According to an global team of researchers who used 12 years' worth of data from several Earth-observing satellites and weather stations to reassess the same region, the temperatures prevailing in tiny valleys of Antarctic ice sheets can drop close to a whopping minus 98 degrees Celsius (or minus 148 degrees Fahrenheit), which is five degrees lower than originally thought. A negative 100 degrees Celsius is also likely to be the lowest possible temperature that Earth can naturally reach, says a release by the American Geophysical Union (AGU).
Previously, the record low temperature was recorded in July 1983, Soviet scientists from the station "Vostok".
Since it is impossible to install a weather station in the area, Scambos and his team looked at satellite data from 2003 to 2016 to see just how cold it got in the area.
So low temperature, as shown by the satellite data were recorded in a few small depressions (depth up to 3 meters) in the Eastern part of Antarctica during cloudless and dry weather.
Remarkably, the lowest temperatures observed at all of these hollows on the ice sheet was right around minus 98 Celsius, even though some of them were spaced tens of miles apart. Temperatures on certain spots in the frozen ridge were found to have plunge further to negative 148 degrees Fahrenheit, or negative 100 degrees Celsius, which is a new mark for the coldest temperature in the world ever recorded.
Clear skies, light winds and dry air can drop temperatures as low as minus 144 degrees Fahrenheit.
"In this area, we see periods of incredibly dry air, and this allows the heat from the snow's surface to radiate into space more easily", said lead author Ted Scambos of the National Snow and Ice Data Center at the University of Colorado-Boulder in a statement.
However, the conditions have to be ideal for the temperatures to hit that landmark low.
Blowing snow conditions at a camp site near Vostok Station in Antarctic summer.
The scientists also developed a set of instruments created to survive and operate at the very coldest places through the winter and measure both snow and air temperatures. But the new study adds a twist to the story: Not only are clear skies necessary, but the air must also be extremely dry, because water vapor traps some heat in the air. As a result, the surface and air get even colder, keeping this hollow ultra-cold until conditions change.
In 1926, there was recorded temperature -71,2 degrees Celsius (according to unofficial data, in 1938 - -77,8 degrees Celsius).
'There's a limit to how long the conditions persist to allow it to cool to these ultra-low temperatures, and a limit to how much heat you can actually get through the atmosphere, because water vapor has to be nearly nonexistent in order to emit heat from the surface at these temperatures, ' he said.
In 2013 and in the new study, researchers calibrated the same satellite measurements of surface temperatures with data collected from weather stations on Antarctica's surface.
Interestingly, these locations are spread out over hundreds of kilometers but all have the same lowest temperature.
How cold can it get? That got them wondering: Is there a limit to how cold it can get on the plateau?
Note that this isn't the same as the lowest temperature ever recorded using instruments at ground level. They are planning to deploy the instruments within the next two years.