Interdecadal Change in the Intensity of Interannual Variation of Spring Precipitation over Southern China and Possible Reasons

Abstract

The intensity of interannual variation of spring precipitation over southern China during 1979–2014 and possible reasons for it are investigated in this paper. There is a significant interdecadal change in the intensity of interannual variation of spring precipitation over southern China around 1995/96. The intensity of interannual variation of spring rainfall over South China is stronger during 1979–95 than that during 1996–2014. The possible reason may be the larger amplitude of the sea surface temperature anomaly (SSTA) in the western Pacific Ocean (WP) before 1995/96. The cooler (warmer) SSTA in WP may trigger an abnormal local anticyclone (cyclone) at lower levels. The anomalous southwesterly (northeasterly) flow at the northwestern flank of the WP anticyclone (cyclone) covers South China, transporting more (less) moisture to South China. Meanwhile, the anomalous winds converge (diverge) in South China at lower levels and diverge (converge) at upper levels, which causes the anomalous ascent (descent) to enhance (reduce) the precipitation over there. However, during 1996–2014, the intensity of interannual variation of spring rainfall over the middle and lower reaches of the Yangtze River valley becomes much stronger than that during 1979–95, which is related to the intensified interannual variation of the atmospheric circulation in the middle and high latitudes over Eurasia. The weak (strong) Siberian high and East Asian trough may reduce (enhance) the northerly wind from the middle and high latitudes. As a result, the middle and lower reaches of the Yangtze River valley are subjected to the anomalous southerly wind, favoring more (less) precipitation over there.

Interdecadal Variation of Early Spring Rainfall Over the Southeastern Edge of the Tibetan Plateau

“…2016; X. F. Wu and Mao 2016; Xu et al. 2019). In fact, the early spring rainfall over the SEETP tends to vary in‐phase with that over South China (Figures 2 and 3d).…”

Probability Models and Statistical Tests for Extreme Precipitation Based on Generalized Negative Binomial Distributions

“…The extreme precipitation volumes and intensities are relevant to various problems of climatology and hydrometeorology (see, for example, [44][45][46][47]). Traditionally, these phenomena are investigated for different geographical regions or countries [48,49]. In particular, the issue of determining threshold values, the excess of which leads to the extreme events, for example, in daily rainfalls or their intensities, is the key point of the study.…”

Interdecadal Variability of Summer Precipitation Efficiency in East Asia

“…It can also be defined as the ratio of precipitation rate to the vertical integral of condensation and deposition rates derived from the cloud microphysical budget [9,31,32]. e PE also serves as a crucial factor in the parameterization of cumulus convection [33][34][35][36].…”

“…With increasing water vapor in the lower troposphere, the intensity of moist convection lessens and mass exchange between the boundary layer and the middle troposphere decreases to balance the global hydrological cycle [32,33]. Xu et al [36] suggested that the interdecadal change in the intensity of spring rainfall variations over southern China can be attributed to the reduced amplitude of SSTAs in the West Pacific after 1996.…”

“…Summer precipitation anomalies in East Asia can lead to flood and drought disasters that impact nearly one-third of the world's population and cause great economic damage [35,36,41,42]. Although the importance of PE for the precipitation variability is widely known, previous studies have paid little attention to the spatiotemporal evolution of PE in East Asia and its relation to atmospheric dynamic and thermodynamic processes.…”