Recent frigid air across the U.S. is like a heat wave compared to the unimaginable chill in Antarctica, where a NASA satellite sensed temperatures of -135.8°F and -135.3°F near eastern Antarctica’s Dome Argus in August 2010 and this past July.
Video overview of Antarctic temperature measurements from NASA
Headlines have touted these two readings as the coldest temperatures ever on Earth, surpassing the official record of -128.6°F from Vostok, Antarctica in July 1983. But these headlines are a little misleading.
The two readings near Dome Argus were taken by the Moderate Resolution Imaging Spectroradiometer (MODIS) and Advanced Very High Resolution Radiometer (AVHRR) instruments aboard NASA satellites, which detect the heat radiated off of the Earth’s surface and only estimate the temperature. They are not direct measurements.
The World Meteorological Organization (WMO) only accepts official temperature records taken by calibrated thermometers near the surface, making these two readings the coldest unofficially recorded.
“Satellite earth skin temperature measurements will never be accepted as ‘official’ weather observations no matter how accurate their data might be,” writes Christopher Burt, Wunderground’s weather historian.
Official or not, the satellite measurements reveal unmistakably frigid air, more characteristic of planet Mars. Local topography in the Dome Argus region and radiational cooling conspired to create these exceptionally cold circumstances.
NASA primer on how it gets so cold in Antarctica
Here’s how it gets so cold: The Earth’s surface cools off at night by radiating its heat out into space, cooling the layer of air immediately above the ground through conduction. This process is most effective when skies are clear, winds are calm and moisture is low, conditions that occur often in this part of Antarctica. NASA explains that this layer of very cold air at the surface “is denser than the relatively warmer air above it, which causes it to slide down the shallow slope of domes on the Antarctic plateau. As it flows into the pockets, it can be trapped, and the cooling continues.” The -135 to -136°F measurements were sensed in two of these pockets off the Dome Argus ridge.
But it’s a stretch to say these temperatures are records – even as sensed from satellite data.
“This is probably an unusual random reading in a place that hasn’t been measured much and could have been colder or hotter in the past,” University of Colorado scientist Waleed Abdalati told USA Today.
The -135 to -136 temperatures sensed in 2010 and 2013 are simply interesting data points about how cold it can get on Earth, but can’t be used as historical benchmarks or called “records.”
(Jason Samenow contributed to this post)