| Abbreviation | Definition |
|---|---|
| LWO | Limited Weather Observation |
| LWS | Low Water Spring |
| LWT | Leaving Water Temperature |
| MA | Meteorological Applications |
| MAB | Man And the Biosphere Program |
| MAC | Mid-Atlantic Cyclone |
| MAD | Magnetic Anomaly Detector |
| MAD | Mid Atlantic Ducati |
| MADER | Management of Atmospheric Data for Evaluation and Research |
| MAESA | Measurements for Assessing the Effects of Stratospheric Aircraft |
| MAFAC | Marine Fisheries Advisory Committee |
| MAFF | Ministry of Agriculture, Fisheries, and Food |
| MAFIS | Malaysian Aquatic Sciences and Fisheries Information System |
| MAGE | Marine Aerosol and Gas Exchange |
| MAMBO | Mediterranean Association of Marine Biological Oceanography |
| MAOA | Panel on Meteorological Aspects of Ocean Affairs |
| MAP | Model Aviculture Program |
| MAPS | Measuring Air Pollution from Space |
| MAPS | Mesoscale Analysis and Prediction System |
| MAR | Mid-Atlantic Ridge |