Wondering what we should do about this.
To summarise:
01deg_jra55v140_iaf_cycle4
had a non-reproducible glitch at roughly 2011-09-27- This seems to have been a tiny initial perturbation, but the difference eventually became macroscopic due to chaos.
- I think the ocean data is therefore credible, since it’s just another realisation of turbulence from the same statistical distribution; the glitch was possibly as insignificant as the (reproducible) roundoff errors that happen all the time.
- We don’t know how often these non-reproducible glitches happen (since they are only detected if we re-run) so there may be several other examples of this issue in our datasets (we know there was another case in cycle 3 affecting all subsequent cycles).
- The main problem is we don’t have any sea ice data (except 6-hourly) that is consistent with the
01deg_jra55v140_iaf_cycle4
ocean data from 2011-09-27 onwards, and we can’t generate it due to the non-reproducible glitch in the original run.- the post-2002 non-6-hourly sea ice data in
01deg_jra55v140_iaf_cycle4
was actually generated by01deg_jra55v140_iaf_cycle4_rerun_from_2002
, and is inconsistent with the ocean state from 2011-09-27 onwards
- the post-2002 non-6-hourly sea ice data in