TY - JOUR A1 - Seelig, Torsten A1 - Müller, Felix A1 - Tesche, Matthias T1 - Do Optically Denser Trade‐Wind Cumuli Live Longer? Y1 - 2023-06-29 VL - 50 IS - 13 SP - EP - JF - Geophysical Research Letters DO - 10.1029/2023GL103339 PB - N2 - Abstract

This study investigates the lifetime and temporal evolution of physical properties of trade‐wind cumuli based on tracking individual clouds in observations with the Advanced Baseline Imager aboard the geostationary GOES‐16 satellite during the “ElUcidating the RolE of Cloud–Circulation Coupling in ClimAte” (EUREC4A) campaign east of Barbados in winter 2020. A first application of our upgraded cloud‐tracking toolbox to measurements with high spatio‐temporal resolution (2 × 2 km2 and 1 min) provides probability density functions of lifetime and area of clouds that develop as a consequence of meso‐to‐synoptic scale motions. By separately considering clouds that exist during daytime and live in distinct lifetime intervals, we find that shallow marine cumuli live longer when they cover a larger surface area and show higher cloud optical thickness (COT). Besides the effect of COT, the scale of the atmospheric motions with which the clouds interact is also critical to their lifetime.

N2 - Plain Language Summary: We present a detailed investigation of the lifetime of Caribbean trade‐wind cumulus clouds and the temporal evolution of their physical properties based on geostationary observations with the Advanced Baseline Imager aboard the geostationary GOES‐16 satellite during the “ElUcidating the RolE of Cloud–Circulation Coupling in ClimAte” (EUREC4A) field experiment in winter 2020. The tracking of 2.7 million individual clouds in measurements with high spatio‐temporal resolution enables the investigation of processes that control the lifetime of shallow marine cumulus (SMC) clouds. Our analysis reveals that SMC clouds live longer when they span over a surface area that exceeds an order of tens of square kilometers. While these clouds show similar median cloud droplet size and number concentration compared to shorter‐lived clouds, they contain more liquid water and, thus, show a COT that is increased by about one third. Besides the effect of COT, we find that the scale of the atmospheric motions with which the clouds interact is also critical to their lifetime.

N2 - Key Points: First study of the life cycle of shallow marine cumulus based on observations with the Advanced Baseline Imager aboard GOES‐16.

Confirmation of the double power law in the distribution of cloud lifetime from measurements with a temporal resolution of 1 minute.

Cloud lifetime is related to large‐scale circulation and affects cloud optical thickness.

UR - http://resolver.sub.uni-goettingen.de/purl?gldocs-11858/10849 ER -