Roland Rohloff

AS Atmospheric Sciences

The 2019 Outstanding Student Poster and PICO (OSPP) Award is awarded to Roland Rohloff for the poster/PICO entitled:

Measurements of HO_x in the outflow of convective systems (Rohloff, R.; Marno, D.; Martinez, M.; Dienhart, D.; Tadic, I.; Fischer, H.; Lelieveld, J.; Harder, H.)

Click here to download the poster/PICO file.

Roland Rohloff is a PhD-student at the Max Planck Institute for Chemistry in Mainz. He is working in the atmospheric radical measurement group led by Hartwig Harder. The focus of his work is on the self-cleaning capacity of the atmosphere in convective outflow during the West-African-monsoon 2018. The airborne measurements were carried out as part of the CAFÉ-Africa campaign (Chemistry of the Atmosphere – Field Experiment). The hydroxyl (OH) radical is one of the most important oxidants in the troposphere during daytime. OH-radicals are generated by photolysis. They oxidize various pollutants (e.g. VOCs, CO) and therefore work as self-cleaning agent of the atmosphere. The reactions can result either in the loss of the radical, or in the formation of a new radical (e.g. RO₂, HO₂). Following, HO₂ can react with Ozone and NO to form and OH radical, thus “recycling” them. They are in fast equilibrium through this process and grouped together as HO_x. In order to gain a better understanding of atmospheric oxidation processes it is important to see how often an OH-radical can undergo this recycling process before it is removed. The poster presented at EGU 2019 showed elevated OH at the cloud deck as well as elevated OH in the convective outflow of electrified systems.