On the properties of greenCu: continental, organized shallow clouds

Prevalent over the world’s oceans and continents, shallow clouds still comprise a main aspect of the uncertainty related to cloud feedback and climate sensitivity. Compared to shallow clouds over the ocean, confined to specific marine environments, shallow cumulus (Cu) over land occur in diverse locations throughout the globe.

Motivated by an intriguing observation regarding the universality of continental shallow Cu fields regardless of their geographical location, we explore their similarities. We combine satellite observations, along with machine learning classification and numerical modelling to show that these cloud fields share many important properties, such as the patterns they form and their tendency to form over and near forests and vegetated lands, thus termed greenCu.

Moreover, we show that in spite of their occurrence in different climatic regions, from the tropics to mid- and high-latitudes, greenCu fields are associated with similar large-scale meteorological conditions.