Hello. I am trying to compute a heat budget for a small region of the equatorial Pacific (e.g. 5S-5N, 120-140W), but I am having trouble with the advective terms. I have read several other threads with similar questions (here, here, and here) but I am still not obtaining reasonable values using the variables UET, VNT, and WTT. I am using POP2 on the gx1v6 grid.
My understanding is that you can compute the divergence in a cell using the following formula, e.g. for WTT:
( WTT[K+1] * cell_volume[k+1] - WTT[k] * cell_volume[k] ) / cell_volume[k] (units C/s)
I do something similar across the x and y directions as well:
( UET[i+1] * cell_volume[i+1] - UET * cell_volume ) / cell_volume (units C/s)
( VNT[j+1] * cell_volume[j+1] - VNT[j] * cell_volume[j] ) / cell_volume[j] (units C/s)
Presumably, this gives me the divergence for each direction; summing them should give me the total divergence in each cell.
Once this is done, I select only my domain of interest and sum, weighted by cell volume, across i, j and k. I assumed this would give me a total divergence into/out of my study region. However, the result is orders of magnitude different that I expect from a back of the envelope calculation.
Where am I going wrong? Any help would be greatly appreciated.
My understanding is that you can compute the divergence in a cell using the following formula, e.g. for WTT:
( WTT[K+1] * cell_volume[k+1] - WTT[k] * cell_volume[k] ) / cell_volume[k] (units C/s)
I do something similar across the x and y directions as well:
( UET[i+1] * cell_volume[i+1] - UET * cell_volume ) / cell_volume (units C/s)
( VNT[j+1] * cell_volume[j+1] - VNT[j] * cell_volume[j] ) / cell_volume[j] (units C/s)
Presumably, this gives me the divergence for each direction; summing them should give me the total divergence in each cell.
Once this is done, I select only my domain of interest and sum, weighted by cell volume, across i, j and k. I assumed this would give me a total divergence into/out of my study region. However, the result is orders of magnitude different that I expect from a back of the envelope calculation.
Where am I going wrong? Any help would be greatly appreciated.