Table 1.

Fields required for articulating emission scaling rules in DESID.

Field Name	Description
Region label	The region label identifies the region over which the rule is to be applied. The keyword EVERYWHERE applies the rule to all grid cells.
Stream label	The stream label identifies the emission streams for which the rule is to be applied. These labels are defined for offline gridded and point sources in the CMAQ runscript. Online emission streams use keywords including BIOG (biogenic vapors), MGEM (marine gas), LTNG (lightning NO), WBDUST (wind-blown dust), and SEASPRAY (sea spray aerosol). The keyword ALL applies the rule to all streams, including online streams.
Emission variable	The emission variable identifies the variable from the emission stream file or online module that emissions should be mapped from. The keyword ALL may be used to apply the rule to all previously mapped variables.
CMAQ species	CMAQ species identifies the variable within CMAQ that the rule should be applied to. The keyword ALL may be used to apply the rule to all previously mapped Species.
Phase/Mode	Phase/Mode is used to distinguish gas or aerosol calculations. If the CMAQ variable is a gas, this field should be set to GAS; if it is an aerosol, this field should indicate the desired aerosol mode (e.g., COARSE, FINE, or other user-defined options) or use the keyword AERO to apply the rule to the entire distribution.
Scale factor	The scale factor is a real-valued number applied for scaling calculations.
Basis	Basis determines whether mass or moles are conserved during conversion from gas to particle emission rates or vice versa. The keyword MASS conserves mass, MOLE conserves moles, and UNIT performs no conversions.
Op	Op determines the operation for each rule to apply: “a” adds the rule to the existing instruction set and could also modify an existing scale factor, “m” finds existing instructions matching this rule’s features (i.e., emission variable names, model species, and stream labels) and multiplies their existing scale factors by this rule’s scale factor, “o” finds existing instructions matching this rule’s features and overwrites their scale factors with this rule’s scale factor.