Improvement of stratospheric balloon GPS positioning and the impact on gravity wave parameter estimation for the Concordiasi campaign in Antarctica

TitleImprovement of stratospheric balloon GPS positioning and the impact on gravity wave parameter estimation for the Concordiasi campaign in Antarctica
Publication TypeJournal Article
Year of Publication2016
AuthorsZhang W.X, Haase JS, Hertzog A., Lou Y.D, Vincent R.
JournalJournal of Geophysical Research-Atmospheres
Volume121
Pagination9977-9997
Date Published2016/09
Type of ArticleArticle
ISBN Number2169-897X
Accession NumberWOS:000384823000028
Keywordsclimate; Concordiasi; dynamics; equatorial lower stratosphere; flights; gcm; GPS; GW; intermittency; models; momentum flux; mountain waves; phase; SPB; speeds
Abstract

Gravity waves (GWs) play an important role in transferring energy and momentum from the troposphere to the middle atmosphere. However, shorter-scale GWs are generally not explicitly resolved in general circulation models but need to be parameterized instead. Super pressure balloons provide direct access to measure GW characteristics as a function of wave intrinsic frequency that are needed for these parameterizations. The 30s sampling rate of the GPS receivers carried on the balloons deployed in the 2010 Concordiasi campaign in the Antarctic is much higher compared to the previous campaigns and can cover the full range of the GW spectrum. Two among 19 balloons are also equipped with the dual-frequency GPS receivers initially developed for GPS radio occultation research in addition to the single-frequency receivers, which are expected to provide better positions for GW parameter estimations. Improvements of the positions are significant, from similar to 3-10m horizontal and similar to 5m vertical to similar to 0.1 and 0.2m, respectively, which makes it possible to resolve the Eulerian pressure independently of altitude for the intrinsic phase speed estimation. The lower position accuracy in the previous analysis of campaign results from the single-frequency GPS receiver was primarily due to a problem with the onboard clock that is not present in the new results. The impacts of the position improvements on the final GW parameters are highlighted, with larger difference in momentum flux for the shorter-scale GWs than for the longer scale GWs and significant difference in the distribution of the intrinsic phase speed.

DOI10.1002/2015jd024596
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