The Mutual Feedback Of The Tibetan Plateau And The India Ocean And Their Influences On Temperature And Precipitation In China

The Qinghai-Tibet Plateau and the Indian Ocean are both located in the southwest of China.The Qinghai-Tibet Plateau is the highest plateau in the world,and its dynamic and thermal effects all have an important impact on China's climate.The Indian Ocean is the birthplace of India's monsoon and the main source of water vapor.Studying the heat conditions and coupling relationship between the plateau and the Indian Ocean is of great significance for a comprehensive understanding of the weather phenomena in China.This paper uses the ERA-interim temperature data of the Tibetan Plateau and the Indian Ocean in 1981-2010(30 years),and the Japanese Meteorological Center reanalysis data of 200hPa,500hPa,850hPa,925hPa for monthly mean geopotential height,vertical velocity,zonal wind speed(U component)and meridional wind speed(V component),water vapor flux divergence,and surface pressure data.the temporal and spatial characteristics of the temperature difference over the Tibetan Plateau and over the Indian Ocean and the interaction between them were analyzed.The results show that the temperature difference over the Qinghai-Tibet Plateau is positive in most regions of the winter,with high areas in the east,and a small negative area located in the middle of the plateau and on the western and southern borders.Overall,the Qinghai-Tibet Plateau provides heating to the atmosphere;In the summer both the main body of the Tibetan Plateau and the area north of the plateau are positive,and only the southeastern region has a negative area,it means that the surface of the plateau gives heat to the atmosphere in summer.The anomalous values of the ground-air temperature difference in the plateau were consistent in EOF1 in January,the plateau body and the northern plateau had an anti-phase change in EOF2.In July,the EOF1 has anti-phase phase in the eastern and western parts of the plateau changed,EOF2 consistent.The temperature difference between the sea surface and air in Indian Ocean is positive in January,and the ocean supplies heat to the atmosphere.In July,the monthlyaveragetemperature difference in Indian Ocean is positive,except for the western part of the Arabian Sea and the west of the Bay of Bengal.The EOF1 spatial distribution shows the zonal distribution of "-","+" and "-" in January,while EOF2 is opposite to EOF1.In July,the first modal spatial distribution has positive and negative ribbon antiphase distribution from northeast to southwest.The second modal region is characterized by a positive temperature difference.When the temperature difference over the Tibetan Plateau increased during the first modal month of January,The temperature difference between the Indian Ocean and the north of the equator will decrease,and the temperature difference between the Indian Ocean and the sea south of the equator will increase.When the EOF2 increases,the temperature difference over the Indian Ocean region in the southeast of the equator will decrease.It will be increase around 10°N and 20°S ocean.In July,the temperature difference over the Indian Ocean and decreased when the EO1 increased;when the EOF2 increased,the temperature difference in the southeastern Indian Ocean increased and the temperature difference in the west decreased.The strengthen of EOF 1 in the Indian Ocean in January will reduce the temperature difference between the Qinghai-Tibet Plateau and the strengthening of EOF2 will reduce the difference in temperature between the ground and the air.In July,the strengthening of EOF1 in the Indian Ocean resulted in an increase in the northern parts of the plateau and a decrease in the western part of the plateau;and the effect of EOF2 on the plateau was not significant.Both the plateau and the Indian Ocean have an impact on the temperature and precipitation in China and are independent of each other.In January,the plateau mainly affects the temperature in the Sichuan basin,the south of the Yangtze River basin and the Hetao area,and precipitation in the Sichuan basin and North China to East China;in July,it mainly affects the temperature in the first and second cascades,and precipitation in the Sichuan Basin,Northeast China,Huanghuai area,and the Yangtze River.In January,the Indian Ocean mainly affected the temperature in North China and Northeast China,and the precipitation in the northeast to southwestern strip region;in July,it affected the temperature of Xinjiang region,central and eastern Inner Mongolia,the Sichuan Basin,and the lower reaches of the Yangtze River,and precipitation in the northeastern Inner Mongolia to the Sichuan Basin.