Fig. 3: More droplets in Sc, more LWP in Cu.
From: Invisible ship tracks show large cloud sensitivity to aerosol
a,b, Heatmap of relative Nd (a) and LWP anomaly (b), that is, mean of in-track properties divided by mean of out-of-track properties. Nd responses are strongest in the Sc regions, but LWP responses are strongest in the trade Cu. Retrievals from MODIS-cloud product on Aqua and Terra41, all for 2014–2019. Map from cartopy42. c, The possible mechanism for a more positive LWP response in weak-inversion regions. Previous ship track studies focused on regions with stable conditions and relatively high background Nd (top). There, cloud depth cannot increase because of the strong inversion topping the cloud. Invisible tracks occur more often in unstable, low background Nd clouds (bottom). When more CCN are provided by a ship, these clouds can deepen. As liquid water content (LWC) increases linearly with height, LWP, its integral, increases quadratically.
