Characteristics and relationships between daily maximum boundary layer height and precipitation in the arid and semi-arid regions of East Asia
Caractéristiques et relations entre la hauteur maximale quotidienne de la couche limite et les précipitations dans les régions arides et semi-arides de l'Asie de l'Est
Guo, Yanling ; Zhang, Wenyu ; Mao, Lixin ; Wang, Kaiqiang
Water scarcity seriously affects the ecological balance and economic development in the arid and semi-arid regions of East Asia. The variability of precipitation is one of the important factors affecting water resources. In this paper, the spatio-temporal variation characteristics of the daily maximum boundary layer height (BLH) and precipitation (Prec) from 1900 to 2010 are analysed by using ERA-20C reanalysis data with mathematical statistical methods. On this basis, the relationship between the daily maximum height and precipitation was explored. Over all of the extreme arid and the western of arid regions, daily maximum BLH decreased when precipitation increased, while in eastern parts of the arid and the whole of semi-arid regions, daily maximum height increased when precipitation decreased. Over time, the annual changes of the height and precipitation basically showed the opposite trend. In the extreme arid and the arid areas, changes of daily maximum BLH and precipitation were relatively gentle. In the semi-arid region, the daily maximum height and precipitation experienced an abrupt climate change in 1962 and 1957, respectively. After 1962, the average daily maximum height increased by 122m, and after 1957, the average annual precipitation decreased by 52.19mm. Daily maximum BLH is basically negatively correlated with precipitation, with the strongest correlation in the semi-arid area and the weakest in the extreme arid area. The wetter the climate, the greater the influence of ?BLH on ?Prec. A decrease in boundary layer leads to an increase in water vapour content in the boundary layer, which is conducive to the formation of precipitation. Moreover, the greater the slope decrease of daily maximum height, the greater the precipitation.</p>
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