TVCSnow 2017-2018 tundra snow depth probe measurements

A total of 13,263 snow depth measurements were collected in an open tundra environment between March 16th and 23rd 2018. Survey transects of several hundred meters were measured along predefined airborne flight lines, optical aerial drone survey areas and adjacent to excavated snow pits/ground-based radiometer sites where manual and automated in situ snow measurements of density, specific surface area, snow grain and layering characteristics were recorded. The snow depth measurements were recorded using magnaprobes that can measure both depth and position simultaneously, patented in 1999 (United States Patent 5,864,059, 1999) and produced commercially by Snow‐Hydro LLC. The nature of the substrate beneath the snow controls the snow depth vertical accuracy with errors ranging from near zero for hard bases to +5 cm of over-probe in soft vegetation and the horizontal positional accuracy is typically ±2.5 m using the onboard Wide Area Augmentation System‐enabled GPS (Sturm and Holmgren, 2018). A 2018 experiment within the same study region (unpublished) examined the level of over-probe in and around a single snow pit, documenting an average over-probe penetration of 7.6 cm (n=68). All magna probe depths have undergone quality control with erroneous values removed. The depths have been organized into a comma de-limited file with six columns of information. 1. TimeStamp: This is the GPS time stamp recorded simultaneously with the snow depth measurement in Coordinated Universal Time (UTC). Formatted as: m/d/yyyy h:mm 2. Counter: this is the counter of the number of depths recorded since the unit was powered on. This provides an indication of the sequential order that the depths were recorded by a specific magnaprobe unit (multiple units were used during each campaign)at a particular site only. 3. DepthCm: This is the measured snow depth in centimetres 4. Latitude: This is the latitude measured in decimal degrees to six decimal places (WGS84) 5. Longitutde: This is the longitutde measured in decimal degrees to six decimal places (WGS84) 6. Site: Each magna probe depth is associated with a Site ID to be used to link to other in situ snow survey measurements and aerial drone imagery/snow depth estimates recorded in close proximity. References: Sturm M, Holmgren J. 2018. An automatic snow depth probe for field validation campaigns. Water Resources Research. 54: 9695-9701. https://doi.org/10.1029/2018WR023559