Add Export of evaporative flux for use by ocean

[DeniseWorthen]

Description

MOM6 requires the evaporative flux from the ATM. Currently, the latent heat flux from ATM is converted in CMEPS to provide the required field. It would be better if ATM would provide the evaporative flux directly.

See NOAA-EMC/CMEPS#93

Solution

In atmos_model, add a conversion of the latent heat flux (dqsfc_cpl) to provide a new output for the evaporative flux. The existing latent heat flux export will remain unchanged.

Alternatives

If applicable, add a description of any alternative solutions or features you've considered.

Testing:

1. Have you tested the code changes? On what platforms?
2. Have you run regression test in ufs-weather-model or ufs-s2s-model with code changes?

• Will the baseline results change?
• If yes, please give brief explanation of your code updates on the regression test.

Testing has been done in the coupled RTs. Baselines change because of round-off level differences for the evaporative flux in the first coupling loop. Full testing will be reported in the associated UFS PR.

Dependent PRs:

Directly reference any issues or PRs in this or other repositories that this is related to, and describe how they are related. Example:

• required to support noaa-emc/GFDL_atmos_cubed_sphere/issues/<issue_number>
• ncar/ccpp-physics/pull/<pr_number>
• associated ufs-weather-model/pull/<pr_number>