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Full-Text Articles in Physical Sciences and Mathematics

Trapped Under Ice: Spatial And Seasonal Dynamics Of Dissolved Organic Matter Composition In Tundra Lakes, Martin R. Kurek, Karen E. Frey, François Guillemette, David C. Podgorski, Amy Townsend-Small, Christopher D. Arp, Anne M. Kellerman, Robert G.M. Spencer Jan 2022

Trapped Under Ice: Spatial And Seasonal Dynamics Of Dissolved Organic Matter Composition In Tundra Lakes, Martin R. Kurek, Karen E. Frey, François Guillemette, David C. Podgorski, Amy Townsend-Small, Christopher D. Arp, Anne M. Kellerman, Robert G.M. Spencer

Geography

Arctic lakes store, modify, and transport large quantities of carbon from terrestrial environments to the atmosphere; however, the spatial and temporal relationships between quantity and composition of dissolved organic matter (DOM) have not been well characterized across broad arctic regions. Moreover, most arctic lake DOM compositions have been examined during the ice-free summer, whereas DOM cycling between the ice-covered winter months and summer have not been addressed. To resolve these spatial and seasonal uncertainties in DOM cycling, we sampled a series of arctic lakes from the North Slope of Alaska across a latitudinal gradient in the winter and summer over …


First Pan-Arctic Assessment Of Dissolved Organic Carbon In Lakes Of The Permafrost Region, Lydia Stolpmann, Caroline Coch, Anne Morgenstern, Julia Boike, Michael Fritz, Ulrike Herzschuh, Kathleen Stoof-Leichsenring, Yury Dvornikov, Birgit Heim, Josefine Lenz, Amy Larsen, Katey Walter Anthony, Benjamin Jones, Karen Frey, Guido Grosse Jan 2021

First Pan-Arctic Assessment Of Dissolved Organic Carbon In Lakes Of The Permafrost Region, Lydia Stolpmann, Caroline Coch, Anne Morgenstern, Julia Boike, Michael Fritz, Ulrike Herzschuh, Kathleen Stoof-Leichsenring, Yury Dvornikov, Birgit Heim, Josefine Lenz, Amy Larsen, Katey Walter Anthony, Benjamin Jones, Karen Frey, Guido Grosse

Geography

Lakes in permafrost regions are dynamic landscape components and play an important role for climate change feedbacks. Lake processes such as mineralization and flocculation of dissolved organic carbon (DOC), one of the main carbon fractions in lakes, contribute to the greenhouse effect and are part of the global carbon cycle. These processes are in the focus of climate research, but studies so far are limited to specific study regions. In our synthesis, we analyzed 2167 water samples from 1833 lakes across the Arctic in permafrost regions of Alaska, Canada, Greenland, and Siberia to provide first pan-Arctic insights for linkages between …


Variation In Summer Nitrogen And Phosphorus Uptake Among Siberian Headwater Streams, John D. Schade, Erin C. Seybold, Travis Drake, Seth Spawn, William V. Sobczak, Karen E. Frey, Robert M. Holmes, Nikita Zimov Jan 2016

Variation In Summer Nitrogen And Phosphorus Uptake Among Siberian Headwater Streams, John D. Schade, Erin C. Seybold, Travis Drake, Seth Spawn, William V. Sobczak, Karen E. Frey, Robert M. Holmes, Nikita Zimov

Geography

Arctic streams are likely to receive increased inputs of dissolved nutrients and organic matter from thawing permafrost as climate warms. Documenting how Arctic streams process inorganic nutrients is necessary to understand mechanisms that regulate watershed fluxes of permafrost-derived materials to downstream ecosystems. We report on summer nitrogen (N) and phosphorus (P) uptake in streams draining upland soils from the Pleistocene, and lowland floodplain soils from the Holocene, in Siberia's Kolyma River watershed. Uptake of N and P differed between upland and floodplain streams, suggesting topographic variation in nutrient limitation. In floodplain streams, P uptake rate and uptake velocity were higher …


Optical Properties And Bioavailability Of Dissolved Organic Matter Along A Flow-Path Continuum From Soil Pore Waters To The Kolyma River Mainstem, East Siberia, Karen E. Frey, William V. Sobczak, Paul J. Mann, Robert M. Holmes Jan 2016

Optical Properties And Bioavailability Of Dissolved Organic Matter Along A Flow-Path Continuum From Soil Pore Waters To The Kolyma River Mainstem, East Siberia, Karen E. Frey, William V. Sobczak, Paul J. Mann, Robert M. Holmes

Geography

The Kolyma River in northeast Siberia is among the six largest Arctic rivers and drains a region underlain by vast deposits of Holocene-aged peat and Pleistocene-aged loess known as yedoma, most of which is currently stored in ice-rich permafrost throughout the region. These peat and yedoma deposits are important sources of dissolved organic matter (DOM) to inland waters that in turn play a significant role in the transport and ultimate remineralization of organic carbon to CO2 and CH4 along the terrestrial flow-path continuum. The turnover and fate of terrigenous DOM during offshore transport largely depends upon the composition and amount …


Summer Co2 Evasion From Streams And Rivers In The Kolyma River Basin, North-East Siberia, Blaize A. Denfeld, Karen E. Frey, William V. Sobczak, Paul J. Mann, Robert M. Holmes Jan 2013

Summer Co2 Evasion From Streams And Rivers In The Kolyma River Basin, North-East Siberia, Blaize A. Denfeld, Karen E. Frey, William V. Sobczak, Paul J. Mann, Robert M. Holmes

Geography

Inland water systems are generally supersaturated in carbon dioxide (CO2) and are increasingly recognized as playing an important role in the global carbon cycle. The Arctic may be particularly important in this respect, given the abundance of inland waters and carbon contained in Arctic soils; however, a lack of trace gas measurements from small streams in the Arctic currently limits this understanding.We investigated the spatial variability of CO2 evasion during the summer low-flow period from streams and rivers in the northern portion of the Kolyma River basin in north-eastern Siberia. To this end, partial pressure of carbon dioxide (pCO2) and …


Landscape-Level Controls On Dissolved Carbon Flux From Diverse Catchments Of The Circumboreal, Suzanne E. Tank, Karen E. Frey, Robert G. Striegl, Peter A. Raymond, Robert M. Holmes, James W. Mcclelland, Bruce J. Peterson Jan 2012

Landscape-Level Controls On Dissolved Carbon Flux From Diverse Catchments Of The Circumboreal, Suzanne E. Tank, Karen E. Frey, Robert G. Striegl, Peter A. Raymond, Robert M. Holmes, James W. Mcclelland, Bruce J. Peterson

Geography

While much of the dissolved organic carbon (DOC) within rivers is destined for mineralization to CO2, a substantial fraction of riverine bicarbonate (HCO3-) flux represents a CO2 sink, as a result of weathering processes that sequester CO2 as HCO 3-. We explored landscape-level controls on DOC and HCO3- flux in subcatchments of the boreal, with a specific focus on the effect of permafrost on riverine dissolved C flux. To do this, we undertook a multivariate analysis that partitioned the variance attributable to known, key regulators of dissolved C flux (runoff, lithology, and vegetation) prior to examining the effect of permafrost, …


Geochemistry Of West Siberian Streams And Their Potential Response To Permafrost Degradation, Karen E. Frey, Donald I. Siegel, Laurence C. Smith Jan 2007

Geochemistry Of West Siberian Streams And Their Potential Response To Permafrost Degradation, Karen E. Frey, Donald I. Siegel, Laurence C. Smith

Geography

[1] Measurements of solute concentrations from previously unstudied watersheds throughout west Siberia suggest that warming and permafrost degradation will likely amplify the transport of dissolved solids to the Kara Sea and adjacent Arctic Ocean. We present concentrations of Ca2+, K+, Mg2+, Na+, Si, Cl-, SO 42-, HCO3-, inferred alkalinity, and total inorganic solutes (TIS) from 94 streams and rivers within the Ob'-Irtysh, Nadym, and Pur river drainage basins. The sampled sites span ∼10 6 km2, a large climatic gradient (∼55°-68°N), and 39 permafrost-influenced and 55 permafrost-free watersheds. The solute composition of our samples is strongly influenced by carbonate mineral dissolution. …