Description: The Interagency Monitoring of Protected Visual Environments (IMPROVE) consists of air quality data from Class I areas that include national parks and wilderness areas where visibility is deemed an important attribute. This monitoring program is an interagency effort with the U.S. Environmental Protection Agency (USEPA) and the U.S. Department of the Interior (USDOI), including the U.S. Forest Service, U.S. Fish and Wildlife Service, and the Bureau of Land Management. The IMPROVE fine particle network collects PM2.5 and PM10 samples over a twenty four hour period every Monday and Friday using IMPROVE samplers. The network consists of over 110 monitoring sites, located in Class I ("Clean Air") areas, and has been in operation since 3/88. The PM samples are analyzed for PM2.5 mass and its elemental constituents, organics, ions, light absorption and PM10 mass.
| Compound | IMPROVE Species | CMAQ Mapping | REMSAD Mapping |
| SO4 | SO4 | ASO4J + ASO4I | GSO4 + ASO4 |
| NO3 | NO3 | ANO3J + ANO3I | PNO3 |
| OC | 1.4*(OC1+OC2+OC3+OC4+OP) | AORGAJ+AORGAI+AORGPAJ+AORGPAI+AORGBJ+AORGBI | SOA+POA |
| EC | EC1+EC2+EC3-OP | AECJ+AECI | PEC |
| SOIL | 2.2*A1 + 2.49*Si + 1.63*Ca + 2.42*Fe + 1.94*Ti | A25I + A25J | PMFINE |
| CM | MT - FM | ACORS + ASEAS + ASOIL | PMCOARS |
| PM25a | FM | 1.375(ASO4J + ASO4I) + 1.29*(ANO3J + ANO3I) + AORGAJ + AORGAI + AORGPAJ + AORGPAI + AORGBJ + AORGBI + AECJ + AECI + A24J + A25I | 1.375*(GSO4 + ASO4) + 1.29*PNO3 + SOA + POA + PEC + PMFINE |
| RCFM | 1.375*SO4 + 1.29*NO3 + EC + OC + SOIL | Same for PM25 | Same for PM25 |
| PM10 | MT | 1.375*(ASO4J + ASO4I) + 1.29*(ANO3J + ANO3I) + AORGAJ + AORGAI + AORGPAJ + AORGPAI + AORGBJ + AORGBI + AECJ + AECI + A25J + A25I + ACORS + ASEAS + ASOIL | 1.375*(GSO4 + ASO4) + 1.29*PNO3 + SOA + POA + PEC + PMFINE + PMCOARS |
| BEXT_Recon (1/Mm) | 10b + 3*f(RH)c(1,375*SO4 + 1.29*NO3) + 4*OC + 10*EC + SOIL + 0.6*CM | 10b + 3*f(RH)c[1.375*(ASOFJ + ASO4I) + 1.29*(ANO3J + ANO3I)] + 4*1.4*(AORGAJ + AORGAI + AORGPAJ + AORGPAI + AORGBJ + AORGBI) + 10*(AECJ + AECI) + 1*(A25J + A25I) + 0.6*(ACORS + ASEAS + ASOIL) | 10b + 3*f(RH)c*[1.375*(GS04 + ASO4) + 1.29*(PNO3)] + 4*(SOA + POA) + 10*PEC + 1*PMFINE + 0.6*PMCOARS |