DOI: 10.1007/s00382-014-2063-2
Scopus记录号: 2-s2.0-84893173280
论文题名: An assessment of the ENSO forecast skill of GEOS-5 system
作者: Ham Y.-G. ; Schubert S. ; Vikhliaev Y. ; Suarez M.J.
刊名: Climate Dynamics
ISSN: 9307575
出版年: 2014
卷: 43, 期: 2017-09-10 起始页码: 2415
结束页码: 2430
语种: 英语
英文摘要: The seasonal forecast skill of the NASA Global Modeling and Assimilation Office atmosphere–ocean coupled global climate model (AOGCM) is evaluated based on an ensemble of 9-month lead forecasts for the period 1993 to 2010. The results from the current version (V2) of the AOGCM consisting of the GEOS-5 AGCM coupled to the MOM4 ocean model are compared with those from an earlier version (V1) in which the AGCM (the NSIPP model) was coupled to the Poseidon Ocean Model. It was found that the correlation skill of the Sea Surface Temperature (SST) forecasts is generally better in V2, especially over the sub-tropical and tropical central and eastern Pacific, Atlantic, and Indian Ocean. Furthermore, the improvement in skill in V2 mainly comes from better forecasts of the developing phase of ENSO from boreal spring to summer. The skill of ENSO forecasts initiated during the boreal winter season, however, shows no improvement in terms of correlation skill, and is in fact slightly worse in terms of root mean square error (RMSE). The degradation of skill is found to be due to an excessive ENSO amplitude. For V1, the ENSO amplitude is too strong in forecasts starting in boreal spring and summer, which causes large RMSE in the forecast. For V2, the ENSO amplitude is slightly stronger than that in observations and V1 for forecasts starting in boreal winter season. An analysis of the terms in the SST tendency equation, shows that this is mainly due to an excessive zonal advective feedback. In addition, V2 forecasts that are initiated during boreal winter season, exhibit a slower phase transition of El Nino, which is consistent with larger amplitude of ENSO after the ENSO peak season. It is found that this is due to weak discharge of equatorial Warm Water Volume (WWV). In both observations and V1, the discharge of equatorial WWV leads the equatorial geostrophic easterly current so as to damp the El Nino starting in January. This process is delayed by about 2 months in V2 due to the slower phase transition of the equatorial zonal current from westerly to easterly. © 2014, Springer-Verlag Berlin Heidelberg. 资助项目: KMA, Korea Meteorological Administration
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/54384
Appears in Collections: 过去全球变化的重建
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作者单位: Global Modeling and Assimilation Office, GSFC/NASA, Greenbelt, MD, United States; Goddard Earth Sciences Technology and Research Studies and Investigations, Morgan State University, Baltimore, MD, United States; Chonnam National University, Gwangju, South Korea; Goddard Earth Sciences Technology and Research Studies and Investigations, Universities Space Research Association, Columbia, MD, United States
Recommended Citation:
Ham Y.-G.,Schubert S.,Vikhliaev Y.,et al. An assessment of the ENSO forecast skill of GEOS-5 system[J]. Climate Dynamics,2014-01-01,43(2017-09-10)