Yair Cohen

Postdoctoral Researcher

California Institute of Technology and Jet Propulsion Laboratory

1200 E. California Blvd.
MC 131-24
Pasadena, CA 91125

Office: 233 Linde+Robinson

 

Biography

Currently I am a post doctorate researcher working with Tapio Schneider in the Climate Dynamic group at Caltech GPS. The main focus of my research is to examine entrainment (mixing) in clouds and specifically in deep (precipitating) convection with the goal of improving the ability of climate models (GCMs) to better represent the (statistical effect) of clouds.

I gained my M.Sc. and PhD in the Hebrew University of Jerusalem, where my research was in more idealized geophysical fluid dynamics. During my M.Sc. guided by professor Nathan Paldor, I developed analytical and semi-analytical theories for non-harmonic theories for topographic waves and in collaboration with professor Joel Sommeria reproduced their key aspects in state of the art laboratory experiments in LEGI-Coriolis, Grenoble – France. In my PhD with Prof. Nathan Paldor and in collaboration with Yona Dvorkin (GSI) I examined the stability of ocean eddies. In this work we found that rather complex basic state structures, which complicate the ability to find numerical solutions, allow the stability of ocean eddies with density fronts (as observed in nature).

Later I had a short post doctorate research with professor Nili Harnik and professor Eyal Heifetz in the geophysics department of Tel Aviv university. In this project we examined the validity of the gradient wind balance to the pressure maps at the top of simulated hurricanes and found that often the gradient wind balance is not a valid solution. In these cases, a new, flow regime develops in which the radial pressure gradient acts on the redial wind (outflow) at the top of the storm. This may have the potential to effect the intensity of the storm.

Google Scholar Page

HomePage in the Jet Propulsion Laboratory wepage

 

 

Publications

  • Tan, Z., C. M. Kaul, K. G. Pressel, Y. Cohen, T. Schneider, and J. Teixeira, 2017: An extended eddy-diffusivity mass-flux scheme for unified representation of subgrid-scale turbulence and convection. Journal of Advances in Modeling Earth Systems, submitted.
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