Leatherhead Matters

Bloomberg reports:

A glitch in satellite sensors caused scientists to underestimate the extent of Arctic sea ice by 500,000 square kilometers (193,000 square miles), a California- size area, the U.S. National Snow and Ice Data Center said.

The error, due to a problem called “sensor drift,” began in early January and caused a slowly growing underestimation of sea ice extent until mid-February. That’s when “puzzled readers” alerted the NSIDC about data showing ice-covered areas as stretches of open ocean, the Boulder, Colorado-based group said on its Web site.