Acta Geophysica

, Volume 57, Issue 4, pp 904–922 | Cite as

A preliminary investigation of boundary layer effects on daytime atmospheric CO2 concentrations at a mountaintop location in the Rocky Mountains

  • Stephan F.J. De Wekker
  • Alex Ameen
  • Guan Song
  • Britton B. Stephens
  • Anna G. Hallar
  • Ian B. McCubbin


Observations of CO2 concentration at a mountaintop in the Colorado Rockies in summer show a large diurnal variability with minimum CO2 concentrations found between 10:00 and 18:00 MST. Simulations are performed with a mesoscale model to examine the effects of atmospheric structure and large-scale flows on the diurnal variability. In the simulations initialized without large-scale winds, the CO2 minimum occurs earlier compared to the observations. Upslope flows play an important role in the presence of this early (pre-noon) minimum while the timing and magnitude of the minimum depend only weakly on the temperature structure. An increase in large-scale flow has a noticeable impact on the diurnal variability with a more gradual decrease in daytime CO2 concentration, similar to summer-averaged observations. From the idealized simulations and a case study, it is concluded that multi-scale flows and their interactions have a large influence on the observed diurnal variability.

Key words

mesoscale circulations atmospheric boundary layer complex terrain CO2 concentration mountaintop observatory 


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Copyright information

© © Versita Warsaw and Springer-Verlag Berlin Heidelberg 2009

Authors and Affiliations

  • Stephan F.J. De Wekker
    • 1
  • Alex Ameen
    • 1
  • Guan Song
    • 1
  • Britton B. Stephens
    • 2
  • Anna G. Hallar
    • 3
  • Ian B. McCubbin
    • 3
  1. 1.Department of Environmental SciencesUniversity of VirginiaCharlottesvilleUSA
  2. 2.National Center for Atmospheric ResearchBoulderUSA
  3. 3.Storm Peak LaboratoryDesert Research InstituteSteamboat SpringsUSA

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