Monitoring Surface Climate around Longyearbyen, Svalbard

 

Photo: Hanne H. Christiansen

Ole Humlum, UNIS, Department of Geology, Svalbard, Norway

A project on the Physical Geographical Environment funded by the University Courses on Svalbard (UNIS) 2000-2005

 

Background

The physical landscape is widely understood as a collective term for the association of individual terrain elements on Earth, such as e.g. valleys, rivers and dunes. Generally speaking, the landscape has long been considered as being quite stable, and major ‘changes’ was a concept reserved for the geological remote past and in particular for the great ice ages. Given a constant situation, it was supposed that the environment does not either change or fluctuate. If the landscape could be said to ‘change’ it was presumed that the changes were in the nature of a deterministic response of the landscape-atmosphere coupling to extrinsic changes, for example volcanic dust injections into the upper atmosphere, or changes of solar irradiance alleged to be associated with sunspot cycles.

The modern concept of the landscape differs in that it downplays the statistical notion of its components as stable units. Instead it stresses the entirely different notion of the landscape as a dynamic physical system, very much controlled by and interacting with climate. Several types of important energy exchange takes place at the interface between the atmosphere and the physical landscape.

 

Monitoring meteorological parameters

In order to gain insight in the local meteorological control on various landforms a number of meteorological stations have been established in the terrain around Longyearbyen. One station is a standard meteorological station and is located to the eastern part of Janssonhaugen in upper Adventdalen, about 25 km from Longyearbyen.

 

Meteorological station at Janssonhaugen, upper Adventdalen, central Spitsbergen, 9. May 2000. In the background is seen the top of the PACE borehole, where permafrost temperatures are measured from the surface to a depth of 102 m.

 

This station (275 m asl.) was established 9. May 2000 in order to obtain detailed information on the meteorological conditions at the PACE (Permafrost and Climate in Europe) borehole, where permafrost temperatures in bedrock have been measured since May 1998 to a depth of 102 m.

At several other locations a number of rugged, waterproof and small-scale dataloggers (Gemini Dataloggers) have been installed to register surface air temperature, relative air humidity and precipitation on a number of selected landforms. This research scheme will yield data on meteorological conditions at various altitudes, exposures, slopes, distance to the sea, etc. The type of dataloggers are relatively inexpensive and have battery power and sufficient internal memory (EPROM) enabling them to operate with hourly measurements up to more than two years without being serviced. They have previously been thorough tested in Greenland, Iceland, the Faroe Islands and in the highlands of Scotland.

 

Types of dataloggers used for measurement of temperature (with thermistor), precipitation and humidity.

 

In contrast to standard meteorological stations, where measurements usually are done 2 m above the ground, these dataloggers measure the meteorological condition directly at the terrain surface. Meteorological observations from the ground surface itself is, however, is of prime geomorphic importance for understanding both past and present activity of various terrain elements in the landscape. Unfortunately, this kind of ground surface meteorological observations have only been carried out in few other cases, although the data are highly important for geomorphic research and for understanding energy exchange between the atmosphere and the landscape. The data resulting from this study also serve as control for modeled terrain surface temperature, precipitation, etc. Visual data from another research initiative on automatic registration of the distribution and duration of the seasonal snow cover yield an important background for understanding and analyzing the meteorological conditions registered by the present research scheme. 

 

Precipitation gauge and datalogger (invisible in photo) installed on the slope above the restaurant 'Huset'.

 

Examples of registered temperatures

Click here to go to interactive photo of Longyearbyen and surroundings with examples of measured temperatures and other parameters.

 

Monitoring active layer temperatures and depths

The mean annual air temperature at sea level is about -6oC near Longyearbyen. Permafrost is therefore widespread, even at sea level. The active layer is the zone above the permafrost that experiences seasonal freezing and thawing, and is considered to be the locus of several important sets of dynamic processes, including biological, pedologic, geomorphic, biogeochemical, and hydrologic. Despite its importance to a wide variety of physical and biological investigations, information about development of the active layer has rarely been collected in a systematic, standardized fashion over large areas.

Should the annual thaw depth increases due to some future climatic variation in air temperature, precipitation or wind, some of the carbon and water currently sequestered in the permafrost reservoir could be released. A net increase in the efflux of CO2 and H2O to the atmosphere would presumably provide a positive feedback effect on global or regional warming. Interannual, decadal and secular variations in the active layer thickness is therefore now monitored on a hemispheric scale, so as to better understand the roles of cold soils in global climatic change. Forecasting and observing changes in the active layer and upper permafrost have direct applications to technogenic landscape processes, related infrastructure, and human activities.

To achieve these goals, the CALM (Circumpolar Active Layer Monitoring) program has been established. It currently consists of 69 research sites operated by researchers from Austria, Canada, China, Denmark/Greenland, Kazakstan, Poland/Svalbard, Russia, Sweden/Svalbard, Switzerland, and United States. Although the CALM program began as a voluntary effort in 1991, it has recently been formalized with a 5-year grant from the U.S. National Science Foundation (NSF). Investigators at these sites measure the seasonal thaw depth across plots using a standard protocol. Soil and air temperature, and soil moisture content, are also measured at many sites. If these areally averaged measurements are combined with site-specific information on soil, landscape, vegetation, and measurements of air and soil temperature, the stability and projected changes in regional thaw depth and the spatial patterns can be more realistically modeled and validated.

 

CALM-site in Adventdalen being established 18. July 2000.

 

At Longyearbyen a 100x100 m CALM-site has been established in July 2000, near the old airport in lower Adventdalen (photo above). The site is subdivided into a 10 m grid, where the active layer thickness is monitored during the summer season with a thin metal rod calibrated in centimeter increments. The rod is pushed vertically into the soil to the depth at which ice-bonded soil provides firm resistance. This kind of measurement provides provides information about the rate and maximum depth of thaw in the site. Active layer temperatures are monitored hourly on a year-round basis by 7 permanently installed dataloggers of the type described above. Data from the site is now theme for a master thesis.

A second UNIS-driven CALM site was established August 2001 near Ny-Ålesund, about 140 km NW of Longyearbyen. 

Click here for more information on these two CALM-sites.

 

Relevant LINKS

Below you will find some useful links to web sites with information about permafrost, active layer, etc:

The International Permafrost Association

Circumpolar Active Layer Monitoring (CALM)

Global Terrestrial Network-Permafrost (GTN-P) - borehole monitoring

Arctic Coastal Dynamics (ACD)

Permafrost and Climate in Europe (PACE)

 

 

 

Latest update: 3. January 2006.