Nitrogen dioxide is a key atmospheric pollutant affecting air quality, climate, and the biosphere. It mainly originates from human activities like fossil fuel combustion in vehicles and power plants, but also from natural occurrences such as lightning and wildfires. Recognized for producing smog and respiratory issues, nitrogen dioxide's accurate detection is crucial for environmental assessment and pollution reduction strategies.
Satellites have traditionally mapped nitrogen dioxide since the 1990s, with Copernicus Sentinel-5P being a prominent example. However, their coarse resolution limited the ability to pinpoint specific pollution sources, such as individual power plants, as they often averaged many observations. Recent advances have challenged this limitation, enabling precise detection of nitrogen dioxide emissions.
In a groundbreaking study, researchers leveraged the capabilities of Copernicus Sentinel-2 and US Landsat satellites to detect nitrogen dioxide plumes from power plants. Sentinel-2, originally intended for high-resolution Earth imagery to monitor land and natural resources, now demonstrates remarkable proficiency in identifying air pollution, despite its primary focus on land use and water bodies.
The study, focusing on power plants in Saudi Arabia and the USA, demonstrated Sentinel-2’s enhanced spatial resolution in detecting nitrogen dioxide plumes. By using visible and near-infrared bands, researchers identified emissions from specific sources like power plants. This allowed for detailed emission rate estimations at sites such as the Riyadh power plant in Saudi Arabia and a facility in Wyoming, USA. Notably, the study highlighted seasonal variations in emissions, with significant peaks during the summer due to increased air conditioning usage.
Lead researcher Daniel Varon noted the unexpected utility of Sentinel-2 for pinpointing nitrogen dioxide sources in densely populated areas where traditional satellites struggle. This success not only extends the application of Sentinel-2 but also presents a new frontier in air quality monitoring, especially valuable in regions lacking conventional monitoring systems.
Additionally, Sentinel-2 is part of Copernicus, Europe’s environmental monitoring program. Alongside its twin satellites Sentinel-2A and Sentinel-2B, launched in 2015 and 2017, respectively, Sentinel-2C is slated for launch on September 4, 2024. These satellites provide critical optical imagery across 13 spectral bands, useful for diverse environmental monitoring tasks, from land use analysis to natural disaster management.
Utilizing Sentinel-2 and Landsat satellites for detecting nitrogen dioxide emissions paves the way for enhanced environmental monitoring. It provides researchers and policymakers with valuable insights into pollution trends, aiding the development of more effective air quality improvement strategies, thus protecting public health and the environment.
