Validating Antarctic Pressure Reconstructions Using Historical Expedition Data

Antarctica may be one of Earth’s most complex climates, however it is not as well studied and understood as many other regions across Earth. A major challenge faced in understanding Antarctic climate is that climate-related records are temporally sparse. For example, Antarctic sea ice trends are largely unknown before 1979, prior to the continuous satellite record. To extend the relatively short observations, reconstructions of Antarctic climate have been created recently, including the Antarctic circumpolar westerly winds and pressure over the Antarctic continent; reconstructions of Antarctic sea ice extent and concentration are being developed. All successful reconstructions of pressure or sea ice require thorough evaluations. While this can be done in a traditional statistical sense, there is considerable value of comparing the data directly to any available observations that were withheld during reconstructions. For pressure reconstructions and sea ice reconstructions, one source of such comparison is historical data. These measurements come from ship records, whaling and sealing expeditions across the Southern Ocean, early Antarctic explorers, and other data archives. This work evaluates the existing pressure reconstructions with these discrete independent sources of historical data. This has helped to further determine the accuracy of these reconstructions and therefore aid in their utility by other researchers.