| Abbreviation | Definition |
|---|---|
| PA | Public Affairs |
| PAC | Pacific |
| PAC | PACific Coast |
| PACICOM | Pacific Coastal Marine Productivity |
| PACS | Pan American Climate Studies |
| PACTOP | Pacific Tsunami Observation Program |
| PAGES | Past Global Changes |
| PAH | Polycyclic Aromatic Hydrocarbon |
| PALACE | Profiling Autonomous LAgrangian Circulation Explorer |
| PAMR | Professional Aquarium Maintenance Research |
| PAMR | Professional Aquarium Maintenance & Research |
| PAN | PeroxyAcetyl Nitrate |
| PAO | Pierre Auger Observatory |
| PASFIS | Philippines Aquatic Sciences and Fisheries Information System |
| PATHS | Pacific Transport of Heat and Salt |
| PBECS | Pacific Basin Extended Climate Study |
| PBG | Personal Bathymetry Generation |
| PBL | Planetary Boundary Layer |
| PCAST | President's Council of Advisors on Science and Technology |
| PCB | Poly Chlorinated Biphenal |