Dingrui CAO

Cao Dingrui obtained her bachelor degree from the Northwest Normal University in environmental Engineering in 2016 and master degree from the Zhejiang University in atmospheric sciences in 2019, respectively. She is studying for doctor degree in the Chinese University of Hong Kong from 2019 to present. The research work is the influence of El Niño diversity on extreme precipitation over East Asia.

Research Interests:

• El Niño diversity
• Large-scale extreme rainfall
• East Asia Monsoon

Recent Research Projects:

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The current work is focused on “Impacts of decaying EI Niño on East Asian (EA) extreme precipitation and its diversity”. The spatial distribution of extremes shows the opposite spatial patterns during Eastern-Pacific (EP) and central-Pacific (CP) El Niño. More intense spring extremes over the southern China (SC) are observed during EP El Niño, while the situation is revise during CP El Niño.

In decay summer, intense extreme events over the south of Yangtze River (SYR) during EP El Niño and less extremes over the Mei-Yu rain band in China, Baiu in Japan, Changma in South Korea (MBC) are observed. During CP El Niño, weaker (stronger) extremes over SYR (MBC) are found. The displacement of Western Pacific subtropical high (WPSH) is the main reason for the opposite distribution of extremes during EP and CP El Niño. In decay spring, the anticyclonic anomaly is found over WNP basin during EP El Niño. Southwest winds contribute to form the moisture source of extremes over SC (figure 1a). During CP El Niño, the anticyclonic anomaly extends westward to the east Bay of Bengal (EBOB), which impedes the moisture transported from the EBOB (figure 1b). In decay summer (Figure 1c and 1d), when EP (CP) El Niño occurs, the westerly jet (WJ) tends to be displaced southward (northward) in relation to the positioning of WPSH, contributing to stronger vertically integrated moisture flux convergence over SYR (MBC), while there is moisture flux divergence over MBC (SYR).

The different flow patterns associated with El Niño diversity appear to be forced by different SST warming signals in either tropical Indian Ocean or Maritime Continent regions, which can induce anomalous regional atmospheric circulation that affects the behaviors of WPSH and WJ.

“Two types of El Niño and their impacts on extremes over EA in CMIP6 models” is another ongoing work.

Figure 1. Mechanisms leading to extreme precipitation changes over SC in March-April-May (MAM), and SYR and MBC in June-July-August (JJA) during (a, c) EP and (b, d) CP EI Niño.