The Spatial And Temporal Distribution Of Abrupt Change And Trend Of Surface Temperature In Asia In Nearly Five Decades

Based on the air temperature datasets from2467observation stations in China and global monthly air temperature from National Climate Data Center (NCDC), the datasets in Asia are interpolated and rized by inverse distance weighting method. The sensitivity experiment of observation density is conducted onto temperature abrupt change. The results show that at least33observation stations are needed for the analysis request for China. Therefore, only132stations are required for the analysis of the temperature abrupt change for Asia. A cross check is imposed onto the interpolated data in Asia. There are small deviations between the estimated value and real value, which indicates the estimated value can be applied to the analysis of air temperature trend and abrupt change in Asia.Using the rasterized data and reanalysis data from National Centers for Environmental Prediction-National Center for Atmospheric Research (NCEP/NCAR), the abrupt change of temperature during1961-2011over China and East Asia was analyzed by showing its spatial and temporal distribution. Finally, the possible factors responsible for the abrupt change regime of temperature over East Asia were discussed. The main conclusions are listed following:(1) The abrupt change mode of the annual mean temperature over China is well correlated with the latitude. The abrupt warming happened earlier both poleward and equator ward of35(?). Meanwhile, the abrupt change advanced from coast to inland. The spatial and temporal distribution of the abrupt change of the maximum temperature was similar to that of the mean temperature, while the abrupt change of the minimum temperature was ahead. The abrupt change of the temperature change over Tibetan Plateau was always later than that of most parts of China.(2) The abrupt change mode of the seasonal mean temperature over China shows obvious seasonal diversity. Differences are most evident between winter and summer. In winter, the air temperature advances from north to south. The regional of latest abrupt change takes place in the east of the plateau, and the time for abrupt change advances from coast to inland. In contrast, for summer China is divided into southeast part and northwest part due to the abrupt time. The boundary for the two parts is along the400mm isohyets, as well as the boundary between the monsoon region and non-monsoon region. To the southeast of the boundary, the abrupt occurs in1970s, while it occurs in1990s to the west. For Tibet Plateau, the abrupt happens later than other regions in China for both winter and summer, while in spring it is earlier than most China’s regions except Northeast and Southwest China Region.(3) The boundary for the abrupt time of the annual mean temperature over Asia between1980s and1990s divides the whole Asia into two parts:northeast part and southwest part. The zonal mean latest abrupt is located in30-40(?), and the abrupt happens earlier both pole ward and equator ward. The climatological difference of the abrupt change shows that the warming amplitude increases from south to north and from coast to inland.(4) The abrupt time of the seasonal mean temperature over Asia is similar to that of annual mean, which has a latest abrupt latitude zone. From this latitude zone, the abrupt happens earlier towards higher and lower latitudes. However, the latest latitude changes from season to season. The latest latitude moves northward when warming, while southward when cooling. The characteristic for the zonal advance is less obvious than that for the meridional advance. However, the earliest and latest meridional zones are both located in Tibet Plateau. In detail, the two earliest abrupt meridional zones for summer mean temperature are close the east and west sides of Tibet Plateau.Finally, the main factors affecting the abrupt change of temperature over East Asia were discussed, including:in the decadal scale, AO affected Asian mainland and high latitudes temperatures significantly in winter; tropical sea surface temperature anomalies abrupt have an impact on the Asian summer temperatures by affecting the Asian summer monsoon; the effect of Tibetan Plateau on the abrupt change of temperature is evident in that the meridional mean abrupt change time varies along longitude, especially for the double-valley structure in summer. It is deduced that the dynamical separation of Tibetan Plateau on the monsoon may play a role.