The Relationship between Indo-Pacific Convection Oscillation and Summer Surface Air Temperature in Southern Asia

Abstract

The relationship between Indo-Pacific convection oscillation (IPCO) and summer (June-August) surface air temperature in southern Asia (including India and Indochina) is investigated for the period of 1979−2013 using observational datasets and a theoretical linear baroclinic model. In the summers with the positive IPCO phase, when the convection over the western North Pacific (north Indian Ocean) is enhanced (suppressed), the Southeast Asian summer monsoon is enhanced and the southern Asia is cooler than usual, and vice versa. The “positive-negative-positive” air temperature advection anomalies by anomalous wind play an important role in the negative relationship between the IPCO and surface air temperature in southern Asia. It is also found that this negative correlation is greatly enhanced in El Niño-Southern Oscillation decay years.