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The Dynamic Plateau Monsoon Index and Its Association with General Circulation Anomalies 被引量:17
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作者 荀学义 胡泽勇 马耀明 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2012年第6期1249-1263,共15页
Based on monthly ECMWF reanalysis-Interim (ERA-Interim) reanalysis data, along with monthly precipitation and temperature data, the Dynamic Plateau Monsoon Index (DPMI) is defined. The results of a contrast analys... Based on monthly ECMWF reanalysis-Interim (ERA-Interim) reanalysis data, along with monthly precipitation and temperature data, the Dynamic Plateau Monsoon Index (DPMI) is defined. The results of a contrast analysis of the DPMI versus the Traditional Plateau Monsoon Index (TPMI) are described. The response of general circulation to northern Qinghai-Xizang Plateau summer monsoon anomalies and the correlation of the DPMI with general circulation anomalies are investigated. The results show that, the DPMI reflected meteorological elements better and depicted climate variation more accurately than the TPMI. In years when the plateau summer monsoon is strong, the low over the plateau and the trough near the eastern coast of Asia are deeper and higher than normal over South China. This correlation corresponds to two anomalous cyclones over the plateau and the eastern coast of Asia and an anomalous anticyclone in South China. The plateau and its adjacent regions are affected by anomalous southwesterly winds that transport more moisture to South China and cause more precipitation. The lower reaches of the Yangtze River appear to receive more precipitation by means of the strong westerly water vapor flow transported from the "large triangle affecting the region". In years when the plateau summer monsoon is weak, these are opposite. The plateau monsoon is closely related to the intensity and position of the South Asian high, and the existence of a teleconnection pattern in the mid-upper levels suggests a possible linkage of the East Asian monsoon and the Indian monsoon to the plateau summer monsoon. 展开更多
关键词 Qinghai-Xizang plateau Dynamic plateau monsoon Index center position general circulation
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Interannual and Decadal Variations of Snow Cover overQinghai-Xizang Plateau and Their Relationships to Summer Monsoon Rainfall in China 被引量:51
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作者 陈烈庭 吴仁广 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2000年第1期18-30,共13页
Interannual and decadal variations of winter snow cover over the Qinghai-Xizang Plateau (QXP) are analyzed by using monthly mean snow depth data set of 60 stations over QXP for the period of 1958 through 1992. It is f... Interannual and decadal variations of winter snow cover over the Qinghai-Xizang Plateau (QXP) are analyzed by using monthly mean snow depth data set of 60 stations over QXP for the period of 1958 through 1992. It is found that the winter snow cover over QXP bears a pronounced quasi-biennial oscillation, and it underwent an obvious decadal transition from a poor snow cover period to a rich snow cover period in the late 1970’s during the last 40 years. It is shown that the summer rainfall in the eastern China is closely associated with the winter snow cov-er over QXP not only in the interannual variation but also in the decadal variation. A clear relationship ex-ists in the quasi-biennial oscillation between the summer rainfall in the northern part of North China and the southern China and the winter snow cover over QXP. Furthermore, the summer rainfall in the four cli-mate divisions of Qinling-Daba Mountains, the Yangtze-Huaihe River Plain, the upper and lower reaches of the Yangtze River showed a remarkable transition from drought period to rainy period in the end of 1970’s, in good correspondence with the decadal transition of the winter snow cover over QXP. Key words Snow cover over Qinghai-Xizang Plateau - Summer monsoon rainfall in China - Interannual and decadal variations This study was supported by the National Key Programme for Developing Basic Sciences (G 1998040900 Part I). 展开更多
关键词 Snow cover over Qinghai-Xizang plateau Summer monsoon rainfall in China Interannual and decadal variations
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A Modeling Study of the Effects of Anomalous Snow Cover over the Tibetan Plateau upon the South Asian Summer Monsoon 被引量:10
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作者 刘华强 孙照渤 +1 位作者 王举 闵锦忠 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2004年第6期964-975,共12页
The e?ect of anomalous snow cover over the Tibetan Plateau upon the South Asian summer monsoon is investigated by numerical simulations using the NCAR regional climate model (RegCM2) into which gravity wave ... The e?ect of anomalous snow cover over the Tibetan Plateau upon the South Asian summer monsoon is investigated by numerical simulations using the NCAR regional climate model (RegCM2) into which gravity wave drag has been introduced. The simulations adopt relatively realistic snow mass forcings based on Scanning Multi-channel Microwave Radiometer (SMMR) pentad snow depth data. The physical mechanism and spatial structure of the sensitivity of the South Asian early summer monsoon to snow cover anomaly over the Tibetan Plateau are revealed. The main results are summarized as follows. The heavier than normal snow cover over the Plateau can obviously reduce the shortwave radiation absorbed by surface through the albedo e?ect, which is compensated by weaker upward sensible heat ?ux associated with colder surface temperature, whereas the e?ects of snow melting and evaporation are relatively smaller. The anomalies of surface heat ?uxes can last until June and become unobvious in July. The decrease of the Plateau surface temperature caused by heavier snow cover reaches its maximum value from late April to early May. The atmospheric cooling in the mid-upper troposphere over the Plateau and its surrounding areas is most obvious in May and can keep a fairly strong intensity in June. In contrast, there is warming to the south of the Plateau in the mid-lower troposphere from April to June with a maximum value in May. The heavier snow cover over the Plateau can reduce the intensity of the South Asian summer monsoon and rainfall to some extent, but this in?uence is only obvious in early summer and almost disappears in later stages. 展开更多
关键词 snow cover Tibetan plateau South Asian monsoon numerical simulation
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STABLE ISOTOPE IN PRECIPITATION IN THE SOUTHERN TIBETAN PLATEAU REVEALING STRONG SIGNAL OF MONSOON PRECIPITATION 被引量:1
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作者 Tian Lide, Yao Tandong, Pu Jianchen, Sun Wenzhen 《地学前缘》 EI CAS CSCD 2000年第S1期395-395,共1页
Continuous precipitation was sampled at several stations in the southern Tibetan plateau to study the variation of stable isotope in precipitation. Our work shows that there is a strong signal of monsoon precipitation... Continuous precipitation was sampled at several stations in the southern Tibetan plateau to study the variation of stable isotope in precipitation. Our work shows that there is a strong signal of monsoon precipitation in the stable isotope of precipitation, which is quite different from that in other regions in the Tibetan plateau. The spatial variation, the seasonal variation of δ 18 O and the relationship between δ 18 O in precipitation and local meteorological parameters are all affected by monsoon precipitation in the south of Tibetan plateau.From the spatial variation, precipitation samples were collected from a dozen stations from south to north of the Tibetan plateau. A strong spatial variation of stable isotope in precipitation has been found. Extremely low value of δ 18 O in precipitation in the south of Tibetan plateau can be seen which can be contributed to the monsoon precipitation in the south of Tibetan plateau. The strong precipitation in the south slope of Himalayas Mts. depleted heavily the heavy stable isotope which resulting in very low δ 18 O in precipitation in the south of Tibetan plateau. This work also shows that the monsoon precipitation can affect effectively as far as to the Tanggula Mts. in the middle of the Tibetan plateau. 展开更多
关键词 stable ISOTOPES PRECIPITATION TIBETAN plateau monsoon
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Formation of the Summertime Ozone Valley over the Tibetan Plateau:The Asian Summer Monsoon and Air Column Variations 被引量:19
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作者 卞建春 严仁嫦 +2 位作者 陈洪滨 吕达仁 Steven T.MASSIE 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2011年第6期1318-1325,共8页
The summertime ozone valley over the Tibetan Plateau is formed by two influences,the Asian summer monsoon(ASM) and air column variations.Total ozone over the Tibetan Plateau in summer was ~33 Dobson units(DU) low... The summertime ozone valley over the Tibetan Plateau is formed by two influences,the Asian summer monsoon(ASM) and air column variations.Total ozone over the Tibetan Plateau in summer was ~33 Dobson units(DU) lower than zonal mean values over the ocean at the same latitudes during the study period 2005-2009.Satellite observations of ozone profiles show that ozone concentrations over the ASM region have lower values in the upper troposphere and lower stratosphere(UTLS) than over the non-ASM region.This is caused by frequent convective transport of low-ozone air from the lower troposphere to the UTLS region combined with trapping by the South Asian High.This offset contributes to a ~20-DU deficit in the ozone column over the ASM region.In addition,along the same latitude,total ozone changes identically with variations of the terrain height,showing a high correlation with terrain heights over the ASM region,which includes both the Tibetan and Iranian plateaus.This is confirmed by the fact that the Tibetan and Iranian plateaus have very similar vertical distributions of ozone in the UTLS,but they have different terrain heights and different total-column ozone levels.These two factors(lower UTLS ozone and higher terrain height) imply 40 DU in the lower-ozone column,but the Tibetan Plateau ozone column is only ~33 DU lower than that over the non-ASM region.This fact suggests that the lower troposphere has higher ozone concentrations over the ASM region than elsewhere at the same latitude,contributing ~7 DU of total ozone,which is consistent with ozonesonde and satellite observations. 展开更多
关键词 Asian summer monsoon Tibetan plateau air column variation ozone valley
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The Influence of Tibetan Plateau on the Interannual Variability of Asian Monsoon 被引量:30
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作者 吴爱明 倪允琪 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 1997年第4期60-73,共14页
Forced by the realistic SST, an atmospheric general circulation model (AGCM) with 9 sigma levels in vertical and rhomboidal truncation at wave number 15 in the horizontal is run for 16 years with and without the Tibet... Forced by the realistic SST, an atmospheric general circulation model (AGCM) with 9 sigma levels in vertical and rhomboidal truncation at wave number 15 in the horizontal is run for 16 years with and without the Tibetan Plateau respectively(called TP and NTP experiment). The result simulated is used to investigate the influence of the Tibetan Plateau on the interannual variability of Asian monsoon. It is found that the interannual variability of Asian monsoon associated with El Nino/La Nina in NTP experiment is quite different from that in TP experiment. With the Tibetan Plateau included, the results are consistent with the observation very well. To a great extent, the anomalous variation of Asian monsoon during El Nino/La Nina period in observation is due to the existence of the Tibetan Plateau. Therefore, the topography of the Tibetan Plateau is an important factor to the interannual variability of Asian monsoon. 展开更多
关键词 AGCMs Orography of Tibetan plateau Interannual Variability of Asian monsoon El Nino/La Nina
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A Possible Impact of Cooling over the Tibetan Plateau on the Mid-Holocene East Asian Monsoon Climate 被引量:5
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作者 靳立亚 王会军 +1 位作者 陈发虎 姜大膀 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2006年第4期543-550,共8页
By using a 9-level global atmospheric general circulation model developed at the Institute of Atmospheric Physics (IAP9L-AGCM) under the Chinese Academy of Sciences, the authors investigated the response of the East... By using a 9-level global atmospheric general circulation model developed at the Institute of Atmospheric Physics (IAP9L-AGCM) under the Chinese Academy of Sciences, the authors investigated the response of the East Asian monsoon climate to changes both in orbital forcing and the snow and glaciers over the Tibetan Plateau at the mid-Holocene, about 6000 calendar years before the present (6 kyr BP). With the Earth's orbital parameters appropriate for the mid-Holocene, the IAP9L-AGCM computed warmer and wetter conditions in boreal summer than for the present day. Under the precondition of continental snow and glacier cover existing over part of the Tibetan Plateau at the mid-Holocene, the authors examined the regional climate response to the Tibetan Plateau cooling. The simulations indicated that climate changes in South Asia and parts of central Asia as well as in East Asia are sensitive to the Tibetan Plateau cooling at the mid-Holocene, showing a significant decrease in precipitation in northern India, northern China and southern Mongolia and an increase in Southeast Asia during boreal summer. The latter seems to correspond to the weakening, southeastward shift of the Asian summer monsoon system resulting from reduced heat contrast between the Eurasian continent and the Pacific and Indian Oceans when a cooling over the Tibetan Plateau was imposed. The simulation results suggest that the snow and glacier environment over the Tibetan Plateau is an important factor for mid-Holocene climate change in the areas highly influenced by the Asian monsoon. 展开更多
关键词 paleoclimate modeling East Asian summer monsoon MID-HOLOCENE Tibetan plateau snow and glaciers
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DECOUPLED SUMMER AND WINTER MONSOON IN NORTHEAST TIBET AND NORTHWEST LOESS PLATEAU DURING THE LAST INTERGLACIATION
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作者 Lu Huayu 1, Miao Xiaodong 1,Ma Haizhou 2, Sun Youbin 1, Cao Guangchao 2(1 State Key Laboratory of Loess and Quaternary Geology, Chinese Academy of S ciences. Xian 710054, China,E\|mail:luhy@loess.llqg.an.cn 2 Department of Geography, Qinghai No 《地学前缘》 EI CAS CSCD 2000年第S1期389-390,共2页
Modern meteorological observations have proved that climate change in the northeast Tibet plateau is characteristic of alternations of plateau summer and winter monsoons, and climate change in Chinese Loess plateau is... Modern meteorological observations have proved that climate change in the northeast Tibet plateau is characteristic of alternations of plateau summer and winter monsoons, and climate change in Chinese Loess plateau is geared by variations of East Asian summer and winter monsoon strengths. A transitional zone between regions dominated by plateau monsoon and East Asian monsoon respectively is located at around 110°E in China. The two monsoon systems are driven by different forcing aspects.Here we show the two climatic systems change during the last interglacial period (IG) by examining geological records. Two aeolian loess\|paleosol sequences,one is located in northeast Tibet plateau closed to Xining and the other one in the northwest Loess plateau closed to Huanxian, were investigated. Age frames of the paleosol and intercalated loess are achieved by Thermoluminescence dating, palaeomagnetic measurements and stratigraphy correlation. Samples taken from Huanxian section were at 5cm intervals, and samples from Xining section were taken at every 10cm. The samples were measured for magnetic susceptibility (MS), rubidium/strontium value (Rb/Sr), Calcium carbonate content (CaCO\-3) and grain\|size distribution (GS). Detail time scale is obtained by two steps. First, correlate MS curves with deep\|sea oxygen isotope time series of stage 4,5 and 6 of Martinson et al (1987) to assign ages of boundaries of stratigraphic units. Second, linearly interpolate ages between the obtained ages and therefore get age of each sampling point. 展开更多
关键词 TIBET plateau Chinese LOESS plateau SUMMER monsoon winter monsoon the LAST interglaciation
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The Combined Effect of Tibetan Plateau Uplift and Glacial-Interglacial Cycles on the Quaternary Evolution of the East Asian Monsoon: Evidence from South China Sea Sediments 被引量:1
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作者 MENG Xianwei LIU Yanguang +1 位作者 ZHANG Xiaodong ZHANG Jun 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2014年第2期661-668,共8页
The siliciclastic sediments of the uppermost section of 185 mcd (meters composite depth) from ODP Site 1146 on the northern continental slope of the South China Sea (SCS) were partitioned according to their source... The siliciclastic sediments of the uppermost section of 185 mcd (meters composite depth) from ODP Site 1146 on the northern continental slope of the South China Sea (SCS) were partitioned according to their sources using end-member modeling on grain-size data.The goal was to evaluate the evolution of the East Asian monsoon over the past 2 million years.The siliciclastic sediments were described as hybrids of four end-members,EM1,EM2,EM3,and EM4,with modal grain sizes of 8-22 μm,2-8 μm,31-125 μm,and 4-11 μm,respectively.EM1 and EM3 are interpreted as eolian dust and EM2 and EM4 as fluvial mud.The ratio of eolian dust to fluvial mud ((EM1+EM3)/(EM2+EM4)) is regarded as an indicator of the East Asian monsoon.The variation in this ratio not only shows periodical oscillations consistent with oxygen isotope stages,but also exhibits a phased increasing trend corresponding with the phased uplifts of the Tibetan Plateau,indicating that the evolution of the East Asian Monsoon was controlled not only by glacial-interglacial cycles,but also by the phased uplifts of the Tibetan Plateau during the Quaternary. 展开更多
关键词 East Asian monsoon South China Sea Tibetan plateau uplift glacial-interglacial cycle QUATERNARY
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REORGANIZATION OF THE ASIAN MONSOON SYSTEM AT ABOUT 2.6 Ma AGO AND ITS IMPLICATIONS FOR THE RISING OF THE TIBETAN PLATEAU
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作者 Wang Jian, Liu Zechun, Chen Ye, Huang Qiaohua 《地学前缘》 EI CAS CSCD 2000年第S1期393-393,共1页
More and more concentrations have been focused on the uplift of the Tibetan Plateau and its effects on regional and global environment. The development of Asian monsoon has a close relationship with the uplift of the ... More and more concentrations have been focused on the uplift of the Tibetan Plateau and its effects on regional and global environment. The development of Asian monsoon has a close relationship with the uplift of the Tibetan Plateau. The understanding for the development of Asian monsoon is the key to the understanding of the process and the mechanism of the environmental evolution of the Asian region and to the understanding of the history of the uplift of the Tibetan Plateau. It is found that a big change of the Asian monsoon system occurred at about 2 6Ma ago. The winter monsoon strengthened (Ding et al.,1992 ), the change of winter monsoon began to in the opposite phase to the summer monsoon in East Asia (An et al., 1998 ), the tropical Southwest monsoon was hard to influence the North China (Li, 1999). However, whether there were changes in direction of winter monsoon and strength of summer monsoon occurred and how to change are still not clear. In this paper, the changes of the Asian monsoon system at about 2 6Ma ago are discussed, based on the reanalysis and combination of the results of atmospheric simulations and the geological records existed. It is suggested that, at about 2 6Ma ago, both winter monsoon and summer monsoon strengthened obviously, because that the amplitude of the climatic change increased a lot—warmer during the warm periods and colder during the cold periods. The direction of winter monsoon in Northern China changed from North—West—West to Northwest or North—West—North, because that the expansion direction of eolian\|deposit\|distribution area in China changed from mainly eastward to mainly southward. The area influenced by subtropical monsoon increased, but the area influenced by tropical monsoon decreased in China, because of the rising of the Tibetan Plateau and the southwest\|ward migration of the center of the Asian Low. At some time of the Pliocene, the tropical monsoon had penetrated onto the Qinghai\|Xizang region and influenced on the North China and Northwest China. However, after 2.6Ma B.P., the effects of the tropical monsoon on Northwest China and the northern part of the Tibetan Plateau decreased. All these suggest that the Tibetan Plateau perhaps reached about 2000m elevation at about 2 6Ma B.P.. 展开更多
关键词 Asian monsoon Tibetan plateau China environmental changes PALAEOGEOGRAPHY PALAEOCLIMATOLOGY climatic change
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青藏高原水循环中高原低涡及多季风交汇的研究进展
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作者 华维 邓浩 +4 位作者 夏昌基 张永莉 朱丽华 赖欣 范广洲 《沙漠与绿洲气象》 2024年第2期1-11,共11页
青藏高原以其特殊而强大的动力和热力效应,导致东亚季风、印度季风和高原季风在高原及周边地区交汇。受多季风交汇影响,青藏高原低涡的水循环过程极为复杂,而高原低涡水循环异常往往可造成高原及周边乃至我国中东部地区频发灾害性天气,... 青藏高原以其特殊而强大的动力和热力效应,导致东亚季风、印度季风和高原季风在高原及周边地区交汇。受多季风交汇影响,青藏高原低涡的水循环过程极为复杂,而高原低涡水循环异常往往可造成高原及周边乃至我国中东部地区频发灾害性天气,因此一直是国内外学者关注的热点和难点问题。本文回顾了国内外关于高原低涡活动特征、结构特征、生成发展机制等方面研究进展,从高原低涡水汽输送、低涡降水和云—降水物理过程等角度概括了高原低涡参与水循环过程研究成果,在总结东亚季风、印度季风和高原季风相互作用研究的基础上分析了多季风交汇对高原水循环的影响。对多季风作用下高原低涡影响水循环方面存在的问题进行了讨论,并展望了未来研究方向。 展开更多
关键词 多季风交汇 高原低涡 水循环
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基于青藏高原和印度洋区域热力状况的气候预测先兆信号
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作者 肖子牛 李张群 +2 位作者 赵亮 陈红 冯蓉 《气候与环境研究》 CSCD 北大核心 2024年第2期216-228,共13页
围绕青藏高原和印度洋区域热力状况对南亚季风、水汽输送和区域气候的影响,本文梳理总结了相关研究进展,重点聚焦在青藏高原和印度洋区域热力状况和热力差异与季风活动、水汽输送等重要气候指标的联系,并据此提出了印度洋和高原区域在... 围绕青藏高原和印度洋区域热力状况对南亚季风、水汽输送和区域气候的影响,本文梳理总结了相关研究进展,重点聚焦在青藏高原和印度洋区域热力状况和热力差异与季风活动、水汽输送等重要气候指标的联系,并据此提出了印度洋和高原区域在次季节、季节尺度的气候预测指标和方法。对认识青藏高原和印度洋区域热力状况对气候的影响,改善该区域气候预测的能力具有参考意义。 展开更多
关键词 青藏高原 印度洋 热力状况 南亚季风 气候预测
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青藏高原—印度洋热力差对南亚季风活动的多尺度影响
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作者 肖子牛 李张群 《大气科学》 CSCD 北大核心 2024年第1期147-159,共13页
海陆热力差异是季风形成和演变的根本驱动力,青藏高原与印度洋热力差异是影响南亚季风活动的重要因素。本文围绕次季节、季节、年际和年代际等不同时间尺度上青藏高原与印度洋的热力差异对南亚季风活动的影响,回顾和总结了相关研究成果... 海陆热力差异是季风形成和演变的根本驱动力,青藏高原与印度洋热力差异是影响南亚季风活动的重要因素。本文围绕次季节、季节、年际和年代际等不同时间尺度上青藏高原与印度洋的热力差异对南亚季风活动的影响,回顾和总结了相关研究成果。在次季节尺度上,主要聚焦在两者的热力差异对南亚季风爆发的影响;在年际尺度上,着重阐释了其对南亚季风强度年际变化的指示意义;在年代际尺度上,考察了热力差异和南亚季风降水关系的年代际变化。同时,本文对该领域一些需要进一步研究的问题进行了讨论。 展开更多
关键词 热力差异 南亚季风 多时间尺度 季风降水 青藏高原 印度洋
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黄土高原古气候变化定量重建的新进展
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作者 孙有斌 卢红选 章泽科 《地质学报》 EI CAS CSCD 北大核心 2024年第3期1006-1023,共18页
中国黄土-红黏土沉积是可与深海沉积媲美的陆相沉积载体,记录了晚新生代东亚大陆气候环境变化历史。基于中国黄土的多种理化指标,重建了黄土高原地区构造-千年尺度东亚季风变化历史,为探讨区域与全球气候的联系提供了关键证据。近年来,... 中国黄土-红黏土沉积是可与深海沉积媲美的陆相沉积载体,记录了晚新生代东亚大陆气候环境变化历史。基于中国黄土的多种理化指标,重建了黄土高原地区构造-千年尺度东亚季风变化历史,为探讨区域与全球气候的联系提供了关键证据。近年来,黄土高原古气候变化研究逐步从定性描述拓展到定量重建,本文旨在回顾基于中国黄土定量重建古温度和古降雨变化取得的重要进展。首先,梳理了古气候要素定量重建的指标和方法,古温度重建指标包括植硅体、碳酸盐耦合同位素、微生物脂类代用指标等;古降水变化敏感指标包括磁化率、白云石/方解石含量、生物微钙体Sr/Ca比值、有机碳同位素以及^(10)Be等。然后,汇总了典型黄土剖面定量重建的古气候变化序列,分别从构造、轨道及千年时间尺度上探讨了古温度和古降雨的变化特征。结果表明,基于生标重建的不同时间跨度的土壤古温度变化序列,在冰期—间冰期尺度上的波动特征基本一致,但在冰盛期—冰消期时段出现了增温超前现象,说明陆地植被对土壤温度变化有重要调制作用。然而,不同指标重建的降水变化幅度差异较大,主导周期也存在差异,说明定量重建降水变化仍有较大挑战。最后,简要总结了黄土高原古气候定量重建存在的问题,明确了区分温度和降水季节性变化的重要性,指出加强地质记录与模拟结果的对比同化,将有助深化对多尺度季风变化动力学的理解。 展开更多
关键词 黄土高原 黄土-古土壤序列 古温度 古降水 东亚季风
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距今2000年青藏高原湖泊水位下降的区域特征及机理
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作者 王郁晗 安福元 刘向军 《海洋地质与第四纪地质》 CAS CSCD 北大核心 2024年第2期55-68,共14页
基于亚洲夏季风与西风的影响范围将青藏高原划分为3个研究区,通过对比湖泊沉积物中多代用指标与晚全新世火山活动、北半球温度和亚洲季风指数,探讨了2 kaBP前后高原湖泊水位下降的原因,并分析了不同区域湖泊对气候波动响应的空间差异。... 基于亚洲夏季风与西风的影响范围将青藏高原划分为3个研究区,通过对比湖泊沉积物中多代用指标与晚全新世火山活动、北半球温度和亚洲季风指数,探讨了2 kaBP前后高原湖泊水位下降的原因,并分析了不同区域湖泊对气候波动响应的空间差异。结果表明,青藏高原西南部湖面水位下降幅度大于西北部,更甚于高原东北部。这可能是因印度夏季风(Indian Summer Monsoon,简称ISM)强度减弱,高原西南部的湖泊更依赖于ISM降水的补给,因此对该季风所带来的水汽通量的减少更加敏感。而且,该时期的北大西洋涛动(North Atlantic Oscillation,简称NAO)的位相由负转正,使得青藏高原北部水汽辐合增强、降水偏多而南部降水偏少,进而导致高原南部湖面水位下降幅度普遍大于北部湖泊。导致青藏高原气候趋于冷干的主要原因,本文归因于该阶段厄尔尼诺(EI Niño)的加强。除此之外,该时期南半球环状模(Southern Annular Mode,简称SAM)冬夏季的不同位相也通过复杂的海气耦合过程,跨越赤道对青藏高原气候起到了降温减湿的作用。 展开更多
关键词 气候变化 青藏高原湖泊 印度夏季风 厄尔尼诺 北大西洋涛动
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青藏高原东南缘攀枝花市降水特征及其成因初探
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作者 李永军 卢萍 《暴雨灾害》 2024年第1期101-109,共9页
为更好地认识青藏高原东南缘地形复杂区降水特征及其成因,利用位于青藏高原东南缘的攀枝花市2015—2020年72个国家、区域气象观测站资料和欧洲中心0.25°×0.25°分辨率的ERA5再分析资料,对攀枝花降水特征及成因进行分析。... 为更好地认识青藏高原东南缘地形复杂区降水特征及其成因,利用位于青藏高原东南缘的攀枝花市2015—2020年72个国家、区域气象观测站资料和欧洲中心0.25°×0.25°分辨率的ERA5再分析资料,对攀枝花降水特征及成因进行分析。结果表明:(1)攀枝花降水具有地形作用突出、北多南少的特点,降水日数是造成降水空间分布差异的主要原因之一。(2)攀枝花夜雨特征显著,呈单峰型,降水峰值出现在03时(北京时),因攀枝花位于干热河谷区,日间湿度小、夜间湿度大,夜间较饱和的大气更容易凝结,触发降水,湿度的日变化是攀枝花易发生夜雨的原因之一。(3)攀枝花干湿季分明,6—10月为攀枝花湿季,11月至次年5月为攀枝花干季,6月和10月是干湿转换的过渡期。6月孟加拉湾西南季风爆发,攀枝花雨季开始,干季逐渐结束;10月干燥的高原南支西风气流加强,雨季趋于结束,干季开始。 展开更多
关键词 青藏高原 降水特征 南亚高压 西南季风 南支绕流
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春季青藏高原积雪年际变率的年代际转型对东亚夏季风影响的研究进展
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作者 张超 段安民 《大气科学》 CSCD 北大核心 2024年第1期321-332,共12页
冬春青藏高原积雪异常是东亚夏季风的重要预测因子之一。本文系统回顾了近20年关于青藏高原积雪年际变率的年代际转型影响东亚夏季风的相关研究,主要结论如下:(1)20世纪90年代初春季青藏高原积雪的年际变率从东西偶极型转变为全区一致型... 冬春青藏高原积雪异常是东亚夏季风的重要预测因子之一。本文系统回顾了近20年关于青藏高原积雪年际变率的年代际转型影响东亚夏季风的相关研究,主要结论如下:(1)20世纪90年代初春季青藏高原积雪的年际变率从东西偶极型转变为全区一致型,这主要受北太平洋、热带大西洋海温异常变化的影响,也与南极涛动、北极涛动的变化密切相关;(2)春季青藏高原积雪年际变率的年代际转型可通过影响东亚高层的副热带西风急流和低层的水汽输送,进而影响东亚夏季风降水格局变化;(3)青藏高原积雪异常可通过“高原大气河”的机制影响梅雨雨带;(4)大西洋年代际振荡可调节春季青藏高原积雪与梅雨降水关系的年代际变化,当大西洋年代际振荡为正(负)位相时,春季青藏高原积雪与梅雨的关系加强(减弱)。最后,本文对青藏高原积雪异常影响东亚季风变化的关键科学问题进行了讨论与展望。 展开更多
关键词 青藏高原 积雪 东亚夏季风 降水
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Paleoclimate and Paleoenvironment of Gonghe Basin, Qinghai-Tibet Plateau, During the Lastdeglacial: Weathering, Erosion and Vegetation Cover Affect Clay Mineral Formation 被引量:6
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作者 SUN Qingfeng Christophe COLIN 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2014年第2期647-660,共14页
With the analysis of the sources and formation mechanism of the clay minerals in the sediment core from the Dalianhai lake in the Gonghe Basin,northeastern Tibet-Qinghai Plateau,clay mineral composition proxies,grain-... With the analysis of the sources and formation mechanism of the clay minerals in the sediment core from the Dalianhai lake in the Gonghe Basin,northeastern Tibet-Qinghai Plateau,clay mineral composition proxies,grain-size and carbonate contents have been employed for high-resolution study in order to reconstruct East Asian Summer Monsoon (EASM) over the northeastern Tibet-Qinghai Plateau during the lastdeglacial.The study also extended to establish a relationship between vegetation cover changes and erosion during the last 14.5 ka with pollen record and clay mineral proxies.Smectite/kaolinite and smectite/(illite+chlorite) ratios allow us to assess hydrolysis conditions in lowlands and/or physical erosion process in highlands of the Gonghe Basin.Before 12.9 Cal ka BP,both mineralogical ratios show low values indicative of strong physical erosion in the basin with a dominant cold and dry phase.After 12.9 Cal ka BP,an increase in both mineralogical ratios indicates enhanced chemical weathering in the basin associated with a warm and humid climate.The beginning of Holocene is characterized by high smectite/(illite+chlorite) and smectite/kaolinite ratios that is synchronous as with deposition of many peat laminae,implying the best warm and humid conditions specifically between 8.0 to 5.5 Cal ka BP.The time interval after 5.0 Cai ka BP is characterized by a return to high physical erosion and low chemical weathering with dry climate conditions in the basin.Comparing variations of clay mineral assemblages with previous pollen results,we observe a rapid response in terms of chemical weathering and physical erosion intensity to a modification of the vegetation cover in the basin. 展开更多
关键词 clay minerals vegetation Gonghe Basin Tibet-Qinghai plateau Asian monsoon HOLOCENE
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Tibet,the Himalaya,Asian monsoons and biodiversity-In what ways are they related? 被引量:33
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作者 Robert A. Spicer 《Plant Diversity》 SCIE CAS CSCD 北大核心 2017年第5期233-244,共12页
Prevailing dogma asserts that the uplift of Tibet, the onset of the Asian monsoon system and high biodiversity in southern Asia are linked, and that all occurred after 23 million years ago in the Neogene.Here, spannin... Prevailing dogma asserts that the uplift of Tibet, the onset of the Asian monsoon system and high biodiversity in southern Asia are linked, and that all occurred after 23 million years ago in the Neogene.Here, spanning the last 60 million years of Earth history, the geological, climatological and palaeontological evidence for this linkage is reviewed. The principal conclusions are that: 1) A proto-Tibetan highland existed well before the Neogene and that an Andean type topography with surface elevations of at least 4.5 km existed at the start of the Eocene, before final closure of the Tethys Ocean that separated India from Eurasia. 2) The Himalaya were formed not at the start of the India-Eurasia collision, but after much of Tibet had achieved its present elevation. The Himalaya built against a pre-existing proto-Tibetan highland and only projected above the average height of the plateau after approximately 15 Ma. 3)Monsoon climates have existed across southern Asia for the whole of the Cenozoic, and probably for a lot longer, but that they were of the kind generated by seasonal migrations of the Inter-tropical Convergence Zone. 4) The projection of the High Himalaya above the Tibetan Plateau at about 15 Ma coincides with the development of the modern South Asia Monsoon. 5) The East Asia monsoon became established in its present form about the same time as a consequence of topographic changes in northern Tibet and elsewhere in Asia, the loss of moisture sources in the Asian interior and the development of a strong winter Siberian high as global temperatures declined. 6) New radiometric dates of palaeontological finds point to southern Asia's high biodiversity originating in the Paleogene, not the Neogene. 展开更多
关键词 Tibetan plateau HIMALAYA Uplift history monsoonS BIODIVERSITY Molecular phylogeny
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A multi-location joint field observation of the stratosphere and troposphere over the Tibetan Plateau 被引量:1
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作者 JinQiang Zhang Yi Liu +11 位作者 HongBin Chen ZhaoNan Cai ZhiXuan Bai LingKun Ran Tao Luo Jing Yang YiNan Wang YueJian Xuan YinBo Huang XiaoQing Wu JianChun Bian DaRen Lu 《Earth and Planetary Physics》 CSCD 2019年第2期87-92,共6页
The unique geographical location and high altitude of the Tibetan Plateau can greatly influence regional weather and climate.In particular, the Asian summer monsoon(ASM) anticyclone circulation system over the Tibetan... The unique geographical location and high altitude of the Tibetan Plateau can greatly influence regional weather and climate.In particular, the Asian summer monsoon(ASM) anticyclone circulation system over the Tibetan Plateau is recognized to be a significant transport pathway for water vapor and pollutants to enter the stratosphere. To improve understanding of these physical processes, a multi-location joint atmospheric experiment was performed over the Tibetan Plateau from late July to August in 2018, funded by the fiveyear(2018–2022) STEAM(stratosphere and troposphere exchange experiment during ASM) project, during which multiple platforms/instruments—including long-duration stratospheric balloons, dropsondes, unmanned aerial vehicles, special sounding systems, and ground-based and satellite-borne instruments—will be deployed. These complementary methods of data acquisition are expected to provide comprehensive atmospheric parameters(aerosol, ozone, water vapor, CO_2, CH_4, CO, temperature, pressure,turbulence, radiation, lightning and wind); the richness of this approach is expected to advance our comprehension of key mechanisms associated with thermal, dynamical, radiative, and chemical transports over the Tibetan Plateau during ASM activity. 展开更多
关键词 TIBETAN plateau Asian summer monsoon STRATOSPHERE and troposphere exchange
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