Users Guide to Data From "The Solar Wind Interacting with and Orbiting Venus"
Stephen H. Brecht and Stephen A. Ledvina


Figure 1:

These matlab routines generate the plots for figure 1.  The routine 'soundspd.m' calculates the sound speed in the solar wind and compares it to the orbital speed of Venus and the trans-sonic envelope.  The contours of the Alfven speed are created in the routine 'alfvenspd.m'.


Figure 2:

The data is written in ascii and contains the x and y lengths of the simulation in units of Venus Radii, the location of Venus in the simulation, the number of points in the x and y directions and the solar wind density in units of 1/cm^3.  The data can be read with the follow Fortran statements (for example):

read(10,*)xlength,ylength
read(10,*)Venusx, Venusy
read(10,*)nx,ny

do j = 1,ny
   do i = 1,nx
      read(10,*)nsw(i,j)
   enddo
enddo

The location of each grid point can be calculated by:

dx = xlength/(dx-1)
dy = ylength/(dy-1)

do j = 1,ny
   y(j) = (j-1)*dx - Venusy
   do i = 1,nx
      x(i) = (i-1)*dx - Venusx

The calculations for x and y can be included in the above input section.

The density shown in the figure is the Log10 value of the density so to reproduce the figure the log of the density should be taken before plotting.

Figure 3:

Figure 3a:

Data for figure 3a was taken from Brecht and Ledvina, 2021 those interested in the data can find its' location listed at the end of that paper.

Figure 3b

This data file contains the magnitude of the magnetic field in nT within the region of 0.7 Rv - 2.0 Rv in the x-direction and +/- 2 Rv in the y-direction within the ecliptic plane.  This is an ASCII data file that was written with the following statements:

do j = 1,406
   do i = 1,126
      write(20,*)b(i,j)
   enddo
enddo

To reproduce the coordinates:

x = (i-1)*dx + 0.7,    where dx = 1.0267694e-02 Rv
y = (j-1)*dy + (-2.0)  where dy = 9.8522166e-03 Rv


Figure 4:

Figure 4a

Data for figure 4a is available from the PDS.  See the Data Availability Statement in Brecht and Ledvina [2021]. 

Figure 4b & c

The data file contains the sum of the O+ and O2+ densities in the ecliptic plane.  This is an  ASCII data file that contains  313026 data points.  The data was written with the following  statements:

do j = 1,609
   do i = 1,514
      write(30,*)den(i,j)
   enddo
enddo

The x-axis (i index) covers 5.2776 Venus radii, while the y-axis covers 6 Venus radii.  Thus dx = 0.0102877 Rv and dy = 0.00986842 Rv.  The planet is located at xp = 3 Rv and yp = 2.52943 Rv. So to convert to a planet centered coordinate system xpc = x-xp and ypc = y-yp.


Figure 5:

There are 2 data files: SW-Edep-Case1.dat, the stationary Venus case, and SW-Edep-Case2.dat, the orbiting Venus case.  Each data set is on a spherical grid Phi, Theta, Radius of dimensions (73,36,71).  The radial distance covers 100.0-450.0 km in altitude.  The Theta dimension goes from near the north pole at 2.5 deg to near the south pole at 177.5 deg.  The spacing between theta points is 5 degrees.  The phi points are in the azimuthal direction and cover the range of -2.5-362.5 deg. or 365 deg. So the values at phi(1) should be set to the values at phi(72) and the values at phi(73) should be set to the values at phi(2).

To set up the grid read in the data with:

nr = 71
nth = 36
nphi = 73

do k = 1,nr
  do j = 1,nth
    do i = 1,nph
      read(10,*)swedep(i,j,k)
    enddo
  enddo
enddo

Then set the phi boundary cells:

do k = 1,nr
  do j = 1,nth
    swedep(1,j,k) = swedep(nph-1,j,k)
    swedep(nph,j,k) = swedep(2,j,k)
  enddo
enddo

The data was plotted using matlab.  The contour plot was made using the slice routine though the altitude of 135 km.  The data for the curves in the other panels were taken by interpolating between the phi and theta points along the r dimension as needed.



Figure 6:

There are 4 data files.

The files dedt0.dat and dedt90.dat contain the time evolution of the electron number density at an altitude of 160 km, for solar zenith angles of 0 and 90 deg.

The files ne-vs-timesza*.dat contain the electron density profiles vs. altitude for solar zenith angles of 0 and 90 deg., plotted at 500 s intervals.