Konwersatorium im. Jerzego Pniewskiego

An outstanding feature of atmospheric flows is the range of spatial and temporal scales involved. Development of rain through gravitational collisions of cloud droplets concerns processes at sub-centimeter scales. Size distribution of cloud droplets within turbulent cumulus and stratocumulus clouds in the tropics and subtropics, where the solar insolation is at its peak, significantly affects the amount of solar radiation reflected back to space, and thus the planetary albedo. Tropical deep convective clouds, often organized into mesoscale convective systems with horizontal scales of hundreds of kilometers, drive planetary-scale Walker and Hadley circulations,which play a critical role in the Earth energy and water cycles. For all these scales, numerical modeling - either for scientific researchor for practical purposes, like the numerical weather prediction - plays an important role.

In this lecture, I will present examples of multiscale modeling approaches to selected problems in atmospheric fluid dynamics. These will include collision/coalescence of cloud droplets, turbulent entrainment into convective clouds, and representation of cloud processes in climate models.