NW Climate Science Digest

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

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: http://dx.doi.org/10.1111/gcb.12879

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.

Coastal Cutthroat Trout Ecohydrology and Habitat use in Irely Creek, Washington

Coastal cutthroat trout are native in the Irely Creek watershed of the upper Quinault River drainage, which is protected as Olympic National Park. This species coexists with anadromous coho salmon, two resident fishes, and several amphibian species. During 2001-2002, cutthroat redds and fry were abundant in the main stem, such that researchers had adequate data to formulate microhabitat suitability curves for spawners and assess the incubation period before fry emergence. The results were similar to spawning resident trout species. Those results suggest that cutthroat trout require lower stream flows than salmon or steelhead for reproduction.

Population Fluctuations of Coastal Cutthroat Trout in Irely Creek, Washington

In the Irely Creek watershed (upper Quinault River drainage) within Olympic National Park, coastal cutthroat coexists with anadromous coho salmon and two resident-fish and several amphibian species. During 2001-2002, cutthroat redds and fry were abundant in the mainstem, particularly in its middle segment, with escapement estimates being 48-106. More recently, the population has declined by an order of magnitude, reflecting summer/fall droughts that have often dried up adult habitat in Irely Lake. Although redd counts have risen when summer/fall seasons have been wetter during 2003-2010, they haven’t reached 2001-2002 counts via regular lake dry-outs, including two consecutive dry-outs during 2002-2003. Hence, the population is showing an overall downward trend with some smaller-scale oscillations coupled with escapement estimates during 2003-2010 ranging from 4 to 32.

Arid Ecosystems

Climate Change and Land Management in the Rangelands of Central Oregon

Creutzburg, M.K., Halofsky, J.E., Halofsky, J.S., Christopher, T.A. 2015. Climate change and land management in the rangelands of central Oregon. Environmental Management, 55(1), 43-55. doi: http://dx.doi.org/ 10.1007/s00267-014-0362-3

Climate change, along with exotic species, disturbances, and land use change, will likely have major impacts on sagebrush steppe ecosystems in the western U.S. over the next century. To effectively manage sagebrush steppe landscapes for long-term goals, managers need information about the interacting impacts of climate change, disturbances and land management on vegetation condition. Using a climate-informed state-and-transition model, researchers evaluated the potential impacts of climate change on rangeland condition in central Oregon and the effectiveness of multiple management strategies. Under three scenarios of climate change, researchers projected shifts in potential vegetation types over the 21st century, with declining sagebrush steppe and expanding salt desert shrub likely by the end of the century. Overall, climate-related shifts dominated future vegetation patterns, making management for improved rangeland condition more difficult. This approach allows researchers and managers to examine long-term trends and uncertainty in rangeland vegetation condition and test the effectiveness of alternative management actions under projected climate change.

Biodiversity/Species and Ecosystem Response

Bull Trout and Climate Vulnerability

USGS aquatic ecologist, Jason Dunham, recently completed the final report on a Northwest Climate Science Center- funded study to determine how climate-related threats will influence bull trout across their southern range in Oregon, Washington, Idaho, Montana, and Nevada. Dunham and his collaborators used stream temperatures predictions to map coldwater “patches” suitable for bull trout spawning and early rearing. Larger patches of cold water with extremely cold - below 10 degrees Celsius - temperatures in summer, fewer floods in winter, and low human influence were much more likely to support the species. This work identified dozens of places where bull trout may exist, but have not yet been detected, as well as other places where bull trout may be at high risk of local extinction. Future work will focus on completing analyses across the remainder of the species’ range.

Influences of Climate Forcing on Freshwater and Forest Biota in the PNW

Black, B. A., Dunham, J. B., Blundon, B. W., Brim-Box, J. and Tepley, A. J. (2015), Long-term growth-increment chronologies reveal diverse influences of climate forcing on freshwater and forest biota in the Pacific Northwest. Global Change Biology, 21: 594–604. doi: http://dx.doi.org/10.1111/gcb.12756

Analyses of how organisms are likely to respond to a changing climate have focused largely on the direct effects of warming temperatures, though changes in other variables may also be important, particularly the amount and timing of precipitation. Researchers developed a network of 8 growth-increment width chronologies for freshwater mussel species in the PNW, and integrated them with tree-ring data to evaluate how terrestrial and aquatic indicators respond to hydroclimatic variability, including river discharge and precipitation. Annual discharge averaged across water years was highly synchronous among river systems and imparted a coherent pattern among mussel chronologies. The leading principal component of the five longest mussel chronologies accounted for 47% of the dataset variability and negatively correlated with the leading principal component of river discharge. Mussel growth was also indirectly related to tree radial growth. Overall, this diverse assemblage of chronologies illustrates the importance of winter precipitation to terrestrial and freshwater ecosystems and suggests that a complexity of climate responses must be considered when estimating the biological impacts of climate variability and change.

Climate and Weather Reports and Services

Projected Changes in Snowfall Extremes and Interannual Variability of Snowfall in the Western US

Lute, A. C., J. T. Abatzoglou, and K. C. Hegewisch (2015), Projected changes in snowfall extremes and interannual variability of snowfall in the western United States, Water Resour. Res., 51, 960–972, doi:10.1002/2014WR016267.

Projected warming will have significant impacts on snowfall accumulation and melt, with implications for water availability and management in snow-dominated regions. Changes in snowfall extremes are confounded by projected increases in precipitation extremes. Downscaled climate projections from 20 global climate models were bias-corrected to montane Snowpack Telemetry stations across the western US to assess mid-21st century changes in the mean and variability of annual snowfall water equivalent (SFE) and extreme snowfall events. Declines in annual SFE and number of snowfall days were projected for all stations. At climatologically cooler locations, such as in the Rocky Mountains, changes in the magnitude of snowfall events mirrored changes in the distribution of precipitation events, with increases in extremes and less change in warmer locations. Common to both warmer and colder sites was a relative increase in the magnitude of snowfall extremes compared to annual SFE and a larger fraction of annual SFE from snowfall extremes.

Climate Science: The Future of Coastal Ocean Upwelling

Many climate models predict that coastal upwelling will intensify in three of the most productive marine ecosystems of the world. This result comes at a time when scientists are still debating the evidence supporting an increase in coastal upwelling and its effects on coastal ecosystems and global carbon cycling. Increased upwelling currents will strongly affect marine ecosystems at Eastern Boundary Upwelling Systems, but the long-term future of coastal acidification, dead zones, and primary productivity probably depends on the properties of the water that comes to the surface.

Interactive Climate Map: Temperature, Precipitation, and Drought Outlooks

The National Oceanic and Atmospheric Administration (NOAA) along with its academic and international partners are making great strides in linking severe weather, winter storms, droughts and floods, and hurricane events to climate variability such as El Niño and La Niña, and other modes of natural climate variability. The Climate Prediction Center (CPC), working with national and international partners, is at the forefront of turning this new understanding into practical tools and useful products for predicting such events and their impacts months to seasons in advance to reduce vulnerability and exploit opportunities for beneficial impacts. Better predictions of extreme climate episodes like floods and droughts could save the United States billions of dollars in damage costs. Water, energy and transportation managers would be able to plan and avoid or mitigate these losses. 

What a Record-Low Snowpack Means for Summer in the Northwest

Scott Pattee, a water supply specialist with the Natural Resources Conservation Service, has been monitoring snow levels in Washington for more than 20 years. The data he gathers helps scientist study climate trends, farmers plan their growing seasons, hydropower operators manage their reservoirs and municipalities provide water to citizens. This year is on track to be one of the lowest snow years on record. Across Washington state, average snowpack is 71 percent below normal levels. In some places, including the Olympic Peninsula, snowpack is 90 percent below normal levels. Things are looking even worse in Oregon. Statewide, average snowpack is 76 percent below normal levels. “One of our longest-monitored sites, near Bend, has the lowest snowpack ever recorded, breaking the 1977 record,” said Julie Koeberle, a hydrologist in Oregon with the Natural Resources Conservation Service. The Bend site has been monitored since the early 1950s.“All eyes will be pointing on southern and southeastern Oregon if things don’t improve,” Koeberle said. Some of the lowest snow levels can be found in those areas, where water scarcity has created drought conditions in recent years.

Detection and Attribution of Climate Change Signal in Ocean Wind Waves

Mikhail Dobrynin, Jens Murawski, Johanna Baehr, and Tatiana Ilyina. 2015. Detection and Attribution of Climate Change Signal in Ocean Wind Waves. Journal of Climate, 28, 1578–1591. doi: http://dx.doi.org/10.1175/JCLI-D-13-00664.1

Researchers recently published a study in the Journal of Climate, which analyzed how surface waves in the ocean respond to variability and changes of climate. Observations and modeling studies indicate trends in wave height over the past decades. Nevertheless, it is currently impossible to discern whether these trends are the result of climate variability or change. The output of an Earth system model (EC-EARTH) produced within phase 5 of the Coupled Model Intercomparison Project (CMIP5) is used here to force a global Wave Model (WAM) in order to study the response of waves to different climate regimes. Detectable climate change signals were found in the current decade (2010–20) in the North Atlantic, equatorial Pacific, and Southern Ocean. Until the year 2060, climate change signals are detectable in 60% of the global ocean area. The authors show that climate change acts to generate detectable trends in wind speed and significant wave height that exceed the positive and the negative ranges of natural variability in different regions of the ocean. Moreover, in more than 3% of the ocean area, the climate change signal is reversible such that trends exceeded both positive and negative limits of natural variability at different points in time. These changes are attributed to local (due to local wind) and remote (due to swell) factors.

Near-term Acceleration in the Rate of Temperature Change

Smith, S.J., Edmonds, J., Hartin, C.A., Mundra, A., Calvin, K. 2015. Near-term acceleration in the rate of temperature change. Nature Climate Change, doi: http://dx.doi.org/10.1038/nclimate2552.

Anthropogenically driven climate changes, which are expected to impact human and natural systems, are often expressed in terms of global-mean temperature. The rate of climate change over multi-decadal scales is also important, with faster rates of change resulting in less time for human and natural systems to adapt. We find that present trends in greenhouse-gas and aerosol emissions are now moving the Earth system into a regime in terms of multi-decadal rates of change that are unprecedented for at least the past 1,000 years. The rate of global-mean temperature increase in the CMIP5 archive over 40-year periods increases to 0.25 ± 0.05 °C per decade by 2020, an average greater than peak rates of change during the previous one to two millennia. Regional rates of change in Europe, North America and the Arctic are higher than the global average. Research on the impacts of such near-term rates of change is urgently needed.

Artificial Amplification of Warming Trends Across Western Mountains

Oyler, J. W., S. Z. Dobrowski, A. P. Ballantyne, A. E. Klene, and S. W. Running (2015). Artificial amplification of warming trends across the mountains of the western United States, Geophysical Research Letters, 42, 153–161, doi: http://dx.doi.org/10.1002/2014GL062803.

Observations from the main mountain climate station network in the western U.S. suggest that higher elevations are warming faster than lower elevations. This has led to the assumption that elevation-dependent warming is prevalent throughout the region with impacts to water resources and ecosystem services. Researchers from the University of Montana critically evaluated this network's temperature observations and show that extreme warming observed at higher elevations is the result of systematic artifacts and not climatic conditions. With artifacts removed, the network's 1991–2012 minimum temperature trend decreases from +1.16°C decade−1 to +0.106°C decade−1 and is statistically indistinguishable from lower elevation trends. In the context of a warming climate, this artificial amplification of mountain climate trends has likely compromised our ability to accurately attribute climate change impacts across the mountainous western U.S.

The West Coast is in Hot Water

The warm water in the eastern Pacific over the past two years is a harbinger of things to come for the region. Ocean temperatures have been rising around the world and are expected to keep warming, and the eastern Pacific could see the odd conditions of the past two years become commonplace by mid-century. Just how far-reaching the impacts will be and which species will adapt and which will fail to is something scientists are still trying to untangle. The causes for the current eastern Pacific warm temperatures — what Washington state climatologist Nick Bond has coined "the blob" — are not fully known, but are most likely natural. The blob has spread across an expanse of water 1,000 miles across with above-normal water temperatures running from the surface to as deep as 300 feet. While human-induced warming is heating seas around the world, Bond said that’s not the main cause for this particular hot spot. “It’s mostly a fluke of climate variability,” Bond said. “At least part of it can be linked to deep convection in the far western tropical Pacific.” 

Coastal/Marine Ecosystems, Ocean Acidification, Sea Level Rise

Naturally Acidic Water of Puget Sound Surround UW’s Friday Harbor Labs

Murray, J. W., Roberts, E., Howard, E., O'Donnell, M., Bantam, C., Carrington, E., Foy, M., Paul, B. and Fay, A. (2015), An inland sea high nitrate-low chlorophyll (HNLC) region with naturally high pCO2. Limnology and Oceanography. doi: http://dx.doi.org/ 10.1002/lno.10062

A paper published last month in Limnology and Oceanography tracks about two years of weekly pH data in Puget Sound, collected since the UW established a facility there to study the effects of ocean acidification. Researchers found typical values of dissolved carbon dioxide, or CO2, in Puget Sound are more than 650 parts per million, higher than even the 400 parts per million threshold that Earth’s atmosphere crossed last year for the first time in modern humans’ existence. In other words, Puget Sound’s water is already higher in the gas than our CO2-choked atmosphere. 

Warming Oceans Storing Up Long Term Climate Impacts, says WMO

Rising ocean temperatures are likely to have “major implications” for the development of climate change, the World Meteorological Organization said. The majority of warming linked to soaring levels of greenhouse gas emissions was being stored in the upper and lower levels of the seas, it said in its annual Status of the Global Climate report for 2014. Sea-surface temperatures were “much warmer than average” across the north Pacific, southwest Pacific, Indian Ocean as well as the polar region of the North Atlantic. Last year was the hottest on record, with global average temperatures 0.57 °C above the 1961-1990 average of 14 °C. 

On Thin Ice: Combined Arctic Ice Observations Show Decades of Loss

Lindsay, R., & Schweiger, A. 2015. Arctic sea ice thickness loss determined using subsurface, aircraft, and satellite observations. The Cryosphere, doi: http://dx.doi.org/ 10.5194/tc-9-269-2015

University of Washington researchers compiled modern and historic measurements to get a full picture of how Arctic sea ice thickness has changed. The results, published in The Cryosphere, show a thinning in the central Arctic Ocean of 65 percent between 1975 and 2012. September ice thickness, when the ice cover is at a minimum, is 85% thinner for the same 37-year stretch. “The ice is thinning dramatically,” said lead author Ron Lindsay, a climatologist at the UW Applied Physics Laboratory. “We knew the ice was thinning, but we now have additional confirmation on how fast, and we can see that it’s not slowing down.” The study helps gauge how much the climate has changed in recent decades, and helps better predict an Arctic Ocean that may soon be ice-free for parts of the year. 


Accelerate Glacier Melt on Mt. Olympus due to Carbon and Dust from Wildfire

Kaspari, S., Skiles, S.M., Delaney, I., Dixon, D., Painter, T.H. 2015. Accelerated glacier melt on snow dome, Mt. Olympus, Washington, USA due to deposition of black carbon and mineral dust from wildfire. Journal of Geophysical Research, doi: http://dx.doi.org/10.1002/2014JD022676

Assessing the potential for black carbon and dust deposition to reduce albedo and accelerate glacier melt is of interest in Washington because snow and glacier melt are an important source of water resources, and glaciers are retreating. In August 2012 on Snow Dome Mt Olympus, Washington, researchers measured snow surface spectral albedo and collected surface snow samples and a 7 m ice core. The samples were microscopically analyzed for iron, black carbon, and charcoal. Results show that black carbon and dust deposition was a magnitude higher in 2011 than 2012, and identified the 2011 Big Hump forest fire on the Olympic Peninsula as the source of the greatly elevated impurity deposition. The forest fire impurity reduced albedo, increased the radiative forcing, and enhanced snowmelt. 

Lack of Snowpack Could Mean Early Central Oregon Fire Season

 A warm winter with light snowfall in the mountains near Bend means wildfire season could come early. Timber fires do not typically occur in Central Oregon until August, said Ed Keith, Deschutes County forester, but the lack of snow may lead to big blazes earlier. “This year it may be June or July,” he said. The Deschutes/Crooked River Basin snowpack was only 9 percent of normal for this time of year, according to the Natural Resources Conservation Service. Many of the automated snow sites monitored by the federal agency report no snow for the first time in three decades of recording data. A year ago the basin had 54 percent of the normal snowpack on March 20. “We are gaining some precipitation now, which will help,” said Rachel Cobb, a Weather Service meteorologist in Pendleton, “but I don’t know if it will be enough to make up for what we didn’t get over the winter.” 


Scientists Warn Climate Change is Threatening World's Most Expansive Temperate Rainforests

Climate change poses significant threats to Pacific coastal rainforests of North America. Land managers lack a coordinated climate change adaptation approach with which to prepare the region's globally outstanding biodiversity for accelerating change. Researchers from the Geos Institute provided analyses intended to inform coordinated adaptation for eight focal rainforest tree species of commercial importance and broad rainforest communities. By using two different approaches to determine vulnerability, including climate envelope modeling and the MC1 dynamic vegetation model, researchers were able to assess where Pacific coastal rainforests might be more stable over time. Based on model outputs, focal rainforest conifers and general rainforest communities are more likely to persist and to expand their ranges along northern range margins while southern margins exhibited lower persistence and potential loss of suitable climate. 

New Model to Simulate Climate-Change Impacts on Forest Succession for Local Land Management

Gabriel I. Yospin, Scott D. Bridgham, Ronald P. Neilson, John P. Bolte, Dominique M. Bachelet, Peter J. Gould, Constance A. Harrington, Jane A. Kertis, Cody Evers, and Bart R. Johnson 2015. A new model to simulate climate-change impacts on forest succession for local land management. Ecological Applications 25:226–242. http://dx.doi.org/10.1890/13-0906.1

Researchers developed a new climate-sensitive vegetation state-and-transition simulation model (CV-STSM) to simulate future vegetation at a fine spatial grain commensurate with the scales of human land-use decisions, and under the joint influences of changing climate, site productivity, and disturbance. Researchers conducted experimental simulations in the Willamette Valley, Oregon. The simulation landscape incorporated detailed new assessments of critically imperiled Oregon white oak savanna and prairie habitats among the suite of existing and future vegetation types. The experimental design fully crossed four future climate scenarios with three disturbance scenarios. Results indicate that dynamic global vegetation models may overestimate future rates of vegetation change, especially in the absence of stand-replacing disturbances. Modeling tools such as CV-STSM that simulate rates and direction of vegetation change affected by interactions and feedbacks between climate and land-use change can help policy makers, land managers, and society as a whole develop effective plans to adapt to rapidly changing climate.

Tracking Tree Movement Along the West Coast

Monleon, V. J., & Lintz, H. E. (2015). Evidence of Tree Species’ Range Shifts in a Complex Landscape. PLoS ONE,  doi: http://dx.doi.org/10.1371/journal.pone.0118069

Researchers from the Pacific Northwest Research Station and Oregon State University published a paper titled, “Evidence of tree species' range shifts in a complex landscape.” They compared the distribution of seedlings and mature trees for all but the rarest tree species in California, Oregon and Washington, a large, environmentally diverse region. Across 46 species, the mean annual temperature of the range of seedlings was 0.120°C colder than that of the range of trees. The extremes of the seedling distributions also shifted towards colder temperature than those of mature trees, but the change was less pronounced. Although the mean elevation and mean latitude of the range of seedlings was higher than and north of those of the range of mature trees, elevational and latitudinal shifts run in opposite directions for the majority of the species, reflecting the lack of a direct biological relationship between species’ distributions and those variables. The broad scale, environmental diversity and variety of disturbance regimes and land uses of the study area, the large number and exhaustive sampling of tree species, and the direct causal relationship between the temperature response and a warming climate, provide strong evidence to attribute the observed shifts to climate change.

Special Reports / Announcements

Drought Emergency Declared in Parts of Washington State

Gov. Jay Inslee declared a drought emergency for three regions in Washington state, clearing the way for state officials to provide money and other relief to those experiencing drought hardships. The emergency was prompted by near record-low mountain snowpack, which supplies much of the water in the region when it melts in drier summer months. Officials said the worst drought conditions are in the Olympic Peninsula, the east side of the central Cascade Mountains including Yakima and Wenatchee, and the Walla Walla region. 

Northwest Climate Science Center Announces Climate Boot Camp 2015

The NW CSC is pleased to announce its 2015 Climate Boot Camp, to be held in Pack Forest, WA, Aug. 16-21. This annual retreat is designed to support and train graduate students and early career professionals to work at the interface of scientific research on climate and resource management decision-making. Participants included NW CSC Graduate Fellows, Graduate Fellows from other CSCs, and early career professionals working with northwest Tribes, NGOs, and state and federal resource management agencies. 

Feds Declare Drought Emergency in 13 Oregon Counties, Releasing Aid Money

regon's worsening drought has triggered a federal disaster loan program in 13 Oregon counties. The U.S Small Business Administration announced that low-interest loans meant to offset economic losses associated with the drought are now available for small, non-farm businesses in Grant, Jackson, Baker, Crook, Douglas, Harney, Josephine, Klamath, Malheur, Morrow, Umatilla, Union and Wheeler counties, as well as California's Siskiyou County. 

Northwest Climate Science Center Creates Online Climate Data Resources Library

The Department of the Interior's Northwest Climate Science Center has compiled a selection of web-based resources that deliver datasets, maps, and tools related to climate change and climate change impacts in the northwestern United States. The portal also includes links to species and ecosystem vulnerability assessments and climate adaptation databases. This information is intended to support local, landscape, or regional planning and adaptation efforts. 

Taking Action

Climate Change, Coastal Tribes and Indigenous Communities

Sea level rise, associated with climate change, is threatening natural resources, communities and cultures across the United States, its territories and freely associated states. Climate change will impact many indigenous communities and may well endanger sacred and traditional living sites, cultural practices, local forests and ecosystems, traditional foods and water quality. In response, scientists are working with coastal communities throughout the nation to study the impacts of climate change on the health and vitality of the social, economic and natural systems of these communities. Earlier this month, U.S. Secretary of the Interior Sally Jewell announced the Interior Department would make available $8 million to fund projects that promote tribal climate change adaptation and ocean and coastal management planning through its Tribal Climate Resilience Program. To further support coastal tribes and indigenous peoples in addressing challenges of climate change, the Department of the Interior is conducting research at its eight regionally located Climate Science Centers. The mission of the DOI Climate Science Centers is to provide scientific information and tools to policy makers and managers of parks, refuges and other cultural and natural areas, concentrated on helping species, ecosystems and human communities adapt to climate change. 

Tribal and Indigenous Peoples Matters

Swinomish Tribe Studies Effect of Climate Change on Community, Culture

Climate change threatens not only the environment, but also tribal communities whose culture, livelihood and identities depend on natural resources. “Current climate change assessments omit key community health concerns, which are vital to successful adaptation plans, particularly for indigenous communities,” said Jamie Donatuto, environmental health specialist for the Swinomish Tribe. “Recent assessments show that indigenous communities, especially coastal communities, are disproportionately vulnerable to a number of climate impacts as reservation boundaries are fixed and many aspects of their culture are so closely tied to coastal health” said Eric Grossman, coastal and marine geologist with the U.S. Geological Survey (USGS) and partner in the project. Donatuto and Larry Campbell, Swinomish elder and tribal historic preservation officer, developed a set of indigenous indicators to evaluate aspects of community health that other assessments leave out. The indicators prioritize self-determination, community connection, natural resources security, and cultural use and practice.