Long-term total OH reactivity measurements in a boreal forest
| Autor: | Ville Vakkari, Arnaud P. Praplan, Ditte Taipale, Toni Tykkä, Putian Zhou, Michael Boy, Dean Chen, Heidi Hellén, Tuukka Petäjä |
|---|---|
| Přispěvatelé: | INAR Physics, Institute for Atmospheric and Earth System Research (INAR), Global Atmosphere-Earth surface feedbacks, 33371210 - Vakkari, Ville T. |
| Jazyk: | angličtina |
| Rok vydání: | 2019 |
| Předmět: |
Atmospheric Science
010504 meteorology & atmospheric sciences Chemical transport model RADICAL REACTIVITY AMBIENT AIR 010501 environmental sciences VOLATILE ORGANIC-COMPOUNDS Mass spectrometry 01 natural sciences lcsh:Chemistry chemistry.chemical_compound SULFURIC-ACID ATMOSPHERIC CHEMISTRY 1172 Environmental sciences 0105 earth and related environmental sciences CHEMICAL MECHANISM 4112 Forestry Taiga BOUNDARY-LAYER RAIN-FOREST 15. Life on land Data availability lcsh:QC1-999 Trace gas TROPOSPHERIC DEGRADATION chemistry lcsh:QD1-999 13. Climate action Environmental chemistry Hydroxyl radical Late afternoon NEW-MODEL lcsh:Physics |
| Zdroj: | Atmospheric Chemistry and Physics, Vol 19, Pp 14431-14453 (2019) |
| ISSN: | 1680-7324 1680-7316 |
| Popis: | Corrigendum: The legend in Fig. 6e has been mislabeled. The gray colorcorresponds to “Missing” and the other colors should havecorresponded to the same species as in Fig. 6f. The figure,which is also the key figure of the article, can be found belowwith the correct legend. Total hydroxyl radical (OH) reactivity measurements were conducted at the second Station for Measuring Ecosystem-Atmosphere Relations (SMEAR II), a boreal forest site located in Hyytiala, Finland, from April to July 2016. The measured values were compared with OH reactivity calculated from a combination of data from the routine trace gas measurements (station mast) as well as online and offline analysis with a gas chromatographer coupled to a mass spectrometer (GC-MS) and offline liquid chromatography. Up to 104 compounds, mostly volatile organic compounds (VOCs) and oxidized VOCs, but also inorganic compounds, were included in the analysis, even though the data availability for each compound varied with time. The monthly averaged experimental total OH reactivity was found to be higher in April and May (ca. 20 s(-1)) than in June and July (7.6 and 15.4 s(-1), respectively). The measured values varied much more in spring with high reactivity peaks in late afternoon, with values higher than in the summer, in particular when the soil was thawing. Total OH reactivity values generally followed the pattern of mixing ratios due to change of the boundary layer height. The missing reactivity fraction (defined as the difference between measured and calculated OH reactivity) was found to be high. Several reasons that can explain the missing reactivity are discussed in detail such as (1) missing measurements due to technical issues, (2) not measuring oxidation compounds of detected biogenic VOCs, and (3) missing important reactive compounds or classes of compounds with the available measurements. In order to test the second hypothesis, a one-dimensional chemical transport model (SOSAA) has been used to estimate the amount of unmeasured oxidation products and their expected contribution to the reactivity for three different short periods in April, May, and July. However, only a small fraction ( |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|