Forecast Verification For Wave-circulation Coupled Numerical Model Operational Forecast System

This paper does the forecast verification for wave-circulation coupled numericalmodel operational forecast system for Global and Indian Ocean, which is developedby the First Institute of Oceanography SOA. The forecast results of24,48and72hours are verified using the wave height data of Jason-2and the NDBC, SST data ofAVHRR and TAO/TRITON(Pacific)，PIRATA(Atlantic)，RAMA(Indian) buoys, andTemperature profile data of Argo, this paper has given the verified results for thesignificant wave height, SST, temperature profiles and mixed layer depth. The timeof forecast verification is totally47months, from Jan2010to Nov2013.First，The global forecast system is verified. The24hours forecasting mean errorof the significant wave height is between0.13m and0.33m, the mean absoluteerror is between0.41m and0.51m, the root mean square error is between0.54m and0.67m, the scatter index is between0.19and0.22. The48hours forecasting meanerror of the significant wave height is between0.14m and0.33m, the mean absoluteerror is between0.43m and0.53m, the root mean square error is between0.58m and0.71m, the scatter index is between0.20and0.25. The72hours forecasting meanerror of the significant wave height is between0.13m and0.33m, the mean absoluteerror is between0.47m and0.56m, the root mean square error is between0.63m and0.75m, the scatter index is between0.23and0.25. The forecast wave height is largerabout0.65m than observed wave height in Equatorial Pacific(20oS-10oN，150oE-120oW), the forecast error increase with the increasing of the forecast period,especially in the North Pacific and the south of45°S. The forecast SST is about2℃lower than observed SST in Pacific Northwest(25oN-45oN，150oE-150oW) and inSoutheast of North America(30oN-50oN，30oW-60oW), and the error is largest in Northern Hemisphere Summer; The forecast SST is about2℃lower than observedSST near the Equator between130oW-180oW, and the error is largest in NorthernHemisphere Summer and Spring; the forecast results of SST is good in other regionexcept boundary, the mean absolute error is between0℃and1℃. The mean error forthe forecast SST is between0.05℃and0.5℃, the mean absolute error is between0.75℃and1.05℃in Global Area. The mean error for temperature profiles isbetween-0.26m and-0.36m, the mean absolute error is between0.81℃and0.90℃,the root mean square error is between1.19℃and1.35℃. Overall, the difference ofthe forecast sea surface temperature and temperature profiles for24，48and72hoursis very small.Second, The Indian Ocean forecast system is verified. The24h forecast mixedlayer depth is verified for the Forecasting System in Indian ocean, using Argo dataand Rama data from March6,2010to May31,2013. The results of verification usingArgo data is that the mean absolute error (MAE) is13m; the mixed layer for24hforecast is shallow10m or less; the forecast mixed layer depth is about20metersshallower than the Argo in Sumatra offshore (5oS–4oN,87o–99oE); the forecastaccuracy is good in other region, especially in the tropical southern Indianocean(5o-17oS,63o-96oE), the mean error is among-2～2m. The region results ofverification is that the forecasting system forecasts well the half-cycle variation of themixed layer in Arabian Sea (60o-70oE,10o-20oN) and the Bay ofBengal(85o-93oE,10o-18oN); the mixed layer shows significant seasonal variation inthe tropical southern Indian ocean (60o-80oE,15o-19oS), and reaches its maximum inAugust and September each year; the mixed layer is perennial relatively shallow inthe extra-equatorial southern Indian ocean (45o-70oE,0o-10oS); the results of Argo dataand Rama data are consistent; the forecasting system for the above features can bewell forecasted.