Prediction of Springtime Tropospheric Arctic Reactive Bromine Levels From Environmental Variables
Abstract
Reactive bromine is produced by photochemistry on frozen saline surfaces during the Arctic spring. The chemical mechanisms driving release of reactive bromine into the Arctic environment are nonlinear in nature. However, the fate of the reactive bromine additionally depends on local meteorology and frozen surface landscape, which display more linear behavior. The O-Buoy project gathered Arctic Ocean observations of bromine monoxide (BrO) from 2011-2016. Two measurements of tropospheric reactive bromine were retrieved from MAX-DOAS spectra: the density of BrO in the lowest 2000 m (Column BrO), and the density of BrO in the lowest 200 m (Surface BrO). A detailed dataset containing both chemical and meteorological variables was produced by combining O-Buoy observations with MERRA-2 meteorological reanalysis products. Principal components analysis was used to identify the most important relationships within this dataset. These relationships were used to construct two independent linear models; one to predict surface BrO and one to predict column BrO. The models show consistent correlation to observed BrO, with R2= 0.26 for column BrO and R2= 0.25 for surface BrO. The relationships used to predict column BrO find that low pressure, low temperatures, and high aerosol extinction are related to high column BrO. The relationships used to predict surface BrO find that low temperatures and high extinction are related to high surface BrO, but no significant relation to pressure is noted. The results from these linear models will aid in understanding the weather patterns driving variation in tropospheric Arctic reactive bromine levels.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2018
- Bibcode:
- 2018AGUFM.V43E0160S
- Keywords:
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- 0365 Troposphere: composition and chemistry;
- ATMOSPHERIC COMPOSITION AND STRUCTUREDE: 1030 Geochemical cycles;
- GEOCHEMISTRYDE: 3613 Subduction zone processes;
- MINERALOGY AND PETROLOGYDE: 8430 Volcanic gases;
- VOLCANOLOGY