Daytime formation of nitrous acid at a coastal remote site in Cyprus indicating a common ground source of atmospheric HONO and NO

Hannah Meusel, Uwe Kuhn, Andreas Reiffs, Chinmay Mallik, Hartwig Harder, Monica Martinez, Jan Schuladen, Birger Bohn, Uwe Parchatka, John N. Crowley, Horst Fischer, Laura Tomsche, Anna Novelli, Thorsten Hoffmann, Ruud H.H. Janssen, Oscar Hartogensis, Michael Pikridas, Mihalis Vrekoussis, Efstratios Bourtsoukidis, Bettina WeberJos Lelieveld, Jonathan Williams, Ulrich Pöschl, Yafang Cheng, Hang Su*

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

20 Citations (Scopus)

Abstract

Characterization of daytime sources of nitrous acid (HONO) is crucial to understand atmospheric oxidation and radical cycling in the planetary boundary layer. HONO and numerous other atmospheric trace constituents were measured on the Mediterranean island of Cyprus during the CYPHEX (Cyprus PHotochemical EXperiment) campaign in summer 2014. Average volume mixing ratios of HONO were 35 pptv (±25 pptv) with a HONO/NOx ratio of 0.33, which was considerably higher than reported for most other rural and urban regions. Diel profiles of HONO showed peak values in the late morning (60 ± 28 pptv around 09:00 local time) and persistently high mixing ratios during daytime (45 ± 18 pptv), indicating that the photolytic loss of HONO is compensated by a strong daytime source. Budget analyses revealed unidentified sources producing up to 3.4 × 106 molecules cm-3 s-1 of HONO and up to 2.0 × 107 molecules cm-3 s-1 NO. Under humid conditions (relative humidity 2 Combining double low line 0.72), suggesting a common source that may be attributable to emissions from microbial communities on soil surfaces.

Original languageEnglish
Pages (from-to)14475-14493
JournalAtmospheric Chemistry and Physics
Volume16
Issue number22
DOIs
Publication statusPublished - 2016

    Fingerprint

Cite this