Orange streams are increasingly common in the Brooks Range of northern Alaska. The orange stream color reflects oxidized iron, but also often indicates elevated heavy metal concentrations. Our ongoing study aims to document these occurrences and the timing of their onset.
Joshua C Koch, Ph.D.
Surface water / groundwater interactions; hyporheic zone hydrology and biogeochemistry; carbon, nitrogen, and phosphorus cycling; flow above / through frozen ground; preferential flow and soil pipe formation and transport.
Professional Experience
2011 - Present Research Hydrologist, U.S. Geological Survey (USGS), Anchorage, AK
2006 - 2011 Student Hydrologist, Branch of Regional Research, USGS, Boulder, CO
2005 - 2006 Research Assistant, Institute of Alpine and Arctic Research, University of Colorado, Boulder
2003 - 2005 Research Assistant, Semi-Arid Hydrology and Riparian Areas, University of Arizona, Tucson, AZ
2002 - 2003 Hydrologist Intern, Branch of Regional Research, USGS, Lakewood, CO
2001 - 2002 Hydrologist Intern, MA-RI Water District, USGS, Northborough, MA
Education and Certifications
PhD 2010 University of Colorado, Boulder, CO Civil, Environmental, and Architectural Engineering
MS 2005 University of Arizona, Tucson, AZ Department of Hydrology
BA 2001 Wesleyan University, Middletown, CT Earth and Environmental Sciences
Affiliations and Memberships*
American Geophysical Union, Hydrology and Cryosphere Sections
American Water Resources Association - Alaska Chapter
Association of Polar Early Career Scientists
Science and Products
Hydro-Ecology of Arctic Thawing (HEAT): Hydrology
The Rusting of Arctic Rivers: Freshwater Ecosystems Respond to Rapidly Uptaking Metals
Q&A: Arctic Rivers Project
Groundwater Flow and Temperature Modeling to Predict Stream Temperatures in Beaver Creek, Kenai Peninsula, Alaska
Assessment of Critical Landscape Conditions and Potential Change in the Coastal Plain of the Arctic National Wildlife Refuge to Support Habitat Management Decision Making
Beavers Impacting Tundra Ecosystems (BITE)
Biogeochemistry of glaciers
Arctic Lake Food Webs
Hydro-Ecology of Arctic Thawing (HEAT): Ecology
Wolverine Glacier Ecosystem Studies
Matanuska-Susitna Borough Wetland Modeling
Arctic Coastal Plain Studies
Macroinvertebrates from Rivers in Northwest Alaska, 2015-2019
Hydrochemistry and Age Date Tracers from Springs, Streams, and Rivers in the Arctic National Wildlife Refuge, 2019-2022
Chemistry of Orange and Reference Streams in Northwestern Alaska
Length, Weight, Energy Density, and Isotopic Values of Fish from Rivers in Northwest Alaska, 2015-2019
Macroinvertebrates From Streams and Springs in the 1002 Region of the Arctic National Wildlife Refuge, Alaska, 2021
Frequency domain electromagnetic induction (FDEM) geophysical data collected near the Agashashok River in the Noatak National Preserve, AK
Water Level, Temperature, and Discharge in West Twin Creek, Alaska, 2010 to 2012
Stream and River Chemistry in Watersheds of Northwestern Alaska, 2015-2019
Stream Temperatures in the Noatak River and Kobuk River Basins, Northwest Alaska, 2017 - 2019
Wetland Stream Water Quality Data for West Twin Creek, AK, Allequash Creek, WI, and Big Thompson River, CO, 2010-2020
Geochemistry of Water Sources in the Wolverine Glacier Watershed, Alaska in 2016 and 2017
Continuous Records of Shallow Soil Temperature and Moisture in the Noatak River Basin, Alaska
Orange streams are increasingly common in the Brooks Range of northern Alaska. The orange stream color reflects oxidized iron, but also often indicates elevated heavy metal concentrations. Our ongoing study aims to document these occurrences and the timing of their onset.
Orange streams are increasingly common in the Brooks Range of northern Alaska. The orange stream color reflects oxidized iron, but also often indicates elevated heavy metal concentrations. Our ongoing study aims to document these occurrences and the timing of their onset.
Orange streams are increasingly common in the Brooks Range of northern Alaska. The orange stream color reflects oxidized iron, but also often indicates elevated heavy metal concentrations. Our ongoing study aims to document these occurrences and the timing of their onset.
Orange streams are increasingly common in the Brooks Range of northern Alaska. The orange stream color reflects oxidized iron, but also often indicates elevated heavy metal concentrations. Our ongoing study aims to document these occurrences and the timing of their onset.
Orange streams are increasingly common in the Brooks Range of northern Alaska. The orange stream color reflects oxidized iron, but also often indicates elevated heavy metal concentrations. Our ongoing study aims to document these occurrences and the timing of their onset.
Orange streams are increasingly common in the Brooks Range of northern Alaska. The orange stream color reflects oxidized iron, but also often indicates elevated heavy metal concentrations. Our ongoing study aims to document these occurrences and the timing of their onset.
Orange streams are increasingly common in the Brooks Range of northern Alaska. The orange stream color reflects oxidized iron, but also often indicates elevated heavy metal concentrations. Our ongoing study aims to document these occurrences and the timing of their onset.
Orange streams are increasingly common in the Brooks Range of northern Alaska. The orange stream color reflects oxidized iron, but also often indicates elevated heavy metal concentrations. Our ongoing study aims to document these occurrences and the timing of their onset.
Orange streams are increasingly common in the Brooks Range of northern Alaska. The orange stream color reflects oxidized iron, but also often indicates elevated heavy metal concentrations. Our ongoing study aims to document these occurrences and the timing of their onset.
Orange streams are increasingly common in the Brooks Range of northern Alaska. The orange stream color reflects oxidized iron, but also often indicates elevated heavy metal concentrations. Our ongoing study aims to document these occurrences and the timing of their onset.
Orange streams are increasingly common in the Brooks Range of northern Alaska. The orange stream color reflects oxidized iron, but also often indicates elevated heavy metal concentrations. Our ongoing study aims to document these occurrences and the timing of their onset.
Orange streams are increasingly common in the Brooks Range of northern Alaska. The orange stream color reflects oxidized iron, but also often indicates elevated heavy metal concentrations. Our ongoing study aims to document these occurrences and the timing of their onset.
Orange streams are increasingly common in the Brooks Range of northern Alaska. The orange stream color reflects oxidized iron, but also often indicates elevated heavy metal concentrations. Our ongoing study aims to document these occurrences and the timing of their onset.
Orange streams are increasingly common in the Brooks Range of northern Alaska. The orange stream color reflects oxidized iron, but also often indicates elevated heavy metal concentrations. Our ongoing study aims to document these occurrences and the timing of their onset.
Orange streams are increasingly common in the Brooks Range of northern Alaska. The orange stream color reflects oxidized iron, but also often indicates elevated heavy metal concentrations. Our ongoing study aims to document these occurrences and the timing of their onset.
Orange streams are increasingly common in the Brooks Range of northern Alaska. The orange stream color reflects oxidized iron, but also often indicates elevated heavy metal concentrations. Our ongoing study aims to document these occurrences and the timing of their onset.
Orange streams are increasingly common in the Brooks Range of northern Alaska. The orange stream color reflects oxidized iron, but also often indicates elevated heavy metal concentrations. Our ongoing study aims to document these occurrences and the timing of their onset.
Orange streams are increasingly common in the Brooks Range of northern Alaska. The orange stream color reflects oxidized iron, but also often indicates elevated heavy metal concentrations. Our ongoing study aims to document these occurrences and the timing of their onset.
Orange streams are increasingly common in the Brooks Range of northern Alaska. The orange stream color reflects oxidized iron, but also often indicates elevated heavy metal concentrations. Our ongoing study aims to document these occurrences and the timing of their onset.
Orange streams are increasingly common in the Brooks Range of northern Alaska. The orange stream color reflects oxidized iron, but also often indicates elevated heavy metal concentrations. Our ongoing study aims to document these occurrences and the timing of their onset.
Orange streams are increasingly common in the Brooks Range of northern Alaska. The orange stream color reflects oxidized iron, but also often indicates elevated heavy metal concentrations. Our ongoing study aims to document these occurrences and the timing of their onset.
Orange streams are increasingly common in the Brooks Range of northern Alaska. The orange stream color reflects oxidized iron, but also often indicates elevated heavy metal concentrations. Our ongoing study aims to document these occurrences and the timing of their onset.
Orange streams are increasingly common in the Brooks Range of northern Alaska. The orange stream color reflects oxidized iron, but also often indicates elevated heavy metal concentrations. Our ongoing study aims to document these occurrences and the timing of their onset.
Orange streams are increasingly common in the Brooks Range of northern Alaska. The orange stream color reflects oxidized iron, but also often indicates elevated heavy metal concentrations. Our ongoing study aims to document these occurrences and the timing of their onset.
Orange streams are increasingly common in the Brooks Range of northern Alaska. The orange stream color reflects oxidized iron, but also often indicates elevated heavy metal concentrations. Our ongoing study aims to document these occurrences and the timing of their onset.
The Sadlerochit Spring is one of a handful of small springs that provides liquid water to the North Slope of Alaska year round. Given that most other water sources in this region are frozen in the winter, springs provide critical habitat for fish and macroinvertebrates, and may play an outsized role in the regions hydrologic cycle.
The Sadlerochit Spring is one of a handful of small springs that provides liquid water to the North Slope of Alaska year round. Given that most other water sources in this region are frozen in the winter, springs provide critical habitat for fish and macroinvertebrates, and may play an outsized role in the regions hydrologic cycle.
Ice-rich permafrost exerts a strong control on hydrology in Arctic regions because it limits infiltration, leading to large runoff events.
Ice-rich permafrost exerts a strong control on hydrology in Arctic regions because it limits infiltration, leading to large runoff events.
A gravel bar on the north fork of the Agashashok River, Alaska. This work is part of the Hydro-Ecology of Arctic Thawing (HEAT): Hydrology project that takes place in the Arctic Network Parks because they lie in a region that is rapidly warming.
A gravel bar on the north fork of the Agashashok River, Alaska. This work is part of the Hydro-Ecology of Arctic Thawing (HEAT): Hydrology project that takes place in the Arctic Network Parks because they lie in a region that is rapidly warming.
A misty morning in the headwaters of the Akillik River, Alaska. This work is part of the Hydro-Ecology of Arctic Thawing (HEAT): Hydrology project that takes place in the Arctic Network Parks because they lie in a region that is rapidly warming.
A misty morning in the headwaters of the Akillik River, Alaska. This work is part of the Hydro-Ecology of Arctic Thawing (HEAT): Hydrology project that takes place in the Arctic Network Parks because they lie in a region that is rapidly warming.
A small stream meanders through ice-rich polygonal ground in the Cutler River Basin, Alaska. This work is part of the Hydro-Ecology of Arctic Thawing (HEAT): Hydrology project that takes place in the Arctic Network Parks because they lie in a region that
A small stream meanders through ice-rich polygonal ground in the Cutler River Basin, Alaska. This work is part of the Hydro-Ecology of Arctic Thawing (HEAT): Hydrology project that takes place in the Arctic Network Parks because they lie in a region that
Hiking up a stream from the Akilik River drainage to set minnow traps for fish sampling. This is a stream type at the Boreal-Arctic transition of the Brooks Range, Noatak National Park and Preserve, Kobuk Valley National Park.
Hiking up a stream from the Akilik River drainage to set minnow traps for fish sampling. This is a stream type at the Boreal-Arctic transition of the Brooks Range, Noatak National Park and Preserve, Kobuk Valley National Park.
A flooding stream meanders through a permafrost landscape in Kobuk Valley National Park, Alaska. This work is part of the Hydro-Ecology of Arctic Thawing (HEAT): Hydrology project that takes place in the Arctic Network Parks because they lie in a region
A flooding stream meanders through a permafrost landscape in Kobuk Valley National Park, Alaska. This work is part of the Hydro-Ecology of Arctic Thawing (HEAT): Hydrology project that takes place in the Arctic Network Parks because they lie in a region
The Agashashok River and Asik watershed
The Agashashok River and Asik watershed
A high-resolution, daily hindcast (1990-2021) of Alaskan river discharge and temperature from coupled and optimized physical models
A comparison of contemporary and historical hydrology and water quality in the foothills and coastal plain of the Arctic National Wildlife Refuge, Arctic Slope, northern Alaska
Seasonal and decadal subsurface thaw dynamics of an Aufeis feature investigated through numerical simulations
The Arctic Rivers Project: Using an equitable co-production framework for integrating meaningful community engagement and science to understand climate impacts
Comparing sediment microbial communities of Arctic beaver ponds to tundra lakes and streams
Increasing Alaskan river discharge during the cold season is driven by recent warming
In hot water? Patterns of macroinvertebrate abundance in Arctic thaw ponds and relationships with environmental variables
Evaluating hydrologic region assignment techniques for ungaged basins in Alaska, USA
How beavers are changing Arctic landscapes and Earth’s climate
Sensitivity of headwater streamflow to thawing permafrost and vegetation change in a warming Arctic
Heterogeneous patterns of aged organic carbon export driven by hydrologic flow paths, soil texture, fire, and thaw in discontinuous permafrost headwaters
Multi-year, spatially extensive, watershed-scale synoptic stream chemistry and water quality conditions for six permafrost-underlain Arctic watersheds
Arctic Rivers Project: Connecting Indigenous knowledge and western science to strengthen collective understanding of the changing Arctic
The Arctic Rivers Project will weave together Indigenous knowledges, monitoring, and the modeling of climate, rivers (flows, temperature, ice), and fish to improve understanding of how Arctic rivers, ice transportation corridors, fish, and communities might be impacted by and adapt to climate change.
Science and Products
- Science
Filter Total Items: 17
Hydro-Ecology of Arctic Thawing (HEAT): Hydrology
The Arctic is warming at higher rates than much of the rest of the world. For Alaska, this results in changes in hydrology and ecosystems – permafrost is thawing, changing landscapes and releasing nutrients to soils and streams.The Rusting of Arctic Rivers: Freshwater Ecosystems Respond to Rapidly Uptaking Metals
The water quality of streams and rivers in the Arctic is sensitive to rapid climate change and altered disturbance regimes.Q&A: Arctic Rivers Project
Alaska is home to numerous cultural and linguistic Indigenous groups and the largest number of Federally Recognized Tribes in the United States. Indigenous Alaskans, often living in rural remote communities, are facing multiple impacts due to climate change. As infrastructure, landscapes, and subsistence resources continue to be impacted by warming temperatures, the safety, well-being, and...Groundwater Flow and Temperature Modeling to Predict Stream Temperatures in Beaver Creek, Kenai Peninsula, Alaska
Salmon are an important resource to the ecosystems, economy, and culture of the Kenai Peninsula, Alaska. However, salmon are under increasing stress due to warming water temperatures and decreasing stream flow. Groundwater is a major contributor to many streams that can help maintain fish habitat during low flows and contributes cooler water that regulates stream temperatures in the warm summer moAssessment of Critical Landscape Conditions and Potential Change in the Coastal Plain of the Arctic National Wildlife Refuge to Support Habitat Management Decision Making
Areas along the Arctic coast are changing the fastest among all of Earth’s habitats due to climate change. The Arctic coast is a fragile ecosystem that provides habitat for migratory birds, endangered species, and species critical for local subsistence living. In this area, permafrost is thawing rapidly, changing how much and when water reaches rivers, ponds, lakes, wetlands and groundwater. In adBeavers Impacting Tundra Ecosystems (BITE)
The range expansion of the North American beaver ( Castor canadensis ) has implications for water quality, aquatic ecosystems, and fisheries in Arctic streams.Biogeochemistry of glaciers
Significant change to the Arctic and sub-arctic water cycle is underway, impacting hydrologic and biogeochemical fluxes. In southcentral Alaska, glacier mass loss, changes to precipitation (including the rain/snow fraction), thawing ground ice, and vegetation encroachment will change both magnitude and timing of water and solute fluxes downstream. Although altered fluxes of limiting nutrients are...Arctic Lake Food Webs
From 2011 to 2013 we investigated freshwater food webs of Arctic Coastal Plain lakes in Alaska to improve our understanding how Arctic freshwater food webs may respond to landscape change the warmer, drier future.Hydro-Ecology of Arctic Thawing (HEAT): Ecology
Permafrost thaw is leading to a myriad of changes in physical and chemical conditions throughout the Arctic.Wolverine Glacier Ecosystem Studies
This project is an extension of the long-term Wolverine Glacier Benchmark Glacier project and is improving our understanding of solutes and nutrients in glacier basins, and how they fuel downstream ecosystems.Matanuska-Susitna Borough Wetland Modeling
This project aims to improve our understanding of the role of wetlands in controlling streamflow in southcentral Alaska using a groundwater – surface water flow model that can recreate the dynamic interactions between streams and wetlands.Arctic Coastal Plain Studies
The Arctic Coastal Plain (ACP) is a large region of low-lying, lake-rich land on the North Slope of Alaska. This region is underlain by thick ground ice, which is susceptible to erosion and thaw. These physical changes are likely to alter ecosystems by changing the availability of habitats and food resources upon which wildlife depends. Our studies on the ACP aim to understand the link between... - Data
Filter Total Items: 25
Macroinvertebrates from Rivers in Northwest Alaska, 2015-2019
This dataset contains taxonomic information, counts, and lengths of macroinvertebrates collected from rivers in northwest Alaska using drift and kick nets during summer and fall 2015-2019.Hydrochemistry and Age Date Tracers from Springs, Streams, and Rivers in the Arctic National Wildlife Refuge, 2019-2022
These data include water chemistry from springs, streams, rivers, and shallow groundwater collected in the Arctic National Wildlife Refuge in northern Alaska. Chemical analyses were performed for hydrochemical parameters including field parameters, major ions, nutrients, metals, stable isotopes of water, and tritium, as well as for dissolved gases useful for determining the timescale over which thChemistry of Orange and Reference Streams in Northwestern Alaska
These data include water chemistry from headwater streams to large rivers that have recently turned orange and reference rivers that have not. These samples were collected in two national parks in Arctic Alaska: Kobuk Valley National Park, and Noatak National Preserve.Length, Weight, Energy Density, and Isotopic Values of Fish from Rivers in Northwest Alaska, 2015-2019
This dataset contains length, weight, energy density, and isotope values of fish collected in northwest Alaskan rivers during summer and fall 2015-2019.Macroinvertebrates From Streams and Springs in the 1002 Region of the Arctic National Wildlife Refuge, Alaska, 2021
This dataset includes tables related to macroinvertebrate collections in streams and springs of the 1002 region of the Arctic National Wildlife Refuge in northeastern Alaska. Macroinvertebrates were collected using kicknets and driftnets in April and August with the goal of comparing populations to those sampled from the same water bodies by the USGS in the 1970s.Frequency domain electromagnetic induction (FDEM) geophysical data collected near the Agashashok River in the Noatak National Preserve, AK
Frequency domain electromagnetic induction (FDEM) data were collected in September 2016 near the Agashashok River and its tributaries, within the Noatak National Preserve near Kotzebue, AK to aid in local permafrost mapping. Data were collected with a GEM-2 instrument (1.6 m coil separation, Geophex, Ltd.); a broadband sensor that measures the bulk conductivity and magnetic susceptibility of the sWater Level, Temperature, and Discharge in West Twin Creek, Alaska, 2010 to 2012
This data set includes 15-minute interval data on stream temperature, stage, and discharge from an upstream and downstream gaging location on West Twin Creek, a first-order tributary to Nome Creek in the White Mountains of Alaska.Stream and River Chemistry in Watersheds of Northwestern Alaska, 2015-2019
These data include stream water chemistry from headwater streams to large rivers across three national parks in Arctic Alaska: Bering Land Bridge National Preserve, Kobuk Valley National Park, and Noatak National Preserve.Stream Temperatures in the Noatak River and Kobuk River Basins, Northwest Alaska, 2017 - 2019
This data set includes 15-minute interval data on stream temperature from low-order streams and main-stem rivers in the Noatak and Kobuk River valleys in Northwestern Alaska, collected during the summer months. The water temperatures were determined using a HOBO Water Temp Pro v2 (Onset Computer Corporation, Bourne, MA, USA)with ±0.2 degrees C accuracy. Sensors were place in several locations withWetland Stream Water Quality Data for West Twin Creek, AK, Allequash Creek, WI, and Big Thompson River, CO, 2010-2020
This dataset includes discrete water quality and discharge data for three streams that flow through wetlands. There are two measurement and sampling locations on each stream: one immediately upstream from the wetland and one immediately downstream from the wetland. Measurements and sample collection occurred in 2010 and 2011 at West Twin Creek, AK; in 2019 and 2020 at Allequash Creek, WI; and in 2Geochemistry of Water Sources in the Wolverine Glacier Watershed, Alaska in 2016 and 2017
Glaciers are critical sources of water and solutes to downstream riverine and marine ecosystems. Samples were collected from surface streams, groundwater, rain, snow, and ice in the Wolverine Glacier basin and analyzed for a broad suite of geochemical constituents including common field parameters, major ions, stable isotopes of water, nutrients, metals, and dissolved organic carbon.Continuous Records of Shallow Soil Temperature and Moisture in the Noatak River Basin, Alaska
Soil moisture and temperature were measured at four shallow depths in multiple locations within tundra and forested landscapes of the Agashashok River basin. The measurements were made continuously beginning in 2015 until the most recent download in summer, 2019 or until the sensors or loggers failed. - Multimedia
Filter Total Items: 39An orange tributary of the Kugororuk River
Orange streams are increasingly common in the Brooks Range of northern Alaska. The orange stream color reflects oxidized iron, but also often indicates elevated heavy metal concentrations. Our ongoing study aims to document these occurrences and the timing of their onset.
Orange streams are increasingly common in the Brooks Range of northern Alaska. The orange stream color reflects oxidized iron, but also often indicates elevated heavy metal concentrations. Our ongoing study aims to document these occurrences and the timing of their onset.
An orange tributary joins the Kugaroruk RiverOrange streams are increasingly common in the Brooks Range of northern Alaska. The orange stream color reflects oxidized iron, but also often indicates elevated heavy metal concentrations. Our ongoing study aims to document these occurrences and the timing of their onset.
Orange streams are increasingly common in the Brooks Range of northern Alaska. The orange stream color reflects oxidized iron, but also often indicates elevated heavy metal concentrations. Our ongoing study aims to document these occurrences and the timing of their onset.
Limited mixing of orange water and the Kugororuk RiverLimited mixing of orange water and the Kugororuk RiverOrange streams are increasingly common in the Brooks Range of northern Alaska. The orange stream color reflects oxidized iron, but also often indicates elevated heavy metal concentrations. Our ongoing study aims to document these occurrences and the timing of their onset.
Orange streams are increasingly common in the Brooks Range of northern Alaska. The orange stream color reflects oxidized iron, but also often indicates elevated heavy metal concentrations. Our ongoing study aims to document these occurrences and the timing of their onset.
Orange water from a tributary of the Kugororuk RiverOrange water from a tributary of the Kugororuk RiverOrange streams are increasingly common in the Brooks Range of northern Alaska. The orange stream color reflects oxidized iron, but also often indicates elevated heavy metal concentrations. Our ongoing study aims to document these occurrences and the timing of their onset.
Orange streams are increasingly common in the Brooks Range of northern Alaska. The orange stream color reflects oxidized iron, but also often indicates elevated heavy metal concentrations. Our ongoing study aims to document these occurrences and the timing of their onset.
An orange tributary mixing into the pristine Kugaroruk RiverAn orange tributary mixing into the pristine Kugaroruk RiverOrange streams are increasingly common in the Brooks Range of northern Alaska. The orange stream color reflects oxidized iron, but also often indicates elevated heavy metal concentrations. Our ongoing study aims to document these occurrences and the timing of their onset.
Orange streams are increasingly common in the Brooks Range of northern Alaska. The orange stream color reflects oxidized iron, but also often indicates elevated heavy metal concentrations. Our ongoing study aims to document these occurrences and the timing of their onset.
The confluence of the Anakok River, Sheep Creek, and the Salmon RiverThe confluence of the Anakok River, Sheep Creek, and the Salmon RiverOrange streams are increasingly common in the Brooks Range of northern Alaska. The orange stream color reflects oxidized iron, but also often indicates elevated heavy metal concentrations. Our ongoing study aims to document these occurrences and the timing of their onset.
Orange streams are increasingly common in the Brooks Range of northern Alaska. The orange stream color reflects oxidized iron, but also often indicates elevated heavy metal concentrations. Our ongoing study aims to document these occurrences and the timing of their onset.
An orange tributary of the Anaktok RiverOrange streams are increasingly common in the Brooks Range of northern Alaska. The orange stream color reflects oxidized iron, but also often indicates elevated heavy metal concentrations. Our ongoing study aims to document these occurrences and the timing of their onset.
Orange streams are increasingly common in the Brooks Range of northern Alaska. The orange stream color reflects oxidized iron, but also often indicates elevated heavy metal concentrations. Our ongoing study aims to document these occurrences and the timing of their onset.
Orange flocullent on the bed of the Anaktok RiverOrange streams are increasingly common in the Brooks Range of northern Alaska. The orange stream color reflects oxidized iron, but also often indicates elevated heavy metal concentrations. Our ongoing study aims to document these occurrences and the timing of their onset.
Orange streams are increasingly common in the Brooks Range of northern Alaska. The orange stream color reflects oxidized iron, but also often indicates elevated heavy metal concentrations. Our ongoing study aims to document these occurrences and the timing of their onset.
Mixing of an orange tributary with clearer waters of the Anaktok RiverMixing of an orange tributary with clearer waters of the Anaktok RiverOrange streams are increasingly common in the Brooks Range of northern Alaska. The orange stream color reflects oxidized iron, but also often indicates elevated heavy metal concentrations. Our ongoing study aims to document these occurrences and the timing of their onset.
Orange streams are increasingly common in the Brooks Range of northern Alaska. The orange stream color reflects oxidized iron, but also often indicates elevated heavy metal concentrations. Our ongoing study aims to document these occurrences and the timing of their onset.
Orange staining along the Anaktok RiverOrange streams are increasingly common in the Brooks Range of northern Alaska. The orange stream color reflects oxidized iron, but also often indicates elevated heavy metal concentrations. Our ongoing study aims to document these occurrences and the timing of their onset.
Orange streams are increasingly common in the Brooks Range of northern Alaska. The orange stream color reflects oxidized iron, but also often indicates elevated heavy metal concentrations. Our ongoing study aims to document these occurrences and the timing of their onset.
Orange staining on snow in a braidplain of the Nakolikruk RiverOrange staining on snow in a braidplain of the Nakolikruk RiverOrange streams are increasingly common in the Brooks Range of northern Alaska. The orange stream color reflects oxidized iron, but also often indicates elevated heavy metal concentrations. Our ongoing study aims to document these occurrences and the timing of their onset.
Orange streams are increasingly common in the Brooks Range of northern Alaska. The orange stream color reflects oxidized iron, but also often indicates elevated heavy metal concentrations. Our ongoing study aims to document these occurrences and the timing of their onset.
Orange staining on snow below a seep on the Nakolikruk RiverOrange staining on snow below a seep on the Nakolikruk RiverOrange streams are increasingly common in the Brooks Range of northern Alaska. The orange stream color reflects oxidized iron, but also often indicates elevated heavy metal concentrations. Our ongoing study aims to document these occurrences and the timing of their onset.
Orange streams are increasingly common in the Brooks Range of northern Alaska. The orange stream color reflects oxidized iron, but also often indicates elevated heavy metal concentrations. Our ongoing study aims to document these occurrences and the timing of their onset.
Orange water and snow in a braidplain of the Nakolikruk RiverOrange water and snow in a braidplain of the Nakolikruk RiverOrange streams are increasingly common in the Brooks Range of northern Alaska. The orange stream color reflects oxidized iron, but also often indicates elevated heavy metal concentrations. Our ongoing study aims to document these occurrences and the timing of their onset.
Orange streams are increasingly common in the Brooks Range of northern Alaska. The orange stream color reflects oxidized iron, but also often indicates elevated heavy metal concentrations. Our ongoing study aims to document these occurrences and the timing of their onset.
Emergence of the Sadlerochit SpringThe Sadlerochit Spring is one of a handful of small springs that provides liquid water to the North Slope of Alaska year round. Given that most other water sources in this region are frozen in the winter, springs provide critical habitat for fish and macroinvertebrates, and may play an outsized role in the regions hydrologic cycle.
The Sadlerochit Spring is one of a handful of small springs that provides liquid water to the North Slope of Alaska year round. Given that most other water sources in this region are frozen in the winter, springs provide critical habitat for fish and macroinvertebrates, and may play an outsized role in the regions hydrologic cycle.
Ice-rich permafrost bluffs on the bank of the Canning River, AlaskaIce-rich permafrost bluffs on the bank of the Canning River, AlaskaIce-rich permafrost exerts a strong control on hydrology in Arctic regions because it limits infiltration, leading to large runoff events.
Ice-rich permafrost exerts a strong control on hydrology in Arctic regions because it limits infiltration, leading to large runoff events.
Gravel bar on the north fork of the Agashashok River, AlaskaGravel bar on the north fork of the Agashashok River, AlaskaA gravel bar on the north fork of the Agashashok River, Alaska. This work is part of the Hydro-Ecology of Arctic Thawing (HEAT): Hydrology project that takes place in the Arctic Network Parks because they lie in a region that is rapidly warming.
A gravel bar on the north fork of the Agashashok River, Alaska. This work is part of the Hydro-Ecology of Arctic Thawing (HEAT): Hydrology project that takes place in the Arctic Network Parks because they lie in a region that is rapidly warming.
A misty morning in the headwaters of the Akillik River, AlaskaA misty morning in the headwaters of the Akillik River, AlaskaA misty morning in the headwaters of the Akillik River, Alaska. This work is part of the Hydro-Ecology of Arctic Thawing (HEAT): Hydrology project that takes place in the Arctic Network Parks because they lie in a region that is rapidly warming.
A misty morning in the headwaters of the Akillik River, Alaska. This work is part of the Hydro-Ecology of Arctic Thawing (HEAT): Hydrology project that takes place in the Arctic Network Parks because they lie in a region that is rapidly warming.
A stream runs through ice-rich polygonal ground, Cutler River BasinA stream runs through ice-rich polygonal ground, Cutler River BasinA small stream meanders through ice-rich polygonal ground in the Cutler River Basin, Alaska. This work is part of the Hydro-Ecology of Arctic Thawing (HEAT): Hydrology project that takes place in the Arctic Network Parks because they lie in a region that
A small stream meanders through ice-rich polygonal ground in the Cutler River Basin, Alaska. This work is part of the Hydro-Ecology of Arctic Thawing (HEAT): Hydrology project that takes place in the Arctic Network Parks because they lie in a region that
Akilik River stream samplingHiking up a stream from the Akilik River drainage to set minnow traps for fish sampling. This is a stream type at the Boreal-Arctic transition of the Brooks Range, Noatak National Park and Preserve, Kobuk Valley National Park.
Hiking up a stream from the Akilik River drainage to set minnow traps for fish sampling. This is a stream type at the Boreal-Arctic transition of the Brooks Range, Noatak National Park and Preserve, Kobuk Valley National Park.
Flooding stream in a permafrost landscape, Kobuk Valley National ParkFlooding stream in a permafrost landscape, Kobuk Valley National ParkA flooding stream meanders through a permafrost landscape in Kobuk Valley National Park, Alaska. This work is part of the Hydro-Ecology of Arctic Thawing (HEAT): Hydrology project that takes place in the Arctic Network Parks because they lie in a region
A flooding stream meanders through a permafrost landscape in Kobuk Valley National Park, Alaska. This work is part of the Hydro-Ecology of Arctic Thawing (HEAT): Hydrology project that takes place in the Arctic Network Parks because they lie in a region
Agashashok River and Asik watershedThe Agashashok River and Asik watershed
The Agashashok River and Asik watershed
- Publications
Filter Total Items: 49
A high-resolution, daily hindcast (1990-2021) of Alaskan river discharge and temperature from coupled and optimized physical models
Water quality and freshwater ecosystems are affected by river discharge and temperature. Models are frequently used to estimate river temperature on large spatial and temporal scales due to limited observations of discharge and temperature. In this study, we use physically based river routing and temperature models to simulate daily discharge and river temperature for rivers in 138 basins in AlaskAuthorsDylan Blaskey, Michael Gooseff, Yifan Cheng, Andrew Newman, Joshua C. Koch, Keith MusselmanA comparison of contemporary and historical hydrology and water quality in the foothills and coastal plain of the Arctic National Wildlife Refuge, Arctic Slope, northern Alaska
The Arctic National Wildlife Refuge is a unique landscape in northern Alaska with limited water resources, substantial biodiversity of rare and threatened species, as well as oil and gas resources. The region has unique hydrology related to perennial springs, and the formation of large aufeis fields—sheets of ice that grow in the river channels where water reaches the surface in the winter and freAuthorsJoshua C. Koch, Heather Best, Carson Baughman, Charles Couvillion, Michael P. Carey, Jeff ConawaySeasonal and decadal subsurface thaw dynamics of an Aufeis feature investigated through numerical simulations
Aufeis (also known as icings) are large sheet-like masses of layered ice that form in river channels in arctic environments in the winter as groundwater discharges to the land surface and subsequently freezes. Aufeis are important sources of water for Arctic river ecosystems, bolstering late summer river discharge and providing habitat for caribou escaping insect harassment. The aim of this researAuthorsAlexi Lainis, Roseanna M. Neupauer, Joshua C. Koch, Michael GooseffThe Arctic Rivers Project: Using an equitable co-production framework for integrating meaningful community engagement and science to understand climate impacts
As the Arctic and its rivers continue to warm, a better understanding of the possible future impacts on people would benefit from close partnership with Indigenous communities and scientists from diverse fields of study. We present efforts by the Arctic Rivers Project to conduct community-engaged research to increase collective understanding of the historical and potential future impacts of climatAuthorsNicole M. Herman-Mercer, Alestine Andre, Victoria Buschman, Dylan Blaskey, Cassandra M. Brooks, Yifan Cheng, Evelynn Combs, Karen Cozzetto, Serena Fitka, Joshua C. Koch, Aine Lawlor, Elizabeth Moses, Emily Murray, Edda A. Mutter, Andrew Newman, Charles Prince, Patricia Salmon, Jenessa Tlen, Ryan C. Toohey, Michael L. Williams, Keith MusselmanComparing sediment microbial communities of Arctic beaver ponds to tundra lakes and streams
In recent decades the habitat of North American beaver (Castor canadensis) has expanded from boreal forests into Arctic tundra ecosystems. Beaver ponds in Arctic watersheds are known to alter stream biogeochemistry, which is likely coupled with changes in the activity and composition of microbial communities inhabiting beaver pond sediments. We investigated bacterial, archaeal, and fungal communitAuthorsKelly Shannon, Natasha R. Christman, Byron C. Crump, Michael P. Carey, Joshua C. Koch, Laura L. Lapham, Jonathan A. O'Donnell, Brett A. Poulin, Ken D. Tape, Jason A. Clark, Frederick S. ColwellIncreasing Alaskan river discharge during the cold season is driven by recent warming
Arctic hydrology is experiencing rapid changes including earlier snow melt, permafrost degradation, increasing active layer depth, and reduced river ice, all of which are expected to lead to changes in stream flow regimes. Recently, long-term (>60 years) climate reanalysis and river discharge observation data have become available. We utilized these data to assess long-term changes in discharge anAuthorsD Blaskey, Joshua C. Koch, M. Gooseff, A. C. Newman, Yang Cheng, Jonathan A. O'Donnell, K MusselmanIn hot water? Patterns of macroinvertebrate abundance in Arctic thaw ponds and relationships with environmental variables
Ongoing environmental change across the Arctic is affecting many freshwater ecosystems, including small thaw ponds that support macroinvertebrates, thus potentially affecting important forage for fish and bird species. To accurately predict how fish and wildlife that depend on these macroinvertebrates will be affected by ecosystem change at high latitudes, understanding proximate factors that inflAuthorsKirsty E. B. Gurney, Joshua C. Koch, Joel A. Schmutz, J. H. Schmidt, Mark S. WipfliEvaluating hydrologic region assignment techniques for ungaged basins in Alaska, USA
Building continental-scale hydrologic models in data-sparse regions requires an understanding of spatial variation in hydrologic processes. Extending these models to ungaged locations requires techniques to group ungaged locations with gaged ones to make process importance and model parameter transfer decisions to ungaged locations. This analysis (1) tested the utility of fundamental streamflow stAuthorsTheodore B. Barnhart, William H. Farmer, John C. Hammond, Graham A. Sexstone, Janet H. Curran, Joshua C. Koch, Jessica M. DriscollHow beavers are changing Arctic landscapes and Earth’s climate
Beavers build dams that change the way water moves between streams, lakes, and the land. In Alaska, beavers are moving north from the forests into the Arctic tundra. When beavers build dams in the Arctic, they cause frozen soil, called permafrost, to thaw. Scientists are studying how beavers and the thawing of permafrost are impacting streams and rivers in Alaska’s national parks. For example, perAuthorsJonathan A. O'Donnell, Michael P. Carey, Brett Poulin, Ken Tape, Joshua C. KochSensitivity of headwater streamflow to thawing permafrost and vegetation change in a warming Arctic
Climate change has the potential to impact headwater streams in the Arctic by thawing permafrost and subsequently altering hydrologic regimes and vegetation distribution, physiognomy and productivity. Permafrost thaw and increased subsurface flow have been inferred from the chemistry of large rivers, but there is limited empirical evidence of the impacts to headwater streams. Here we demonstrate hAuthorsJoshua C. Koch, Ylva Sjöberg, Jonathan A. O'Donnell, Michael P. Carey, Pamela Sullivan, A. TerskaiaHeterogeneous patterns of aged organic carbon export driven by hydrologic flow paths, soil texture, fire, and thaw in discontinuous permafrost headwaters
Climate change is thawing and potentially mobilizing vast quantities of organic carbon (OC) previously stored for millennia in permafrost soils of northern circumpolar landscapes. Climate-driven increases in fire and thermokarst may play a key role in OC mobilization by thawing permafrost and promoting transport of OC. Yet, the extent of OC mobilization and mechanisms controlling terrestrial-aquatAuthorsJoshua C. Koch, Matthew Bogard, David Butman, Kerri Finlay, Brian A. Ebel, Jason James, Sarah Ellen Johnston, Torre Jorgenson, Neal Pastick, Rob Spencer, Rob Striegl, Michelle A. Walvoord, Kimberly WicklandMulti-year, spatially extensive, watershed-scale synoptic stream chemistry and water quality conditions for six permafrost-underlain Arctic watersheds
Repeated sampling of spatially distributed river chemistry can be used to assess the location, scale, and persistence of carbon and nutrient contributions to watershed exports. Here, we provide a comprehensive set of water chemistry measurements and ecohydrological metrics describing the biogeochemical conditions of permafrost-affected Arctic watersheds. These data were collected in watershed-wideAuthorsArial Shogren, Jay P. Zarnetske, Benjamin Abbott, Samuel P. Bratsman, Brian C. Brown, Michael P. Carey, Randy Fulweiber, Heather Greaves, Emma Haines, Frances Iannucci, Joshua C. Koch, Alex Medvedeff, Jonathan A. O'Donnell, Leika Patch, Brett Poulin, Tanner J. Williamson, William B. Bowden - Web Tools
Arctic Rivers Project: Connecting Indigenous knowledge and western science to strengthen collective understanding of the changing Arctic
The Arctic Rivers Project will weave together Indigenous knowledges, monitoring, and the modeling of climate, rivers (flows, temperature, ice), and fish to improve understanding of how Arctic rivers, ice transportation corridors, fish, and communities might be impacted by and adapt to climate change.
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