AmeriFlux Publications from the Community

A Comparison Of Water And Carbon Dioxide Exchange At A Windy Alpine Tundra And Subalpine Forest Site Near Niwot Ridge, Colorado
Blanken, P. D., Williams, M. W., Burns, S. P., Monson, R. K., Knowles, J., Chowanski, K., Ackerman, T.

Eddy covariance measurements of the surface energy balance and carbon dioxide exchange above high-elevation (3,480 m above sea level) alpine tundra located near Niwot Ridge, Colorado, were compared to simultaneous measurements made over an adjacent subalpine forest over two summers and one winter, from June 9, 2007 to July 3, 2008. …

Journal: Biogeochemistry, Volume 95 (1): 61-76 (2009), ISBN . DOI: 10.1007/s10533-009-9325-9 Sites: US-NR1

A Comparison Of Water And Carbon Dioxide Exchange At A Windy Alpine Tundra And Subalpine Forest Site Near Niwot Ridge, Colorado
Blanken, P. D., Williams, M. W., Burns, S. P., Monson, R. K., Knowles, J. F., Chowanski, K., Ackerman, T.

Journal: Biogeochemistry, Volume 95 (1): 61-76 (2009), ISBN . DOI: 10.1007/s10533-009-9325-9 Sites: US-NR1, US-NR3, US-NR4

An Evaluation Of Calibration Techniques For In Situ Carbon Dioxide Measurements Using A Programmable Portable Trace-Gas Measuring System
Burns, S. P., Delany, A. C., Sun, J., Stephens, B. B., Oncley, S. P., Maclean, G. D., Semmer, S. R., Schröter, J., Ruppert, J.

The construction and deployment of a portable trace-gas measurement system (TGaMS) is described. The air-collection system (dubbed HYDRA) collects air samples from 18 different locations and was connected to either one or two LI-COR LI-7000 gas analyzers to measure CO2. An in situ “field calibration” method, that uses four calibration …

Journal: Journal Of Atmospheric And Oceanic Technology, Volume 26 (2): 291-316 (2009), ISBN . DOI: 10.1175/2008JTECHA1080.1 Sites: US-NR1, US-NR2

Biological And Physical Influences On The Carbon Isotope Content Of Co2 In A Subalpine Forest Snowpack, Niwot Ridge, Colorado
Bowling, D. R., Massman, W. J., Schaeffer, S. M., Burns, S. P., Monson, R. K., Williams, M. W.

Considerable research has recently been devoted to understanding biogeochemical processes under winter snow cover, leading to enhanced appreciation of the importance of many winter ecological processes. In this study, a comprehensive investigation of the stable carbon isotope composition (δ13C) of CO2 within a high-elevation subalpine …

Journal: Biogeochemistry, Volume 95 (1): 37-59 (2009), ISBN . DOI: 10.1007/s10533-008-9233-4 Sites: US-NR1

Partitioning Net Ecosystem Carbon Exchange And The Carbon Isotopic Disequilibrium In A Subalpine Forest
ZOBITZ, J. M., BURNS, S. P., REICHSTEIN, M., BOWLING, D. R.

We investigate the utility of an improved isotopic method to partition the net ecosystem exchange of CO2 (F) into net photosynthesis (FA) and nonfoliar respiration (FR). Measurements of F and the carbon isotopic content in air at a high‐elevation coniferous forest (the Niwot Ridge AmeriFlux site) were used to partition F into FA …

Journal: Global Change Biology, Volume 14 (8): 1785-1800 (2008), ISBN . DOI: 10.1111/j.1365-2486.2008.01609.x Sites: US-NR1

Canopy Structure And Atmospheric Flows In Relation To The δ13c Of Respired Co2 In A Subalpine Coniferous Forest
Schaeffer, S. M., Anderson, D. E., Burns, S. P., Monson, R. K., Sun, J., Bowling, D. R.

Stable isotopes provide insight into ecosystem carbon cycling, plant physiological processes, atmospheric boundary-layer dynamics, and are useful for the integration of processes over multiple scales. Of particular interest is the carbon isotope content (δ13C) of nocturnal ecosystem-respired CO2 (δR). Recent advances in technology …

Journal: Agricultural And Forest Meteorology, Volume 148 (4): 592-605 (2008), ISBN . DOI: 10.1016/j.agrformet.2007.11.003 Sites: US-NR1

The Contribution Of Advective Fluxes To Net Ecosystem Exchange In A High-Elevation, Subalpine Forest
Yi, C., Anderson, D. E., Turnipseed, A. A., Burns, S. P., Sparks, J. P., Stannard, D. I., Monson, R. K.

The eddy covariance technique, which is used in the determination of net ecosystem CO2 exchange (NEE), is subject to significant errors when advection that carries CO2 in the mean flow is ignored. We measured horizontal and vertical advective CO2 fluxes at the Niwot Ridge AmeriFlux site (Colorado, USA) using a measurement approach …

Journal: Ecological Applications, Volume 18 (6): 1379-1390 (2008), ISBN . DOI: 10.1890/06-0908.1 Sites: US-NR1

Co2 Transport Over Complex Terrain
Sun, J., Burns, S. P., Delany, A. C., Oncley, S. P., Turnipseed, A. A., Stephens, B. B., Lenschow, D. H., LeMone, M. A., Monson, R. K., Anderson, D. E.

CO2 transport processes relevant for estimating net ecosystem exchange (NEE) at the Niwot Ridge AmeriFlux site in the front range of the Rocky Mountains, Colorado, USA, were investigated during a pilot experiment. We found that cold, moist, and CO2-rich air was transported downslope at night and upslope in the early morning at this …

Journal: Agricultural And Forest Meteorology, Volume 145 (1-2): 1-21 (2007), ISBN . DOI: 10.1016/j.agrformet.2007.02.007 Sites: US-NR1

Partitioning Net Ecosystem Exchange Of Co2: A Comparison Of A Bayesian/Isotope Approach To Environmental Regression Methods
Zobitz, J. M., Burns, S. P., Ogée, J., Reichstein, M., Bowling, D. R.

Separation of the net ecosystem exchange of CO2 (F) into its component fluxes of net photosynthesis (FA) and nonfoliar respiration (FR) is important in understanding the physical and environmental controls on these fluxes, and how these fluxes may respond to environmental change. In this paper, we evaluate a partitioning method based …

Journal: Journal Of Geophysical Research: Biogeosciences, Volume 112 (G3): n/a-n/a (2007), ISBN . DOI: 10.1029/2006JG000282 Sites: US-NR1

Model-Data Synthesis Of Diurnal And Seasonal CO2 Fluxes At Niwot Ridge, Colorado
Sacks, W. J., Schimel, D. S., Monson, R. K., Braswell, B. H.

Eddy covariance records hold great promise for understanding the processes controlling the net ecosystem exchange of CO₂ (NEE). However, NEE is the small difference …

Journal: Global Change Biology, Volume 12 (2): 240-259 (2006), ISBN . DOI: 10.1111/j.1365-2486.2005.01059.x Sites: US-NR1