The Tropospheric Emissions: Monitoring of Pollution (TEMPO) instrument is a grating spectrometer, sensitive to ultraviolet and visible wavelengths of light with a spectral range of 290-490 and 540-740 nm and 0.6 nm spectral resolution. The TEMPO instrument is in geostationary orbit at 91˚ W longitude (about 22,000 miles above Earth's equator). This allows TEMPO to maintain a continuous view of North America so that the instrument's light-collecting mirror can make a complete East-to-West scan of the field of regard hourly during daylight hours. By measuring sunlight reflected and scattered from the Earth's surface and atmosphere back to the instrument's detectors, TEMPO's ultraviolet and visible light sensors provide measurements of ozone, nitrogen dioxide, formaldehyde, aerosols, and other constituents important for understanding air quality and the chemistry of Earth's atmosphere.

The primary mission objective of TEMPO is to improve our understanding of air quality and its impacts. By providing near real-time data and comprehensive atmospheric composition measurements, TEMPO helps advance knowledge of the Earth system and improve air quality forecasting. These data also aid in quantifying how air quality affects vegetation, agriculture, and human health.

TEMPO was built by Ball Aerospace & Technologies Corp. (now BAE Systems Inc.) and launched on April 7, 2023, on a SpaceX Falcon 9 rocket from Florida's Cape Canaveral Space Force Station. TEMPO is attached to the Earth-facing side of the commercial Maxar Technologies-manufactured communications satellite Intelsat 40e. The instrument beamed back its first Earth images on August 2, 2023. The TEMPO mission is a collaboration between the Smithsonian Astrophysical Observatory and NASA, supported by the NASA Science Mission Directorate. TEMPO serves as the North American component of an international geostationary constellation for air quality measurements.

TEMPO Version 04 (V04) Level 1, 2, and 3 standard data products began production on September 17, 2025. The previous TEMPO data version (V03) was released publicly on May 24, 2024, and cover the time period from August 2, 2023 to September 16, 2025. All observations since the beginning of the mission are being reprocessed with V04 algorithms, with V04 products becoming publicly available as they are reprocessed. TEMPO V03 products reached PROVISIONAL validation status as of December 9, 2024 per the TEMPO Validation plan.

TEMPO Near Real-Time (NRT) Version 02 (V02) Level 1, 2, and 3 data products were released publicly on September 17, 2025. TEMPO NRT data are produced using a fast version of the TEMPO baseline retrieval processor. The NRT processing optimizes radiance calibration, image navigation and registration, and cloud and trace gas retrievals for rapid processing, while ensuring that product quality is sufficient for most NRT applications. The NRT data are available on a 14-day rolling period.

User Guides and Algorithm Theoretical Basis Documents (ATBDs) describing the data products in the V04 release are listed below. The TEMPO ozone profile ATBD is still being finalized and is available upon request by contacting the ASDC at larc-dl-asdc-tempo@mail.nasa.gov.

For inquiries about this TEMPO data release, please post/view questions on Earthdata Forum.

Data Services

• Worldview
• L2 Subsetting and aggregation ReadMe documents
• Esri Living Atlas of the World
• Earthdata GIS

More information about TEMPO and the services the ASDC provides may be found in the TEMPO storymap

Data User Guides and Technical Documents

Data User Guides

• Level 1 User Guide
• Near Real-Time Data Products User Guide and ATBD Supplement
• O3Prof Level 2 & 3 User Guide
• O3Tot Level 2 & 3 User Guide
• Trace Gas (NO2 & HCHO) & Cloud Level 2 & 3 User Guide

Algorithm Theoretical Basis Documents (ATBD)

• Algorithm Theoretical Basis for Version 3 TEMPO Level 0-1 Processor (ATBD)
• Algorithm Theoretical Basis for Version 3 TEMPO O2-O2 Cloud Product (ATBD)
• TEMPO Formaldehyde Retrieval Algorithm Theoretical Basis Document (ATBD)
• TEMPO Nitrogen Dioxide Retrieval Algorithm Theoretical Basis Document (ATBD)

Technical Documents

• O3Tot Level 2 & 3 Algorithm Description
• Operations Log
• Commissioning Log
• Validation Plan
• Validation Report (baseline draft)
• For the current week's predicted overpass times at selected sites, see OverPass