Advances in CALIPSO (IIR) cirrus cloud property retrievals – Part 2: Global estimates of the fraction of cirrus clouds affected by homogeneous ice nucleation

Mitchell, David L.; Garnier, Anne

doi:https://doi.org/10.5194/acp-25-14099-2025

Articles | Volume 25, issue 20

https://doi.org/10.5194/acp-25-14099-2025

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

https://doi.org/10.5194/acp-25-14099-2025

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

Articles | Volume 25, issue 20

Research article

|

29 Oct 2025

Research article |

| 29 Oct 2025

Advances in CALIPSO (IIR) cirrus cloud property retrievals – Part 2: Global estimates of the fraction of cirrus clouds affected by homogeneous ice nucleation

David L. Mitchell and Anne Garnier

Supplement

https://doi.org/10.5194/acp-25-14099-2025-supplement

Data sets

CALIPSO Infrared Imaging Radiometer (IIR) Level 2 Track, V4-51 NASA/LARC/SD/ASDC https://doi.org/10.5067/IIR/CALIPSO/CAL_IIR_L2_Track-Standard-V4-51

CALIPSO Lidar Level 2 5 km Cloud Layer, V4-51 NASA/LARC/SD/ASDC https://doi.org/10.5067/CALIOP/CALIPSO/CAL\_LID\_L2\_05kmCPro-Standard-V4-51

Short summary

Arguably the greatest knowledge gap in cirrus cloud research is the relative roles of homogeneous and heterogeneous ice nucleation in cirrus cloud formation. Since this depends on temperature, latitude, season and topography, a satellite remote sensing method was developed to measure cirrus cloud properties. It was found that cirrus clouds strongly affected by homogeneous ice nucleation may account for over half of the overall cirrus cloud radiative effect during winter outside the tropics.