picking a non-leap year

[reneschubert]

Name of your institution / research group

GEOMAR / Ocean Dynamics

Information request

Our simulation period is 2018 - 2023, with a secondary spin-up from 2018-mid 2020.
So, we cant cut 2024 directly. As 2024 is a leap year, it is probably easiest to cut the SWOT-like data from another leap year, however 2020 is partially affected by the secondary spin-up.
What we do for our own SWOT validation is to take for each SWOT track the first science phase time (averaged over our investigated domain) and then go back and forward in steps of 20.8646 days (which is the average increment between two measurements) and pick the tracks from the respective model output hourly means for the full investigable model period, say 2021 - 2023 and then compare it to SWOT 2024. This comes along with the restriction, that there are of cause no information available for the pre-science respectively pre-SWOT phase in terms of quality flags and small deviations associated with the cross-distance.

My question is: How important is for the SWOTMIP that a leap year is probed using the quality flags / cross-distant information from the SWOT 2024 observations? I can also imagine to add another day to a non-leap year and then handle the data as if it would be 2024.

[contreras-m]

Thanks for your question and sorry for my late reply.

Indeed, year 2024 is a leap year, and the simplest option of top get rid of the measurements close to Feb 29.  The analysis we are planning are mostly statistical, meaning that each realization of SSH is considered independently from the others. It would be great if you could provide several years of data.