PM25_OC_AVG in EQUATES CMAQ output

EQUATES
1

Hi,

I’d like to ask what the PM25_OC_AVG variable in EQUATES CMAQ output files represent. Does it represent pure carbon mass or the total organic matters mass ( including mass of oxygen, hydrogen, etc.)? Is PM2.5_avg the sum of PM25_OC_AVG (OC or OM?), PM25_EC_AVG, PM25_NO3_AVG, PM25_SO4_AVG, PM25_NH4_AVG and others (e.g., sea salt, dust)?

Thanks,
Huazhen

2

Hello Huazhen,

PM25_OC_AVG represents just the carbon mass, not the total organic matter mass. PM2.5_AVG is the total PM2.5 mass, including the species you listed that are included in these files as well as others such as crustal elements, sea salt, and the non-carbonaceous portion of total organic matter mass. The species included in these files are described in Table 7 of the EQUATES data dictionary and, as mentioned in that dictionary, the exact definition of how each species is calculated from the raw CMAQ output variables is documented in this file.

1 Like