Search - NW Climate Science Digest

Use this page to search climate science digests beginning in 2015.

Digests from 2013-2014 are archived here.

Digest Articles

Aquatic Resources, Stream Flow, Hydrology in the Western U.S.

Climate-Aquatics Bonus Blog #60: New report describes data collection protocols for continuous monitoring of temperature & flow in wadeable streams

More stream-climate data is the simplest way to decrease uncertainties…

Avalanche fatalities during atmospheric river events in the western US

Hatchett, B.J., Burak, S., Rutz, J.J., Oakley, N.S., Bair, E.H. and Kaplan, M.L., 2017. Avalanche Fatalities During Atmospheric River Events in the Western United States. Journal of Hydrometeorology. DOI:

A new study led by the Desert Research Institute examined the relationship between atmospheric river occurrence and avalanche fatalities in the western United States from 1998 to 2014. They found atmospheric river conditions to be apparent during or preceding 105 avalanches that resulted in a total of 123 fatalities. Geographical distribution of these fatalities show the highest percentage coinciding with coastal snow avalanche climates, followed by intermountain and then continental snow avalanche climates. Findings from this study show that the intensity of inland water vapor transport could help identify periods of heightened avalanche hazard.

A New Publicly Available Database of Watershed Metrics for the United States

Hill, Ryan A., Marc H. Weber, Scott G. Leibowitz, Anthony R. Olsen, and Darren J. Thornbrugh, 2016.The Stream-Catchment (StreamCat) Dataset: A Database of Watershed Metrics for the Conterminous United States. Journal of the American Water Resources Association (JAWRA) 52(1): 120-128. DOI:10.1111/1752-1688.12372

A new dataset containing landscape metrics for upstream watersheds and catchments in the conterminous United States has been developed by the Environmental Protection Agency’s Office of Research and Development. Called the Stream-Catchment (StreamCat) Dataset, this tool allows the distribution of catchments and watersheds to be visualized for the conterminous United States. The database has been made available to the public which allows researchers and managers to access landscape information without the need for specialized geospatial expertise. The extensive resource will be useful for better understanding and characterizing river systems in the United States. This article, published in the Journal of the American Water Resources Association, detailed the development and main features of the dataset, including specific landscape features used; scripts and algorithms built to produce watershed summaries; and quality assurance procedures for ensuring data consistency.

Temporal patterns and regional variability in 555 years of conterminous U.S. streamflow

Ho, M., Lall, U., Sun, X. and Cook, E.R. In press. Multiscale temporal variability and regional patterns in 555 years of conterminous US streamflow. Water Resources Research, 53. DOI:10.1002/2016WR019632

Scientists from Columbia University reconstructed and characterized streamflow variability at a continental scale using a spatially and temporally complete 555-year-long paleoclimate record of summer droughts. They found decadal-scale variability in the late 1900s in the western U.S., while similar modes of temporal variability were rarely present before the 1950s. The twentieth century featured longer wet spells and shorter dry spells compared with the preceding 450 years, and streamflows in the Pacific Northwest and Northeast are negatively correlated with the central U.S.. These streamflow patterns highlight the potential to mitigate some drought impacts by balancing economic activities and insurance pools across these regions in major droughts.

Nursery Functions of U.S. West Coast Estuaries

Hughes, B.B., M.D., Levey, Brown, J.A., Fountain, M.C.,  Carlisle, A.B., Litvin, S.Y., Greene, C.M., Heady, W.N., Gleason, M.G. 2015. Nursery functions of U.S. west coast estuaries: the state of knowledge for juveniles of focal invertebrates and fish species.

This report synthesizes existing scientific literature, expert opinion, and geospatial data on the presence of juveniles and potential nursery role of West Coast estuaries (in Washington, Oregon, and California) for fifteen ecologically, economically, and culturally important species. This report also evaluated many threats to estuarine habitats (including climate change) and the nursery role they provide to these focal species. 19 threats were analyzed, and habitat loss was the most prevalent threat among the 15 focal species.

Scientists collaborated with Google to map long-term global surface water occurrence

Jean-François Pekel, Andrew Cottam, Noel Gorelick, Alan S. Belward. High-resolution mapping of global surface water and its long-term changes. Nature, 2016; DOI: 10.1038/nature20584

Scientists from the European Commission Joint Research Centre partnered with Google to produce the Global Surface Water Explorer, an interactive map of surface water change from 1984-2015. The tool was created by processing over three million Landsat satellite images and quantifying the data into a 30-meter resolution map. Findings from this dataset were published in Nature and include measured and evident impacts of climate change and climate oscillations on surface water occurrence. Among these findings, the authors emphasize that all continental regions except Oceania show a net increase in permanent surface water, and that areas of water loss are more geographically concentrated around mainly the Middle East and Central Asia. The Global Surface Water Explorer is now free and open to the public.

The Cold-Water Climate Shield: Preserving Salmonid Fishes through the 21st Century

Isaak, D. J., Young, M. K., Nagel, D. E., Horan, D. L. and Groce, M. C. (2015), The cold-water climate shield: delineating refugia for preserving salmonid fishes through the 21st century. Global Change Biology. doi:

Researchers from the Rocky Mountain Research Stations in Montana and Idaho recently published a study in Global Change Biology titled: “The cold-water climate shield: delineating refugia for preserving salmonid fishes through the 21st century.” Researchers identified especially cold habitats capable of absorbing future climate change while still supporting native populations, highlight important salmonid refugia in the western U.S. Through coupling crowd-sourced biological datasets with high-resolution stream temperature scenarios, researchers delineated network refugia across >250,000 stream km in the Northern Rocky Mountains for two native salmonids—bull trout and cutthroat trout. This approach creates a framework to integrate data contributed by many individuals and resource agencies, and a process that strengthens the collaborative and social networks needed to preserve many cold-water fish populations through the 21st century.

Simplifying hydrologic modeling

Markstrom, S.L., Hay, L.E., Clark, M.P. 2016. Towards simplification of hydrologic modeling: identification of dominant processes. Hydrol. Earth Syst. Sci. 20, 4655-4671. doi:10.5194/hess-20-4655-2016

Hydrologic scientists from the United States Geologic Survey underwent a parameter sensitivity analysis of the Precipitation-Runoff Modeling System’s simulation of the conterminous United States. The authors used the parameter sensitivity analysis to identify both the sensitive input parameters and the output variables that were potentially associated with dominant hydrologic processes. The study calibrated sensitivity values of over 100,000 independent units and associated them with hydrologic processes such as snowmelt, surface runoff., infiltration, soil moisture, evapotranspiration, interflow, baseflow, and runoff, as well as model performance statistics such as mean, coefficient of variation and autoregressive lag 1. The authors then used the identified parameters and processes to understand model performance at the location of each unit. Among the findings from this study, the authors highlight that specific performance statistics and output variables have strong influences on parameter sensitivity, and that model complexity can be reduced by focusing on hydrologic processes that are associated with sensitive parameters.

Snow science supporting our nation's water supply

A NASA-led research campaign called SnowEx was recently launched in Colorado. The amount of water in snow plays a critical role in water availability for drinking water, agriculture, and energy, however an accurate measurement of how much water is stored in snow has remained a major obstacle for scientists. The goal of SnowEx is to create and refine the best snow-measuring techniques in order to build an accurate map of water content contained in the nation’s snow. Data collected from SnowEx will be available to the public and stored at the National Snow and Ice Data Center in Boulder, Colorado. Learn more about SnowEx.

Post-fire disturbance impacts on snow hydrology in the Oregon Cascades

Gleason, K.E., Nolin, A.W. 2016. Charred Forests Accelerate Snow Albedo Decay: Parameterizing the Post-Fire Radiative Forcing on Snow for Three Years Following Fire. Hydrologic Processes. 3(11). DOI: 10.1002/hyp.10897.

Hydrologic models of snow-dominated watersheds that have experienced severe forest fires require an understanding of the post-fire disturbance impacts on snow hydrology. Oregon State University scientists Kelly Gleason and Anne Nolin studied the impact of post-fire disturbance on the radiative forcing of snow hydrology in the Oregon Cascades. The authors studied the radiative forcing impacts on in a charred forest of the Oregon Cascades that experienced severe forest fires in 2011. They measured snow albedo (reflectivity), monitored snow and micrometeorological conditions, sampled snow surface debris, and modeled snowpack energy and mass balance in adjacent burned and unburned forest sites. These field measurements showed that charred forests accelerate radiative forcing and advance snow disappearance for several years following fire.