Snow Water Equivalence:
Layer measurement method: Water is stored in the form of snow. The amount of H2O in the snow pack may change over time. Snow may be released to the atmosphere through sublimation. Snow may also melt and run off or be absorbed by the ground. The amount of water stored as snow is an important measure. Measuring the density of the snow pack either layer by layer or across the entire snow pack, provides an equivalent to the amount of water stored in the snow pack. For example: The weight of 100 ml of snow is compared to the weight of 100 ml of water which is equal to 100 gm. This pro- vides a water equivalent. Measurements using the 100 ml plastic container are made by pushing the container into the layer. After the container has been pressed into the layer, use a flat surface to cover the open surface while it is still in the snow layer. Remove the container and trim the ends so that the core is flush. Weigh the 100 ml snow core and container with the spring scale. Subtract the container weight from this to find the weight of the snow core. Calculate snow density by dividing the weight of snow core (g) by 100 ml (the core volume).
Single measurement method: Another method is to use a stove pipe section to capture a cross section of the snow pack. Insert the stove pipe into the snow pack. Push a clip board under the stove pipe while it is in the snow pack. Keeping the snow captured, dump the contents into a plastic bag (i.e. garbage bag). Record the depth of the snow pack at the sample point. Calculate the volume of snow in the stove pipe. Weigh the garbage bag with snow and then subtract the weight of the bag to get the weight of the snow column. Calculate snow density by dividing the snow weight by the volume of the pipe. Snow density and water equivalent are the same.
Layer measurement method: Water is stored in the form of snow. The amount of H2O in the snow pack may change over time. Snow may be released to the atmosphere through sublimation. Snow may also melt and run off or be absorbed by the ground. The amount of water stored as snow is an important measure. Measuring the density of the snow pack either layer by layer or across the entire snow pack, provides an equivalent to the amount of water stored in the snow pack. For example: The weight of 100 ml of snow is compared to the weight of 100 ml of water which is equal to 100 gm. This pro- vides a water equivalent. Measurements using the 100 ml plastic container are made by pushing the container into the layer. After the container has been pressed into the layer, use a flat surface to cover the open surface while it is still in the snow layer. Remove the container and trim the ends so that the core is flush. Weigh the 100 ml snow core and container with the spring scale. Subtract the container weight from this to find the weight of the snow core. Calculate snow density by dividing the weight of snow core (g) by 100 ml (the core volume).
Single measurement method: Another method is to use a stove pipe section to capture a cross section of the snow pack. Insert the stove pipe into the snow pack. Push a clip board under the stove pipe while it is in the snow pack. Keeping the snow captured, dump the contents into a plastic bag (i.e. garbage bag). Record the depth of the snow pack at the sample point. Calculate the volume of snow in the stove pipe. Weigh the garbage bag with snow and then subtract the weight of the bag to get the weight of the snow column. Calculate snow density by dividing the snow weight by the volume of the pipe. Snow density and water equivalent are the same.