Sweden: projects/activities

An alternative for metal deposition measurements is to analyze their abundance in mosses since metals bind strongly to cation exchange sites in them. The concentration of metals in mosses would therefore act as an index for metal deposition. It is also assumed that uptake of most water and dissolved substances comes directly from precipitation; even if it has been shown that capillary transport of dissolved metals may be substantial. A national inventory of metals in mosses takes place at 5-year intervals (Table 4, #1.11). The two-to-three last years growth is identified and collected for chemical analysis ICP-AES and ICP-MS (As, Cd, Hg) Metals are adsorbed by mosses and metal concentration in mosses are therefore seen as a proxy for metal deposition. Moss species: Pleurozium schreberi, Hylocomium splendens Analyzed metals: As, Cd, Cr, Cu, Fe, Hg, Ni, Pb, V, Zn Sampling sites: More than 700 sites over Sweden Time period: 1/5 years, first report 1975 and last reported 2005.

The tree limit has been monitored since 1915 at some sites in the Swedish mountains. The Department of Ecology, Environment, and Geosciences (EMG) at Umeå University, and Jämtland and Dalarna county boards monitored about 300 sites along the Scandinavian mountain chain for upper elevation trees taller than 2 m (Öberg, 2007).

Since 1962, the soil inventory (RIS-MI) and the national forest inventory (RIS-RT) have had a common field organization. The soil inventory investigates soils and collects soil samples for laboratory analysis. It includes several soil variables, e.g. soil type and soil classification, stone and boulder abundance, water relations, and soil chemistry. Simultaneously to the soil inventory, RIS–MI samples the field layer vegetation.

At present SEPA’s program on wetlands is mainly a follow-up on wetland states, e.g. hydrological intactness and biodiversity. On the other hand, wetlands are part of the national inventory of landscape, NILS (see above). Wetland status is embraced by reporting obligations according to the EU Habitat Directive, and SEPA now uses high-resolution satellite data for operational monitoring.

The National Inventory of Landscapes in Sweden (NILS) is a sample-based, nationwide environmental monitoring program focused on biodiversity. NILS started in full scale in 2003 and is based at the Department of Forest Resources Management, SLU. The program includes all terrestrial environments in Sweden, including agricultural land, wetlands, urban environments, forests, and mountains. NILS is based on 631 permanent sampling squares of 1 km x 1 km (Fig. 4). Within each square, 12 sample plots are field surveyed and an air photo interpretation is done for the whole area. A more extensive air photo interpretation within wider squares of 5 km x 5 km is also planned. The program will have a rotation time of 5 years. Results from NILS are intended to follow up on the national environmental objectives, land use status and change, and the distribution and area of different biotopes (Table 4, #5.1). The NILS program is divided into several subinventories, i.e. the general landscape (Table 4, #5.1), the mountains (Table 4, #2.1), arable land (Table 4, #4.6), and wetlands (Table 4, #6.3).

Swedish forestry practice includes a final clear felling after a rotation of up to about 100 years. To follow up on cutting permits, the Swedish Forest Agency (SST) annually maps all new clear felled areas, using satellite image data from the present and the previous year. This practice, carried out by a government agency, also creates a yearly nationwide database with SPOT or similar satellite image data, which has created the base for the above mentioned SACCESS national satellite data archive

SLU combines the spectral information from SPOT, or similar satellite image data, with the field data information from the national forest inventory plots. The result is a nationwide raster database (pixel size 25x25 m) where each grid cell is coded with the stem volume for the major tree species categories (pine, spruce, deciduous), and tree height. The product, which is called kNN-Sweden after the algorithm used, is repeated every fifth year, starting with images from year 2000. The kNN database can be downloaded free of charge from http://skogskarta.slu.se/

Increasing temperature in the Arctic will increase the soil temperature and decrease the area covered by permafrost. Depending on the situation, microbial decomposition of stored soil organic carbon will increase and release carbon dioxide and eventually methane, two greenhouse gases that may accelerate climate change. Some international programs study permafrost development. At 1540 meters altitude in Tarfala, temperature is measured in one borehole down to 100 m and another down to 15 m below soil surface in the Permafrost and Climate in Europe (PACE) program coupled to the Global Terrestrial Network for Permafrost (GTNP) (Table 5, #2.5). Four more shallow, boreholes near Abisko are suggested candidates for PACE, one managed by Luleå Technical University and three managed by Lund University (Table 5, #1.21). Abisko Research Station carries out manual sonding of the active permafrost layer at Stordalen, an activity on behalf of Geobiosphere Science Center (CGB), Lund University and part of the Circumpolar Active Layer Monitoring (CALM) (Table 3). The active layer has been monitored at 11 sites along an 80 km east-west profile from 1978 to 2002. Eight of these were bog sites situated in a transect from the dry and cold east to the milder and wetter west, all at approximately 390 m altitude. Permafrost monitoring started in 1972 at Kapp Linné, Svalbard, by the Geobiosphere Science Center (CGB), Lund University (Table 5, #23), and was reported for the period 1972 to 2002. Soil moisture and soil temperature were also monitored. The 10 monitoring sites differed in vegetation cover, elevation, substrate, active periglacial processes, and distance to the sea.

The earliest record of lake ice break-up in Sweden is from as early as 1701, when the ice on Torne River at Haparanda melted on May 31st. Since then SMHI has successively extended the ice observation network. By 1900 the network included about 150 sites, and by 1950 it included over 320 sites (Table 6, #2). By 1950, observations had been terminated at only 9 sites. During the following 50 years 72 new sites were added to the network while observations were terminated at 255 sites. The reason for the extensive network during the latter nineteenth century and the early twentieth century was the use of frozen lakes and rivers for transportation, but also the need to know when spring activities, e.g. floating timber, could commence. The ice broke up on Torne River at Haparanda, on average, on May 20th during the eighteenth century, on May 17th during the nineteenth century, and on May 10th during the twentieth century, indicating a long-term trend of earlier lake ice break up.

Mass balance measurements started at Storglaciären in the Kebnekaise massif in 1946 (Table 5, #2.1). At present, the measurements comprise a mass balance of 5 glaciers in the area. In calculating one year’s mass balance, measurements are taken twice per year (in winter and summer) and mass balances are calculated annually by the Department of Physical Geography and Quaternary Geology at Stockholm University (SU-INK). Measurement of glacier fronts is a simpler alternative to mass balance calculations that could be used as an index for mass balance. Stockholm University (SU-INK) performs such front measurements at 18 glaciers every second year (Table 5, #2.2).

The total column amount of ozone and other trace gases are measured with mm-wave instruments, FT-IR and DOAS spectrometers, at IRF in Kiruna (Table 6, #8.1). With the sun or moon as infrared light sources, FT-IR spectrometers can quantify the total column amounts of many important trace gases in the troposphere and stratosphere. At present the following species are retrieved from the Kiruna data: O3 (ozone), ClONO2, HNO3, HCl, CFC-11, CFC-12, CFC- 22, NO2, N2O, NO, HF, C2H2, C2H4, C2H6, CH4, CO, COF2, H2O, HCN, HO2NO2, NH3, N2, and OCS. Together with Russian and Finnish institutes at the same latitude, IRF studies the stratospheric ozone and its dependence on polar atmospheric circulation and precipitation of charged particles. The ground-based instruments are also used to validate satellite measurements of vertical ozone distribution (Odin, SAGE III, and GOME). Aerosols and thin clouds are measured at IRF in Kiruna. For example, researchers use Lidars (Light Detection and Ranging) to measure polar stratospheric and noctilucent clouds. Winds and structures are measured with ESRAD MST radar at IRF in Kiruna. At IRF in Kiruna measurements are used to assess the physical and chemical state of the stratosphere and upper troposphere and the impact of changes on the global climate. Particle precipitation is measured by relative ionospheric opacity meters (riometers) at IRF in Kiruna. Riometers measure the absorption of cosmic noise at 30 and 38 MHz and provide information about particles with energies larger than 10 keV. The electron density of the ionosphere is measured by ionosonds and digisondes at IRF in Kiruna.

The Earth’s magnetic field is monitored with magnetometers at Fiby (near Uppsala) and at Abisko. The magnetic field fluctuates rapidly depending on solar activity and slowly depending on variations within the mantle of the Earth. The rapid fluctuations are measured every second by a flux-gate magnetometer and the slow fluctuations twice per month by a proton-precession magnetometer (Table 6, #9.2). Data are archived at World Data Center WDC-C1 in Copenhagen, WDC-C2 in Kyoto, and NGDC in Boulder. The Geological Survey of Sweden (SGU) is responsible for the protonprecession magnetometer measurements.

In and around Kiruna, IRF uses all-sky cameras and other images to detect and record the aurora. The all-sky cameras have 180° field-of-view and take one image per minute. They have been in operation since the International Geophysical Year (IGY) in 1957 (Table 6, #9.1). The Auroral Large Imaging System (ALIS) is a large-scale array of high-resolution monochrome CCD detectors around Kiruna, a network of seven stations within approximately 50 x 50 km. The International Network for Auroral Optical Studies of the Polar Ionosphere, coordinated by IRF, is a forum for planning measuring campaigns, distributing information, and intercalibrating different sets of instruments located in different parts of the world. The network is part of the IPY-endorsed project Heliosphere Impact on Geospace (IPY Cluster #63), with Interhemispheric Conjugacy Effects in Solar-Terrestrial and Aeronomy Research (ICESTAR) and International Heliophysical Year (IHY) as lead projects.

SMHI measures the thickness of the ozone layer at 2 sites in Sweden, one at Norrköping in southeast Sweden and one at Svartberget Forest Research Park, Vindeln, 70 km NW of Umeå. At Svartberget a Dobson and a Brewer Spectrophotometer are operational. The measurements are part of SEPA’s Environmental Monitoring Program.

Organic environmental pollutants in air and precipitation are assessed by the Department of Applied Environmental Sciences (ITM), Stockholm University in a program with 3 sampling sites in Sweden and northern Finland. The analyses include 31 variables, comprised of 12 PAHs, 7 PCBs, 3 DDTs, 3 chlordanes, 2 HCHs, 1 HCB, and 3 PBDEs (Table 4, #1.7).

Deposition measurements are mainly made in forest injury observation plots laid out by the Swedish Forestry Agency (SST). The observations made are: Air Chemistry: SO2, NO2, NH3, O3 Soil Water Chemistry: pH, Alk, SO4-S, Cl, NO3-N, NH4-N, Ca, Mg, Na, K, Mn, Fe, ooAl, oAl, Al-tot, TOC Deposition open field precipitation: H+, SO4-S, Cl, NO3-N, NH4-N, Ca, Mg, Na, K, Mn Deposition in forest throughfall: H+, SO4-S, Cl, NO3-N, NH4-N, Ca, Mg, Na, K, Mn A notorious problem in deposition assessments is dry deposition on forest canopies. If throughfall is sampled below the canopy it will consist not only of dry and wet deposition, but also of canopy leakage, i.e. exudates and diffusion of substances from within the leaves. However, it has been argued that throughfall sampling, even if not free from problems, may add information to the normal wet deposition sampling. IVL operates a throughfall sampling network comprised of 10 forest sites for sampling, from which monthly samples are analyzed for pH, SO4, NO3, NH4, Kjeldahl-N, Cl, K, Ca, Na, Mg, TOC, conductivity, alkalinity, and amount of throughfall.

Calculating deposition in a grid over Sweden showed the lack of information on deposition at high altitude. SMHI applied the meso scale MATCH model to calculate the deposition field and the matched model is called MATCH-Sweden. The result is found at http://www.smhi.se/cmp/jsp/polopoly.jsp?d=5640&l=sv The observations made at these stations are: Particles in air: SO4-S, NO3-N, NH4-N, Cl, Na, Ca, Mg, K Gase:s NH3-N, HNO3-N, SO2-S Deposition open field precipitation: H+, SO4-S, Cl, NO3-N, NH4-N, Ca, Mg, Na, K Deposition in forest throughfall: H+, SO4-S, Cl, NO3-N, NH4-N, Ca, Mg, Na, K To integrate the relatively few deposition measurement sites, SMHI has adopted the Mesoscale Atmospheric Transport and Chemistry Model (MATCH) that uses emission data, meteorological data, routines for chemical processes, and a transport model to calculate long-range transport and deposition of air pollutants (Table 4, #1.5). Time series of gridded data over Sweden for deposition of different inorganic chemical compounds calculated with the MATCH-Sweden model are available at SMHI (Appendix, Table 11). When the MATCH-Sweden model was first tested, the deposition network lacked high elevation sites. Hence, a monitoring program for deposition at higher elevations (Table 4, #1.9) was started. It consists of 4 sites in high elevation forests along the Swedish mountain ridge, where NO3, NH4, NH3, HNO3, SO2, SO4, Na, K, Ca, Mg, Cl, pH, conductivity, and amount of precipitation are analyzed on monthly accumulated precipitation samples.

The subprogram main task is to check if international agreements as the UN Convention on Long Range Transboundary Air Pollution (CLTRAP) are followed. EMEP = European Monitoring and Evaluation Programme. The network comprises 10 stations, out of which three are in northern Sweden. Air chemistry is monitored by diffusion samplers. The following compounds are measured: SO2, SO4, tot-NH4, tot-NO3, soot, NO2, O3 Precipitation quality is monitored by samplers with lid, open only when it rains. The following compounds are measured: SO4-S, NO-N, Cl, NH4-N, Ca, Mg, Na, K, pH, EC. Ozone near ground is analyzed every hour and is part of an European warning system PM10 is particles Metals in air and precipitation is analysed at Bredkälen only. The following elements are analyzed: As, Cd, Co, Cr, Cu, Mn, Ni, Pb, Zn, V, Hg, metyl-Hg.