Fig. 2: There are cloud property changes even when there are no visible tracks.
From: Invisible ship tracks show large cloud sensitivity to aerosol
a,b, Comparing Nd (a) and LWP (b) in the Chilean Sc between those days when ship tracks are visible (blue) and those when none are visible (orange) in the region. Plotted are ratios of hourly means of in-track and out-of-track properties, so that a value larger than 0% means an enhancement in the track. Shaded areas show standard errors of the means. LWP anomalies are given in 2 h means rather than 1 h because of noisier data. Retrievals from the MODIS-cloud product on Aqua and Terra41, all for 2014–2019, 25% of days with visible tracks. Also, there are measurable responses to ship emissions everywhere.c, A plot of a comparison of in-track and out-of-track properties in four regions: the Chilean (Chil., light blue) and Angolan/Namibian (Ango., blue) Sc, and the Cu around the Azores (Azor., navy) and Cabo Verde (C.Ver., green). The regions are shown in different colours representing the ship track location data of around six days. d–f, Plots showing relative Nd (d), LWP (e) and albedo (f) anomalies. Shaded areas show standard errors of the means. Retrievals from the MODIS-cloud product on Aqua and Terra41, all for 2014–2019. Map of the different regions from cartopy42.
