Abstract
Gas-phase formaldehyde (HCHO) was measured at a mixed deciduous/coniferous forest site as a part of the PROPHET 1998 summer field intensive. For the measurement period of July 11 through August 20, 1998, formaldehyde mixing ratios ranged from 0.5 to 12 ppb at a height ∼10 m above the forest canopy, with the highest concentrations observed in southeasterly air masses. Concentrations varied on average from a mid-afternoon maximum influenced by photochemical production of 4.0 ppb, to a late night minimum of 2.2 ppb, probably resulting from dry depositional loss. An analysis of local HCHO sources revealed that isoprene was the most important of the measured formaldehyde precursors, contributing, on average, 82% of the calculated midday HCHO production rate. We calculate that the nighttime HCHO dry deposition velocity is 2.6 times that of ozone, or approximately 0.65 cm/s. In the daytime, photolysis, dry deposition, and reaction with hydroxyl radical (OH) are roughly equally important as loss processes. Explicit calculations of HCHO chemical behavior highlighted the probable importance of transport and surface deposition to understanding the diel behavior of formaldehyde.
| Original language | English (US) |
|---|---|
| Article number | 2000JD900761 |
| Pages (from-to) | 24387-24405 |
| Number of pages | 19 |
| Journal | Journal of Geophysical Research Atmospheres |
| Volume | 106 |
| Issue number | D20 |
| DOIs | |
| State | Published - Oct 27 2001 |
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All Science Journal Classification (ASJC) codes
- Geophysics
- Forestry
- Oceanography
- Aquatic Science
- Ecology
- Water Science and Technology
- Soil Science
- Geochemistry and Petrology
- Earth-Surface Processes
- Atmospheric Science
- Earth and Planetary Sciences (miscellaneous)
- Space and Planetary Science
- Palaeontology
Cite this
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A study of formaldehyde chemistry above a forest canopy. / Sumner, Ann Louise; Shepson, Paul B.; Couch, Tara L.; Thornberry, Troy; Carroll, Mary Anne; Sillman, Sandy; Pippin, Margaret; Bertman, Steven; Tan, David; Faloona, Ian; Brune, William; Young, Valerie; Cooper, Owen; Moody, Jennie; Stockwell, William.
In: Journal of Geophysical Research Atmospheres, Vol. 106, No. D20, 2000JD900761, 27.10.2001, p. 24387-24405.Research output: Contribution to journal › Article
TY - JOUR
T1 - A study of formaldehyde chemistry above a forest canopy
AU - Sumner, Ann Louise
AU - Shepson, Paul B.
AU - Couch, Tara L.
AU - Thornberry, Troy
AU - Carroll, Mary Anne
AU - Sillman, Sandy
AU - Pippin, Margaret
AU - Bertman, Steven
AU - Tan, David
AU - Faloona, Ian
AU - Brune, William
AU - Young, Valerie
AU - Cooper, Owen
AU - Moody, Jennie
AU - Stockwell, William
PY - 2001/10/27
Y1 - 2001/10/27
N2 - Gas-phase formaldehyde (HCHO) was measured at a mixed deciduous/coniferous forest site as a part of the PROPHET 1998 summer field intensive. For the measurement period of July 11 through August 20, 1998, formaldehyde mixing ratios ranged from 0.5 to 12 ppb at a height ∼10 m above the forest canopy, with the highest concentrations observed in southeasterly air masses. Concentrations varied on average from a mid-afternoon maximum influenced by photochemical production of 4.0 ppb, to a late night minimum of 2.2 ppb, probably resulting from dry depositional loss. An analysis of local HCHO sources revealed that isoprene was the most important of the measured formaldehyde precursors, contributing, on average, 82% of the calculated midday HCHO production rate. We calculate that the nighttime HCHO dry deposition velocity is 2.6 times that of ozone, or approximately 0.65 cm/s. In the daytime, photolysis, dry deposition, and reaction with hydroxyl radical (OH) are roughly equally important as loss processes. Explicit calculations of HCHO chemical behavior highlighted the probable importance of transport and surface deposition to understanding the diel behavior of formaldehyde.
AB - Gas-phase formaldehyde (HCHO) was measured at a mixed deciduous/coniferous forest site as a part of the PROPHET 1998 summer field intensive. For the measurement period of July 11 through August 20, 1998, formaldehyde mixing ratios ranged from 0.5 to 12 ppb at a height ∼10 m above the forest canopy, with the highest concentrations observed in southeasterly air masses. Concentrations varied on average from a mid-afternoon maximum influenced by photochemical production of 4.0 ppb, to a late night minimum of 2.2 ppb, probably resulting from dry depositional loss. An analysis of local HCHO sources revealed that isoprene was the most important of the measured formaldehyde precursors, contributing, on average, 82% of the calculated midday HCHO production rate. We calculate that the nighttime HCHO dry deposition velocity is 2.6 times that of ozone, or approximately 0.65 cm/s. In the daytime, photolysis, dry deposition, and reaction with hydroxyl radical (OH) are roughly equally important as loss processes. Explicit calculations of HCHO chemical behavior highlighted the probable importance of transport and surface deposition to understanding the diel behavior of formaldehyde.
UR - http://www.scopus.com/inward/record.url?scp=85029208890&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85029208890&partnerID=8YFLogxK
U2 - 10.1029/2000JD900761
DO - 10.1029/2000JD900761
M3 - Article
AN - SCOPUS:85029208890
VL - 106
SP - 24387
EP - 24405
JO - Journal of Geophysical Research: Atmospheres
JF - Journal of Geophysical Research: Atmospheres
SN - 2169-897X
IS - D20
M1 - 2000JD900761
ER -