气候变化领域集成服务门户(CCPortal): Sea Ice Roughness Overlooked as a Key Source of Uncertainty in CryoSat-2 Ice Freeboard Retrievals

CCPortal

DOI	10.1029/2019JC015820
	Sea Ice Roughness Overlooked as a Key Source of Uncertainty in CryoSat-2 Ice Freeboard Retrievals
	Landy J.C.; Petty A.A.; Tsamados M.; Stroeve J.C.
发表日期	2020
ISSN	21699275
卷号	125 期号:5
英文摘要	ESA's CryoSat-2 has transformed the way we monitor Arctic sea ice, providing routine measurements of the ice thickness with near basin-wide coverage. Past studies have shown that uncertainties in the sea ice thickness retrievals can be introduced at several steps of the processing chain, for instance, in the estimation of snow depth, and snow and sea ice densities. Here, we apply a new physical model to CryoSat-2, which further reveals sea ice surface roughness as a key overlooked feature of the conventional retrieval process. High-resolution airborne observations demonstrate that snow and sea ice surface topography can be better characterized by a lognormal distribution, which varies based on the ice age and surface roughness within a CryoSat-2 footprint, than a Gaussian distribution. Based on these observations, we perform a set of simulations for the CryoSat-2 echo waveform over “virtual” sea ice surfaces with a range of roughness and radar backscattering configurations. By accounting for the variable roughness, our new lognormal retracker produces sea ice freeboards that compare well with those derived from NASA's Operation IceBridge airborne data and extends the capability of CryoSat-2 to profile the thinnest/smoothest sea ice and thickest/roughest ice. Our results indicate that the variable ice surface roughness contributes a systematic uncertainty in sea ice thickness of up to 20% over first-year ice and 30% over multiyear ice, representing one of the principal sources of pan-Arctic sea ice thickness uncertainty. © 2020. The Authors.
英文关键词	Arctic; CryoSat-2; Ice Freeboard; Numerical Modelling; Roughness; Sea Ice
语种	英语
来源期刊	Journal of Geophysical Research: Oceans
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/186872
作者单位	Bristol Glaciology Centre, School of Geographical Sciences, University of Bristol, Bristol, United Kingdom; Earth System Science Interdisciplinary Center, University of Maryland, College Park, MD, United States; Cryospheric Sciences Laboratory, NASA Goddard Space Flight Center, Greenbelt, MD, United States; Centre for Polar Observation and Modelling, Earth Sciences, University College London, London, United Kingdom; Centre for Earth Observation Science, University of Manitoba, Winnipeg, MB, Canada
推荐引用方式 GB/T 7714	Landy J.C.,Petty A.A.,Tsamados M.,et al. Sea Ice Roughness Overlooked as a Key Source of Uncertainty in CryoSat-2 Ice Freeboard Retrievals[J],2020,125(5).
APA	Landy J.C.,Petty A.A.,Tsamados M.,&Stroeve J.C..(2020).Sea Ice Roughness Overlooked as a Key Source of Uncertainty in CryoSat-2 Ice Freeboard Retrievals.Journal of Geophysical Research: Oceans,125(5).
MLA	Landy J.C.,et al."Sea Ice Roughness Overlooked as a Key Source of Uncertainty in CryoSat-2 Ice Freeboard Retrievals".Journal of Geophysical Research: Oceans 125.5(2020).