Impact of Atmospheric Rivers on Surface Hydrological Processes in Western U.S. Watersheds
Abstract
Atmospheric rivers (ARs) can significantly modulate surface hydrological processes through the extreme precipitation they produce. However, there is a lack of comprehensive evaluation of ARs' impact on surface hydrology. This study uses a high‐resolution regional climate simulation to quantify the impact of ARs on surface hydrological processes across the western U.S. watersheds. The model performance is evaluated through extensive comparison against observations. Our analysis indicates that ARs produce heavy precipitation but suppress evapotranspiration. Snowpack ablates more during ARs, with higher air temperature and increased longwave radiation playing the primary and secondary roles, respectively. At the 0 °C to 10 °C temperature range, ARs increase the probability of snow ablation from 0.33 to 0.57. The runoff‐to‐precipitation ratio is primarily controlled by antecedent soil moisture, but it almost doubles in the northwestern watersheds due to the intensification of snow ablation during AR events. From the analysis of the relationship between the hydrological responses and different meteorological factors, precipitation, temperature, and radiation are identified as the key drivers that distinguish the hydrologic responses between AR and non‐AR events. Lastly, analysis of ARs and total runoff at annual scale and 1 April snowpack and winter precipitation shows that ARs explain 30% to 60% of the variability of annual total runoff and sharpen the seasonality of water resources availability in the west coast mountain watersheds.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Aug 17, 2019
- Source ID
- 10.1029/2019jd030468
Entities
People
- L. Ruby Leung
- Mark S. Wigmosta
- Marshall Richmond
- Xiaodong Chen
Organizations
- Pacific Northwest National Laboratory
- Strategic Environmental Research and Development Program
- United States Department of Energy