Ozone uptake by an evergreen forest canopy: temporal variation and possible mechanisms

Research output: Contribution to journalJournal articleResearchpeer-review

Patterns of ozone concentration ([O(3)]), O(3) deposition velocity (v(d)) and O(3) flux (F(c)) over an evergreen forest canopy are shown in relation to measuring method, physiological activity of the trees, and time of year. The gradient and eddy correlation methods were compared and showed similar diel v(d) patterns. Daytime F(c) was correlated with CO(2) and water vapour fluxes, while no correlation between [O(3)] in the range 10-70 ppb (nl l(-1)) and F(c) was seen in this study. F(c) was primarily driven by stomatal conductance, reactions with surfaces, particles and gases, and not by [O(3)]. On a monthly basis, [O(3)] was always highest in the afternoon while v(d) was typically higher in the morning, resulting in an equal F(c) over the day. Night-time F(c) was more than half of the daytime O(3) flux. The data reveal the importance of emissions of nitric oxide and terpenes as O(3) removal factors in evergreen forest dominated by Norway spruce.
Original languageEnglish
JournalEnvironmental Pollution
Issue number3
Pages (from-to)423-429
Number of pages6
Publication statusPublished - 2000

Bibliographical note

Keywords: Ozone flux; Ozone deposition; Terpenes; Volatile organic compounds; Gradient and eddy correlation method

ID: 182239