Observing the timescales of aerosol-cloud interactions in snapshot satellite images

<div>Cloud processes and their response to perturbations happens at a variety of timescales. These timescales are related to processes such as updrafts and mixing, the formation of precipitation and changes in the background meteorology.</div><div>&#160;</div><div>Satellites often give a static picture of the world. A single snapshot from an overpass gives a wide view of the cloud field, but not motion within it. Previous studies have used multiple overpass or geostationary satellites to build up a picture of cloud development. Here we use the aerosol perturbation itself as the time axis. <br><br>Ships emit large amounts of aerosol into the boundary layer, often in comparatively clean locations. This aerosol can modify the properties of these clouds, creating linear cloud formations known as shiptracks. Using ship SO_x emission information derived from ship transponder data, we link the aerosol perturbation to the properties of the shiptrack. By coupling the ship location to reanalysis wind fields, we determine the time since emission for positions along a shiptrack, providing a time axis in a single snapshot image. <br><br>We use this combined satellite/aerosol perturbation dataset to investigate the timescales for clouds responses to the aerosol perturbation from ships, linking it to the cloud and meteorological states as well as the properties of the aerosol perturbation.</div>