Data from: Long wavelength topography of Io and predicted isostatic topography resulting from spatial variation in Io's tidal heating
Data files
Apr 09, 2024 version files 236.29 KB
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Io_SphHarmCoef_Norm.txt
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README.md
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ThomasLimbP.txt
Abstract
After deriving equations that describe the response of isostatic, long-wavelength topography to spatial variation of Io's tidal heating, we use these equations to plot this response as a function of tidal heat variation. We compare the possible range of topographic amplitude to the observed global shape of Io (after subtraction of its hydrostatic shape).
README: Data from: Long wavelength topography of Io and predicted isostatic topography resulting from spatial variation in Io's tidal heating
https://doi.org/10.5061/dryad.b8gtht7k6
We include Io limb profile topography and the spherical harmonic coefficients of topography in degrees 3 and 4. Then, we utilize our derived equations to demonstrate a model of topography as a function of variation in tidal heating for comparison.
Description of the data and file structure
We include 2 datasets and one program script.
ThomasLimbP.txt contains Io limb profile topography, and is provided courtesy of Peter Thomas. The Galileo image used for each profile is listed in Table 1 of White et al. (2014, JGR: Planets 119(6), pp. 1276-1301). All the profiles are included in the same file, where the first column is the longitude (°W), the second column is latitude (°N), and the third column is the topography in km with respect to the reference ellipsoid defined in Thomas et al. (1998, *Icarus 13*5(1), pp. 175-180).
Io_SphHarmCoef_Norm.txt contains spherical harmonic coefficients of topography in degrees 3 and 4. These were generated from the limb profile topography using the method summarized in White et al. (2014) with smoothing parameter r=3*10^7. The columns are as follows: degree l, order m, index 1 or -1, coefficient, uncertainty. The index is 1 for the C_{l,m} coefficient and -1 for the S_{l,m} coefficient. The spherical harmonic coefficient is listed in km, as normalized by the method described in Nimmo et al. (2011, JGR: Planets 116(E11)). Note: some coefficients may feature a sign error as described in Nimmo et al. (2013, JGR: Planets 118(12)). The correct C coefficients must be multiplied by (-1)^m, while the correct S coefficients must be multiplied by (-1)^(m+1).
Sharing/Access information
n/a
Code/Software
Use python 3 to run io_heat_flux_topography.py and reproduce the figure from our paper. Required modules include numpy and matplotlib.
Methods
The dataset for Io limb topography used in White et al. (2014, JGR: Planets, 119(6)) has been provided courtesy of Peter Thomas. This topography is measured with respect to the reference ellipsoid of Io (Thomas et al., 1998, Icarus 135(1)).
Spherical harmonic degree 3 and 4 coefficients were generated with the method summarized in White et al. (2014), using smoothing parameter r = 3*10^7.