Pan-Arctic surface ozone: modelling vs. measurements
Within the framework of the International Arctic Systems for Observing the Atmosphere (IASOA), we report a modelling-based study on surface ozone across the Arctic. We use surface ozone from six sites – Summit (Greenland), Pallas (Finland), Barrow (USA), Alert (Canada), Tiksi (Russia), and Villum Re...
Published in: | Atmospheric Chemistry and Physics |
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Main Authors: | , , , , , , , , , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Copernicus Publications
2020
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Subjects: | |
Online Access: | https://doi.org/10.5194/acp-20-15937-2020 https://noa.gwlb.de/receive/cop_mods_00055006 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00054657/acp-20-15937-2020.pdf https://acp.copernicus.org/articles/20/15937/2020/acp-20-15937-2020.pdf |
Summary: | Within the framework of the International Arctic Systems for Observing the Atmosphere (IASOA), we report a modelling-based study on surface ozone across the Arctic. We use surface ozone from six sites – Summit (Greenland), Pallas (Finland), Barrow (USA), Alert (Canada), Tiksi (Russia), and Villum Research Station (VRS) at Station Nord (North Greenland, Danish realm) – and ozone-sonde data from three Canadian sites: Resolute, Eureka, and Alert. Two global chemistry models – a global chemistry transport model (parallelised-Tropospheric Offline Model of Chemistry and Transport, p-TOMCAT) and a global chemistry climate model (United Kingdom Chemistry and Aerosol, UKCA) – are used for model data comparisons. Remotely sensed data of BrO from the GOME-2 satellite instrument and ground-based multi-axis differential optical absorption spectroscopy (MAX-DOAS) at Eureka, Canada, are used for model validation. The observed climatology data show that spring surface ozone at coastal sites is heavily depleted, making ozone seasonality at Arctic coastal sites distinctly different from that at inland sites. Model simulations show that surface ozone can be greatly reduced by bromine chemistry. In April, bromine chemistry can cause a net ozone loss (monthly mean) of 10–20 ppbv, with almost half attributable to open-ocean-sourced bromine and the rest to sea-ice-sourced bromine. However, the open-ocean-sourced bromine, via sea spray bromide depletion, cannot by itself produce ozone depletion events (ODEs; defined as ozone volume mixing ratios, VMRs, < 10 ppbv). In contrast, sea-ice-sourced bromine, via sea salt aerosol (SSA) production from blowing snow, can produce ODEs even without bromine from sea spray, highlighting the importance of sea ice surface in polar boundary layer chemistry. Modelled total inorganic bromine (BrY) over the Arctic sea ice is sensitive to model configuration; e.g. under the same bromine loading, BrY in the Arctic spring boundary layer in the p-TOMCAT control run (i.e. with all bromine emissions) can be ... |
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