气候变化领域集成服务门户(CCPortal): Assimilation of no-precipitation observations from Doppler radar with 4DVar and its impact on summertime convective event prediction

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DOI	10.1016/j.atmosres.2021.105617
	Assimilation of no-precipitation observations from Doppler radar with 4DVar and its impact on summertime convective event prediction
	Gao S.; Min J.; Yu H.
发表日期	2021
ISSN	0169-8095
卷号	257
英文摘要	No-precipitation reflectivity observations from Doppler radar contain valuable information on areas lacking precipitation; however, they are often ignored in four-dimensional variational (4DVar) radar data assimilation (DA). This study incorporated a neighborhood-based scheme to assimilate no-precipitation observations as a mechanism to suppress spurious convection. The impact of the scheme on convective forecasting using 4DVar was evaluated by comparing the performance of experiments with and without assimilation (ExpCTL) using eight diverse storm cases that occurred over the central United States during summer 2016. Three no-precipitation assimilation experiments with different neighborhood radiuses of 10 (ExpR10), 30 (ExpR30), and 50 km (ExpR50) were conducted to examine the sensitivity of the scheme to neighborhood size. Results indicated that all the no-precipitation assimilation experiments significantly improved quantitative precipitation forecast skill with large reduction of the bias and the false alarm ratio from ExpCTL, as well as improving representation of the intensity and coverage of the precipitation. The horizontal wind, temperature, and water vapor were also improved, especially the latter. The scheme was found sensitive to neighborhood size and greater benefit was found in ExpR30 in comparison with ExpR10 and ExpR50. Analysis revealed that ExpR30 reduced low-level cooling and mid-level warming corresponding to decreased water vapor in areas of overpredicted and false precipitation, and it was more effective in conserving the total water content balance during cycled radar DA. The findings of this study could provide reference information for assimilation of no-precipitation observations into the Weather Research and Forecasting model using 4DVar, which would be valuable for severe weather prediction. © 2021 Elsevier B.V.
英文关键词	4DVar; Data assimilation; Doppler radar; No-precipitation observations; Quantitative precipitation forecast
来源期刊	Atmospheric Research
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/236752
作者单位	Agronomy College, Shenyang Agricultural University, Shenyang, 110866, China; School of Atmospheric Sciences, Nanjing University of Information Science and Technology, Nanjing, 210044, China
推荐引用方式 GB/T 7714	Gao S.,Min J.,Yu H.. Assimilation of no-precipitation observations from Doppler radar with 4DVar and its impact on summertime convective event prediction[J],2021,257.
APA	Gao S.,Min J.,&Yu H..(2021).Assimilation of no-precipitation observations from Doppler radar with 4DVar and its impact on summertime convective event prediction.Atmospheric Research,257.
MLA	Gao S.,et al."Assimilation of no-precipitation observations from Doppler radar with 4DVar and its impact on summertime convective event prediction".Atmospheric Research 257(2021).