What is nitrous oxide? 

Nitrous oxide (N₂O) is a significant greenhouse gas produced from both natural and anthropogenic sources. Soil- and ocean-dwelling bacteria are major natural sources of N₂O, producing the gas while breaking down other nitrogen compounds. Artificial fertilizers can increase the activity of these bacteria, but nitrous oxide can also be directly produced as a byproduct of fuel combustion, industrial processes, and waste processing.

While N₂O is scarcer than other greenhouse gases, such as carbon dioxide (CO₂), it absorbs infrared radiation at specific wavelengths that CO₂ does not. Although the National Ocean and Atmospheric Administration (NOAA) estimates that the atmospheric concentration of N₂O is approximately one-thousandth that of CO₂, the U.S. Environmental Protection Agency (EPA) estimates that N₂O has more than 200 times the warming potential of CO₂ per pound. Despite its relative rarity, N₂O is thus a major greenhouse gas.

How do we monitor nitrous oxide?

Several NASA missions measure trace gases like nitrous oxide that can have substantial impacts on our atmosphere despite their scarcity. For example, the Microwave Limb Sounder (MLS) on the Aura satellite measures thermal emissions from the edge of Earth’s atmosphere that can be used to extrapolate concentrations of trace gases. The Uncrewed Aircraft Systems (UAS) Chromatograph for Atmospheric Trace Species (UCATS) is an instrument suite that provides rapid and highly precise in situ trace gas measurements from aircraft. In the recent past, instruments like the Tropospheric Emission Spectrometer (TES) were also used to monitor nitrous oxide, adding to a record of atmospheric trace gases that now extends back more than two decades. 

What can we do with nitrous oxide data? 

NASA has been providing near-real-time (NRT) estimates of vertical N₂O atmospheric profiles since 2021, helping scientists monitor the balance of nitrogen in the atmosphere and study the role of nitrous oxide in regulating Earth’s temperature and climate. NRT nitrous oxide data can be accessed through NASA Earthdata.