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Algae Drive Enhanced Darkening of Bare Ice on the Greenland Ice Sheet
Author(s) -
Stibal Marek,
Box Jason E.,
Cameron Karen A.,
Langen Peter L.,
Yallop Marian L.,
Mottram Ruth H.,
Khan Alia L.,
Molotch Noah P.,
Chrismas Nathan A. M.,
Calì Quaglia Filippo,
Remias Daniel,
Smeets C. J. P. Paul,
Broeke Michiel R.,
Ryan Jonathan C.,
Hubbard Alun,
Tranter Martyn,
As Dirk,
Ahlstrøm Andreas P.
Publication year - 2017
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1002/2017gl075958
Subject(s) - greenland ice sheet , ice sheet , albedo (alchemy) , algae , sea ice , cryosphere , environmental science , geology , atmospheric sciences , oceanography , ecology , biology , art , performance art , art history
Surface ablation of the Greenland ice sheet is amplified by surface darkening caused by light‐absorbing impurities such as mineral dust, black carbon, and pigmented microbial cells. We present the first quantitative assessment of the microbial contribution to the ice sheet surface darkening, based on field measurements of surface reflectance and concentrations of light‐absorbing impurities, including pigmented algae, during the 2014 melt season in the southwestern part of the ice sheet. The impact of algae on bare ice darkening in the study area was greater than that of nonalgal impurities and yielded a net albedo reduction of 0.038 ± 0.0035 for each algal population doubling. We argue that algal growth is a crucial control of bare ice darkening, and incorporating the algal darkening effect will improve mass balance and sea level projections of the Greenland ice sheet and ice masses elsewhere.