I wanted to ask this question since long, but have somehow missed till now.
In the FAQ for correlations and variances (http://ferret.pmel.noaa.gov/Ferret/faq/correlations-and-variances) it is advised to run var_n.jnl
to make the n/n+1 correction. I wonder if the correction is intended for variances and covariance only or also for correlation? The FAQ suggest noting the change in correl but end up depicting same value (as that before running var_n). Is this refering to some other change? - I assume not. Running var_n after variance script doesn't change value of correlation (but it does for variances and covariance).
Also the correction factor NDNM1 consider entire series in its computation, so if someone is interested in correlation for subset of time series between two variables, I think NDNM1 would not represent correct correction factor.
Many thanks in advance