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Abstract (from http://onlinelibrary.wiley.com/doi/10.1002/2016GB005493/abstract): Phytoplankton growth in the Gulf of Alaska (GoA) is limited by iron (Fe), yet Fe sources are poorly constrained. We examine the temporal and spatial distributions of Fe, and its sources in the GoA, based on data from three cruises carried out in 2010 from the Copper River (AK) mouth to beyond the shelf break. April data are the first to describe late winter Fe behavior before surface water nitrate depletion began. Sediment resuspension during winter and spring storms generated high “total dissolvable Fe” (TDFe) concentrations of ~1000 nmol kg−1 along the entire continental shelf, which decreased beyond the shelf break. In July, high...
Abstract (from http://onlinelibrary.wiley.com/doi/10.1002/2014GL060199/abstract): While recent work demonstrates that glacial meltwater provides a substantial and relatively labile flux of the micronutrient iron to oceans, the role of high-latitude estuary environments as a potential sink of glacial iron is unknown. Here we present the first quantitative description of iron removal in a meltwater-dominated estuary. We find that 85% of “dissolved” Fe is removed in the low-salinity region of the estuary along with 41% of “total dissolvable” iron associated with glacial flour. We couple these findings with hydrologic and geochemical data from Gulf of Alaska (GoA) glacierized catchments to calculate meltwater-derived...
This data release is provided in support of Arismendi, I., Dunham, J.B., Heck, M.P., Schultz, L.D., Hockman-Wert, D.P., 2017, A statistical method to predict flow permanence in dryland streams from time series of stream temperature: Water, v. 9, no. 12, p. 946, https://doi.org/10.3390/w9120946. This code release contains all of the source code from the "Hidden Markov Model" sections of the associated manuscript. The source code was written using the R programming language (www.r-project.org, version 3.3.1). Running the code requires knowlege of the R programming language. The code snippet requires the folder location containing the data, and the site being processed, to be updated. The code requires certain R packages,...
Efforts to conserve stream and river biota could benefit from tools that allow managers to evaluate landscape-scale changes in species distributions in response to water management decisions. We present a framework and methods for integrating hydrology, geographic context and metapopulation processes to simulate effects of changes in streamflow on fish occupancy dynamics across a landscape of interconnected stream segments. We illustrate this approach using a 482 km2 catchment in the southeastern US supporting 50 or more stream fish species. A spatially distributed, deterministic and physically based hydrologic model is used to simulate daily streamflow for sub-basins composing the catchment. We use geographic data...
Abstract (from http://onlinelibrary.wiley.com/doi/10.1111/1752-1688.12304/abstract): The hydrologic response to statistically downscaled general circulation model simulations of daily surface climate and land cover through 2099 was assessed for the Apalachicola-Chattahoochee-Flint River Basin located in the southeastern United States. Projections of climate, urbanization, vegetation, and surface-depression storage capacity were used as inputs to the Precipitation-Runoff Modeling System to simulate projected impacts on hydrologic response. Surface runoff substantially increased when land cover change was applied. However, once the surface depression storage was added to mitigate the land cover change and increases...
Abstract: A significant number of historically existing wetlands that naturally stored rainwater and attenuated flood peaks have now been drained and employed as new farming areas. Beyond the water quality and flow problem, this has resulted in loss of natural habitats of diverse ecological species. Restoring wetlands have hence been proposed as a potential conservation strategy to help attenuate many of these problems. In this study a spatial, multi-objective optimization study of new potential wetlands was carried out to achieve biodiversity improvements in addition to flood reduction benefits and water quality improvements. The Soil and Water Assessment Tool (SWAT) was used to simulate flow and water quality,...
Abstract (from PNAS): Recent decades have seen droughts across multiple US river basins that are unprecedented over the last century and potentially longer. Understanding the drivers of drought in a long-term context requires extending instrumental data with paleoclimatic data. Here, a network of new millennial-length streamflow reconstructions and a regional temperature reconstruction from tree rings place 20th and early 21st century drought severity in the Upper Missouri River basin into a long-term context. Across the headwaters of the United States’ largest river basin, we estimated region-wide, decadal-scale drought severity during the “turn-of-the-century drought” ca. 2000 to 2010 was potentially unprecedented...
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Changes in stream temperature can have significant impacts on water quality and the health and survival of aquatic fish and wildlife. Water managers, planners, and decision makers are in need of scientific data to help them prepare for and adapt to changes and conserve important resources. Scientists are tasked with ensuring that this data is produced in useful formats and is accessible to these stakeholders. In October 2015, project researchers hosted and facilitated a 1.5 day workshop, “Data Storage, Dissemination and Harvesting”, that brought together over 50 stakeholders from state and federal agencies, tribal governments, universities, and non-profit organizations interested in monitoring stream temperature...
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The Jago, Okpilak, and Hulahula rivers in the Arctic are heavily glaciated waterways that are important for fish and wildlife as well as human activities including the provision of food, recreation, and, potentially, resource extraction on the coastal plain. If current glacial melting trends continue, most of the ice in these rivers will disappear in the next 50-100 years. Because of their importance to human and natural communities, it is critical to understand how these rivers and their surrounding environments will be affected by climate change and glacier loss. The overarching goal of this project was to research (1) the amount of river water, sediment, nutrients, and organic matter in the Jago, Okpilak, and...
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Elodea spp. (Elodea) is Alaska’s first known invasive aquatic plant, first discovered in urban lakes in 2010. The combination of human pathways and climate change related shifts in seasonality and temperature have resulted in Elodea’s range expansion into Alaska’s freshwater resources. Elodea transmission often occurs when plant fragments get entangled in seaplane rudders and are carried to remote waterbodies where they quickly establish dense plant growth. This growth inhibits seaplane access and drastically alters aquatic ecosystems. Recent research showed that Elodea can have significant negative impacts on parks, subsistence, aviation‐related recreation, and Alaska’s salmon fisheries. For example, the economic...
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Future climate conditions in the Upper Mississippi River Basin are projected to include many more extreme precipitation events. These intense periods of rain can lead to flooding of the Mississippi River itself, as well the small streams and rivers that feed it. This flooding presents a challenge for local communities, farmers, small businesses, river users, and the ecosystems and wildlife in the area. To reduce the damage done by these extreme rainfall events, ‘natural solutions’ are often helpful. This might include preserving forests and grasslands to absorb rainwater before it arrives at streams or restoring wetlands to slow and clean runoff water. For river and natural resource managers to adapt to future climate...
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The Midwest has experienced some of the costliest flooding events in U.S. history, including many billions of dollars during the past decade alone. The Midwest’s susceptibility to flooding has been exacerbated by a long-term increase in total precipitation and extreme rainfalls, with the 2010s being the region’s wettest decade on record Climate models strongly indicate that these recent trends will continue, such that the warming Midwest will experience wetter winters and springs, shortened snow seasons, and extreme year-round precipitation in the future. Despite this high level of confidence in climate trends, there is limited knowledge of how these will translate to flood likelihood and the associated societal...
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Streamflow in the Colorado River is heavily influenced by high-elevation snowpack. Warming temperatures in spring can reduce snow-fed flows, with serious implications for the water supplies that support communities and wildlife. While it is already well-known that precipitation has a significant influence on river flow, recent observations suggest that temperature and the amount of water in soil may also influence streamflow. In the face of a changing climate, it is important that resource managers understand how factors such as changing temperatures and precipitation will affect this vital water source. To address this need, researchers are examining records of streamflow, temperature, soil moisture, and precipitation...
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In the Western U.S., approximately 65% of the water supply comes from forested regions with most of the water that feeds local rivers coming from snowmelt that originates in mountain forests. The Rio Grande headwaters (I.e. the primary water generating region of the Rio Grande river) is experiencing large changes to the landscape primarily from forest fires and bark beetle infestations. Already, 85% of the coniferous forests in this region have been affected by the bark beetle, and projections indicate greater changes will occur as temperatures increase. In this area, most of the precipitation falls as snow in the winter, reaches a maximum depth in the late spring, and melts away due to warmer temperatures by early...
This code computes the analytical solution for the damping of sinusoidal infiltration in variably saturated soils described by Bakker and Neiber (2009) and implemented by Dickinson et al. (2014). The usage of the code is documented in the appendix of Dickinson et al. (2014). Bakker, M., Nieber, J.L., 2009. Damping of sinusoidal surface flux fluctuations with soil depth. Vadose Zone J. 8, 119–126,http://dx.doi.org/10.2136/vzj2008.0084. Dickinson, J.E., Ferré, T.P.A., Bakker, M., Crompton, B., 2014. A screening tool for delineating subregions of steady recharge within groundwater models.Vadose Zone J. 13, 15, http://dx.doi.org/10.2136/vzj2013.10.0184. The code can be obtained at http://az.water.usgs.gov/software/damp.html
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Mean modeled snow-water-equivalent (meters) on February 20, the date of peak basin-integrated mean modeled snow-water-equivalent (meters) for the T4 climate change scenario. Reference period: the period 1989 – 2011 for the Upper Deschutes River Basin domain, for which observed historical meteorology is used for model input. T4 scenario: the observed historical (reference period) meteorology is perturbed by adding +4°C to each daily temperature record in the reference period meteorology, and this data is then used as input to the model.
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The percentage difference between mean modeled snow-water-equivalent (meters) on April 1 for the reference (1989-2011) climate period and mean modeled snow-water-equivalent on April 1 for the T4 climate change scenario. Reference period: the period 1989 – 2011 for the Upper Deschutes River Basin domain, for which observed historical meteorology is used for model input. T4 scenario: the observed historical (reference period) meteorology is perturbed by adding +4°C to each daily temperature record in the reference period meteorology, and this data is then used as input to the model.
map background search result map search result map The Impacts of Glacier Change on the Jago, Okpilak, and Hulahula Rivers in the Arctic Examining the Influence of Temperature and Precipitation on Colorado River Water Resources: Reconstructing the Past to Understand the Future Modeled snow-water-equivalent, percent difference between historical and projected April 1 values under T4 climate change scenario, Upper Deschutes River Basin, Oregon [full and clipped versions] Modeled snow-water-equivalent, projected seasonal peak values under T4 climate change scenario, Upper Deschutes River Basin, Oregon [full and clipped versions] Prioritizing Stream Temperature Data Collection to Meet Stakeholder Needs and Inform Regional Analyses Estimating the Future Effects of Forest Disturbance on Snow Water Resources in a Changing Environment Detecting and Predicting Aquatic Invasive Species Transmission Via Seaplanes in Alaska Workshop: Natural Solutions to Ecological and Economic Problems Caused by Extreme Precipitation Events in the Upper Mississippi River Basin The Combined Effects of Seasonal Climate and Extreme Precipitation on Flood Hazard in the Midwest Modeled snow-water-equivalent, percent difference between historical and projected April 1 values under T4 climate change scenario, Upper Deschutes River Basin, Oregon [full and clipped versions] Modeled snow-water-equivalent, projected seasonal peak values under T4 climate change scenario, Upper Deschutes River Basin, Oregon [full and clipped versions] Estimating the Future Effects of Forest Disturbance on Snow Water Resources in a Changing Environment The Impacts of Glacier Change on the Jago, Okpilak, and Hulahula Rivers in the Arctic Examining the Influence of Temperature and Precipitation on Colorado River Water Resources: Reconstructing the Past to Understand the Future Workshop: Natural Solutions to Ecological and Economic Problems Caused by Extreme Precipitation Events in the Upper Mississippi River Basin The Combined Effects of Seasonal Climate and Extreme Precipitation on Flood Hazard in the Midwest Prioritizing Stream Temperature Data Collection to Meet Stakeholder Needs and Inform Regional Analyses Detecting and Predicting Aquatic Invasive Species Transmission Via Seaplanes in Alaska