N2O, potent greenhouse gas and ozone depleting substance
Nitrous oxide (N2O) is
- the third most important anthropogenic greenhouse gas, with a radiative forcing potential of 265 to 300 times that of CO2 per mass unit (integrated over 100 years)
- mostly present in the troposphere, with a lifetime of about 120 years
- an ozone depleting substance, when it crosses the tropopause and reaches the stratosphere
Anthropogenic contribution to N2O emissions amounts to about 40%

N2O surface concentration is continuously increasing with time
The surface concentration of nitros oxide increased from a global annual average of 270 ppb (parts per billion) in 1750 to about 338 ppb in 2024.

Nitrous oxide has to be included in climate change mitigation strategies
Reducing N2O emissions can be achieved with adapted agricultural policies (that can also lead to increased crop yields) and improved industrial technology, as demonstrated by the decreasing trend of Europe emissions since the late 1980s (Tian et al., Nature 2020).
Global N2O data obtained from IASI
Our retrieval algorithm is called Nitrous Oxide Profiling from Infrared Radiances (NOPIR) and
- uses the data gathered by the Infrared Atmospheric Sounding Interferometer (IASI) onboard the EUMETSAT Metop satellite series since end 2006.
- exploits the N2O ν3 asymmetric stretch vibration mode around 2200 cm-1 (4.5 µm) - selected spectral micro-windows only minimally affected by absorption from other atmospheric gases
- produces vertical profiles of N2O concentration between the surface and 80hPa, from which a partial column can be calculated.
The first version of the algorithm has been used to produce 10 years of data (2011-2021) from IASI/Metop-A. The validation shows a very small positive bias of NOPIR with respect to reference instruments (NDACC and TCCON), of 1.8 to 4%. That version however showed discontinuities/inconsistencies, due to discontinuities/inconsistencies in the IASI data used as input, which would prevent from calculating trends.
The second version of the algorithm (NOPIR v2.1) has been used to produce 14 years (2007-2021) of data from IASI/Metop-A and 6 years (2019-2025) of data from IASI/Metop-C. Its validation shows even smaller bias against the reference networks, and long-term consistency.
N2O data
Upcoming, with new algorithm version publication.
In the mean time, data can be obtained from the contact below.
Contact: Sophie Vandenbussche
E-mail: sophie (at) vandenbussche (at) aeronomie (dot) be
References
Algorithm
- Vandenbussche, S., Langerock, B., Vigouroux, C., Buschmann, M., Deutscher, N. M., Feist, D. G., García, O., Hannigan, J. W., Hase, F., Kivi, R., Kumps, N., Makarova, M., Millet, D. B., Morino, I., Nagahama, T., Notholt, J., Ohyama, H., Ortega, I., Petri, C., Rettinger, M., Schneider, M., Servais, C. P., Sha, M. K., Shiomi, K., Smale, D., Strong, K., Sussmann, R., Té, Y., Velazco, V. A., Vrekoussis, M., Warneke, T., Wells, K. C., Wunch, D., Zhou, M., and Mazière, M. D.: Nitrous Oxide Profiling from Infrared Radiances (NOPIR): Algorithm Description, Application to 10 Years of IASI Observations and Quality Assessment, 30, 2022, https://doi.org/10.3390/rs14081810
Background
- Canadell, J.G., P.M.S. Monteiro, M.H. Costa, L. Cotrim da Cunha, P.M. Cox, A.V. Eliseev, S. Henson, M. Ishii, S. Jaccard, C. Koven, A. Lohila, P.K. Patra, S. Piao, J. Rogelj, S. Syampungani, S. Zaehle, and K. Zickfeld, 2021: Global Carbon and other Biogeochemical Cycles and Feedbacks. In Climate Change 2021: The Physical Science Basis. Contribution of Working Group I to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change [Masson-Delmotte, V., P. Zhai, A. Pirani, S.L. Connors, C. Péan, S. Berger, N. Caud, Y. Chen, L. Goldfarb, M.I. Gomis, M. Huang, K. Leitzell, E. Lonnoy, J.B.R. Matthews, T.K. Maycock, T. Waterfield, O. Yelekçi, R. Yu, and B. Zhou (eds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA, pp. 673–816, https://doi.org/10.1017/9781009157896.007
- Prather, M.J.; Hsu, J.; DeLuca, N.M.; Jackman, C.H.; Oman, L.D.; Douglass, A.R.; Fleming, E.L.; Strahan, S.E.; Steenrod, S.D.; Søvde, O.A.; et al. Measuring and modeling the lifetime of nitrous oxide including its variability. J. Geophys. Res. Atmos. 2015, 120, 5693-5705. https://doi.org/10.1002/2015JD023267
- Tian, H.; Xu, R.; Canadell, J.G.; Thompson, R.L.; Winiwarter, W.; Suntharalingam, P.; Davidson, E.A.; Ciais, P.; Jackson, R.B.; Janssens-Maenhout, G.; et al. A comprehensive quantification of global nitrous oxide sources and sinks. Nature 2020, 586, 248-256. https://doi.org/10.1038/s41586-020-2780-0
Funding acknowledgements
Belgian Science Policy (Belspo) / European Space Agency (ESA) PRODEX program under the HIRS and HIRS2 projects (PEA 4000134591 and 4000144088)
European Space Agency Climate CHange Initiative (ESA CCI) LOng-LIved greenhouse gas PrOducts Performances (LOLIPOP)