Variation Features Of Summer High-temperature And Its Influence Process In China

Based on the China Meteorological Administration reorganization of the 195 stations daily maximum temperature, daily average air temperature data and NCEP\NCAR reanalysis data set, variation features of summertime high temperature and its causes are analyzed from 1960 to 2010 in China. Results showed that:(1) high-temperature days increased in China summer and autumn between 1960-2010, but not obvious in spring; summer high-temperature days significantly increase from the mid-2000s, high-temperature days obviously increase in northwestern region, in parts the Sichuan Basin, northern North China, Northeast China, Zhejiang Fujian coastal areas and southern coastal areas of Guangdong in China summer;(2) after SVD analysis, summer high-temperature days in Shanxi Province, the Loop region to Yunnan, the northeastern region and the Yangtze River and the average height of the Northern Hemisphere 500hPa low latitude field strength was significantly correlated with the same period and the previous from 1960 to 2010, The average fall of the Northern Hemisphere 500hPa height field strength of the polar vortex is negatively correlated; and the previous year, the polar vortex in winnter, eastern Europe and Asia, the intensity of the eastern trough is a negative correlation; with the same year in spring trough intensity of East Asia into negative;(3) there are four continuous high-temperature of the average height of 500hPa circulation field, the northwest ridge warm, warm continental high-pressure type, the Western Pacific subtropical high in the North and South in China;(4) northwest warm ridge, warm continental high-pressure high-temperature heating process of the corresponding type of SAH in eastern Tibet are high pressure, high-temperature conducive to the maintenance of northern China; North West Pacific subtropical high pressure type of process in South Asia is the western-based Tibetan high, is conducive to China in maintenance of the western high temperature; South West Pacific subtropical high-type SAH corresponding type of Iran belongs to the western pressure, which will help create high temperatures in summer in the south of the Yangtze River; subtropical westerly jet axis south, east jet center is conducive to the North China rising temperatures, jet axis south, west jet center, jet strength is weak, which are conducive to the occurrence of high summer temperatures in southern China, and maintained. Atmospheric heating field integral whole the results show that warm ridge northwest, continental type of warm high pressure high temperature process is mainly affected by the whole layer of the vertical temperature advection and adiabatic heating caused by the combined effect of temperature, vertical temperature advection whole floor can be interpreted as North and South West Pacific High temperature process heat to maintain a reason;(5) high-temperature days in summer changes associated with sea surface temperature certainly, the growth in the high-latitude North Pacific sea surface temperature will make Shanxi, Gansu, the Loop region to Yunnan, northeast region and the Yangtze River high-temperature days increased in China summer, while eastern equatorial Pacific sea surface temperature rise will make high-temperature days reduced in these areas. Numerical simulation results show that 500hPa height field; in the low latitude Pacific sea surface temperature increase of temperature of the subtropical high is the possible mechanism of intensity.