Depletion of perennial sea ice in the East Arctic Ocean

The extent of perennial sea ice in the East Arctic Ocean ( 0 - 180 degrees E) decreased by nearly one half with an abrupt reduction of 0.95 x 10(6) km(2), while the West Arctic Ocean (0 - 180 degrees W) had a slight gain of 0.23 x 10(6) km(2) 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 x 10(6) km(2), 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.