A collection of in situ manual and automated (snow pillow) SWE observations from Finland, Canada and Russia collected in the ERA-CLIM-2 project. Data coverage is shown on the map. The average value for each snow course is provided. Measurements from 1935 to 2014 are available. The exact measurement protocol varies between Finland, Russia and Canada. The length of the snow course varies, as does the distance between manual SWE measurements. In closed forests in Russia, the length of the snow survey is 500 m with snow depth measured at 10 m intervals, and snow density every 100 m. In open canopy forested regions the length of the snow survey is 1 km, while in steppes the length of the snow survey is 2 km. For both of these land cover types, snow depth is measured every 20 m, and snow density at 200 m intervals (sometimes every 100 m). Measured snow depth and snow density were averaged along the path, and water equivalent calculated as SWE = 10dh (mm), where d = density (g/cm3) and h = depth (cm). In Finland, the procedure is similar to Russia. A snow course is from 2 to 4 km long and each course is measured once or twice a month. Snow depth is measured every 100 m and density every 500 m. The courses in Canada are shorter, typically 5-40 samples of snow depth and density.
