气候变化领域集成服务门户(CCPortal): The Antarctic sea ice cover from ICESat-2 and CryoSat-2: Freeboard, snow depth, and ice thickness

CCPortal

DOI	10.5194/tc-14-4453-2020
	The Antarctic sea ice cover from ICESat-2 and CryoSat-2: Freeboard, snow depth, and ice thickness
	Kacimi S.; Kwok R.
发表日期	2020
ISSN	19940416
起始页码	4453
结束页码	4474
卷号	14 期号:12
英文摘要	We offer a view of the Antarctic sea ice cover from lidar (ICESat-2) and radar (CryoSat-2) altimetry, with retrievals of freeboard, snow depth, and ice thickness that span an 8-month winter between 1 April and 16 November 2019. Snow depths are from freeboard differences. The multiyear ice observed in the West Weddell sector is the thickest, with a mean sector thickness m. The thinnest ice is found near polynyas (Ross Sea and Ronne Ice Shelf) where new ice areas are exported seaward and entrained in the surrounding ice cover. For all months, the results suggest that 1/4 65% 70% of the total freeboard is comprised of snow. The remarkable mechanical convergence in coastal Amundsen Sea, associated with onshore winds, was captured by ICESat-2 and CryoSat-2. We observe a corresponding correlated increase in freeboards, snow depth, and ice thickness. While the spatial patterns in the freeboard, snow depth, and thickness composites are as expected, the observed seasonality in these variables is rather weak. This most likely results from competing processes (snowfall, snow redistribution, snow and ice formation, ice deformation, and basal growth and melt) that contribute to uncorrelated changes in the total and radar freeboards. Evidence points to biases in CryoSat-2 estimates of ice freeboard of at least a few centimeters from high salinity snow (10) in the basal layer resulting in lower or higher snow depth and ice thickness retrievals, although the extent of these areas cannot be established in the current data set. Adjusting CryoSat-2 freeboards by 3-6 cm gives a circumpolar ice volume of 17 900-15 600 3 in October, for an average thickness of 1/4 1.29-1.13 m. Validation of Antarctic sea ice parameters remains a challenge, as there are no seasonally and regionally diverse data sets that could be used to assess these large-scale satellite retrievals. © Author(s) 2020. This work is distributed under the Creative Commons Attribution 4.0 License.
英文关键词	continental freeboard; CryoSat; ice cover; ice thickness; ICESat; satellite altimetry; seasonality; snow cover; wind field; Amundsen Sea; Antarctic Ice Sheet; Antarctica; Ross Sea; Southern Ocean; Weddell Sea
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/202123
作者单位	Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, United States; Applied Physics Laboratory, Polar Science Center, University of Washington, Seattle, WA, United States
推荐引用方式 GB/T 7714	Kacimi S.,Kwok R.. The Antarctic sea ice cover from ICESat-2 and CryoSat-2: Freeboard, snow depth, and ice thickness[J],2020,14(12).
APA	Kacimi S.,&Kwok R..(2020).The Antarctic sea ice cover from ICESat-2 and CryoSat-2: Freeboard, snow depth, and ice thickness.Cryosphere,14(12).
MLA	Kacimi S.,et al."The Antarctic sea ice cover from ICESat-2 and CryoSat-2: Freeboard, snow depth, and ice thickness".Cryosphere 14.12(2020).