The role of open lead interactions in atmospheric ozone variability between Arctic coastal and inland sites

Abstract Boundary layer atmospheric ozone depletion events (ODEs) are commonly observed across polar sea ice regions following polar sunrise. During March-April 2005 in Alaska, the coastal site of Barrow and inland site of Atqasuk experienced ODEs (O3 < 10 nmol mol-1) concurrently for 31% of the...

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Bibliographic Details
Published in:Elementa: Science of the Anthropocene
Main Authors: Peter K. Peterson, Kerri A. Pratt, William R. Simpson, Son V. Nghiem, Lemuel X. Pérez Pérez, Eric J. Boone, Denis Pöhler, Johannes Zielcke, Stephan General, Paul B. Shepson, Udo Frieß, Ulrich Platt, Brian H. Stirm
Format: Article in Journal/Newspaper
Language:English
Published: BioOne 2016
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Online Access:https://doi.org/10.12952/journal.elementa.000109
https://doaj.org/article/de87636f69874db9b9cdc88c07d76043
Description
Summary:Abstract Boundary layer atmospheric ozone depletion events (ODEs) are commonly observed across polar sea ice regions following polar sunrise. During March-April 2005 in Alaska, the coastal site of Barrow and inland site of Atqasuk experienced ODEs (O3 < 10 nmol mol-1) concurrently for 31% of the observations, consistent with large spatial scale ozone depletion. However, 7% of the time ODEs were exclusively observed inland at Atqasuk. This phenomenon also occurred during one of nine flights during the BRomine, Ozone, and Mercury EXperiment (BROMEX), when atmospheric vertical profiles at both sites showed near-surface ozone depletion only at Atqasuk on 28 March 2012. Concurrent in-flight BrO measurements made using nadir scanning differential optical absorption spectroscopy (DOAS) showed the differences in ozone vertical profiles at these two sites could not be attributed to differences in locally occurring halogen chemistry. During both studies, backward air mass trajectories showed that the Barrow air masses observed had interacted with open sea ice leads, causing increased vertical mixing and recovery of ozone at Barrow and not Atqasuk, where the air masses only interacted with tundra and consolidated sea ice. These observations suggest that, while it is typical for coastal and inland sites to have similar ozone conditions, open leads may cause heterogeneity in the chemical composition of the springtime Arctic boundary layer over coastal and inland areas adjacent to sea ice regions.