Cirrus clouds play an important role in the Earth’s radiation budget. Whether soot from aircraft emission would change the property of large-scale cirrus clouds has been a critical question. Recently, Prof. Jialei Zhu and co-authors published a paper on AGU advances with the title of “Decreased aviation leads to increased ice crystal number and a positive radiative effect in cirrus clouds”. Their study showed that the unprecedented decrease in aircraft traffic as a result of the COVID-19 pandemic leads to a significant increase in ice crystal number as detected by satellite. An increase in ice crystal number and positive radiative effect is estimated using a state-of-the-science earth system model if the reduction in aviation activity continues for the foreseeable future. A relatively small positive global average radiative effect of 21 mW m-2 is estimated if a decrease in aircraft traffic continues, with an average of up to 64 mW m-2 over the area where aviation is most active. As adoption of blending biofuel in the aviation sector would lead to similar reductions (50~70%) of aircraft soot emissions in the future, remarkable changes in the microphysical properties of large-cirrus clouds and positive radiative effects can be expected relative to a case with no biofuel blending.
Please find the full text with the link: https://doi.org/10.1029/2021AV000546.
Jialei Zhu, Joyce E. Penner, Anne Garnier, Olivier Boucher, Meng Gao, Lei Song, Junjun Deng, Cong-qiang Liu, Pingqing Fu (2022). Decreased aviation leads to increased ice crystal number and a positive radiative effect in cirrus clouds. AGU Advances, 3, e2021AV000546.
