Hi, Ferret's averages are weighted averages, using only valid data, weighted by the grid-cell size. For grids that represent longitude and latitude, the average (and integrals) use correct area on the surface of the earth. Here is the documentation about how transformations are done: http://ferret.pmel.noaa.gov/Ferret/documentation/users-guide/variables-xpressions/XPRESSIONS#GeneralInfo
Scroll down in that section to see the specific defintion of @AVE. A general technique for understanding how Ferret makes, is to set up a simple example, such as a variable whose value is 1 everywhere, and apply the operations you are using to that variable, perhaps on a very coarse grid so you can more easily study the values. There's an example of that sort of thing, using a time average operation, in this FAQ, How can I determine the averaging weights when regridding with @AVE? Ansley
On 11/27/2016 11:36 PM, saurabh rathore
wrote:
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