Abstract
Recently, the number and amount of biogenically
emitted volatile organic compounds (VOCs) has been discussed
in great detail. Depending on the ecosystem, the published
number varies between a dozen and several hundred
compounds. We present ecosystem exchange fluxes from
a mixed oak–hornbeam forest in the Po Valley, Italy. The
fluxes were measured by a proton transfer reaction-timeof-
flight (PTR-ToF) mass spectrometer and calculated using
the eddy covariance (EC) method. Detectable fluxes were
observed for up to 29 compounds, dominated by isoprene,
which comprised over 60% of the total upward flux (on a
molar basis). The daily average of the total VOC upward flux
was 10.4 nmolm2 s1. Methanol had the highest concentration
and accounted for the largest downward flux. Methanol
seemed to be deposited to dew, as the downward flux happened
in the early morning, right after the calculated surface
temperature came closest to the calculated dew point temperature.
We estimated that up to 30% of the upward flux of methyl
vinyl ketone (MVK) and methacrolein (MACR) originated
from atmospheric oxidation of isoprene. A comparison between
two methods for the flux detection (manual and automated)
was made. Their respective advantages and disadvantages
were discussed and the differences in their results
shown. Both provide comparable results.
Lingua originale | Inglese |
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pagine (da-a) | 7171-7194 |
Numero di pagine | 24 |
Rivista | Atmospheric Chemistry and Physics |
Volume | 2016 |
DOI | |
Stato di pubblicazione | Pubblicato - 2016 |
Keywords
- Bosco FOntana
- Eddy covariance fluxes
- VOC