| Abbreviation | Definition |
|---|---|
| PPMV | Parts Per Million By Volume |
| PPT | Parts Per Trillion |
| PR | PRessure |
| PRAISE | Pacific Regional Aquaculture Information Service for Education |
| PRB | Polar Research Board |
| PRC | Planning Research Corporation |
| PRE-STORM | Preliminary Regional Experiment for STORM |
| PREVENT | Pacific Northwest Regional Visibility Experiment using Natural Tracers |
| PRF | Pulse Repetition Frequency |
| PRL | Polar Research Laboratory |
| PROBE | Pilot Radiation Observation Experiment |
| PROBES | Processes and Resources of the Bering Sea Shelf |
| PROCOPA | Peruvian-German Cooperative Program for Fisheries Investigations |
| PROFS | Program for Regional Observing and Forecasting Services |
| PROMAR | Program on the Promotion of Marine Sciences |
| PROMES | PROnostico a MESoscala |
| PROP | Propeller |
| PROTEUS | Profile Telemetry of Upper Ocean Currents |
| PSA | Pacific Science Association |
| PSA | Precipitation Series Algorithm |