Earth and Atmospheric Sciences, Department of
First Advisor
Dr. Mark Anderson
Date of this Version
Fall 12-11-2019
Citation
Jones, C., 2019: A Climatology of Snowpack in the Southern Rocky Mountains and Snow to Liquid Ratio Forecasting Techniques Using Model Generated Soundings from the Rapid Refresh Model. M.S. thesis, Dept. of Earth and Atmospheric Sciences, University of Nebraska, 59 pp.
Abstract
Mountainous snowpack represents up to 70% of the total water resources for areas in the western United States. Temperature and precipitation control the accumulation and ablation of the snowpack throughout the cold season, both of which are subject to a changing climate. This study will use a network of snow telemetry (SNOTEL) stations to investigate changes in the snowpack season, snow water equivalent (SWE), and temperature in the southern Rocky Mountain region. Additionally, this study will use model generated soundings from the Rapid Refresh (RAP) model to establish relationships between the depth and cloud proportion of ice crystal growth layers, and the SNOTEL measured snow-to-liquid ratio (SLR). Results indicate that mountain ranges within northern New Mexico and southern Colorado have measured a statistically significant decrease in the length of the snowpack accumulation season, an earlier date and lessened magnitude of maximum SWE, and shortened overall snowpack season length. Northern mountain ranges within the study region also measured a decrease, although to less of an areal extent than ranges in the south. The majority of SNOTEL stations throughout the region measured an increase in both the number and percentage of days with maximum temperatures above 0 °C. Results from the SLR analysis indicate a higher proportion of the cloud with temperatures colder than -12 °C tended to have higher SLR than those with a high cloud proportion in warmer temperatures. Analysis of the depth of the ice crystal growth layers showed little differentiation in measured SLRs due to the confines of observed lapse rates within snowstorms. Additionally, average and high SLRs were more common with the presence of the dendritic growth layer within the cloud.
Advisor: Mark R. Anderson
Comments
A THESIS Presented to the Faculty of The Graduate College at the University of Nebraska In Partial Fulfillment of Requirements For the Degree of Master of Science, Major: Earth and Atmospheric Sciences, Under the Supervision of Professor Mark R. Anderson. Lincoln, Nebraska: December 2019
Copyright 2019 Carson M. Jones