CPP-01. Bulk and stratified snowpack measurements of internal temperature and density observed in snowpits from the U.S. West; 1992 to present

Abstract
Snowpit records can provide insight into snowpack conditions and changes, but many existing records are still in paper format, making analysis difficult. We digitized 1,807 historical, hand-written snowpit records from across the Rocky Mountains of the Western U.S. This unique record of vertical profiles of temperature and density enables analysis and physical understanding of snowpack cold content (CC) and other snowpack variables. CC represents the energy required to raise the temperature of the snowpack to its melting point (which is related to winter ablation rate and snowmelt onset date). It can be a key indicator of large-scale climate change and is valuable for snow model validation. Digging snowpits and recording vertical profiles of temperature and density from which CC can be calculated is laborious and time-consuming; there are few data collection campaigns and even fewer open-source, large-scale, high-quality data sets. CC processes are poorly understood. For 29 years the USGS Rocky Mountain Regional Snowpack Chemistry Monitoring Study (USGS RMS) has collected snowpit records at a network of 192 sites. The record is updated annually at 60 snowpits (with plans to add another 10 snowpits per year). Here we describe the compilation of this data record, which is already being used to analyze CC and related variables.