Residual Diagnosis of Diabatic Heating from ERA-40 and NCEP Reanalyses: Intercomparisons with TRMM
Residual Diagnosis of Diabatic Heating from ERA-40 and NCEP Reanalyses: Intercomparisons with TRMM
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DOI：
10.1175/2008jcli2417.1
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发表时间：
2009-01
影响因子：
4.9
通讯作者：
S. Chan;S. Nigam
中科院分区：
文献类型：
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作者：
S. Chan;S. Nigam
非绝热加热诊断从40年ECMWF再分析（ERA-40）的循环作为残余的热力学方程。将加热分布与NCEP和15年ECMWF再分析（ERA-15）环流诊断的加热结构以及热带降雨测量使命（TRMM）观测使用对流分层加热（CSH）算法产生的潜热进行比较。热带地区的ERA-40剩余加热被发现比NCEP（和ERA-15）更强，特别是在7月，其纬向垂直平均值是其两倍。1月份海洋大陆和7月份东部盆地和非洲的偏差最强。与降水量的比较表明，ERA-40的加热在东太平洋更为现实，但在海洋大陆过度，1月份至少增加了20%。从加热廓线积分和站和卫星分析的降水估计的相互比较揭示了TRMM CSH潜热加热是长期弱的多达2的一个因素！在四个分析区域中的三个区域，它是九个降水估计值中的低端异常值。同样令人担忧的是热带地区CSH潜热加热廓线的积分与TRMM降水反演之间的不一致，这限制了CSH算法（例如，3A 25分析）。面对TRMM的诊断潜热加热当地降水反演和当地积云模式加热廓线与加热的基础上的大尺度同化环流伊萨本研究的定义属性。
Diabatic heating is diagnosed from the 40-yr ECMWF Re-Analysis (ERA-40) circulation as a residue in the thermodynamic equation. The heating distribution is compared with the heating structure diagnosed from NCEP and 15-yr ECMWF Re-Analysis (ERA-15) circulation and latent heating generated from Tropical Rainfall Measuring Mission (TRMM) observations using the convective‐stratiform heating (CSH) algorithm. The ERA-40 residual heating in the tropics is found to be stronger than NCEP’s (and ERA-15), especially in July when its zonal‐vertical average is twice as large. The bias is strongest over the Maritime Continent in January and over the eastern basins and Africa in July. Comparisons with precipitation indicate ERA-40 heating to be much more realistic over the eastern Pacific but excessive over the Maritime Continent, by at least 20% in January. Intercomparison of precipitation estimates from heating-profile integrals and station and satellite analyses reveals the TRMM CSH latent heating to be chronically weak by as much as a factor of 2! It is the low-side outlier among nine precipitation estimates in three of the four analyzed regions. No less worrisome is the inconsistency between the integral of the CSH latent heating profile in the tropics and the TRMM precipitation retrievals constraining the CSH algorithm (e.g., the 3A25 analysis). Confronting TRMM’s diagnosis of latent heating from local rainfall retrievals and local cumulus-model heatingprofileswith heating basedon the large-scaleassimilated circulation isa defining attribute ofthis study.