However, in this particular example, we have a great
deal of weather noise over this short interval, therefore the spread of the runs due to weather is key.
Kleeman, R., Y. Tang, and A.M. Moore, 2003: The calculation of climatically relevant singular vectors in the
presence of weather noise as applied to the ENSO problem.
This is useful for short data records (such as those retrieves by satellite) where there is a
lot of weather noise one wouldn't expect the model to capture.
Yes, the Arctic warms and cools in consonant with the rest of the globe, but with much local excursions and
plenty of weather noise and cyclical climate perturbations contributing to the overall picture.
Furthermore, in a subseasonal forecast, some kind of time average (e.g. weekly or pentad mean) is usually used, which removes
part of the weather noise.
As mentioned above, with a single realisation, there is going to be an
amount of weather noise that has nothing to do with the forcings.