[ecco-support] Question about the inconsistency between ECCO Version 4 Release 1 and the latest Version 4 Release 3

[Fenty, Ian G (329C)]

Qi,

Thank you for your question.  I am fairly certain that there are no in situ ocean temperature measurements in front of Totten used to constrain any ECCO state estimate at this time.  The recent observations in front of Totten published in Rintoul et al., 2016 have not yet been incorporated.

Looking at the figure S5 it appears that all three products are actually quite different quantitatively (SOSE: temperature range from +1 to -1 over a few years, ECCOv4R1: +.6 to +.2 over 24 years, ECCO2: 0.6 to -1.5 over 24 years.)  The ECCOv4 solutions are almost certainly too coarse to adequately resolve circulation on the continental shelf in front of Totten.  The warming over the first few years of the ECCOv4R3 solution may be due to spin-up.  After 1998 the ECCOv4R3 solution does show a vaguely similar qualitative pattern of cooling, slight warming, then cooling again.    However, I’m afraid that without observations it is not really possible to determine which of these solutions is closest to reality or if the qualitative changes reported by Li are real.

In the meanwhile, please take a look at Khazendar et al., 2013 Observed thinning of Totten Glacier is linked to coastal polynya variability in Nature Communications for a discussion on how sea ice can affect ocean temperatures on the shelf in the region.

Ian

-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://mailman.mit.edu/pipermail/ecco-support/attachments/20180329/436fda0a/attachment.html