Search for: All records

This Arctic Observing Network (AON) project focuses on maintaining and expanding our long-term network of measurements of carbon, water, and energy exchange in terrestrial systems in Alaska. These exchanges help regulate the Arctic System and its feedbacks to global climate. Thus, extending long-term observations is a key science priority for the observing-change component of the Study of Environmental Arctic Change (SEARCH). Detecting and interpreting change in arctic carbon (C), water, and energy fluxes requires a continuous year-round record over multiple years. Recent data syntheses and modeling studies of Arctic Carbon balance suggest that tundra is either a carbon dioxide (CO2) sink, a source, or neutral (e.g., McGuire et al., 2009, McGuire et al., 2012) . This uncertainty arises mainly from a lack of data on winter CO2 flux and how tundra responds to recent warming. Because of harsh, remote environments and the lack of line power, long-term measurements of arctic CO2 fluxes over the full year are rare. We have been measuring year-round C, water, and energy fluxes for eleven years in two broadly representative flagship observatories with long-term histories of research, at Imnavait Creek near Toolik Lake, Alaska, and near Cherskiy, Siberia. Similar versions of these eddy covariance and biomet data are available from Ameriflux as sites US-ICx. https://ameriflux.lbl.gov/data/download-data/ Our three Imnavait Creek Alaska sites retained multiple names over the years. The following clarification is needed. The 'official' site name is followed by the technical station name (IC_xxxx), the positional name (Ridge), and the Ameriflux site name (US-ICx), and finally the site coordinates. Wet Sedge tundra (IC_1523, Fen, US-ICs) 68.6058 -149.3110 Tussock tundra (IC_1993, Tussock, US-ICt) 68.6063 -149.3041 Dry Heath tundra (IC_1991, Ridge, US-ICh) 68.6068 -149.2958 

This Arctic Observing Network (AON) project focuses on maintaining and expanding our long-term network of measurements of carbon, water, and energy exchange in terrestrial systems in Alaska. These exchanges help regulate the Arctic System and its feedbacks to global climate. Thus, extending long-term observations is a key science priority for the observing-change component of the Study of Environmental Arctic Change (SEARCH). Detecting and interpreting change in arctic carbon (C), water, and energy fluxes requires a continuous year-round record over multiple years. Recent data syntheses and modeling studies of Arctic Carbon balance suggest that tundra is either a carbon dioxide (CO2) sink, a source, or neutral (e.g., McGuire et al., 2009, McGuire et al., 2012) . This uncertainty arises mainly from a lack of data on winter CO2 flux and how tundra responds to recent warming. Because of harsh, remote environments and the lack of line power, long-term measurements of arctic CO2 fluxes over the full year are rare. We have been measuring year-round C, water, and energy fluxes for eleven years in two broadly representative flagship observatories with long-term histories of research, at Imnavait Creek near Toolik Lake, Alaska. To help interpret inter-annual variability we began making plot-based Normalized Difference Vegetation Index (NDVI) measurements three times a summer at our Imnavait Creek sites. 

This Arctic Observing Network (AON) project focuses on maintaining and expanding our long-term network of measurements of carbon, water, and energy exchange in terrestrial systems in Alaska. These exchanges help regulate the Arctic System and its feedbacks to global climate. Thus, extending long-term observations is a key science priority for the observing-change component of the Study of Environmental Arctic Change (SEARCH). Detecting and interpreting change in arctic carbon (C), water, and energy fluxes requires a continuous year-round record over multiple years. Recent data syntheses and modeling studies of Arctic Carbon balance suggest that tundra is either a carbon dioxide (CO2) sink, a source, or neutral (e.g., McGuire et al., 2009, McGuire et al., 2012) . This uncertainty arises mainly from a lack of data on winter CO2 flux and how tundra responds to recent warming. Because of harsh, remote environments and the lack of line power, long-term measurements of arctic CO2 fluxes over the full year are rare. We have been measuring year-round C, water, and energy fluxes for eleven years in two broadly representative flagship observatories with long-term histories of research, at Imnavait Creek near Toolik Lake, Alaska, and near Cherskiy, Siberia. Similar versions of these eddy covariance and biomet data are available from Ameriflux as sites US-ICx. https://ameriflux.lbl.gov/data/download-data/ Our three Imnavait Creek Alaska sites retained multiple names over the years. The following clarification is needed. The 'official' site name is followed by the technical station name (IC_xxxx), the positional name (Ridge), and the Ameriflux site name (US-ICx), and finally the site coordinates. Wet Sedge tundra (IC_1523, Fen, US-ICs) 68.6058 -149.3110 Tussock tundra (IC_1993, Tussock, US-ICt) 68.6063 -149.3041 Dry Heath tundra (IC_1991, Ridge, US-ICh) 68.6068 -149.2958 

This is the AmeriFlux Management Project (AMP) created FLUXNET-1F version of the carbon flux data for the site US-ICh Imnavait Creek Watershed Heath Tundra. This is the FLUXNET version of the carbon flux data for the site US-ICh Imnavait Creek Watershed Heath Tundra produced by applying the standard ONEFlux (1F) software. Site Description - The Imnavait Creek Watershed Heath Tundra (Ridge Station) is located near Imnavait Creek in Alaska, north of the Brooks Range in the Kuparuk basin near Lake Toolik and the Toolik Field Station. The Kuparuk River has its headwaters in the Brooks Range and drains through northern Alaska into the Arctic Ocean. Within these headwaters lies the Imnavait basin at an average elevation of 930 m. Water tracks run down the hill in parallel zones with a spacing of approximately 10 m. The Ridge Station was deployed at the end of Summer 2007. 

This is the AmeriFlux Management Project (AMP) created FLUXNET-1F version of the carbon flux data for the site US-ICt Imnavait Creek Watershed Tussock Tundra. This is the FLUXNET version of the carbon flux data for the site US-ICt Imnavait Creek Watershed Tussock Tundra produced by applying the standard ONEFlux (1F) software. Site Description - The Imnavait Creek Watershed Tussock Tundra (Biocomplexity Station) is located near Imnavait Creek in Alaska, north of the Brooks Range in the Kuparuk basin near Lake Toolik and the Toolik Field Station. The Kuparuk River has its headwaters in the Brooks Range and drains through northern Alaska into the Arctic Ocean. Within these headwaters lies the Imnavait basin at an average elevation of 930 m. Water tracks run down the hill in parallel zones with a spacing of approximately 10 m. The Biocomplexity Station was deployed in 2004, and it has been in operation during the melt seasons ever since. 

This is the AmeriFlux Management Project (AMP) created FLUXNET-1F version of the carbon flux data for the site US-ICs Imnavait Creek Watershed Wet Sedge Tundra. This is the FLUXNET version of the carbon flux data for the site US-ICs Imnavait Creek Watershed Wet Sedge Tundra produced by applying the standard ONEFlux (1F) software. Site Description - The Imnavait Creek Watershed Wet Sedge Tundra (Fen Station) is located near Imnavait Creek in Alaska, north of the Brooks Range in the Kuparuk basin near Lake Toolik and the Toolik Field Station. The Kuparuk River has its headwaters in the Brooks Range and drains through northern Alaska into the Arctic Ocean. Within these headwaters lies the Imnavait basin at an average elevation of 930 m. Water tracks run down the hill in parallel zones with a spacing of approximately 10 m. The Fen Station was deployed at the end of Summer 2007. 

This Arctic Observing Network (AON) project focuses on maintaining and expanding our long-term network of measurements of carbon, water, and energy exchange in terrestrial systems in Alaska. These exchanges help regulate the Arctic System and its feedbacks to global climate. Thus, extending long-term observations is a key science priority for the observing-change component of the Study of Environmental Arctic Change (SEARCH). Detecting and interpreting change in arctic C, water, and energy fluxes requires a continuous year-round record over multiple years. Recent data syntheses and modeling studies of Arctic Carbon balance suggest that tundra is either a carbon dioxide (CO2) sink, a source, or neutral (e.g., McGuire et al., 2009, McGuire et al., 2012) . This uncertainty arises mainly from a lack of data on winter CO2 flux and how tundra responds to recent warming. Because of harsh, remote environments and the lack of line power, long-term measurements of arctic CO2 fluxes over the full year are rare. We have been measuring year-round C, water, and energy fluxes for eleven years in two broadly representative flagship observatories with long-term histories of research, at Imnavait Creek near Toolik Lake, Alaska, and near Cherskiy, Siberia. Similar versions of these eddy covariance and biomet data are available from Ameriflux as sites US-ICx. https://ameriflux.lbl.gov/data/download-data/ Our three Imnavait Creek Alaska sites retained multiple names over the years. The following clarification is needed. The 'official' site name is followed by the technical station name (IC_xxxx), the positional name (Ridge), and the Ameriflux site name (US-ICx), and finally the site coordinates. Wet Sedge tundra (IC_1523, Fen, US-ICs) 68.6058 -149.3110 Tussock tundra (IC_1993, Tussock, US-ICt) 68.6063 -149.3041 Dry Heath tundra (IC_1991, Ridge, US-ICh) 68.6068 -149.2958 

This Arctic Observing Network (AON) project focuses on maintaining and expanding our long-term network of measurements of carbon, water, and energy exchange in terrestrial systems in Alaska. These exchanges help regulate the Arctic System and its feedbacks to global climate. Thus, extending long-term observations is a key science priority for the observing-change component of the Study of Environmental Arctic Change (SEARCH). Detecting and interpreting change in arctic C, water, and energy fluxes requires a continuous year-round record over multiple years. Recent data syntheses and modeling studies of Arctic Carbon balance suggest that tundra is either a carbon dioxide (CO2) sink, a source, or neutral (e.g., McGuire et al., 2009, McGuire et al., 2012) . This uncertainty arises mainly from a lack of data on winter CO2 flux and how tundra responds to recent warming. Because of harsh, remote environments and the lack of line power, long-term measurements of arctic CO2 fluxes over the full year are rare. We have been measuring year-round C, water, and energy fluxes for eleven years in two broadly representative flagship observatories with long-term histories of research, at Imnavait Creek near Toolik Lake, Alaska, and near Cherskiy, Siberia. Similar versions of these eddy covariance and biomet data are available from Ameriflux as sites US-ICx. https://ameriflux.lbl.gov/data/download-data/ Our three Imnavait Creek Alaska sites retained multiple names over the years. The following clarification is needed. The 'official' site name is followed by the technical station name (IC_xxxx), the positional name (Ridge), and the Ameriflux site name (US-ICx), and finally the site coordinates. Wet Sedge tundra (IC_1523, Fen, US-ICs) 68.6058 -149.3110 Tussock tundra (IC_1993, Tussock, US-ICt) 68.6063 -149.3041 Dry Heath tundra (IC_1991, Ridge, US-ICh) 68.6068 -149.2958 

This Arctic Observing Network (AON) project focuses on maintaining and expanding our long-term network of measurements of carbon, water, and energy exchange in terrestrial systems in Alaska. These exchanges help regulate the Arctic System and its feedbacks to global climate. Thus, extending long-term observations is a key science priority for the observing-change component of the Study of Environmental Arctic Change (SEARCH). Detecting and interpreting change in arctic C, water, and energy fluxes requires a continuous year-round record over multiple years. Recent data syntheses and modeling studies of Arctic Carbon balance suggest that tundra is either a carbon dioxide (CO2) sink, a source, or neutral (e.g., McGuire et al., 2009, McGuire et al., 2012) . This uncertainty arises mainly from a lack of data on winter CO2 flux and how tundra responds to recent warming. Because of harsh, remote environments and the lack of line power, long-term measurements of arctic CO2 fluxes over the full year are rare. We have been measuring year-round C, water, and energy fluxes for eleven years in two broadly representative flagship observatories with long-term histories of research, at Imnavait Creek near Toolik Lake, Alaska, and near Cherskiy, Siberia. Similar versions of these eddy covariance and biomet data are available from Ameriflux as sites US-ICx. https://ameriflux.lbl.gov/data/download-data/ Our three Imnavait Creek Alaska sites retained multiple names over the years. The following clarification is needed. The 'official' site name is followed by the technical station name (IC_xxxx), the positional name (Ridge), and the Ameriflux site name (US-ICx), and finally the site coordinates. Wet Sedge tundra (IC_1523, Fen, US-ICs) 68.6058 -149.3110 Tussock tundra (IC_1993, Tussock, US-ICt) 68.6063 -149.3041 Dry Heath tundra (IC_1991, Ridge, US-ICh) 68.6068 -149.2958 

To understand patterns in CO2 partial pressure (PCO2) over time in wetlands’ surface water and porewater, we examined the relationship between PCO2 and land–atmosphere flux of CO2 at the ecosystem scale at 22 Northern Hemisphere wetland sites synthesized through an open call. Sites spanned 6 major wetland types (tidal, alpine, fen, bog, marsh, and prairie pothole/karst), 7 Köppen climates, and 16 different years. Ecosystem respiration (Reco) and gross primary production (GPP), components of vertical CO2 flux, were compared to PCO2, a component of lateral CO2 flux, to determine if photosynthetic rates and soil respiration consistently influence wetland surface and porewater CO2 concentrations across wetlands. Similar to drivers of primary productivity at the ecosystem scale, PCO2 was strongly positively correlated with air temperature (Tair) at most sites. Monthly average PCO2 tended to peak towards the middle of the year and was more strongly related to Reco than GPP. Our results suggest Reco may be related to biologically driven PCO2 in wetlands, but the relationship is site-specific and could be an artifact of differently timed seasonal cycles or other factors. Higher levels of discharge do not consistently alter the relationship between Reco and temperature normalized PCO2. This work synthesizes relevant data and identifies key knowledge gaps in drivers of wetland respiration.