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2 March 2017

Signy Island - The Hottest Place in the Antarctic

A committee of experts from the World Meteorological Organization (WMO) announced on the 1st of March their list of new records for the highest temperatures ever recorded in the Antarctic Region, with the Signy Research Station topping the table. The results have been collected “as part of continuing efforts to expand a database of extreme weather and climate conditions throughout the world”, according to the British Antarctic Survey (BAS).

Signy Island Research Station   - Img: British Antarctic Survey (BAS)
In this context, the Antarctic Region is defined as “all land and ice shelves south of 60°S”, rather than being restricted to the continent of Antarctica itself.

Following an examination of Antarctic temperature data collected since the beginning of official records in the late 1950s, the Signy Research Station’s record of 19.8°C from 30th January 1982 held onto the title of highest temperature for the Antarctic Region. Situated in Borge Bay on the South Orkney Islands and operated by the British Antarctic Survey, Britain’s sole summer-only research station has been gathering data on bird populations and terrestrial ecology from the region since its first meteorological station was established in 1947.

Member of the WMO Expert Committee and BAS meteorologist, Dr John King, explains the cause of the unprecedented and seemingly isolated rise in temperature the station experienced that year:

“Summer temperatures at Signy can sometimes reach double figures, but this event in January 1982 is pretty unusual. Weather systems in the South Atlantic were bringing exceptionally warm subtropical air southwards towards Signy that year. As this air moved south across the cold Southern Ocean it cooled at low levels but remained very warm above 1 km altitude. This warm air was brought back towards the surface as the air flowed over the mountainous Coronation Island just to the north of Signy – a phenomenon known as a föhn wind. Although average temperatures at Signy have been rising at around 0.2°C per decade, the highest temperature we’ve measured since January 1982 has been 13.8°C, showing just how exceptional that event was.”

Img: World Meteorological Organization (WMO)
While Signy Island does hold the record for highest temperature ever recorded within the Antarctic Region, the Argentine Research Base Esperanza, located near the northern tip of the Antarctic Peninsula, takes the top spot for the Antarctic Continent- defined by the WMO as “the main continental landmass and adjoining islands” – with a high of 17.5°C recorded on 24th March 2015.

The highest temperature ever recorded on the Antarctic Plateau – defined as Antarctic regions “at or above 2500 meters (8202 feet)” – falls significantly lower at just -7°C. The observation was made at Automatic Weather Station (AWS) site D-80 on 28th December 1989.

The WMO does however state that while it is likely that the Antarctic Region has experienced greater extremes in the past, the extremes are identified based on only those events with available high-quality ground-based data, as with all WMO evaluations.

The WMO state that, “The verification of these three Antarctic extremes helps increase understanding about the Antarctic’s distinct climatic regimes, specifically maritime versus plateau environments.” With global warming continuing to pose a threat, attaining a proper understanding of climate in and around the Antarctic Region is of paramount importance.

“This investigation highlights the need to continually monitor all of the Antarctic Region and ensure that we have the best possible data for climate change analysis at both the regional and global scales,” said Randall Cerveny, WMO Rapporteur on Climate and Weather Extremes.

Dr King, it seems, shares this opinion:

“Global temperatures are rising and we are witnessing big changes in the Polar Regions such as the recent rapid reduction of Arctic summer sea ice. Determining temperature extremes for a region is important as it sets a baseline against which climate variability and change can be measured. BAS currently monitors temperature and a range of other climate variables at its five permanent research stations and at a number of remote automatic weather stations scattered across the sub Antarctic islands and the Antarctic Peninsula. These data are shared with the international climate research community and underpin studies of Antarctic climate variability and change.”

At the other end of the scale, the official record for the lowest temperature ever recorded in the Antarctic Region, or anywhere in the world for that matter, still stands at -89.2°C, observed at Vostok Research Station on 21st July 1983. There is, however, some debate about this, as NASA satellite data suggests that this record was broken at the Dome Fuji Ridge in 2010, with a low of -93.2°C.

Sam Bonson

Sam is an aspiring novelist with a passion for fantasy and crime thrillers. He is currently working as a content writer, journalist & editor in an attempt to expand his horizons.