The quantitative comparison of contributions from vapour and temperature to midsummer precipitation in China under the influence of spring heat source over Tibet Plateau

Abstract

The thermal forcing of the Tibet Plateau (TP) causes circulation anomalies that may affect the East Asian monsoon. Hence, summer precipitation in China has a close relation to the previous heat source over TP. The saturation of the atmosphere is the precondition of precipitation, so variations of vapour and temperature adjust the generation of precipitation synergistically. The heating of TP exerts impacts on summer precipitation in China, essentially, through modulating vapour and temperature. The goal of this study is to identify whether the variations of temperature or vapour dominate in the end. Besides, according to the heating characteristics over TP, a more accurate area of spring (March–May) heat source is chosen to indicate the midsummer (July) precipitation in China. The configuration of contributions of temperature and vapour can be divided into two cases. One is that vapour and temperature both increase or decrease, so they play inverse roles. It is easy to find the dominant element in this circumstance. The other is that vapour and temperature have concurrent effects. In this case, their significances need to be further compared. The method based on the linkage of the precipitation and relative humidity is used to quantitatively compare the effects of temperature and vapour. The results are robust and can complement the qualitative analysis with circulations and temperature. In years that there is intense heating on west TP, the Yangtze River basin (YZRB) is controlled by more vapour transport from oceans. The downstream of the Yellow River basin (YLRB) is affected by the dry and cold northerly winds. Dominance analysis shows that vapour general plays a more important role in two major river basins. Maybe not exactly coincide with someone's envision, not all the places are dominated by the vapour. Around northeast China, temperature contributes little more than vapour.

Impacts of Tibetan Plateau sensible heat and El Niño–Southern Oscillation on precipitation over South China under the background of the PDO

“…Referring to previous studies (Lu et al, 2010;Tu and Lu, 2020;Hao and Lu, 2021), if the variable Z is affected by multiple factors such as X and Y at the same time, and the relationship between Z and the influencing factors X, Y, etc., is non-linear; it can be written in the general form of Z = Z(X, Y). To explore the relative importance of influencing factors, and to assess whether variable Z is more influenced by variable X or Y, multiple linear regression Z = AX + BY + ε can be used to fit their relationship, in which A = zZ/zX and B = zZ/zY expressed the mean the change rates of Z with X and Y, respectively.…”

The Ice-and-Snow Tourism in Harbin Met Its Waterloo: Analysis of the Causes of the Warm Winter with Reduced Snowfall in 2018/2019

“…In this study, an analysis tool is utilized to compare the effects of the warmerthan-normal air temperature and the anomalies in the water vapor supply. This tool has been used to investigate the severe droughts and floods that occurred in recent years in China [29][30][31], and has also been adopted to verify the causes of anomalous precipitation in the interannual variation in precipitation [32,33].…”

The 2014 severe drought over northeast China and its comparison with droughts over the southern regions: A perspective from synergic effects of water vapour and cold air

“…It is based on the physics of precipitation formation and has been used to investigate the droughts over the southern regions (Lu et al ., 2011; 2014). In addition to this method, an alternative tool, which uses statistical regression, has also been adopted to verify the conclusions obtained for the relative importance of water vapour and air temperature in the interannual variation of precipitation (Tu and Lu, 2020; Hao and Lu, 2021).…”