Interannual variability of terpenoid emissions in an alpine city
<p>Terpenoid emissions above urban areas are a complex mix of biogenic and anthropogenic emission sources. In line with previous studies we found that summertime terpenoid fluxes in an alpine city were dominated by biogenic sources. Inter-seasonal emission measurements revealed consistency for...
| Main Authors: | , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2022-04-01
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| Series: | Atmospheric Chemistry and Physics |
| Online Access: | https://acp.copernicus.org/articles/22/5603/2022/acp-22-5603-2022.pdf |
| Summary: | <p>Terpenoid emissions above urban areas are a complex mix of
biogenic and anthropogenic emission sources. In line with previous studies
we found that summertime terpenoid fluxes in an alpine city were dominated
by biogenic sources. Inter-seasonal emission measurements revealed
consistency for monoterpenes and sesquiterpenes but a large difference in
isoprene between the summers of 2015 and 2018. Standardized emission potentials
for monoterpenes and sesquiterpenes were 0.12 nmol m<span class="inline-formula"><sup>−2</sup></span> s<span class="inline-formula"><sup>−1</sup></span> and <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M3" display="inline" overflow="scroll" dspmath="mathml"><mrow><mn mathvariant="normal">3.0</mn><mo>×</mo><msup><mn mathvariant="normal">10</mn><mrow><mo>-</mo><mn mathvariant="normal">3</mn></mrow></msup></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="51pt" height="14pt" class="svg-formula" dspmath="mathimg" md5hash="50091dda1ceb2bc1a163192c01b209d9"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="acp-22-5603-2022-ie00001.svg" width="51pt" height="14pt" src="acp-22-5603-2022-ie00001.png"/></svg:svg></span></span> nmol m<span class="inline-formula"><sup>−2</sup></span> s<span class="inline-formula"><sup>−1</sup></span> in 2015 and 0.11 nmol m<span class="inline-formula"><sup>−2</sup></span> s<span class="inline-formula"><sup>−1</sup></span>
and <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M8" display="inline" overflow="scroll" dspmath="mathml"><mrow><mn mathvariant="normal">3.4</mn><mo>×</mo><msup><mn mathvariant="normal">10</mn><mrow><mo>-</mo><mn mathvariant="normal">3</mn></mrow></msup></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="51pt" height="14pt" class="svg-formula" dspmath="mathimg" md5hash="784efb379cba2a3c376ef084599ddb66"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="acp-22-5603-2022-ie00002.svg" width="51pt" height="14pt" src="acp-22-5603-2022-ie00002.png"/></svg:svg></span></span> nmol m<span class="inline-formula"><sup>−2</sup></span> s<span class="inline-formula"><sup>−1</sup></span> in 2018, respectively. Observed
isoprene fluxes were almost 3 times higher in 2018 than in 2015. This
factor decreased to 2.3 after standardizing isoprene fluxes to 30 <span class="inline-formula"><sup>∘</sup></span>C air temperature and photosynthetic active radiation (PAR) to 1000 <span class="inline-formula">µ</span>mol m<span class="inline-formula"><sup>−2</sup></span> s<span class="inline-formula"><sup>−1</sup></span>. Based on emission model parameterizations, increased
leaf temperatures can explain some of these differences, but standardized
isoprene emission potentials remained higher in 2018 when a heat wave
persisted. These data suggest a higher variability of interannual isoprene
fluxes than for other terpenes. Potential reasons for the observed
differences such as emission parameterization, footprint changes, water
stress conditions, and tree trimming are investigated.</p> |
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| ISSN: | 1680-7316 1680-7324 |