Near zero replenishment of the Arctic multiyear sea ice cover at the end of 2005 summer

Abstract

The remarkably low Arctic multiyear (MY) sea ice coverage following the summer of 2005 is placed in the context of its variability over the past seven years (2000–2006). Annual cycles of MY ice coverage, from QuikSCAT and satellite passive ice motion, show that the replenishment of MY ice area at the end of this summer is near zero (0.1 × 106 km2) compared to the previous five summers of 1.0, 1.2, 0.4, 0.4, and 0.9 × 106 km2. This is examined in terms of anomalies in ice export and the record of freezing (FDD) and melting degree‐days (MDD). The 2005 summer (Jun–Sep) saw the highest Fram Strait ice export (>0.25 × 106 km2) compared to the 7‐year mean of 0.14 × 106 km2. This directly explains ∼40% of the decrease in MY coverage of 0.6 × 106 km2 between Jan 2005 and Jan 2006. The cumulative effects of the recent warmer winters and summers, relative to the longer‐term record since 1958, explain the balance. For this short record, the combination of spatially averaged FDD and MDD anomalies of the preceding year explain ∼63% of the variance in the replenishment areas.