We held the 52nd Data Assimilation Seminar at RIKEN Center for Computational Science (R-CCS) on December 19. The seminar talk was given by Dr Tetsuo Nakazawa from Meteorological Research Institute (MRI), Japan Meteorological Agency (JMA).
Dr Nakazawa spoke about his research on tropical cyclone frequency under a warmer climate scenario and why it may be expected that the annual number of tropical cyclones may decrease in the future.
We would like to thank Dr Nakazawa very much for visiting us at RIKEN. We look forward to his next visit!
Date： *Wednesday 19 December 2018, 15:30-16:30 * Place： Seminar Room at R-CCS Language: English Speaker： Dr. Tetsuo Nakazawa (Meteorological Research Institute (MRI))
*Title: Is the Trend in Tropical Cyclone Formation Frequency due to Global Warming?*
Under the warmer climate projection, several models simulate that the annual number of tropical cyclone formation will decrease, but the intense tropical cyclone number will increase globally. The former may be related with the stabler condition of the atmosphere, and the latter may be related with the possible rapid intensification under the more humid condition near the surface. To understand the former hypothesis, Arakawa and Schubert’s cumulus parameterization method has been utilized to estimate all possible cloud types at each grid, using the ECMWF reanalysis dataset (ERA20C) from 1900 to 2010. The result shows that the tropical atmosphere is getting stabler and the cloud top height of the deepest cloud type is getting lower. This may explain why the annual number the tropical cyclone formation will decrease in future.