| Abbreviation | Definition |
|---|---|
| ASDAR | Aircraft-to-Satellite Data Relay System |
| ASDIC | Anti Submarine Detection Investigating Committee |
| ASEAMS | Association of South-East Asian Marine Scientists |
| ASEAN | Association of South-East Asian Nations |
| ASFA | Aquatic Sciences and Fisheries Abstracts |
| ASFIS | Aquatic Sciences and Fisheries Information System |
| ASG | Administrative Support Group |
| ASGPI | Association of Sea Grant Program Institutes |
| ASHES | Axial Seamount Hydrothermal Emissions Study |
| ASHOE | Airborne Southern Hemisphere Ozone Expedition |
| ASL | Above Sea Level |
| ASL | Atmospheric Surface Layer |
| ASLO | Association for the Sciences of Limnology and Oceanography |
| ASMC | ASEAN Specialized Meteorological Centre |
| ASMD | Atmospheric Sciences Modeling Division |
| ASOB | A Sea Of Blue |
| ASP | Antarctic Sleep Program |
| ASPEI | Association of South-Pacific Environmental Institutions |
| ASPIRE | Antarctic Science and Policy Interdisciplinary Research Education |
| ASPRS | American Society for Photogrammetry and Remote Sensing |