# What is the difference between variable freshwater ice to ocn (coupler) and freshwater ice to ocn

#### qzg18@psu_edu

##### Member
Hi!
I would like to analyze the freshwater flux from sea ice to ocean in the 1850 control run and I found two related variables -- fresh_ai and fresh, which stand for freshwater ice to ocn (coupler) and freshwater ice to ocn.
Does anyone know about the difference between these two variables?
The patterns of these two variables are similar but the magnitude is not. (See attached ncview for the two variables at the same time step.)

Thanks a lot for any information, suggestions, discussions!

#### dbailey

##### CSEG and Liaisons
Staff member
This is how the multiple categories are merged together to send to the coupler:

fresh = sum(freshn(n)*aicen(n)) / aicen(n) where n is over the subgridscale categories and is divided by aice to get a weighted average flux

fresh_ai = sum(freshn(n)*aicen(n)) where n is over the subgridscale categories and is the actual internal sea ice fresh water flux

In short fresh_ai = fresh*aice.

#### qzg18@psu_edu

##### Member
This is how the multiple categories are merged together to send to the coupler:

fresh = sum(freshn(n)*aicen(n)) / aicen(n) where n is over the subgridscale categories and is divided by aice to get a weighted average flux

fresh_ai = sum(freshn(n)*aicen(n)) where n is over the subgridscale categories and is the actual internal sea ice fresh water flux

In short fresh_ai = fresh*aice.

Hello there!

Thanks a lot for your reply! May I ask a following question? Are there any documents that stores these detailed calculation for different variables? I looked up several times but I only found some very brief introduction of these variables. Thanks a lot again!

#### dbailey

##### CSEG and Liaisons
Staff member
I would recommend the CICE reference manual.

#### qzg18@psu_edu

##### Member
I would recommend the CICE reference manual.

Got it! Thanks a lot!