Remote sensing of ice albedo using harmonized Landsat and Sentinel 2 datasets: validation

Area of Science:

• Earth Science
• Remote Sensing
• Glaciology

Background:

• Albedo is crucial for regulating solar radiation absorption and meltwater production on ice surfaces.
• Landsat and Sentinel 2 provide continuous medium-resolution Earth surface observations.
• A harmonized satellite albedo (HSA) product exists for the Greenland Ice Sheet.

Purpose of the Study:

• Validate the HSA product for Arctic and alpine glaciers and ice caps using in situ measurements.
• Determine the optimal spatial window size for point-to-pixel albedo analysis.
• Assess cross-sensor differences between Landsat 9 (L9) and Landsat 8 (L8) data.

Main Methods:

• Validation of the HSA product using in situ albedo measurements across diverse glaciers.
• Analysis of spatial window size impact on ice surface homogeneity and albedo validation using GLCM statistics.
• Cross-sensor comparison of L9 and L8 data for albedo product integration.

Main Results:

• The optimal spatial window size for albedo validation was determined to be 90m.
• HSA product showed strong agreement with in situ measurements (Pearson's R: 0.68–0.92) across various glacier types.
• Cross-sensor differences between L9 and L8 were found to be minor.

Conclusions:

• The HSA product is a reliable tool for albedo estimation on Arctic and alpine glaciers.
• A 90m spatial window is recommended for accurate albedo validation.
• Landsat 9 data can be seamlessly integrated into the HSA product without additional harmonization.