| Abbreviation | Definition |
|---|---|
| RSHMI | Russian Hydrometeorological Institute |
| RSL | Rising Sea Level |
| RSMAS | Rosenstiel School of Marine and Atmospheric Science |
| RSMC | Regional Specialized Meteorological Center |
| RSMIS | Real Estate and Space Management Information System |
| RSR | Rotating Shadowband Radiometer |
| RSS | Remote Sensing Science |
| RTE | Repairs-To-Extend |
| RUGGIERO | Ranging Under Ground Gearing In Entry on Remote Ocean |
| RUW | Remaining Usable Water |
| RV | Research Vessel |
| RVOC | Research Vessel Operators Council |
| RVR | River |
| RW | Right Whale |
| RW | Rough Water |
| RWI | Raw Water Intake |
| RWI | Rural Watershed Initiative |
| S | Smooth |
| S3T | Sequentially Sampling Sediment Trap |
| SA | Simple- Adjoint |