Anomalous Features of Water Vapor Transport during Severe Summer and Early Fall Droughts in Southwest China

作者：Liu, Zhenchen; Lu, Guihua; He, Hai^*; Wu, Zhiyong; He, Jian

来源：Water (Switzerland), 2017, 9(4): 244.

DOI：10.3390/w9040244

• water vapor transport
• standardized anomalies
• drought processes
• Southwest China

Water vapor transport (WVT) is an important element in drought development. In this study, we examined the geographical and vertical anomalies of WVT during severe summer and early fall drought processes and their occurrence, persistence and recovery phases in Southwest China (SWC) by using the method of standardized anomalies (SA) and composite analysis. The SA-based indices of WVT were built up to quantify composited anomalous WVT channels objectively. Essentially, we further explored the synchronous and lagged correlations between drought processes and these channels. Key points and limitations include: (1) Two drought-related WVT channels were geographically identified with composited SA below -0.2, based on the composite of severe drought processes. The Somali channel is characterized by zonally less-than-normal African-Asian continental WVT anomalies originating from Somalia, whereas the IndoChina-Peninsula channel represents meridionally less-than-normal WVT anomalies from the IndoChina-Peninsula; (2) Both geographical and vertical WVT anomalies were intensified and concentrated at the time of drought occurrence, and then weakened and became scattered at drought recovery; (3) Most drought-related WVT anomalies were distinguishable from those of wetter events; (4) The IndoChina-Peninsula channel performs better in correlations with these drought and wetter processes than the Somali channel. Therefore, dynamic and thermodynamic anomalies need to be investigated, which are important for exploring the drought mechanism.

• 出版日期2017-4
• 单位河海大学