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

• Published in: Journal of Geophysical Research: Atmospheres
• Main Authors: Zhang, Weixing, Haase, Jennifer S., Hertzog, Albert, Lou, Yidong, Vincent, Robert
• Other Authors: Laboratoire de Météorologie Dynamique (UMR 8539) (LMD), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-École des Ponts ParisTech (ENPC)-Centre National de la Recherche Scientifique (CNRS)-Département des Géosciences - ENS Paris, École normale supérieure - Paris (ENS-PSL), Université Paris Sciences et Lettres (PSL)-Université Paris Sciences et Lettres (PSL)-École normale supérieure - Paris (ENS-PSL), Université Paris Sciences et Lettres (PSL)-Université Paris Sciences et Lettres (PSL)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2016
• Subjects: SPB; GPS; GW; Concordiasi; GCM; [SDU]Sciences of the Universe [physics]; Antarctic; The Antarctic; Antarc*; Antarctica
• Online Access: https://insu.hal.science/insu-03727102; https://insu.hal.science/insu-03727102/document; https://insu.hal.science/insu-03727102/file/JGR%20Atmospheres%20-%202016%20-%20Zhang%20-%20Improvement%20of%20stratospheric%20balloon%20GPS%20positioning%20and%20the%20impact%20on%20gravity%20wave.pdf; https://doi.org/10.1002/2015JD024596

International audience 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 30 s 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 3-10 m horizontal and 5 m vertical to 0.1 and 0.2 m, 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.