We investigate seasonal trends in sea ice concentration and the relative contributions of the Antarctic Oscillation (AAO), the Pacific-South American two modes (PSA1 and PSA2), and the El Niño-Southern Oscillation (ENSO). The summer range of the trend in the Antarctic sea ice is the largest, from... Show moreWe investigate seasonal trends in sea ice concentration and the relative contributions of the Antarctic Oscillation (AAO), the Pacific-South American two modes (PSA1 and PSA2), and the El Niño-Southern Oscillation (ENSO). The summer range of the trend in the Antarctic sea ice is the largest, from -83.8% to 59.6% per 29 yr over the period of 1979 through 2007, while the autumn range is the least, from -49.7% to 39.6% per 29 yr for the period of 1979 through 2007. In autumn, among the four indices the largest contribution to the trend in sea ice is the AAO; in winter the ENSO and the PSA1 are better than the other two indices; during spring and summer a change of more than 15% per 29 yr is associated with PSA1. No matter the season, the spatial pattern of the residual trend is similar to that of the total trend; moreover, the combined trends of the four indices only explains less than one-third of the total trend. Show less
