NSIDC has announced the discovery and recovery of space footage of Earth’s polar icecaps, dating back to 1964.
The recovered photographs have yielded some startling surprises, according to David Gallaher, technical services manager at NSIDC, bold mine:
In the Arctic, sea ice extent was larger in the 1960s than it is these days, on average. “It was colder, so we expected that,” Gallaher said. What the researchers didn’t expect were “enormous holes” in the sea ice, currently under investigation. “We can’t explain them yet,” Gallaher said.
“And the Antarctic blew us away,” he said. In 1964, sea ice extent in the Antarctic was the largest ever recorded, according to Nimbus image analysis. Two years later, there was a record low for sea ice in the Antarctic, and in 1969 Nimbus imagery, sea ice appears to have reached its maximum extent earliest on record.
When NASA launched Nimbus-1 50 years ago, the agency’s key goals were to test instruments that could capture images of clouds and other meteorological features, Gallaher said.
The Nimbus satellites dished up such excellent observations, NASA eventually handed over key technologies to the National Oceanic and Atmospheric Administration (NOAA), for use in weather forecasting, including hurricane forecasts.
But even with such success, data tapes and film that recorded Nimbus observations slipped through the cracks.
“At the time, the satellites’ real-time observations, including clouds, for example, were what people wanted most of all, for weather forecasting,” Gallaher said.
He and colleagues with NASA Goddard Space Flight Center in Greenbelt, Maryland, tracked down old Nimbus film to a NOAA facility in Suitland Maryland, where they were stored for about 25 years, and then Asheville, North Carolina. There, hundreds of 35-millimeter film reels lay in an old storage facility.
With funding from NASA, the researchers located and made operational an old film reader that could digitize the images. The team figured out how to determine geographic location for each image, given the orbit of the satellite. And they’ve now made more than 250,000 images public.
Source: NSIDC press release. h/t to Eric Worrall
Note: I attempted to look at the files myself, and discoverd that the vidicon imagery is stored in Hierarchical Data Format (.hdf). If anyone wants to make use of it, they’ll need a viewer, which can be obtained here: http://www.hdfgroup.org/products/java/hdfview/index.html