[ACG34-P09] Impact of tropical convections on cold air outbreaks in East Asia
Keywords:winter monsoon, cold air outbreak, tropical convection, ENSO, MJO
CAOs are basically driven by internal synoptic conditions in the extratropics. However, their variations are potentially affected by the tropical atmosphere. The tropics exhibit large formation of deep convective clouds whose abundant condensational heating excites the large-scale disturbances that may remotely control the extratropical atmosphere and thus the CAOs.
Our presentation will show how the tropical convections influence the occurrence of CAOs in East Asia. In short, the connection between CAOs and the tropics is prominent in the intraseasonal scale  and interannual scale . In the intraseasonal scale, the CAOs are affected by the eastward-propagating Madden-Julian Oscillation (MJO). CAOs become particularly more active when the passage of MJO appears over the Maritime Continent. In the interannual scale, El Niño-Southern Oscillation plays a major role. The CAOs become less (more) active during El Niño (La Niña), respectively. A better understanding of tropical-extratropical interactions may improve the predictability of CAO events.
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