Speaker
Dr
Apostolos Voulgarakis
(NASA Goddard Institute for Space Studies at Columbia University, New York, USA)
Description
Climate projections suggest that a complete Arctic sea-ice retreat is likely in the future during summer. Less ice will
cause less light reflection and slower tropospheric photolysis. We use a tropospheric chemistry model to examine
how oxidation may differ over an ice-free Arctic. We find that late-summer OH concentrations can decrease by
30–60% at polar latitudes, while effects on local ozone and global oxidant abundances are small. Ozone changes
become larger in the more extreme case where sea-ice is also removed in spring and early summer. In this case,
we find large spring ozone increases (up to 50–60%) over the Arctic, and even over inhabited high latitude regions
(up to 20%), due mainly to a reduction in the impact of bromine chemistry, caused by the sea-ice retreat. Annual
mean ozone also increases in the run with the summer/spring sea-ice removal, but not in the simulation including
only late-summer sea-ice removal.
Please list some keywords
sea-ice retreat, photolysis rates, hydroxyl radical, bromine, tropospheric ozone
Author
Dr
Apostolos Voulgarakis
(NASA Goddard Institute for Space Studies at Columbia University, New York, USA)
