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
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Effects of permafrost thaw on CO2 and CH4 exchange in a western Alaska peatland chronosequence Effects of permafrost thaw on CO2 and CH4 exchange in a western Alaska peatland chronosequence
Permafrost soils store over half of global soil carbon (C), and northern frozen peatlands store about 10% of global permafrost C. With thaw, inundation of high latitude lowland peatlands typically increases the surface-atmosphere flux of methane (CH4), a potent greenhouse gas. To examine the effects of lowland permafrost thaw over millennial timescales, we measured carbon dioxide (CO2)...
Authors
Carmel Johnston, Stephanie Ewing, Jennifer Harden, Ruth K. Varner, Kimberly Wickland, Joshua Koch, Christopher Fuller, Kristen Manies, M. Jorgenson
Thermokarst and thaw-related landscape dynamics -- an annotated bibliography with an emphasis on potential effects on habitat and wildlife Thermokarst and thaw-related landscape dynamics -- an annotated bibliography with an emphasis on potential effects on habitat and wildlife
Permafrost has warmed throughout much of the Northern Hemisphere since the 1980s, with colder permafrost sites warming more rapidly (Romanovsky and others, 2010; Smith and others, 2010). Warming of the near-surface permafrost may lead to widespread terrain instability in ice-rich permafrost in the Arctic and the Subarctic, and may result in thermokarst development and other thaw-related...
Authors
Benjamin Jones, Courtney Amundson, Joshua Koch, Guido Grosse
Hydrologic controls on the transport and cycling of carbon and nitrogen in a boreal catchment underlain by continuous permafrost Hydrologic controls on the transport and cycling of carbon and nitrogen in a boreal catchment underlain by continuous permafrost
Boreal ecosystems represent a large carbon (C) reservoir and a substantial source of greenhouse gases. Hydrologic conditions dictate whether C leached from boreal soils is processed in catchments or flushed to less productive environments via the stream. This study quantified hydrologic and biogeochemical C loss from a boreal catchment underlain by frozen silt, where flowpaths may deepen...
Authors
Joshua Koch, Robert Runkel, Robert Striegl, Diane McKnight
Review: groundwater in Alaska (USA) Review: groundwater in Alaska (USA)
Groundwater in the US state of Alaska is critical to both humans and ecosystems. Interactions among physiography, ecology, geology, and current and past climate have largely determined the location and properties of aquifers as well as the timing and magnitude of fluxes to, from, and within the groundwater system. The climate ranges from maritime in the southern portion of the state to...
Authors
J.B. Callegary, C.P. Kikuchi, Joshua Koch, M. Lilly, S. Leake
Rapid runoff via shallow throughflow and deeper preferential flow in a boreal catchment underlain by frozen silt (Alaska, USA) Rapid runoff via shallow throughflow and deeper preferential flow in a boreal catchment underlain by frozen silt (Alaska, USA)
In high-latitude catchments where permafrost is present, runoff dynamics are complicated by seasonal active-layer thaw, which may cause a change in the dominant flowpaths as water increasingly contacts mineral soils of low hydraulic conductivity. A 2-year study, conducted in an upland catchment in Alaska (USA) underlain by frozen, well-sorted eolian silt, examined changes in infiltration...
Authors
Joshua Koch, Stephanie Ewing, Robert Striegl, Diane McKnight
Reorganization of vegetation, hydrology and soil carbon after permafrost degradation across heterogeneous boreal landscapes Reorganization of vegetation, hydrology and soil carbon after permafrost degradation across heterogeneous boreal landscapes
The diversity of ecosystems across boreal landscapes, successional changes after disturbance and complicated permafrost histories, present enormous challenges for assessing how vegetation, water and soil carbon may respond to climate change in boreal regions. To address this complexity, we used a chronosequence approach to assess changes in vegetation composition, water storage and soil...
Authors
M. Torre Jorgenson, Jennifer Harden, Mikhail Kanevskiy, Jonathan O'Donnell, Kim Wickland, Stephanie Ewing, Kristen Manies, Qianlai Zhuang, Yuri Shur, Robert Striegl, Joshua Koch
Changing Arctic ecosystems - measuring and forecasting the response of Alaska's terrestrial ecosystem to a warming climate Changing Arctic ecosystems - measuring and forecasting the response of Alaska's terrestrial ecosystem to a warming climate
The Arctic Coastal Plain of northern Alaska is a complex landscape of lakes, streams, and wetlands scattered across low relief tundra that is underlain by permafrost. This region of the Arctic has experienced a warming trend over the past three decades, leading to thawing of on-shore permafrost and the disappearance of sea ice at an unprecedented rate. The loss of sea ice has increased...
Authors
John Pearce, Anthony DeGange, Paul Flint, Tom Fondell, David Gustine, Leslie Holland-Bartels, Andrew Hope, Jerry Hupp, Joshua Koch, Joel Schmutz, Sandra Talbot, David Ward, Mary Whalen
Thermal and hydrological observations near Twelvemile Lake in discontinuous permafrost, Yukon Flats, interior Alaska, September 2010-August 2011 Thermal and hydrological observations near Twelvemile Lake in discontinuous permafrost, Yukon Flats, interior Alaska, September 2010-August 2011
A series of ground-based observations were made between September 2010 and August 2011 near Twelvemile Lake, 19 kilometers southwest of Fort Yukon, Alaska, for use in ongoing hydrological analyses of watersheds in this region of discontinuous permafrost. Measurements include depth to ground ice, depth to water table, soil texture, soil moisture, soil temperature, and water pressure above...
Authors
Steven Jepsen, Joshua Koch, Joshua Rose, Clifford Voss, Michelle Walvoord
Science and Products
Filter Total Items: 17
Filter Total Items: 30
No Result Found
Filter Total Items: 41
No results found.
Filter Total Items: 56
Effects of permafrost thaw on CO2 and CH4 exchange in a western Alaska peatland chronosequence Effects of permafrost thaw on CO2 and CH4 exchange in a western Alaska peatland chronosequence
Permafrost soils store over half of global soil carbon (C), and northern frozen peatlands store about 10% of global permafrost C. With thaw, inundation of high latitude lowland peatlands typically increases the surface-atmosphere flux of methane (CH4), a potent greenhouse gas. To examine the effects of lowland permafrost thaw over millennial timescales, we measured carbon dioxide (CO2)...
Authors
Carmel Johnston, Stephanie Ewing, Jennifer Harden, Ruth K. Varner, Kimberly Wickland, Joshua Koch, Christopher Fuller, Kristen Manies, M. Jorgenson
Thermokarst and thaw-related landscape dynamics -- an annotated bibliography with an emphasis on potential effects on habitat and wildlife Thermokarst and thaw-related landscape dynamics -- an annotated bibliography with an emphasis on potential effects on habitat and wildlife
Permafrost has warmed throughout much of the Northern Hemisphere since the 1980s, with colder permafrost sites warming more rapidly (Romanovsky and others, 2010; Smith and others, 2010). Warming of the near-surface permafrost may lead to widespread terrain instability in ice-rich permafrost in the Arctic and the Subarctic, and may result in thermokarst development and other thaw-related...
Authors
Benjamin Jones, Courtney Amundson, Joshua Koch, Guido Grosse
Hydrologic controls on the transport and cycling of carbon and nitrogen in a boreal catchment underlain by continuous permafrost Hydrologic controls on the transport and cycling of carbon and nitrogen in a boreal catchment underlain by continuous permafrost
Boreal ecosystems represent a large carbon (C) reservoir and a substantial source of greenhouse gases. Hydrologic conditions dictate whether C leached from boreal soils is processed in catchments or flushed to less productive environments via the stream. This study quantified hydrologic and biogeochemical C loss from a boreal catchment underlain by frozen silt, where flowpaths may deepen...
Authors
Joshua Koch, Robert Runkel, Robert Striegl, Diane McKnight
Review: groundwater in Alaska (USA) Review: groundwater in Alaska (USA)
Groundwater in the US state of Alaska is critical to both humans and ecosystems. Interactions among physiography, ecology, geology, and current and past climate have largely determined the location and properties of aquifers as well as the timing and magnitude of fluxes to, from, and within the groundwater system. The climate ranges from maritime in the southern portion of the state to...
Authors
J.B. Callegary, C.P. Kikuchi, Joshua Koch, M. Lilly, S. Leake
Rapid runoff via shallow throughflow and deeper preferential flow in a boreal catchment underlain by frozen silt (Alaska, USA) Rapid runoff via shallow throughflow and deeper preferential flow in a boreal catchment underlain by frozen silt (Alaska, USA)
In high-latitude catchments where permafrost is present, runoff dynamics are complicated by seasonal active-layer thaw, which may cause a change in the dominant flowpaths as water increasingly contacts mineral soils of low hydraulic conductivity. A 2-year study, conducted in an upland catchment in Alaska (USA) underlain by frozen, well-sorted eolian silt, examined changes in infiltration...
Authors
Joshua Koch, Stephanie Ewing, Robert Striegl, Diane McKnight
Reorganization of vegetation, hydrology and soil carbon after permafrost degradation across heterogeneous boreal landscapes Reorganization of vegetation, hydrology and soil carbon after permafrost degradation across heterogeneous boreal landscapes
The diversity of ecosystems across boreal landscapes, successional changes after disturbance and complicated permafrost histories, present enormous challenges for assessing how vegetation, water and soil carbon may respond to climate change in boreal regions. To address this complexity, we used a chronosequence approach to assess changes in vegetation composition, water storage and soil...
Authors
M. Torre Jorgenson, Jennifer Harden, Mikhail Kanevskiy, Jonathan O'Donnell, Kim Wickland, Stephanie Ewing, Kristen Manies, Qianlai Zhuang, Yuri Shur, Robert Striegl, Joshua Koch
Changing Arctic ecosystems - measuring and forecasting the response of Alaska's terrestrial ecosystem to a warming climate Changing Arctic ecosystems - measuring and forecasting the response of Alaska's terrestrial ecosystem to a warming climate
The Arctic Coastal Plain of northern Alaska is a complex landscape of lakes, streams, and wetlands scattered across low relief tundra that is underlain by permafrost. This region of the Arctic has experienced a warming trend over the past three decades, leading to thawing of on-shore permafrost and the disappearance of sea ice at an unprecedented rate. The loss of sea ice has increased...
Authors
John Pearce, Anthony DeGange, Paul Flint, Tom Fondell, David Gustine, Leslie Holland-Bartels, Andrew Hope, Jerry Hupp, Joshua Koch, Joel Schmutz, Sandra Talbot, David Ward, Mary Whalen
Thermal and hydrological observations near Twelvemile Lake in discontinuous permafrost, Yukon Flats, interior Alaska, September 2010-August 2011 Thermal and hydrological observations near Twelvemile Lake in discontinuous permafrost, Yukon Flats, interior Alaska, September 2010-August 2011
A series of ground-based observations were made between September 2010 and August 2011 near Twelvemile Lake, 19 kilometers southwest of Fort Yukon, Alaska, for use in ongoing hydrological analyses of watersheds in this region of discontinuous permafrost. Measurements include depth to ground ice, depth to water table, soil texture, soil moisture, soil temperature, and water pressure above...
Authors
Steven Jepsen, Joshua Koch, Joshua Rose, Clifford Voss, Michelle Walvoord
*Disclaimer: Listing outside positions with professional scientific organizations on this Staff Profile are for informational purposes only and do not constitute an endorsement of those professional scientific organizations or their activities by the USGS, Department of the Interior, or U.S. Government