Observation bias correction reveals more rapidly draining lakes on the Greenland Ice Sheet ...

Rapid drainage of supraglacial lakes on the Greenland Ice Sheet enables the establishment of surface-to-bed hydrologic connections and subsequent basal water delivery. Estimates of the number and spatial distribution of rapidly draining lakes vary widely, and no study has quantified the impact of ob...

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Bibliographic Details
Main Authors: Christoffersen, P, Cooley, S
Format: Article in Journal/Newspaper
Language:English
Published: Wiley 2017
Subjects:
Online Access:https://dx.doi.org/10.17863/cam.15840
https://www.repository.cam.ac.uk/handle/1810/269630
Description
Summary:Rapid drainage of supraglacial lakes on the Greenland Ice Sheet enables the establishment of surface-to-bed hydrologic connections and subsequent basal water delivery. Estimates of the number and spatial distribution of rapidly draining lakes vary widely, and no study has quantified the impact of observation bias due to cloud cover in satellite imagery on reported frequency of rapid lake drainage. To better understand the rapid drainage mechanism, we map and track an average of 515 supraglacial lakes per year in central West Greenland from 2000-2015. We test four previously published definitions of rapid lake drainage and find the proportion of rapidly draining lakes to vary from 3% to 38% and to be strongly dependent on observation frequency. We then apply an observation bias correction and test three new drainage criteria, which reveal a bias corrected rapid drainage probability of 36-45%. When observation bias is addressed, we can also show that lakes above 1600m are as likely to drain rapidly as lakes ...