#11 Topic: Arctic Halogens
Lecturer: Anne Blechschmidt
Date: Monday, May 3, 2021 10:00 – 11:00 a.m.

Halogens play an important role for the chemistry and composition of the Arctic troposphere. In polar spring, the so called ‘bromine explosion’, a chemical chain reaction rapidly releasing bromine into the atmosphere takes place. These events are linked to depletion of tropospheric ozone and conversion of elemental to reactive gaseous mercury, thereby impacting on the oxidizing capacity of the troposphere and harming the biosphere. The release of organohalogens by phytoplankton and dissolved organic matter from the ocean further modulates tropospheric composition, with iodine monoxide being involved in the formation of cloud condensation nuclei. In this lecture, an introduction into the topic is given, including driving processes, the link to meteorology and remote sensing observations.