气候变化领域集成服务门户(CCPortal): Exploring the use of underground gravity monitoring to evaluate radar estimates of heavy rainfall

CCPortal

DOI	10.5194/hess-23-93-2019
	Exploring the use of underground gravity monitoring to evaluate radar estimates of heavy rainfall
	Delobbe L.; Watlet A.; Wilfert S.; Van Camp M.
发表日期	2019
ISSN	1027-5606
起始页码	93
结束页码	105
卷号	23 期号:1
英文摘要	The radar-based estimation of intense precipitation produced by convective storms is a challenging task and the verification through comparison with gauges is questionable due to the very high spatial variability of such types of precipitation. In this study, we explore the potential benefit of using a superconducting gravimeter as a new source of in situ observations for the evaluation of radar-based precipitation estimates. The superconducting gravimeter used in this study is installed in Membach (BE), 48 m underneath the surface, at 85 km distance from a C-band weather radar located in Wideumont (BE). The 15-year observation record 2003-2017 is available for both gravimeter and radar with 1 and 5 min time steps, respectively. Water mass increase at ground due to precipitation results in a decrease in underground measured gravity. The gravimeter integrates soil water in a radius of about 400 m around the instrument. This allows capture of rainfall at a larger spatial scale than traditional rain gauges. The precision of the gravimeter is a few tenths of nm s -2 , 1 nm s -2 corresponding to 2.6 mm of water. The comparison of reflectivity and gravity time series shows that short-duration intense rainfall events produce a rapid decrease in the underground measured gravity. A remarkable correspondence between radar and gravimeter time series is found. The precipitation amounts derived from gravity measurements and from radar observations are further compared for 505 rainfall events. A correlation coefficient of 0.58, a mean bias (radar-gravimeter)/gravimeter of 0.24 and a mean absolute difference (MAD) of 3.19 mm are obtained. A better agreement is reached when applying a hail correction by truncating reflectivity values to a given threshold. No bias, a correlation coefficient of 0.64 and a MAD of 2.3 mm are reached using a 48 dBZ threshold. The added value of underground gravity measurements as a verification dataset is discussed. The two main benefits are the spatial scale at which precipitation is captured and the interesting property that gravity measurements are directly influenced by water mass at ground no matter the type of precipitation: hail or rain. © Author(s) 2019.All Rights Reserved.
语种	英语
scopus关键词	Gravimeters; Gravitation; Meteorological radar; Oceanography; Rain; Rain gages; Reflection; Soil moisture; Time series; Correlation coefficient; In-situ observations; Intense precipitation; Mean absolute differences; Observation records; Reflectivity values; Spatial variability; Superconducting gravimeter; Radar measurement; data set; gravimetry; precipitation intensity; radar; raingauge; reflectivity; soil water; storm; time series; water mass; Belgium; Liege [Belgium]; Membach
来源期刊	Hydrology and Earth System Sciences
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/159799
作者单位	Delobbe, L., Royal Meteorological Institute of Belgium, Brussels, 1180, Belgium; Watlet, A., Royal Observatory of Belgium, Brussels, 1180, Belgium; Wilfert, S., Institute of Geography, University of Augsburg, Augsburg, Germany; Van Camp, M., Royal Observatory of Belgium, Brussels, 1180, Belgium
推荐引用方式 GB/T 7714	Delobbe L.,Watlet A.,Wilfert S.,et al. Exploring the use of underground gravity monitoring to evaluate radar estimates of heavy rainfall[J],2019,23(1).
APA	Delobbe L.,Watlet A.,Wilfert S.,&Van Camp M..(2019).Exploring the use of underground gravity monitoring to evaluate radar estimates of heavy rainfall.Hydrology and Earth System Sciences,23(1).
MLA	Delobbe L.,et al."Exploring the use of underground gravity monitoring to evaluate radar estimates of heavy rainfall".Hydrology and Earth System Sciences 23.1(2019).