Contrasting Impacts of Two-type El Nino over the Western North Pacific during Boreal Autumn

This work contrasts the climatic impacts of so-called warm-pool (WP) and cold-tongue (CT) El Nino on the atmospheric circulation over the western North Pacific (WNP). It is found that the anomalous atmospheric circulation over the WNP is nearly opposite in response to these two types of El Nino events in developing autumn. A weak anomalous anticyclone appears o'er the WNP during CT El Nino, whereas a weak anomalous cyclone emerges in the same region during WP El Nino. These nearly opposite autumn responses of atmospheric circulation have a significant impact on East Asian climate, aid southern China autumn rainfall in particular, although this contrast tends to diminish as El Nino events enter their mature phase.