Optimal Assimilation of Microwave Upper-Level Sounding Data in CMA-GFS  

作　　者：Changjiao DONG Hao HU Fuzhong WENG 

机构地区：[1]School of Atmospheric Physics,Nanjing University of Information Science and Technology,Nanjing 210044,China [2]CMA Earth System Modeling and Prediction Centre(CEMC),China Meteorological Administration,Beijing 100081,China [3]State Key Laboratory of Severe Weather,Chinese Academy of Meteorological Sciences,Beijing 100081,China

出　　处：《Advances in Atmospheric Sciences》2024年第10期2043-2060,共18页大气科学进展（英文版）

基　　金：supported by the Hunan Provincial Natural Science Foundation of China(Grant No.2021JC0009);the Natural Science Foundation of China(Grant Nos.U2142212 and 42105136)。

摘　　要：Various approaches have been proposed to minimize the upper-level systematic biases in global numerical weather prediction(NWP)models by using satellite upper-air sounding channels as anchors.However,since the China Meteorological Administration Global Forecast System(CMA-GFS)has a model top near 0.1 hPa(60 km),the upper-level temperature bias may exceed 4 K near 1 hPa and further extend to 5 hPa.In this study,channels 12–14 of the Advanced Microwave Sounding Unit A(AMSU-A)onboard five satellites of NOAA and METOP,whose weighting function peaks range from 10 to 2 hPa are all used as anchor observations in CMA-GFS.It is shown that the new“Anchor”approach can effectively reduce the biases near the model top and their downward propagation in three-month assimilation cycles.The bias growth rate of simulated upper-level channel observations is reduced to±0.001 K d^(–1),compared to–0.03 K d^(–1)derived from the current dynamic correction scheme.The relatively stable bias significantly improves the upper-level analysis field and leads to better global medium-range forecasts up to 10 days with significant reductions in the temperature and geopotential forecast error above 10 hPa.

关 键 词：CMA-GFS upper-level model bias anchoring bias correction satellite microwave data assimilation 

分 类 号：P407[天文地球—大气科学及气象学]