气候变化领域集成服务门户(CCPortal): Tidal Modulation of Buoyant Flow and Basal Melt Beneath Petermann Gletscher Ice Shelf, Greenland

CCPortal

DOI	10.1029/2020JC016427
	Tidal Modulation of Buoyant Flow and Basal Melt Beneath Petermann Gletscher Ice Shelf, Greenland
	Washam P.; Nicholls K.W.; Münchow A.; Padman L.
发表日期	2020
ISSN	21699275
卷号	125 期号:10
英文摘要	A set of collocated, in situ oceanographic and glaciological measurements from Petermann Gletscher Ice Shelf, Greenland, provides insights into the dynamics of under-ice flow driving basal melting. At a site 16 km seaward of the grounding line within a longitudinal basal channel, two conductivity-temperature (CT) sensors beneath the ice base and a phase-sensitive radar on the ice surface were used to monitor the coupled ice shelf-ocean system. A 6 month time series spanning 23 August 2015 to 12 February 2016 exhibited two distinct periods of ice-ocean interactions. Between August and December, radar-derived basal melt rates featured fortnightly peaks of ∼15 m yr−1 which preceded the arrival of cold and fresh pulses in the ocean that had high concentrations of subglacial runoff and glacial meltwater. Estimated current speeds reached 0.20 – 0.40 m s−1 during these pulses, consistent with a strengthened meltwater plume from freshwater enrichment. Such signals did not occur between December and February, when ice-ocean interactions instead varied at principal diurnal and semidiurnal tidal frequencies, and lower melt rates and current speeds prevailed. A combination of estimated current speeds and meltwater concentrations from the two CT sensors yields estimates of subglacial runoff and glacial meltwater volume fluxes that vary between 10 and 80 m3 s−1 during the ocean pulses. Area-average upstream ice shelf melt rates from these fluxes are up to 170 m yr−1, revealing that these strengthened plumes had already driven their most intense melting before arriving at the study site. ©2020. The Authors.
英文关键词	basal melt; boundary layer; glacier; Greenland; ice shelves; ice-ocean interactions
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/186651
作者单位	School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, GA, United States; College of Earth, Ocean, and Environment, University of Delaware, Newark, DE, United States; British Antarctic Survey, Natural Environment Research Council, Cambridge, United Kingdom; Earth & Space Research, Corvallis, OR, United States
推荐引用方式 GB/T 7714	Washam P.,Nicholls K.W.,Münchow A.,et al. Tidal Modulation of Buoyant Flow and Basal Melt Beneath Petermann Gletscher Ice Shelf, Greenland[J],2020,125(10).
APA	Washam P.,Nicholls K.W.,Münchow A.,&Padman L..(2020).Tidal Modulation of Buoyant Flow and Basal Melt Beneath Petermann Gletscher Ice Shelf, Greenland.Journal of Geophysical Research: Oceans,125(10).
MLA	Washam P.,et al."Tidal Modulation of Buoyant Flow and Basal Melt Beneath Petermann Gletscher Ice Shelf, Greenland".Journal of Geophysical Research: Oceans 125.10(2020).