TS-X images showing the transition of sea ice from winter to summer. A small section of TS-X SM images acquired on June 9 (winter), June 14 (surface melt), July 5 (after melt pond drainage) and July 29 (summer) at C1. In (a), the brightest tone (white) represents MYI, the darker tone (grey) indicates FYI, and the darkest tone (black) is open water. In (b), the backscattering intensity was reversed. The brightest tone represents open water (high backscatter from wind-roughened sea surface). The darker tone represents MYI, while the grey tone represents FYI and thin refrozen leads. In (c), the darkest tone is open water, and the brighter grey tone is FYI or used-to-be leads. Black spots on sea ice are melt ponds on MYI that survived the drainage. Scale bar is 1000 m; north is up in the image. DOI: https://doi.org/10.1525/elementa.232.f6