| Abbreviation | Definition |
|---|---|
| GTR | Government Transportation Request |
| GTS | Global Telecommunication System |
| GUFMEX | Gulf of Mexico |
| GVAP | GEWEX Water Vapor Project |
| GWE | Global Weather Experiment |
| GWI | Greenhouse Warming Index |
| GWP | Global Warming Potential |
| GWPAS | General Work Force Performance Appraisal System |
| GWS | Great White Shark |
| GWT | Great White Trail whale tracking |
| HAB | Harmful Algal Blooms |
| HACCP | Hazard Analysis and Critical Control Point |
| HALOE | Halogen Occultation Experiment |
| HAM | Hydrogeochemical Assessment Model |
| HAPC | Habitat Areas of Particular Concern (NOAA) |
| HAPEX | Hydrological Atmospheric Pilot Experiment |
| HARM | Hazardous Atmospheric Release Model |
| HAT | Highest Astronomical Tide |
| HAZMAT | Hazardous Materials Response and Assessment Division |
| HBOI | Harbor Branch Oceanographic Institution |