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Characteristics of surface sensible heat flux over the Qinghai-Tibetan Plateau and its response to climate change


Journal

Plateau Meteorology

Authors

Xie Jin, Yu Ye, Liu Chuan, Ge Jun

Year

2018

Volume

37

Issue

1

Pages

28-42

Corresponding Author

Yu, Y

Request Full Text

yyu@lzb.ac.cn

Keywords

Qinghai-Tibetan Plateau; sensible heat flux; M-K test; EOF analysis; Pearson correlation

Abstract

Using the conventional meteorological observation data of the Qinghai-Tibetan Plateau (QTP) offered by the China Meteorological Administration (CMA),the average daily sensible heat flux from 1981 to 2014 was calculated on the basis of 85 stations which have continuously better data and the CHEN-WENG heat exchange parameterized scheme. The characteristics of seasonal average and annual average sensible heat flux and the connections between them and climate factors which include surface temperature,air temperature at 1.5 m,wind speed,precipitation and sunshine duration were analyzed by using the methods of Mann-Kendall test,empirical orthogonal function (EOF),and Pearson correlation. The results showed that both seasonal average and annual average sensible heat flux had risen after falling for more than 20 years since 1981 and the time of change happened earlier in winter and spring than in summer and autumn. The decline of sensible heat flux between 1981 and 2003 was mainly caused by the decrease of land-air temperature difference and the average wind speed, while the raise between 2004 and 2014 was mostly due to the significantly increase of land-air temperature difference, and not all stations had the same pace in decrease or increase. The stations which increased mostly locate in Qinghai province. In addition,the correlations between the sensible heat flux and climate factors are obviously temporal and spatial different. Almost the whole stations are significantly influenced by the surface temperature with positive correlation with sensible heat flux,while other climate factors are probably tend to have a better correlation with sensible heat flux in the growing season than in the whole year,especially in summer when the sensible heat flux mostly has a negative correlation with the precipitation and a positive correlation with wind speed,air temperature at 1.5 m and sunshine duration.