Tue. May 31, 2022 11:00 AM - 1:00 PM Online Poster Zoom Room (6) (Ch.06)

convener:Toru Terao(Faculty of Education, Kagawa University), convener:Shinjiro Kanae(School of Environment and Society, Tokyo Institute of Technology), Jun Matsumoto(Deaprtment of Geography, Tokyo Metropolitan University), Chairperson:Terao Toru(Faculty of Education, Kagawa University)

Asian monsoon system consists of variablities in wide range of scales ranging from diurnal to decadal. The diurnal variability is common in Asian region which is related with the surface heating due to insolation. Various types of meso-scale to synoptic disturbances such as meso-scale convective systems, monsoon depressions and tropical cyclones account for major part of the precipitation in this region. Intraseasonal variations themselves have multiple time scales such as quasi bi-weekly oscillatiion (QBW) and the boreal summer intraseasonal oscillation (BSISO). We have diverse types of seasonalities in different regions in Asia. Interannual variabilities, such as ENSO-monsoon and climate projections, are another intrinsic time scales of Asian monsoon that attract researchers.
These variabilities with specific spatio-temporal scales have mechanisms that are distinct from other types of variabilities. Our first target is to clarify the mechanisms of these specific variabilities. On the other hand, these multiple scale variabilities have strong interactions with each other. For example, diurnal variability interacts with all other variabilities with longer time scales. It has been shown that intraseasonal variabilities of precipitation highly depend on modulation of the activity of synoptic disturbances.
Especially variabilities with time scales longer than weeks have strong interaction with boundary conditions such as land surface, cryosphere, and ocean surface with 'memories' longer than weeks. Especially, highly non-linear land surface-convection coupling controls sub-seasonal to seasonal (S2S) monsoon variabilities and limits our predictability.
One of the focus of Asian precipitation experiment (AsiaPEX) is the multiple scale interaction in Asian monsoon system. We will exchange new development of studies on different time scales of variabilities and their interactions, and discuss on future development of our research activities.