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Kishore,
ferret is exactly made for such tasks. But the detailed method depends on what kind of data you have. What is "land" as a dimension? To calculate sums, integrals or averages ferret has the transformations @sum @din and @ave. If you mean something like a time series of average humidity over land, you need a land mask. Say the mask is 1 for land cells and 0 for ocean cells. How to prepare this mask is a good question. Possibly it comes with your shum - data. Otherwise ferret includes some topographic data base. To proceed transform the land mask to "missing" over ocean, that means "excluded" from averaging or integrating. let mask_missing = 1/ mask ! Dividing by zero produces a "missing" value. Now find let humidity well defined over land but missing over the ocean let shum_land = shum * mask_missing Now you may average or integrate over lat and lon let shum_land_ave = shum_land[x=@ave, y=@ave] let shum_land_int = shum_land[x=@din, y=@din] shum_land_ave and shum_land_int have the remaining dimension "time". (note, if shum would be defined also with vertical levels, the averaged quantities inherit dimensions "time" and "height" without any change in the syntax of the calculation. From this point of view ferret is a very special and skilled animal.) For more details please consult the manual and the tutorial. Hope this helps to get you started. Best, Martin Am 12.02.2016 um 08:42 schrieb Kishore Ragi:
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