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Recent Progress in Studies of the Variabilities and Mechanisms of the East Asian Monsoon in a Changing Climate 预览
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作者 Wen CHEN Lin WANG +4 位作者 Juan FENG Zhiping WEN Tiaojiao MA Xiuqun YANG Chenghai WANG 《大气科学进展:英文版》 SCIE CAS CSCD 2019年第9期887-901,共15页
Located in a monsoon domain,East Asia suffers devastating natural hazards induced by anomalous monsoon behaviors.East Asian monsoon(EAM)research has traditionally been a high priority for the Chinese climate community... Located in a monsoon domain,East Asia suffers devastating natural hazards induced by anomalous monsoon behaviors.East Asian monsoon(EAM)research has traditionally been a high priority for the Chinese climate community and is particularly challenging in a changing climate where the global mean temperature has been rising.Recent advances in studies of the variabilities and mechanisms of the EAM are reviewed in this paper,focusing on the interannual to interdecadal time scales.Some new results have been achieved in understanding the behaviors of the EAM,such as the evolution of the East Asian summer monsoon(EASM),including both its onset and withdrawal over the South China Sea,the changes in the northern boundary activity of the EASM,or the transitional climate zone in East Asia,and the cycle of the EASM and the East Asian winter monsoon and their linkages.In addition,understanding of the mechanism of the EAM variability has improved in several aspects,including the impacts of different types of ENSO on the EAM,the impacts from the Indian Ocean and Atlantic Ocean,and the roles of mid-to high-latitude processes.Finally,some scientific issues regarding our understanding of the EAM are proposed for future investigation. 展开更多
关键词 EAST ASIAN summer MONSOON EAST ASIAN winter MONSOON CHANGING CLIMATE MONSOON onset and withdrawal transitional CLIMATE zone different types of ENSO
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Exploring thermocline and water masses variability in southern South China Sea from the World Ocean Database (WOD) 预览
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作者 Afifi Johari Mohd Fadzil Akhir 《海洋学报:英文版》 SCIE CAS CSCD 2019年第1期38-47,共10页
Study about water characteristics (temperature and salinity) from the World Ocean Database (WOD) was conducted in the area of southern South China Sea (SSCS), covering the area of 0°–10°N, 100°–117... Study about water characteristics (temperature and salinity) from the World Ocean Database (WOD) was conducted in the area of southern South China Sea (SSCS), covering the area of 0°–10°N, 100°–117°E. From interannual analysis, upper layer (10 m) and deep water temperature (50 m) increased from 1951 until 2014. Monthly averaged show that May recorded the highest upper layer temperature while January recorded the lowest. It was different for the deep water which recorded the highest value in September and lowest in February. Contour plot for upper layer temperature in the study area shows presence of thermal front of cold water at southern part of Vietnam tip especially during peak northeast season (December–January). The appearances of warm water were obviously seen during generating southwest monsoon (May–June). Thermocline study revealed the deepest isothermal layer depth (ILD) during peak northeast and southwest monsoon. Temperature threshold at shallow area reach more than 0.8℃ during the transitional period. Water mass study described T-S profile based on particular region. Water mass during the southwest monsoon is typically well mixed compared to other seasons while strong separation according to location is very clear. During transitional period between northeast monsoon to southwest monsoon, the increasing of water temperature can be seen at Continental Shelf Water (CSW) which tend to be higher than 29℃ and vice versa condition during transitional period between southwest monsoon to northeast monsoon. Dispersion of T-S profile can be seen during southwest monsoon inside Tropical Surface Water (TSW) where the salinity and temperature become higher than during northeast monsoon. 展开更多
关键词 SOUTHERN South China Sea upper layer temperature NORTHEAST MONSOON SOUTHWEST MONSOON THERMOCLINE water mass
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Microphysical Characteristics of Precipitation during Pre-monsoon, Monsoon, and Post-monsoon Periods over the South China Sea 预览
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作者 Qingwei ZENG Yun ZHANG +5 位作者 Hengchi LEI Yanqiong XIE Taichang GAO Lifeng ZHANG Chunming WANG Yanbin HUANG 《大气科学进展:英文版》 SCIE CAS CSCD 2019年第10期1103-1120,共18页
Raindrop size distribution (RSD) characteristics over the South China Sea (SCS) are examined with onboard Parsivel disdrometer measurements collected during marine surveys from 2012 to 2016. The observed rainfall is d... Raindrop size distribution (RSD) characteristics over the South China Sea (SCS) are examined with onboard Parsivel disdrometer measurements collected during marine surveys from 2012 to 2016. The observed rainfall is divided into premonsoon, monsoon, and post-monsoon periods based on the different large-scale circumstances. In addition to disdrometer data, sounding observation, FY-2E satellite, SPRINTARS (Spectral Radiation-Transport Model for Aerosol Species), and NCEP reanalysis datasets are used to illustrate the dynamical and microphysical characteristics associated with the rainfall in different periods. Significant variations have been observed in respect of raindrops among the three periods. Intercomparison reveals that small drops (D < 1 mm) are prevalent during pre-monsoon precipitation, whereas medium drops (1?3 mm) are predominant in monsoon precipitation. Overall, the post-monsoon precipitation is characterized by the least concentration of raindrops among the three periods. But, several large raindrops could also occur due to severe convective precipitation events in this period. Classification of the precipitation into stratiform and convective regimes shows that the lg(Nw) value of convective rainfall is the largest (smallest) in the pre-monsoon (post-monsoon) period, whereas the Dm value is the smallest (largest) in the pre-monsoon (post-monsoon) period. An inversion relationship between the coefficient A and the exponential b of the Z?R relationships for precipitation during the three periods is found. Empirical relations between Dm and the radar reflectivity factors at Ku and Ka bands are also derived to improve the rainfall retrieval algorithms over the SCS. Furthermore, the possible causative mechanisms for the significant RSD variability in different periods are also discussed with respect to warm and cold rain processes, raindrop evaporation, convective activities, and other meteorological factors. 展开更多
关键词 PRECIPITATION RAINDROP size distribution South China Sea MONSOON period STRATIFORM and convective cloud
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Geomorphic features of Quaternary glaciation in the Taniantaweng Mountain, on the southeastern Qinghai-Tibet Plateau
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作者 ZHANG Wei CHAI Le +5 位作者 IAN S.Evans LIU Liang LI Ya-peng QIAO Jing-ru TANG Qian-yu SUN Bo 《山地科学学报:英文版》 SCIE CSCD 2019年第2期256-274,共19页
We present geomorphological evidence for multiple glacial fluctuations during the Quaternary in the Taniantaweng Mountain, which is situated at the transition zone of the southeastern Qinghai-Tibet Plateau and the Yun... We present geomorphological evidence for multiple glacial fluctuations during the Quaternary in the Taniantaweng Mountain, which is situated at the transition zone of the southeastern Qinghai-Tibet Plateau and the Yunnan-Guizhou Plateau. To reconstruct the history of glacial evolution during the Quaternary Glaciation, we present a ~13000 km~2 geomorphologic map(1:440,000) for the Quaternary glaciations, as well as three electron spin resonance(ESR) ages and three optically stimulated luminescence(OSL) ages from the landforms. By integrating these with ages from previous studies, four major glacial advances are identified during marine oxygen isotope stages(MIS) 6, 3, 2 and 1. This glacial chronology is in reasonable agreement with existing glacial chronologies from other parts of the Hengduan Mountains and surrounding mountains. Glaciers had extended to the Yuqu River during the glacial maximum advance(MIS 6), but became successively more restricted from MIS 3 to MIS 1. The glacial distribution show that precipitation brought by the south Asian monsoon might play a primary role in driving glacial advances during the last glacial period in the southeastern Qinghai-Tibet Plateau. 展开更多
关键词 Qinghai-Tibet Plateau Taniantaweng MOUNTAIN GLACIAL LANDFORM ESR DATING OSL DATING South Asian monsoon
Diurnal Variations of Precipitation over North China Regulated by the Mountain-plains Solenoid and Boundary-layer Inertial Oscillation 预览
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作者 He PAN Guixing CHEN 《大气科学进展:英文版》 SCIE CAS CSCD 2019年第8期863-884,共22页
The mountain-plains solenoid(MPS) and boundary-layer inertial oscillation(BLO) are two typical regional forcings at the diurnal time scale. Their relative role in regulating the diurnal variations of summer rainfall o... The mountain-plains solenoid(MPS) and boundary-layer inertial oscillation(BLO) are two typical regional forcings at the diurnal time scale. Their relative role in regulating the diurnal variations of summer rainfall over North China and their change under different monsoon conditions are studied using a 19-yr archive of satellite rainfall and reanalysis data. It is shown that both a strong MPS and BLO can increase nocturnal rainfall in the North China plains but exhibit evident regional differences. The MPS-induced nocturnal rainfall is relatively confined to the plains adjacent to mountains from late night to morning, due to the upward branch of the nighttime MPS. In contrast, the BLO-induced nocturnal rainfall strengthens from early evening and is more extensive in early morning over the open plains further east. The contrasting effect in the evening is related to the convergent(divergent) easterly anomaly in the plains under the BLO(MPS). The BLO also induces the relatively strong enhancement of moisture convergence and high humidity by the southerly anomaly at late night. On strong monsoon days, the nocturnal rainfall amount associated with the MPS and BLO increases considerably in the plains.Both regional forcings become effective in regulating the rainfall diurnal cycle with enhanced moisture convergence under monsoon conditions. Their induced diurnal amplitudes of moisture convergence can be comparable to the daily mean by monsoon flow. The regional forcings thus couple with monsoon flow to strengthen rainfall in the plains, particularly from late night to morning. The results highlight that a combination of regional and large-scale forcings can strongly regulate the warm-season climate. 展开更多
关键词 DIURNAL cycle NOCTURNAL rainfall REGIONAL forcings summer MONSOON REGIONAL climate
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Buried channels provide keys to infer Quaternary stratigraphic and paleo-environmental changes:A case study from the west coast of India 预览
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作者 K.M. Dubey A.K.Chaubey +1 位作者 V.P. Mahale S.M. Karisiddaiah 《地学前缘:英文版》 CAS CSCD 2019年第4期1577-1595,共19页
High resolution shallow seismic data was acquired from inner continental shelf of Goa,west coast of India to map underlying stratigraphic and buried geomorphic features of shelf strata.Seismic data revealed characteri... High resolution shallow seismic data was acquired from inner continental shelf of Goa,west coast of India to map underlying stratigraphic and buried geomorphic features of shelf strata.Seismic data revealed characteristic channel incisions beneath 4-15 m thick sediment layer and corresponds to multi cycle incisions.Stratigraphic analysis of these incision signatures reveals three prominent subaerial unconformities S6,S7 and S9.These unconformities were exposed during the last glacial,penultimate glacial(MIS-6)and prior to penultimate glacial(MIS-8)periods.On the basis of interpreted age of subaerial unconformities and differences in their morphological features,observed channel incisions have been divided grossly into three phases of incision.Phase-1 incisions are older than~330 kyr BP,whereas,incisions of Phase-2 and Phase-3 correspond to~320-125 kyr BP and~115-10 kyr BP respectively.Plan form of these incisions varied from a straight channel type to ingrown meander and then to anastomosing channel types.These channels meet at the confluence of present-day Mandovi and Zuari rivers.The confluence point has varied in due course of time because of cyclic incision and burial with repeated sea level fluctuations.The preserved main channel width varies from~100 m to 1000 m.and maximum channel depth reaches up to~35 m.Comparison of quantitative and qualitative morphologic results of different phases of incisions suggest that Phase-2 channels had~33%more mean bank full discharge than that of the Phase-3 channels.Phase-2 incisions had been carved in higher hydraulic energy condition as compared to Phase-3 incisions implying that the Indian summer monsoon was better during formative stages of Phase-2 incisions. 展开更多
关键词 BURIED CHANNELS Glacial period Indian summer monsoon QUATERNARY SEA-LEVEL Subaerial UNCONFORMITY West coast of India
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Altered trends in carbon uptake in China's terrestrial ecosystems under the enhanced summer monsoon and warming hiatus
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作者 Honglin He Shaoqiang Wang +23 位作者 Li Zhang Junbang Wang Xiaoli Ren Lei Zhou Shilong Piao Hao Yan Weimin Ju Fengxue Gu Shiyong Yu Yuanhe Yang Miaomiao Wang Zhongen Niu Rcmg Ge Huimin Yan Mei Huang Guoyi Zhou Yongfei Bai Zongqiang Xie Zhiyao Tang Bingfang Wu Leiming Zhang Nianpeng He Qiufeng Wang Guirui Yu 《国家科学评论:英文版》 CSCD 2019年第3期505-514,共10页
The carbon budgets in terrestrial ecosystems in China are strongly coupled with climate changes.Over the past decade,China has experienced dramatic climate changes characterized by enhanced summer monsoon and decelera... The carbon budgets in terrestrial ecosystems in China are strongly coupled with climate changes.Over the past decade,China has experienced dramatic climate changes characterized by enhanced summer monsoon and decelerated warming.However,the changes in the trends of terrestrial net ecosystem production(NEP)in China under climate changes are not well documented.Here,we used three ecosystem models to simulate the spatiotemporal variations in China's NEP during 1982–2010 and quantify the contribution of the strengthened summer monsoon and warming hiatus to the NEP variations in four distinct climatic regions of the country.Our results revealed a decadal-scale shift in NEP from a downtrend of–5.95 Tg C/yr^2(reduced sink)during 1982–2000 to an uptrend of 14.22 Tg C/yr^2(enhanced sink)during 2000–10.This shift was essentially induced by the strengthened summer monsoon,which stimulated carbon uptake,and the warming hiatus,which lessened the decrease in the NEP trend.Compared to the contribution of 56.3%by the climate effect,atmospheric CO2 concentration and nitrogen deposition had relatively small contributions(8.6 and 11.3%,respectively)to the shift.In conclusion,within the context of the global-warming hiatus,the strengthening of the summer monsoon is a critical climate factor that enhances carbon uptake in China due to the asymmetric response of photosynthesis and respiration.Our study not only revealed the shift in ecosystem carbon sequestration in China in recent decades,but also provides some insight for understanding ecosystem carbon dynamics in other monsoonal areas. 展开更多
关键词 climate change Asian summer MONSOON WARMING HIATUS BIOGEOCHEMICAL modeling ecosystem carbon dynamics
"新三届"考生的高考记忆
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作者 孙佳慧 《汉语世界:英文版》 2019年第4期74-76,共3页
For most Chinese, the national college entrance exam (gaokao) is a uniwrsal--if not exactly fondly remembered-summer memory indelibly associated with baking heat or monsoon rain.
关键词 For MOST Chinese MONSOON RAIN the national COLLEGE ENTRANCE exam(gaokao)
末次冰盛期青藏高原冰川变化对亚洲气候的影响 预览
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作者 毋宇斌 刘永岗 +1 位作者 易朝路 刘鹏 《北京大学学报:自然科学版》 CAS CSCD 北大核心 2019年第1期159-170,共12页
以末次冰盛期(约2.6~1.9万年前)的气候为背景,利用大气模式CAM4耦合陆面模式CLM4,对青藏高原冰川规模扩大对气候产生的影响进行研究。结果表明,末次冰盛期青藏高原冰川对北半球夏季的气候影响较显著,除在冰川分布区引起显著的降温外,通... 以末次冰盛期(约2.6~1.9万年前)的气候为背景,利用大气模式CAM4耦合陆面模式CLM4,对青藏高原冰川规模扩大对气候产生的影响进行研究。结果表明,末次冰盛期青藏高原冰川对北半球夏季的气候影响较显著,除在冰川分布区引起显著的降温外,通过遥相关作用,还使得白令海峡附近显著升温。另外,冰川产生的扰动会显著地增强南亚夏季风,增加南亚地区降水。对比末次冰盛期与工业革命前时期不同气候态下青藏高原冰川规模扩大对气候的影响,发现工业革命前时期的影响显著小于末次冰盛期,说明青藏高原冰川对气候的影响与背景气候态有关。 展开更多
关键词 古气候模拟 青藏高原冰川 末次冰盛期 季风 遥相关
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Why Is the East Asian Summer Monsoon Extremely Strong in 2018?--Collaborative Effects of SST and Snow Cover Anomalies
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作者 Lijuan CHEN Wei GU Weijing LI 《气象学报:英文版》 SCIE CSCD 2019年第4期593-608,共16页
In 2018,summer precipitation was above normal in North and Northwest China and below normal around the Yangtze River valley,due to an extremely strong East Asian summer monsoon(EASM).The atmospheric circulation anomal... In 2018,summer precipitation was above normal in North and Northwest China and below normal around the Yangtze River valley,due to an extremely strong East Asian summer monsoon(EASM).The atmospheric circulation anomalies in East Asia and key external forcing factors that influence the EASM in 2018 are explored in this paper.The results show that there existed an anomalous cyclonic circulation near the Philippines,while the western Pacific subtropical high was located more northward than its normal position.In the mid–high latitudes,a negative geopotential height anomaly center was found near the Ural Mountains,suppressing the blocking activity.Under such a circulation pattern,precipitation near the Yangtze River valley decreased because local divergence and subsidence intensified,whereas precipitation in northern China increased due to large amounts of water vapor transport by anomalously strong southerly winds.Further analyses reveal that the strong EASM circulation in 2018 might result from the joint influences of several external forcing factors.The weak La Ni?a event that started from October 2017,the positive North Atlantic Tripolar mode(NAT)in spring 2018,and the reduced snow cover over the Tibetan Plateau in winter 2017/18 all collaboratively contributed to formation of the cyclonic circulation anomaly near the Philippines,leading to the extremely strong EASM.Especially,the positive NAT and the reduced Tibetan snow cover may have caused the negative geopotential height anomaly near the Ural Mountains,in favor of a strong EASM.The above external factors and their reinforcing impacts on the EASM are further verified by two groups of similar historical cases. 展开更多
关键词 East Asian summer monsoon external forcing factors La Nina North Atlantic Tripolar mode IndianOcean basin mode snow cover of the Tibetan Plateau
季风与西风对青藏高原全新世气候变化的影响:同位素证据
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作者 李秀美 侯居峙 +1 位作者 王明达 贺跃 《第四纪研究》 CAS CSCD 北大核心 2019年第3期678-686,共9页
青藏高原气候变化在冰期-间冰期、千年、十年际和季节尺度上受亚洲季风和西风环流的交互影响,表现出显著的区域性特征。然而全新世以来青藏高原气候变化的机制还不甚清楚,主要原因之一是缺少指示意义明确的古气候代用指标。课题组近年... 青藏高原气候变化在冰期-间冰期、千年、十年际和季节尺度上受亚洲季风和西风环流的交互影响,表现出显著的区域性特征。然而全新世以来青藏高原气候变化的机制还不甚清楚,主要原因之一是缺少指示意义明确的古气候代用指标。课题组近年来利用叶蜡氢同位素(δDwax)重建了高原东北部的青海湖、中北部的令戈错、中部的达则错、西部的班公错和阿翁错不同时间尺度的大气降水同位素记录,本文对上述工作进行总结,并结合青藏高原全新世以来已发表的其他地点的同位素和古水文记录,揭示全新世以来季风与西风对青藏高原不同区域气候变化的影响。结果表明:1)早全新世青海湖、令戈错、班公错和阿翁错4个湖泊均主要受夏季风影响,夏季风可以影响到青藏高原的大部分地区,此时夏季风在青藏高原的最北界限可能位于青海湖以北、克鲁克湖以南。2)中全新世青海湖、班公错和阿翁错受夏季风影响逐渐减弱;然而令戈错在7.0~4.5 ka水汽主要来源于西风环流。3)晚全新世青海湖和班公错受季风的影响进一步减弱;西风在3.5~1.7 ka和2.0~1.0 ka分别影响到高原中部的令戈错和达则错;晚全新世阿翁错受冰川融水补给影响降水同位素异常偏负。4)本研究表明在中晚全新世季风较弱的时期,西风能够深入到青藏高原内部地区,给高原内部地区带来冷湿的水汽。 展开更多
关键词 青藏高原 全新世 湖泊沉积物叶蜡 季风 西风 降水同位素
Continental drift, plateau uplift, and the evolutions of monsoon and arid regions in Asia, Africa, and Australia during the Cenozoic
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作者 Xiaodong LIU Buwen DONG +2 位作者 Zhi-Yong YIN Robin S. SMITH Qingchun GUO 《中国科学:地球科学英文版》 SCIE EI CAS CSCD 2019年第7期1053-1075,共23页
Monsoon and arid regions in the Asia-Africa-Australia (A-A-A) realm occupy more than 60% of the total area of these continents. Geological evidence showed that significant changes occurred to the A-A-A environments of... Monsoon and arid regions in the Asia-Africa-Australia (A-A-A) realm occupy more than 60% of the total area of these continents. Geological evidence showed that significant changes occurred to the A-A-A environments of the monsoon and arid regions, the land-ocean configuration in the Eastern Hemisphere, and the topography of the Tibetan Plateau (TP) in the Cenozoic. Motivated by this background, numerical experiments for 5 typical geological periods during the Cenozoic were conducted using a coupled ocean-atmosphere general circulation model to systemically explore the formations and evolutionary histories of the Ceno zoic A-A-A monso on and arid regions un der the influences of contine ntal drift and plateau uplift. Results of the nu merical experime nts indicate that the timings and causes of the formations of monsoon and arid regi ons in the A-A-A realm were very different. The northern and southern African monsoons existed during the mid-Paleocene, while the South Asian monsoon appeared in the Eocene after the Indian Subcontinent moved into the tropical Northern Hemisphere. In contrast, the East Asian mon soon and northern Australian monso on were established much later in the Miocene. The establishment of the tropical monsoons in northern and southern Africa, South Asia, and Australia were determined by both the continental drift and seas onal migratio n of the In ter-Tropical Convergence Zone (ITCZ), while the position and height of the TP were the key factor for the establishment of the East Asian monsoon. The presence of the subtropical arid regions in northern and southern Africa, Asia, and Australia depended on the positions of the continents and the control of the planetary scale subtropical high pressure zones, while the arid regions in the Arabian Peninsula and West Asia were closely related to the retreat of the Paratethys Sea. The formation of the mid-latitude arid region in the Asian interior, on the other hand, was the consequence of the uplift of the TP. These results from this study provide insi 展开更多
关键词 CENOZOIC MONSOON REGION ARID REGION Continental drift Tibetan Plateau UPLIFT Climate simulation
Intraseasonal Oscillation of Tropospheric Ozone over the Indian Summer Monsoon Region 预览
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作者 Yuli ZHANG Chuanxi LIU +1 位作者 Yi LIU Rui YANG 《大气科学进展:英文版》 SCIE CAS CSCD 2019年第4期417-430,共14页
Boreal summer intraseasonal oscillation(BSISO)of lower tropospheric ozone is observed in the Indian summer monsoon(ISM)region on the basis of ERA-Interim reanalysis data and ozonesonde data from the World Ozone and Ul... Boreal summer intraseasonal oscillation(BSISO)of lower tropospheric ozone is observed in the Indian summer monsoon(ISM)region on the basis of ERA-Interim reanalysis data and ozonesonde data from the World Ozone and Ultraviolet Radiation Data Centre.The 30–60-day intraseasonal variation of lower-tropospheric ozone shows a northwest–southeast pattern with northeastward propagation in the ISM region.The most significant ozone variations are observed in the Maritime Continent and western North Pacific.In the tropics,ozone anomalies extend from the surface to 300 hPa;however,in extratropical areas,it is mainly observed under 500 hPa.Precipitation caused by BSISO plays a dominant role in modulating the BSISO of lower-tropospheric ozone in the tropics,causing negative/positive ozone anomalies in phases 1–3/5–6.As the BSISO propagates northeastward to the western North Pacific,horizontal transport becomes relatively more important,increasing/reducing tropospheric ozone via anticyclonic/cyclonic anomalies over the western North Pacific in phases 3–4/7–8.As two extreme conditions of the ISM,most of its active/break events occur in BSISO phases 4–7/1–8 when suppressed /enhanced convection appears over the equatorial eastern Indian Ocean and enhanced/suppressed convection appears over India,the Bay of Bengal,and the South China Sea.As a result,the BSISO of tropospheric ozone shows significant positive /negative anomalies over the Maritime Continent,as well as negative/positive anomalies over India,the Bay of Bengal,and the South China Sea in active/break spells of the ISM.This BSISO of tropospheric ozone is more remarkable in break spells than in active spells of the ISM,due to the stronger amplitude of BSISO in the former. 展开更多
关键词 BOREAL SUMMER INTRASEASONAL oscillation TROPOSPHERIC OZONE Indian SUMMER MONSOON active/break spell
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The East Asian Monsoon since the Last Glacial Maximum:Evidence from geological records in northern China
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作者 Shiling YANG Xinxin DONG Jule XIAO 《中国科学:地球科学英文版》 SCIE EI CAS CSCD 2019年第8期1181-1192,共12页
The impact of global warming on the climate of northern China has been investigated intensively, and the behavior of the East Asian monsoon during previous intervals of climatic warming may provide insight into future... The impact of global warming on the climate of northern China has been investigated intensively, and the behavior of the East Asian monsoon during previous intervals of climatic warming may provide insight into future changes. In this study, we use paleovegetation records from loess and lake sediments in the marginal zone of the East Asian summer monsoon(EASM) to reconstruct the EASM during the interval of warming from the Last Glacial Maximum(LGM) to the Holocene. The results show that during the LGM, desert steppe or dry steppe dominated much of northern China;in addition, the southeastern margin of the deserts east of the Helan Mountains had a distribution similar to that of the present-day, or was located slightly further south, due to the cold and dry climate caused by a strengthened East Asian winter monsoon(EAWM) and weakened EASM. During the last deglaciation, with the strengthening of the EASM and concomitant weakening of the EAWM, northern China gradually became humid. However, this trend was interrupted by abrupt cooling during the Heinrich 1(H1) and Younger Dryas(YD) events. The EASM intensified substantially during the Holocene, and the monsoon rain belt migrated at least 300 km northwestwards, which led to the substantial shrinking of the desert area in the central and eastern part of northern China, and to the large expansion of plants favored by warm and humid conditions. Paleoclimatic records from the marginal zone of the EASM all show that the EASM reached its peak in the mid-Holocene, and past global climatic warming significantly strengthened the EASM, thereby greatly improving the ecological environment in northern China. Thus, northern China is expected to become wetter as global warming continues. Finally, high resolution Holocene vegetation records are sparse compared with the numerous records on the orbital timescale, and there is a need for more studies of Holocene climatic variability on the centennial-to-decadal scale. 展开更多
关键词 East Asian MONSOON Last GLACIAL Maximum HOLOCENE PALEOVEGETATION Global warming
Influence of Indian Ocean Dipole on Tropical Cyclone Activityover Western North Pacific in Boreal Autumn 预览
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作者 ZHOU Qun WEI Lixin ZHANG Runyu 《中国海洋大学学报:英文版》 SCIE CAS CSCD 2019年第4期795-802,共8页
In this study, we investigated the influence of the Indian Ocean Dipole (IOD) on the interannual variability of tropical cyclone (TC) activity over the western North Pacific (WNP) during autumn (September November) fr... In this study, we investigated the influence of the Indian Ocean Dipole (IOD) on the interannual variability of tropical cyclone (TC) activity over the western North Pacific (WNP) during autumn (September November) from 1961 2015. We found the number of TCs making landfall in China to be significantly negatively correlated with the IOD index, which can be attributed to shifts in the location of TC formation together with the abnormal steering flow at 500 hPa. During negative IOD autumns, TC genesis regions move obviously westward due to the westward retreat of the WNP monsoon trough. The TC activity is remarkably enhanced near South China coastal areas, which is due to a contiguous 500-hPa subtropical ridge. In contrast, during positive IOD autumns, TC genesis positions obviously shift eastward and more TCs tend to exhibit recurvature around 130 E or a westward path south of 15 N led by an equatorward movement of the 500-hPa subtropical ridge with a break near 125 E. In our examination of large-scale circula- tion, we found a pair of equator-symmetric anticyclones in the lower troposphere resulting from variations in the large-scale Walker circulation induced by the anomalous sea surface temperature (SST) associated with a positive IOD. The resulting Philippines anti- cyclonic anomalies are closely related to the variability of the monsoon trough over the WNP region. Furthermore, the variations in the steering flow can be explained by the suppressed (enhanced) convective activities around the Philippines and the weakened (strengthened) local meridional circulation over East Asia in positive (negative) IOD years. 展开更多
关键词 IOD tropical CYCLONE activity western North Pacific MONSOON TROUGH
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季风对娘子关泉域降水与泉水流量的影响 预览
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作者 邱金枝 《哈尔滨商业大学学报:自然科学版》 CAS 2019年第2期157-166,共10页
一些学者已经通过研究得知印度夏季风,西北太平洋季风和东亚夏季风这三种季风都对娘子关泉域的降雨和泉水流量有着非常强的影响作用.为了揭示三种季风在季风期,非季风期对降水和泉水流量的作用,选址山西省娘子关泉,利用小波相干方法对季... 一些学者已经通过研究得知印度夏季风,西北太平洋季风和东亚夏季风这三种季风都对娘子关泉域的降雨和泉水流量有着非常强的影响作用.为了揭示三种季风在季风期,非季风期对降水和泉水流量的作用,选址山西省娘子关泉,利用小波相干方法对季风,非季风与降雨,泉水流量的相干性进行了分析.其中季风包括印度夏季风,西北太平洋季风和东亚夏季风.6月到9月为季风期,10月到5月为非季风期.小波分析结果表明三种季风在非季风期对降雨和泉水流量都有影响,并且通过对比相干系数可以得知,三种季风对降雨的作用更加强烈. 展开更多
关键词 小波相干 季风 泉水流量 降雨
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Boreal Summer Intraseasonal Oscillation in the Asian–Pacific Monsoon Region Simulated in CAMS-CSM
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作者 Yanjun QI Renhe ZHANG +2 位作者 Xinyao RONG Jian LI Lun LI 《气象学报:英文版》 SCIE CSCD 2019年第1期66-79,共14页
The boreal summer intraseasonal oscillation(BSISO) is simulated by the Climate System Model(CSM) developed at the Chinese Academy of Meteorological Sciences(CAMS), China Meteorological Administration. Firstly, the res... The boreal summer intraseasonal oscillation(BSISO) is simulated by the Climate System Model(CSM) developed at the Chinese Academy of Meteorological Sciences(CAMS), China Meteorological Administration. Firstly, the results indicate that this new model is able to reasonably simulate the annual cycle and seasonal mean of the precipitation, as well as the vertical shear of large-scale zonal wind in the tropics. The model also reproduces the eastward and northward propagating oscillation signals similar to those found in observations. The simulation of BSISO is generally in agreement with the observations in terms of variance center, periodicity, and propagation, with the exception that the magnitude of BSISO anomalous convections are underestimated during both its eastward propagation along the equator and its northward propagation over the Asian–Pacific summer monsoon region. Our preliminary evaluation of the simulated BSISO by CAMS-CSM suggests that this new model has the capability, to a certain extent, to capture the BSISO features, including its propagation zonally along the equator and meridionally over the Asian monsoon region. 展开更多
关键词 CAMS-CSM boreal SUMMER intraseasonal oscillation(BSISO) Asian–Pacific SUMMER monsoon region
MOISTURE TRANSPORT PATHS AND SOURCES OF SOUTH CHINA ANNUALLY FIRST RAINY SEASON AND THEIR RELATIONSHIP WITH THE ONSET OF THE SOUTH CHINA SEA SUMMER MONSOON
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作者 李晓帆 江志红 施逸 《热带气象学报:英文版》 SCIE 2019年第2期171-179,共9页
This study simulated the moisture transport process of southern China annually first rainy season(SCAFRS)using a Lagrangian airflow trajectory model(Hybrid Single Particle Lagrangian Integrated Trajectory: HYSPLIT), t... This study simulated the moisture transport process of southern China annually first rainy season(SCAFRS)using a Lagrangian airflow trajectory model(Hybrid Single Particle Lagrangian Integrated Trajectory: HYSPLIT), to determine SCAFRS moisture transport characteristics and their relationship with South China Sea summer monsoon(SCSSM). It is found that the moisture transport paths and sources of SCAFRS are closely related to the onset of SCSSM. Divided by SCSSM onset dates, the moisture transport characteristics of SCAFRS are compared quantitatively.Before the onset of SCSSM, precipitation of SCAFRS mainly comes from western Pacific and eastern China. Their contributions are 24% and 25%, respectively. The amount of water vapor carried along the path coming from Bay of Bengal-South China Sea(BSC) is relatively high, but the contribution rate of this path to SCAFRS precipitation is relatively low. Mainly due to strong precipitation over Bay of Bengal before the onset of SCSSM, this region is a moisture sink, which makes most moisture deposit in this region and only a small portion of water vapor transported to southern China. After the onset of SCSSM, most water vapor is transported to southern China by the southwesterly paths. The Indian Ocean is the main moisture source, which contributes almost 25% to SCAFRS precipitation. The contributions of moisture originating from BSC and eastern China to southern China precipitation after the onset of SCSSM are 21% and 18%, respectively. 展开更多
关键词 moisture transport Lagrangian method southern China annually FIRST RAINY season ONSET of the South China Sea summer monsoon
LASG Global AGCM with a Two-moment Cloud Microphysics Scheme:Energy Balance and Cloud Radiative Forcing Characteristics 预览
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作者 Lei WANG Qing BAO +9 位作者 Wei-Chyung WANG Yimin LIU Guo-Xiong WU Linjiong ZHOU JiANDong LI Hua GONG Guokui NIAN Jinxiao LI Xiaocong WANG Bian HE 《大气科学进展:英文版》 SCIE CAS CSCD 2019年第7期697-710,共14页
Cloud dominates influence factors of atmospheric radiation, while aerosol–cloud interactions are of vital importance in its spatiotemporal distribution. In this study, a two-moment(mass and number) cloud microphysics... Cloud dominates influence factors of atmospheric radiation, while aerosol–cloud interactions are of vital importance in its spatiotemporal distribution. In this study, a two-moment(mass and number) cloud microphysics scheme, which significantly improved the treatment of the coupled processes of aerosols and clouds, was incorporated into version 1.1 of the IAP/LASG global Finite-volume Atmospheric Model(FAMIL1.1). For illustrative purposes, the characteristics of the energy balance and cloud radiative forcing(CRF) in an AMIP-type simulation with prescribed aerosols were compared with those in observational/reanalysis data. Even within the constraints of the prescribed aerosol mass, the model simulated global mean energy balance at the top of the atmosphere(TOA) and at the Earth’s surface, as well as their seasonal variation, are in good agreement with the observational data. The maximum deviation terms lie in the surface downwelling longwave radiation and surface latent heat flux, which are 3.5 W m-2(1%) and 3 W m-2(3.5%), individually. The spatial correlations of the annual TOA net radiation flux and the net CRF between simulation and observation were around 0.97 and 0.90, respectively. A major weakness is that FAMIL1.1 predicts more liquid water content and less ice water content over most oceans. Detailed comparisons are presented for a number of regions, with a focus on the Asian monsoon region(AMR). The results indicate that FAMIL1.1 well reproduces the summer–winter contrast for both the geographical distribution of the longwave CRF and shortwave CRF over the AMR. Finally, the model bias and possible solutions, as well as further works to develop FAMIL1.1 are discussed. 展开更多
关键词 two-moment CLOUD MICROPHYSICS SCHEME aerosol–cloud interactions energy balance CLOUD radiative forcing Asian monsoon region
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钦州湾溢油数值模块及其应用
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作者 吴桂丹 朱冬琳 高劲松 《海洋湖沼通报》 CSCD 北大核心 2019年第2期24-31,共8页
本文应用水动力模型及溢油模块对代表性风况下钦州湾金鼓江的溢油事故进行情景模拟,且水动力模型结果与实测潮位和实测潮流吻合较好。低潮时发生溢油,不同风况下油粒子在5.5-8.5h后漂到金鼓江上游养殖区。高潮时发生溢油,油粒子在不同... 本文应用水动力模型及溢油模块对代表性风况下钦州湾金鼓江的溢油事故进行情景模拟,且水动力模型结果与实测潮位和实测潮流吻合较好。低潮时发生溢油,不同风况下油粒子在5.5-8.5h后漂到金鼓江上游养殖区。高潮时发生溢油,油粒子在不同风况下漂移轨迹差别较大,例如无风时油粒子在钦州湾颈和三墩外海附近往复运动,而南风3.3m/s工况下油粒子将最终影响大榄坪港区的东南端。另外,高风速下不利风向会缩减油膜抵达敏感区的时间,同时风速越大,蒸发越快。因此风场对溢油模型有重要意义,今后将在精细化WRF模型基础上优化溢油模型并构建溢油决策系统,为地方经济发展和海洋环境保护提供科技支撑。 展开更多
关键词 金鼓江 MIKE模型 溢油模块 潮流 季风
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