https://acp.copernicus.org/preprints/acp-2021-148/
Estimating the potential cooling effect of cirrus thinning achieved via the seeding approach Jiaojiao Liu and Xiangjun Shi Show author details Received: 19 Feb 2021 – Accepted for review: 26 Feb 2021 – Discussion started: 01 Mar 2021 Abstract. Cirrus thinning is a newly emerging geoengineering approach to mitigate global warming. To sufficiently exploit the potential cooling effect of cirrus thinning with the seeding approach, a flexible seeding method is used to calculate the optimal seeding number concentration, which is just enough to prevent homogeneous ice nucleation from occurring. A simulation using the Community Atmosphere Model version 5 (CAM5) with the flexible seeding method shows a global cooling effect of 1.36 ± 0.18 W m−2, which is approximately two-thirds of that from artificially turning off homogeneous nucleation (−1.98 ± 0.26 W m−2). However, simulations with fixed seeding ice nuclei particle number concentrations of 20 and 200 L−1 show a weak cooling effect of −0.27 ± 0.26 W m−2 and warming effect of 0.35 ± 0.28 W m−2, respectively. Further analysis shows that cirrus seeding leads to a significant warming effect of liquid and mixed-phase clouds, which counteracts the cooling effect of cirrus clouds. This counteraction is more prominent at low latitudes and leads to a pronounced net warm effect over some low latitude regions. The sensitivity experiment shows that cirrus seeding carried out at latitudes with solar noon zenith angles greater than 12° could yields a stronger global cooling effect of −2.00 ± 0.25 W m−2. Overall, the potential cooling effect of cirrus thinning is considerable, and the flexible seeding method is essential. How to cite. Liu, J. and Shi, X.: Estimating the potential cooling effect of cirrus thinning achieved via the seeding approach, Atmos. Chem. Phys. Discuss. [preprint], https://doi.org/10.5194/acp-2021-148, in review, 2021. -- You received this message because you are subscribed to the Google Groups "geoengineering" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/geoengineering/CAJ3C-06CHf%3DwDv1fKsD59cLNasNWs9J8--cKv21Gs7VsP3hFfg%40mail.gmail.com.
