Gigantic Vortices From Barotropic Instability Observed in the Atmosphere of Venus

Until recently, the lower to middle cloud region of Venus had been supposed to be dynamically quiet, accommodating nearly steady superrotating westward flow. However, observations of the regions by Akatsuki, the latest Venus orbiter operating since 2015, have revealed a variety of cloud features ind...

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Detalles Bibliográficos
Autores: Horinouchi, Takeshi, Satoh, Takehiko, Peralta Calvillo, Javier
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2023
País:España
Institución:Universidad de Sevilla (US)
Repositorio:idUS. Depósito de Investigación de la Universidad de Sevilla
OAI Identifier:oai:idus.us.es:11441/158466
Acceso en línea:https://hdl.handle.net/11441/158466
https://doi.org/10.1029/2022GL101633
Access Level:acceso abierto
Palabra clave:Barotropic instability
Cloud
Geophysical fluid dynamics
Planetary atmospheres
Venus
Vortex street
Descripción
Sumario:Until recently, the lower to middle cloud region of Venus had been supposed to be dynamically quiet, accommodating nearly steady superrotating westward flow. However, observations of the regions by Akatsuki, the latest Venus orbiter operating since 2015, have revealed a variety of cloud features indicative of vortices and waves. Here we report another, and arguably the most conspicuous, example. Akatsuki's near-infrared imager IR2 captured gigantic vortices rotating cyclonically on 25 August 2016. By using winds estimated by cloud tracking, the feature is shown to be quantitatively consistent with barotropic instability. The size of the vortices (∼1,000 km) and their spacing (∼2,500 km) are more than several times greater than the vortex-like features reported previously from the observations of Venus, and they are also greater than the largest barotropic instability observed in the Earth's troposphere.