[ferret_users] lagged spatial correlations

[Fabian Lienert <cccma-student-003@xxxxxxxx>]

Hi Ferret crowd,

I am calculating lagged spatial correlations between a monthly ENSO time series and SSTs 
(in space and time) using l=@shf:X and the go variance script.  
> From a lagged correlation analysis using a different software (R), I know 
that in the tropical Indian Ocean (10S-10N, 60E-100E), mean SSTs are lagging 
ENSO by 3 months when the lagged correlation is maximal.

Plotting the lagged spatial correlations in Ferret gives apparently the opposite result.

Case 1 when SSTs lead ENSO by 3 months. Correlation is max in Indian Ocean:
let q = ensots; let p = ssts[l=@shf:3]; go variance; fill correl

Case 2 when SSTs lag ENSO by 3 months. Correlation is much smaller in Indian Ocean than Case 1:
let q = ensots; let p = ssts[l=@shf:-3]; go variance; fill correl

Anybody knows what I am doing wrong?

Many thanks,
Fabian
--
Fabian Lienert                  |  Canadian Centre for Climate Modelling and Analysis
PhD Candidate                   |  Environment Canada
phone: +1(250)721-7211          |  University of Victoria
cccma-student-003@xxxxxxxx      |  P.O. Box 1700
http://www.cccma.bc.ec.gc.ca    |  Victoria, BC,  V8W 2Y2, Canada