AOGS 17th Annual Meeting

SS01 – The Asian Monsoon in a Changing Climate

Thu-02 Jul 2020 | 13:30 – 15:30 | Tower B, Lavender II Akio KITOH Japan Meteorological Business Support Center “Monsoon Precipitation Changes Simulated by Large-ensemble MRI-AGCM”

Akio KITOH^1#+, Hirokazu ENDO²

¹Japan Meteorological Business Support Center, ²Japan Meteorological Agency

We study past and future changes of monsoon precipitation based on large ensemble experiments with a 60-km mesh Meteorological Research Institute (MRI) atmospheric general circulation model (AGCM). Experiments include pre-industrial (~1850), historical (1951–2010), and future simulations for 2°C and 4°C warming from pre-industrial. In a future climate simulation, SST changes derived from CMIP5 models are added to the present-day observed SST. In the present-day climate realizations, which are forced by the observed sea surface temperature (SST), this AGCM shows high performance in reproducing mean as well as extreme precipitation. Compared with pre-industrial, present-day climate shows significant increases in global monsoon precipitation and some regional (East Asia, South Asia, South America, South Africa) monsoon precipitation, with further increases by additional warming. Extreme heavy precipitation is projected to increase with higher rates than mean precipitation except some regions around the western tropical Pacific, where a significant decrease of tropical cyclone frequency is projected in future. The ensemble size enables us to examine changes of rare events. The 90- and 99-percentile values of the annual maximum 1-day precipitation associated with tropical cyclones are projected to increase in a region extending from Hawaii to the south of Japan. Future changes of tropical cyclone activity are largely influenced by differences in prescribed future SST warming patterns, and thus a source of large uncertainty.

Biography

Akio Kitoh was born in 1953 in Osaka, Japan. He has B.Sc. (1975), M.S. (1977) and D.Sc. (1991) in Geophysics from Kyoto University. He was Director at Climate Research Department, Meteorological Research Institute, Japan Meteorological Agency during 2007–2013; and Senior Researcher, Faculty of Life and Environmental Sciences, University of Tsukuba during 2013–2017. He is at Office of Climate and Environmental Research Promotion, Japan Meteorological Business Support Center since 2017. He was Lead Author of the Second, Third, Fourth and Fifth Assessment Report of IPCC WGI, and is Lead Author of the Sixth Assessment Report of IPCC WGII. His research interest includes climate modeling, climate varianlity, monsoon, climate change for paleo and future. He is currently engaged in Integrated Climate Change Projection (TOUGOU: Integrated Climate Model Advanced Research Program). He has about 200 co-authored articles.