Biological and Environmental Research - Earth and Environmental System Sciences
Earth and Environmental System Modeling

A Framework to Delineate Precipitation‐Runoff Regimes: Precipitation Versus Snowpack in the Western United States

TitleA Framework to Delineate Precipitation‐Runoff Regimes: Precipitation Versus Snowpack in the Western United States
Publication TypeJournal Article
Year of Publication2019
JournalGeophysical Research Letters
Volume46
Number22
Pages13044-13053
Abstract / Summary

Snowpack accumulation/ablation affects the runoff response to precipitation by modulating the water flux reaching the surface. Previous studies mostly focused on “rain‐on‐snow” events. Here we propose a framework to extend the scope and classify precipitation events accompanied by snow accumulation/ablation (precipitation‐and‐snow, or PAS, events) into five regimes. This framework is applied to a regional climate simulation over the western United States for 1981–2015 to reveal regions where daily changes in snowpack alter the surface hydrologic responses to precipitation. Over the western United States, PAS events account for 50–90% of all the precipitation events. Compared to the broad spatial distribution of snow accumulation‐type PAS events, snowmelting‐type PAS events are limited to coastal high‐elevation areas. Atmospheric rivers, a key driver of heavy precipitation in the region, account for only 2% of the PAS events, but they trigger significant snowmelt, accounting for 20% and 11% of light and heavy snowmelting events, respectively.

URLhttp://dx.doi.org/10.1029/2019gl085184
DOI10.1029/2019gl085184
Journal: Geophysical Research Letters
Year of Publication: 2019
Volume: 46
Number: 22
Pages: 13044-13053
Publication Date: 11/2019

Snowpack accumulation/ablation affects the runoff response to precipitation by modulating the water flux reaching the surface. Previous studies mostly focused on “rain‐on‐snow” events. Here we propose a framework to extend the scope and classify precipitation events accompanied by snow accumulation/ablation (precipitation‐and‐snow, or PAS, events) into five regimes. This framework is applied to a regional climate simulation over the western United States for 1981–2015 to reveal regions where daily changes in snowpack alter the surface hydrologic responses to precipitation. Over the western United States, PAS events account for 50–90% of all the precipitation events. Compared to the broad spatial distribution of snow accumulation‐type PAS events, snowmelting‐type PAS events are limited to coastal high‐elevation areas. Atmospheric rivers, a key driver of heavy precipitation in the region, account for only 2% of the PAS events, but they trigger significant snowmelt, accounting for 20% and 11% of light and heavy snowmelting events, respectively.

DOI: 10.1029/2019gl085184
Citation:
Chen, X, Z Duan, L Leung, and M Wigmosta.  2019.  "A Framework to Delineate Precipitation‐Runoff Regimes: Precipitation Versus Snowpack in the Western United States."  Geophysical Research Letters 46(22): 13044-13053.  https://doi.org/10.1029/2019gl085184.