ferret question

[Mark Carson <mark.carson@xxxxxxxx>]

Hi all,

I hope I can pose this question somewhat clearly.  I have a temperature 
dataset that is gridded in time only with a grid spacing of 1 day over 
50 years span (18628 time points).  I would like to subtract the WOA01 
monthly mean climatology from the data, but it is gridded in 12 time 
points - months.  How can I subtract the proper month's value from my 
dataset when, say, January occurs over and over again throughout the 50 
years, and making sure I'm subtracting it from the proper days that 
would be the days of January in each year?  Is this doable in Ferret?

Thanks for any thoughts or info!

Mark Carson