The Aeolus satellite: a new look at gravity waves and tropical dynamics - INSU - Institut national des sciences de l'Univers
Communication Dans Un Congrès Année : 2024

The Aeolus satellite: a new look at gravity waves and tropical dynamics

Sergey Khaykin
Alain Hauchecorne
  • Fonction : Auteur
  • PersonId : 914935
Joan Alexander
Alexis Mariaccia
Philippe Keckhut
  • Fonction : Auteur
  • PersonId : 918122
Samuel Tremoulu
  • Fonction : Auteur
  • PersonId : 1392634

Résumé

The European Space Agency's Aeolus satellite, equipped with the Atmospheric LAser Doppler INstrument (ALADIN), provides comprehensive global wind profiling, offering valuable insights into convection-induced gravity waves (GWs) in the upper troposphere and lower stratosphere (UTLS). This study analyzes Aeolus-derived wind data alongside ECMWF ERA5 reanalysis, revealing a migrating hotspot of enhanced GW activity. This activity transitions from the Indian Ocean during the Boreal Summer to the Maritime Continent in Boreal Winter, correlating strongly with convective activity as evidenced by variability in outgoing longwave radiation. The results underscore the importance of Aeolus in improving the representation of convective-induced GWs in ERA5, particularly in the under-sampled Indian Ocean region, thus enhancing our understanding of GW phenomena in the UTLS. While the benefits of Aeolus global wind profiling are straightforward, important limitations exist, particularly when studying extratropical UTLS dynamics. We identify and characterize these limitations in our study, focusing on the Range Bin Setting (RBS) of Aeolus. This RBS adjusts dynamically based on seasonal and geographical variations, affecting our ability to measure and interpret gravity wave dynamics accurately. We also examine oscillatory perturbations (OPs) identified in Aeolus data, particularly between 12 and 19 km altitudes, displaying a unique oscillatory signature. These OPs emerge prominently above high-albedo regions such as Greenland and Antarctica. The nature of these oscillations remains unexplained although the dark current anomalies on the instruments (hot pixels) may amplify these oscillations without explaining their inherent characteristics. The absence of these phenomena in GNSS Radio Occultation data suggests that the observed perturbations in Aeolus data are not related to gravity waves but are likely linked to the satellite's specific observational characteristics. These variations introduce substantial uncertainty into our models and highlight the necessity for developing more precise metrics that can reliably detect and interpret such phenomena.
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Dates et versions

insu-04682764 , version 1 (30-08-2024)

Identifiants

  • HAL Id : insu-04682764 , version 1

Citer

Mathieu Ratynski, Sergey Khaykin, Alain Hauchecorne, Joan Alexander, Alexis Mariaccia, et al.. The Aeolus satellite: a new look at gravity waves and tropical dynamics. 16th International Workshop on Technical and Scientific Aspects of iMST Radar and Lidar (MST16/iMST3), Sep 2024, Rostok, Germany. ⟨insu-04682764⟩
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