[Wrf-users] IJ coordinate

[Steven Utembe]

Dear Wrf-users,

I need to trace a ray through wrf 3D grid boxes (given sun's position as in
elevation and forward azimuth or bearing). In order to do this i need to
know where I am in the grid box. I know wrf grids are numbered west to
east(i) and south to north(j). Given a latitude and longitude I can work
out the i and j indices (using NCL's wrf_user_ll_to_ij script) which is a
grid nearest my lat lon. The wrf_user_ll_to_ij function can return integer
ij or real ij e.g i=38.46 and j=34.2. How do I know whether this
corresponds to the edge or an position inside the grid? Does position ij
refer to the edges or halfway inside the grid?

Please help!

Best regards,

Steve

Steve
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