Article strongly indirectly related to SRM and in particular MCB

[E Durbrow]

[Apologies if already posted. MCB people: any reactions?]

This study does not explicitly mention SRM but it seems more than tangentially related to MCB.

Abstract: https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2019GL084700

Ships often burn heavy fuel oil, typically creating large amounts of particulate pollution, which is known to modify cloud properties. This creates linear cloud formations, known as shiptracks. In this work, we investigate how the occurrence and properties of shiptracks are related to the particulate emissions from individual ships. We show that the introduction of regulation on ship fuel has already produced a dramatic effect on cloud properties, with shiptracks almost disappearing completely in regions where fuel is regulated. With this new information about the particulates produced by specific ships, we also show that many shiptracks are likely undetected by current identification methods. This study also provides a pathway towards measuring ship emissions using satellite data.

Key points

Ship fuel sulphate content controls have already had a significant impact on shiptracks

Almost half of shiptracks may be undetected by current methods

A potential method for retrieving ship emissions using cloud properties is demonstrated

Press summary: https://www.sciencedaily.com/releases/2019/11/191105104420.htm

[Stephen Salter]

Hi All

It was ship tracks that got Twomey going.  You have to have a contrast change of more than 15% so see a track. To offset thermal damage up to now we need a contrast change of only about 2.5%   It is better to use a lower dose over a wider area.  You will still be able to detect them by taking lots of satellite images shifting them to align the source point, rotating them to align wind direction and then adding an taking an average.

They do not always appear, perhaps only a third of the time in places where ships have been but faint ones may still be there.  Occurrence will depend on turbulence and humidity.

I hope that the attached paper  on numerical simulation will be of more interest to this group than to Environmental Research Letters who rejected it.

Stephen

Emeritus Professor of Engineering Design. School of Engineering, University of Edinburgh, Mayfield Road, Edinburgh EH9 3DW, Scotland S.Sa...@ed.ac.uk, Tel +44 (0)131 650 5704, Cell 07795 203 195, WWW.homepages.ed.ac.uk/shs, YouTube Jamie Taylor Power for Change

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