| Acronym | Meaning |
 | SEM | System Element Management |
 | SEQUAL | Seasonal Equatorial Atlantic Study |
 | SERI | Solar Energy Research Institute |
 | SERON | Southeastern Regional Oxidant Network Program |
 | SERON | Southeastern Regional Oxidant Network Program |
 | SERP | Strategic Environmental Research Program |
 | SERP | Strategic Environmental Research Program |
 | SERS | STORM Education And Research System |
 | SESAME | Second European Stratospheric Arctic And Mid-Latitude Experiment |
 | SESAME | Severe Environmental Storms And Mesoscale Experiment |
 | SESQUINET | N/A |
 | SESS | Space Environment Support System |
 | SETA | Satellite Electrostatic Triaxial Accelerometer |
 | SFC OR SFC | Surface |
 | SG | Semigeostrophic |
 | SG&A | Sales |
 | SGGE | Second GARP Global Experiment |
 | SGI | Silicon Graphics Inc. |
 | SGML | Standard Generalized Markup Language |
 | SGS | Subgrid Scale |
 | SH | Southern Hemisphere |
 | SHEBA | Surface Heat Budget Of The Arctic Ocean |
 | SHEF | Standard Hydrometeorological Exchange Format |
 | SHF | Super High Frequency |
 | SHF | Super High Frequency |
 | SHIRE | Southern Hemisphere Infrared Experiment |
 | SI | Solar Interiors Section |
 | SI | Systeme International |
 | SIAM | Society For Industrial And Applied Mathematics |
 | SIBIZMIR | Siberian Institute Of Terrestrial Magnetism |
 | SICIMS | Selected Iron Chemical Ionization Mass Spectrometry (or Spectrometer |
 | SID | Sudden Ionospheric Disturbance |
 | SIE | Scale Interation Equipment |
 | SIFE | Second ISLSCP Field Experiment |
 | SIGGRAPH | Special Interest Group On Graphics Of The Association Of Computing Machinery |
 | SIGMA | Software For Interactive Graphics And Model Analysis |
 | SIGMET | Significant Meteorological Information |
 | SIM | Solar Interplanetary Model |
 | SIO | Scripps Institution Of Oceanography |
 | SIPI | Scientists' Institute For Public Information |
 | SIPRI | Stockholm International Peace Research Institute |
 | SIR | Shuttle Imaging Radar |
 | SIR | Spaceborne Imaging Radar |
 | SIRIS | Stratospheric Infrared Interferometer Spectrometer |
 | SIRS | Satellite Infrared Spectrometer |
 | SIRS | Social Issues Resources Services |
 | SISEX | Shuttle Imaging Spectrometer Experiment |
 | SISP | Surface Imaging & Sounding Package |
 | SJVAQS | San Joaquin Valley Air Quality Study |
 | SKE | Specific Kinetic Energy |