Retrievals of water vapour and temperature exploiting the far-infrared: application to aircraft observations in preparation for the FORUM mission

Panditharatne, Sanjeevani; Brindley, Helen; Cox, Caroline; Siddans, Richard; Murray, Jonathan; Warwick, Laura; Fox, Stuart

doi:https://doi.org/10.5194/amt-18-717-2025

Articles | Volume 18, issue 3

https://doi.org/10.5194/amt-18-717-2025

© Author(s) 2025. This work is distributed under
the Creative Commons Attribution 4.0 License.

https://doi.org/10.5194/amt-18-717-2025

© Author(s) 2025. This work is distributed under
the Creative Commons Attribution 4.0 License.

Articles | Volume 18, issue 3

Research article

|

10 Feb 2025

Research article |

| 10 Feb 2025

Retrievals of water vapour and temperature exploiting the far-infrared: application to aircraft observations in preparation for the FORUM mission

Sanjeevani Panditharatne, Helen Brindley, Caroline Cox, Richard Siddans, Jonathan Murray, Laura Warwick, and Stuart Fox

Supplement

https://doi.org/10.5194/amt-18-717-2025-supplement

Data sets

ERA5 hourly data on pressure levels from 1940 to present H. Hersbach et al. https://doi.org/10.24381/cds.bd0915c6

MERRA-2 inst3_3d_asm_Np: 3d,3-Hourly,Instantaneous,Pressure-Level,Assimilation,Assimilated Meteorological Fields V5.12.4 Global Modeling and Assimilation Office (GMAO) https://doi.org/10.5067/QBZ6MG944HW0

MERRA-2 inst1_2d_asm_Nx: 2d,1-Hourly,Instantaneous,Single-Level,Assimilation,Single-Level Diagnostics V5.12.4 Global Modeling and Assimilation Office (GMAO) https://doi.org/10.5067/3Z173KIE2TPD

FAAM C153 PIKNMIX-F flight: Airborne atmospheric measurements from core and non-core instrument suites on board the BAE-146 aircraft Facility for Airborne Atmospheric Measurements et al. https://catalogue.ceda.ac.uk/uuid/6a2bc7a1edc34650bd41e0f958cbd50a/

Earth System Research Laboratory Carbon Cycle and Greenhouse Gases Group Flask-Air Sample Measurements of CO2, CH4, CO, N2O, H2, SF6 and isotopic ratios at Global and Regional Background Sites, 1967–Present, Version 2.0 E. Dlugokencky et al. https://doi.org/10.7289/V5CN725S

Short summary

Observations from the upcoming European Space Agency’s Far-Infrared Outgoing Radiation Understanding and Monitoring (FORUM) satellite are theorised to be highly sensitive to distributions of water vapour within Earth’s atmosphere. We exploit this sensitivity and extend the Infrared Microwave Sounding retrieval scheme for use on observations from FORUM. This scheme is evaluated on both simulated and observed measurements and shows good agreement with references of the atmospheric state.