This shows magnitude trends for (left) spring sea-ice concentration (%) (as represented by trends from the climatological 50% sea-ice concentration level) and (left) annual MaxNDVI (unitless). The right panel shows land-surface summer warmth index (SWI) (˚C month). Trends were calculated using a least squares fit (regression) at each pixel. The SWI is the annual sum of the monthly mean temperatures > 0°C, derived from AVHRR thermal channels 3 (3.5.9 μm), 4 (10.3.3 μm) and 5 (11.5.5 μm). The total trend magnitude (regression times 30 years) over the 1982 period is presented.