A multi-year record of airborne CO<sub>2</sub> observations in the US Southern Great Plains
-
Published:2013-03-15
Issue:3
Volume:6
Page:751-763
-
ISSN:1867-8548
-
Container-title:Atmospheric Measurement Techniques
-
language:en
-
Short-container-title:Atmos. Meas. Tech.
Author:
Biraud S. C.ORCID, Torn M. S., Smith J. R., Sweeney C., Riley W. J.ORCID, Tans P. P.
Abstract
Abstract. We report on 10 yr of airborne measurements of atmospheric CO2 mole fraction from continuous and flask systems, collected between 2002 and 2012 over the Atmospheric Radiation Measurement Program Climate Research Facility in the US Southern Great Plains (SGP). These observations were designed to quantify trends and variability in atmospheric mole fraction of CO2 and other greenhouse gases with the precision and accuracy needed to evaluate ground-based and satellite-based column CO2 estimates, test forward and inverse models, and help with the interpretation of ground-based CO2 mole-fraction measurements. During flights, we measured CO2 and meteorological data continuously and collected flasks for a rich suite of additional gases: CO2, CO, CH4, N2O, 13CO2, carbonyl sulfide (COS), and trace hydrocarbon species. These measurements were collected approximately twice per week by small aircraft (Cessna 172 initially, then Cessna 206) on a series of horizontal legs ranging in altitude from 460 m to 5500 m a.m.s.l. Since the beginning of the program, more than 400 continuous CO2 vertical profiles have been collected (2007–2012), along with about 330 profiles from NOAA/ESRL 12-flask (2006–2012) and 284 from NOAA/ESRL 2-flask (2002–2006) packages for carbon cycle gases and isotopes. Averaged over the entire record, there were no systematic differences between the continuous and flask CO2 observations when they were sampling the same air, i.e., over the one-minute flask-sampling time. Using multiple technologies (a flask sampler and two continuous analyzers), we documented a mean difference of < 0.2 ppm between instruments. However, flask data were not equivalent in all regards; horizontal variability in CO2 mole fraction within the 5–10 min legs sometimes resulted in significant differences between flask and continuous measurement values for those legs, and the information contained in fine-scale variability about atmospheric transport was not captured by flask-based observations. The CO2 mole fraction trend at 3000 m a.m.s.l. was 1.91 ppm yr−1 between 2008 and 2010, very close to the concurrent trend at Mauna Loa of 1.95 ppm yr−1. The seasonal amplitude of CO2 mole fraction in the free troposphere (FT) was half that in the planetary boundary layer (PBL) (~ 15 ppm vs. ~ 30 ppm) and twice that at Mauna Loa (approximately 8 ppm). The CO2 horizontal variability was up to 10 ppm in the PBL and less than 1 ppm at the top of the vertical profiles in the FT.
Publisher
Copernicus GmbH
Subject
Atmospheric Science
Reference53 articles.
1. Abshire, J. B., Riris, H., Allan, G. R., Weaver, C. J., Mao, J. P., Sun, X., Hasselbrack, W. L., Kawa, S. R., and Biraud, S.: Pulsed airborne lidar measurements of atmospheric CO2 column absorption, Tellus B, 62, 770–783, 2010. 2. Ackerman, T. P., Genio, A. D. D., Ellingson, R. G., Ferrare, R. A., Klein, S. A., McFarquhar, G. M., Lamb, P. J., Long, C. N., and Verlinde, J.: Atmospheric radiation measurement program science plan: current status and future direcitons of the ARM science program, US Department of Energy, Office of Biological and Environmental Research, Washington, DC, 2004. 3. Bakwin, P. S., Tans, P. P., Hurst, D. F., and Zhao, C. L.: Measurements of carbon dioxide on very tall towers: results of the NOAA/CMDL program, Tellus B, 50, 401–415, 1998. 4. Billesbach, D. P., Fischer, M. L., Torn, M. S., and Berry, J. A.: A portable eddy covariance system for the measurement of ecosystem-atmosphere exchange of CO2, water vapor, and energy, J. Atmos. Ocean. Tech., 21, 639–650, 2004. 5. Carouge, C., Rayner, P. J., Peylin, P., Bousquet, P., Chevallier, F., and Ciais, P.: What can we learn from European continuous atmospheric CO2 measurements to quantify regional fluxes – Part 2: Sensitivity of flux accuracy to inverse setup, Atmos. Chem. Phys., 10, 3119–3129, https://doi.org/10.5194/acp-10-3119-2010, 2010.
Cited by
40 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献
|
|