Climate Fact: Antarctica's Moisture Sources
Once water is evaporated from the ocean or a moist land surface, it may spend days traveling through the air. Complicated systems of winds at different levels of the atmosphere can transport moisture (as well as other gases and dust) from the point of origin to remote locations thousands of miles away. While about 30 percent of the moisture that rains or snows over Antarctica originates in the Southern Ocean close to the continent, the rest comes from latitudes north of 50 degrees South (about the same latitude as the southern tip of New Zealand). Ten percent comes from north of 30 degrees South (about the same latitude as Durban, South Africa). The higher elevations closer to the center of Antarctica have mean moisture origin sources north of 44 degrees South. During the summer, when there is less sea ice, more of Antarctica’s precipitation originates from the waters around the continent.
Seasons: Winter, Spring, Summer, Fall
Source: Sodemann, H and Stohl, A. “Asymmetries in the moisture origin of Antarctic precipitation.” Geophysical Research Letters 36 (2009): L22803.
