| Abbreviation | Definition |
|---|---|
| A&P | Analysis and Prediction |
| A/OGCM | Coupled Atmosphere/Ocean General Circulation Model |
| AA | Assistant Administrator |
| AAAG | Atlantic Arc Aquaculture Group |
| AAAS | American Association for the Advancement of Science |
| AABW | AntArctic Bottom Water |
| AAIW | Antarctic Intermediate Water |
| AAM | Atmospheric Angular Momentum |
| AAOE | Airborne Antarctic Ozone Experiment |
| AAOT | Acqua Alta Oceanographic Tower |
| AAPB | Aerobic Anoxyenic Phototrophic Bacteria |
| AARC | Arctic Antarctic Research Center |
| AARI | Arctic and Antarctic Research Institute |
| AARS | Automated Aircraft Reporting System |
| AAS | Advanced Automation System |
| AAS | American Astrophysical Society |
| AASE | Airborne Arctic Stratospheric Expedition |
| AASR | Annual Aquaculture Statistical Report |
| AB | Asymmetric Balance |
| ABISS | Automated Benthic Image Scaling System |