Reactive Halogen Studies by Long-term MAX-DOAS Observations at Alert, Nunavut
Abstract
During sudden ozone and mercury depletion events in the polar boundary layer (BL) after sunrise, bromine oxide radicals (BrO) play a key role in catalytic ozone destruction cycles. Concentrations of BrO and several other species (e.g. IO, NO2) in the BL including vertical profile information can be obtained using ground-based Multi Axis Differential Optical Absorption Spectroscopy (MAX-DOAS). Previous studies were focussed on the chemical changes during and shortly after polar sunrise. In February 2003 a new fully automated Mini-MAX-DOAS system was set-up at Alert, Nunavut, Canada (82.5oN, 62.5oW) to perform the first long-term studies of reactive halogen chemistry (particularly BrO and IO) at this high Arctic location. Compared to satellite-based measurements which are available on a daily basis throughout the year, ground-based observations have a much higher temporal and spatial resolution at a specific location which is necessary for chemical process studies in the boundary layer. The high sensitivity of ground-based MAX-DOAS allows studying small events during springtime and possible reactive halogen abundances during other times of the year. Results of several BrO events observed during polar spring 2003 as well as first data obtained during summer are presented and discussed here.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2003
- Bibcode:
- 2003AGUFM.A11F0050H
- Keywords:
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- 0300 ATMOSPHERIC COMPOSITION AND STRUCTURE;
- 0365 Troposphere: composition and chemistry;
- 0394 Instruments and techniques