meanwhile I was able to collect all scientific data required for a scientifically correct multi-layer rendering of Jupiter's zonal cloud flows in Celestia(.Sci)
As to sharing the zonal flow data in tabular form, there is unfortunately the essential problem that most scientific data in this field are NOT freely available! Personally, I am lucky that I have complete access to the journals in question through the network of my laboratory.
But clearly, I am not allowed to publish these articles neither in total nor in part.
Having decades of experience in scientific computing, I have found a workaround that allows other people interested to work on this project, to use the essential flow data without accessing data tables in the costly journals.
Starting point is the above overlay of the zonal flow data on a display of Jupiter in spherical
projection. What is required, however, is the zonal velocity profile as function of latitude
, rather than of sin( latitude )
as implied in the spherical projection
The resulting velocity profile may then be overlaid on a Jupiter texture in simple cylindrical projection
. The next step is then a splitting of the texture into layers of corresponding velocity flow, etc...
What I (quickly) did is this:
1) With a few GIMP tricks, I extracted the overlaid zonal velocity graph from its spherical Jupiter texture background in this public NASA image
(see also above: http://forum.celestialmatters.org/viewt ... 9&start=16
2) The resulting plot was converted into a POSTSCIPT-2 file and the data read off into a text file with highest possible precision by means of some specialized scientific software (gv-readplot). The resulting tabular data were read into MAPLE where they could easily be processed further:
I replotted the read-in numerical data which looks like so:
As a check, this plot can be overlaid on the GIMP-extracted overlay plot above and proves very accurate. Note, the ordinate in this plot is proportional to sin( latitude )
NOT to latitude
as needed. However, within Maple a corresponding replot is very easy and looks like this
where now the ordinate is latitude in degrees. As you can see by comparison, the image appears now stetched at latitudes closer to the poles due to the applied re-mapping sin(latitude) = y => latitude = arcsin(y).
I made TWO final checks with these reprocessed data:
1) An overlay on the Jupiter texture in simple cylindrical projection
[Click on image for larger size]
In reality I used a 4k true-color texture from Cassini, here I have reduced it to 1k.
The agreement of the velocity profile with the above spherical projection is very good!
2) I compared the result to the NON-free data (involving latitude in tabular form) with excellent agreement.
Here you may download the tabular data (rel. zonal speed, latitude[degrees]), corresponding to the red curve above:
This text file contains 213 data points
, i.e. a high-resolution tabulation of the required data.
This way I was able to extract the desired data from a public NASA image without taking recourse to the NON-free journal articles.
I hope someone can make use of the results