icb speed limit and speeding ticket

[mathiot]

Context

In the icb module, we can enforce the icb speed limit via rn_speed_limit and issue a speeding ticket if needed. Scaling down the icb speed at the end of icb_accel does not have any effect and the collection of speeding ticket is hard to interpret (all domains report the same number of speeding tickets, even if no icb on the domain).

Analysis and recommandation

• Icb speed is not an output of icb_accel, so scaling the speeding down according to the cfl will not have any effect on the simulation. Probably we should scale down the velocity and recompute the acceleration accordingly.
• About the icb report, I suggest to remove the mpp_sum on nspeeding_ticket in icb_dia. Like this, every process will show the number of speeding ticket on its domain.
• probably additional information on what cause the speeding ticket could be useful (is it the atmo, the oce, the ice …)

It affects the trunk and v4.

[davestorkey]

In 14268:

UKMO branch to implement Pierre's version of the iceberg speed limiter (ticket #2581).