Interannual variations of spring drought-prone conditions over three subregions of East Asia and associated large-scale

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ORIGINAL PAPER

Interannual variations of spring drought-prone conditions over three subregions of East Asia and associated large-scale circulations Chang-Kyun Park 1 & Chang-Hoi Ho 1

&

Doo-Sun R. Park 2 & Tae-Won Park 3 & Jinwon Kim 4

Received: 13 April 2020 / Accepted: 26 August 2020 # Springer-Verlag GmbH Austria, part of Springer Nature 2020

Abstract For proactive prevention of water shortage problems, it is important to understand the spatiotemporal variabilities of droughts and their development mechanisms. This study identified an interannual variation of spring drought-prone condition in each region of East Asia (EA)—northern, mid, and southern EA—for the period 1979–2015 by using the standardized precipitation evapotranspiration index (SPEI) and a hierarchical clustering analysis. According to our analyses, spring drought-prone condition in the northern EA region mainly depends on local surface heating and precipitation deficit due to adiabatic compression by a highpressure anomaly over the region during the preceding winter to spring. The high-pressure anomaly was driven by an upper-level wave train propagating from the Europe related to a positive phase of the Arctic Oscillation. For drought-prone conditions in the mid and the southern EA regions, the local precipitation deficit caused by the negative moisture advection/convergence therein acts as a primary factor. During the preceding winter, the negative moisture advection/convergence anomalies both in mid and southern EA regions were induced by anomalous low-level cyclonic circulations over the western North Pacific related to the La Niña. In spring, however, the moisture condition in the southern EA region was affected by persistent La Niña while that in the mid-EA region was by the negative phase of North Pacific Oscillation. This gap makes the main location of the negative moisture advection/convergence anomalies just slightly different, but considerably alter the region exposed to the drought-prone condition. Keywords Spring drought . East Asia . SPEI . Arctic Oscillation . El-Niño Southern Oscillation . North Pacific Oscillation

1 Introduction Droughts are recurring natural disasters in East Asia (EA) (Byun et al. 2008; Lee et al. 2012; Zhang and Zhou 2015). For example, consecutive reductions in food production due to severe droughts Electronic supplementary material The online version of this article (https://doi.org/10.1007/s00704-020-03371-5) contains supplementary material, which is available to authorized users. * Chang-Hoi Ho [email protected] 1

School of Earth and Environmental Sciences, Seoul National University, Seoul, Korea

2

Department of Earth Science Education, Kyungpook National University, Daegu, Korea

3

Department of Earth Science Education, Chonnam National University, Gwangju, Korea

4

National Institute of Meteorological Sciences, Korea Meteorological Administration, Jeju, Korea

significantly contributed to the collapse of the Tang and Ming dynasties in China (Wang et al. 2010; Zhang et al. 2014). Recent observati