Data to support: Implications of snowpack reactive bromine production for Arctic ice core bromine preservation
Data files
Sep 28, 2023 version files 6.28 GB
Abstract
Snowpack emissions are recognized as an important source of gas-phase reactive bromine in the Arctic and are necessary to explain ozone depletion events in spring caused by the catalytic destruction of ozone by halogen radicals. Quantifying bromine emissions from snowpack is essential for interpretation of ice-core bromine. We present ice-core bromine records since the pre-industrial (1750 CE) from six Arctic locations and examine potential post-depositional loss of snowpack bromine using a global chemical transport model. Trend analysis of the ice-core records shows that only the high-latitude coastal Akademii Nauk ice core from the Russian Arctic preserves significant trends since pre-industrial times that are consistent with trends in sea ice extent and anthropogenic emissions from source regions. Model simulations suggest that recycling of reactive bromine on the snow skin layer (top 1mm) results in 9–17% loss of deposited bromine across all six ice-core locations. Reactive bromine production from below the snow skin layer and within the snow photic zone is potentially more important, but the magnitude of this source is uncertain. Model simulations suggest that the Akademii Nauk core is most likely to preserve an atmospheric signal compared to five Greenland ice cores due to its high latitude location combined with a relatively high snow accumulation rate. Understanding the sources and amount of photochemically reactive snow bromide in the snow photic zone throughout the sunlit period in the high Arctic is essential for interpreting ice-core bromine, and warrants further lab studies and field observations at inland locations.
README: Data to support "Implications of Snowpack Reactive Bromine Production for Arctic Ice Core Bromine Preservation"
https://doi.org/10.5061/dryad.3j9kd51r4
This data set contains modeling output to support the Article "Implications of Snowpack Reactive Bromine Production for Arctic Ice Core Bromine Preservation".
Description of the data and file structure
The dataset contains results from each of 4 GEOS-Chem model simulations: mToyota, SURF, DEEP and DEEP2008. Please refer to the article for detailed description of the simulation setup. Each model simulation contains 28 data files (all model outputs are monthly averaged values):
- HEMCO_diagnostics.YYYYMMDD0000.nc: Emission fluxes, 1 file for each month, 12 files in total
- dryflx.YYYYMMDD.nc : dry deposition fluxes, 1 file for every 3 months, 4 files in total
- 3 and 4. wetdcv.YYYYMMDD.nc and wetdls.YYYYMMDD.nc: wet deposition fluxes, readers need to add these two together for the total wet deposition flux. 1 of each file (wetdcv and wetdls) for every 3 months, 8 files in total
- conc.YYYYMMDD.nc: concentration files, 1 file for every 3 months, 4 files in total
Sharing/Access information
GEOS-Chem is open software and available on https://doi.org/10.5281/zenodo.5047976. We used the version 11-02d.
Code/Software
Example python code (in jupyter notebook) to generate figures presented in the Article is also available:
SnowBrPaper_Fig.ModelResults.ipynb