Figure 2. Changes in the ice season annual duration at three north-to-south sites (Anvers-Palmer, Adelaide-Rothera, and Charcot Island) along the
western Antarctic Peninsula (Figure 1). The ice season has become shorter over the period from 1979 to 2012 (bottom to top), with trends toward
a later autumn sea ice advance (left) and earlier spring sea ice retreat (right). Sea ice cover is derived from Scanning Multichannel Microwave
Radiometer–Special Sensor Microwave/Imager (SMMR-SSM/I) data, as described in Stammerjohn et al. (2008a).