沙尘浓度资料与AMSU辐射率资料同化在GRAPES_SDM沙尘暴模式中的应用

利用GRAPES_SDM沙尘暴模式及GRAPES_3DVAR系统,设计了4种试验,分别为没有同化的CTRL控制试验、仅同化探空资料的noPM试验、同时同化探空和PM10的PM试验和同时同化探空和AMSU辐射率资料的NOAA试验,对2011年4月28日-30日发生在中国北方地区的一次大范围沙尘暴过程进行了分析和对比模拟试验。结果发现：仅同化探空资料时,模式能够反映出沙尘天气系统的发展演变情况,但沙尘天气分布范围和强度的模拟效果没有明显改进；初始场中考虑了PM10沙尘浓度的分布后在很大程度上能够改善GRAPES_SDM沙尘暴模式对沙尘分布范围和强度的模拟效果；同化AMSU辐射率资料后,模式对500 hPa环流形势和200 hPa高空急流均有较好的模拟效果,从而模式对沙尘分布范围的模拟能力也有较好的改善,但对沙尘天气强度的模拟略有增强。这不仅说明PM10和ASMU辐射率资料的使用对于提高沙尘暴过程模拟效果是可行的、必要的,而且也为这两种资料用于沙尘暴预报奠定了一定基础。

An Application of Assimilated Dust Concentration Data and AMSU Satellite Radiance Data in GRAPES_SDM Model

Based on the GRAPES_SDM model and GRAPES_3DVAR data assimilation system, four experimental schemes are designed, they are CTRL experiment without data assimilation, noPM experiment that only assimilate sounding data, PM experiment that assimilate PM10 data and sounding data, NOAA experiment that assimilate sounding data and AMSU radiance data, then a large range sandstorm case from 28 April to 30 April in 2011 in northern China is analyzed. The model can reflect the development and evolvement of sand-dust weather system when only assimilating sounding data, but the simulation effect of sand-dust range and intensity have not obvious amelioration. The dust range and intensity can be simulated better by assimilating sounding and PM10 data. When assimilating AMSU radiance data, the model can assimilate the 500 hPa circulation pattern, 200 hPa high-level jet and dust range well, but intensify the dust strength a bit too much. It not only shows that the assimilation of PM10 and ASMU radiance data can improve the simulation effect of sand-dust process, but also lay a certain foundation for sand-dust weather forecast using the two data.