Prominent features of large-scale atmospheric circulation during spring droughts over northeast Asia

作者：Park Jong Seo; Jhun Jong Ghap^*; Kwon MinHo

来源：International Journal of Climatology, 2010, 30(8): 1206-1214.

DOI：10.1002/joc.1948

• spring drought
• East Asian jet index
• sea surface temperature
• large-scale circulation
• Western North Pacific subtropical high

We analysed anomalous large-scale atmospheric circulations during springtime droughts that occurred over northeast Asia between 1960 and 2005. The Palmer drought severity index was used in order to define drought years. Anomalies with regard to the intensity of the Western North Pacific subtropical high, the position of the East Asian jet (EAJ), and the sea surface temperatures (SSTs) in the Pacific Ocean during drought years are apparent. In drought years, the anomalous circulation over northeast Asia weakens the northward flow from the Western Pacific. In addition, the position of the EAJ maximum core is shifted southward, and this assertion is supported by EAJ-index analysis. Therefore, the rainfall band is moved southward, and the associated precipitation is suppressed over Korea, Japan, and Southeast China during spring droughts. The warm SST anomalies and negative outgoing longwave radiation anomalies, which consist of a north south dipole pattern between the Philippines and the northeast Asian region, support these dry conditions through Hadley circulation. The anomalous warm SSTs in the Western Pacific seem to play an important role in the atmospheric circulation associated with northeast Asian droughts.

• 出版日期2010-6-30