Changes in Mechanisms and Characteristics of Western U.S. Floods Over the Last Sixty Years

Huang, Huilin; Fischella, M.; Liu, Yufei; Ban, Zhaoxin; Fayne, Jessica V.; Li, Dongyue; Cavanaugh, Kyle C.; Lettenmaier, Dennis P.

doi:10.1029/2021gl097022

Cited by 26 publications

(18 citation statements)

References 114 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Despite the impact natural variability can have, this influence has not been considered when evaluating historical flood hazard trends (e.g., Huang et al., 2022). Natural variability may shape warming trends, influence extreme precipitation, and impact antecedent soil moisture conditions, all of which can influence extreme streamflow.…”

Section: Introductionmentioning

confidence: 99%

Natural Variability Has Concealed Increases in Western US Flood Hazard Since the 1970s

Bass

Norris

Thackeray

et al. 2022

Geophysical Research Letters

View full text Add to dashboard Cite

Flood hazard across the western United States (US) has generally shown decreasing trends in recent decades. This region's extreme streamflow is highly influenced by natural variability, which could either mask or amplify anthropogenic streamflow trends. In this study, we utilize a technique known as dynamical adjustment to assess historical (1970–2020) annual maximum 1‐day streamflow (Qx1d) from unregulated basins across the western US with and without the impact of natural variability. After removing natural variability, the fraction of basins with a positive (>5%) trend in Qx1d shifts from 25% to 53%. Basins with increasing (decreasing) Qx1d trends after dynamical adjustment exhibit weak (strong) drying, and furthermore are associated with intensifying precipitation extremes and/or large decreases in snowpack. Increasing flood hazard will likely emerge for such basins as the current phase of natural decadal variability shifts, and anthropogenic signals continue to intensify.

show abstract

Section: Introductionmentioning

confidence: 99%

Natural Variability Has Concealed Increases in Western US Flood Hazard Since the 1970s

Bass

Norris

Thackeray

et al. 2022

Geophysical Research Letters

View full text Add to dashboard Cite

show abstract

“…Due to LAPs and albedo feedbacks, runoff increases first and decreases in the late melting season. As floods in the Sierra Nevada basins are mainly produced by snowmelt (Huang et al., 2022 ), the early shift of snowmelt timing is expected to shift snowmelt‐driven peak runoff date to earlier by about 5 days.…”

Section: Resultsmentioning

confidence: 99%

Snow Albedo Feedbacks Enhance Snow Impurity‐Induced Radiative Forcing in the Sierra Nevada

Huang

Qian

et al. 2022

Geophysical Research Letters

Self Cite

View full text Add to dashboard Cite

This study employs a fully coupled meteorology‐chemistry‐snow model to investigate the impacts of light‐absorbing particles (LAPs) on snow darkening in the Sierra Nevada. After comprehensive evaluation with spatially and temporally complete satellite retrievals, the model shows that LAPs in snow reduce snow albedo by 0.013 (0–0.045) in the Sierra Nevada during the ablation season (April‐July), producing a midday mean radiative forcing of 4.5 W m−2 which increases to 15–22 W m−2 in July. LAPs in snow accelerate snow aging processes and reduce snow cover fraction, which doubles the albedo change and radiative forcing caused by LAPs. The impurity‐induced snow darkening effects decrease snow water equivalent and snow depth by 20 and 70 mm in June in the Sierra Nevada bighorn sheep habitat. The earlier snowmelt reduces root‐zone soil water content by 20%, deteriorating the forage productivity and playing a negative role in the survival of bighorn sheep.

show abstract

“…The elevated dust emission and earlier dust season are supposed to lead to a spectrum of environmental and societal impacts in the most populated US state. In particular, the resultant dust deposition on mountain snow decreases snow albedo and produces a radiation forcing of 0-14.6 W m −2 during the melting season (Huang et al, 2022a), shifting snowmelt timing to earlier dates and further increasing California's vulnerability to water resource fluctuations (Wu et al, 2018;Huang et al, 2022b). With its complex terrains, frequently varying microclimate, and coexisting sources from both local and remote regions, the Sierra Nevada area is an interesting region for studying dust transport and its response to climate change.…”

Section: Introductionmentioning

confidence: 99%

Where does the dust deposited over the Sierra Nevada snow come from?

et al. 2022

Self Cite

View full text Add to dashboard Cite

Abstract. Mineral dust contributes up to one-half of surface aerosol loading in spring over the southwestern United States, posing an environmental challenge that threatens human health and the ecosystem. Using self-organizing map (SOM) analysis with dust deposition and flux data from WRF-Chem and Modern-Era Retrospective analysis for Research and Applications, Version 2 (MERRA-2), we identify four typical dust transport patterns across the Sierra Nevada, associated with the mesoscale winds, Sierra barrier jet (SBJ), North Pacific High (NPH), and long-range cross-Pacific westerlies, respectively. We find that dust emitted from the Central Valley is persistently transported eastward, while dust from the Mojave Desert and Great Basin influences the Sierra Nevada during mesoscale transport occurring mostly in winter and early spring. Asian dust reaching the mountain range comes either from the west through straight isobars (cross-Pacific transport) or from the north in the presence of the NPH. Extensive dust depositions are found on the west slope of the mountain, contributed by Central Valley emissions and cross-Pacific remote transport. In particular, the SBJ-related transport produces deposition through landfalling atmospheric rivers, whose frequency might increase in a warming climate.

show abstract

Changes in Mechanisms and Characteristics of Western U.S. Floods Over the Last Sixty Years

Cited by 26 publications

References 114 publications

Natural Variability Has Concealed Increases in Western US Flood Hazard Since the 1970s

Natural Variability Has Concealed Increases in Western US Flood Hazard Since the 1970s

Snow Albedo Feedbacks Enhance Snow Impurity‐Induced Radiative Forcing in the Sierra Nevada

Where does the dust deposited over the Sierra Nevada snow come from?

Contact Info

Product

Resources

About