当前位置: X-MOL 学术Q. J. R. Meteorol. Soc. › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
The assimilation of microwave humidity sounder observations in all-sky conditions
Quarterly Journal of the Royal Meteorological Society ( IF 8.9 ) Pub Date : 2021-06-28 , DOI: 10.1002/qj.4115
Brett Candy 1 , Stefano Migliorini 1
Affiliation  

Numerical weather prediction (NWP) schemes use a wide variety of satellite observations to help constrain atmospheric analyses. Passive microwave humidity data from channels operating in the water vapour band at 183 GHz, such as those on the Microwave Humidity Sounder (MHS), are an important component of the satellite observing network. At this frequency the observations are very sensitive to scattering from ice crystals and, until recently, quality-control tests were used at the Met Office to exclude assimilation of these data in regions of strong scattering such as thick cirrus clouds. In the work described here we report on improvements to the pre-processing and assimilation of MHS data within the global NWP scheme at the Met Office, with the goal of utilising the data in scenes where liquid and ice cloud strongly affect the radiances. These improvements include the introduction of an observation operator that models the effects of ice scattering, and a scene-dependent observation error model. The error model is based on the estimated cloud ice and cloud liquid in the field of view. The new scheme has increased observation usage of MHS data over ocean by up to 40%. Trials have shown benefits to forecasts in both boreal summer and winter seasons. In the boreal summer period, for example, low-level wind forecast errors have improved in the Northern Hemisphere extratropics by up to 0.6%. Also, our experiments show evidence of significant improvements to the fit between observations and short-range forecasts for humidity-sensitive channels operating in both the microwave and infrared regions of the electromagnetic spectrum.

中文翻译:

全天条件下微波湿度探测器观测的同化

数值天气预报 (NWP) 计划使用各种卫星观测来帮助约束大气分析。来自在 183 GHz 水蒸气频段运行的通道(例如微波湿度测深仪 (MHS) 上的通道)的无源微波湿度数据是卫星观测网络的重要组成部分。在这个频率下,观测对冰晶的散射非常敏感,直到最近,气象局才使用质量控制测试来排除这些数据在强散射区域(如厚卷云)中的同化。在这里描述的工作中,我们报告了气象局全球 NWP 计划内 MHS 数据预处理和同化的改进,目的是在液体和冰云强烈影响辐射的场景中利用数据。这些改进包括引入了对冰散射效应进行建模的观测算子,以及与场景相关的观测误差模型。误差模型基于视场中估计的云冰和云液。新计划将海洋 MHS 数据的观测使用量增加了 40%。试验表明,对北方夏季和冬季的预报都有好处。例如,在北半球夏季,北半球温带地区的低空风预报误差提高了 0.6%。此外,我们的实验表明,在电磁频谱的微波和红外区域运行的湿度敏感通道的观测和短程预测之间的拟合显着改善的证据。
更新日期:2021-09-06
down
wechat
bug