Despite a run-in with an iceberg and the world’s worst sailing conditions, Saildrone 1020 successfully completed its 13,670-nautical-mile journey around Antarctica, and indicated that parts of the Southern Ocean emit carbon dioxide in winter.
Antarctic sea ice extent hit a record low extent in February, but thanks to large natural variability from year to year, experts say there is still no long-term trend.
Earth's coldest waters are warming, an indication that global warming has reached one of the most remote corners of the ocean's circulatory system.