Freshwater bias in the ACCESS-OM2-01 in the sea ice zone of Southern ocean

Hi everyone,
I recently did a comparison between some observed ocean climatology (from WOD) against ACCESS-OM2-01 for the same regions (within small polygons in the Weddell Sea, East Antarctic, and Bellingshausen Sea sectors). The surface ocean in the model was much fresher than the observation. I am trying to write (part of the discussion) why this might be. In the Kiss et al (2020) paper there is a mention that the high-resolution model drifts towards surface freshening and this is partly offset by salinity restoration (section 4).

  • I was trying to find out how much effect the salinity restoration has south of 50S, does it act to make the SSS fresher or saline?
  • Does the forcing (JRA55-do) have a role to play? or is it mixing parametrization?

If you know of a follow-up analysis or if you can share your thoughts on what prescribed or derived factors lead to the freshening, I would be happy to get some direction.

  1. Map of regions used for comparison between the model and observation: Paper3_Fig1_OceanObs_on_map|175x500

  2. Comparison of the ocean and observed climatology in the East Antarctic region: EA_regional_ModelvsObs_64S_30032023|250x500

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Hey Stephy,

Not that this is a problem but you should be able to include images directly in your post (so that it has a bit more visual impact and to make it easier to view your lovely figures):

I used the little “upload” button on the menu bar of the editor to include those figures.

Sorry my feedback is just related to technical features of the forum.

Cheers

Aidan

That’s a very small number of profiles. Have you looked at the Pauthenet et al. 2021 climatology? It includes seal data (not sure how far north it goes though).

Also +1 for embedding figures in posts. I pretty much never click on links, but it’s hard to ignore pretty pictures when they show up in my email. :slight_smile:

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Thank you, Aiden,

I originally tried sharing four figures with caption as a word document (it doesn’t take that format). I made it into a powerpoint (as it was an accepted format). It didn’t let me attach it. Finally I embedded individual figures, and it will only allow two figures. I think there’s so many rules to get by… I understand as a new post it may not be expecting multiple attachments etc, but is there a way to toggle with these controls?

Stephy

Hi Adele,
No, I had not come across that dataset, since I am submitting my thesis soon, I worked with the WOD data that Will already had. But it is something to look into before I try to submit the manuscript at a later stage :slight_smile:
Thank you for your comment in the slack channel and on my pretty figures :smiley:

I am sharing the figures for Bellingshausen Sea and Weddell Sea here (as I could not attach them in the original post) In all three regions the surface (above the permanent pycnocline) is much fresher in the model than the respective observation profiles.
Bellingshausen Sea

In the thesis, I was planning to write briefly on the effects of the following three factors on surface freshwater levels, and I am trying find relevant resources or papers.

  1. Mixing parametrization
  2. Surface forcing
  3. Salinity restoration
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Weddell Sea

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