Hi,
in The arguments first one is okay but the second argument will br the cut off frequency in your case it will be 1/120 (10 yr=120 months and you need to convert it to frequency domain) and the last argument is for weight..it is should be odd no..the more weight you give the smooth signal you get. Supoose you give 61 as a weight it will discard 30 data points from each end
There is another option in NCL i.e filwgts_lanczos function there you can do lowpass highpass and bandpass all just by altering 'ihp' value.
best
Hello Sandeep
you should look into this thread for understanding.
regards, saurabh