Define a MYSTIC 2D elevation input file (default: elevation2D.dat).  

mc_elevation_file file

 
The expected format of the elevation file is:  

Nx Ny dx dy ix iy elevation ...

 
where Nx and Ny are the number of grid boxes in x- and y-direction, dx and dy are the size of the grid boxes in km. In the second and the following lines the indices in x- and y-direction (ix=1…Nx, iy=1…Ny) and the elevation in km of each point are specified.

Attention: While the other files refer to grid boxes, the elevation is defined at grid points. It has to be this way because each ”elevation pixel” contains a surface which is defined by the four cornes of the pixel. If the grid covers an area of 200x200 km{}^{2} and the pixel sizes are dx = 1km and dy = 1km, the elevation has to be defined at 201x201 points (ix = 1 .. Nx, iy = 1 .. Ny).

Also, make sure that the elevation doesn't cross or even touch the 1D surface. Since the default altitude is 0 that means that the minimum elevation must be larger than 0!