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ajdawson / eofs

EOF analysis in Python
http://ajdawson.github.io/eofs/
GNU General Public License v3.0
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Issue with explained variance #116

Closed sryan288 closed 2 years ago

sryan288 commented 5 years ago

Hello,

I am using the eofs package with the xarray option and ran into a problem with the explained variance. I am comparing sea surface temperature from a satellite product (HadISST) and model output from a global circulation model. See the jupyter notebook here

https://github.com/sryan288/Share/blob/master/EOF_HadISST_vs_ORCA.ipynb

The spatial patterns and PCs for the first two modes look very similar, however, the explained variance for the observations (sst array) is about 60% while it is below 40% for the model (orca array). Generally, the first few modes summed up explain an uncommonly small percentage of the total variance for the model data.

As a test I saved both fields that I plug into the EOF functions, read them into Matlab and performed an EOF analysis there, where I get an explained variance around 60 % for the first modes in both data sets.

I am fairly new to Python and there could definitely be a mistake in my code but I couldn't find anything and don't understand what is going on.

I would greatly appreciate any kind of help! Svenja

ajdawson commented 2 years ago

I am closing this old issue, the linked notebook is no longer available. I suspect the answer may partly lie in doing the analysis at different spatial resolutions but only speculation.