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 + 540-740 nm and 0.6 nm spectral resolution. The TEMPO instrument is attached to the Earth-facing side of a commercial telecommunications satellite (Intelsat 40e) 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 to advance knowledge of the Earth system and the study and forecasting of air quality and aids in quantifying the impact of air quality on 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 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 03 (V03) Level 1, 2, and 3 data have reached PROVISIONAL validation status as of December 9, 2024. Please note that there have been no changes to the TEMPO V03 data files themselves; therefore, if users have already downloaded the TEMPO V03 data (previously labeled as Beta), they do not need to re-download the data. These datasets are at provisional maturity, which means that product performance has been demonstrated through a large but still (seasonally or otherwise) limited number of independent measurements. The analysis is sufficient for limited qualitative determinations of product fitness-for-purpose, and the product is potentially ready for testing by operational users and may be suitable for scientific publication.

User Guides and Algorithm Theoretical Basis Documents (ATBDs) describing the data products in the provisional V03 release are listed below. The Level 1B TEMPO ATBD is still being finalized and is available upon request. To access the Level 1B ATBD, please contact 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
• ArcGIS image service for TEMPO L3 NO2 troposphere beta imagery
• L2 Subsetting and aggregation ReadMe documents

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
• 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 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
• For the current week's predicted overpass times at selected sites, see OverPass