Wind mapping in Venus' upper mesosphere with the IRAM-Plateau de Bure interferometer
| Autor: | Mark Gurwell, Emmanuel Lellouch, Raphael Moreno, Hideo Sagawa, Arielle Moullet |
|---|---|
| Přispěvatelé: | Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Centre for Astronomy, Harvard University [Cambridge], Center for Mathematics and Physics, University of Aizu, Harvard University |
| Rok vydání: | 2012 |
| Předmět: |
010504 meteorology & atmospheric sciences
media_common.quotation_subject FOS: Physical sciences Venus Zonal and meridional 01 natural sciences 0103 physical sciences 010303 astronomy & astrophysics Image resolution ComputingMilieux_MISCELLANEOUS 0105 earth and related environmental sciences media_common [PHYS]Physics [physics] Earth and Planetary Astrophysics (astro-ph.EP) biology Wind field Plateau de Bure Interferometer Astronomy and Astrophysics Wind direction Geodesy biology.organism_classification Interferometry 13. Climate action Space and Planetary Science Sky [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph] Geology Astrophysics - Earth and Planetary Astrophysics |
| Zdroj: | Astronomy and Astrophysics-A&A Astronomy and Astrophysics-A&A, EDP Sciences, 2012, 546, pp.A102. ⟨10.1051/0004-6361/201118451⟩ Astronomy and Astrophysics-A&A, 2012, 546, pp.A102. ⟨10.1051/0004-6361/201118451⟩ |
| ISSN: | 0004-6361 |
| DOI: | 10.48550/arxiv.1202.5279 |
| Popis: | The dynamics of the upper mesosphere of Venus (~85-115 km) have been characterized as a combination of a retrograde superrotating zonal wind (RSZ) with a subsolar-to-antisolar flow (SSAS). Numerous mm-wave single-dish observations have been obtained and could directly measure mesospheric line-of-sight winds by mapping Doppler-shifts on CO rotational lines, but their limited spatial resolution makes their interpretation difficult. By using interferometric facilities, one can obtain better resolution on Doppler-shifts maps, allowing in particular to put firmer constraints on the respective contributions of the SSAS and RSZ circulations to the global mesospheric wind field. We report on interferometric observations of the CO(1-0) line obtained with the IRAM-Plateau de Bure interferometer in November 2007 and June 2009, that could map the upper mesosphere dynamics on the morning hemisphere with a very good spatial resolution (3.5-5.5"). All the obtained measurements show, with a remarkably good temporal stability, that the wind globally flows in the (sky) East-West direction, corresponding in the observed geometry either to an unexpected prograde zonal wind or a SSAS flow. A very localized inversion of the wind direction, that could correspond to a RSZ wind, is also repeatedly detected in the night hemisphere. The presence of significant meridional winds is not evidenced. Using models with different combinations of zonal and SSAS winds, we find that the data is best reproduced by a dominant SSAS flow with a maximal velocity at the terminator of ~200 m/s, displaying large diurnal and latitudinal asymmetries, combined with an equatorial RSZ wind of 70-100 m/s, overall indicating a wind-field structure consistent with but much more complex than the usual representation of the mesospheric dynamics. Comment: Accepted for publication in A&A |
| Databáze: | OpenAIRE |
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