Publications

Xiong, C; Ren, Y (2023). Arctic sea ice melt pond fraction in 2000-2021 derived by dynamic pixel spectral unmixing of MODIS images. ISPRS JOURNAL OF PHOTOGRAMMETRY AND REMOTE SENSING, 197, 181-198.

Abstract
The Arctic has experienced extensive sea ice retreat in recent decades, as observed from satellite remote sensing and simulated by general circulation models. The significant low albedo of melt pond compared with snow and ice results in more absorption of radiation compared with sea ice without melt pond, which will then enhance sea ice melt to form more melt pond. This so-called positive feedback of melt pond is crucial for sea ice thermal and physical properties. The melt pond coverage varies significantly spatially and temporally and satellite remote sensing provides a possible solution in determining the spatial coverage of melt pond. This work aims to develop a new physically based algorithm for retrieving the cover fraction of melt ponds on sea ice using remote sensing data. In the newly developed algorithm, dynamic sea ice and melt pond reflectances are used in the pixel spectral unmixing for melt pond fraction (MPF) estimation. Radiative transfer models for sea ice and melt pond reflec-tance modeling are developed for MPF retrieval algorithm. The validation of retrieved MPF and its comparison with static pixel spectral unmixing results show that the dynamic algorithm proposed in this study has the po-tential of application in wide range of situations by considering dynamic spectral reflectances of melt pond and sea ice. The Arctic MPF and sea ice cover fraction (SIF) in 2000-2021 are generated by applying the proposed algorithm. The spatial and temporal characteristics of MPF and SIF are analyzed. Time series trend analysis of MPF in 2000-2021 reveals the significant increasing trend of relative MPF in the Arctic. The melt pond expansion in 2000-2021 is more obvious in the marginal areas, especially the marginal areas close to Russia coast. Trend analysis for typical regions such as Beaufort Sea, Greenland Sea, the Baffin Bay, Chukchi, East Siberian, Laptev, and Kara seas and center Arctic also reveals that the relative MPF and SIF show contrasting trend.

DOI:
10.1016/j.isprsjprs.2023.01.023

ISSN:
1872-8235