New Planetary Cold record discovered? Not so Fast!
As Jeff Masters blogged on December 10th
satellite data indicates that a temperature of -93.2°C (-135.8°F) had been measured at a site near Dome Argus in Antarctica on August 10, 2010, colder than any land-based measurement from the frozen continent (that being Vostok’s -89.2°C/-128.6°F on July 21, 1983). Unfortunately, many media outlets headlined this as a “new coldest temperature recorded on earth”. This is not the case, however, so far as being an ‘official’ earth record.
Satellite earth skin temperature measurements will never be accepted as ‘official’ weather observations no matter how accurate their data might be. As Vyacheslav Martyanov, the head of the Russian Antarctic Expedition's logistics center, put it in an interview for RIA Novosti (A Russian News Organization): “It is incorrect to declare a temperature record based on satellite data. AVHRR and MODIS are measuring the so-called ‘luminance temperature’, which does not fully correlate with true meteorological conditions and must be confirmed by observations on the ground.
Air temperature is measured according to standards, at the height of 2 meters above the ground, like they do at meteorological observing stations, therefore recognizing a temperature measured by remote sensing is unrealistic”
This holds true as well for the often cited 70.7°C (159.3°F) “hottest temperature on earth” measured by MODIS in July 2005 at a remote location in the Lut Desert of Iran.
That being said, the MODIS Antarctica figure is probably closer to the truth than the Lut Desert figure since heat radiating off the desert ground in Iran would have naturally related to much hotter figures than what would have been observed had a standard weather shelter been in place at the same location. This would not have been an issue in Antarctica during its winter months. Furthermore, the location is at or near the highest point on Antarctica’s continental dome at some 4000 m (about 13,000’). The nearest weather station to the point where the cold temperature was measured is Dome Argus (also known as Dome A). See map below:Map of Antarctica illustrating where the satellite measurements were taken in relation to Dome Argus and Vostok.
Ted Scambos, National Snow and Ice Data Center.
Unfortunately, I cannot find the temperature data for Dome Argus for either August 10, 2010 or July 31, 2013 to compare to the satellite data. However, Vostok 600 meters (almost 2000’) lower than Dome Argus and, admittedly far away) did measure -110°F (-78.9°C) on July 30, 2013 and -103°F (-75.0°C) on July 31, 2013. The coldest RAWS site for the day of July 31 was -81.7°C (-115.1°F) at Davis Lab 46 located at 75.51 S, 71.29 E and at just 2354 m (7,700') elevation. One can imagine, therefore, that it most likely was considerably colder at Dome Argus or at the satellite data point on those dates (although not unquestionably given the distance from Vostok and Davis Lab 46). Also, this past summer (2013) was one of the warmest on record for much of Antarctica, especially the dome region. Vostok failed to drop below -80°C for its first time ever (POR (back to 1957) and the same goes for Dome Fuji. This begs the question of just why this little satellite data point seems to have bucked this trend (of an unusually warm winter on the dome) and yet coming up with a temperature so far away from the land site observations!A photograph of the weather station at Dome Argus (Dome A) taken shortly after its installation in 2005.
Photo credited as CHINARE and from the Australian Bureau of Meteorology web site.
Since Dome Argus was established in 2005 the coldest temperature measured there has been ‘just’ -82.5°C (-116.5°F) in July 2005 (although that was for the POR of only 2005-2010). One may assume that one of these days it is almost certain that Dome Argus or one of the other high altitude RAWS stations are going to actually measure a temperature colder than Vostok’s.
Christopher C. Burt