| Abbreviation | Definition |
|---|---|
| CFRB | Cape Fear River Basin |
| CFS | Cubic Feet per Second |
| CG | Cloud To Ground |
| CGLAS | Center for Great Lakes Aquatic Sciences (University of Michigan; Ann Arbor, MI) |
| CGMS | Coordination on Geostationary Meteorological Satellites |
| CGMW | Commission for the Geological Map of the World |
| CHARM | Coupled Hydrosphere- Atmosphere Research Model |
| CIAD | Climate Impact Assessment Division |
| CIBL | Convective Internal Boundary Layer |
| CICA | Certificate of Inspection of Crew Accommodation |
| CICAR | Cooperative Investigation of the Caribbean and Adjacent Regions |
| CICOR | Cooperative Institute for Climate and Ocean Research |
| CICS | Cooperative Institute for Climate Studies |
| CIDCO | Centre Interdisciplinaire de Développement en Cartographie des Océans |
| CIEA | Committee on International Ocean Affairs |
| CIEP | Coastal Energy Impact Program |
| CIESIN | Consortium for International Earth Science Information Network |
| CIFAR | Cooperative Institute for Arctic Research |
| CILER | Cooperative Institute for Limnology and Ecosystems Research |
| CIMAS | Cooperative Institute for Marine and Atmospheric Studies |