[ferret_users] Problems with eof_space first mode

[Aideen Foley <aideen.m.foley@xxxxxxx>]

I have a strange problem with the eof functions (in v5.51) and I wonder can anyone help me?

When I plot the first spatial mode for my data, it just doesn't make sense. I get an entirely negative plot, no gradients, yet this explains over 90% of the variance in the data. The second is more so what I would have expected the first mode to be.

I have tried this on numerous datasets and different variables. My data is for all of Europe, and when I run eof_space on the larger domain, I get good results, but when I try to extract the smaller domain I am interested in, I run into all this trouble.

Has anyone encountered anything like this before? If anyone can describe to me exactly how ferret processes data for the eof functions, that might help.

Thanks so much.