In this case from the Southern Ocean, the 3-6-7 channel image from MODIS on Terra, taken during the day pass on May 17, 2014, clearly shows a plume of thick, closed-cell MSc cloud transitioning to open-cell convection. HYSPLIT trajectories indicate that the flow in the boundary layer during the preceding 24 hours was from the south. What is the source of the mystery plume?
Backing up a day, the Terra pass on May 16 is difficult to interpret, but the Aqua pass is the key to the mystery:
It seems that under southerly flow, given the background environment, Coronation Island (located at -60.571 N, -45.676 E) generated a cloud tail in the MSc deck with elevated LWP. The trajectory analysis reveals that flow in the boundary layer took roughly 21 hours to advect north to where the distinct change in microphysics and dynamics becomes obvious. This is a unique example of a mechanically forced LWP perturbation in boundary layer cloud driving aerosol-cloud-precipitation feedbacks and triggering a downstream change in boundary layer structure.