Sea ice extent and concentration [in 'State of the Climate in 2007']

Antarctic sea ice in 2007 was characterized by considerable temporal and spatial variability, with ice extent anomalies ranging from a record low in May of –12% or –1.2 × 10⁶ km² (equal to 1980) to a record high in December of +14% or +1.7 × 10⁶ km² for the satellite time series (1978–present; Fig. 5.26). The analysis is based on monthly mean SSM/I-derived sea ice concentration data produced by the NSIDC Sea Ice Index project (Fetterer et al. 2002, updated monthly).