Surface Wetness as an Unexpected Control on Forest Exchange of Volatile Organic Acids

Details

• Journal Title:
  Geophysical Research Letters
• Personal Author:
  Fulgham, S. R. ; Millet, D. B. ; Alwe, H. D. ; Goldstein, A. H. ; Schobesberger, S. ; Farmer, D. K.
• NOAA Program & Office:
  OAR (Oceanic and Atmospheric Research) ; CPO (Climate Program Office)
• Description:
  We report bidirectional exchange of volatile acids, including isocyanic and alkanoic acids, over a pine forest across multiple seasons. The exchange velocity of these acids is well correlated with dew point depression, suggesting an equilibrium-driven continuum of flux. Wetness on forest surfaces impacts the vertical exchange of gases, and we suggest that water films and droplets drive equilibrium partitioning, with acids being solvated in surface wetness and released through evaporation. Despite their volatility, these acids partition into neutral-to-alkaline aqueous films, consistent with reported dew pH. This relationship between exchange velocity and dew point depression holds for a wetter mixed forest, but not a very dry orchard. Dew point depression is an excellent indicator of acid fluxes so long as the canopy is occasionally wetted.
• Keywords:
  • Volatile organic acids
• Source:
  Geophysical Research Letters 47(15): e2020GL088745
• DOI:
  https://doi.org/10.1029/2020GL088745
• Document Type:
  Journal Article
• Funding:
  Grant no. NA14OAR4310141
• Rights Information:
  Other
• Compliance:
  Submitted
• Download URL:
  https://repository.library.noaa.gov/view/noaa/45531/noaa_45531_DS1.pdf
• File Type:
  [PDF - 1.57 MB]
• Collection(s):
  Office of Oceanic and Atmospheric Research (OAR)
• Main Document Checksum:
  urn:sha256:874358aa4c11da8b2bc549f2b8f66a00def2f2f20136c8e4e395bc20c32b0133