DOI: 10.5194/tc-10-2027-2016
Scopus记录号: 2-s2.0-84988029353
论文题名: Sea-ice indicators of polar bear habitat
作者: Stern H ; L ; , Laidre K ; L
刊名: Cryosphere
ISSN: 19940416
出版年: 2016
卷: 10, 期: 5 起始页码: 2027
结束页码: 2041
语种: 英语
英文关键词: arctic environment
; bear
; concentration (composition)
; environmental indicator
; habitat availability
; ice retreat
; microwave radiometer
; phenology
; satellite data
; sea ice
; subpopulation
; trend analysis
; Arctic Ocean
; Ursus maritimus
英文摘要: Nineteen subpopulations of polar bears (Ursus maritimus) are found throughout the circumpolar Arctic, and in all regions they depend on sea ice as a platform for traveling, hunting, and breeding. Therefore polar bear phenology - the cycle of biological events - is linked to the timing of sea-ice retreat in spring and advance in fall. We analyzed the dates of sea-ice retreat and advance in all 19 polar bear subpopulation regions from 1979 to 2014, using daily sea-ice concentration data from satellite passive microwave instruments. We define the dates of sea-ice retreat and advance in a region as the dates when the area of sea ice drops below a certain threshold (retreat) on its way to the summer minimum or rises above the threshold (advance) on its way to the winter maximum. The threshold is chosen to be halfway between the historical (1979-2014) mean September and mean March sea-ice areas. In all 19 regions there is a trend toward earlier sea-ice retreat and later sea-ice advance. Trends generally range from -3 to -9daysdecade-1 in spring and from +3 to +9daysdecade-1 in fall, with larger trends in the Barents Sea and central Arctic Basin. The trends are not sensitive to the threshold. We also calculated the number of days per year that the sea-ice area exceeded the threshold (termed ice-covered days) and the average sea-ice concentration from 1 June through 31 October. The number of ice-covered days is declining in all regions at the rate of -7 to -19daysdecade-1, with larger trends in the Barents Sea and central Arctic Basin. The June-October sea-ice concentration is declining in all regions at rates ranging from -1 to -9percentdecade-1. These sea-ice metrics (or indicators of habitat change) were designed to be useful for management agencies and for comparative purposes among subpopulations. We recommend that the National Climate Assessment include the timing of sea-ice retreat and advance in future reports. © Author(s) 2016. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/75082
Appears in Collections: 影响、适应和脆弱性 气候变化与战略
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作者单位: Polar Science Center, Applied Physics Laboratory, University of Washington, 1013 NE 40th Street, Seattle, WA, United States; Greenland Institute of Natural Resources, Nuuk, Greenland
Recommended Citation:
Stern H,L,, Laidre K,et al. Sea-ice indicators of polar bear habitat[J]. Cryosphere,2016-01-01,10(5)