A~tropical West Pacific OH minimum and implications for stratospheric composition.

Rex, M., Wohltmann, I., Ridder, T., Lehmann, R., Rosenlof, K., Wennberg, P., Weisenstein, D., Notholt, J., Krüger, Kirstin, Mohr, Viktoria and Tegtmeier, Susann (2014) A~tropical West Pacific OH minimum and implications for stratospheric composition. Open Access Atmospheric Chemistry and Physics, 14 (9). pp. 4827-4841. DOI 10.5194/acp-14-4827-2014.

[thumbnail of acp-14-4827-2014.pdf]
acp-14-4827-2014.pdf - Published Version
Available under License Creative Commons Attribution.

Download (2MB) | Preview

Supplementary data:


Most of the short-lived biogenic and anthropogenic chemical species that are emitted into the atmosphere break down efficiently by reaction with OH and do not reach the stratosphere. Here we show the existence of a pronounced minimum in the tropospheric column of ozone over the West Pacific, the main source region for stratospheric air, and suggest a corresponding minimum of the tropospheric column of OH. This has the potential to amplify the impact of surface emissions on the stratospheric composition compared to the impact when assuming globally uniform OH conditions. Specifically, the role of emissions of biogenic halogenated species for the stratospheric halogen budget and the role of increasing emissions of SO2 in Southeast Asia or from minor volcanic eruptions for the increasing stratospheric aerosol loading need to be reassessed in light of these findings. This is also important since climate change will further modify OH abundances and emissions of halogenated species. Our study is based on ozone sonde measurements carried out during the TransBrom cruise with the RV Sonne roughly along 140-150 degrees E in October 2009 and corroborating ozone and OH measurements from satellites, aircraft campaigns and FTIR instruments. Model calculations with the GEOS-Chem Chemistry and Transport Model (CTM) and the ATLAS CTM are used to simulate the tropospheric OH distribution over the West Pacific and the transport pathways to the stratosphere. The potential effect of the OH minimum on species transported into the stratosphere is shown via modeling the transport and chemistry of CH2Br2 and SO2.

Document Type: Article
Funder compliance: info:eu-repo/grantAgreement/EC/FP7/226224
Additional Information: WOS:000336739700027
Research affiliation: OceanRep > GEOMAR > FB1 Ocean Circulation and Climate Dynamics > FB1-ME Maritime Meteorology
Refereed: Yes
Open Access Journal?: Yes
Publisher: Copernicus Publications (EGU)
Projects: SHIVA, StratoClim, TRANSBROM, Future Ocean
Date Deposited: 01 Jul 2014 10:01
Last Modified: 09 Jul 2019 12:27
URI: https://oceanrep.geomar.de/id/eprint/24999

Actions (login required)

View Item View Item