Characteristics of concurrent precipitation and wind speed extremes in China

Abstract

Abstract Compound precipitation and wind speed extremes can significantly impact ecosystems, socio-economies, and human health. The characteristics of precipitation or wind speed extremes have been extensively studied, however, concurrent precipitation and wind speed extremes have received very little attention to date. This study focused on the characteristics of concurrent precipitation and wind speed extremes from 1981 to 2018 in China based on daily precipitation and maximum wind speed observations. The results showed that concurrent precipitation and wind speed extremes were most likely to occur in southern China, especially in the southeast coastal areas (frequent tropical cyclones). The concurrent extremes showed a downward trend in 1981–2010 followed by an upward trend in 2011–2018. The reversal of the concurrent extremes around 2011 may be related to the increase in individual extreme precipitation and wind speed. We divided the concurrent extremes into four grades based on the magnitudes: mild, moderate, severe, and extreme. Concurrent extremes of all four grades all reversed around 2011; the mild and moderate events in particular showed significant increasing trends from 2011 to 2018. High percentages (more than 50%) of concurrent precipitation and wind extremes were found in summer months. We ranked the top 10 concurrent precipitation and wind speed extremes in 1981–2018 by magnitude to observe their spatial characteristics. We analyzed the mechanisms of the strongest concurrent event (top 1 on August 19, 1997) and the most recent concurrent event (top 2 on July 20, 2016) to conclude that the typhoon and strong convective weather systems can cause high-magnitude concurrent precipitation and wind speed extremes.