Cassini Saturn polar velocity fields
The data comprise two 2-dimensional gridded maps of horizontal wind measurements covering the north and south polar regions of Saturn, as previously published by Antuñano et al. (2015). As fully described in that paper, these measurements were derived from sets of Cassini Orbiter Imaging Sub-System...
| Main Authors: | , , , , |
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| Format: | Dataset |
| Language: | English |
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University of Oxford
2021
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| _version_ | 1797076437500428288 |
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| author | Antuñano, A del Río Gaztelurrutia, T Hueso, R Read, P Sanchez-Lavega, A |
| author2 | Antuñano, A |
| author_facet | Antuñano, A Antuñano, A del Río Gaztelurrutia, T Hueso, R Read, P Sanchez-Lavega, A |
| author_sort | Antuñano, A |
| collection | OXFORD |
| description | The data comprise two 2-dimensional gridded maps of horizontal wind measurements covering the north and south polar regions of Saturn, as previously published by Antuñano et al. (2015). As fully described in that paper, these measurements were derived from sets of Cassini Orbiter Imaging Sub-System (ISS) Wide Angle Camera (WAC) and Narrow Angle Camera (NAC) images using the continuum band CB2 and CB3 filters, acquired for the northern hemisphere in June 2013 and for the southern hemisphere using WAC CB2 and CB3 images taken in October 2006 and December 2008. Additional NAC images using the CB2 and red filters taken in July 2008 were also used to analyse the southern polar vortex. The WAC images covered a region extending from a planetocentric latitude of around 60-65 degrees to each pole (apart from a segment in longitude between around 35 - 110 degrees W) with a horizontal resolution equivalent to around 0.05 degrees latitude (around 50km) per pixel, while NAC images were mostly used for the polar vortices, with a resolution equivalent to around 0.01 degrees latitude (around 10 km) per pixel.
Horizontal velocities were obtained using semi-automated image correlation methods between pairs of images separated in time by intervals of approximately 1-10 hours. The correlation algorithm used pixel box sizes of 23 x 23 (in the north) or 25 x 25 (in the south), leading to a spatial resolution of the velocity vectors equivalent to around 1 degree latitude or 1000 km outside the polar vortices, reducing to around 0.2 degrees or 200 km within the polar vortices themselves. The automatically generated velocity vectors were supplemented by a small number (around 1% of the total) of vectors obtained manually from the motion of visually identified cloud tracers. The estimated measurement uncertainty on each vector was around 5-10 m/s. The original velocity vectors from Antuñano et al. (2015) were interpolated onto a regular latitude-longitude grid using convex hulls and Delauney triangulation via the QHULL routine of the Interactive Data Language (IDL). The final datasets are held on a regular grid separated by 3-4 degrees in longitude and 0.23 degrees in latitude. Data are stored as two text files, tabulating the latitude and (west) longitude of each point and the eastward and northward velocity components respectively in units of m/s.
Reference: Antuñano,A., del Río-Gaztelurrutia,T., Sánchez-Lavega,A., & Hueso, R. (2015). Dynamics of Saturn’s polar regions. J. Geophys. Res.: Planets, 120, 155–176. doi: 10.1002/2014JE004709 |
| first_indexed | 2024-03-07T00:03:46Z |
| format | Dataset |
| id | oxford-uuid:76da2bd5-ac16-4df9-b6d4-4052b99ed720 |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-07T00:03:46Z |
| publishDate | 2021 |
| publisher | University of Oxford |
| record_format | dspace |
| spelling | oxford-uuid:76da2bd5-ac16-4df9-b6d4-4052b99ed7202022-03-26T20:19:13ZCassini Saturn polar velocity fieldsDatasethttp://purl.org/coar/resource_type/c_ddb1uuid:76da2bd5-ac16-4df9-b6d4-4052b99ed720Atmospheric circulationPlanetary meteorologyEnglishHyrax DepositUniversity of Oxford2021Antuñano, Adel Río Gaztelurrutia, THueso, RRead, PSanchez-Lavega, AAntuñano, Adel Río Gaztelurrutia, TSanchez-Lavega, AThe data comprise two 2-dimensional gridded maps of horizontal wind measurements covering the north and south polar regions of Saturn, as previously published by Antuñano et al. (2015). As fully described in that paper, these measurements were derived from sets of Cassini Orbiter Imaging Sub-System (ISS) Wide Angle Camera (WAC) and Narrow Angle Camera (NAC) images using the continuum band CB2 and CB3 filters, acquired for the northern hemisphere in June 2013 and for the southern hemisphere using WAC CB2 and CB3 images taken in October 2006 and December 2008. Additional NAC images using the CB2 and red filters taken in July 2008 were also used to analyse the southern polar vortex. The WAC images covered a region extending from a planetocentric latitude of around 60-65 degrees to each pole (apart from a segment in longitude between around 35 - 110 degrees W) with a horizontal resolution equivalent to around 0.05 degrees latitude (around 50km) per pixel, while NAC images were mostly used for the polar vortices, with a resolution equivalent to around 0.01 degrees latitude (around 10 km) per pixel. Horizontal velocities were obtained using semi-automated image correlation methods between pairs of images separated in time by intervals of approximately 1-10 hours. The correlation algorithm used pixel box sizes of 23 x 23 (in the north) or 25 x 25 (in the south), leading to a spatial resolution of the velocity vectors equivalent to around 1 degree latitude or 1000 km outside the polar vortices, reducing to around 0.2 degrees or 200 km within the polar vortices themselves. The automatically generated velocity vectors were supplemented by a small number (around 1% of the total) of vectors obtained manually from the motion of visually identified cloud tracers. The estimated measurement uncertainty on each vector was around 5-10 m/s. The original velocity vectors from Antuñano et al. (2015) were interpolated onto a regular latitude-longitude grid using convex hulls and Delauney triangulation via the QHULL routine of the Interactive Data Language (IDL). The final datasets are held on a regular grid separated by 3-4 degrees in longitude and 0.23 degrees in latitude. Data are stored as two text files, tabulating the latitude and (west) longitude of each point and the eastward and northward velocity components respectively in units of m/s. Reference: Antuñano,A., del Río-Gaztelurrutia,T., Sánchez-Lavega,A., & Hueso, R. (2015). Dynamics of Saturn’s polar regions. J. Geophys. Res.: Planets, 120, 155–176. doi: 10.1002/2014JE004709 |
| spellingShingle | Atmospheric circulation Planetary meteorology Antuñano, A del Río Gaztelurrutia, T Hueso, R Read, P Sanchez-Lavega, A Cassini Saturn polar velocity fields |
| title | Cassini Saturn polar velocity fields |
| title_full | Cassini Saturn polar velocity fields |
| title_fullStr | Cassini Saturn polar velocity fields |
| title_full_unstemmed | Cassini Saturn polar velocity fields |
| title_short | Cassini Saturn polar velocity fields |
| title_sort | cassini saturn polar velocity fields |
| topic | Atmospheric circulation Planetary meteorology |
| work_keys_str_mv | AT antunanoa cassinisaturnpolarvelocityfields AT delriogaztelurrutiat cassinisaturnpolarvelocityfields AT huesor cassinisaturnpolarvelocityfields AT readp cassinisaturnpolarvelocityfields AT sanchezlavegaa cassinisaturnpolarvelocityfields |