印度洋预报系统混合层深度预报检验

Verification of the Mixed Layer Depth of Indian Ocean Forecasting System

利用Argo浮标资料和Rama浮标资料对印度洋海洋环境数值预报系统2010-03-06—2013-05-31的24h混合层深度产品进行了预报精度检验。与Argo浮标数据对比表明:预报与观测绝对平均误差为13m,24h混合层深度预报平均偏浅10m以内;对苏门答腊岛附近海域(5°S^4°N,87°~99°E)的混合层深度预报平均偏浅20m,该海域预报平均风速偏小1.6m/s是可能原因;其它海域预报能力较高,尤其对热带中南印度洋区域(5°~17°S,63°~96°E)平均误差集中在-2~2m。分海域检验对比结果表明:该预报系统能很好的预测出阿拉伯海(60°~70°E,10°~20°N)和孟加拉湾(85°~93°E,10°~18°N)处混合层半年周期变化特征;热带南印度洋(60°~80°E,15°~19°S)混合层呈现明显季节变化特征,且在每年8,9月份达到最大值;热带外南印度洋(45°~70°E,0°~10°S)混合层常年较为浅薄;Argo与Rama数据所得结果一致;预报系统对上述特征均能很好地预测。

The forecasted 24 h mixed layer depth from March 6, 2010 to May 31, 2013 of the Indian ocean Forecasting System is verified for using Argo data and Rama data. Compared with the Argo data, the mean absolute error （MAE） between the forecasted and the observed mixed layer depth is 13 m, the 24h forecast is 10m shallower, and the forecast in Sumatra offshore area （5°S～4°N, 87°～99°E） is about 20m shallower due to the lower forecasted wind speed. The forecast accuracy is high in other regions especially in the tropical southern Indian ocean （5°～17°S,63°～96°E）, where the mean error is within -2～2 m. Verifica- tion further shows that the forecasting skill is high in simulating biannual variations in Arabian Sea （60°～ 70°E, 10°～20°N） and the Bay of Bengal （85°～93°E, 10°～18°N） and seasonal variation in tropical south- ern Indian ocean （60°～80°E, 15°～ 19°S） which reaches its maximum in August and September. The mixed layer is relatively shallower in extra-equatorial southern Indian Ocean （45°～70°E, 0°～10°S）. The results of Argo data and Rama data are consistent, and the forecasting system can well capture the above features.