Cross-tropopause transport over the Tibetan Plateau and its ambient regions during late summer/early fall 2004

Using new measurements from NASA's Aura Microwave Limb Sounder (MLS), this study reveals the close correspondence between the deep convections and the atmospheric constituents, including those from anthropogenic sources, near or above the tropopause over the Tibetan Plateau and the Asian monsoon regions in August and September 2004. Convective transport and mixing are detailed in MLS H2O, CO, O3, with the advantage of the new MLS cloud products (i.e., cloud induced radiances and ice water contents). Vigorous convective updrafts penetrating across the base of the overworld (~ 380 K potential temperature) were observed for the region considered. While deep clouds tent to disturb the water vapor field in the evening for their higher penetration, they are more contaminated by the industrial pollution in the morning. It is found that the Tibetan High and its diurnal variation may also play an important role in controlling the cross tropopause transport. GMAO meteorological fields and MODIS cloud data for the same period were examined to relate the dynamical and microphysical evolution of these deep clouds.