Vegetation and meteorological observations (snow and radiation) were collected by various ground instruments in an area of forest near Sodankyla (Finalnd) during measurement campaigns in March 2011. This data is made available through the BADC. An open area and five 20 m × 20 m forest plots were selected for shortwave and longwave radiation measurements and canopy characterization. The Arctic Research Centre of the Finnish Meteorological Institute at Sodankylä (67°22'N, 26°38'E) has continuous weather observations dating back to 1908 and is a major centre for meteorological and remote sensing field studies. The surrounding area includes forests of Norway Spruce (Picea abies) and Scots Pine (Pinus sylvestris), extensive mires and numerous lakes that are frozen and snow-covered in winter. This was a NERC funded project.

Vegetation and meteorological observations (snow and radiation) were collected by various ground instruments in an area of forest near Abisko (Sweden) and Sodankylä (Finland) during measurement campaigns in March 2011 and March 2012. This dataset contains the snow depth data collected at Sodankyla site in March 2011. Snow depths were measured by pushing a graduated probe down to the ground surface at points with 2 m spacing in each 20 m × 20 m plot, giving grids of 121 points. This was a NERC funded project.

Vegetation and meteorological observations (snow and radiation) were collected by various ground instruments in an area of forest near Abisko (Sweden) and Sodankylä (Finland) during measurement campaigns in March 2011 and March 2012. This dataset contains the snow depth data collected at Abisko site in March 2011. Snow depths were measured by pushing a graduated probe down to the ground surface at points with 2 m spacing in each 20 m × 20 m plot, giving grids of 121 points. This was a NERC funded project.

Vegetation and meteorological observations (snow and radiation) were collected by various ground instruments in an area of forest near Abisko (Sweden) and Sodankylä (Finland) during measurement campaigns in March 2011 and March 2012. This dataset contains the radiation data collected at Abisko site in March 2011. Above-canopy radiation: An open area was selected at each study site (“plot O”) for measurements assumed to be representative of incoming radiation above the nearby forest canopy. A Delta-T Devices BF3 sunshine sensor and a Kipp & Zonen CGR3 pyrgeometer were connected to a Campbell Scientific CR1000 data logger recording 5-minute averages of measurements made every 5 seconds. The BF3 measures total and diffuse incoming shortwave radiation, and the CGR3 measures thermal longwave radiation. Below-canopy radiation: In the forest plots, two arrays of ten Kipp & Zonen CM3 shortwave pyranometers and four Kipp & Zonen CGR3 longwave pyrgeometers were connected to AM16/32B multiplexers and Campbell Scientific CR1000 data loggers recording 5-minute averages of measurements made every 5 seconds. One array was set up in a “continuity plot” C for the entire duration of each field campaign, while the other array was moved between four “roving plots” R1 to R4, providing at least 5 complete days of data at each plot. All radiometers were placed on small plywood platforms on the snow surface and were levelled and cleared of snow every morning. Radiometer positions were recorded using differential GPS at Abisko and averages of repeated handheld GPS measurements at Sodankylä. This was a NERC funded project.

The GlobSnow SWE product is the first satellite based daily SWE dataset for the non-alpine northern hemisphere that extends from 1979 to 2014. The previous existing daily SWE records have spanned a shorter time period (2002-2014) or described the snow conditions on a monthly basis for a similar period (1978-2014). The GlobSnow SWE record utilizes a novel data-assimilation based approach for SWE estimation which combines weather station measurements of snow depth with satellite passive microwave measurements. This approach was shown to be superior to alternative algorithms which solely utilize satellite data through comparison with extensive ground reference datasets. The GlobSnow-1 and -2 projects have developed a long term data record of SWE products covering the non-alpine Northern Hemisphere, based on a time series of remotely sensed observations from the Nimbus-7 SMMR, DMSP F8/F11/F13/F17 SSM/I(S) instruments and ground-based weather station measurements from 1979 until 2014. There are three SWE products (all on the EASE model grid; see Armstrong and Brodzik, 1995): - Daily Snow Water Equivalent (Daily L3A SWE), snow water equivalent (mm) for each grid cell for all evaluated land areas of the Northern Hemisphere. - Weekly Aggregated Snow Water Equivalent (Weekly L3B SWE), calculated for each day based on a 7-day sliding time window aggregation of the daily SWE product. - Monthly Aggregated Snow Water Equivalent (Monthly L3B SWE), a single product for each calendar month, providing the average and maximum SWE, calculated from the weekly aggregated SWE product. The GlobSnow-1 project resulted in two versions of the data record, SWE v1.0 and SWE v1.3 (available from FMI). The dataset produced in GlobSnow-2 is identified as the GlobSnow SWE v2.0 data record. In addition to the SWE retrievals, the SWE products include information on the overall extent of snow cover. The information on snow extent is included in the product by utilizing the following coding for the SWE product, whereby SWE values of: - 0 mm denotes snow-free areas (Snow Extent 0%) - 0.001 mm denote areas with melting snow (Snow Extent undefined between 0% and 100%; no SWE retrieval because of the wet state of the snow cover) - > 0.001 mm denote areas with full snow cover (Snow Extent 100%) The areas that have been flagged as snow-free or melted are identified using a time-series melt detection approach described in Takala et al. (2009). The areas that are identified as wet snow or have no SWE retrieval, but are identified as snow covered with the time-series melt-detection approach, are denoted with a SWE value of 0.001 mm. The areas that are determined as snow-free or melted by the melt-detection approach, are denoted with a SWE value of 0 mm. All the other areas show a retrieved SWE value (that is in all cases greater than 0.001 mm). The project was coordinated by the Finnish Meteorological Institute (FMI). Other project partners involved are NR (Norwegian Computing Centre), ENVEO IT GmbH, GAMMA Remote Sensing AG, Finnish Environment Institute (SYKE), Environment Canada (EC), Northern Research Institute (Norut), University of Bern, Meteoswiss and ZAMG.

This dataset contains Global Precipitation Measurements (GPM) Integrated Multi-satellitE Retrievals (IMERG) v5 and v6. The Global Precipitation Measurement (GPM) mission is an international network of satellites that provide the next-generation global observations of rain and snow.

Vegetation and meteorological observations (snow and radiation) were collected by various ground instruments in an area of forest near Abisko (Sweden) and Sodankylä (Finland) during measurement campaigns in March 2011 and March 2012. This dataset contains the hemispherical photography data collected at Sodankyla site in March 2011. Upward-looking hemispherical photographs were taken at every radiometer position using a Nikon Coolpix 4300 digital camera with a Nikon FC-E8 fisheye lens. The camera was mounted on a small tripod with the lens approximately 20 cm above the snow surface. In each case, the camera was levelled and rotated such that magnetic north is at the top of the photograph. This was a NERC funded project.

This dataset includes the CNRM-CM5 model output prepared for SPECS snowInit (1991-2012). These data were prepared by the Centre National de Recherches Meteorologiques, as part of the SPECS project. Model id is CNRM-CM5, frequency is daily, associated model is atmo HR ocean HR. Arpege V5.1 is the underlying model, 31 vertical levels (CNRM-CM5 2013 atmosphere:Arpege (tl127l91r); ocean:Nemo (Orca1); sea-ice:Gelato; land:isba. Atmospheric variables are: hfls hfss pr psl rlds rls rsds rss ta tas tasmax tasmin zg

Vegetation and meteorological observations (snow and radiation) were collected by various ground instruments in an area of forest near Abisko (Sweden) and Sodankylä (Finland) during measurement campaigns in March 2011 and March 2012. This dataset contains the radiation data collected at Abisko site in March 2011. Above-canopy radiation: An open area was selected at each study site (“plot O”) for measurements assumed to be representative of incoming radiation above the nearby forest canopy. A Delta-T Devices BF3 sunshine sensor and a Kipp & Zonen CGR3 pyrgeometer were connected to a Campbell Scientific CR1000 data logger recording 5-minute averages of measurements made every 5 seconds. The BF3 measures total and diffuse incoming shortwave radiation, and the CGR3 measures thermal longwave radiation. Below-canopy radiation: In the forest plots, two arrays of ten Kipp & Zonen CM3 shortwave pyranometers and four Kipp & Zonen CGR3 longwave pyrgeometers were connected to AM16/32B multiplexers and Campbell Scientific CR1000 data loggers recording 5-minute averages of measurements made every 5 seconds. One array was set up in a “continuity plot” C for the entire duration of each field campaign, while the other array was moved between four “roving plots” R1 to R4, providing at least 5 complete days of data at each plot. All radiometers were placed on small plywood platforms on the snow surface and were levelled and cleared of snow every morning. Radiometer positions were recorded using differential GPS at Abisko and averages of repeated handheld GPS measurements at Sodankylä. This was a NERC funded project.

Vegetation and meteorological observations (snow and radiation) were collected by various ground instruments in an area of forest near Abisko (Sweden) and Sodankylä (Finland) during measurement campaigns in March 2011 and March 2012. This dataset contains the hemispherical photography data collected at Abisko site in March 2011. Upward-looking hemispherical photographs were taken at every radiometer position using a Nikon Coolpix 4300 digital camera with a Nikon FC-E8 fisheye lens. The camera was mounted on a small tripod with the lens approximately 20 cm above the snow surface. In each case, the camera was levelled and rotated such that magnetic north is at the top of the photograph. This was a NERC funded project.