Dienstag, 7. August 2018

02 data

Temperature change in Jan Mayen and Svalbard 1750-2013
The Arctic region is particularly vulnerable to climate change because the surface air temperatures are increasing at twice the global rate.[14] The special climate of Svalbard - which includes the winter with perpetual darkness (October - February) and summer with perpetual light (April - August) - has a clear effect on the ecology, with many of the endemic species specially adapted to survive the particular harsh environment.[15]
Svalbard also has among the world's fastest moving glaciers. Since the landmass is warming at double the global rate, the shear amount of spring meltwater that runs under the ice lubricates the bedrock enough to make the glaciers surge forward at 25 meters per day during the warm periods.[15]

PermafrostEdit

Permafrost is ground that is permanently frozen, which most of the land in the Arctic is. Monitoring of permafrost in Svalbard is an ongoing process and is mostly done in boreholes. Janssonhaugen, 20 km from Longyearbyen, is a popular monitoring site. There is usually no disturbance to the progress of the temperature thanks to no significant or no circulation of groundwater in the cold permafrost. This makes it easier to observe the changes in the temperature at a depth of 30-40 meters. Through the collected data, the changes in temperature that have taken place near the surface over the past 10-20 years can be calculated. Permafrost monitoring began in 1998 and analyses since then have shown that the temperature is rising. On average the upper part of the permafrost temperature is rising by 0.8°C per decade and has been accelerating during the past decade.[16]
The rise in the air temperature is one of the main reasons for the permafrost thawing at Janssonhaugen. Since all buildings, roads, bridges, airports and other infrastructure are built on permafrost in Svalbard there will be consequences. When warming and thawing of permafrost occurs buildings and infrastructure will be affected and more unstable. Permafrost is essential for stabilising steep mountainsides, which may also become more unstable and cause landslides in the summer. Thawing of permafrost is directly connected with warmer summers. Due to the risk of increasing erosion in the summer, many cultural heritage remains that are situated in the shore zone may be vulnerable and at risk. The most important consequence, on a circumpolar level, is if the deeper layers of the permafrost thaw. Large volumes of greenhouse gases such as CO2 (carbon dioxide) and CH4 (methane) may then be released. These gases have been stored in the frozen ground, but when the ground is thawing they are released into the atmosphere. This may lead to a further rise in temperature and more thawing of the permafrost, creating a positive feedback mechanism.[16]

Snow CoverEdit