气候变化领域集成服务门户(CCPortal): Impact of assimilating a merged sea-ice thickness from CryoSat-2 and SMOS in the Arctic reanalysis

CCPortal

DOI	10.5194/tc-12-3671-2018
	Impact of assimilating a merged sea-ice thickness from CryoSat-2 and SMOS in the Arctic reanalysis
	Xie J.; Counillon F.; Bertino L.
发表日期	2018
ISSN	19940416
卷号	12 期号:11
英文摘要	Accurately forecasting the sea-ice thickness (SIT) in the Arctic is a major challenge. The new SIT product (referred to as CS2SMOS) merges measurements from the CryoSat-2 and SMOS satellites on a weekly basis during the winter. The impact of assimilating CS2SMOS data is tested for the TOPAZ4 system - the Arctic component of the Copernicus Marine Environment Monitoring Services (CMEMS). TOPAZ4 currently assimilates a large set of ocean and sea-ice observations with the Deterministic Ensemble Kalman Filter (DEnKF). Two parallel reanalyses are conducted without (Official run) and with (Test run) assimilation of CS2SMOS data from 19 March 2014 to 31 March 2015. Since only mapping errors were provided in the CS2SMOS observation, an arbitrary term was added to compensate for the missing errors, but was found a posteriori too large. The SIT bias (too thin) is reduced from 16 to 5&cm and the standard errors decrease from 53 to 38&cm (by 28&%) when compared to the assimilated SIT. When compared to independent SIT observations, the error reduction is 24&% against the ice mass balance (IMB) buoy 2013F and by 12.5&% against SIT data from the IceBridge campaigns. The improvement of sea-ice volume persists through the summer months in the absence of CS2SMOS data. Comparisons to sea-ice drift from the satellites show that dynamical adjustments reduce the drift errors around the North Pole by about 8&%-9&% in December 2014 and February 2015. Finally, using the degrees of freedom for signal (DFS), we find that CS2SMOS makes the prime source of information in the central Arctic and in the Kara Sea. We therefore recommend the assimilation of C2SMOS for Arctic reanalyses in order to improve the ice thickness and the ice drift. © 2018 Copernicus GmbH. All rights reserved.
学科领域	CryoSat; error analysis; forecasting method; ice thickness; Kalman filter; mass balance; satellite altimetry; sea ice; SMOS; Arctic; Arctic Ocean; Kara Sea; North Pole
语种	英语
scopus关键词	CryoSat; error analysis; forecasting method; ice thickness; Kalman filter; mass balance; satellite altimetry; sea ice; SMOS; Arctic; Arctic Ocean; Kara Sea; North Pole
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/119026
作者单位	Nansen Environmental and Remote Sensing Center, Bergen, N5006, Norway; Bjerknes Center for Climate Research, Bergen, Norway
推荐引用方式 GB/T 7714	Xie J.,Counillon F.,Bertino L.. Impact of assimilating a merged sea-ice thickness from CryoSat-2 and SMOS in the Arctic reanalysis[J],2018,12(11).
APA	Xie J.,Counillon F.,&Bertino L..(2018).Impact of assimilating a merged sea-ice thickness from CryoSat-2 and SMOS in the Arctic reanalysis.Cryosphere,12(11).
MLA	Xie J.,et al."Impact of assimilating a merged sea-ice thickness from CryoSat-2 and SMOS in the Arctic reanalysis".Cryosphere 12.11(2018).