Premium
The Potential Use of Synthetic Aperture Radar for Estimating Methane Ebullition From Arctic Lakes 1
Author(s) -
Walter Katey M.,
Engram Melanie,
Duguay Claude R.,
Jeffries Martin O.,
Chapin F.S.
Publication year - 2008
Publication title -
jawra journal of the american water resources association
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.957
H-Index - 105
eISSN - 1752-1688
pISSN - 1093-474X
DOI - 10.1111/j.1752-1688.2007.00163.x
Subject(s) - tundra , arctic , thermokarst , environmental science , methane , permafrost , snow , atmosphere (unit) , physical geography , greenhouse gas , atmospheric sciences , hydrology (agriculture) , oceanography , geology , ecology , geomorphology , meteorology , geography , geotechnical engineering , biology
Arctic lakes are significant emitters of methane (CH 4 ), a potent greenhouse gas, to the atmosphere; yet no rigorous quantification of the magnitude and variability of pan‐Arctic lake emissions exists. In this study, we demonstrate the potential for a new method using synthetic aperture radar (SAR) imagery to detect methane bubbles in lake ice to scale up whole‐lake measurements of CH 4 ebullition (bubbling) to regional scales. We estimated ebullition from lakes, which is often the dominant mode of lake emissions, by mapping the distribution of bubble clusters frozen in early winter ice across surfaces of seven tundra lakes and one boreal forest lake in Alaska. Applying previously measured ebullition rates associated with four distinct classes of bubble clusters found in lake ice, we estimated whole‐lake emissions from individual lakes. The percent surface area of lake ice covered with bubbles ( R 2 = 0.68) and CH 4 ebullition rates from lakes ( R 2 = 0.59) and were correlated with radar return values from RADARSAT‐1 Standard Beam mode 3 for the tundra lakes, suggesting that with appropriate scaling and consideration for variability in lake‐ice conditions, this technique has the potential to be used for estimating broader‐scale regional and pan‐Arctic lake methane emissions.