Opened 7 years ago

Closed 6 years ago

#1055 closed help (fixed)

Sea ice concentration convention in UM7.3

Reported by: aq218 Owned by: willie
Component: UM Model Keywords: sea ice concentration land fraction convention
Cc: Platform: HECToR
UM Version: 7.3


Sorry for this probably trivial question, but I didn't find a definitive answer elsewhere.

I would like what is the convention of the variable "sea ice concentration": Is it the fraction of the total grid box, or the fraction of the sea area (which is already a fraction of the total grid box).

For example, let's say I have a 0.5 of land in a grid box and a sea ice concentration of 0.5. Does it mean that all the sea is ice-covered? Or does it mean that 50% of the sea is ice covered (resulting in a 25% of the total grid box covered by ice)?

Many thanks in advance for your help!

Change History (3)

comment:1 Changed 7 years ago by willie

  • Owner changed from um_support to willie
  • Status changed from new to accepted

Hi Aurelien,

The sea ice model is described in UMDP 45 which can be found at



comment:2 Changed 7 years ago by aq218

Thank you for your reply Willie.

From the manual, however, I think there is no definitive answer to my question. The manual indeed describes well the sea ice model, but does not explicitly mention the treatment of the land fraction. One could guess something reading between the lines, but I would like to have a stronger statement than a guess.

Many thanks,

comment:3 Changed 6 years ago by willie

  • Resolution set to fixed
  • Status changed from accepted to closed
Note: See TracTickets for help on using tickets.