Long time series (1984–2020) of albedo variations on the Greenland ice sheet from harmonized Landsat and Sentinel 2 imagery ...

• Main Authors: Feng, Shunan, Cook, Joseph Mitchell, Anesio, Alexandre Magno, Benning, Liane. G. G., Tranter, Martyn
• Format: Text
• Language: unknown
• Published: Freie Universität Berlin 2023
• Subjects: Arctic glaciology; albedo; data harmonization; snow/ice surface processes; 500 Naturwissenschaften und Mathematik550 Geowissenschaften, Geologie550 Geowissenschaften; Arctic; Greenland; Ice Sheet
• Online Access: https://dx.doi.org/10.17169/refubium-39258; https://refubium.fu-berlin.de/handle/fub188/39540

Albedo is a key factor in modulating the absorption of solar radiation on ice surfaces. Satellite measurements have shown a general reduction in albedo across the Greenland ice sheet over the past few decades, particularly along the western margin of the ice sheet, a region known as the Dark Zone (albedo < 0.45). Here we chose a combination of Landsat 4–8 and Sentinel 2 imagery to enable us to derive the longest record of albedo variations in the Dark Zone, running from 1984 to 2020. We developed a simple, pragmatic and efficient sensor transformation to provide a long time series of consistent, harmonized satellite imagery. Narrow to broadband conversion algorithms were developed from regression models of harmonized satellite data and in situ albedo from the Program for Monitoring of the Greenland Ice Sheet (PROMICE) automatic weather stations. The albedo derived from the harmonized Landsat and Sentinel 2 data shows that the maximum extent of the Dark Zone expanded rapidly between 2005 and 2007, ...