Afficher la notice abrégée

Doppler wind measurements in Neptune’s stratosphere with ALMA

hal.structure.identifierLaboratoire d'études spatiales et d'instrumentation en astrophysique = Laboratory of Space Studies and Instrumentation in Astrophysics [LESIA]
dc.contributor.authorCARRIÓN-GONZÁLEZ, Óscar
hal.structure.identifierLaboratoire d'études spatiales et d'instrumentation en astrophysique = Laboratory of Space Studies and Instrumentation in Astrophysics [LESIA]
dc.contributor.authorMORENO, Raphael
hal.structure.identifierLaboratoire d'études spatiales et d'instrumentation en astrophysique = Laboratory of Space Studies and Instrumentation in Astrophysics [LESIA]
dc.contributor.authorLELLOUCH, Emmanuel
hal.structure.identifierLaboratoire d'Astrophysique de Bordeaux [Pessac] [LAB]
hal.structure.identifierASP 2023
hal.structure.identifierLaboratoire d'études spatiales et d'instrumentation en astrophysique = Laboratory of Space Studies and Instrumentation in Astrophysics [LESIA]
dc.contributor.authorCAVALIÉ, Thibault
hal.structure.identifierInstitut Pierre-Simon-Laplace [IPSL (FR_636)]
dc.contributor.authorGUERLET, Sandrine
hal.structure.identifierInstitut Pierre-Simon-Laplace [IPSL (FR_636)]
dc.contributor.authorMILCARECK, Gwenaël
hal.structure.identifierInstitut Pierre-Simon-Laplace [IPSL (FR_636)]
dc.contributor.authorSPIGA, Aymeric
hal.structure.identifierLaboratoire d'Astrophysique de Bordeaux [Pessac] [LAB]
dc.contributor.authorCLÉMENT, Noé
hal.structure.identifierLaboratoire d'Astrophysique de Bordeaux [Pessac] [LAB]
dc.contributor.authorLECONTE, Jérémy
dc.date.issued2023-06
dc.identifier.issn0004-6361
dc.description.abstractEnContext. Neptune’s tropospheric winds are among the most intense in the Solar System, but the dynamical mechanisms that produce them are still unclear. Measuring wind speeds at different pressure levels may help shed light on the atmospheric dynamics of the planet. Aims. The goal of this work is to directly measure winds in Neptune’s stratosphere with ALMA Doppler spectroscopy. Methods. We derived the Doppler lineshift maps of Neptune at the CO(3-2) and HCN(4-3) lines at 345.8 GHz ( λ ∼ 0.87 mm) and 354.5 GHz (0.85 mm), respectively. For that purpose, we used spectra obtained with ALMA in 2016 and recorded with a spatial resolution of ∼0.37″ on Neptune’s 2.24″ disk. After subtracting the planet’s solid rotation, we inferred the contribution of zonal winds to the measured Doppler lineshifts at the CO and HCN lines. We developed an MCMC-based retrieval methodology to constrain the latitudinal distribution of wind speeds. Results. We find that CO(3-2) and HCN(4-3) lines probe the stratosphere of Neptune at pressures of 2 −1.8 +12 mbar and 0.4 −0.3 +0.5 mbar, respectively. The zonal winds at these altitudes are less intense than the tropospheric winds based on cloud tracking from Voyager observations. We find equatorial retrograde (westward) winds of −180 −60 +70 m s −1 for CO, and −190 −70 +90 m s −1 for HCN. Wind intensity decreases towards mid-latitudes and wind speeds at 40°S are −90 −60 +50 m s −1 for CO and −40 −80 +60 m s −1 for HCN. Wind speeds become 0 m s −1 at about 50°S. We find that the circulation reverses to a prograde jet southwards of 60°S. Overall, our direct stratospheric wind measurements match previous estimates from stellar occultation profiles and expectations based on thermal wind equilibrium. Conclusions. These are the first direct Doppler wind measurements performed on the Icy Giants, opening up a new method for the study and monitoring of their stratospheric dynamics.
dc.description.sponsorshipSimulations et Observations de la dynamique atmosphérique d'Uranus et Neptune - ANR-20-CE49-0009
dc.language.isoen
dc.publisherEDP Sciences
dc.subject.enplanets and satellites
dc.subject.enatmospheres -planets and satellites
dc.subject.engaseous planets -radiative transfer
dc.title.enDoppler wind measurements in Neptune’s stratosphere with ALMA
dc.typeArticle de revue
dc.identifier.doi10.1051/0004-6361/202346621
dc.subject.halPhysique [physics]
bordeaux.journalAstronomy and Astrophysics - A&A
bordeaux.pageL3
bordeaux.volume674
bordeaux.peerReviewedoui
hal.identifierhal-04134641
hal.version1
hal.popularnon
hal.audienceInternationale
hal.origin.linkhttps://hal.archives-ouvertes.fr//hal-04134641v1
bordeaux.COinSctx_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:journal&rft.jtitle=Astronomy%20and%20Astrophysics%20-%20A&A&rft.date=2023-06&rft.volume=674&rft.spage=L3&rft.epage=L3&rft.eissn=0004-6361&rft.issn=0004-6361&rft.au=CARRI%C3%93N-GONZ%C3%81LEZ,%20%C3%93scar&MORENO,%20Raphael&LELLOUCH,%20Emmanuel&CAVALI%C3%89,%20Thibault&GUERLET,%20Sandrine&rft.genre=article


Fichier(s) constituant ce document

FichiersTailleFormatVue

Il n'y a pas de fichiers associés à ce document.

Ce document figure dans la(les) collection(s) suivante(s)

Afficher la notice abrégée