Improved decadal climate prediction in the North Atlantic using EnOI-assimilated initial condition

Min Wei; Qingquan Li; Xiaoge Xin; Wei Zhou; Zhenyu Han; Yong Luo; Zongci Zhao

doi:10.1016/j.scib.2017.08.012

Improved decadal climate prediction in the North Atlantic using EnOI-assimilated initial condition

Sci Bull (Beijing). 2017 Aug 30;62(16):1142-1147. doi: 10.1016/j.scib.2017.08.012. Epub 2017 Aug 10.

Authors

Min Wei¹, Qingquan Li², Xiaoge Xin³, Wei Zhou⁴, Zhenyu Han⁵, Yong Luo⁶, Zongci Zhao⁶

Affiliations

¹ Ministry of Education Key Laboratory for Earth System Modeling, Department of Earth System Science, Tsinghua University, Beijing 100084, China; Joint Center for Global Change Studies, Beijing 100875, China; National Meteorological Information Center, China Meteorological Administration, Beijing 100081, China.
² Laboratory for Climate Studies, National Climate Center, China Meteorological Administration, Beijing 100081, China; Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters, Nanjing University of Information Science and Technology, Nanjing 210044, China. Electronic address: liqq@cma.gov.cn.
³ Laboratory for Climate Studies, National Climate Center, China Meteorological Administration, Beijing 100081, China. Electronic address: xinxg@cma.gov.cn.
⁴ State Key Laboratory of Tropical Oceanography, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China.
⁵ Laboratory for Climate Studies, National Climate Center, China Meteorological Administration, Beijing 100081, China.
⁶ Ministry of Education Key Laboratory for Earth System Modeling, Department of Earth System Science, Tsinghua University, Beijing 100084, China; Joint Center for Global Change Studies, Beijing 100875, China.

PMID: 36659345
DOI: 10.1016/j.scib.2017.08.012

Abstract

Decadal prediction experiments of Beijing Climate Center climate system model version 1.1 (BCC-CSM1.1) participated in Coupled Model Intercomparison Project Phase 5 (CMIP5) had poor skill in extratropics of the North Atlantic, the initialization of which was done by relaxing modeled ocean temperature to the Simple Ocean Data Assimilation (SODA) reanalysis data. This study aims to improve the prediction skill of this model by using the assimilation technique in the initialization. New ocean data are firstly generated by assimilating the sea surface temperature (SST) of the Hadley Centre Sea Ice and Sea Surface Temperature (HadISST) dataset to the ocean model of BCC-CSM1.1 via Ensemble Optimum Interpolation (EnOI). Then a suite of decadal re-forecasts launched annually over the period 1961-2005 is carried out with simulated ocean temperature restored to the assimilated ocean data. Comparisons between the re-forecasts and previous CMIP5 forecasts show that the re-forecasts are more skillful in mid-to-high latitude SST of the North Atlantic. Improved prediction skill is also found for the Atlantic multi-decadal oscillation (AMO), which is consistent with the better skill of Atlantic meridional overturning circulation (AMOC) predicted by the re-forecasts. We conclude that the EnOI assimilation generates better ocean data than the SODA reanalysis for initializing decadal climate prediction of BCC-CSM1.1 model.

Keywords: AMO; BCC-CSM; Decadal prediction; EnOI; Initialization.