Life Cycle of Shallow Marine Cumulus Clouds From Geostationary Satellite Observations. Issue 22 (15th November 2021)

• Record Type: Journal Article
• Authors: Seelig, Torsten; Deneke, Hartwig; Quaas, Johannes; Tesche, Matthias
• Is Part Of: Journal of geophysical research. Volume 126:Issue 22(2021)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2021-11-15
• Subjects: cloud tracking -- geostationary observations -- shallow marine cumulus -- life cycle -- cloud physical properties; Atmospheric physics -- Periodicals; Geophysics -- Periodicals; 551.5
• DOI: 10.1029/2021JD035577
• Languages: English
• ISSNs: 2169-897X

Abstract

Abstract: An analysis of the life cycle of shallow marine cumulus clouds is presented based on geostationary observations by the Spinning Enhanced Visible and InfraRed Imager aboard Meteosat Second Generation (MSG‐SEVIRI). Trajectories of about 250, 000 individual shallow marine cumulus clouds have been derived by applying Particle Image Velocimetry to the Satellite Application Facility on Climate Monitoring CLoud property dAtAset using SEVIRI for a region in the trade wind zone centered around the Canary Islands in August 2015. The temporal evolution of the physical properties of these clouds allows to characterize cloud development and to infer the distribution of cloud life time and cloud extent. In the derived data set, the life time distribution follows a double power law with most clouds existing on a time scale of tens of minutes. The cloud physical properties, available during daytime, are analyzed along the cloud tracks. Relative time series of cloud extent, cloud water path, cloud droplet effective radius at cloud top, cloud optical thickness, and cloud droplet number concentration for clouds in two temporal ranges reveal conditions that can be attributed to long‐lasting clouds. Clouds of a certain horizontal extent and cloud top height as well as cloud droplet radius show longer life times if they are optically more dense, i.e., have a higher droplet number concentration. Furthermore, the investigation of the content of liquid cloud water regarding cloud life time and cloud extent shows that small short‐living clouds significantly contribute to cloud radiative effects. Plain Language Summary: A comprehensive analysis of the life cycle of shallow marine cumulus clouds is presented based on measurements of a specialized instrument, called SEVIRI, aboard Meteosat's Second Generation geostationary meteorological satellite. A new method is applied to derive the physic‐property temporal evolution of approximately 250, 000 individual clouds in a region around the Canary Islands during August 2015. Several constraints are applied to infer the relationship between cloud life time and various cloud parameters. The study reveals that cloud life time is related to the optical thickness when constrained by horizontal extent, cloud top height, and droplet radius. The analysis further shows that small short‐living clouds significantly contribute to cloud radiative effects. Key Points: The life cycle of shallow marine cumulus clouds is inferred using a passive space‐based geostationary instrument Life cycle is quantified by top temperature/height, cloud extent, cloud water path, optical thickness, and droplet radius/number concentration Cumulus clouds of a certain horizontal extent, cloud top height as well as droplet radius live longer if they are optically denser