RAPID: Instrumentation, Calibration, and Field Work Planning for an Expedition to Antarctica's Lowest Temperature Site

Satellite measurements of the surface snow temperatures on the East Antarctic Plateau have identified an extensive area where mid-winter conditions are frequently below -90°C. A specialized surface observation station has been built and partially tested and is intended to link surface observations with the satellite data. The station is designed to measure surface conditions, including wind and blowing snow. These data will be transmitted during the Antarctic winter. The site will also be instrumented with two cold-rated automated weather stations (AWS). This RAPID award would specifically support the further development and calibration of the existing instrument suite, add an additional sensor (to measure wind and blowing snow), and test the station under realistic field conditions. The project would leverage the logistics of another Antarctic national program and outside, private providers to deploy these sensors. Ultimately, the dataset could lead to public interest, which could in turn provide opportunity to publicly discuss polar climate change. The goal of this RAPID is to establish the coldest temperature that can be reached on Earth’s surface to better understand the weather and climate controls on the lowest-temperature events. The site on the East Antarctic Plateau of the most frequent occurrence of <-98°C conditions is located ~100 km from the Pole of Inaccessibility. At roughly 100 smaller valley sites within this region (typically ~5 square km in area), surface snow temperatures can reach -98°C. Air temperatures at these sites at 2 m height are likely a few degrees above this value due to the intense near-surface gradients that form under clear-sky conditions during polar night, and are estimated to be -94 ± 2°C. The recognized lowest surface air temperature record is -89.2°C, measured at Vostok Station in July 1983. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.