An analysis of anomalous weather and climate around the M _S=6.2 earthquake of Zhangbei region     

Qing-Sen Li  Yu-Mei Jin  Zhi-Cheng Miao  Wen-Zhong Jia  Gui-Cai Jiang 《地震学报(英文版)》1998,11(6):729-736

Through analysis we found that some mesoscale anomalous regions (10¹–10² km) of meteorological parameters such as the special drought areas, unusual warm areas, the largest snowfall center, low pressure area together with the epicenter area of M _S=6.2 Zhangbei earthquake on January 10, 1998 are located at the same area, i.e. there appears the “Five areas corresponding” phenomenon. Meanwhile, three times of low pressure evolution are generated and develop in the earthquake area in five days after the occurrence of the earthquake. The abnormal variation of the lower limit of frozen soil layer shows indirectly that unusual warm in earthquake areas are related to the upward thermal conduction from the deeper layer of earth surface.  相似文献   

研究季风区历史时期湖泊环境演化的意义   总被引：11，自引：3，他引：8  

王苏民  薛滨  张振克 《湖泊科学》1998,10(2):1-4

本文首先讨论了历史时期季风区湖泊环境演化研究在古全球变化研究中的地位及其意义,着重强调人与自然相互作用研究以及进行定量研究是该领域的关键所在。综合中国近年来在湖泊沉积与古全球变化研究中取得的成果,提出在该领域研究的一些新的认识与亟待解决的问题。  相似文献   

Impact of Boundary-Layer Parameterisation Schemes on the Prediction of the Asian Summer Monsoon     

Swati Basu  Z. N. Begum  E. N> Rajagopal 《Boundary-Layer Meteorology》1998,86(3):469-485

The impact of two boundary-layer parameterisation schemes on the prediction of Indian monsoon systems by a global spectral model has been investigated. The turbulent kinetic energy closure scheme shows a positive impact on the prediction of some important synoptic features, including the genesis of monsoon lows, the tracking of monsoon depressions, and precipitation.  相似文献   

Relationships between rainy days,mean daily intensity and seasonal rainfall in normal,flood and drought years over india     

C. V. Singh 《大气科学进展》1998,15(3):424-432

There are limitations in using the seasonal rainfall total in studies of Monsoon rainfall climatology. A correlation analysis of the individual station seasonal rainfall with all India seasonal mean rainfall has been made. After taking the significance test (strictly up to 5% level) the stations which are significantly correlated have been considered in this study in normal, flood and drought years respectively. Analysis of seasonal rainfall data of 50 stations spread over a period of 41 years suggests that a linear relationship fits better than the logarithmic relationship when seasonal rain-fall versus number of rainy days is studied. The linear relationship is also found to be better in the case of seasonal rainfall versus mean daily intensity.  相似文献   

PRELIMINARY ANALYSES OF THE ACTIVITIES OF SOUTH CHINA SEA SUMMER MONSOON IN 1998   总被引：1，自引：0，他引：1  

梁建茵  吴尚森 《热带气象学报(英文版)》2000,6(2):113-122

The NCEP reanalyzed data, OLR and SST observations are used to study the onset time and the multi-time scales features of the South China Sea (SCS) summer monsoon in 1998 and its interaction with the sea surface temperature and the effect on the precipitation in Guangdong province. It is found that the 1998 SCS summer monsoon set in on May 17 (in the fourth pentad of the month). The year witnesses a weak monsoon with the OLR oscillating at cycles of about 1 month and the Southwest Monsoon of about 1/2 month. The mon-soon over the Bay of Bengal and the cross-equatorial current near 105°are two driving forces for low-frequency variations of the SCS monsoon. The weak activity in the year was resulted from positive anomalies of SST in the equatorial eastern Pacific in early spring and subsequent formation of positive anomalies of SST in the SCS through the Arabian Sea.  相似文献   

1998年中国特大洪涝时期的环流特征   总被引：14，自引：3，他引：11  

林学椿  张素琴 《地球物理学报》2000,43(5):607-615

研究了 1 998年我国特大洪涝的环流特征 ,长江流域洪涝年全国有两种降水分布型 :即长江流域大水全国降水偏多型及长江流域大水其南北降水偏少型 .进而 ,研究了这两类分布型的环流特征 ,并指出北半球 50 0hPa位势高度场有着显著的差异 .鄂霍茨克海高压的建立是长江流域多雨的重要条件 ,南海高压的强弱在全国降水分布型中起着重要的作用  相似文献   

吉林晚石炭世威宁期石头口门裂陷槽的发现及地质意义     

郑春子  王光奇 《地质论评》1999,45(6):632-639

吉林晚石炭世要期石头口门裂陷槽位于长春东５０ｋｍ。该裂陷槽以海底火山沉积－－硅质岩沉积为主。早期以含锰结核的碎屑岩和泥岩、硅质岩为主,并有少量的凝灰碉和玄武岩;中期以海底火山喷发的高钠质细碧岩、角地为主,并伴有规模不大的蛇纹岩;晚期以硅质岩、长石杂砂岩、泥岩、生物碎屑灰岩为主,在生物碎屑灰岩中首次发现Ｆｕｓｕｌｉｎａ ｌａｎｃｅｏｌａｔａ Ｆ．ｓｐ．、Ｐｓｅｕｄｏｓｔａｆｆｅｌｌａ ｋｈｏｔｕｎｅ  相似文献   

Diagnostic study on seasonality and interannual variability of wind field   总被引：9，自引：0，他引：9  

Xue Feng  Zeng Qingcun 《大气科学进展》1999,16(4):537-543

l.Intr0ductionThoughseasonalvariationoftheatmosphericgeneralcirculationismainlycausedbythatofthesolarradiation,itsdistributionsareinhomogeneousovertheglobe,forinstance,itismoresignificantinmonsoonregionthaninanyotherregions.Inatraditionalsense,mon-soonsummarisesalldrasticseasonalvariationsinthetropicsandsubtropics(e.g.,IndiaandEastAsia).Besidestheclassicmonsoonregions,thereexistsomeotherregionsovertheglobe,wheretheseasonalvariationisclearorevendrastic.Inordertodescribequantitativelysea-sonal…  相似文献   

Precise dating of the Dansgaard-Oeschger event 4 and its sub-cycles: Evidence from a stalagmite from Xianyun Cave in Longyan City,Fujian Province     

Che Yin-Ping  Xiao Hai-Yan  Jiang Xiu-Yang  Cai Bing-Gui 《古地理学报》1999,22(2):377-384

The Dansgaard-Oeschger event 4(DO4 event) is a significant warming event that occurred in the late Marine Isotope Stage 3. At present,there are different understandings about the detailed characteristics and internal structures of the DO4 event. Based on 6 precisely-dated ²³⁰Th ages and 188 oxygen isotope data of a stalagmite(No.XYⅢ-28)from the Xianyun Cave,Fujian Province,we present δ¹⁸O time series with an average resolution of 7 yr from 29.13 to 27.94 kyr B.P. Our new stalagmites δ¹⁸O records uncover the detailed processes of the DO4 event. The onset and end time of the DO4 event recorded by the stalagmite δ¹⁸O is 28.83±0.06 and 28.46±0.06 kyr B.P.,respectively, and the duration is 0.37±0.06 kyr. Differential with abrupt change of NGRIP ice core δ¹⁸O record at the onset of DO4 based on the GICC05 layer count time scale,the Xianyun Cave δ¹⁸O shows a relatively slow change. The Xianyun stalagmite δ¹⁸O values negatively shift by 0.4‰ within 145±60 yr,which indicates that the Xianyun Cave was likely affected by the ocean-atmosphere coupling of the tropical. In addition,the Xianyun stalagmite δ¹⁸O reveals a series of sub-million-scale summer monsoon enhancement events in and around the DO4 event,corresponding to the NGRIP ice core δ¹⁸O record and the Arabian Sea basin record. Our results suggest that the East Asian summer monsoon is related to the north-high latitude temperature and the ITCZ position changes on the sub-millennium-scale event.  相似文献   

Late quaternary monsoon patterns on the Loess Plateau of China     

Li Jijun And  Feng Zhaodon  Tang Lingyu 《地球表面变化过程与地形》1988,13(2):125-135

China's Loess Plateau was formed under special conditions. The tectonic movement, topographical characteristics, and monsoon patterns combined to create a favourable environment for the accumulation of thick loessic deposits. The Loess Plateau itself is part of the ‘Monsoon Triangle’ of China, a region very susceptible to climatic changes. Throughout the Upper Pleistocene the palaeoenvironment on the Loess Plateau alternated from steppe, to deciduous forest and coniferous forest, in response to shifts in the atmospheric circulation. Three monsoon patterns appear to be indicated: (1) a full glacial monsoon pattern (18000–15000 yr BP) which induced a cold and dry climate favouring loess accumulation in steppe conditions; (2) an interglacial monsoon pattern (last interglacial and Holocene) in which a warm humid climate prevailed with deciduous forests, leaving palaeosols interbedded within the loess sequence; and (3) a transitional or interstadial monsoon pattern (50 000–23 000 yr BP) in which the climate was cold and humid in the Loess Plateau, encouraging the development of coniferous forest.  相似文献