But officials said the flights also will serve as a partial replacement for one satellite: NASA's Ice, Cloud and Land Elevation Satellite, known as ICESat.

CNN: NASA flights will study Antarctic ice changes

Less ice on rivers, lakes and the sea will lead to more evaporation, probably increasing cloud cover at mid-levels, which should have a cooling effect.

ECONOMIST: The science

In China, they use artillery shells, rockets and airplanes to spray existing cloud systems with silver iodide, a compound that triggers moisture in the clouds to form ice crystals, which then fall to earth as snow or rain.

WSJ: Blizzard Renews Storm Over China Making Snow

"Patchy ice is possible to start New Year's Day but it is generally drier with variable amounts of cloud and plenty of sunny spells developing, " she said.

BBC: Weather in Wales improving after flooding on Monday