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Impact of the South Asian monsoon outflow on atmospheric hydroperoxides in the upper troposphere

Hottmann, B.; Hafermann, S.; Tomsche, L.; Marno, D.; Martinez, M.; Harder, H.; Pozzer, A.; Neumaier, Marco; Zahn, Andreas; Bohn, B.; Stratmann, G.; Ziereis, H.; Lelieveld, J.; Fischer, H.

Abstract:
During the OMO (Oxidation Mechanism Observation) mission, trace gas measurements were performed on board the HALO (High Altitude Long Range) research aircraft in summer 2015 in order to investigate the outflow of the South Asian summer monsoon and its influence on the composition of the Asian monsoon anticyclone (AMA) in the upper troposphere over the eastern Mediterranean and the Arabian Peninsula. This study focuses on in situ observations of hydrogen peroxide (H$_{2}$O$_{2}$$^{obs}$) and organic hydroperoxides (ROOH$^{obs}$) as well as their precursors and loss processes. Observations are compared to photostationary-state (PSS) calculations of H$_{2}$O$_{2}$$^{PSS}$ and extended by a separation of ROOH$^{obs}$ into methyl hydroperoxide (MHP$^{PSS}$) and inferred unidentified hydroperoxide (UHP$^{PSS}$) mixing ratios using PSS calculations. Measurements are also contrasted to simulations with the general circulation ECHAM–MESSy for Atmospheric Chemistry (EMAC) model. We observed enhanced mixing ratios of H$_{2}$O$_{2}$$^{obs}$ (45 %), MHP$^{PSS}$ (9 %), and UHPPSS (136 %) in the AMA relative to the northern hemispheric background. Highest concentrations for H$_{2}$O$_{2}$$^{obs}$ and MHP$^{PSS}$ of 211 and 152 ppb$_{V}$, respectively, were found in the tropics outside the AMA, while for UHP$^{PSS}$, with 208 ppt$_{V}$, highest concentrations were found within the AMA. ... mehr


Verlagsausgabe §
DOI: 10.5445/IR/1000126637
Veröffentlicht am 24.11.2020
Originalveröffentlichung
DOI: 10.5194/acp-20-12655-2020
Scopus
Zitationen: 1
Web of Science
Zitationen: 1
Dimensions
Zitationen: 2
Cover der Publikation
Zugehörige Institution(en) am KIT Institut für Meteorologie und Klimaforschung - Atmosphärische Spurenstoffe und Fernerkundung (IMK-ASF)
KIT-Zentrum Klima und Umwelt (ZKU)
Publikationstyp Zeitschriftenaufsatz
Publikationsjahr 2020
Sprache Englisch
Identifikator ISSN: 1680-7316, 1680-7324
KITopen-ID: 1000126637
Erschienen in Atmospheric chemistry and physics
Verlag EGU
Band 20
Heft 21
Seiten 12655-12673
Nachgewiesen in Dimensions
Scopus
Web of Science
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