| ACR | Anomalous Cosmic Ray |
| ACRIM | Active Cavity Radiometer Irradiance Monitor |
| AMO | Atlantic Multidecadal Oscillation |
| CERN | European Organization for Nuclear Research |
| CME | Coronal mass ejection |
| cosmic ray | Highly energetic atomic nucleus that travels through space at nearly the speed of light |
| Dalton Minima | A period of low solar activity lasting from 1790 to 1830 and named after John Dalton |
| ENSO | El Niño-Southern Oscillation |
| EPP | Energizing precipitating particle |
| Forcing | An externally imposed perturbation in the radiative energy budget of Earth’s climate system. Also called radiative forcing. |
| GCM | Global climate model |
| GCR | Galactic cosmic ray |
| Hadley cell | Atmospheric circulation with rising motion near the equator, poleward flow, and sinking motion in the subtropics |
| Little Ice Age | A cooling period from 1550 to 1850 |
| Maunder Minimum | A period of low solar activity lasting from 1645 to 1715 and named after Edward W. Maunder |
| Milankovitch cycle | Long-term changes in Earth’s orbit that in turn affect its climate over long periods of time |
| NASA | National Aeronautics and Space Administration |
| NRC | National Research Council |
| NSF | National Science Foundation |
| Photosphere | Visible surface of the Sun |
| PREMOS | Precision Monitoring Sensor experiment onboard the PICARD French microsatellite mission |
| QBO | Quasi-biennial oscillation |
| SBUV | Solar backscatter ultraviolet |
| SEP | Solar energetic particle |
| SIM | Spectral Irradiance Monitor |
| SOLSTICE | Solar Stellar Intercomparison Experiment |
| SORCE | Solar Radiation and Climate Experiment |
| SPE | Solar proton event |
| Spörer minimum | A period of low solar activity lasting from 1460 to 1550 and named after Gustav Spörer |
| SSI | Solar spectral irradiance |
| SST | Sea surface temperature |
| TIM | Total Irradiance Monitor |
| TSI | Total solar irradiance |