Before analysis of satellite data, the coldest temperature measured on Earth had been minus 89 Celsius, recorded on the East Antarctic Plateau at Russia's Vostok Station in July 1983.
However, weather stations are not always reliable because they can't measure temperatures over an expansive area.
So in 2013, Dr. Scambos and colleagues chose to analyze data from several Earth-observing satellites to see if they could find temperatures on the plateau even lower than those recorded at Vostok.
Shaded relief map of the East Antarctic Plateau with red-yellow-blue color scale indicating occurrences of thermal emission surface temperatures below minus 90 degrees Celsius; small circles indicate almost 100 regions where observed temperatures of below minus 98 degrees Celsius have occurred, with circle size scaled to number of occurrences.
30 years later, in 2013, American scientists have discovered that the polar plateau there are areas where the temperature reaches -93,2 degrees.
The coldest place on Earth is much colder than previously thought. This time, they also factored in atmospheric dryness of the atmosphere, as drier air makes snow cover lose heat faster, lead study author Ted Scambos, a senior research scientist at the National Snow and Ice Data Center at the University of Colorado Boulder, said in a statement. Past a certain threshold, the air cools so slowly that temperatures can't drop any lower before the weather conditions change.
Pictured, blowing snow conditions at a camp site near Vostok Station in Antarctic summer.
Data from the MODIS instruments is calibrated using temperature measurements from weather stations on the ground. Water vapor concentrations in the atmosphere are increasing, which in turn means more of the ice-emitted heat gets trapped near the surface-keeping it warmer. The satellites suspect that surface temperature of approximately 100 places within this region from 2004-2016 was reduced to minus 144 degrees Fahrenheit.
The researchers behind the study state that this new reading at -98 degrees Celsius appears to be the limit of Earth's temperature. In 2016, NASA recalibrated the MODIS data with more up-to-date weather station measurements, and the researchers reanalyzed the temperature data. Scientists say that the temperature could in theory descend here below, however, this would require that the sky stayed clear longer, and the air was drier.
But how cold can it get?
Interestingly, these locations are spread out over hundreds of kilometers but all have the same lowest temperature. The obvious explanation is that this is, in fact, the coldest it can get on the plateau. In other words, the scientists found minus 98 Celsius seemed to represent the floor or the theoretical minimum for how cold it can get.
"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. These dips in the ice can trap super cold and dry air, according to the researchers.
In the next year or two, scientists are expected to pile up more data by protruding ground-based devices in colder places.