New record for Antarctic continent reported

The Argentine research base, Esperanza, onthe northern tip of the Antarctic peninsula, set a new record temperature of18.3°C on 6 February,beating the former record of 17.5°C on 24 March2015, according to Argentina’s nationalmeteorological service (SMN).

A committee for WMO’s Weather and Climate Extremes Archive will now verify whether  this indeed is a new record for the Antarcticcontinent, which is defined as the main continental landmass.

“Everything we have seenthus far indicates a likely legitimate record but we will of course begin aformal evaluation of the record once we have full data from SMN and on themeteorological conditions surrounding the event. The record appears to belikely associated (in the short term) with what we call a regional"foehn" event over the area:  arapid warming of air coming down a slope/mountain,”according to WMO’s Weather andClimate Extremes rapporteur, Randall Cerveny.

Verification of this maximum temperaturerecord is important because it helps us to build up a picture of the weatherand climate in one of Earth’s finalfrontiers.” The Antarctic, likethe Arctic, is poorly covered in terms of weather observations and forecasts,even though both play an important role in driving climate and ocean patternsand in sea level rise.

The record for the Antarctic region – that is, everywhere south of 60 degrees latitude – is 19.8C, taken on Signy Island in January 1982.

The Antarctic Peninsula (the northwest tipnear to South America) is among the fastest warming regions of the planet,almost 3°C over the last 50years.  The amount of ice lost annuallyfrom the Antarctic ice sheet increased at least six-fold between 1979 and 2017.Most of the ice loss takes place by melting of the ice shelves from below, dueto incursions of relatively warm ocean water, especially in west Antarctica andto a lesser extent along the peninsula and in east Antarctica.

Spanning 14 million km2 (roughly twice thesize of Australia), the Antarctic is cold, windy and dry. The average annualtemperature ranges from about −10°C on the Antarctic coast to −60°C at the highest partsof the interior. Its immense ice sheet is up to 4.8km thick and contains 90% ofthe world’s fresh water, enoughto raise sea level by around 60 metres were it all to melt.

Pine Island Glacier

Some 87% of glaciers along the west coastof the Antarctic Peninsula have retreated in the last 50 years with most ofthese showing an accelerated retreat in the last 12 years.

Pine Island glacier.Cracks in the PineIsland Glacier in Antarctica have been growing rapidly over the last days,according to satellite images from Europe’s Sentinel1. The Pine Island Glacier is one of the primary icearteries in the West Antarctic Ice Sheet. The two large rifts were firstspotted in early 2019 and have each rapidly grown to approximately 20 km inlength.

Pine Island glacier, like its neighbouringThwaites Glacier, has been dramatically losing ice over the last 25 years.Owing to their extremely remote location, satellites play a critical role inmeasuring and monitoring Antarctic glaciology – revealing the timing and pace of glacial retreat in Antarctica.

Recently, the frequency of Pine IslandGlacier calving events has increased. Today, the glacier is observed to belosing mass by a combination of calving events together with strong basalmelting, where warm ocean currents erode the underside of the floating iceshelf. As the ice shelf both thins and calves enormous icebergs, the glacierdischarge is unable to replenish the ice lost and the ice shelf front recedesfrom its previous position.

Thwaites Glacier

Antarctica’s Thwaites Glacier has been in the spotlight in recent years, asscientists have undertaken a multi-part international project to study the vastglacier from all angles. The urgency stems from observations and analysesshowing that the amount of ice flowing from Thwaites—and contributing to sea level rise—has doubled in the span of three decades. Scientists think theglacier could undergo even more dramatic changes in the near future, accordingto NASA’s EarthObservatory.  Indeed, Thwaites Glacier isone of the largest contributors to global sea level rise from the WestAntarctic Ice Sheet.

(Source: WMO News)