| Abbreviation | Definition |
|---|---|
| ASSP | Aerosol Scattering Spectrometer Probe |
| ASSP | Approved Species-specific Protocol |
| ASTC | Association of Science and Technology Centers |
| ASTEX | Atlantic Stratocumulus Transition EXperiment |
| ASTINFO | Regional Network for the Exchange of Information and Experience in Science and Technology in Asia and the Pacific |
| ASWP | Atlantic Salmon Watch Program |
| ATA | American Tunaboat Association |
| ATAD | Atmospheric Transport And Dispersion |
| ATC | Air Traffic Control |
| ATCP | Antarctic Treaty Consultative Parties |
| ATCSCC | ATC Systems Command Center |
| ATDD | Atmospheric Turbulence and Diffusion Division |
| ATL | Atlantic |
| ATLAS | Aquatic and Terrestrial Load of Anthropogenic Substances |
| ATLAS | Atmospheric Laboratory for Applications and Science |
| ATLAS | Autonomous Temperature Line Acquisition System |
| ATMES | Atmospheric Transport Model Evaluation Study |
| ATMS | Advanced Traffic Management System |
| ATOC | Acoustic Thermography of Ocean Climate |
| ATOP | Advanced Technologies for Oceanic Procedures |