Ultralow Surface Temperatures in East Antarctica From Satellite Thermal Infrared Mapping: The Coldest Places on Earth

• Main Authors: Scambos, T. A., Campbell, G. G., Pope, A., Haran, T., Muto, A., Lazzara, M., Reijmer, C. H., van den Broeke, M. R.
• Other Authors: Sub Dynamics Meteorology, Marine and Atmospheric Research
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2018
• Subjects: air temperature inversion; Antarctica; remote sensing; snow and ice; surface temperature; thermal mapping; Geophysics; Earth and Planetary Sciences(all); Antarctic; East Antarctica; Antarc*
• Online Access: https://dspace.library.uu.nl/handle/1874/367883

We identify areas near the East Antarctic ice divide where <−90 °C surface snow temperatures are observed in wintertime satellite thermal-band data under clear-sky conditions. The lowest temperatures are found in small (<200 km2) topographic basins of ~2 m depth above 3,800 m elevation. Approximately 100 sites have observed minimum surface temperatures of ~−98 °C during the winters of 2004–2016. Comparisons of surface snow temperatures with near-surface air temperatures at nearby weather stations indicate that ~−98 °C surfaces imply ~−94 ± 4 °C 2-m air temperatures. Landsat 8 thermal band data and elevation data show gradients near the topographic depressions of ~6 °C km−1 horizontally and ~4 °C m−1 vertically. Ultralow temperature occurrences correlate with strong polar vortex circulation. We discuss a conceptual model of radiative surface cooling that produces an extreme inversion layer. Further cooling occurs as near-surface cold air pools in shallow high-elevation topographic basins, moderated by clear-air downwelling radiation and heat from subsurface snow.