H compset experiments

Robert Osinski, Wieslaw Maslowski, Jaromir Jakacki, Jackie Clemant-Kinney, Andrew Roberts

RASM workshop, NPS, May 2012

Channel problem

Volume transport through the

channel

Scalability of H compset

Timing profile

ExperimentsH_NC2_AL0_ST0_CP0_D0_T0

Inter-annually varying forcing (IAF), as developed by Large and Yeager (2008) at NCAR: CORE2

Ice albedo

Ice mechanical redistribution (sea ice strength)

Coupling – especially how the momentum flux is transfer from atmosphere to the sea ice

Ocean dynamics

Time steps in both ice and ocean models

30-year long runs. 1978-2007

Five 30-year tests are finished and another three are currently running.H_NC2_AL0_ST0_CP0_D0_T0 – Control run

All default values; albedo type= constant

H_NC2_AL1_ST0_CP0_D0_T0

Albedo type = default (ahmax = 0.5m) - albedo is constant above this thickness

H_NC2_AL2_ST0_CP0_D0_T0

Albedo type = default (ahmax = 0.5m) - albedo is constant above this thickness ; shortwave='dEdd’

H_NC2_AL3_ST1_CP0_D0_T0

Albedo type = default (ahmax = 0.3m) - albedo is constant above this thickness ; Cf=5.6

H_NC2_AL4_ST1_CP0_D0_T0

Albedo type = default (ahmax = 0.1m) - albedo is constant above this thickness ; shortwave=’default’; Cf=5.6

AL0 and AL1All default values; albedo type= constant; albedo type = default (ahmax = 0.5m)

AL0 and AL1All default values; albedo type= constant; albedo type = default (ahmax = 0.5m)

AL1 and AL2albedo type = default (ahmax = 0.5m); Albedo type = default (ahmax = 0.5m) ;

shortwave='dEdd’

AL1 and AL2albedo type = default (ahmax = 0.5m); Albedo type = default (ahmax = 0.5m) ;

shortwave='dEdd’

AL3Albedo type = default (ahmax = 0.3m) - albedo is constant above this thickness ; Cf=5.6

AL0, AL1 and AL4albedo type= constant; albedo type = default (ahmax = 0.5m); Albedo type = default (ahmax =

0.1m) ; shortwave='default’, Cf=5.6

Al1 and AL4albedo type = default (ahmax = 0.5m); Albedo type = default (ahmax = 0.1m) ;

shortwave='default’, Cf=5.6

Some conclusionsDefault values of the model settings give not enough sea ice in the results.

2007 ice extent minima was reproduced correctly with H_NC2_AL1_ST0_CP0_D0_T0 experiment.

We still have not get the proper sea ice thickness distribution.

The default ahmax=0.5 m is probably too high; some more tests are needed e.g. with R_ice : tuning parameter for sea ice albedo from Delta-Eddington shortwave.

Plan for the next six months:

Include the volume transport from Atlantic to Pacific side in fully coupled case.

Include and test 2km resolution version of the RASM with at least H comset.

Performed more tuning tests to get acceptable results.

Compare tuning results with measurement at least with RGPS measurements.

AL3Albedo type = default (ahmax = 0.3m) - albedo is constant above this thickness ;

shortwave='dEdd’; Cf=5.6