Pole of Cold

The Poles of Cold are the places in the southern and northern hemispheres where the lowest air temperatures have been recorded.

Southern hemisphere

Lake Vostok composite image (NASA)

In the southern hemisphere, the Pole of Cold is currently located in Antarctica, at the Russian (formerly Soviet) Antarctic station Vostok at 78°28′S 106°48′E / 78.467°S 106.800°E. On July 21, 1983, this station recorded a temperature of −89.2 °C (−128.6 °F). This is the lowest naturally occurring temperature ever recorded on Earth. Vostok station's location at the elevation of 3,488 metres (11,444 ft) above sea level, far removed from the moderating influence of oceans (more than 1,000 kilometres (620 mi) from the nearest sea coast), and high latitude that results in almost three months of civil polar night every year (early May to end of July), all combine to produce an environment where temperatures rarely rise above −25 °C (−13 °F) during summer and frequently fall below −70 °C (−94 °F) in winter. By comparison, the South Pole, due to its lower elevation, is, on average, 5 to 10 °C (9 to 18 °F) warmer than Vostok, and the lowest temperature ever recorded at the South Pole is −82.8 °C (−117.0 °F).

It is generally thought that Vostok is not the coldest place in Antarctica, and there are locations (notably, Dome A) that are modestly colder on average. Monitoring stations in Antarctica are few and far between; prior to 1995, Vostok was the only research station on the Antarctic Plateau above the elevation of 3,000 metres (9,800 ft), with no other stations for several hundreds of kilometers in any direction. Temperatures below −89.2 °C (−128.6 °F), if they did occur elsewhere, would not have been recorded. The automatic weather station at Dome A was only installed in 2005, and has recorded −82.5 °C (−116.5 °F) as the coldest so far (2010). However a review of satellite measurements taken between 2010 - 2013 found several places located along a ridge between Dome A and Dome F which recorded even lower temperatures of -92 to -94 °C, with the lowest reliable temperature being -93.2 °C recorded in 2010, at 81.8 °S, 59.3 °E, at an elevation of 3900 meters. The extreme low temperatures are found in hollows slightly below the peak of the ice ridge, where cold air gets trapped as it flows downhill, and since the same low temperature ranges were detected at several different sites along the ridge across multiple years, it is thought this may be the lowest temperature achievable under local atmospheric conditions.[1][2]

Northern hemisphere

In the northern hemisphere, there are two places in the Republic of Sakha (Yakutia), Siberia, Russia that vie for the honour of being considered the "Pole of Cold". These are Verkhoyansk (located at 67°33′N 133°23′E / 67.550°N 133.383°E) and Oymyakon (located at 63°15′N 143°9′E / 63.250°N 143.150°E).

In December 1868 and then in February 1869 I. A. Khudyakov made the discovery of the Northern Pole of Cold by measuring a record temperature of −63.2 °C (−81.8 °F) in Verkhoyansk. Later, on January 15, 1885, a temperature of −67.8 °C (−90.0 °F) was registered there by S. F. Kovalik. This became the new world record, and is still the record for the northern hemisphere. This measurement was published in the Annals of the General Physical Observatory in 1892; by mistake it was written as −69.8 °C (−93.6 °F),[3] which was later corrected. One can still find this incorrect value in some literature.

In 1924, Russian scientist Sergey Obrychev registered the lowest temperature −71.2 °C (−96.2 °F). On February 6, 1933, a temperature of −67.7 °C (−89.9 °F) was recorded at Oymyakon's weather station.[4] The weather station is in a valley between Oymyakon and Tomtor. The station is at 750 metres (2,460 ft) and the surrounding mountains at 1,100 metres (3,600 ft), causing cold air to pool in the valley: recent studies show that winter temperatures in the area increase with elevation by as much as +10 degrees C (+18 degrees F).[5]

The conventional practice is to round the measurement to the nearest degree Celsius. In this convention, the two places share the northern hemisphere record of −68 °C (−90 °F). On the other hand, some meteorologists say it is wrong to compare the data measured in different years with different equipment and different uncertainties. A more correct procedure is to compare average temperatures over large periods of time. On the average, the temperature at Oymyakon appeared to be lower than at Verkhoyansk over 70 years of simultaneous observations.

Another possible candidate is Mount Logan in Canada which recorded a temperature of −77.5 °C (−107.5 °F) in May 1991. This is controversial as it is at a very high elevation, nearly 6,000 metres (20,000 ft).[6]

See also

References

External references