Articles | Volume 16, issue 7
Atmos. Chem. Phys., 16, 4593–4604, 2016
https://doi.org/10.5194/acp-16-4593-2016
Atmos. Chem. Phys., 16, 4593–4604, 2016
https://doi.org/10.5194/acp-16-4593-2016

Research article 13 Apr 2016

Research article | 13 Apr 2016

Exploring atmospheric blocking with GPS radio occultation observations

Lukas Brunner1,2, Andrea K. Steiner1,2,3, Barbara Scherllin-Pirscher1,3, and Martin W. Jury1 Lukas Brunner et al.
  • 1Wegener Center for Climate and Global Change (WEGC), University of Graz, Graz, Austria
  • 2FWF-DK Climate Change, University of Graz, Graz, Austria
  • 3Institute for Geophysics, Astrophysics, and Meteorology, Institute of Physics, University of Graz, Graz, Austria

Abstract. Atmospheric blocking has been closely investigated in recent years due to its impact on weather and climate, such as heat waves, droughts, and flooding. We use, for the first time, satellite-based observations from Global Positioning System (GPS) radio occultation (RO) and explore their ability to resolve blocking in order to potentially open up new avenues complementing models and reanalyses. RO delivers globally available and vertically highly resolved profiles of atmospheric variables such as temperature and geopotential height (GPH). Applying a standard blocking detection algorithm, we find that RO data robustly capture blocking as demonstrated for two well-known blocking events over Russia in summer 2010 and over Greenland in late winter 2013. During blocking episodes, vertically resolved GPH gradients show a distinct anomalous behavior compared to climatological conditions up to 300 hPa and sometimes even further up into the tropopause. The accompanying increase in GPH of up to 300 m in the upper troposphere yields a pronounced tropopause height increase. Corresponding temperatures rise up to 10 K in the middle and lower troposphere. These results demonstrate the feasibility and potential of RO to detect and resolve blocking and in particular to explore the vertical structure of the atmosphere during blocking episodes. This new observation-based view is available globally at the same quality so that blocking in the Southern Hemisphere can also be studied with the same reliability as in the Northern Hemisphere.

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Short summary
Atmospheric blocking refers to persistent high-pressure systems which block the climatological flow at midlatitudes. We explore blocking with observations from GPS radio occultation (RO), a satellite-based remote-sensing system. Using two example cases, we find that RO data robustly capture blocking, highlighting the potential of RO observations to complement models and reanalysis as a basis for blocking research.
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