The Effects of the Thermal Anomalies over the Tibetan Plateau and Its Vicinities on Climate Variability in China

The evident effects of the thermal anomalies over the Tibetan Plateau (TP) and its vicinities are summarized and discussed in this paper. By the singular value decomposition (SVD) technique and numerical simulations of the effect of the snow depth anomaly over the TP, it is shown that the snow depth anomaly, especially in winter, is one of the factors innuencing precipitation in China, and the winter snow anomaly is more important than the spring one. The relations between the sensible heat anomaly over the TP and the intensity of the South China Sea summer monsoon (SCSSM) are studied, too, and two key areas of the sensible heat anomaly over the TP are found. The relationships between the South Asia High (SAH) and the precipitation in the years with typical droughts or floods in the mid to lower valleys of the Yangtze River (MLVYR) and North China are investigated in some detail. It is found that not only the intensity of the SAH over the TP, but also the 100-hPa height in a large area influences the precipitation in the above two regions. The effects of the SAH on the onsets of the tropical Asian summer monsoon (TASM) including the SCSSM and the tropical Indian summer monsoon (TISM) are studied as well. It is found that the onset times of both the SCSSM and the TISM are highly dependent upon the latitudinal position of the SAH center.

Diurnal Variation of Tropical Cyclone Rainfall in the Western North Pacific in 2008-2010

Diurnal variation of tropical cyclone （TC rainfall in the western North Pacific （WNP） is investi gated using the high-resolution Climate Prediction Ce~ ter＇s morphing technique （CMORPH） products obtaine from the National Oceanic and Atmospheric Administra tion （NOAA）. From January 2008 to October 2010, 7 TCs and 389 TC rainfall days were reported by the Joir Typhoon Warning Center＇s （JTWC） best-track record. Th TC rain rate was partitioned using the Objective Synopti Analysis Technique （OSAT） and interpolated into Local Standard Time （LST）. Harmonic analysis was applied t analyze the diurnal variation of the precipitation. Obviou diurnal cycles were seen in approximately 70% of the TC rainfall days. The harmonic amplitude and phase of the mean TC rainfall rate vary with TC intensity, life stage, season, and spatial distribution. On the basis of intensity, tropical de- pressions （TDs） exhibit the highest precipitation variation amplitude （PVA）, at approximately 30%, while super ty- phoons （STs） contain the lowest PVA, at less than 22%. On the basis of lifetime stage, the PVA in the decaying stage （more than 37%） is stronger than that in the devel oping （less than 20%） and sustaining （28%） stages. On the basis of location, the PVA of more than 35% （less than 18%） is the highest （lowest） over the high-latitude oceanic areas （the eastern ocean of the Philippine Islands）. In ad dition, a sub-diurnal cycle of TC rainfall occurs over the high-latitude oceans. On the basis of season, the diurnal variation is more pronounced during summer and winter, at approximately 30% and 32%, respectively, and is weaker in spring and autumn, at approximately 22% and 24%, respectively.