Year 2000-today

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2001-2003: Jakobshavn Isbræ in West Greenland retreats rapidly       

Frontal positions of calving Jakobshavn Isbræ since 1851, after reaching the maximum Little Ice Age position around 1850 (Bauer et al. 1968). Between 1893 and 2003 the glacier front retreated about 34 km. According to inuit legends, the embayment Tissarissoq used to be glacier-free in the past and was used as hunting area (Hammer 1883), most likely before before the Little Ice Age glacier advance (Weidick et al. 2004). Picture source: Google Earth.

 

The Disko Bay region in central West Greenland (c. 70oN) is characterised by large outlet glaciers from the Greenland Ice Sheet (the Indland Ice). The major glacier Jakobshavn Isbræ is situated in a major subglacial valley, which can be traced inland for about 100 km (Echelmeyer et al. 1991). The water depth in the fjord reaches 1500 m in its outer parts (Iken et al. 1993). 

Jakobshavn Isbræ is the main outlet glacier from the Greenland Ice Sheet, draining ice from about 6.5% of the total area of the ice sheet, and producing 30-45 km3 icebergs per year. This corresponds to more than 10% of the total output of icebergs from the Greenland Ice Sheet, and the Jakobshavn Isbræ is the most productive glacier in the northern hemisphere. The glacier flow velocity is also high, typically 20-22 meters per day. It is likely that the iceberg which sank Titanic in 1912 may have been produced by Jakobshavn Isbræ.

The first half of the 20th century was characterised by a 11 km frontal retreat of calving Jakobshavn Isbræ, following warming after the end of the Little Ice Age. During the latter half of the 20th century the glacier front was in an almost stable position, standing across a broad section of the fjord. Presumably, the quasi-stable glacier front position was influenced by the subglacial topography (Echelmeyer et al. 1991; Weidick 1992).

During the period 1850-1950 it has been estimated the the Jakobshavn Isbræ lost more than 200 m in ice thickness (Weidick 1992), gradually making is more easy for the glacier to float. Also between 1960 and 1980 the glacier thinning proceeded (Echelmeyer et al. 1991). Between 1993 and 1998 a slight thickening may have taken place (Abdalati et al. 2001), but from 1998 rapid thinning again dominated, spreading inland. The reduced ice thickness gradually made the glacier more prone to floating and thereby rapid calving, and around the year 2000 substantial changes of the calving front were therefore expected to take place (Weidick et al. 2004).

The expected rapid calving retreat took place from 2001 to 2003. In 2002 people living in Ilulissat observed unusually many icebergs in the icefjord, and observations carried out in 2003 further inland showed the floating glacier front to have retreated many kilometres (see picture above). At the same time, however, the position of the land-based glacier front of the ice sheet north and south of the floating glacier front has been stable. Thus, the spectacular calving retreat 2001-2003 should not be seen as a direct result of meteorological conditions during this short period, but instead reflects developments over a longer period. In addition, the depth and geometry of the fjord also influences on the retreat rate. Finally, the early 21st century air temperature in West Greenland is still clearly below what was recorded around 1940. Click here to see the entire temperature record from the capital at Nuuk, south of Jakobshavn.

Descriptions of the previous retreat of the glacier Jakobshavn Isbræ during the periods 1851-1893 and 1893-1942 can be found here and here, respectively.

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2006: Winter storm Narve in Northern Norway and record high temperature in Svalbard    

Examples of weather related news from different part of Russia and Europe during the period 16-23 January 2006.

 

The severe January 2006 winter storm named 'Narve' created chaos in especially northern Norway, but also larger of Norway, Sweden and Finland were affected. In the press it was presented as an example of 'extreme weather'.

The wind over a period of several days from 15 January increased from southerly and southeasterly direction, developing into a strong storm, almost reaching hurricane-like conditions during 19 January. The storm was not associated with much precipitation in northern Norway, but with air temperatures down to -25oC, exposing people to serious wind chill and frostbites. Many buildings were damaged by the wind and by flying debris.

At the same time a new high temperature record of was reported for Svalbard (78oN), about 1000 km north of Norway.

Many powerlines in northern Norway came down, and large areas, including the cities of Tromsø and Kirkenes lost electricity and heating. In southern Norway the southeasterly wind resulted in an ongoing blizzard for orographic reasons, as the air masses were lifted across the highlands after flowing across the ice-free sea south of Norway, picking up additional moisture. Also in this part of Norway powerlines failed, not so much because of the wind, but because of excessive amounts of snow. The storm lead to major disturbances for both railways and air traffic. Several major highways were closed because of large snowdrifts, and schools had to be evacuated both in southern and northern Norway.

Narve lasted to 21 January, before slowly beginning to abate. Because of the duration and strength, the storm immediately earned itself a place on the official list of 'extreme weather in Norway', indicating the special status of this meteorological event.

 

Weather maps showing surface air pressure and surface air temperatures over Europe 12, 16, 18 and 21 January 2006. Solid lines indicate lines of equal air pressure (isobars) and the colours indicate the temperature in degrees C. Sub-zero air temperatures are shown with green and blue colours, while above-zero temperatures are shown by yellow and red colours. Over the period the high pressure area with low air temperatures are seen to extent across eastern Europe, concentrating thermal and pressure contrasts over northern Norway and Sweden. Source: Universität zu Köln, Institut für Geophysik und Meteorologie.

 

The meteorological background for this storm was a large east-west air pressure gradient across northern Norway, because of a low pressure area over the North Atlantic and a high pressure over Russia and Finland. Actually, the high pressure area was a westerly extension of the Siberian high pressure area, which increased in extension to cover parts of eastern Europe as well because of extreme cold in Siberia and Russia. 

The record high air temperatures recorded in Svalbard was caused by the southerly air flow across the warm waters of the North Atlantic Drift, warming up the air masses before reaching Svalbard. The strong southerly winds also pressed the southern limit of Arctic sea ice around Svalbard further north than usual.

By this, both the new air temperature record in Svalbard and the northerly position of the sea ice limit was a result of the extended position of the Siberian high pressure. Unfortunately, this greater meteorological perspective was never clearly communicated by the relevant meteorological institutions. Therefore, many people even today see both features as the result of global warming. In reality, they were both results of cold conditions in Russia and Siberia.

 

Maps showing the anomaly of surface air temperatures January 2006, compared to average conditions 1998-2006. Much of the northern hemisphere was colder than average, especially Alaska, Siberia, Russia and Europe. In contrast, USA and Canada experienced warmer than average conditions, as did an area extending from northeast Greenland across Svalbard to the Taymyr peninsula in northernmost Siberia. This warm regional anomaly is the result of persistent airflow from SW across the North Atlantic, along the western extension of the Siberian high pressure (see diagrams above). By this, this part of the Arctic experienced above average temperatures in January 2006, leading to the above mentioned temperature record in Svalbard. Temperature scale in degrees Celsius. Data source: NASA Goddard Institute for Space Studies (GISS).

 

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2008: Coastal erosion prompts Inuits in Alaska to sue oil and gas companies    

The location of the settlement Kivalina (ca. 68N, 165W) in northwestern Alaska. Kivalina is located on the northeastern shore of the Bering Strait. Easternmost Siberia is seen to the left. The picture measures about 2500 km from left to right. Source: Google Earth.

 

Inuits living in the coastal settlement Kivalina in northwestern Alaska (see location map above) are suing 24 oil and gas companies (February 27, 2008), claiming that sea ice melt caused by global warming poses an imminent threat to the Inupiat Eskimos who live there. Kivalina is located at the coast 70 miles north of the Arctic Circle, and have about 390 inhabitants. The complaint says that because of massive sea ice melting, the village is losing its traditional protection from weather and the village must relocate.

 

Arial photo of Kivalina, showing the partly ice covered Beiring Strait to the left, and land with rivers and lakes to the right. Kivalina is seen to be located on the coastal barrier island, separated from the mainland by a lagoon. The picture measures about 10 km from left to right. North is up. Source: Google Earth.

 

From a geomorphological point of view, the setting of Kivalina is interesting. The press release say that Kivalina is located on the tip of a barrier reef. This is not the case. The picture above shows the settlement to be located on a coastal barrier island (or shoal), caused by wave action, and thus demonstrating the occurrence of one or several previous periods with extensive open water conditions in the area, extensive enough to generate big waves. If not so, there would have been no barrier island to establish the settlement on. Thus, the present conditions with relatively little sea ice has most likely occurred one or several times before. Actually, in August 1728 Vitua Bering came close to Kivalina, sailing in open water. 

The barrier island on which Kivalina is located must be a relatively new landscape feature, geologically speaking. It is adjusted to the present relative sea level (relative to the land), which in this area probably was reached about 3000-4000 years ago. During this time interval the barrier island have been established by storms during previous open water situations.

Coastal barriers are notorious dynamic landforms, changing form, location and surface relief along with changes in wave activity, wind direction and -strength, and the supply of new sediments (usually sand) by rivers from the hinterland. In periods with high precipitation and high summer river discharge and resulting high sediment transport by rivers, coastal barrier islands tend to aggrade, while the opposite (erosion) dominates in periods with little supply of sediment by nearby rivers. Therefore, not only variations in sea ice, but also a number of other climatic and geomorphological factors control the fate of such delicate coastal features. Usually, coastal barrier islands are considered problematic locations for buildings, roads and other fixed installations. Especially locations near outlets from rivers or lagoons behind are exposed to rapid changes in the coastal outline.

In the Arctic mosquitoes represent a major nuisance, especially in July. Presumably the location for Kivalina was chosen to avoid mosquitoes from the many lakes in the hinterland, and to be close to the open sea during the open water period (summer). The number and outline of the numerous lakes in the hinterland signal the existence of permafrost in the area. Barrier islands tend to orient themselves perpendicular to the dominant wind direction during the open water period (summer). In the present case the prevailing summer wind direction apparently is from southwest, helping to keep the mosquitoes at bay in the hinterland, away from Kivalina.

 

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