Peeping at Polynyas
Polynyas—expanses of open water in the Antarctic Ocean surrounded by ice or land—might not spur the interest of polar bears, penguins or even most people but en masse they do have the capacity to impact atmospheric and climatic conditions in the southern polar region.
To investigate these impacts CIRES Fellow John Cassano and a team of researchers visited Antarctica for the tenth time this August—a highly successful trip which shed more light on the formation and consequences of the Terra Nova Bay and Ross Sea polynyas.
During the Antarctic winter cold air from the interior of the continent blows out over Terra Nova Bay and when sea ice is present the sea ice acts like a blanket over the ocean stopping the overlying cold, dry air from removing ocean heat and moisture. If the winds blowing off of the continent are strong enough however, the sea ice near the coast gets blown out to sea leaving an area of open water right along the coast creating the Terra Nova Bay polynya.
The researchers used unmanned aircraft systems (UAS) to make detailed observations of the air-sea interactions in the Terra Nova Bay polynya, which is surrounded by a combination of sea ice and land. Digital cameras mounted on the Aerosonde unmanned aircraft vehicles took photos of the ice and ocean as the UAVs flew at heights as low as 300feet above the surface of the ocean.
Near the end of their expedition the scientists flew over the Ross Sea polynya, just east of Ross Island. With this flight the scientists collected the first 3-dimensional atmospheric data of a major Antarctic weather pattern known as the Ross Ice Shelf airstream.