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Korean Meteorological Society (한국기상학회)
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A Comparison of Accuracy of the Ocean Thermal Environments Using the Daily Analysis Data of the KMA NEMO/NEMOVAR and the US Navy HYCOM/NCODA

기상청 전지구 해양순환예측시스템(NEMO/NEMOVAR)과 미해군 해양자료 동화시스템(HYCOM/NCODA)의 해양 일분석장 열적환경 정확도 비교

  • Ko, Eun Byeol (Typhoon Research Center/Graduate School of Interdisciplinary Program in Marine Meteorology, Jeju National University) ;
  • Moon, Il-Ju (Typhoon Research Center/Graduate School of Interdisciplinary Program in Marine Meteorology, Jeju National University) ;
  • Jeong, Yeong Yun (Typhoon Research Center/Graduate School of Interdisciplinary Program in Marine Meteorology, Jeju National University) ;
  • Chang, Pil-Hun (National Institute of Meteorological Sciences)
  • 고은별 (제주대학교 해양기상학협동과정/태풍연구센터) ;
  • 문일주 (제주대학교 해양기상학협동과정/태풍연구센터) ;
  • 정영윤 (제주대학교 해양기상학협동과정/태풍연구센터) ;
  • 장필훈 (국립기상과학원)
  • Received : 2017.10.17
  • Accepted : 2017.12.21
  • Published : 2018.03.31
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Abstract

In this study, the accuracy of 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 NEMO) system and the HYbrid Coordinate Ocean Model/Navy Coupled Ocean Data Assimilation (HYCOM/NCODA, hereafter HYCOM) system, was evaluated using various oceanic observation data from March 2015 to February 2016. The evaluation was made for oceanic thermal environments in the tropical Pacific, the western North Pacific, and the Korean peninsula. NEMO generally outperformed HYCOM in the three regions. Particularly, in the tropical Pacific, the RMSEs (Root Mean Square Errors) of NEMO for both the sea surface temperature and vertical water temperature profile were about 50% smaller than those of HYCOM. In the western North Pacific, in which the observational data were not used for data assimilation, the RMSE of NEMO profiles up to 1000 m ($0.49^{\circ}C$) was much lower than that of HYCOM ($0.73^{\circ}C$). Around the Korean peninsula, the difference in RMSE between the two models was small (NEMO, $0.61^{\circ}C$; HYCOM, $0.72^{\circ}C$), in which their errors show relatively big in the winter and small in the summer. The differences reported here in the accuracy between NEMO and HYCOM for the thermal environments 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. The present results can be used as a basic data to evaluate the accuracy of NEMO, before it becomes the operational model of the KMA providing real-time ocean analysis and prediction data.

Keywords

References

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