John Pohlman, PhD
John Pohlman is a Research Chemist with the Woods Hole Coastal and Marine Science Center Gas Hydrates Project.
Science and Products
Filter Total Items: 62
An intercomparison of oceanic methane and nitrous oxide measurements An intercomparison of oceanic methane and nitrous oxide measurements
Large-scale climatic forcing is impacting oceanic biogeochemical cycles and is expected to influence the water-column distribution of trace gases, including methane and nitrous oxide. Our ability as a scientific community to evaluate changes in the water-column inventories of methane and nitrous oxide depends largely on our capacity to obtain robust and accurate concentration...
Authors
Samuel Wilson, Hermann Bange, Damian Arevalo-Martinez, Jonathan Barnes, Alberto V. Borges, Ian Brown, John Bullister, Macarena Burgos, David Capelle, Michael Casso, Mercedes de la Paz, Laura Farias, Lindsay Fenwick, Sara Ferron, Gerardo Garcia, MIchael Glockzin, David Karl, Annette Kock, Sarah Laperriere, Cliff S. Law, Cara Manning, Andrew Marriner, Jukka-Pekka Myllykangas, John Pohlman, Andrew Rees, Allison Santoro, Philippe Tortll, Robert C. Upstill-Goddard, David Wisegarver, Gui-Ling Zhang, Gregor Rehder
Greenhouse gas emissions from diverse Arctic Alaskan lakes are dominated by young carbon Greenhouse gas emissions from diverse Arctic Alaskan lakes are dominated by young carbon
Climate-sensitive Arctic lakes have been identified as conduits for ancient permafrost-carbon (C) emissions and as such accelerate warming. However, the environmental factors that control emission pathways and their sources are unclear; this complicates upscaling, forecasting and climate-impact-assessment efforts. Here we show that current whole-lake CH4 and CO2 emissions from widespread...
Authors
Clayton D. Elder, Xiaomei Xu, Jennifer Walker, Jordan L. Schnell, Kenneth M. Hinkel, Amy Townsend-Small, Christopher D. Arp, John W. Pohlman, Benjamin V. Gaglioti, Claudia I. Czimzik
Exudation rates and δ13C signatures of tree root soluble organic carbon in a riparian forest Exudation rates and δ13C signatures of tree root soluble organic carbon in a riparian forest
Tree root exudation (TRE) of water soluble organic carbon (WSOC) is an important but under-assessed component of net primary production, and is thought to strongly influence rhizosphere biogeochemistry. Riparian systems in particular are often viewed as biogeochemical hot spots fueled partially by root exudate WSOC. However, TRE rates have not been previously reported for these systems...
Authors
S. W. Gougherty, J. E. Bauer, J. W. Pohlman
Methane- and dissolved organic carbon-fueled microbial loop supports a tropical subterranean estuary ecosystem Methane- and dissolved organic carbon-fueled microbial loop supports a tropical subterranean estuary ecosystem
Subterranean estuaries extend inland into density-stratified coastal carbonate aquifers containing a surprising diversity of endemic animals (mostly crustaceans) within a highly oligotrophic habitat. How complex ecosystems (termed anchialine) thrive in this globally distributed, cryptic environment is poorly understood. Here, we demonstrate that a microbial loop shuttles methane and...
Authors
D. Brankovits, John W. Pohlman, H. Niemann, M.B. Leigh, M.C. Leewis, K. W. Becker, T.M. Iliffe, Alvarez. F., M.F. Lehmann, B. Phillips
Enhanced CO2 uptake at a shallow Arctic Ocean seep field overwhelms the positive warming potential of emitted methane Enhanced CO2 uptake at a shallow Arctic Ocean seep field overwhelms the positive warming potential of emitted methane
Continued warming of the Arctic Ocean in coming decades is projected to trigger the release of teragrams (1 Tg = 106 tons) of methane from thawing subsea permafrost on shallow continental shelves and dissociation of methane hydrate on upper continental slopes. On the shallow shelves (
Authors
John W. Pohlman, J. Greinert, Carolyn D. Ruppel, A Silyakova, L Vielstadte, Michael Casso, J Mienert, S Bunz
Methane turnover and environmental change from Holocene biomarker records in a thermokarst lake in Arctic Alaska Methane turnover and environmental change from Holocene biomarker records in a thermokarst lake in Arctic Alaska
Arctic lakes and wetlands contribute a substantial amount of methane to the contemporary atmosphere, yet profound knowledge gaps remain regarding the intensity and climatic control of past methane emissions from this source. In this study, we reconstruct methane turnover and environmental conditions, including estimates of mean annual and summer temperature, from a thermokarst lake (Lake...
Authors
Marcus Elvert, John W. Pohlman, Kevin W. Becker, Benjamin V. Gaglioti, Kai-Uwe Hinrichs, Matthew J. Wooller
Science and Products
Filter Total Items: 62
An intercomparison of oceanic methane and nitrous oxide measurements An intercomparison of oceanic methane and nitrous oxide measurements
Large-scale climatic forcing is impacting oceanic biogeochemical cycles and is expected to influence the water-column distribution of trace gases, including methane and nitrous oxide. Our ability as a scientific community to evaluate changes in the water-column inventories of methane and nitrous oxide depends largely on our capacity to obtain robust and accurate concentration...
Authors
Samuel Wilson, Hermann Bange, Damian Arevalo-Martinez, Jonathan Barnes, Alberto V. Borges, Ian Brown, John Bullister, Macarena Burgos, David Capelle, Michael Casso, Mercedes de la Paz, Laura Farias, Lindsay Fenwick, Sara Ferron, Gerardo Garcia, MIchael Glockzin, David Karl, Annette Kock, Sarah Laperriere, Cliff S. Law, Cara Manning, Andrew Marriner, Jukka-Pekka Myllykangas, John Pohlman, Andrew Rees, Allison Santoro, Philippe Tortll, Robert C. Upstill-Goddard, David Wisegarver, Gui-Ling Zhang, Gregor Rehder
Greenhouse gas emissions from diverse Arctic Alaskan lakes are dominated by young carbon Greenhouse gas emissions from diverse Arctic Alaskan lakes are dominated by young carbon
Climate-sensitive Arctic lakes have been identified as conduits for ancient permafrost-carbon (C) emissions and as such accelerate warming. However, the environmental factors that control emission pathways and their sources are unclear; this complicates upscaling, forecasting and climate-impact-assessment efforts. Here we show that current whole-lake CH4 and CO2 emissions from widespread...
Authors
Clayton D. Elder, Xiaomei Xu, Jennifer Walker, Jordan L. Schnell, Kenneth M. Hinkel, Amy Townsend-Small, Christopher D. Arp, John W. Pohlman, Benjamin V. Gaglioti, Claudia I. Czimzik
Exudation rates and δ13C signatures of tree root soluble organic carbon in a riparian forest Exudation rates and δ13C signatures of tree root soluble organic carbon in a riparian forest
Tree root exudation (TRE) of water soluble organic carbon (WSOC) is an important but under-assessed component of net primary production, and is thought to strongly influence rhizosphere biogeochemistry. Riparian systems in particular are often viewed as biogeochemical hot spots fueled partially by root exudate WSOC. However, TRE rates have not been previously reported for these systems...
Authors
S. W. Gougherty, J. E. Bauer, J. W. Pohlman
Methane- and dissolved organic carbon-fueled microbial loop supports a tropical subterranean estuary ecosystem Methane- and dissolved organic carbon-fueled microbial loop supports a tropical subterranean estuary ecosystem
Subterranean estuaries extend inland into density-stratified coastal carbonate aquifers containing a surprising diversity of endemic animals (mostly crustaceans) within a highly oligotrophic habitat. How complex ecosystems (termed anchialine) thrive in this globally distributed, cryptic environment is poorly understood. Here, we demonstrate that a microbial loop shuttles methane and...
Authors
D. Brankovits, John W. Pohlman, H. Niemann, M.B. Leigh, M.C. Leewis, K. W. Becker, T.M. Iliffe, Alvarez. F., M.F. Lehmann, B. Phillips
Enhanced CO2 uptake at a shallow Arctic Ocean seep field overwhelms the positive warming potential of emitted methane Enhanced CO2 uptake at a shallow Arctic Ocean seep field overwhelms the positive warming potential of emitted methane
Continued warming of the Arctic Ocean in coming decades is projected to trigger the release of teragrams (1 Tg = 106 tons) of methane from thawing subsea permafrost on shallow continental shelves and dissociation of methane hydrate on upper continental slopes. On the shallow shelves (
Authors
John W. Pohlman, J. Greinert, Carolyn D. Ruppel, A Silyakova, L Vielstadte, Michael Casso, J Mienert, S Bunz
Methane turnover and environmental change from Holocene biomarker records in a thermokarst lake in Arctic Alaska Methane turnover and environmental change from Holocene biomarker records in a thermokarst lake in Arctic Alaska
Arctic lakes and wetlands contribute a substantial amount of methane to the contemporary atmosphere, yet profound knowledge gaps remain regarding the intensity and climatic control of past methane emissions from this source. In this study, we reconstruct methane turnover and environmental conditions, including estimates of mean annual and summer temperature, from a thermokarst lake (Lake...
Authors
Marcus Elvert, John W. Pohlman, Kevin W. Becker, Benjamin V. Gaglioti, Kai-Uwe Hinrichs, Matthew J. Wooller