Japan Geoscience Union Meeting 2015

Presentation information

Oral

Symbol A (Atmospheric and Hydrospheric Sciences) » A-CG Complex & General

[A-CG32] Multi-scale ocean-atmosphere interaction in the tropics

Tue. May 26, 2015 4:15 PM - 6:00 PM 202 (2F)

Convener:*Hiroki Tokinaga(Disaster Prevention Research Institute/Hakubi Center, Kyoto Univesity), Takuya Hasegawa(Japan Agency for Marine-Earth Science and Technology), Ayako Seiki(Japan Agency for Marine-Earth Science and Technology), Tomoki Tozuka(Department of Earth and Planetary Science, Graduate School of Science, The University of Tokyo), Motoki Nagura(Japan Agency for Marine-Earth Science and Technology), Masamichi Ohba(Central Research Institute of Electric Power Industry (CRIEPI), Environmental Science Research Laboratory), Yukiko Imada(Atmosphere and Ocean Research Institute, the University of Tokyo), Chair:Motoki Nagura(Japan Agency for Marine-Earth Science and Technology), Yukiko Imada(Meteorological Research Institute, Japan Meteorological Agency)

5:10 PM - 5:25 PM

[ACG32-10] An AGCM study on precipitation anomalies associated with Ningaloo Nino

*Tomoki TOZUKA1, Takahito KATAOKA1, Toshio YAMAGATA2 (1.The University of Tokyo, 2.Application Laboratory, JAMSTEC)

Keywords:Ningaloo Nino, Precipitation, Atmospheric General Circulation Model, El Nino/Southern Oscillation

Ningaloo Nino (Nina) is a recently identified climate mode associated with positive (negative) sea surface temperature (SST) anomalies off the west coast of Australia and wet (dry) anomalies in the northwestern part of Australia. However, previous studies could not isolate its influences based on statistical analyses of observational precipitation data, because the precipitation over Australia is also influenced by tropical climate modes such as El Nino/Southern Oscillation and the Indian Ocean Dipole. Based on a series of experiments with an atmospheric general circulation model, we have examined whether Ningaloo Nino/Nina alone can induce precipitation anomalies. It is shown that even when SST is allowed to vary interannually only in the eastern South Indian Ocean and the monthly climatology of SST is imposed elsewhere, Ningaloo Nino (Nina) induces wet (dry) anomalies in the northwestern part of Australia.