南海西南季风期NCEP2湍流热通量的质量分析

以5次南海现场观测试验数据(Xisha2002,Xisha2000,Xisha1998,Kexue 1和Shiyan 3)为参照,对NCEP2再分析资料中湍流热通量在南海西南季风期的精度进行了评估.结果表明NCEP2估算的潜热通量的平均值在试验Xisha2000,Xisha1998,Kexue 1和Shiyan 3期间分别高估了6(11%),2(2%),7(7%)和13W/m2(16%),而在Xisha2002试验中低估了10 W/m2(11%).在5个试验中低估的感热通量分别为7(130%),3(64%),7(170%),5(53%)和5 W/m2(72%).NCEP2与5个现场观测试验的时间序列的相关系数均没有达到95%的置信度.模式中湍流热通量损失的误差来源于基本变量和算法,基本变量中以海表温度和海面风速的误差产生的影响最大.应用COARE2.6a算法和NCEP2的基本变量重新计算的湍流热通量更加符合物理意义.

Evaluation of daily NCEP2 turbulent heat fluxes during southwest monsoon in South China Sea

The commonly usedturbulent heat fluxes in the National Centers for Environment Prediction-National Center for Atmospheric Research reanalysis 2(NCEP2) are evaluated using three air-sea flux research tower observations and two cruises in the South China Sea Monsoon experiment(SCSMEX)as the references.The mean latentheat fluxesfromNCEP2 areoverestimated 6(11%),2(2%),7(7%)and 13 W/m~(2)(16%) during experimentXisha2000,Xisha1998,Kexue 1 and Shiyan 3 respectivelyand underestimated10 W/m~(2)(11%) in Xisha2002.The overestimationsin sensible heat flux change from 7(130%),3(64%),7(170%),5(53%) to 5 W/m~(2)(72%) in Xisha2002,Xisha2000,Xisha1998,Kexue 1 and Shiyan 3 experiments.The correlations betweenthe time series of NCEP2 and the observations are relatively weak.The errors from the oceanicturbulent heat losses in NCEP2are mainly due to bulk variablesand algorithm.In all variables,the errors coming from sea surface temperature and wind speedare especially important.The results suggestthat the recalculated NCEP2 surface turbulent heat fluxesusing COARE algorithmare more physically reasonable,especially for latent heat flux.