Dropsonde observations were made by the U.S. Air Force along the "Ptarmigan" track of its reconnaissance program. This track was mainly over the Beaufort Sea and the western Arctic Ocean. Vertical profiles of geopotential height, temperature, and dew point temperature at various pressure levels are available for eleven years between 1950 and 1961 (excluding 1953) for the lower troposphere mainly below 500mb.

In comparing the locations on the dropsondes to the locations on the aircraft reconnaissance reports in ds360.0, DSS found that the dropsonde longitudes are off by 10 degrees. For dropsondes over the Western Hemisphere, the positions are 10 degrees east of the aircraft positions, and for the Eastern Hemisphere, they are 10 degrees west of the aircraft position.