Unexpected seasonality in quantity and composition of Amazon rainforest air reactivity
The hydroxyl radical (OH) removes most atmospheric pollutants from air. The loss frequency of OH radicals due to the combined effect of all gas-phase OH reactive species is a measureable quantity termed total OH reactivity. Here we present total OH reactivity observations in pristine Amazon rainfore...
| Authors: | , , , , , , |
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| Format: | article |
| Status: | Published version |
| Publication Date: | 2016 |
| Country: | España |
| Institution: | Consejo Superior de Investigaciones Científicas (CSIC) |
| Repository: | DIGITAL.CSIC. Repositorio Institucional del CSIC |
| OAI Identifier: | oai:digital.csic.es:10261/412829 |
| Online Access: | http://hdl.handle.net/10261/412829 https://api.elsevier.com/content/abstract/scopus_id/84955460116 |
| Access Level: | Open access |
| Keyword: | The hydroxyl radical (OH) Amazonian rainforest Pollutants http://metadata.un.org/sdg/9 http://metadata.un.org/sdg/7 http://metadata.un.org/sdg/11 http://metadata.un.org/sdg/12 http://metadata.un.org/sdg/3 Ensure healthy lives and promote well-being for all at all ages Ensure access to affordable, reliable, sustainable and modern energy for all Build resilient infrastructure, promote inclusive and sustainable industrialization and foster innovation Make cities and human settlements inclusive, safe, resilient and sustainable Ensure sustainable consumption and production patterns |
| Summary: | The hydroxyl radical (OH) removes most atmospheric pollutants from air. The loss frequency of OH radicals due to the combined effect of all gas-phase OH reactive species is a measureable quantity termed total OH reactivity. Here we present total OH reactivity observations in pristine Amazon rainforest air, as a function of season, time-of-day and height (0-80 m). Total OH reactivity is low during wet (10 s(-1)) and high during dry season (62 s(-1)). Comparison to individually measured trace gases reveals strong variation in unaccounted for OH reactivity, from 5 to 15% missing in wet-season afternoons to mostly unknown (average 79%) during dry season. During dry-season afternoons isoprene, considered the dominant reagent with OH in rainforests, only accounts for ∼20% of the total OH reactivity. Vertical profiles of OH reactivity are shaped by biogenic emissions, photochemistry and turbulent mixing. The rainforest floor was identified as a significant but poorly characterized source of OH reactivity. |
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