# Unraveling Gravity Wave Coupling from Surface to Stratosphere above La Réunion's Maïdo Observatory (21°S, 55.5°E) from Doppler and Rayleigh lidar observations

Samuel Trémoulu, Fabrice Chane Ming, Sergey Khaykin, Mathieu Ratynski, Alain Hauchecorne, Philippe Keckhut, Christophe Bellisario

► To cite this version:

Samuel Trémoulu, Fabrice Chane Ming, Sergey Khaykin, Mathieu Ratynski, Alain Hauchecorne, et al. Unraveling Gravity Wave Coupling from Surface to Stratosphere above La Réunion's Maïdo Observatory (21°S, 55.5°E) from Doppler and Rayleigh lidar observations. EGU General Assembly 2024, Apr 2024, Vienna, Austria. pp.EGU24-17591, 2024, 10.5194/egusphere-egu24-17591. insu-04513745

HAL Id: insu-04513745

https://insu.hal.science/insu-04513745

Submitted on 30 May 2024

**HAL** is a multi-disciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers.

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<figure><img src="image_1.png" /></figure>

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# Unraveling Gravity Wave Coupling from Surface to Stratosphere above La Réunion's Maïdo Observatory (21°S, 55.5°E) from Doppler and Rayleigh lidar observations

Samuel Trémoulu, Fabrice Chane Ming, Sergey Khaykin, Mathieu Ratynski, Alain Hauchecorne, Philippe Keckhut, Christophe Bellisario

► To cite this version:

Samuel Trémoulu, Fabrice Chane Ming, Sergey Khaykin, Mathieu Ratynski, Alain Hauchecorne, et al. Unraveling Gravity Wave Coupling from Surface to Stratosphere above La Réunion's Maïdo Observatory (21°S, 55.5°E) from Doppler and Rayleigh lidar observations. EGU General Assembly 2024, Apr 2024, Vienne, Austria. pp.EGU24-17591, 2024, 10.5194/egusphere-egu24-17591. insu-04513745

HAL Id: insu-04513745

https://insu.hal.science/insu-04513745v1

Submitted on 30 May 2024

HAL is a multi-disciplinary open access
archive for the deposit and dissemination of sci-
entific research documents, whether they are pub-
lished or not. The documents may come from
teaching and research institutions in France or
abroad, or from public or private research centers.

L'archive ouverte pluridisciplinaire HAL, est
destinée au dépôt et à la diffusion de documents
scientifiques de niveau recherche, publiés ou non,
émanant des établissements d'enseignement et de
recherche français ou étrangers, des laboratoires
publics ou privés.

<figure><img src="image_1.png" /></figure>

Distributed under a Creative Commons Attribution 4.0 International License
<figure><img src="image_2.png" /></figure>

# Unraveling Gravity Wave Coupling from Surface to Stratosphere above La Réunion's Maïdo Observatory (21°S, 55.5°E) from Doppler and Rayleigh lidar observations

Samuel Trémoulu<fnref n="1" />, Fabrice Chane Ming<fnref n="1" />, Sergey Khaykin<fnref n="2" />, Mathieu Ratynski<fnref n="2" />, Alain Hauchecorne<fnref n="2" />, Philippe Keckhut<fnref n="2" />, and Christophe Bellisario<fnref n="3" />

The study investigates the vertical wave coupling from the Earth's surface to the middle atmosphere over the Maïdo Observatory at La Réunion (21°S, 55.5°E). Wind velocity and temperature profiles from the ground-based instruments, including the LiWind Doppler Rayleigh-Mie and Li1200 Rayleigh Lidars, in conjunction with other observations (radiosoundings, COSMIC-2 radio-occultation, SABER) and ERA5 reanalysis, are analyzed to characterize gravity waves (GW) and their vertical propagation during the period from November 20th to November 24th, 2023. Notably, a tropospheric subtropical westerly jet manifested above La Réunion during this period and jet instabilities contributed to enhance GW activity in the troposphere. Wavelet methods are employed for denoising purposes and for highlighting multiscale GW from raw wind and temperature profiles. In particular, our analysis reveals the existence of a GW with a 5-km vertical wavelength and approximately a 24-hour period, propagating upward from lower troposphere to the middle atmosphere above La Réunion's Maïdo Observatory. Among others, the horizontal distribution of this structure surrounding La Réunion is examined using COSMIC-2 radio-occultation and SABER data. In addition, the ERA5 analysis also provides supporting evidence of such structures and GW filtering in the stratosphere.

<footnote n="1">¹LACy (UMR 8105, CNRS, Université de la Réunion, Météo-France), Saint-Denis de La Réunion, France</footnote>

<footnote n="2">²LATMOS-IPSL, CNRS/INSU, UMR 8190, Université Paris-Saclay, 78280 Guyancourt, France</footnote>

<footnote n="3">³ONERA, Chemin de la Hunière, 91123 Palaiseau, France</footnote>
<figure><img src="image_2.png" /></figure>

# Unraveling Gravity Wave Coupling from Surface to Stratosphere above La Réunion's Maïdo Observatory (21°S, 55.5°E) from Doppler and Rayleigh lidar observations

Samuel Trémoulu<fnref n="1" />, Fabrice Chane Ming<fnref n="1" />, Sergey Khaykin<fnref n="2" />, Mathieu Ratynski<fnref n="2" />, Alain Hauchecorne<fnref n="2" />, Philippe Keckhut<fnref n="2" />, and Christophe Bellisario<fnref n="3" />

The study investigates the vertical wave coupling from the Earth's surface to the middle atmosphere over the Maïdo Observatory at La Réunion (21°S, 55.5°E). Wind velocity and temperature profiles from the ground-based instruments, including the LiWind Doppler Rayleigh-Mie and Li1200 Rayleigh Lidars, in conjunction with other observations (radiosoundings, COSMIC-2 radio-occultation, SABER) and ERA5 reanalysis, are analyzed to characterize gravity waves (GW) and their vertical propagation during the period from November 20th to November 24th, 2023. Notably, a tropospheric subtropical westerly jet manifested above La Réunion during this period and jet instabilities contributed to enhance GW activity in the troposphere. Wavelet methods are employed for denoising purposes and for highlighting multiscale GW from raw wind and temperature profiles. In particular, our analysis reveals the existence of a GW with a 5-km vertical wavelength and approximately a 24-hour period, propagating upward from lower troposphere to the middle atmosphere above La Réunion's Maïdo Observatory. Among others, the horizontal distribution of this structure surrounding La Réunion is examined using COSMIC-2 radio-occultation and SABER data. In addition, the ERA5 analysis also provides supporting evidence of such structures and GW filtering in the stratosphere.

<footnote n="1">¹LACy (UMR 8105, CNRS, Université de la Réunion, Météo-France), Saint-Denis de La Réunion, France</footnote>

<footnote n="2">²LATMOS-IPSL, CNRS/INSU, UMR 8190, Université Paris-Saclay, 78280 Guyancourt, France</footnote>

<footnote n="3">³ONERA, Chemin de la Hunière, 91123 Palaiseau, France</footnote>