Surface meltwater runoff on the Greenland ice sheet estimated from remotely sensed supraglacial lake infilling rate

REMOTE SENSING OF ENVIRONMENT

卷:234

Article

Yang, Kang^1,2  Smith, Laurence C.^3,4,5  Fettweis, Xavier⁶  Gleason, Colin J.⁷  Lu, Yao^1,2  Li, Manchun^1,2 

[1] Nanjing Univ, Sch Geog & Ocean Sci, Nanjing 210023, Jiangsu, Peoples R China

[2] Jiangsu Prov Key Lab Geog Informat Sci & Technol, Nanjing 210023, Jiangsu, Peoples R China

[3] Brown Univ, Inst Brown Environm & Soc, Providence, RI 02912 USA

[4] Brown Univ, Dept Earth Environm & Planetary Sci, Providence, RI 02912 USA

[5] Univ Calif Los Angeles, Dept Geog, Los Angeles, CA 90095 USA

[6] Univ Liege, Dept Geog, B-4000 Liege, Belgium

[7] Univ Massachusetts, Dept Civil & Environm Engn, Amherst, MA 01002 USA

关键词: Surface runoff;    Surface mass balance;    Supraglacial lake;    ArcticDEM;    Greenland ice sheet;   

DOI  :  10.1016/j.rse.2019.111459

来源: Elsevier

【 摘 要 】

Surface runoff constitutes a large percentage of Greenland Ice Sheet (GrIS) mass loss at present but is difficult to measure directly. This study provides a novel method to estimate surface runoff through remote sensing of supraglacial lake volumes. Because terminal, non-draining (consistently expanding during the melt season) lakes impound runoff from their surrounding contributing catchments, such changes reflect runoff produced within the catchment. To estimate supraglacial lake volumes, multi-temporal lake maps derived from Landsat-8 images are intersected with dry lake-bed topographic depressions (showing lake bathymetry) identified for two supraglacial catchments (similar to 10 km(2)) in southwestern GrIS, using high-resolution (2 m) ArcticDEMs. Intersecting remotely sensed lake shorelines with their underlying ice surface topography yields multi-temporal lake volume changes, which are then compared with cumulative runoff as simulated by four Surface Mass Balance (SMB) models (HIRHAM5, MAR3.6, RACMO2.3, and MERRA-2). Comparison of cumulative lake infilling with SMB simulations for these two lakes over the period 8-31 July 2015 indicates that SMB models overestimated surface runoff by 106 - 123%. These large offsets improved after early July, overestimating runoff by 40 - 55%. The runoff delay function incorporated into the MAR3.6 model improves simulation of early melt season runoff, signifying the importance of integrating meltwater routing schemes into SMB models for improved understanding of Greenland supraglacial hydrology and surface mass balance.

【 授权许可】

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