it did in 2004,and the strongest convection was located more southward than in 2004.The results also indicate that accumulated rainfall in the Indochina Peninsula was about 61% of that in 2004 during a period of 25 days leading up to the monsoon outbreak,causing differences in land surface processes and then different activity levels for the summer monsoon.Post-onset warm and humid conditions in 2008 (2004) maintained through the end of October (mid-September),while the summer monsoon lasted longer in 2008 than in 2004.展开更多
The East Asian Summer Monsoon(EASM)provides the majority of annual rainfall to countries in East Asia.Although state-of-the-art models broadly project increased EASM rainfall,the spread of projections is large and sim...The East Asian Summer Monsoon(EASM)provides the majority of annual rainfall to countries in East Asia.Although state-of-the-art models broadly project increased EASM rainfall,the spread of projections is large and simulations of present-day rainfall show significant climatological biases.Systematic evapotranspiration biases occur locally over East Asia,and globally over land,in simulations both with and without a coupled ocean.This study explores the relationship between evapotranspiration and EASM precipitation biases.First,idealized model simulations are presented in which the parameterization of land evaporation is modified,while sea surface temperature is fixed.The results suggest a feedback whereby excessive evapotranspiration over East Asia results in cooling of land,a weakened monsoon low,and a shift of rainfall from the Philippine Sea to China,further fueling evapotranspiration.Cross-model regressions against evapotranspiration over China indicate a similar pattern of behavior in Atmospheric Model Intercomparison Project(AMIP)simulations.Possible causes of this pattern are investigated.The feedback is not explained by an overly intense global hydrological cycle or by differences in radiative processes.Analysis of land-only simulations indicates that evapotranspiration biases are present even when models are forced with prescribed rainfall.These are strengthened when coupled to the atmosphere,suggesting a role for land-model errors in driving atmospheric biases.Coupled atmosphere-ocean models are shown to have similar evapotranspiration biases to those in AMIP over China,but different precipitation biases,including a northward shift in the ITCZ over the Pacific and Atlantic Oceans.展开更多
When the traditional drill and blast method is applied to rock crushing projects,it has strong vibration,loud noise and dust pollution,so it cannot be used in densely populated areas such as urban public works.We deve...When the traditional drill and blast method is applied to rock crushing projects,it has strong vibration,loud noise and dust pollution,so it cannot be used in densely populated areas such as urban public works.We developed a supercritical CO_(2)true triaxial pneumatic rock-breaking experimental system,and conducted laboratory and field tests of dry ice powder pneumatic rock-breaking.The characteristics of the blast-induced vibration velocity waveform and the evolution of the vibration velocity and frequency with the focal distance were analyzed and discussed.The fracturing mechanism of dry ice powder pneumatic rock breaking is studied.The research results show that:(1)The vibration velocity induced by dry ice powder pneumatic rock breaking decays as a power function with the increase of the focal distance;(2)The vibration frequency caused by dry ice powder pneumatic rock breaking is mainly distributed in 1–120 Hz.Due to the dispersion effect,the dominant frequency of 10–30 Hz appears abnormally attenuated;(3)The traditional CO_(2)phase change fracturing energy calculation formula is also applicable to dry ice pneumatic rock breaking technology,and the trinitrotoluene(TNT)equivalent of fracturing energy is applicable to the Sadovsky formula;(4)Dry ice powder pneumatic rock breaking is shock wave and highenergy gas acting together to fracture rock,which can be divided into three stages,among which the gas wedge action of high-energy gas plays a dominant role in rock mass damage.展开更多
The western North Pacific summer monsoon(WNPSM)is an important subcomponent of the Asian summer monsoon.The equatorial zonal wind(EZW)in the lower troposphere over the western Pacific may play a critical role in the e...The western North Pacific summer monsoon(WNPSM)is an important subcomponent of the Asian summer monsoon.The equatorial zonal wind(EZW)in the lower troposphere over the western Pacific may play a critical role in the evolution of the El Niño-Southern Oscillation(ENSO).The possible linkage between the EZW over the western Pacific and the offequatorial monsoonal winds associated with the WNPSM and its decadal changes have not yet been fully understood.Here,we find a non-stationary relationship between the WNPSM and the western Pacific EZW,significantly strengthening their correlation around the late 1980s/early 1990s.This observed shift in the WNPSM–EZW relationship could be explained by the changes in the related sea surface temperature(SST)configurations across the tropical oceans.The enhanced influence from the springtime tropical North Atlantic,summertime tropical central Pacific,and maritime continent SST anomalies may be working together in contributing to the recent intensified WNPSM–EZW co-variability.The observed recent strengthening of the WNPSM–EZW relationship may profoundly impact the climate system,including prompting more effective feedback from the WNPSM on subsequent ENSO evolution and bolstering a stronger biennial tendency of the WNPSM–ENSO coupled system.The results obtained herein imply that the WNPSM,EZW,ENSO,and the tropical North Atlantic SST may be closely linked within a unified climate system with a quasi-biennial rhythm occurring during recent decades,accompanied by a reinforcement of the WNPSM–ENSO interplay quite possibly triggered by enhanced tropical Pacific–Atlantic cross-basin interactions.These results highlight the importance of the tropical Atlantic cross-basin influences in shaping the spatial structure of WNPSM-related wind anomalies and the WNPSM–ENSO interaction.展开更多
The dynamical prediction of the Asian-Australian monsoon(AAM)has been an important and long-standing issue in climate science.In this study,the predictability of the first two leading modes of the AAM is studied using...The dynamical prediction of the Asian-Australian monsoon(AAM)has been an important and long-standing issue in climate science.In this study,the predictability of the first two leading modes of the AAM is studied using retrospective prediction datasets from the seasonal forecasting models in four operational centers worldwide.Results show that the model predictability of the leading AAM modes is sensitive to how they are defined in different seasonal sequences,especially for the second mode.The first AAM mode,from various seasonal sequences,coincides with the El Niño phase transition in the eastern-central Pacific.The second mode,initialized from boreal summer and autumn,leads El Niño by about one year but can exist during the decay phase of El Niño when initialized from boreal winter and spring.Our findings hint that ENSO,as an early signal,is conducive to better performance of model predictions in capturing the spatiotemporal variations of the leading AAM modes.Still,the persistence barrier of ENSO in spring leads to poor forecasting skills of spatial features.The multimodel ensemble(MME)mean shows some advantage in capturing the spatiotemporal variations of the AAM modes but does not provide a significant improvement in predicting its temporal features compared to the best individual models in predicting its temporal features.The BCC_CSM1.1M shows promising skill in predicting the two AAM indices associated with two leading AAM modes.The predictability demonstrated in this study is potentially useful for AAM prediction in operational and climate services.展开更多
The simulation and prediction of the climatology and interannual variability of the East Asia winter monsoon(EAWM),as well as the associated atmospheric circulation,was investigated using the hindcast data from Global...The simulation and prediction of the climatology and interannual variability of the East Asia winter monsoon(EAWM),as well as the associated atmospheric circulation,was investigated using the hindcast data from Global Seasonal Forecast System version 5(GloSea5),with a focus on the evolution of model bias among different forecast lead times.While GloSea5 reproduces the climatological means of large-scale circulation systems related to the EAWM well,systematic biases exist,including a cold bias for most of China’s mainland,especially for North and Northeast China.GloSea5 shows robust skill in predicting the EAWM intensity index two months ahead,which can be attributed to the performance in representing the leading modes of surface air temperature and associated background circulation.GloSea5 realistically reproduces the synergistic effect of El Niño–Southern Oscillation(ENSO)and the Arctic Oscillation(AO)on the EAWM,especially for the western North Pacific anticyclone(WNPAC).Compared with the North Pacific and North America,the representation of circulation anomalies over Eurasia is poor,especially for sea level pressure(SLP),which limits the prediction skill for surface air temperature over East Asia.The representation of SLP anomalies might be associated with the model performance in simulating the interaction between atmospheric circulations and underlying surface conditions.展开更多
The South China Sea Summer Monsoon(SCSSM)onset is characterized by an apparent seasonal conversion of circulation and convection.Accordingly,various indices have been introduced to identify the SCSSM onset date.Howeve...The South China Sea Summer Monsoon(SCSSM)onset is characterized by an apparent seasonal conversion of circulation and convection.Accordingly,various indices have been introduced to identify the SCSSM onset date.However,the onset dates as determined by various indices can be very inconsistent.It not only limits the determination of onset dates but also misleads the assessment of prediction skills.In 2021,the onset time as identified by the circulation criteria was 20 May,which is 12 days earlier than that deduced by also considering the convection criteria.The present study mainly ascribes such circulation-convection inconsistency to the activities of tropical cyclones(TCs)modulated by the Madden-Julian Oscillation(MJO).The convection of TC“Yaas”(2021)acted as an upper-level diabatic heat source to the north of the SCS,facilitating the circulation transition.Afterward,TC“Choi-wan”(2021)over the western Pacific aided the westerlies to persist at lower levels while simultaneously suppressing moist convection over the SCS.Accurate predictions using the ECMWF S2S forecast system were obtained only after the MJO formation.The skillful prediction of the MJO during late spring may provide an opportunity to accurately predict the establishment of the SCSSM several weeks in advance.展开更多
The long-term trend of the Arabian Sea surface temperature(ASST)during the formation of the South Asian summer monsoon(SASM)is discussed in this manuscript.From April to June,ASST changed from a meridional gradual dis...The long-term trend of the Arabian Sea surface temperature(ASST)during the formation of the South Asian summer monsoon(SASM)is discussed in this manuscript.From April to June,ASST changed from a meridional gradual distribution to a spatially uniform distribution and then to a zonal gradual distribution.The South Asian summer monsoon intensity(SASMI)and South Asian summer monsoon direction(SASMD)indicate that the variation of the ASST is highly related to the formation of the SASM during the summer monsoon period and can contribute to the spread of the SASM from the Southwest Arabian Sea throughout all of South Asia.Results of the correlation between the ASST and SASMI for the same month and its adjacent months were the same,and the areas of the positive correlation between the ASST and SASMI significantly increased from May–June as compared to April–May.The maximum correlation coefficient was 0.86.The results of the ASST and SASMD for the same month and its adjacent months were substantially different.However,the ASST and SASMD for May and April also showed a high positive correlation with a maximum correlation coefficient of 0.61 in the southwestern Arabian Sea.Existence of the ASST had a spatially consistent and significant upward trend with a mean increase of 0.6℃during the summer monsoon period from 1980 to 2020(between April and September),whereas the SASMI had a strengthening trend along the western and southwestern regions of the Arabian Sea and the southeastern region of the Arabian Peninsula.Meanwhile,the rest of the study regions showed a declining trend.Overall,the entire study region showed a slight downward trend,and the average value decreased by 0.02ms^(−1).展开更多
Organic solar cells(OSCs) especially non-fullerene OSCs(NF-OSCs) are promising to become the next-generation of commercial applications and have received great attention from many researchers due to their typical adva...Organic solar cells(OSCs) especially non-fullerene OSCs(NF-OSCs) are promising to become the next-generation of commercial applications and have received great attention from many researchers due to their typical advantages of low cost,light weight,and flexibility [1,2].展开更多
The future changes in the relationship between the South Asian summer monsoon(SASM)and the East Asian summer monsoon(EASM)are investigated by using the high-emissions Shared Socioeconomic Pathway 5-8.5(SSP5-8.5)experi...The future changes in the relationship between the South Asian summer monsoon(SASM)and the East Asian summer monsoon(EASM)are investigated by using the high-emissions Shared Socioeconomic Pathway 5-8.5(SSP5-8.5)experiments from 26 coupled models that participated in the phase 6 of the Coupled Model Intercomparison Project(CMIP6).Six models,selected based on their best performance in simulating the upper-and lower-level pathways related to the SASM-EASM teleconnection in the historical run,can capture the positive relationship between the SASM and the rainfall over northern China.In the future scenario,the upper-level teleconnection wave pattern connecting the SASM and the EASM exhibits a significant weakening trend,due to the rainfall anomalies decrease over the northern Indian Peninsula in the future.At the lower level,the western North Pacific anticyclone is projected to strengthen in the warming climate.The positive(negative)rainfall anomalies associated with positive(negative)SASM rainfall anomalies are anticipated to extend southward from northern China to the Yangtze-Huai River valley,the Korea Peninsula,and southern Japan.The connection in the lower-level pathway may be strengthened in the future.展开更多
基金supported by the National Natural Science Foundation of China[grant number 42275025]the Youth Innovation Promotion Association of the Chinese Academy of Sciences[grant number 2023084].
基金supported by the National Natural Science Foundation of China(Grant No.42275025).
文摘This study identifies break events of the South China Sea(SCS)summer monsoon(SCSSM)based on 42 years of data from 1979 to 2020,and investigates their statistical characteristics and associated atmospheric anomalies.A total of 214 break events are identified by examining the convection evolution during each monsoon season.It is found that most events occur between June and September and show a roughly even distribution.Short-lived events(3–7 days)are more frequent,accounting for about two thirds of total events,with the residual one third for long-lived events(8–24 days).The SCSSM break is featured by drastic variations in various atmospheric variables.Particularly,the convection and precipitation change from anomalous enhancement in adjoining periods to a substantial suppression during the break,with the differences being more than 60 W m−2 for outgoing longwave radiation(OLR)and 10 mm d−1 for precipitation.This convection/precipitation suppression is accompanied by an anomalous anticyclone in the lower troposphere,corresponding to a remarkable westward retreat of the monsoon trough from the Philippine Sea to the Indochina Peninsula,which reduces the transportation of water vapor into the SCS.Besides,the pseudo-equivalent potential temperature()declines sharply,mainly attributable to the local specific humidity reduction caused by downward dry advection.Furthermore,it is found that the suppressed convection and anomalous anticyclone responsible for the monsoon break form near the equatorial western Pacific and then propagate northwestward to the SCS.
基金funded by the National Natural Science Foundation of China(grants 41571054 and 31622015)the National Basic Research Program of China(grant 2014CB954100)+1 种基金Sichuan University(Fundamental Research Funds for the Central Universities,SCU2021D006 and SCU2022D003Institutional Research Funds,2021SCUNL102).
文摘Biogeographical barriers to gene flow are central to plant phylogeography.In East Asia,plant distribution is greatly influenced by two phylogeographic breaks,the Mekong-Salween Divide and Tanaka-Kaiyong Line,however,few studies have investigated how these barriers affect the genetic diversity of species that are distributed across both.Here we used 14 microsatellite loci and four chloroplast DNA fragments to examine genetic diversity and distribution patterns of 49 populations of Populus rotundifolia,a species that spans both the Mekong-Salween Divide and the Tanaka-Kaiyong Line in southwestern China.Demographic and migration hypotheses were tested using coalescent-based approaches.Limited historical gene flow was observed between the western and eastern groups of P.rotundifolia,but substantial flow occurred across both the Mekong-Salween Divide and Tanaka-Kaiyong Line,manifesting in clear admixture and high genetic diversity in the central group.Wind-borne pollen and seeds may have facilitated the dispersal of P.rotundifolia following prevalent northwest winds in the spring.We also found that the Hengduan Mountains,where multiple genetic barriers were detected,acted on the whole as a barrier between the western and eastern groups of P.rotundifolia.Ecological niche modeling suggested that P.rotundifolia has undergone range expansion since the last glacial maximum,and demographic reconstruction indicated an earlier population expansion around 600 Ka.The phylogeographic pattern of P.rotundifolia reflects the interplay of biological traits,wind patterns,barriers,niche differentiation,and Quaternary climate history.This study emphasizes the need for multiple lines of evidence in understanding the Quaternary evolution of plants in topographically complex areas.
基金supported by the Program for National Defense Science and Technology Foundation Strengtheningthe Youth Foundation of Rocket Force University of Engineering(Grant No.2021QN-B014)。
文摘A submerged cavitation water jet(SCWJ)is an effective method to recycle solid propellant from obsolete solid engines by the breaking method.Solid propellant's breaking modes and mechanical process under SCWJ impact are unclear.This study aims to understand those impact breaking mechanisms.The hydroxyl-terminated polybutadiene(HTPB)propellant was chosen as the research material,and a self-designed test system was used to conduct impact tests at four different working pressures.The high-speed camera characterized crack propagation,and the DIC method calculated strain change during the impact process.Besides,micro and macro fracture morphologies were characterized by scanning electron microscope(SEM)and computed tomography(CT)scanning.The results reveal that the compressive strain concentration region locates right below the nozzle,and the shear strain region distributes symmetrically with the jet axis,which increases to 4% at first 16th ms,the compressive strain rises to 2% and 6% in the axial and transverse direction,respectively.The two tensile cracks formed first at the compression strain concentrate region,and there generate many shear cracks around the tensile cracks,and those shear cracks that develop and aggregate cause the cracks to become wider and cut through the tensile cracks,forming the tensile-shear cracks and the impact parts eventually fail.The HTPB propellant forms a breaking hole shaped conical after impact 10 s.The mass loss increases by 17 times at maximum,with the working pressure increasing by three times.Meanwhile,the damage value of the breaking hole remaining on the surface increases by 7.8 times while 2.9 times in the depth of the breaking hole.The breaking efficiency is closely affected by working pressures.The failure modes of HTPB impacted by SCWJ are classified as tensile crack-dominated and tensile-shear crack-dominated damage mechanisms.
基金supported by the National Natural Science Foundation of China(42161007)the Scientific Research Program for Higher Education Institutions of Gansu Province(2021B-081)the Natural Science Foundation of Gansu Province(22JR5RA074).
文摘The isotope composition in precipitation has been widely considered as a tracer of monsoon activity.Compared with the coastal region,the monsoon margin usually has limited precipitation with large fluctuation and is usually sensitive to climate change.The water resource management in the monsoon margin should be better planned by understanding the composition of precipitation isotope and its influencing factors.In this study,the precipitation samples were collected at five sampling sites(Baiyin City,Kongtong District,Maqu County,Wudu District,and Yinchuan City)of the monsoon margin in the northwest of China in 2022 to analyze the characteristics of stable hydrogen(δD)and oxygen(δ18O)isotopes.We analyzed the impact of meteorological factors(temperature,precipitation,and relative humidity)on the composition of precipitation isotope at daily level by regression analysis,utilized the Hybrid Single-Particle Lagrangian Integrated Trajectory(HYSPLIT)-based backward trajectory model to simulate the air mass trajectory of precipitation events,and adopted the potential source contribution function(PSCF)and concentration weighted trajectory(CWT)to analyze the water vapor sources.The results showed that compared with the global meteoric water line(GMWL),the slope of the local meteoric water line(LMWL;δD=7.34δ^(18)O-1.16)was lower,indicating the existence of strong regional evaporation in the study area.Temperature significantly contributed toδ18O value,while relative humidity had a significant negative effect onδ18O value.Through the backward trajectory analysis,we found eight primary locations that were responsible for the water vapor sources of precipitation in the study area,of which moisture from the Indian Ocean to South China Sea(ITSC)and the western continental(CW)had the greatest influence on precipitation in the study area.The hydrogen and oxygen isotopes in precipitation are significantly influenced by the sources and transportation paths of air mass.In addition,the results of PSCF and CWT analysis showed that the water vapor source areas were primarily distributed in the south and northwest direction of the study area.
文摘The West African Monsoon (WAM) is characterized by strong decadal and multi-decadal variability and the impacts can be catastrophic for the local populations. One of the factors put forward to explain this variability involves the role of atmospheric dynamics, linked in particular to the Saharan Heat Low (SHL). This article addresses this question by comparing the sets of preindustrial control and historical simulation data from climate models carried out in the framework of the CMIP5 project and observations data over the 20<sup>th</sup> century. Through multivariate statistical analyses, it was established that decadal modes of ocean variability and decadal variability of Saharan atmospheric dynamics significantly influence decadal variability of monsoon precipitation. These results also suggest the existence of external anthropogenic forcing, which is superimposed on the decadal natural variability inducing an intensification of the signal in the historical simulations compared to preindustrial control simulations. We have also shown that decadal rainfall variability in the Sahel, once the influence of oceanic modes has been eliminated, appears to be driven mainly by the activity of the Arabian Heat Low (AHL) in the central Sahel, and by the structure of the meridional temperature gradient over the inter-tropical Atlantic in the western Sahel.
基金a donation from Trond Mohn,c/o Frank Mohn AS,for financing part of the workGrants from the Nansen Scientific Society,EU-FP7[project number 295092],INDOMARECLIM
文摘During the summer monsoon season, strong coastal upwelling occurs along the southwest coast of India and at the southern tip of India, which cools the surface temperature of the waters around these regions. The summer monsoon current carries the upwelled cold waters into the Bay of Bengal and forms the ‘cold pool of the Bay of Bengal', with its core south of Sri Lanka and over the southcentral Bay of Bengal. The present study focuses on the intrusion of these cold waters into the south of the Bay of Bengal, its interannual variability, and its association with the surface wind during the break phase of the summer monsoon, when strong westerly surface winds flow south of 10°N.The authors hypothesize that the enhanced cooling in the cold pool region during monsoon spells is associated with the strong westerly wind stress there during the break spells of the monsoon.Seven cases of long break monsoon spells that occurred during the nine years from 2001 to 2009 are analyzed, and the results confirm our hypothesis.
文摘Using a low-order spectral model derived from the equatorial equilibrium model, possible physical mechanisms are interpreted by the theory of multiple equilibria states for the active and break phases of the South Asian Monsoon, with consideration of the effects of heating by cumulus heating and cooling by radiation. The result shows that the South Asian Monsoon is active when the cumulus convection intensifies (or the radiation cooling weakens). the monsoon breaks when the convection weakens (or the cooling intensifies). It is consistent with the hypothesis of cloud-radiation by Krishnamurti et al.
基金research fellowship offered by ISRO under RESPOND program[No.ISRO/RES/2/406/16-17]。
文摘Global Positioning System(GPS)measurements of integrated water vapor(IWV)for two years(2014 and 2015)are presented in this paper.Variation of IWV during active and break spells of Indian summer monsoon has been studied for a tropical station Hyderabad(17.4°N,78.46°E).The data is validated with ECMWF Re-Analysis(ERA)91 level data.Relationships of IWV with other atmospheric variables like surface temperature,rain,and precipitation efficiency have been established through cross-correlation studies.A positive correlation coefficient is observed between IWV and surface temperature over two years.But the coefficient becomes negative when only summer monsoon months(June,July,August,and September)are considered.Rainfall during these months cools down the surface and could be the reason for this change in the correlation coefficient.Correlation studies between IWV-precipitation,IWVprecipitation efficiency(P.E),and precipitation-P.E show that coefficients are-0.05,-0.10 and 0.983 with 95%confidence level respectively,which proves that the efficacy of rain does not depend only on the level of water vapor.A proper dynamic mechanism is necessary to convert water vapor into the rain.The diurnal variations of IWV during active and break spells have been analyzed.The amplitudes of diurnal oscillation and its harmonics of individual spell do not show clear trends but the mean amplitudes of the break spells are approximately double than those of the active spells.The amplitudes of diurnal,semidiurnal and ter-diurnal components during break spells are 1.08 kg/m^(2),0.52 kg/m;and 0.34 kg/m;respectively.The corresponding amplitudes during active spells are 0.68 kg/m^(2),0.41 kg/m;and 0.23 kg/m;.
基金study was supported by the National Natural Science Foundation of China(Grant Nos.42230605 and 41721004).
文摘Studies of the multi-scale climate variability of the Asian monsoon are essential to an advanced understanding of the physical processes of the global climate system.In this paper,the progress achieved in this field is systematically reviewed,with a focus on the past several years.The achievements are summarized into the following topics:(1)the onset of the South China Sea summer monsoon;(2)the East Asian summer monsoon;(3)the East Asian winter monsoon;and(4)the Indian summer monsoon.Specifically,new results are highlighted,including the advanced or delayed local monsoon onset tending to be synchronized over the Arabian Sea,Bay of Bengal,Indochina Peninsula,and South China Sea;the basic features of the record-breaking mei-yu in 2020,which have been extensively investigated with an emphasis on the role of multi-scale processes;the recovery of the East Asian winter monsoon intensity after the early 2000s in the presence of continuing greenhouse gas emissions,which is believed to have been dominated by internal climate variability(mostly the Arctic Oscillation);and the accelerated warming over South Asia,which exceeded the tropical Indian Ocean warming,is considered to be the main driver of the Indian summer monsoon rainfall recovery since 1999.A brief summary is provided in the final section along with some further discussion on future research directions regarding our understanding of the Asian monsoon variability.
基金Foundation project of Guangdong Ocean University(0812070)
文摘The South China Sea summer monsoon is an important system affecting the weather and climate in China;its outbreak and evolution vary from year to year.Using the reanalysis data from the U.S.National Centers for Environmental Prediction (NCEP) and outgoing longwave radiation (OLR) data from the National Oceanic and Atmospheric Administration (NOAA),USA,we analyze the circulation pattern,precipitation distribution,convection,temperature,and humidity around the monsoon outbreaks in 2004 and 2008.Results show that the monsoon had a late onset in 2004 (May 19) but an early outbreak in 2008 (May 4).Prior to the monsoon outbreak in 2008,cross-equatorial flows in Somalia were weaker than in 2004,subtropical precipitation did not arrive in southern China as it did in 2004,and the strongest convection was located more southward than in 2004.The results also indicate that accumulated rainfall in the Indochina Peninsula was about 61% of that in 2004 during a period of 25 days leading up to the monsoon outbreak,causing differences in land surface processes and then different activity levels for the summer monsoon.Post-onset warm and humid conditions in 2008 (2004) maintained through the end of October (mid-September),while the summer monsoon lasted longer in 2008 than in 2004.
基金supported by the UK–China Research and Innovation Partnership Fund, through the Met Office Climate Science for Service Partnership (CSSP) China, as part of the Newton Fund
文摘The East Asian Summer Monsoon(EASM)provides the majority of annual rainfall to countries in East Asia.Although state-of-the-art models broadly project increased EASM rainfall,the spread of projections is large and simulations of present-day rainfall show significant climatological biases.Systematic evapotranspiration biases occur locally over East Asia,and globally over land,in simulations both with and without a coupled ocean.This study explores the relationship between evapotranspiration and EASM precipitation biases.First,idealized model simulations are presented in which the parameterization of land evaporation is modified,while sea surface temperature is fixed.The results suggest a feedback whereby excessive evapotranspiration over East Asia results in cooling of land,a weakened monsoon low,and a shift of rainfall from the Philippine Sea to China,further fueling evapotranspiration.Cross-model regressions against evapotranspiration over China indicate a similar pattern of behavior in Atmospheric Model Intercomparison Project(AMIP)simulations.Possible causes of this pattern are investigated.The feedback is not explained by an overly intense global hydrological cycle or by differences in radiative processes.Analysis of land-only simulations indicates that evapotranspiration biases are present even when models are forced with prescribed rainfall.These are strengthened when coupled to the atmosphere,suggesting a role for land-model errors in driving atmospheric biases.Coupled atmosphere-ocean models are shown to have similar evapotranspiration biases to those in AMIP over China,but different precipitation biases,including a northward shift in the ITCZ over the Pacific and Atlantic Oceans.
基金supported by the State Key Laboratory Open Fund(No.HKLBEF202004)the Natural Science Foundation of Jiangsu Province(No.BK20201313)+2 种基金the Key Program of National Natural Science Foundation of China(No.51934007)the Major Scientific and Technological Innovation Program in Shandong Province(No.2019JZZY020505)the National Key Research and Development Program of China(No.2022YFC3004700)。
文摘When the traditional drill and blast method is applied to rock crushing projects,it has strong vibration,loud noise and dust pollution,so it cannot be used in densely populated areas such as urban public works.We developed a supercritical CO_(2)true triaxial pneumatic rock-breaking experimental system,and conducted laboratory and field tests of dry ice powder pneumatic rock-breaking.The characteristics of the blast-induced vibration velocity waveform and the evolution of the vibration velocity and frequency with the focal distance were analyzed and discussed.The fracturing mechanism of dry ice powder pneumatic rock breaking is studied.The research results show that:(1)The vibration velocity induced by dry ice powder pneumatic rock breaking decays as a power function with the increase of the focal distance;(2)The vibration frequency caused by dry ice powder pneumatic rock breaking is mainly distributed in 1–120 Hz.Due to the dispersion effect,the dominant frequency of 10–30 Hz appears abnormally attenuated;(3)The traditional CO_(2)phase change fracturing energy calculation formula is also applicable to dry ice pneumatic rock breaking technology,and the trinitrotoluene(TNT)equivalent of fracturing energy is applicable to the Sadovsky formula;(4)Dry ice powder pneumatic rock breaking is shock wave and highenergy gas acting together to fracture rock,which can be divided into three stages,among which the gas wedge action of high-energy gas plays a dominant role in rock mass damage.
基金This work was supported by the National Natural Science Foundation of China(Grant No:41776031)the National Key Research and Development Program of China(Grant 2018YFC1506903)+1 种基金the team project funding of scientific research innovation for universities in Guangdong province(Grant 2019KCXTF021)the program for scientific research start-up funds of Guangdong Ocean University(Grant R17051).
文摘The western North Pacific summer monsoon(WNPSM)is an important subcomponent of the Asian summer monsoon.The equatorial zonal wind(EZW)in the lower troposphere over the western Pacific may play a critical role in the evolution of the El Niño-Southern Oscillation(ENSO).The possible linkage between the EZW over the western Pacific and the offequatorial monsoonal winds associated with the WNPSM and its decadal changes have not yet been fully understood.Here,we find a non-stationary relationship between the WNPSM and the western Pacific EZW,significantly strengthening their correlation around the late 1980s/early 1990s.This observed shift in the WNPSM–EZW relationship could be explained by the changes in the related sea surface temperature(SST)configurations across the tropical oceans.The enhanced influence from the springtime tropical North Atlantic,summertime tropical central Pacific,and maritime continent SST anomalies may be working together in contributing to the recent intensified WNPSM–EZW co-variability.The observed recent strengthening of the WNPSM–EZW relationship may profoundly impact the climate system,including prompting more effective feedback from the WNPSM on subsequent ENSO evolution and bolstering a stronger biennial tendency of the WNPSM–ENSO coupled system.The results obtained herein imply that the WNPSM,EZW,ENSO,and the tropical North Atlantic SST may be closely linked within a unified climate system with a quasi-biennial rhythm occurring during recent decades,accompanied by a reinforcement of the WNPSM–ENSO interplay quite possibly triggered by enhanced tropical Pacific–Atlantic cross-basin interactions.These results highlight the importance of the tropical Atlantic cross-basin influences in shaping the spatial structure of WNPSM-related wind anomalies and the WNPSM–ENSO interaction.
基金supported by the National Natural Science Foundation of China(Grant Nos.U2242206,41975094 and 41905062)the National Key Research and Development Program on monitoring,Early Warning and Prevention of Major Natural Disaster(Grant Nos.2017YFC1502302 and 2018YFC1506005)+1 种基金the Basic Research and Operational Special Project of CAMS(Grant No.2021Z007)the Met Office Climate Science for Service Partnership(CSSP)China.
文摘The dynamical prediction of the Asian-Australian monsoon(AAM)has been an important and long-standing issue in climate science.In this study,the predictability of the first two leading modes of the AAM is studied using retrospective prediction datasets from the seasonal forecasting models in four operational centers worldwide.Results show that the model predictability of the leading AAM modes is sensitive to how they are defined in different seasonal sequences,especially for the second mode.The first AAM mode,from various seasonal sequences,coincides with the El Niño phase transition in the eastern-central Pacific.The second mode,initialized from boreal summer and autumn,leads El Niño by about one year but can exist during the decay phase of El Niño when initialized from boreal winter and spring.Our findings hint that ENSO,as an early signal,is conducive to better performance of model predictions in capturing the spatiotemporal variations of the leading AAM modes.Still,the persistence barrier of ENSO in spring leads to poor forecasting skills of spatial features.The multimodel ensemble(MME)mean shows some advantage in capturing the spatiotemporal variations of the AAM modes but does not provide a significant improvement in predicting its temporal features compared to the best individual models in predicting its temporal features.The BCC_CSM1.1M shows promising skill in predicting the two AAM indices associated with two leading AAM modes.The predictability demonstrated in this study is potentially useful for AAM prediction in operational and climate services.
基金supported by the State Key Program of the National Natural Science of China(Grant No.41730964)the National Key Research and Development Program on Monitoring,Early Warning and Prevention of Major Natural Disaster(2018YFC1506000)+2 种基金the National Natural Science Foundation of China(Grant Nos.41975091 and 42175047)National Basic Research Program of China(2015CB453203)UK-China Research&Innovation Partnership Fund through the Met Office Climate Science for Service Partnership(CSSP)China as part of the Newton Fund.
文摘The simulation and prediction of the climatology and interannual variability of the East Asia winter monsoon(EAWM),as well as the associated atmospheric circulation,was investigated using the hindcast data from Global Seasonal Forecast System version 5(GloSea5),with a focus on the evolution of model bias among different forecast lead times.While GloSea5 reproduces the climatological means of large-scale circulation systems related to the EAWM well,systematic biases exist,including a cold bias for most of China’s mainland,especially for North and Northeast China.GloSea5 shows robust skill in predicting the EAWM intensity index two months ahead,which can be attributed to the performance in representing the leading modes of surface air temperature and associated background circulation.GloSea5 realistically reproduces the synergistic effect of El Niño–Southern Oscillation(ENSO)and the Arctic Oscillation(AO)on the EAWM,especially for the western North Pacific anticyclone(WNPAC).Compared with the North Pacific and North America,the representation of circulation anomalies over Eurasia is poor,especially for sea level pressure(SLP),which limits the prediction skill for surface air temperature over East Asia.The representation of SLP anomalies might be associated with the model performance in simulating the interaction between atmospheric circulations and underlying surface conditions.
基金jointly supported by the National Natural Science Foundation of China (Grant Nos. 42005011, 41830969)the Basic Scientific Research and Operation Foundation of CAMS (Grant Nos. 2021Z004)supported by the Jiangsu Collaborative Innovation Center for Climate Change
文摘The South China Sea Summer Monsoon(SCSSM)onset is characterized by an apparent seasonal conversion of circulation and convection.Accordingly,various indices have been introduced to identify the SCSSM onset date.However,the onset dates as determined by various indices can be very inconsistent.It not only limits the determination of onset dates but also misleads the assessment of prediction skills.In 2021,the onset time as identified by the circulation criteria was 20 May,which is 12 days earlier than that deduced by also considering the convection criteria.The present study mainly ascribes such circulation-convection inconsistency to the activities of tropical cyclones(TCs)modulated by the Madden-Julian Oscillation(MJO).The convection of TC“Yaas”(2021)acted as an upper-level diabatic heat source to the north of the SCS,facilitating the circulation transition.Afterward,TC“Choi-wan”(2021)over the western Pacific aided the westerlies to persist at lower levels while simultaneously suppressing moist convection over the SCS.Accurate predictions using the ECMWF S2S forecast system were obtained only after the MJO formation.The skillful prediction of the MJO during late spring may provide an opportunity to accurately predict the establishment of the SCSSM several weeks in advance.
基金supported by the Global Change and Airsea Interaction Project,the Research and Development of Marine Electromagnetic Field Sensors and Demonstration of Electromagnetic Detection Applications(No.2022YFC 3104000)the Special Project.
文摘The long-term trend of the Arabian Sea surface temperature(ASST)during the formation of the South Asian summer monsoon(SASM)is discussed in this manuscript.From April to June,ASST changed from a meridional gradual distribution to a spatially uniform distribution and then to a zonal gradual distribution.The South Asian summer monsoon intensity(SASMI)and South Asian summer monsoon direction(SASMD)indicate that the variation of the ASST is highly related to the formation of the SASM during the summer monsoon period and can contribute to the spread of the SASM from the Southwest Arabian Sea throughout all of South Asia.Results of the correlation between the ASST and SASMI for the same month and its adjacent months were the same,and the areas of the positive correlation between the ASST and SASMI significantly increased from May–June as compared to April–May.The maximum correlation coefficient was 0.86.The results of the ASST and SASMD for the same month and its adjacent months were substantially different.However,the ASST and SASMD for May and April also showed a high positive correlation with a maximum correlation coefficient of 0.61 in the southwestern Arabian Sea.Existence of the ASST had a spatially consistent and significant upward trend with a mean increase of 0.6℃during the summer monsoon period from 1980 to 2020(between April and September),whereas the SASMI had a strengthening trend along the western and southwestern regions of the Arabian Sea and the southeastern region of the Arabian Peninsula.Meanwhile,the rest of the study regions showed a declining trend.Overall,the entire study region showed a slight downward trend,and the average value decreased by 0.02ms^(−1).
基金the Natural Science Foundation of China (52172048, 52103221, 51873172, 22205130, 12175298)the Shandon Provincial Natural Science Foundation of China (ZR2021QB024, ZR2021QB179, ZR2021ZD06)+2 种基金the Guangdong Natural Science Foundation of China (2023A1515012323, 2023A1515010943, 2022A1515110643)the National Key Research and Development Program of China (2022YFB4200400) funded by MOST of Chinathe Fundamental Research Funds of Shandong University from China。
文摘Organic solar cells(OSCs) especially non-fullerene OSCs(NF-OSCs) are promising to become the next-generation of commercial applications and have received great attention from many researchers due to their typical advantages of low cost,light weight,and flexibility [1,2].
基金Guangdong Major Project of Basic and Applied Basic Research Foundation(2020B0301030004)National Natural Science Foundation of China(41975074)+2 种基金Guangdong Basic and Applied Basic Research Foundation(2023A1515010908)Guangdong Province Key Laboratory for Climate Change and Natural Disaster Studies(2020B1212060025)Innovation Group Project of Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai)(311021001)。
文摘The future changes in the relationship between the South Asian summer monsoon(SASM)and the East Asian summer monsoon(EASM)are investigated by using the high-emissions Shared Socioeconomic Pathway 5-8.5(SSP5-8.5)experiments from 26 coupled models that participated in the phase 6 of the Coupled Model Intercomparison Project(CMIP6).Six models,selected based on their best performance in simulating the upper-and lower-level pathways related to the SASM-EASM teleconnection in the historical run,can capture the positive relationship between the SASM and the rainfall over northern China.In the future scenario,the upper-level teleconnection wave pattern connecting the SASM and the EASM exhibits a significant weakening trend,due to the rainfall anomalies decrease over the northern Indian Peninsula in the future.At the lower level,the western North Pacific anticyclone is projected to strengthen in the warming climate.The positive(negative)rainfall anomalies associated with positive(negative)SASM rainfall anomalies are anticipated to extend southward from northern China to the Yangtze-Huai River valley,the Korea Peninsula,and southern Japan.The connection in the lower-level pathway may be strengthened in the future.
