J/A+A/554/A74 Jupiter's zonal winds in 2011 (Barrado-Izagirre+, 2013)
Jupiter's zonal winds and their variability studied with small size telescopes.
Barrado-Izagirre N, Rojas J.F., Hueso R., Sanchez-Lavega A., Colas F.,
Dauvergne J.L., Peach D. (the IOPW Team)
<Astron. Astrophys. 554, A74 (2013)>
=2013A&A...554A..74B 2013A&A...554A..74B
ADC_Keywords: Planets ; Radial velocities
Keywords: planets and satellites: atmospheres - giant planet atmospheres -
dynamics - telescopes
Abstract:
The general circulation of Jupiter's atmosphere at cloud level is
dominated by a system of zonal jets that alternate in direction with
latitude. The winds, measured in high-resolution images obtained by
different space missions and the Hubble Space Telescope, are overall
stable in their latitude location with small changes in intensity at
particular jets. However, the atmosphere experiences repetitive
changes in the albedo of particular belts and zones that are subject
to large-scale intense disturbances that may locally influence the
profile.
The lack of high-resolution images has not allowed the wind system to
be studied with the regularity required to assess its stability with
respect to these major changes or to other types of variations (e.g.,
seasonality). To amend that, we present a study of the zonal wind
profile of Jupiter using images acquired around the 2011 opposition by
a network of observers operating small-size telescopes with apertures
in the range 0.20-1m.
Using an automatic correlation technique, we demonstrate the
capability to extract the mean zonal winds in observing periods close
to the opposition. A broad collaboration with skilled amateur
astronomers opens the possibility to regularly study short- and
long-term changes in the jets of Jupiter.
We compare the 2011 Jovian wind profile to those previously obtained.
The winds did not experience significant short-term changes over 2011
but show noteworthy variations at particular latitudes when compared
with wind profiles from previous years. Most of these variations are
related to major changes in the cloud morphology of the planet, in
particular at 7°N where an intense eastward jet varies around
40m/s in its intensity according to the development or not of the
"dark projection" features, confirming previous results.
Description:
Averaged mean zonal winds from IOPW observations in 2011. φ is
the planetocentric latitude, σ the standard deviation and n the
number of measured vectors.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 43 51 IOPW team's observations
(http://pvol2.ehu.eus/pvol2)
table3.dat 22 124 Averaged mean zonal winds from International Outer
Planet Watch (IOPW) observations in 2011
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 10 A10 "date" Obs.Date Observation date
12- 16 A5 "h:m" Obs.Time Observation time
18- 38 A21 --- Observ Observer name
40- 43 I4 mm Diam ? Telescope diameter
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 5 F5.1 deg phi [-60/63] Planetocentric latitude φ
7- 12 F6.2 m/s [-53/154]? Mean zonal velocity
14- 18 F5.2 m/s e_ [0.9/41.2]? standard deviation σ
20- 22 I3 --- n [2/737]? Number of velocity vectors in each bin
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Acknowledgements:
Naiara Barrado-Izagirre, naiara.barrado(at)ehu.es
(End) N. Barrado-Izagirre [UPV/EHU, Spain], P. Vannier [CDS] 21-Apr-2013