Soil Air Permeability and Carbon Dioxide Flux Measurements from the Soil Surface

2008 ◽  
Vol 39 (9-10) ◽  
pp. 1406-1415 ◽  
Author(s):  
Osama K. Nusier ◽  
Laith M. Rousan
Keyword(s):  
Carbon Dioxide ◽  
Soil Surface ◽  
Carbon Dioxide Flux ◽  
Air Permeability ◽  
Soil Air ◽  
Flux Measurements

scholarly journals Dried, closed-path eddy covariance method for measuring carbon dioxide flux over sea ice

2018 ◽  
Vol 11 (11) ◽  
pp. 6075-6090 ◽  
Author(s):  
Brian J. Butterworth ◽  
Brent G. T. Else
Keyword(s):  
Carbon Dioxide ◽  
Sea Ice ◽  
Eddy Covariance ◽  
Co2 Flux ◽  
Carbon Dioxide Flux ◽  
The Arctic ◽  
Closed Path ◽  
Eddy Covariance Method ◽  
Open Path ◽  
Flux Measurements

Abstract. The Arctic marine environment plays an important role in the global carbon cycle. However, there remain large uncertainties in how sea ice affects air–sea fluxes of carbon dioxide (CO2), partially due to disagreement between the two main methods (enclosure and eddy covariance) for measuring CO2 flux (FCO2). The enclosure method has appeared to produce more credible FCO2 than eddy covariance (EC), but is not suited for collecting long-term, ecosystem-scale flux datasets in such remote regions. Here we describe the design and performance of an EC system to measure FCO2 over landfast sea ice that addresses the shortcomings of previous EC systems. The system was installed on a 10 m tower on Qikirtaarjuk Island – a small rock outcrop in Dease Strait located roughly 35 km west of Cambridge Bay, Nunavut, in the Canadian Arctic Archipelago. The system incorporates recent developments in the field of air–sea gas exchange by measuring atmospheric CO2 using a closed-path infrared gas analyzer (IRGA) with a dried sample airstream, thus avoiding the known water vapor issues associated with using open-path IRGAs in low-flux environments. A description of the methods and the results from 4 months of continuous flux measurements from May through August 2017 are presented, highlighting the winter to summer transition from ice cover to open water. We show that the dried, closed-path EC system greatly reduces the magnitude of measured FCO2 compared to simultaneous open-path EC measurements, and for the first time reconciles EC and enclosure flux measurements over sea ice. This novel EC installation is capable of operating year-round on solar and wind power, and therefore promises to deliver new insights into the magnitude of CO2 fluxes and their driving processes through the annual sea ice cycle.

Oxygen measurements in the root zone facilitated by TDR

2000 ◽  
Vol 80 (1) ◽  
pp. 33-41 ◽  
Author(s):  
G.C. Topp ◽  
B. Dow ◽  
M. Edwards ◽  
E. G. Gregorich ◽  
W. E. Curnoe ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Plant Growth ◽  
Crop Yields ◽  
Root Zone ◽  
Soil Surface ◽  
Carbon Dioxide Flux ◽  
No Till ◽  
Oxygen Measurement ◽  
Oxygen Measurements ◽  
Temperature Water

Deleterious soil structural conditions, as from compaction, can reduce plant growth and yields by reducing aeration and oxygen in the rooting environment. Using a double-membrane oxygen cathode in each of four corn plots, we measured soil oxygen concentrations in duplicate at depths of 5, 10, 20 and 30 cm during the growing season. In addition, temperature, water content and bulk density determinations allowed the monitoring of O2 concentration trends under no-till and conventional-till corn management. Carbon dioxide flux from the soil surface was measured weekly. Temporal patterns of O2 levels fluctuated in response to rainfall at all depths but much less so at 30-cm depth. At 30 cm the O2 concentration remained inadequate for optimum plant growth (<0.01 kg m−3) for over 2 mo after planting under no-till with poorly timed trafficking. Under conventional till and appropriately timed trafficking adequate aeration occurred more than a month earlier than under no-till. The CO2 output was generally lower by 10 to 30% in no-till than that in conventional till, indicating measurably lower levels of biological activity. The relative magnitudes of mid-season O2 concentrations and CO2 flux densities showed the same pattern as the crop yields for all tillage treatments. More analyses of seasonal O2 consumption patterns are required to determine if lack of O2 is a causal factor for the reduced crop yield. Key words: TDR, aeration, oxygen measurement, carbon dioxide, tillage, root zone

Bowen ratio and closed chamber carbon dioxide flux measurements over sagebrush steppe vegetation

2001 ◽  
Vol 108 (2) ◽  
pp. 153-161 ◽  
Author(s):  
Raymond F Angell ◽  
Tony Svejcar ◽  
Jon Bates ◽  
Nicanor Z Saliendra ◽  
Douglas A Johnson
Keyword(s):  
Carbon Dioxide ◽  
Bowen Ratio ◽  
Carbon Dioxide Flux ◽  
Sagebrush Steppe ◽  
Closed Chamber ◽  
Steppe Vegetation ◽  
Flux Measurements

scholarly journals Addressing a systematic bias in carbon dioxide flux measurements with the EC150 and the IRGASON open-path gas analyzers

2016 ◽  
Vol 228-229 ◽  
pp. 349-359 ◽  
Author(s):  
M. Helbig ◽  
K. Wischnewski ◽  
G.H. Gosselin ◽  
S.C. Biraud ◽  
I. Bogoev ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Carbon Dioxide Flux ◽  
Systematic Bias ◽  
Open Path ◽  
Flux Measurements

scholarly journals Dried, closed-path eddy covariance method for measuring carbon dioxide flux over sea ice

2018 ◽  
Author(s):  
Brian J. Butterworth ◽  
Brent G. T. Else
Keyword(s):  
Carbon Dioxide ◽  
Sea Ice ◽  
Eddy Covariance ◽  
Co2 Flux ◽  
Carbon Dioxide Flux ◽  
The Arctic ◽  
Closed Path ◽  
Eddy Covariance Method ◽  
Open Path ◽  
Flux Measurements

Abstract. The Arctic marine environment plays an important role in the global carbon cycle. However, there remain large uncertainties in how sea ice affects air–sea fluxes of carbon dioxide (CO2), partially due to disagreement between the two main methods (enclosure and eddy covariance) for measuring CO2 flux (FCO2). The enclosure method has appeared to produce more credible FCO2 than eddy covariance (EC), but is not suited for collecting long-term, ecosystem-scale flux datasets in such remote regions. Here we describe the design and performance of an EC system to measure FCO2 over landfast sea ice that addresses the shortcomings of previous EC systems. The system was installed on a 10-m tower on Qikirtaarjuk Island – a small rock outcrop in Dease Strait located roughly 35 km west of Cambridge Bay, Nunavut in the Canadian Arctic Archipelago. The system incorporates recent developments in the field of air–sea gas exchange by measuring atmospheric CO2 using a closed-path infrared gas analyzer (IRGA) with a dried sample airstream, thus avoiding the known water vapor issues associated with using open-path IRGAs in low-flux environments. A description of the methods and the results from four months of continuous flux measurements from May through August 2017 are presented, highlighting the winter to summer transition from ice cover to open water. We show that the dried, closed-path EC system greatly reduces the magnitude of measured FCO2 compared to simultaneous open-path EC measurements, and for the first time reconciles EC and enclosure flux measurements over sea ice. This novel EC installation is capable of operating year-round on solar/wind power, and therefore promises to deliver new insights into the magnitude of CO2 fluxes and their driving processes through the annual sea ice cycle.

EFFECT OF PREVIOUS CROP RESIDUE ON SOIL SURFACE CARBON DIOXIDE FLUX IN MAIZE

Soil Science ◽  
2007 ◽  
Vol 172 (8) ◽  
pp. 589-597 ◽  
Author(s):  
Brigid Amos ◽  
Hui Shen ◽  
Timothy J. Arkebauer ◽  
Daniel T. Walters
Keyword(s):  
Carbon Dioxide ◽  
Crop Residue ◽  
Soil Surface ◽  
Carbon Dioxide Flux ◽  
Surface Carbon ◽  
Previous Crop

scholarly journals Intercomparison of Nine Micrometeorological Stations during the BEAREX08 Field Campaign

2011 ◽  
Vol 28 (11) ◽  
pp. 1390-1406 ◽  
Author(s):  
Joseph G. Alfieri ◽  
William P. Kustas ◽  
John H. Prueger ◽  
Lawrence E. Hipps ◽  
José L. Chávez ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Measurement Uncertainty ◽  
Critical Role ◽  
Carbon Dioxide Flux ◽  
Sensible Heat ◽  
Environmental Processes ◽  
Uncertainty Estimates ◽  
Flux Measurements ◽  
Uncertainty Analyses ◽  
Using Data

Abstract Land–atmosphere interactions play a critical role in regulating numerous meteorological, hydrological, and environmental processes. Investigating these processes often requires multiple measurement sites representing a range of surface conditions. Before these measurements can be compared, however, it is imperative that the differences among the instrumentation systems are fully characterized. Using data collected as a part of the 2008 Bushland Evapotranspiration and Agricultural Remote Sensing Experiment (BEAREX08), measurements from nine collocated eddy covariance (EC) systems were compared with the twofold objective of 1) characterizing the interinstrument variation in the measurements, and 2) quantifying the measurement uncertainty associated with each system. Focusing on the three turbulent fluxes (heat, water vapor, and carbon dioxide), this study evaluated the measurement uncertainty using multiple techniques. The results of the analyses indicated that there could be substantial variability in the uncertainty estimates because of the advective conditions that characterized the study site during the afternoon and evening hours. However, when the analysis was limited to nonadvective, quasi-normal conditions, the response of the nine EC stations were remarkably similar. For the daytime period, both the method of Hollinger and Richardson and the method of Mann and Lenschow indicated that the uncertainty in the measurements of sensible heat, latent heat, and carbon dioxide flux were approximately 13 W m−2, 27 W m−2, and 0.10 mg m−2 s−1, respectively. Based on the results of this study, it is clear that advection can greatly increase the uncertainty associated with EC flux measurements. Since these conditions, as well as other phenomena that could impact the measurement uncertainty, are often intermittent, it may be beneficial to conduct uncertainty analyses on an ongoing basis.

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