Sea-ice changes

[matthew-england-unsw]

Check 'em out

[pedrocol]

I performed a few more diagnostics on the sea ice, and I've found a lag between the two runs, specially at the beginning:

I then plot the sea-ice of the first month average and this difference seems to be everywhere. I'm wondering if the restart is correctly imported for the first leg of the run...

[adele-morrison]

This is just an issue with the time variable on the sea ice diagnostics. Copy the example sea ice notebook here closely and the problem goes away. See PR here.

[pedrocol]

Thanks Adele, all good

[adele-morrison]

Would be good to look at sea ice extent changes, so we can compare to obs. Is the Weddell change in extent as extreme as the change in volume?

[PaulSpence]

@pedrocol Where are you getting the 60 months of sea ice data from? When I use: start_time='2150-01-01' end_time='2155-01-01' session_name = '/g/data/e14/pc5520/model_data/access-om2/basal_melt_MOM5/basal_melt_MOM5.db' basal_melt_session = cc.database.create_session(session_name)

aice_Tfreezing_min =getACCESSdata(var='aice_m',start=start_time,end=end_time,exp=Tfreezing_min,freq='1 monthly',ses=basal_melt_session, minlon=geolon_t.xt_ocean.values.min(),maxlon=geolon_t.xt_ocean.values.max()) print(aice_Tfreezing_min.shape)

I get only 24 months ... ?

Also only 24 months of sea_ice data when running your code from here: https://github.com/pedrocol/basal_mom5-collaborative-project/blob/main/notebooks/seaice/seaice.ipynb

[adele-morrison]

What experiment are you loading Paul? I think only GPC006 has 5 years. If it’s not in that database you could try the other database I linked to earlier (in the example notebook also I think).

[pedrocol]

Sorry Paul, I made a mistake when setting the simulations parameters so I had to rename them, here is the up to date list of simulations

[PaulSpence]

oh great ... thought i had some (more) marbles :)

p

On Thu, Sep 8, 2022 at 8:42 AM Pedro @.***> wrote:

Sorry Paul, I made a mistake when setting the simulations parameters so I had to rename them, here is the up to date list of simulations

[image: Screenshot from 2022-09-07 19-40-10] https://user-images.githubusercontent.com/23285319/188995935-2ee438e2-e869-4f83-8105-41bb58a59af3.png

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Paul Spence, Assoc. Prof. ARC Future Fellow Institute for Marine and Antarctic Studies https://www.imas.utas.edu.au/ University of Tasmania, Hobart, Australia https://paulspence.github.io/

[pedrocol]

I performed a 1 year simulation with calving = 0.5 runoff and no basal melt. Below the plot of the sea ice volume time series. I confirm that the increase of the sea ice we have seen comes from the reduction of the runoff

[PaulSpence]

Sea ice concentration anomalies ... less in Amundsen more in Ross ... kinda same response as meltwater increase here: https://github.com/adele157/IAF-meltwater/issues/7#issuecomment-1218875096

[PaulSpence]

Minor changes in sea ice area:

Total and Anomaly for all Antarctic:

[PaulSpence]

Sea Ice Area anomalies:

SIA anoms are quite small - note Amundsen is only area with a decrease in SIA.

[PaulSpence]

Bigger changes in sea ice volume (since thickness is less a slave to the atmosphere):

Total and Anomaly for all Antarctic:

[PaulSpence]

SIV anomalies:

Switch to basal melt scheme seems to muck with the seasonal cycle a bit.

[PaulSpence]

Sea Ice Thickness:

[PaulSpence]

Sea Ice Growth via Frazil and Congel anomalies in Tfreezing_min:

Growth vars don;t really show why we get so much more ice in the Weddell Sea. Convergence or less summer melt? Unfortunately the dvidtt and dvidtd vars aren;t available.

[adele-morrison]

Closing, this uses the old simulations. New sea ice issue here.