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

Impact of Atmospheric Rivers on Surface Hydrological Processes in Western U.S. Watersheds

TitleImpact of Atmospheric Rivers on Surface Hydrological Processes in Western U.S. Watersheds
Publication TypeJournal Article
Year of Publication2019
JournalJournal of Geophysical Research: Atmospheres
Volume124
Number16
Pages8896-8916
Abstract / Summary

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.

URLhttp://dx.doi.org/10.1029/2019jd030468
DOI10.1029/2019jd030468
Journal: Journal of Geophysical Research: Atmospheres
Year of Publication: 2019
Volume: 124
Number: 16
Pages: 8896-8916
Publication Date: 08/2019

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.

DOI: 10.1029/2019jd030468
Citation:
Chen, X, L Leung, M Wigmosta, and M Richmond.  2019.  "Impact of Atmospheric Rivers on Surface Hydrological Processes in Western U.S. Watersheds."  Journal of Geophysical Research: Atmospheres 124(16): 8896-8916.  https://doi.org/10.1029/2019jd030468.