Kohnen-Thermometry 2023/2024

Expedition to the East Antarctic Plateau to determine local warming trends based on Borehole Temperatures

This austral summer (December 2023 – January 2024), an expedition went to the AWI station “Kohnen”, which is sited at nearly 3000 m height on the plateau of East Antarctica. With 12 people, we worked several weeks at temperatures of below -20 degrees, enjoying the bright polar day and an endless ice horizon.

The goals of the expedition were to measure vertical temperatures profiles in boreholes to reconstruct climate changes of the past century, to test hypothesis concerning non-climate variations in ice-core records and to prepare and test new sampling and measurement devices for Traverse expeditions in the following years.

We successfully reopened six boreholes with depths of down to 200m within a 50 km area and installed a high-precision (< 1 mK) borehole temperature logging winch system, developed at AWI, which will provide a solid basis to determine recent warming trends on the East Antarctic Plateau with respect to the past.

We also developed and installed measurement chains in boreholes. They will measure daily borehole temperatures for the next several years, which will enable us to assess seasonal cycles, temporal fluctuations and uncertainties. These chains will further enable borehole measurements in remote new ice core locations in future expeditions and thus a larger coverage of borehole temperature measurements across the plateau of Antarctica.