Wednesday, July 11, 2018

Coldest place on Earth has reached lowest possible temperature on the planet

In July 1983, Russia's Vostok Station recorded 89 degrees Celsius and this remains the lowest recorded temperature in a weather station.
Blowing snow conditions at a camp site near Vostok Station in Antarctic summer
The coldest place on Earth is in Antarctica. That comes as no surprise, but what is the lowest temperature that the region has ever reached? A new study has shed light on this question and the results are quite shocking.

Scientists working near the south pole have measured a surface temperature of -100 degrees centigrade in the winter after analysing data that set the previous low record.

The previous lowest temperature recorded in the Antarctic happened in 2013, where a -93 degrees was recorded on the East Antarctic Plateau that covers the South Pole. 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). These results could change the way climate is studied and understood on the planet.

For temperatures to drop this low, scientists believed that the skies must be clear and a gentle wind would be necessary and these were the conditions five years back when the first announcement was made. Now, scientists believe that not only must the skies be clear and a light wind be present, the actual air must also be really dry. Moisture in the air, or humidity is known to trap heat so it must be absent.

Researchers found that all the conditions were being met in small dips or hollows in the Antarctic Ice Sheet. The ultra-cold air is denser and so heavier than the humid air around it, notes the release, so it tends to drop into the hollows and get trapped there, this makes the surface of the ice and the air directly above it drop temperature even further.

"In this area, we see periods of incredibly dry air, and this allows the heat from the surface of the snow to radiate into space more easily," said Ted Scambos, a senior research scientist at the National Snow and Ice Data Center at the University of Colorado-Boulder.

This is the lowest possible temperature on Earth and to achieve this, the skies have to be clear and a slight wind needs to be present for days on end near the South Pole. It might be possible for the temperatures to drop even further, say the scientists, but then these optimal conditions need to persist for weeks, which is unlikely to ever happen in the south pole. For now, this record stands.

In July 1983, Russia's Vostok Station recorded 89 degrees Celsius and this remains the  lowest recorded temperature in a weather station.

The new study was first published in Geophysical Research Letters, a journal of the American Geophysical Union.

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