Experimental Dynamical Forecast of an MJO Event Observed during TOGA-COARE Period  

作　　者：Xiouhua Fu Bin Wang BAO Qing Ping Liu Bo Yang 

机构地区：[1]IPRC, SOEST, University of Hawaii at Manoa, Honolulu, HI 96822 [2]Department of Meteorology, SOEST, Universiry of Hawaii at Manoa, Honolulu, HI 96822 [3]LASG Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China

出　　处：《Atmospheric and Oceanic Science Letters》2008年第1期24-28,共5页大气和海洋科学快报（英文版）

基　　金：supported by NASA Earth Science Program, NSF Climate Dynamics Program;the Japan Agency for Marine-Earth Science and Technology (JAMSTEC), NASA;NOAA through their sponsorship of the IPRC;supported by APEC Climate Center (APCC) as a part of APCC international research project

摘　　要：With a hybrid atmosphere-ocean coupled model we carried out an experimental forecast of a well documented Madden-Julian Oscillation (MJO) event that was observed during the period of Tropical Ocean Global Atmosphere Coupled Ocean-Atmosphere Response Experiment (TOGA-COARE). The observed event, originated in the western Indian Ocean around 6 January 1993, moved eastward with a phase speed of about 6.2 m s 1 and reached the dateline around February 1. The hybrid coupled model reasonably forecasts the MJO initiation in the western Indian Ocean, but the predicted MJO event propagates too slow (～ 4.4 m s 1 ). Results from previous observational studies using unprecedented humidity profiles obtained by NASA Aqua/AIRS satellite suggested that two potential physical processes may be responsible for this model caveat. After improving the cumulus parameterization scheme based on the observations, the model is able to forecast the same event one month ahead. Further sensitivity experiment confirms that the speed-up of model MJO propagation is primarily due to the improved convective scheme. Further, air-sea coupling plays an important role in maintaining the intensity of the predicted MJO. The results here suggest that MJO prediction skill is sensitive to model cumulus parameterization and air-sea coupling.With a hybrid atmosphere-ocean coupled model we carried out an experimental forecast of a well documented Madden-Julian Oscillation （MJO） event that was observed during the period of Tropical Ocean Global Atmosphere Coupled Ocean-Atmosphere Response Experiment （TOGA-COARE）. The observed event, originated in the western Indian Ocean around 6 January 1993, moved eastward with a phase speed of about 6.2 m s^-1 and reached the dateline around February 1. The hybrid coupled model reasonably forecasts the MJO initiation in the western Indian Ocean, but the predicted MJO event propagates too slow （- 4.4 m s^-1）. Results from previous observational studies using unprecedented humidity profiles obtained by NASA Aqua/AIRS satellite suggested that two potential physical processes may be responsible for this model caveat. After improving the cumulus parameterization scheme based on the observa- tions, the model is able to forecast the same event one month ahead. Further sensitivity experiment confirms that the speed-up of model MJO propagation is primarily due to the improved convective scheme. Further, air-sea coupling plays an important role in maintaining the intensity of the predicted MJO. The results here suggest that MJO prediction skill is sensitive to model cumulus parameterization and air-sea coupling.

关 键 词：MJO dynamic forecast cumulus parameterization air-sea coupling TOGA-COARE 

分 类 号：P7[天文地球—海洋科学]