Do Optically Denser Trade‐Wind Cumuli Live Longer?

Abstract

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.

Keywords

• shallow convection
• trade‐wind cumuli
• life cycle
• EUREC4A
• GOES‐16 ABI