한국 기상청과 미해군 해양순환예측시스템의 수온 분석장 정확도 비교

Abstract

In this study, the accuracy of the two ocean analysis data, which are produced from the Korea Meteorological Administration (KMA) Nucleus for European Modelling of the Ocean/Variational Data Assimilation (NEMO/NEMOVAR, hereafter KMA NEMO) system and the United States (US) HYbrid Coordinate Ocean Model/Navy Coupled Ocean Data Assimilation (HYCOM/NCODA, hereafter US Navy HYCOM) system, was evaluated using various oceanic observation data from March 2015 to February 2016. The evaluation was made for the water temperature in the tropical Pacific, the western North Pacific, and the Korean peninsula. Overall results reveal that the KMA NEMO generally outperformed the US Navy HYCOM in the three regions. Particularly, for the Tropical Atmosphere Ocean project (TAO) buoys, the accuracy of the KMA NEMO for both the sea surface temperature and vertical water temperature profile was about two times higher than that of the US Navy HYCOM. For the Japan Meteorological Administration (JMA）vessel observation data in the western North Pacific, which were not used for data assimilation, the RMSE (Root Mean Square Error) of the KMA NEMO profiles up to 1000m (0.49oC) was much lower than that of the US Navy HYCOM (0.73oC). For the KMA Ocean buoys around the Korean peninsula, the errors of the two models were large in the winter and small in the summer, but their differences in RMSE were small (NEMO, 0.61oC; HYCOM, 0.72oC). The differences in the accuracy between the KMA NEMO and the US Navy HYCOM for the water temperature may be attributed to horizontal and vertical resolutions of the models, vertical coordinate and mixing scheme, data quality control system, data used for data assimilation, and atmosphere forcing. These findings can be used as basic information before the KMA NEMO becomes the operational model of the KMA, which provides real-time ocean analysis and prediction data for regional ocean modeling and typhoon-ocean coupled predictions.