报告题目：The roles of different convective systems in the monsoonal overturning circulation
This study investigates the relative roles of different convective systems in the atmospheric overturning circulation of the South Asian summer monsoon (SASM). A cloud classification and tracking technique is used to decompose a convection-permitting SASM simulation into the clear sky, shallow convection, congestus, isolated deep convection, and mesoscale convective system (MCS) regimes. The statistical properties of simulated convective systems are compared with satellite observations and atmospheric reanalysis. Results show that the convection-permitting simulation realistically captured the spatiotemporal distributions and rainfall characteristics of the SASM convective systems. An isentropic analysis technique is then adopted to examine the relative contributions of different convective systems to the total monsoonal overturning circulation. Analyses indicate that MCSs play a crucial role in the total vertical mass, water, and energy transports during the SASM. In addition, the per event vertical transports associated with MCSs is around 70-100 times stronger than that associate with isolated deep convection. The vertical mass and energy transports associated with MCSs and isolated deep convection peaking in the upper troposphere, which are mostly contributed by updrafts over stratiform region, and also partially contributed by deep convective updrafts. Below the melting level, MCSs and congestus show larger contributions to the total vertical mass, water, and energy transports than the other convective systems. The vertical transports produced by shallow convection are mostly confined below 2 km. The subseasonal variability of vertical mass, water, and energy transports associated with different convective systems are further studied. The overturningsassociated with MCSs show stronger subseasonal variability than that associated with the other convective systems.
会议 ID：811 732 990