The Sentinel-5 Precursor (Sentinel-5P) is a satellite system launched in October 2017 after a three-year delay. Part of the European Union’s Copernicus Program, Sentinel-5P focuses on collecting pollution data. It follows the earlier Sentinel-1 to Sentinel-3 missions.
A key instrument onboard is the TROPOspheric Monitoring Instrument (Tropomi). Tropomi monitors visible, ultraviolet, near, and shortwave infrared spectrums to measure ozone, methane, carbon monoxide, sulfur dioxide, and other pollutants in the atmosphere. [1] This makes Sentinel-5P one of the first satellites to provide high-resolution pollution monitoring, enabling daily and even hourly data collection.
Mapping air pollution in real-time
Air quality—not just greenhouse gases—is a growing concern for states and cities. Sentinel-5P arrives at a crucial time, offering more accurate daily pollution reporting. This data will likely be integrated into weather forecasts, particularly over regions like Europe.
Other parts of the world will also benefit as more countries and organizations adopt this program.
The collected data is free and open to the public. Scientists, governments, NGOs, and businesses can use it to monitor pollution and develop strategies for reduction. The Copernicus Atmosphere Monitoring Service (CAMS) helps interpret this complex data into formats that are machine-readable and user-friendly, making the information accessible to a broader audience. [2]
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Advancing atmospheric monitoring
Unlike earlier Sentinel missions focused on weather, land, and oceans, Sentinel-5P is dedicated to atmospheric monitoring. The satellite follows a low orbit and uses advanced techniques to improve pollution data quality.
For pollutants like carbon monoxide, previous data relied on incomplete, sparse ground-based sensors. Sentinel-5P offers high temporal (time-based) and spatial resolution, with hourly updates. This precision allows for detailed air quality monitoring in sensitive regions where humidity and temperature fluctuations impact pollution levels. [3]
Critically, the data will have temporal and spatial resolution divisible by hourly data. This allows pollution monitoring to be far more precise on changing air quality in regions that are particularly sensitive to environmental changes such as humidity and temperature fluctuations that can affect the degree to which pollution concentration changes.[4] Large- and small-scale events, including forest fires and local weather fluctuation, are qualities that could be captured by the data and applied in forecast models.[5]
Monitoring ozone and ultraviolet light
Other sets of data retrieved include ozone profile and tropospheric ozone column data that can monitor.[6] This will include daily monitoring of global ozone levels, providing a much greater temporal resolution of fluctuations to atmospheric ozone than previous monitoring. Related to ozone levels, surface ultraviolet light will also be monitoring to allow a day-to-day global and local perspective on ultraviolet damage caused by the sun.
Testing and the future of Sentinel satellites
In late October 2017, the satellite was undergoing preliminary testing on its various instruments. These are being prepared and tested before scientifically useful data are collected and released. While Sentinel 5-p will soon be providing new data, the larger Copernicus Program will offer many more Sentinel satellites to provide the most comprehensive earth observation program than what has been done previously.[7] There are threats to the wider program, including budgetary constraints, but the need for earth observation relatively to a rapidly changing planet has meant that so far governments in the European Union have seen this as a wider benefit than cost.
References
[1] For more on the background to the satellite system, see: https://earth.esa.int/web/guest/missions/esa-eo-missions/sentinel-5p
[2] For a recent article discussing the benefits of the system, see: http://www.esa.int/Our_Activities/Observing_the_Earth/Copernicus/Sentinel-5P/Ready_to_reap_the_benefits_from_Copernicus_Sentinel-5P.
[3] For more on monitoring carbon monoxide using the Sentinel-5 mission, see: Dekker, I., S. Houweling, I. Aben, T. Roeckmann, and M. Krol (2017), Quantification of point sources of carbon monoxide using satellite measurements, vol. 19, p. 13167. [online] Available from: http://adsabs.harvard.edu/abs/2017EGUGA..1913167D.
[4] For more on the temporal quality of the data and its applicability, see: Zoogman, P., Liu, X., Suleiman, R.M., Pennington, W.F., et al. (2017) Tropospheric emissions: Monitoring of pollution (TEMPO). Journal of Quantitative Spectroscopy and Radiative Transfer. [Online] 186, 17–39. Available from: doi:10.1016/j.jqsrt.2016.05.008.
[5] For more on events that could be captured by Sentinel-5p, see: Abida, R., Attié, J.-L., El Amraoui, L., Ricaud, P., et al. (2017) Impact of spaceborne carbon monoxide observations from the S-5P platform on tropospheric composition analyses and forecasts. Atmospheric Chemistry and Physics. [Online] 17 (2), 1081–1103. Available from: doi:10.5194/acp-17-1081-2017.
[6] For more on ozone monitoring, see: https://sentinel.esa.int/documents/247904/2474724/Sentinel-5P-Science-Validation-Implementation-Plan
[7] For information on different Sentinel satellites, see: http://www.copernicus.eu/main/sentinels