Heat fluxes

[adele-morrison]

Plot the heat fluxes from runoff in the different runoff setups to see what impact the different formulations have (maps and time series). Also quantify the differences between the different setups compared to the total heat budget on the shelf.

Same issue with old simulation data is here.

[fabiobdias]

Here's a replication of the last year, annual average, horizontally integrated over the shelf (depth < 1000m) surface heat flux components:

Changes in SHF due to the frazil term seem to be the most important for the changes seen in the Net SHF; increasing frazil formation in the basal and icebergs runs agrees with our current discussion on excessive cold bias in the Amundsen Sea (here) and DSW export (here).

[fabiobdias]

The runoff term also changes between experiments, but its magnitude is much smaller than the other terms (not sure I'm doing smth wrong here?):

[fabiobdias]

Maps of runoff changes show a reduction in surface runoff in basal and ICB runs, as expected (showing here annual average of the last year simulated):

[pedrocol]

Thanks for this Fabio, the runoff temp is equal to the SST with a min threshold of 0°C, so whenever the SST is below 0°C there is positive heat flux. In the Basal run, part of the runoff is passed to the basal field, that's why you see a difference. In the ICB run, in addition of the basal extraction, we take the remaining part for the icb field.

[fabiobdias]

Thanks for the explanation Pedro.

Here's the last year maps of annual mean SHF due to frazil:

[adele-morrison]

In the bar plot above, does one of the columns correspond to the net heat flux? If not, it might be useful to add a bar for the net flux. Also, what's MH?

On Thu, 17 Aug 2023 at 12:51, Fabio Boeira Dias @.***> wrote:

Thanks for the explanation Pedro.

Here's the last year maps of annual mean SHF due to frazil:

[image: Screenshot 2023-08-17 at 12 50 29 pm] https://user-images.githubusercontent.com/8631257/261183186-e4e44ef5-c49f-489d-ba99-8a1e8ae8662b.png

— Reply to this email directly, view it on GitHub https://github.com/pedrocol/basal_mom5-collaborative-project/issues/66#issuecomment-1681531636, or unsubscribe https://github.com/notifications/unsubscribe-auth/ACA44U7KSNOFHWONUNJ25ITXVWBI5ANCNFSM6AAAAAA3KVZ54Q . You are receiving this because you authored the thread.Message ID: @.*** com>

[fabiobdias]

The net is the last 3 bars, given by:

Net = sfc_flux_from_runoff + sfc_hflux_coupler + sfc_hflux_pme + frazil_3d_int_z(+ temp_basalmix + temp_icbmix, for Basal and ICB expts).

MH is the mh_flux diagnosed by the residue of:

mh_flux = sfc_hflux_coupler - (swflx + lw_heat + sens_heat + evap_heat + fprec_melt_heat) following the previous issue #2.

_NB: I've previously not included the mhflux into the bar figure for the control experiment in my 1st comment; I've just fixed and replaced this figure

[fabiobdias]

For temp_basalmix/temp_icbmix, I've integrated them vertically by summing along the z-axis (assuming they are already depth-weighted?) - I guess these should be considered for the net surface heat flux?

[adele-morrison]

@fabiobdias what are the values in the bar plot above for the Net heat fluxes (to put on the results summary)?

[fabiobdias]

I'm running my script to get the numbers, but can't see the data on ik11 anymore (e.g., /g/data/ik11/outputs/access-om2-01/basal_melt_outputs/accessom2-GPC023). Have these been moved?

[pedrocol]

@fabiobdias Indeed, I moved everything so it is available for everyone

basal_gade_woa = '01deg_jra55v13_ryf9091_DSW_BasalGade_NoIcb'

icb_gade_woa = '01deg_jra55v13_ryf9091_DSW_BasalGade_YesIcb'

basal_nogade_woa = '01deg_jra55v13_ryf9091_DSW_BasalNoGade_NoIcb'

build database for these experiments:

session_name = '/g/data/ik11/databases/basal_melt_MOM5.db' basal_melt_session = cc.database.create_session(session_name)

dir_list = ['/g/data/ik11/outputs/access-om2-01/01deg_jra55v13_ryf9091_DSW_BasalGade_NoIcb/', '/g/data/ik11/outputs/access-om2-01/01deg_jra55v13_ryf9091_DSW_BasalGade_YesIcb/', '/g/data/ik11/outputs/access-om2-01/01deg_jra55v13_ryf9091_DSW_BasalNoGade_NoIcb']

cc.database.build_index(dir_list,basal_melt_session)

[fabiobdias]

So values for NET:

control = -37.35 TW BasalNoGade_NoIcb = -39.10 TW BasalGade_NoIcb = -47.51 TW BasalNoGade_YesIcbg = -54.03 TW

[fabiobdias]

And figure updated with all 4 experiments

[fabiobdias]

Final figure and key points:

• Increased negative NET SHF over the shelf in both Basal_gade (27.2%) and ICB (44.7%) experiments, dominated by negative SHF due to basal and icb mix;
• Coupler (i.e., radiative, turbulent and sea-ice related heat fluxes) changes only about 1.5-2.6%, resulting from small changes in nearly all components: SW/LW/Sens/Evap all decreases in Basal/ICB relative to CTRL, while sea-ice has a stronger negative SHF in Basal/ICB than CTRL;
• Frazil increases its positive SHF effect in Basal/ICB runs, offsetting some of the changes from basalmix/icbmix and coupler mentioned above.

[fabiobdias]