A new study published in the journal Geophysical Research Letters shows that analysis of satellite data shows that valleys in the Antarctic ice sheets can reach close to -100 ° C. This is significantly lower than the record of -93 degrees Celsius observed in the same area.
The scientists reached this new data after analyzing the readings of the Earth observation satellites again. In 2013, a team of scientists from the National Snow and Ice Data Center at the University of Colorado Boulder (USA) announced they had found surface temperatures of -93ºC at various points on the East Antarctic Plateau ; Now, by recalibrating these readings with updated data taken from meteorological stations on the ground, they have discovered that the coldest places are actually much colder than previously believed: they reach -98ºC.
These temperatures are observed at night from the South Pole and “appear to be as low as possible,” according to the international team of researchers who worked on the study. These temperatures below zero are maintained up to 3 meters deep.
The new study of the data also yielded something interesting about how these record lows occur: Not only are clear skies necessary to reach this low point, but the air must also be extremely dry, because any water vapor in the air tends to to warm it up, albeit slightly.
The scientists analyzed data from NASA’s Terra and Aqua satellites, as well as NOAA’s (National Oceanic and Atmospheric Administration’s) Polar environmental satellites, recorded between 2004 and 2016. The largest drops in temperature occur at night during winter in the southern hemisphere , which correspond to the months of June, July and August.
The researchers say the temperature could drop even further, although it would take an unusual amount of clear skies and dry air to achieve this.
They found dozens of sites with such cold temperatures ; However, considering that the same temperature was recorded in several places along the glacier, even many hundreds of kilometers away, scientists believe that this could be the lowest temperature limit on Earth.
And it could be a record that won’t break for a long, long time.
Increasing levels of carbon dioxide in the atmosphere, and elevated levels of water vapor as a result, represent that the conditions necessary for super cold temperatures are increasingly rare.
“Radioactive processes that control low air and surface temperatures, and the changing composition of the atmosphere, mean that we may see fewer extremely extreme temperature events in the future,” the authors write.
Referencia: Ultra‐low surface temperatures in East Antarctica from satellite thermal infrared mapping: the coldest places on Earth. T. A. Scambos , G. G. Campbell , A. Pope, T. Haran , A. Muto, M. Lazzara, C. H. Reijmer, M. R. van den Broeke. Junio 2018. Geophysical Research Letters. DOI: https://doi.org/10.1029/2018GL078133
Image Credit: Ted Scambos / NSIDC and CU Boulder
