NW Climate Science Digest

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

Special issue of Northwest Science devoted to climate change impacts on the Skagit River Basin

Rybczyk, JM, Hamlet AF, MacIlroy C, Wasserman L (2016) Introduction to the Skagit Issue - From Glaciers to Estuary: Assessing Climate Change Impacts on the Skagit River Basin. Northwest Science 90(1): 1-4. Doi: 10.3955/046.090.0102

Riedel JL and Larrabee MA (2016). Impact of recent glacial recession on summer streamflow in the Skagit River. Northwest Science 90(1): 5-22. Doi: 10.3955/046.090.0103

Lee S-Y, Hamlet AF, Grossman EE (2016) Impacts of climate change on regulated streamflow, hydrologic extremes, hydropower production, and sediment discharge in the Skagit River Basin. Northwest Science 90(1): 23-43. Doi: 10.3955/046.090.0104

Stumbaugh M and Hamlet AF (2016) Effects of climate change on extreme low-flows in small lowland tributaries in the Skagit River Basin. Northwest Science 90(1): 44-56. Doi: 10.3955/046.090.0105

Hamman JJ, Hamlet AF, Lee S-Y, Fuller R, Grossman EE (2016) Combined effects of projected sea level rise, storm surge and peak river flows on water levels in the Skagit floodplain. Northwest Science 90(1): 57-78. Doi: 10.3955/046.090.0106

Hood WG, Grossman EE, Veldhuisen C (2016) Assessing tidal marsh vulnerability to sea-level rise in the Skagit Delta. Northwest Science 90(1): 79-93. Doi: 10.3955/046.090.0107

A new issue of the journal Northwest Science is devoted to assessing climate change impacts on the Skagit River Basin in Washington. The issue features articles by scientists from across the Pacific Northwest as well as Larry Wasserman, Environmental Policy Director of the Swinomish Indian Tribal Community. The Skagit is responsible for over 30% of freshwater entering Puget Sound and is one of the most important sources of water in Western Washington. It is also home to all six salmon species that can be found in Puget Sound, which includes steelhead and Chinook salmon. Previous research studies have found that the Skagit basin is particularly vulnerable to climate change. There are approximately 394 glaciers in the eastern headwaters of the Skagit, and these glaciers are being affected by warming temperatures. Projected decreases in snowpack are expected to affect aquatic ecosystems, water supply and hydropower production. Fluvial processes, such as flow and sediment transport, are expected to shift and profoundly affect cold-water fish species, such as salmon, as well as leading to sea level rise via coastal flooding and erosion. Articles in the special issue discuss these issues affecting the Skagit River Basin, including articles on 1) impacts of glacial recession on summer streamflow, 2) impacts on hydrologic extremes, hydropower and sediment discharge, 3) low-flows in small lowland tributaries, 4) effects of sea level rise and storm surge on water levels, 4) vulnerability of tidal marshes to sea level rise, and 5) sensitivity of estuarine circulation to sea level rise.

First EPA National Wetland Assessment

The EPA has released its first ever nationwide report on the health of U.S. wetlands, finding that one-third of them are in poor condition. The report measured the biological, physical, and chemical stresses acting upon U.S. coastal marshes, prairie potholes, central plain meadows, and other natural areas encompassed by the definition of ‘wetland’. Concerning wetlands in the Western U.S., the report found that 72% have high or very high levels of stress from nonnative plants. Additionally, relative to the rest of the country, many wetland areas in the western U.S. tested high on the index for contamination of heavy metals. Read the full National Wetland Condition Assessment using the link below.

Five centuries of U.S. west coast drought

Wise, E. K. (2016), Five centuries of U.S. West Coast drought: Occurrence, spatial distribution, and associated atmospheric circulation patterns, Geophys. Res. Lett., 43, 4539–4546, doi:10.1002/2016GL068487.

The drought along the west coast of the U.S. that began in 2012 formed in relation to a high-pressure ridge linked to internal atmospheric variability. In this recently published study, University of North Carolina scientist Erika Wise examined this most recent drought (the occurrence, spatial patterns, and associated circulation features) through a paleoclimate context by linking atmospheric circulation to surface hydroclimate patterns. Spatial reconstructions of upper atmosphere pressure patterns and cool-season drought showed that drought along the U.S. west coast has occurred periodically since 1500 C.E. These droughts were also found to be associated with a strong ridge centered along the Pacific Northwest coast.

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.

Biodiversity/Species and Ecosystem Response

How biodiversity buffers fisheries against climate change

Duffy, J.E., Lefcheck, J.S., Stuart-Smith, R.D., Navarrete, S.A., Edgar, G.J. 2016. Biodiversity enhances reef fish biomass and resistance to climate change. Proceedings of the National Academy of Sciences. doi: 10.1073/pnas.1524465113

An international team of researchers used data collected by citizen scientist SCUBA divers at nearly 2,000 sites around the world to investigate relationships between biodiversity and biomass. They found that warmer water temperatures increase biomass, but temperature variability decreases it. They also found that sites with greater species richness and diversity had higher biomass, and that species diversity was the second strongest predictor of biomass. Analysis showed that, while changing temperatures did reduce reef fish biomass, the effect was halved in the most diverse ecosystems. That’s “possibly because species-rich communities harbor fishes with a range in thermal niches,” speculate the authors. More biodiverse ecosystems are simply more likely to include fish species able to withstand the coming changes. The study underscores the fact that conserving individually important species is not enough. Instead, the primary target of marine conservation should be biodiversity. Indeed, the researchers concluded, “biodiversity is equally and often more important than water quality, nutrient supply, and human influence in controlling the global distribution of reef fish biomass.” Conservation efforts that have biodiversity as a goal will therefore be best able to ensure the continued availability of fish as a key source of human nutrition.

Squid are thriving while fish decline

Zoë A. Doubleday, Thomas A.A. Prowse, Alexander Arkhipkin, Graham J. Pierce, Jayson Semmens, Michael Steer, Stephen C. Leporati, Sílvia Lourenço, Antoni Quetglas, Warwick Sauer, Bronwyn M. Gillanders. 2016. Global proliferation of cephalopods. Current Biology (26) 10. DOI: http://dx.doi.org/10.1016/j.cub.2016.04.002

This study represents the first global-scale database of cephalopod population numbers from 1953 to 2013. The authors compiled historical catch rates for 35 species from all over the world and found consistent increases across the three cephalopod groups in all habitat types, from open ocean to tidepools. These results contrast starkly with population patterns in marine vertebrates, many of which declined by nearly half from 1970 to 2012. The authors are currently investigating potential causes of the increase in cephalopods, but suspect that climate change and overfishing may play a role. Warming oceans, while detrimental to some fish, may create beneficial growing conditions for some cephalopods, and overfishing could potentially reduce cephalopod predators.

One third of north american birds at risk of extinction due to human activity and climate change

The North American Bird Conservation Initiative’s latest “State of the Birds” report finds that more than one-third of North America’s 1,154 native bird species are at high risk of extinction due to climate change and other manmade factors. Thirty-seven percent of the continent’s bird species across 10 different habitat types need “urgent conservation action.” Forty-nine percent were identified as having moderate risk, while just 14 percent were marked as low risk. Researchers categorized bird species based on their population size, population trends, population distribution and threats to both breeding and non-breeding members of the species. The decline of bird species is most pronounced in ocean habitats, where 57 percent were identified as having a high risk of extinction and are on the organization’s “Watch List.” The authors point out that western temperate forest birds are of higher conservation concern, due to smaller ranges and populations, than eastern forest birds.

Climate and Weather Reports and Services

Rainfall generates a new source of airborne organic particles

Wang, B., Harder, T. H., Kelly, S. T., Piens, D. S., China, S., Kovarik, L., Keiluweit, M.  Arey, B.W., Gilles, M.K., Laskin, A. (2016). Airborne soil organic particles generated by precipitation. Nature Geoscience. doi:10.1038/ngeo2705.

Scientists from the Pacific Northwest National Laboratory and the Lawrence Berkeley National Laboratory have discovered a new source of atmospheric organic particulate that has not yet been accounted for in climate models: tiny soil particles that become airborne after a rain event. This new study quantified the effect of raindrop impaction on the generation of these atmospheric particles using experimental irrigation in the Southern Great Plains, OK. The scientists found that, after rainfall, microscopic organic particles from the soil were ejected into the air and contributed up to 60% of atmospheric particles. After studying the physical and chemical properties of these solid particles, the scientists suggested that they could play a critical role in the formation of clouds and subsequent radiative forcing. The authors emphasize the importance of including this source of airborne particle in climate models, particularly for agricultural and grassland ecosystems.

Catastrophic fires may ebb with added moisture

According to the National Interagency Fire Center’s latest Wildland Fire Outlook report, wet weather from El Niño may cause drop in the number of wildfires experienced in the U.S. compared to the record-breaking fire season in 2015. The mountainous West has had large amounts of snowpack, potentially delaying the start of the fire season, particularly in higher-elevation forested areas. Overall, this is a positive outcome of El Niño, however the Outlook projected the Pacific Northwest to have “normal significant wildland fire potential” due to the warmer-than-average weather experienced in the month of April that led to a drop in snowpack.

Coastal/Marine Ecosystems, Ocean Acidification, Sea Level Rise

Juvenile starfish rebound in pockets of the Pacific

Seastar populations along the coast of western North America experienced a drastic two-year decline due to an epidemic wasting disease. However, according to an article by the Associated Press, Oregon State University’s marine biologist Bruce Menge and his colleagues have recorded a massive rebound of larval seastars since 2015. The cause of the epidemic and this sudden boom in seastar population remains largely unknown.

Ocean's oxygen running low

Long, M. C., C. Deutsch, and T. Ito (2016), Finding forced trends in oceanic oxygen, Global Biogeochem. Cycles,30, 381–397, doi:10.1002/2015GB005310.

Unviersity of Washington oceanographer Curtis Deutsch and colleagues have recently published a new study examining the distinction between naturally varying and climate-induced declines in dissolved oxygen levels of the world’s oceans. Using a large ensemble of a single Earth System model, the authors developed a global map of changing oxygen levels and found that it was possible to discern climate-driven changes from other sources. They found that for each degree of warming, oxygen concentration declined by 2 percent. Warmer waters lead to a more stratified ocean which consequently cuts off oxygen supply to habitable parts of the marine ecosystem. Furthermore, increased ocean temperatures cause the metabolic rate of marine species to increase, thus requiring increased oxygen consumption. As Curtis Deutsch stated, this means climate change is squeezing marine species on both sides. That authors stress the importance of including research on dissolved oxygen when discussing the effects of climate change on the ocean. Along with warming and acidification, a decline in oxygen will have extreme impacts on the marine ecosystem.


Are insect outbreaks helping reduce forest fires?

Meigs, G.W., Zald, H.S.J., Campbell, J.L., Keeton, W.S., Kennedy R.E. 2016. Do insect outbreaks reduce the severity of subsequent forest fires? Environmental Research Letters: 11, 4.

Researchers from the University of Vermont and Oregon State University examined the interaction between insect outbreaks and fire severity. Published in Environmental Research Letters, the authors used spatial models and statistical analyses to map 81 fires as well as insect outbreaks over a 25-year period in Oregon and Washington state. Specifically, the study looked at mountain pine beetle and western spruce budworm outbreaks. Findings from this study suggest that the presence of both insects generally reduced wildfire severity by decreasing the abundance of live vegetation susceptible to wildfire at multiple time lags. Because this is contrary to common assumption, the authors recommended a precautionary approach to forest management policies.

Recent advances and remaining uncertainties in resolving past and future climate effects on global fire activity

Williams, A.P., Abatzoglou, J.T. 2016. Recent Advances and Remaining Uncertainties in Resolving Past and Future Climate Effects on Global Fire Activity. Current Climate Change Reports. DOI: 10.1007/s40641-016-0031-0

Scientists Alton Williams and John Abatzoglou recently published a synthesis report on the current advances and uncertainties surrounding the effects of climate on global fire activity. The authors first discussed recent scientific advances toward the discovery of a positive relationship between fire activity and aridity, noting an observed increase in both over the past several decades and the subsequent consequences anthropogenic effects may have on global fire regimes and the terrestrial biosphere. The authors then examined the various models used to study future fire responses to climate change. They described the specific uses for macro-scale models, correlation-based models, and process-based models. The synthesis also emphasized the observation-based research that must continue in order to evaluate interactions between fire, vegetation, climate, and humans.


Study deems 'sudden oak death' unstoppable

Cunniffea, N.J., Cobb, R.C., Meentemeyer, R.K., Rizz, D.M., Gilligan, C.A. 2016. Modeling when, where, and how to manage a forest epidemic, motivated by sudden oak death in California. Proceedings of the National Academy of Sciences.  5640–5645, doi: 10.1073/pnas.1602153113

A type of water mold canonically known as “sudden oak death” is a pathogen that attacks over 100 different species of trees and shrubs by cracking them open and drying them out. This disease, which has been spreading throughout coastal California since 1995, causes forests to become more susceptible to wildfire and lose their role as carbon storages. In a recently published study, scientist Nik Cunniffe and colleagues used a mathematical model to examine the spread of the disease over time. They discovered that, since 2002, the disease has become too widespread and exhibited too fast of a spreading rate to plausibly stop the epidemic. Sudden oak death has also been observed in parts of Oregon, demonstrating the large jumps that the pathogen can take. The models developed through this study were used to recommend control strategies for managing the disease. The authors found that cutting down trees at the “wave-front,” where the disease will subsequently spread, is more effective than cutting down trees at the core of infection.

Scientists create new model to map warming-related threats

Liénard, J., Harrison, J. and Strigul, N. (2016), US forest response to projected climate-related stress: a tolerance perspective. Global Change Biology. doi:10.1111/gcb.13291.

Scientists from Washington State University recently published a study on how U.S. forests will respond to climate change. The authors developed a new quantitative tool, called a Tolerance Distribution Model, that allows for the assessment of landscape-level impacts of climate change. Using this model, the scientists were able to project how forests will change in composition and range across North America. Included in their findings was a projection of the Pacific Northwest; as this region continues to get warmer and wetter, it may become more conducive for forests species currently growing in south-eastern China, southern Brazil, or sub-saharan Africa.

Land Use

USDA guidelines for climate smart agriculture and forestry

The U.S. Department of Agriculture recently released a progress report on their national plan to implement climate smart agriculture and forestry. This plan is to help farmers, ranchers, forestland owners, and rural communities adapt to the impacts of climate change. Detailed in the report are 10 “Building Blocks” that compose the multi-faceted plan with the ultimate goal of reducing greenhouse gas (GHG) emissions, increase carbon sequestration, and generate clean energy and renewable energy. These building blocks include: soil health, nitrogen stewardship, livestock partnerships, conservation of sensitive lands, grazing and pasture lands, private forest growth and retention, stewardship of federal forests, promotion of wood products, urban forests, and energy generation and efficiency. Through the implementation of this plan, the USDA hopes to reduce GHG emissions and increase carbon storage by more than 120 metric tons of carbon dioxide equivalent per year by 2025. Follow the link below to read the full report.

Taking Action

Judge rejects federal recovery plan for Columbia Basin

U.S. District Court Judge Michael Simon has rejected the federal government’s plan to recover steelhead and salmon in the Columbia Basin for the fourth time, claiming that the plan does not make enough effort to protect the fish against the effects of climate change and hydropower dams. With warmer waters, reservoirs behind dams such as those on the Lower Snake River are not conducive to fish survival. Such reservoirs exhibited massive salmon die-offs during the summer of 2015. Judge Simon has given the National Oceanic and Atmospheric Administration two years to rewrite their plan.

Issues with guidance for climate change adaptation plans at a local level

Woodruff, S.C., Stults, M. 2016. Numerous strategies but limited implementation guidance in US local adaptation plans. Nature Climate Change, Doi: 10.1038/nclimate3012

In this new study, scientists from the University of North Carolina and University of Michigan examined 44 climate-adaptation plans being implemented in local communities around the U.S. Using a multivariate regression model, the authors were able to research how the quality of plans varied across communities. The study found that all plans used multiple sources for compiling data and analyzing future impacts, however most failed to develop a detailed action plan with defined priorities. Higher quality plans were associated with the engagement of elected officials and those authored by planning departments, giving insight into how to improve upon local climate-adaptation plans.

Tribal and Indigenous Peoples Matters

Army Corps denies coal terminal permit at Cherry Point

On May 9th, the U.S. Army Corps of Engineers announced its decision to deny the construction of North America’s largest coal export terminal, called the Gateway Pacific Terminal, off of Cherry Point, WA. The waters off of Cherry Point are treaty-protected Lummi Nation fishing waters, and the Seattle District Commander Col. John Buck determined that the construction of the terminal has the potential to impact their rights. Basing their decision off of the district’s statement, the Army Corps denied a permit for the project.