Monitoring Pollution Hourly from Space: Preparing for the TEMPO mission

Monitoring Pollution Hourly from Space: Preparing for the TEMPO mission

Remote sensing using spaceborne instruments provides valuable information on the evolution of atmospheric trace gases and atmospheric pollutants. In early 2022, the launch of the geostationary Tropospheric Emissions: Monitoring of Pollution (TEMPO) mission will usher in unprecedented coverage of air quality over North America with hourly measurements available with a spatial resolution of 2.1 km x 4.7 km. Since current spaceborne instruments only provide one overpass over a given location each day, these observations are essential for monitoring the diurnal evolution of trace gases and atmospheric pollutants, and understanding their subsequent role on air quality and public health.

NASA SPoRT has begun working with the TEMPO Science Team to develop synthetic TEMPO data products to use in pre-launch activities to prepare the air quality and public health communities for TEMPO capabilities. The NASA SPoRT Center is generating a long-term archive of synthetic TEMPO Level 2 data products from the global high-resolution Goddard Earth Observing System-5 (GEOS-5) Nature Run with full chemistry (GEOS-5 NR-Chem), operated by the NASA Global Modeling Assimilation Office (GMAO). Using proxy data in pre-launch activities can help accelerate the use of TEMPO data once the mission is calibrated in orbit, and can even help identify future problems and determine solutions.

Below are two examples demonstrating the capabilities of the TEMPO mission. First, Fig. 1 provides a comparison of nitrogen dioxide (NO2) concentration over the state of Alabama between the TEMPO proxy data (left) and the Ozone Measuring Instrument (OMI; currently aboard NASA’s Aura satellite, right).

Fig. 1. Left: TEMPO proxy data, valid at 1417 UTC. Right: OMI data, valid at 1900 UTC. Data applies for September 7, 2013.

The TEMPO proxy data show a much higher spatial resolution than the OMI data, capturing higher magnitude in NO2 concentrations overall (brighter yellow colors in left image) and a stronger gradient in NO2, in particular across north-central Alabama. While OMI provides a coarse, broad distribution in NO2 concentration, the TEMPO proxy data provide detail down to the sub-urban scale, capturing a local maximum corresponding to the Alabama Power Gaston Plant (red dot near center of left image).

If TEMPO data are considered only at the county level, differences in NO2 concentration are still visible between counties (Fig 2, below). Although the emission from the Alabama Power Gaston Plant is no longer apparent, improved spatial information is still provided as compared to OMI.

Fig 2. Left: TEMPO proxy data averaged to the county level, valid at 1417 UTC. Right: OMI data, valid at 1900 UTC. Data applies for September 7, 2013.

More information about the TEMPO mission can be found here.