Cloud microphysics, turbulence and telemetry

Started: October 2016
Supervisor: van Reeuwijk, M.

Description of Research

Clouds involve processes extending over a range of length scales; from cloud systems of the order of thousands of kilometers, to microscopic aerosols and cloud droplets, and times scales of the order of fractions of seconds to years. This makes the simulation and modelling of clouds a big challenge, deficiencies in which can lead to undesirable results. Additionally, clouds are being represented on a more individual basis in recent operational global climate models and it is important that the understanding of mixing and microphysics in cloud structures are improved. Of special interest are small, non precipating cumulus clouds as they contribute more significantly to cloud fraction than larger clouds, and are prevelant over both ocean and land. Special focus is given to the edges of these clouds due to the increased complexity. The complexity arises due to mixing at the cloud-clear air interface which results in the entrainment of dry, subsaturated environment air into the moist cloudy air, causing various thermodynamic and microphysical changes in cloud properties.

My PhD research involves a numerical study of the interaction of cloud boundaries with the environment. The numerical code SPARKLE will be complemented with a microphysics routine to perform Direct Numerical Simulations on a cloud-environment setup. The effect of entrainment on the cloud droplets and microphysics on cloud edges will be studied with special focus on the growth of the cloud droplet size distributions.

Background

Vishnu is a graduate with a BTech in Mechanical Engineering from India and an MSc in Aerospace Engineering from Delft University of Technology.

Vishnu Satheesh Kumar Nair

Fluid Mechanics Research Student 
Department of Civil & Environmental Engineering 
Imperial College London SW7 2AZ 
v.satheesh-kumar-nair16@imperial.ac.uk