检索结果-南通市图书馆

Relative Roles of Intraseasonal and Above-seasonal Components in the South China Sea Summer monsoon Onset

在线全文

学校读者我要写书评

暂无评论

Journal of Tropical Meteorology 2022年第2期28卷 183-193页

作者：陈佩珊简茂球高斯 school of atmospheric sciences Center for Monsoon and Environment Research and Guangdong Province Key Laboratory for Climate Change and Natural Disaster StudiesSun Yat-sen University/Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai)ZhuhaiGuangdong 519082 China

Multi-scale contributions are involved in the South China Sea(SCS)summer monsoon(SCSSM)onset process.The relative roles of intraseasonal oscillation and above-seasonal component in the year-to-year variation of the SCSSM onset are evaluated in this study.The 30-90-day and above-90-day components are major contributors to the year-to-year variation of the SCSSM onset,and the former contributes greater portion,while the 8-30-day component has little contribution to the onset.In the early onset cases,the 30-90-day westerly winds move and extend eastward from the tropical Indian Ocean(TIO)to the SCS monsoon region relatively earlier,and replace the easterly winds over the SCS with the cooperation of the 30-90-day cyclone moving southward from northern East Asia.The westerly anomalies of the above-90-day component in spring jointly contribute to the early SCSSM onset.In the late onset cases,the late eastward expansion of 30-90-day westerly wind over the TIO,accompanied by the late occurrence and weakening of the 30-90-day anticyclone over the SCS,and its late withdraw from the SCS,as well as the persistent easterly anomalies of above-90-day component,suppress the SCSSM onset.However,the SCSSM outbreaks in the obvious weakening stage of 30-90-day easterly anomalies.The easterlies-to-westerlies transition of the 30-90-day 850-hPa zonal wind over the SCS in spring is closely associated with sea surface temperature in the tropical western Pacific in preceding winter and spring,while the interannual variation of the above-90-day zonal wind in April-May is closely related to the decaying stage of the El Niño-Southern Oscillation events.

关键词： South China Sea summer monsoon onset intraseasonal oscillation above-seasonal component relative roles

INTERDECADAL VARIABILITY OF QUASI-BIENNIAL OSCILLATION OF STRATOSPHERIC ZONAL WIND

在线全文

学校读者我要写书评

暂无评论

Journal of Tropical Meteorology 2019年第2期25卷 162-170页

作者：韩浦城简茂球林晓霞 school of atmospheric sciences/center for monsoon and environment research/guangdong province key laboratory for climate change and natural disaster studies Sun Yat-sen University guangdong Meteorological Observatory guangdong Meteorological Observation Data center

This study investigates the interdecadal variability of Quasi-biennial Oscillation(QBO) based on the sounding data in the stratosphere, ERA-40 and ERA-interim reanalysis data in the past 62 years. The QBO periodicity experiences a significant interdecadal variability; the longer(shorter) the mean period, the smaller(larger) the amplitude of variation is. The QBO amplitude varies in a cycle around 10 to 15 years and in an out-of-phase correlation with the period. In addition, there is an increasing trend of the QBO amplitude in 30 to 10 hPa, while a little declining trend in70 to 40 hPa. The deviation of the QBO zonal wind extremum centers from the equator also shows interdecadal variability. The deviation location of the easterly core is generally in the reverse side to the westerly core, which means that when the easterly core is on one side of a hemisphere, the westerly core is on the other side.

关键词： statistical feature QBO interdecadal variability zonal wind asymmetric feature

INTERANNUAL VARIABILITY OF WINTER-TO-SPRING CIRCULATION TRANSITION OVER SOUTHERN CHINA AND ITS SURROUNDING AREAS AND MECHANISMS

在线全文

学校读者我要写书评

暂无评论

Journal of Tropical Meteorology 2019年第4期25卷 471-482页

作者：周明森简茂球 Center for Monsoon and Environment Research/Guangdong Province Key Laboratory for Climate Change and Natural Disaster Studies/School of Atmospheric Sciences Sun Yat-sen UniversityGuangzhou 510275 China Southern Marine Science and Engineering guangdong laboratory(Zhuhai) Zhuhai 519082China

The climatological features and interannual variation of winter-to-spring transition over southern China and its surrounding areas, and its possible mechanisms are examined in this study. The climatological mean winter-to-spring transition is approximately in mid-March over southern China and the northern South China Sea. During the transition stage, anomalous southwest winds prevail at low-level over southern China and its nearby regions with enhanced convergence center over southern China, bringing more moisture from the Bay of Bengal(BOB) and the South China Sea(SCS) to southern China;meanwhile, the upper level is characterized by an obvious divergence wind pattern over southern China to the southwest part of Japan and enhanced upward motion. All the change of circulation is favorable to an increase of precipitation over southern China after seasonal transition. The winter-to-spring transition is predominantly on the interannual variation over southern China and the northern SCS. Early winter-to-spring transitions may induce more precipitation over southern China in spring, especially in March, while late cases will result in less precipitation. The interannual variability of the winter-to-spring transition and the related large-scale circulation are closely associated with the decaying phase of ENSO events. The warm ENSO events contribute to early winter-to-spring transitions and more precipitation over southern China.

关键词： winter-to-spring transition southern China and its surrounding areas interannual variability mechanism ENSO

atmospheric HONO formation during and after the Spring Festival holidays in a coastal city of China

在线全文

学校读者我要写书评

暂无评论

Journal of environmental sciences 2023年第5期127卷 251-263页

作者： Xue Ni Cuizhi Sun Yongyun Zhang Baoling Liang Shengzhen Zhou guangdong Lan Jun Zhao school of atmospheric sciences Guangdong Province Key Laboratory for Climate Change and Natural Disaster Studiesand Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai)Sun Yat-sen UniversityZhuhai 519082China guangdong Provincial Observation and research Station for climate environment and Air Quality change in the Pearl River Estuary Zhuhai 519082China key laboratory of Tropical Atmosphere-Ocean System Ministry of EducationZhuhai 519082China

Nitrous acid(HONO)is an important source of hydrogen oxides(HOx),which affects air quality,the atmospheric oxidation capacity,and human health.Here,we present ambient measurements of the HONO concentrations in Zhuhai,a coastal city in Southern China,from February 7 to March 15,2021.The campaign was classified into two periods during(P1)and after(P2)the Spring Festival holidays.The average HONO mixing ratio during P2(1.19±0.85 ppbv)was much higher than that during P1(0.24±0.18 ppbv),likely due to the contribution of homogeneous HONO formation.During nighttime,the heterogeneous conversion rate during P2(0.0089/hr)was considerably higher than that during P1(0.0057/hr),suggesting a higher heterogeneous NO_(2) conversion potential.However,the heterogeneous NO_(2) conversion was the dominant way during P1 with a high percentage of 88%,while comparable ratios of heterogeneous and homogeneous formation were found(54%vs.46%)during P2,indicating that the homogeneous formation was also important during P2.During daytime,homogeneous reaction was the major known pathway,with a contribution of 16%during P1 and 27%during P2,leaving large unknown HONO sources which reasonably correlated with the photo-enhanced NO_(2) conversion.Two case scenarios were additionally explored,showing that there might be a primary emission source during one scenario(February 17-18)and vehicle emissions might be the major unknown HONO source for another scenario(March 3–5).The results suggest that large unknown daytime sources still exist which need more future ambient and laboratory studies.

关键词： Nitrous acid Nocturnal and daytime budget Heterogeneous conversion Homogeneous formation Coastal area

Relationships between Springtime Sea Surface Temperatures in Different Indian Ocean Domains and Various Asian monsoons from Late Spring to the Following Summer

在线全文

学校读者我要写书评

暂无评论

Journal of Meteorological research 2023年第3期37卷 307-323页

作者： Kangtai CHEN Song YANG school of atmospheric sciences Sun Yat-sen UniversitySouthern Marine Science and Engineering Guangdong Laboratory(Zhuhai)Zhuhai 519082 guangdong province key laboratory for climate change and natural disaster studies Sun Yat-sen UniversityZhuhai 519082

We investigate the relative importance of spring sea surface temperatures(SSTs)in different Indian Ocean(IO)domains,especially the northern and southern IO,for the development and intensity of the Asian summer monsoon.By performing unsupervised neural network analysis,the self-organizing map,we extract distinct patterns of springtime IO SST.The results show that the uniform warming(cooling)of the southern IO plays a crucial role in the warming(cooling)of both the basin-wide IO and tropical IO.The southern IO thus well represents the associations of basinwide IO and tropical IO with the Asian summer monsoon,and is instrumental in the relationship between the IO and summer monsoon.A warming in the southern IO is closely related to the weakening of large-scale meridional monsoon circulation in May and summer(June–August),including suppression of the South Asian monsoon development in May and the East Asian monsoon in summer.On the other hand,a warming in the northern IO appears to be associated with an earlier South Asian monsoon onset and a stronger East Asian monsoon.In summer,the connection of the springtime IO SST with the South Asian monsoon weakens,but that with the East Asian monsoon strengthens.Finally,a robust negative correlation is found between the warming of various IO domains and the development and intensity of the Southeast Asian monsoon.

关键词： self-organizing map Indian Ocean sea surface temperature development and intensity of the Asian summer monsoon

Seasonal variation of transport pathways and potential source areas at high inorganic nitrogen wet deposition sites in southern China

在线全文

学校读者我要写书评

暂无评论

Journal of environmental sciences 2022年第4期34卷 444-453页

作者： Shuidi He Minjuan Huang Lianming Zheng Ming Chang Weihua Chen Qianqian Xie Xuemei Wang guangdong-Hongkong-Macao Joint laboratory of Collaborative Innovation for environmental Quality Institute for Environmental and Climate ResearchJinan UniversityGuangzhou 510632China school of atmospheric sciences Guangdong Province Key Laboratory for Climate Change and Natural Disaster StudiesSun Yat-sen UniversityZhuhai 519082China Southern Marine Science and Engineering guangdong laboratory Zhuhai 519082China

This study attempts to identify the dominant transport pathways,potential source areas,and their seasonal variation at sites with high inorganic nitrogen(IN)wet deposition flux in southern China.This is a long-term study(2010-2017)based on continuous deposition measurements at the Guangzhou urban site(GZ)and the Dinghushan natural Reserve site(DHS)located in the Pearl River Delta(PRD)region.A dataset on monthly IN concentration in precipitation and wet deposition flux were provided.The average annual fluxes measured at both sites(GZ:33.04±9.52,DHS:20.52±10.22 kg N/(ha·year))were higher,while the ratios of reduced to oxidized N(GZ:1.19±0.77,DHS:1.25±0.84)were lower compared with the national mean level and the previous reported level throughout the PRD region.The dominant pathways were not always consistent with the highest proportional trajectory clusters.The transport pathways contributing most of deposition were identified in the north and northnortheast in the dry season and in the east-southeast,east,and south-southwest in the wet season.A weighted potential source contribution function(WPSCF)value>0.3 was determined reasonably to define the potential source area.Emission within the PRD region contributed the majority(≥95%at both sites)of the IN deposition in the wet season,while the contribution outside the region increased significantly in the dry season(GZ:27.86%,DHS:95.26%).Our results could help create more effective policy to control precursor emissions for IN fluxes,enabling reduction of the ecological risks due to excessive nitrogen.

关键词： Inorganic nitrogen(IN) Wet deposition Seasonal variation Transport pathways Potential source areas Emission sectors

1990年代初东北8月极端高温频次的年代际减少

在线全文

学校读者我要写书评

暂无评论

atmospheric and Oceanic Science Letters 2021年第1期14卷 1-6页

作者： Wenjun Liu Ruidan Chen Zhiping Wen center for monsoon and environment research Guangdong Province Key Laboratory for Climate Change and Natural Disaster StudiesSchool of Atmospheric SciencesSun Yat-sen UniversityGuangzhouChina Department of atmospheric and Oceanic sciences Institute of Atmospheric SciencesFudan UniversityShanghaiChina Southern Marine Science and Engineering guangdong laboratory(Zhuhai) China Jiangsu Collaborative Innovation center for climate change NanjingChina

东北夏季极端高温频次在1990年代中期出现年代际增多.本文指出该年代际增多只出现在6-7月,而8月则呈现特殊性,即在1990年代初出现年代际减少.进一步分析表明,东北8月极端高温频次的年代际减少由日最高温度变率的年代际减小造成.东北日... 详细信息

东北夏季极端高温频次在1990年代中期出现年代际增多.本文指出该年代际增多只出现在6-7月,而8月则呈现特殊性,即在1990年代初出现年代际减少.进一步分析表明,东北8月极端高温频次的年代际减少由日最高温度变率的年代际减小造成.东北日最高温度受到欧亚遥相关,丝绸之路遥相关和东亚-太平洋遥相关的共同调制.1990年代初之后,西风急流上的经向风变率显著减小,丝绸之路遥相关对下游的影响减弱,导致东北日最高温度变率减小.同时,西北太平洋热带对流的变率也在1990年代初出现年代际减小,通过东亚-太平洋遥相关使东北日最高温度变率进一步减小.

关键词：东北极端高温年代际变化变率

Sub-seasonal Prediction of the South China Sea Summer monsoon Onset in the NCEP climate Forecast System Version 2

在线全文

学校读者我要写书评

暂无评论

Advances in atmospheric sciences 2022年第11期39卷 1969-1981页

作者： Weiwei WANG Song YANG Tuantuan ZHANG Qingquan LI Wei WEI school of atmospheric sciences and guangdong province key laboratory for climate change and natural disaster studies Sun Yat-sen UniversityZhuhai 519082China Southern Marine Science and Engineering guangdong laboratory(Zhuhai) Zhuhai 519082China National climate center China Meteorological AdministrationBeijing 100081China

This study depicts the sub-seasonal prediction of the South China Sea summer monsoon onset(SCSSMO)and investigates the associated oceanic and atmospheric processes,utilizing the hindcasts of the National centers for environmental Prediction(NCEP)climate Forecast System version 2(CFSv2).Typically,the SCSSMO is accompanied by an eastward retreat of the western North Pacific subtropical high(WNPSH),development of the cross-equatorial flow,and an increase in the east-west sea surface temperature(SST)gradient.These features are favorable for the onset of westerlies and strengthening of convection and precipitation over the South China Sea(SCS).A more vigorous SCSSMO process shows a higher predictability,and vice versa.The NCEP CFSv2 can successfully predict the onset date and evolution of the monsoon about 4 pentads(20 days)in advance(within 1–2 pentads)for more forceful(less vigorous)SCSSMO processes.On the other hand,the climatological SCSSMO that occurs around the 27th pentad can be accurately predicted in one pentad,and the predicted SCSSMO occurs 1–2 pentads earlier than the observed with a weaker intensity at longer leadtimes.Warm SST biases appear over the western equatorial Pacific preceding the SCSSMO.These biases induce a weaker-thanobserved WNPSH as a Gill-type response,leading to weakened low-level easterlies over the SCS and hence an earlier and less vigorous SCSSMO.In addition,after the SCSSMO,remarkable warm biases over the eastern Indian Ocean and the SCS and cold biases over the WNP induce weaker-than-observed westerlies over the SCS,thus also contributing to the less vigorous SCSSMO.

关键词： South China Sea summer monsoon onset sub-seasonal prediction the NCEP CFSv2

Causes of the Extreme Hot Midsummer in Central and South China during 2017:Role of the Western Tropical Pacific Warming

在线全文

学校读者我要写书评

暂无评论

Advances in atmospheric sciences 2019年第5期36卷 465-478页

作者： Ruidan CHEN Zhiping WEN Riyu LU Chunzai WANG Center for Monsoon and Environment Research/Guangdong Province Key Laboratory for Climate Change and Natural Disaster Studies/School of Atmospheric Sciences Sun Yat-sen University Jiangsu Collaborative Innovation center for climate change Department of atmospheric and Oceanic sciences/Institute of atmospheric sciences Fudan University State key laboratory of Numerical Modeling for atmospheric sciences and Geophysical Fluid Dynamics Institute of Atmospheric Physics Chinese Academy of Sciences University of the Chinese Academy of sciences State key laboratory of Tropical Oceanography South China Sea Institute of Oceanology Chinese Academy of Sciences

This study investigates why an extreme hot midsummer occurred in Central and South China(CSC) during 2017. It is shown that the western North Pacific subtropical high(WNPSH) was abnormally intensified and westward-extending,resulting in anomalous high pressure and consequent extreme heat over CSC. The abnormal WNPSH was favored by the warming of the western tropical Pacific(WTP), which was unrelated to ENSO and manifested its own individual effect.The WTP warming enhanced the convection in-situ and led to anomalous high pressure over CSC via a local meridional circulation. The influence of the WTP was confirmed by CAM4 model experiments. A comparison between the 2017 midsummer and 2010 midsummer(with a stronger WNPSH but weaker extreme heat) indicated that the influence of the WNPSH on extreme heat can be modulated by the associated precipitation in the northwestern flank.The role of the WTP was verified by regression analyses on the interannual variation of the WTP sea surface temperature anomaly(SSTA). On the other hand, the WTP has undergone prominent warming during the past few decades, resulting from decadal to long-term changes and favoring extreme warm conditions. Through a mechanism similar to the interannual variation, the decadal to long-term changes have reinforced the influence of WTP warming on the temperature over CSC,contributing to the more frequent hot midsummers recently. It is estimated that more than 50% of the temperature anomaly over CSC in the 2017 midsummer was due to the WTP warming, and 40% was related to the decadal to long-term changes of the WTP SSTA.

关键词： hot midsummer Central and South China western tropical Pacific decadal to long-term changes