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A new study published in the journal Geophysical Research Letters shows that the analysis of satellite data shows that the valleys in the Antarctic ice sheets can reach close to -100 ºC . This is significantly lower than the record of – 93 degrees Celsius observed in the same area.
The scientists reached this new data after analyzing again the readings of the Earth observation satellites . In 2013, a team of scientists from the National Snow and Ice Data Center of the University of Colorado Boulder (USA) announced that they had found surface temperatures of -93ºC in several points of the Eastern Antarctic Plateau ; Now, by recalibrating these readings with updated data from meteorological stations in the field, they have discovered that the colder sites are actually much colder than previously thought: they reach -98ºC.
These temperatures are observed during the night of the South Pole and “seem to be as low as it is possible to reach,” 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 are produced: to reach this low point, not only are clear skies necessary , but the air must also be extremely dry, because any water vapor in the air tends to to warm it, although slightly.
The scientists analyzed data from NASA’s Terra and Aqua satellites, in addition to NOAA’s Polar environmental satellites (National Oceanic and Atmospheric Administration’s), recorded between 2004 and 2016. The greatest temperature drops occur during the night during the winter in the southern hemisphere , which correspond to the months of June, July and August.
The researchers claim that the temperature could drop further, although it would take an unusual amount of clear skies and dry air to get it.
They found dozens of places 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 does not break in a long, long time.
The increase of carbon dioxide levels in the atmosphere and the high levels of water vapor as a result, represents that the conditions necessary for super cold temperatures are increasingly rare.
“Radioactive processes that control the low surface temperatures and air, and the changing composition of the atmosphere mean that in the future we see fewer events extremely extreme temperatures,” the authors write.