Time-lapse observations of snow bedforms in the Colorado Front Range, 2016-2017

Description: Time-lapse imagery of snow surfaces on Niwot Ridge, in the Colorado Front Range, between March 2016 and April 2017.

Purpose: Videos show the evolution of snow bedforms, including the formation and movement of snow dunes, snow ripples, and sastrugi. Used to analyze the modes of bedform movement, and to constrain the weather conditions in which they form.

Equipment, details + weather data: Time-lapse cameras are Day6 Plotwatcher Pros. They take images every 10s during daylight hours. The cameras are located at -40.054307, -105.590764, 150m upwind of the Niwot Ridge LTER Saddle Station. Bedform movement can thus be correlated with climate and precipitation data from the station, provided at niwot.colorado.edu

Filenames: Files are named yymmddAA.avi, where yy/mm/dd is the date of the recording. When multiple recordings were made in one day, there will be a yymmddAB.avi, yymmddAC.avi, etc. Some filenames are annotated with a description, eg 170226AA-sastrugi.avi. On a few dates (November 2016) the cameras recorded incorrect dates; on these days, the dates in the filenames are to be preferred.

Date and time in video: the date, time and temperature are recorded in the bottom of the videos. The date and time are generally accurate, but if they differ from the date in the filename, that date is to be preferred and the time disregarded. Temperature in the film is generally colder than temperature recorded by the nearby weather station, and we generally disregarded it in favor of climate data from niwot.colorado.edu.

Data format: Data are presented as .avi files, which may be run by most video players. Data were originally recorded with proprietary .tlv file extension. The .tlv format is equivalent to .avi; if any .tlv files are found, simply rename them as .avi files and play as usual.

Acknowledgements: This research was supported by a Department of Energy Computational Science Graduate Fellowship (DE-FG02-97ER25308), by a University of Colorado Chancellor's Fellowship, and by the National Science Foundation via support for the Boulder Creek Critical Zone Observatory (EAR-1331828).
Field equipment was funded by the American Alpine Club; the Colorado Scientific Society; and a Patterson Award from the University of Colorado Department of Geological Sciences. Field assistants were funded by the University of Colorado Undergraduate Research Opportunities Program. Logistical support and climate data were provided by the NSF-supported Niwot Ridge Long-Term Ecological Research Project and the University of Colorado Mountain Research station.