Fundamental understanding of reactive nitrogen in the global upper troposphere

Reactive nitrogen is central to the influence of the upper troposphere throughout the global troposphere. We're developing new and examining existing data to address persistent uncertainties in the sources, processing, fate and environmental consequences of reactive nitrogen in the upper troposphere.


People: Nana Wei, Rebekah Horner, Robert Ryan, Karn Vohra

Funding: £1.3 million European Research Council Starting Grant. European Commission project page.

ERC Award Media Coverage:

Open The World: 51 Nationalities Among the Winners of the 2019 ERC Starting Grants

£1.3 million grant for global atmosphere research

South African National Research Foundation ERC Award Press Release

Serendipitous Discoveries:

Potential Impact of Rocket Launch and Space Debris Ablation Emissions on the Atmosphere

External Collaborators: NASA ATom Science Team, TROPOMI NO2 data developers, Pandora Pandonia Network Team, Izana MAX-DOAS data providers

Data and Tools Used: aircraft (NASA DC8, MOZAIC, IAGOS) observations, GEOS-Chem, TROPOMI, Pandora, MAX-DOAS

New Datasets:

Cloud-sliced nitrogen dioxide (NO2) in the global upper troposphere derived from TROPOMI. [Link to Data]

Rocket launch and re-entry ablation air pollutant emissions impact on stratospheric ozone and global climate. [Link to Data]

New Software: Cloud-slicing algorithm to retrieve global upper tropospheric NO2 from TROPOMI. [Code], [Documentation]


E. A. Marais, D. J. Jacob, S. Choi, J. Joiner, M. Belmonte-Rivas, R. C. Cohen, S. Beirle, L. T. Murray, L. Schiferl, V. Shah, L. Jaeglé, Nitrogen oxides in the global upper troposphere: interpreting cloud-sliced NO2 observations from the OMI satellite instrument, Atmos. Chem. Phys., 18, 17017-17027, 2018. [PDF]

R. G. Ryan, E. A. Marais, C. J. Balhatchet, S. D. Eastham, Impact of rocket launch and space debris air pollutant emissions on stratospheric ozone and global climate, Earth's Future, doi:10.1029/2021EF002612, 2022. [PDF].

E. A. Marais, J. F. Roberts, R. G. Ryan, H. Eskes, K. F. Boersma, S. Choi, J. Joiner, N. Abuhassan, A. Redondas, M. Grutter, A. Cede, L. Gomez, M. Navarro-Comas, New observations of upper tropospheric NO2 from TROPOMI, Atmos. Meas. Techn., 14, 2389-2408, doi:10.5194/amt-14-2389-2021, 2021. [PDF]

Disclaimer: This project has received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (grant agreement No. 851854)

Research Media Coverage:

The Guardian, Billionaire space cowboys could become heroes by focusing on the climate crisis.

Public Engagement:

The Conversation, Space tourism: rockets emit 100 times more CO2 per passenger than flights – imagine a whole industry, July 2021.


Impact of rocket launch and re-entry heating pollution on ozone and climate, poster by Eloise Marais at the 10th International GEOS-Chem Meeting, Washington University in St. Louis, USA, 8 June. [PDF]