In the central Arctic, summer starts, depending on latitude, in May and lasts until late August or early September, with solar radiation warming the air and sea ice. The sea ice cover acts as "a protective shield against the incoming solar radiation because of its high albedo”.  Changes in ice extent, thickness, or reflectivity greatly affect the Arctic's energy balance. The presence of melt ponds on Arctic summer sea, forming when ice melts, decrease reflectivity, accelerating ice melt in a feedback loop. 

Large-scale observations of melt pond coverage and sea ice albedo are essential to better understand the role of sea ice for Arctic amplification and improve its representation in global climate models. Niehaus et al, present a new algorithm combined to field observations of spectral albedo. This physical algorithm detects melt ponds on sea ice, the fraction of open ocean, and surface albedo in the Arctic summer.

It offers significant potential for enhancing global climate models and gaining a deeper understanding of Arctic climate changes.

Data is available from www.seaice.uni-bremen.de/melt-ponds   

Niehaus, H., Istomina, L., Nicolaus, M., Tao, R., Malinka, A., Zege, E., and Spreen, G.: Melt pond fractions on Arctic summer sea ice retrieved from Sentinel-3 satellite data with a constrained physical forward model, The Cryosphere, 18, 933–956, https://doi.org/10.5194/tc-18-933-2024 , 2024.