MAM/CARMA interface to MOIST by means of AERO_ACI is currently broken

[amdasilva]

The Problem

As a side effect of the initial GOGART2G implementation, the AERO_ACI state (whgich is still exported by MAM and CARMA) has been removed from the EXPORT of GEOSchem_GridComp, and MOIST has been modified so as to retrieve a generic AERO state (the onloy one exported by GOCART2G). As a consequence, MAM and CARMA can no longer be aerosol providers to MOIST.

The Fix

Restore AERO_ACI as one of the exports of GEOSchem_GridComp and modify MOIST accordingly. Since GOCART only exports a single AERO state (which provides callbacks for RADIATION, MOIST amd GAAS), a device is needed to add it to the export of GEOSchem_GridComp with a diffefrent name: AERO_ACI. Such implementation requires a small patch of the ESMF allowing states to be aliased. A request has been made to the ESMF core team by Tom and Atanas.

As we imnplement this, it would be desirable to allow multiple AERO_PROVIDERS:

AERO_PROVIDER_TO_RAD
AERO_PROVIDER_TO_MOIST
AERO_PROVIDER_TO_GAAS

Under normal circunstances these would specify the same AERO_PROVIDER. However, for science applciations one may want to mix and match, e.g., having GOCART2G.data being the AERO_PROVIDER_TO_RAD, while MAM serving as the AERO_PROVIDER_TO_MOIST.

Depending on when this is implemented, it may need to harmonized with the new PROVIDE_SERVICE/REQUIRE_SERVICE capability that is in the works.