时间加密探空观测对分析和预报质量的敏感性研究
投稿时间: 2017-12-19  最后修改时间: 2018-03-05  点此下载全文
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作者单位E-mail
马旭林 南京信息工程大学大气科学学院 xulinma@nuist.edu.cn 
原榕 南京信息工程大学大气科学学院  
秦璐瑶 南京信息工程大学  
郭启云 中国气象局气象探测中心  
基金项目:国家自然科学基金项目(面上项目,重点项目,重大项目);国家重点基础研究发展计划(973计划)
中文摘要:探空观测是气象资料同化中最基本的常规观测资料,因其资料质量较高,对同化分析和预报的有效改善具有重要作用。但由于探空观测站的空间分辨率低,每日仅有两次观测而数量偏少,且分布不均匀,在一定程度上限制了其分析场对中小尺度大气状态的准确再现能力。自我国L波段雷达-数字探空仪更新换代以来,探空观测系统具备了获取每日4次、垂直分辨为秒级和分钟级的探空资料。本文利用WRF中尺度数值模式,通过06 UTC加密探空资料和12 UTC常规探空资料的有效同化,研究分析了时间加密探空观测资料对同化分析和预报质量的敏感性影响。结果表明:同化06 UTC时间加密探空资料对午后暴雨预报质量优于12 UTC常规探空观测。具体而言,同化06 UTC时间加密探空资料预报的大雨和暴雨的预报技巧高于12 UTC常规探空资料;位势高度、温度和风场等预报场的均方根误差在高层的改进效果更加明显;06 UTC时间加密探空资料的同化对高层的高空急流和低层的水汽通量散度的预报质量贡献更大。批量试验进一步证实了同化06 UTC时间加密探空资料对分析和数值预报效果改进的积极意义。
中文关键词:数值模拟 资料同化 探空资料 加密观测
 
Study on sensitivity of intensive temporal radiosounde observations to analysis and forecast quality
Abstract:The sounding data is the most basic routine observation in data assimilation. Because of its high data quality, sounding data plays an important role in the effective improvement of analysis fields and forecast results. However, accessing to sounding data twice a day limits the accuracy of small and medium-sized analysis fields of atmospheric conditions to go further because of the low spatial resolution, the small quantities and the uneven distributions of the radiosonde stations. After the L-band radar-digital sounding system in our country has been updated, the sounding system could obtain the sounding data 4 times a day with high vertically spatial resolution and second-level and minute-level time resolution. In this paper, the WRF mesoscale numerical model is used to analyze the sensitivity of sounding data to the assimilation analysis and forecast quality through the 06 UTC intensive sounding data and 12 UTC conventional sounding data. It was concluded that: the improvement of the analysis field and forecast effects is obvious when assimilation 06 UTC intensive sounding data with the sparse of 30s intervals. At the same time, the forecast results of assimilating 06 UTC intensive sounding data are close or even better than that of the 12 UTC conventional sounding data. To be specific, prediction grades of heavy rain and rainstorm by assimilating 06 UTC intensive sounding data are more accurate than by assimilating 12 UTC conventional sounding data. The root mean square error of prediction fields such as geopotential height, temperature and wind field is more effective at higher levels. The assimilation of the intensive sounding data at 06 UTC contributes more to the forecast quality of upper-level jet stream and lower-level water vapor flux divergence. Continuous 30 days tests further confirm that assimilating 06 UTC intensive sounding data is of positive significance for both analysis fields and numerical forecasting.
keywords:numerical simulation  data assimilation  radiosounde data  intensive temporal observations
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