Different Evolutions of the Philippine Sea Anticyclone between the Eastern and Central Pacific El Nino: Possible Effects of Indian Ocean SST

作者：Yuan, Yuan; Yang, Song^*; Zhang, Zuqiang

来源：Journal of Climate, 2012, 25(22): 7867-7883.

DOI：10.1175/JCLI-D-12-00004.1

• WESTERN NORTH PACIFIC
• ASIAN SUMMER MONSOON
• SURFACE TEMPERATURE
• INTERDECADAL VARIABILITY
• ANOMALOUS ANTICYCLONE
• ENSO VARIABILITY
• DIPOLE MODE
• IMPACTS
• CLIMATE
• RAINFALL

The authors examine different evolution features of the low-level anticyclone over the tropical north-western Pacific between eastern Pacific (EP) El Nino events and central Pacific (CP) El Nino events. During EP El Nino, the low-level anticyclone shows an eastward movement from the northern Indian Ocean to the east of the Philippines. During CP El Nino, however, the anticyclone is mostly confined to the west of the Philippines. It is weaker, exhibits a shorter lifetime, and lacks eastward movement compared to the Philippine Sea anticyclone (PSAC) during EP El Nino. Investigation into the possible impact of Indian Ocean (IO) sea surface temperature (SST) on the evolution of the low-level anticyclone during EP and CP El Nino indicates that both SST and low-level atmospheric circulation over the IO are related more strongly with EP El Nino than with CP El Nino. The IO SST tends to exert a more prominent influence on PSAC during EP El Nino than during CP El Nino. During the developing summer and autumn of EP El Nino, the anomalous anticyclone over the northern Indian Ocean excited by positive IO dipole may contribute to an early development of the PSAC. During the winter and decaying spring, the anomalous anticyclone to the east of the Philippines instigated by the IO basin-wide warming mode also favors a larger persistence of the PSAC. During CP El Nino, however, IO SST shows a negligible impact on the evolution of the anticyclone.

• 出版日期2012-11
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