Thomas Holst
Forskare
Vertical distribution of sources and sinks of volatile organic compounds within a boreal forest canopy
Författare
Summary, in English
The ecosystem-atmosphere flux of biogenic volatile organic compounds (BVOCs) has important impacts on tropospheric oxidative capacity and the formation of secondary organic aerosols, influencing air quality and climate. Here we present within-canopy measurements of a set of dominant BVOCs in a managed spruce- and pine-dominated boreal forest located at the ICOS (Integrated Carbon Observation System) station Norunda in Sweden, collected using proton-transfer-reaction mass spectrometry (PTR-MS) during 2014-2016 and vertical emission profiles derived from these data. Ozone concentrations were simultaneously measured in conjunction with these PTR-MS measurements. The main BVOCs investigated with the PTR-MS were isoprene, monoterpenes, methanol, acetaldehyde, and acetone. The distribution of BVOC sources and sinks in the forest canopy was explored using Lagrangian dispersion matrix methods, in particular continuous near-field theory. The forest canopy was found to contribute ca. 86% to the total monoterpene emission in summertime, whereas the below-canopy and canopy emissions were comparable (ca. 42% and 58%, respectively) during the fall period. This result indicates that boreal forest litter and other below-canopy emitters are a principal source of total forest monoterpene emissions during the fall months. During night, our results for methanol, acetone, and acetaldehyde seasonally present strong sinks in the forest canopy, especially in the fall, likely due to the nighttime formation of dew on vegetation surfaces.
Avdelning/ar
- Institutionen för naturgeografi och ekosystemvetenskap
- BECC: Biodiversity and Ecosystem services in a Changing Climate
- LTH profilområde: Aerosoler
- Centrum för hälsosamma inomhusmiljöer, CHIE
- MERGE: ModElling the Regional and Global Earth system
- ICOS Sweden
- LU profilområde: Naturbaserade framtidslösningar
- Centrum för miljö- och klimatvetenskap (CEC)
Publiceringsår
2023-07-14
Språk
Engelska
Sidor
7839-7858
Publikation/Tidskrift/Serie
Atmospheric Chemistry and Physics
Volym
23
Issue
13
Dokumenttyp
Artikel i tidskrift
Förlag
Copernicus GmbH
Ämne
- Climate Research
Status
Published
Projekt
- Sesquiterpene emissions from boreal forest, and their interactions with climate and tropospheric chemistry
- FORMAS: Towards full understanding of managed boreal forests as part of climate system: Role of biogenic volatile organic compounds
ISBN/ISSN/Övrigt
- ISSN: 1680-7324