Tropical convective transport and the Walker circulation
We introduce a methodology to visualise rapid vertical and zonal tropical\ntransport pathways. Using prescribed sea-surface temperatures in\nfour monthly model integrations for 2005, we characterise preferred\ntransport routes from the troposphere to the stratosphere in a high\nresolution climate model. Most efficient transport is modelled over\nthe Maritime Continent (MC) in November and February, i.e., boreal\nwinter. In these months, the ascending branch of the Walker Circulation\nover the MC is formed in conjunction with strong deep convection,\nallowing fast transport into the stratosphere. In the model the upper\ntropospheric zonal winds associated with the Walker Circulation are\nalso greatest in these months in agreement with ERA-Interim reanalysis\ndata. We conclude that the Walker circulation plays an important\nrole in the seasonality of fast tropical transport from the lower\nand middle troposphere to the upper troposphere and so impacts at\nthe same time the potential supply of surface emissions to the tropical\ntropopause layer (TTL) and subsequently to the stratosphere.