Robert Striegl - Academia.edu (original) (raw)

Papers by Robert Striegl

Research paper thumbnail of Role of ground ice dynamics and ecological feedbacks in recent ice wedge degradation and stabilization

Ground ice is abundant in the upper permafrost throughout the Arctic and fundamentally affects te... more Ground ice is abundant in the upper permafrost throughout the Arctic and fundamentally affects terrain responses to climate warming. Ice wedges, which form near the surface and are the dominant type of massive ice in the Arctic, are particularly vulnerable to warming. Yet processes controlling ice wedge degradation and stabilization are poorly understood. Here we quantified ice wedge volume and degradation rates, compared ground ice characteristics and thermal regimes across a sequence of five degradation and stabilization stages and evaluated biophysical feedbacks controlling permafrost stability near Prudhoe Bay, Alaska. Mean ice wedge volume in the top 3 m of permafrost was 21%. Imagery from 1949 to 2012 showed thermokarst extent (area of water-filled troughs) was relatively small from 1949 (0.9%) to 1988 (1.5%), abruptly increased by 2004 (6.3%) and increased slightly by 2012 (7.5%). Mean annual surface temperatures varied by 4.9°C among degradation and stabilization stages and by 9.9°C from polygon center to deep lake bottom. Mean thicknesses of the active layer, ice-poor transient layer, ice-rich intermediate layer, thermokarst cave ice, and wedge ice varied substantially among stages. In early stages, thaw settlement caused water to impound in thermokarst troughs, creating positive feedbacks that increased net radiation, soil heat flux, and soil temperatures. Plant growth and organic matter accumulation in the degraded troughs provided negative feedbacks that allowed ground ice to aggrade and heave the surface, thus reducing surface water depth and soil temperatures in later stages. The ground ice dynamics and ecological feedbacks greatly complicate efforts to assess permafrost responses to climate change.

Research paper thumbnail of Estimating lake-atmosphere CO2 exchange

Limnology and Oceanography, 1999

Research paper thumbnail of Rates and Effects of Climate Warming and Permafrost Thawing in the Yukon River Basin: The Yukon Climate Effects Assessment and Monitoring Network

Research paper thumbnail of Plumbing the Global Carbon Cycle: Integrating Inland Waters into the Terrestrial Carbon Budget

Research paper thumbnail of Reorganization of vegetation, hydrology and soil carbon after permafrost degradation across heterogeneous boreal landscapes

Environmental Research Letters, 2013

Research paper thumbnail of Mercury in water and biomass of microbial communities in hot springs of Yellowstone National Park, USA

Applied Geochemistry, 2006

Research paper thumbnail of Uranium isotopes and dissolved organic carbon in loess permafrost: Modeling the age of ancient ice

Geochimica et Cosmochimica Acta, 2015

Research paper thumbnail of CO 2 dynamics in the Amargosa Desert: Fluxes and isotopic speciation in a deep unsaturated zone

Water Resources Research, 2005

Research paper thumbnail of Switching predominance of organic versus inorganic carbon exports from an intermediate-size subarctic watershed

Geophysical Research Letters, 2015

Research paper thumbnail of Transport of 14 CO 2 in Unsaturated Glacial and Eolian Sediments

ACS Symposium Series, 1990

Research paper thumbnail of A Whole Ecosystem Approach to Studying Climate Change in Interior Alaska

Eos, Transactions American Geophysical Union, 2011

ABSTRACT Yukon River Basin Principal Investigators Workshop; Portland, Oregon, 18-20 January 2011... more ABSTRACT Yukon River Basin Principal Investigators Workshop; Portland, Oregon, 18-20 January 2011; High latitudes are known to be particularly susceptible to climate warming, leading to an emphasis of field and modeling research on arctic regions. Subarctic and boreal regions such as the Yukon River Basin (YRB) of interior Alaska and western Canada are less well studied, although they encompass large areas that are vulnerable to changes in forest composition, permafrost distribution, and hydrology. There is an urgent need to understand the resiliency and vulnerability of these complex ecosystems as well as their feedbacks to the global climate system. Consequently, U.S. Geological Survey scientists, with other federal agency, university, and private industry partners, is focusing subarctic interdisciplinary studies on the Beaver Creek Wild and Scenic River watershed (http://www.blm.gov/pgdata/content/ak/en/prog/nlcs/beavercrk_nwsr.html) and Yukon Flats National Wildlife Refuge (http://yukonflats.fws.gov/) in the YRB, south and west of Fort Yukon, Alaska. These areas are national treasures of wetlands, lakes, and uplands that support large populations of wildlife and waterfowl and are home to vibrant native Alaskan communities that depend on the area for a subsistence lifestyle.

Research paper thumbnail of A positive relationship between groundwater velocity and submersed macrophyte biomass in Sparkling Lake Wisconsin

Limnology and Oceanography, 1989

... Sparkling Lake is a clear-water kettle lake in Vilas County in north-central Wisconsin (46?0&... more ... Sparkling Lake is a clear-water kettle lake in Vilas County in north-central Wisconsin (46?0'N, 89041 'W; Secchi depth, 6.6 m; pH 7.9; dissolved reactive P, 3.9 Ag liter-'; spe-cific conductance, 70 ,S cm-' (mean monthly data for 1983-1985 from JJ Mag-nuson). ... David M. Lodge ...

Research paper thumbnail of Carbon budget for a groundwater-fed lake: Calcification supports summer photosynthesis

Limnology and Oceanography, 1994

A chemical budget analysis for Williams Lake, Minnesota, tracks the seasonal progression of carbo... more A chemical budget analysis for Williams Lake, Minnesota, tracks the seasonal progression of carbon inputs and outputs. CO, exchanges with the atmosphere reverse seasonally, with uptake by the lake in summer preceded and followed by larger losses to the atmosphere. Calcium bicarbonate-rich groundwaters seep steadily into the lake, augmented by remobilization of lacustrine marls. Most of the carbon used in

Research paper thumbnail of Carbon dioxide partial pressure and 13C content of north temperate and boreal lakes at spring ice melt

Limnology and Oceanography, 2001

... samples were acidified to convert DIC to C02, and the headspace was analyzed by gas chromatog... more ... samples were acidified to convert DIC to C02, and the headspace was analyzed by gas chromatogra-phy-isotope mass spectrometry to determine 813CDIC (per mil relative to Pee Dee Belemnite; Fritz ... 37 Pa, which suggests few ter-restrial C inputs to these clearwater lakes. ...

Research paper thumbnail of Stubbins et al 2012 NGeo Glacier DOM supplemental

Research paper thumbnail of Emissions of carbon dioxide and methane from a headwater stream network of interior Alaska

Journal of Geophysical Research: Biogeosciences, 2013

Research paper thumbnail of Relations Between Quality of Urban Runoff and Quality of

Research paper thumbnail of High rates of air-water CO 2 exchange in saline lakes

Saline lakes comprise about a fifth of the total lake surface in the biosphere and include the la... more Saline lakes comprise about a fifth of the total lake surface in the biosphere and include the largest inland lake (the Caspian Sea) as well as many of the other largest lakes in the world (Aral Sea, Lake Chad, Lake Eyre; Williams 1993, Meybeck 1995). Most saline lakes , about 75 ...

Research paper thumbnail of Distribution of gases in the unsaturated zone near buried low-level radioactive waste

Research paper thumbnail of DIFFUSION OF RADIOACTIVE CARBON-DIOXIDE IN THE UNSATURATED ZONE NEAR BURIED LOW-LEVEL RADIOACTIVE-WASTE

Research paper thumbnail of Role of ground ice dynamics and ecological feedbacks in recent ice wedge degradation and stabilization

Ground ice is abundant in the upper permafrost throughout the Arctic and fundamentally affects te... more Ground ice is abundant in the upper permafrost throughout the Arctic and fundamentally affects terrain responses to climate warming. Ice wedges, which form near the surface and are the dominant type of massive ice in the Arctic, are particularly vulnerable to warming. Yet processes controlling ice wedge degradation and stabilization are poorly understood. Here we quantified ice wedge volume and degradation rates, compared ground ice characteristics and thermal regimes across a sequence of five degradation and stabilization stages and evaluated biophysical feedbacks controlling permafrost stability near Prudhoe Bay, Alaska. Mean ice wedge volume in the top 3 m of permafrost was 21%. Imagery from 1949 to 2012 showed thermokarst extent (area of water-filled troughs) was relatively small from 1949 (0.9%) to 1988 (1.5%), abruptly increased by 2004 (6.3%) and increased slightly by 2012 (7.5%). Mean annual surface temperatures varied by 4.9°C among degradation and stabilization stages and by 9.9°C from polygon center to deep lake bottom. Mean thicknesses of the active layer, ice-poor transient layer, ice-rich intermediate layer, thermokarst cave ice, and wedge ice varied substantially among stages. In early stages, thaw settlement caused water to impound in thermokarst troughs, creating positive feedbacks that increased net radiation, soil heat flux, and soil temperatures. Plant growth and organic matter accumulation in the degraded troughs provided negative feedbacks that allowed ground ice to aggrade and heave the surface, thus reducing surface water depth and soil temperatures in later stages. The ground ice dynamics and ecological feedbacks greatly complicate efforts to assess permafrost responses to climate change.

Research paper thumbnail of Estimating lake-atmosphere CO2 exchange

Limnology and Oceanography, 1999

Research paper thumbnail of Rates and Effects of Climate Warming and Permafrost Thawing in the Yukon River Basin: The Yukon Climate Effects Assessment and Monitoring Network

Research paper thumbnail of Plumbing the Global Carbon Cycle: Integrating Inland Waters into the Terrestrial Carbon Budget

Research paper thumbnail of Reorganization of vegetation, hydrology and soil carbon after permafrost degradation across heterogeneous boreal landscapes

Environmental Research Letters, 2013

Research paper thumbnail of Mercury in water and biomass of microbial communities in hot springs of Yellowstone National Park, USA

Applied Geochemistry, 2006

Research paper thumbnail of Uranium isotopes and dissolved organic carbon in loess permafrost: Modeling the age of ancient ice

Geochimica et Cosmochimica Acta, 2015

Research paper thumbnail of CO 2 dynamics in the Amargosa Desert: Fluxes and isotopic speciation in a deep unsaturated zone

Water Resources Research, 2005

Research paper thumbnail of Switching predominance of organic versus inorganic carbon exports from an intermediate-size subarctic watershed

Geophysical Research Letters, 2015

Research paper thumbnail of Transport of 14 CO 2 in Unsaturated Glacial and Eolian Sediments

ACS Symposium Series, 1990

Research paper thumbnail of A Whole Ecosystem Approach to Studying Climate Change in Interior Alaska

Eos, Transactions American Geophysical Union, 2011

ABSTRACT Yukon River Basin Principal Investigators Workshop; Portland, Oregon, 18-20 January 2011... more ABSTRACT Yukon River Basin Principal Investigators Workshop; Portland, Oregon, 18-20 January 2011; High latitudes are known to be particularly susceptible to climate warming, leading to an emphasis of field and modeling research on arctic regions. Subarctic and boreal regions such as the Yukon River Basin (YRB) of interior Alaska and western Canada are less well studied, although they encompass large areas that are vulnerable to changes in forest composition, permafrost distribution, and hydrology. There is an urgent need to understand the resiliency and vulnerability of these complex ecosystems as well as their feedbacks to the global climate system. Consequently, U.S. Geological Survey scientists, with other federal agency, university, and private industry partners, is focusing subarctic interdisciplinary studies on the Beaver Creek Wild and Scenic River watershed (http://www.blm.gov/pgdata/content/ak/en/prog/nlcs/beavercrk_nwsr.html) and Yukon Flats National Wildlife Refuge (http://yukonflats.fws.gov/) in the YRB, south and west of Fort Yukon, Alaska. These areas are national treasures of wetlands, lakes, and uplands that support large populations of wildlife and waterfowl and are home to vibrant native Alaskan communities that depend on the area for a subsistence lifestyle.

Research paper thumbnail of A positive relationship between groundwater velocity and submersed macrophyte biomass in Sparkling Lake Wisconsin

Limnology and Oceanography, 1989

... Sparkling Lake is a clear-water kettle lake in Vilas County in north-central Wisconsin (46?0&... more ... Sparkling Lake is a clear-water kettle lake in Vilas County in north-central Wisconsin (46?0'N, 89041 'W; Secchi depth, 6.6 m; pH 7.9; dissolved reactive P, 3.9 Ag liter-'; spe-cific conductance, 70 ,S cm-' (mean monthly data for 1983-1985 from JJ Mag-nuson). ... David M. Lodge ...

Research paper thumbnail of Carbon budget for a groundwater-fed lake: Calcification supports summer photosynthesis

Limnology and Oceanography, 1994

A chemical budget analysis for Williams Lake, Minnesota, tracks the seasonal progression of carbo... more A chemical budget analysis for Williams Lake, Minnesota, tracks the seasonal progression of carbon inputs and outputs. CO, exchanges with the atmosphere reverse seasonally, with uptake by the lake in summer preceded and followed by larger losses to the atmosphere. Calcium bicarbonate-rich groundwaters seep steadily into the lake, augmented by remobilization of lacustrine marls. Most of the carbon used in

Research paper thumbnail of Carbon dioxide partial pressure and 13C content of north temperate and boreal lakes at spring ice melt

Limnology and Oceanography, 2001

... samples were acidified to convert DIC to C02, and the headspace was analyzed by gas chromatog... more ... samples were acidified to convert DIC to C02, and the headspace was analyzed by gas chromatogra-phy-isotope mass spectrometry to determine 813CDIC (per mil relative to Pee Dee Belemnite; Fritz ... 37 Pa, which suggests few ter-restrial C inputs to these clearwater lakes. ...

Research paper thumbnail of Stubbins et al 2012 NGeo Glacier DOM supplemental

Research paper thumbnail of Emissions of carbon dioxide and methane from a headwater stream network of interior Alaska

Journal of Geophysical Research: Biogeosciences, 2013

Research paper thumbnail of Relations Between Quality of Urban Runoff and Quality of

Research paper thumbnail of High rates of air-water CO 2 exchange in saline lakes

Saline lakes comprise about a fifth of the total lake surface in the biosphere and include the la... more Saline lakes comprise about a fifth of the total lake surface in the biosphere and include the largest inland lake (the Caspian Sea) as well as many of the other largest lakes in the world (Aral Sea, Lake Chad, Lake Eyre; Williams 1993, Meybeck 1995). Most saline lakes , about 75 ...

Research paper thumbnail of Distribution of gases in the unsaturated zone near buried low-level radioactive waste

Research paper thumbnail of DIFFUSION OF RADIOACTIVE CARBON-DIOXIDE IN THE UNSATURATED ZONE NEAR BURIED LOW-LEVEL RADIOACTIVE-WASTE