Depletion of perennial sea ice in the East Arctic Ocean

Abstract
The extent of perennial sea ice in the East Arctic Ocean (0–180°E) decreased by nearly one half with an abrupt reduction of 0.95 × 106 km2, while the West Arctic Ocean (0–180°W) had a slight gain of 0.23 × 106 km2 between 2004 and 2005, as observed by satellite scatterometer data during November–December. The net decrease in the total perennial ice extent is 0.72 × 106 km2, about the size of Texas. Perennial ice in the East Arctic Ocean continued to be depleted with an areal reduction of 70% from October 2005 to April 2006. With the East Arctic Ocean dominated by seasonal sea ice, a strong summer melt may open a vast ice‐free region with a possible record minimum ice extent largely confined to the West Arctic Ocean. Simultaneous scatterometer measurements of sea ice and winds will be crucial for sea ice monitoring and forecasts.