Japan Geoscience Union Meeting 2016

Presentation information

International Session (Poster)

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

[A-CG06] Multi-scale ocean-atmosphere interaction in the tropics

Tue. May 24, 2016 5:15 PM - 6:30 PM Poster Hall (International Exhibition Hall HALL6)

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

5:15 PM - 6:30 PM

[ACG06-P05] Methods to evaluate prediction skill in the Madden-Julian oscillation phase space

*Yuiko Ichikawa1, Masaru Inatsu1 (1.Hokkaido University)

Keywords:Madden-Julian oscillation, predictability

Indices of prediction skill over the Madden-Julian oscillation (MJO) phase space are examined with reanalysis and forecast data provided by the Japan Meteorological Agency (JMA). In addition to the bivariate root-mean-square error (RMSE) and the bivariate anomaly correlation coefficient (ACC), the mean-error vector is assessed. Conventionally, the ACC and RMSE has been used, although this approach misses information on the model bias for MJO events. Moreover, the ACC is not suitable for models in which the MJO signal tends to damp in some phases, because the ACC strongly depends on the MJO amplitude. The mean-error vector compensates for this drawback by associating a model’s erroneous mean tendency with RMSE. For example, the JMA forecast produces a leftward mean error vector field uniformly distributed over the MJO phase space with its amplitude related to RMSE. RMSE should be then used with the mean error vector for evaluating MJO prediction skill.