Hi All A recent estimate of the climate problem is that a reduction of the solar input by 1.7 watts per square metre would give tolerable temperature conditions. This is 0.5% of the mean global 24 hour solar input. If marine cloud brightening was used for only 10% of the global surface an increase of reflectivity of 5% would be adequate.
The grey scale below has 20 bars ranging from black to white. Most people need to see at least three bars to detect the direction of the gradient. This shows that ship tracks give a contrast change far higher than would be required for climate control and that we would need image processing of satellite images to detect that it been done. There may be many tracks of which we are unaware. [cid:[email protected]] Stephen Emeritus Professor of Engineering Design School of Engineering University of Edinburgh Mayfield Road Edinburgh EH9 3DW Scotland 0131 650 5704 or 0131 662 1180 YouTube Jamie Taylor Power for Change From: [email protected] <[email protected]> On Behalf Of Geoengineering News Sent: 26 February 2023 09:59 To: [email protected] Subject: [geo] An Optical Flow Approach to Tracking Ship Track Behavior Using GOES-R Satellite Imagery This email was sent to you by someone outside the University. You should only click on links or attachments if you are certain that the email is genuine and the content is safe. https://ieeexplore.ieee.org/document/9837429 Authors Kelsie M. Larson, Lyndsay Shand , Andrea Staid, Skyler Gray, Erika L. Roesler, and Don Lyons 22 July 2022 Abstract:Ship emissions can form linear cloud structures, or ship tracks , when atmospheric water vapor condenses on aerosols in the ship exhaust. These structures are of interest because they are observable and traceable examples of MCB, a mechanism that has been studied as a potential approach for solar climate intervention. Ship tracks can be observed throughout the diurnal cycle via space-borne assets like the advanced baseline imagers on the national oceanic and atmospheric administration geostationary operational environmental satellites, the GOES-R series. Due to complex atmospheric dynamics, it can be difficult to track these aerosol perturbations over space and time to precisely characterize how long a single emission source can significantly contribute to indirect radiative forcing. We propose an optical flow approach to estimate the trajectories of ship-emitted aerosols after they begin mixing with low boundary layer clouds using GOES-17 satellite imagery. Most optical flow estimation methods have only been used to estimate large scale atmospheric motion. We demonstrate the ability of our approach to precisely isolate the movement of ship tracks in low-lying clouds from the movement of large swaths of high clouds that often dominate the scene. This efficient approach shows that ship tracks persist as visible, linear features beyond 9 h and sometimes longer than 24 h. [Fig. 1. - These figures show the result of the optical flow method applied to a manually-selected local cloud region, starting with an intersection of two ship tracks on June 17, 2019, at 07:02 UTC (a) and stepping forward in time, with snapshots shown at 6 (b), 12 (c), and 18 (d) hr later. The tracking algorithm is able to follow the movement of the cloud region well, and the tracks are still clearly visible 18 hr later. The center location of these images is $33^{\circ }$27’02.0”N $138^{\circ }$06’11.9”W.]<https://ieeexplore.ieee.org/mediastore_new/IEEE/content/media/4609443/9656571/9837429/shand1-3193024-large.gif> Fig. 1. These figures show the result of the optical flow method applied to a manually-selected local cloud region, starting with an intersection of two ship tracks on June 17, 2019, at 07:02 UTC (a) and stepping forward in time, with snapshots shown at 6 (b), 12 (c), and 18 (d) hr later. The tracking algorithm is able to follow the movement of the cloud region well, and the tracks are still clearly visible 18 hr later. Source: IEEE Xplore -- 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]<mailto:[email protected]>. To view this discussion on the web visit https://groups.google.com/d/msgid/geoengineering/CAHJsh98Y1RM_bKAxoryqsEkQFq-B9yy7K6k0dbvDqRKEHYrTSg%40mail.gmail.com<https://groups.google.com/d/msgid/geoengineering/CAHJsh98Y1RM_bKAxoryqsEkQFq-B9yy7K6k0dbvDqRKEHYrTSg%40mail.gmail.com?utm_medium=email&utm_source=footer>. The University of Edinburgh is a charitable body, registered in Scotland, with registration number SC005336. Is e buidheann carthannais a th’ ann an Oilthigh Dhùn Èideann, clàraichte an Alba, àireamh clàraidh SC005336. -- 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/PAXPR05MB80484FEEF262F045EEFECC48A7AE9%40PAXPR05MB8048.eurprd05.prod.outlook.com.
