Does EE Equilibrium Temp (CE-QUAL-W2) method include ice cover process

Hello All,
We are conducting thermal modeling with EE.

I know orginal EFDC code did not include ice cover processes, which would result in wrong results (negative water temperature) during winter for northern waterbody. And we tried Equilibrium Temp (CE-QUAL-W2) thermal sub-model and get non-negative water temperature during winter. I learned CE-QUAL-W2 includes ice cover processes.

So, my questions are:
- Does EE include ice cover process within its enhancement to EFDC code? Hopefully it is a yes,
- If EE includes ice cover processes, can I get ice thickness from EE?
- Equilibrium Temp is for surface heat exchange in CE. Does this sub-model in EE also use the bed heat exchange in CE or just the surface part?

I do not find any information in EFDC or EE manual, so not sure how many processes in CE are incorporated in EE?
Thanks for your reply


The WQ submodel, CEQUAL-W2, includes an equilibrium temperature calculation module, and a separate module for ice formation and melting. As of release EE7.0 the EFDC_DSI code includes the former but not the latter.

While EFDC_DSI has the ability to simulate the effect of ice, this is not supported directly by EE7 at this point. The user must manually specify the ice effects and EE does not allow the user to pre- and post- process this. As it is user specified it should be understood that there is no linkage to the WQ temperature submodel. This means the user specified ice effects will overwrite the CEQUAL W2 equilibrium temperature. Though there are users who use this submodel, the feature is not really supported by DSI at this stage and we can’t provide any detailed guidance. You will need to look at the code to work out how to do it.

The EFDC_Explorer team would like to provide a full ice submodel eventually.