气候变化领域集成服务门户(CCPortal): Use of Sentinel-1 radar observations to evaluate snowmelt dynamics in alpine regions

CCPortal

DOI	10.5194/tc-14-935-2020
	Use of Sentinel-1 radar observations to evaluate snowmelt dynamics in alpine regions
	Marin C.; Bertoldi G.; Premier V.; Callegari M.; Brida C.; Hürkamp K.; Tschiersch J.; Zebisch M.; Notarnicola C.
发表日期	2020
ISSN	19940416
起始页码	935
结束页码	956
卷号	14 期号:3
英文摘要	Knowing the timing and the evolution of the snow melting process is very important, since it allows the prediction of (i) the snowmelt onset, (ii) the snow gliding and wet-snow avalanches, (iii) the release of snow contaminants, and (iv) the runoff onset. The snowmelt can be monitored by jointly measuring snowpack parameters such as the snow water equivalent (SWE) or the amount of free liquid water content (LWC). However, continuous measurements of SWE and LWC are rare and difficult to obtain. On the other hand, active microwave sensors such as the synthetic aperture radar (SAR) mounted on board satellites are highly sensitive to LWC of the snowpack and can provide spatially distributed information with a high resolution. Moreover, with the introduction of Sentinel-1, SAR images are regularly acquired every 6 d over several places in the world. In this paper we analyze the correlation between the multitemporal SAR backscattering and the snowmelt dynamics. We compared Sentinel-1 backscattering with snow properties derived from in situ observations and process-based snow modeling simulations for five alpine test sites in Italy, Germany and Switzerland considering 2 hydrological years. We found that the multitemporal SAR measurements allow the identification of the three melting phases that characterize the melting process, i.e., moistening, ripening and runoff. In particular, we found that the C-band SAR backscattering decreases as soon as the snow starts containing water and that the backscattering increases as soon as SWE starts decreasing, which corresponds to the release of meltwater from the snowpack. We discuss the possible reasons of this increase, which are not directly correlated to the SWE decrease but to the different snow conditions, which change the backscattering mechanisms. Finally, we show a spatially distributed application of the identification of the runoff onset from SAR images for a mountain catchment, i.e., the Zugspitze catchment in Germany. Results allow us to better understand the spatial and temporal evolution of melting dynamics in mountain regions. The presented investigation could have relevant applications for monitoring and predicting the snowmelt progress over large regions. © 2020 Museum National d'Histoire Naturelle. All rights reserved.
英文关键词	gliding; image analysis; melting; meltwater; radar; ripening; runoff; Sentinel; snow water equivalent; snowmelt; synthetic aperture radar; temporal evolution; water content; Alps; Bavaria; Bavarian Alps; Central Alps; Germany; Italy; Switzerland; Wetterstein Mountains; Zugspitze
语种	英语
来源期刊	Cryosphere
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/202153
作者单位	Institute for Earth Observation, Eurac Research, Viale Druso 1, Bolzano, 39100, Italy; Institute for Alpine Environment, Eurac Research, Viale Druso, 1, Bolzano, 39100, Italy; Helmholtz Zentrum München, German Research Center for Environmental Health, Institute of Radiation Medicine, Ingolstädter Landstraße 1, Neuherberg, 85764, Germany
推荐引用方式 GB/T 7714	Marin C.,Bertoldi G.,Premier V.,et al. Use of Sentinel-1 radar observations to evaluate snowmelt dynamics in alpine regions[J],2020,14(3).
APA	Marin C..,Bertoldi G..,Premier V..,Callegari M..,Brida C..,...&Notarnicola C..(2020).Use of Sentinel-1 radar observations to evaluate snowmelt dynamics in alpine regions.Cryosphere,14(3).
MLA	Marin C.,et al."Use of Sentinel-1 radar observations to evaluate snowmelt dynamics in alpine regions".Cryosphere 14.3(2020).