Precipitation Studies

Why?

The measurement of precipitation is one of the fundamental goals of our science. Precipitation reaching the surface is a key component of the earth's hydrological cycle and represents an important source of water for human consumption. Precipitation also impacts elements as diverse as the salinity of the oceans, and vegetation, flora and fauna.

Measurements and Modeling of Precipitation:

Over the years we have studied one of the central issues in precipitation physics, namely, the size distribution of the raindrops. The latter is of central importance in fields such as the remote measurement of rainfall with radar, the evaporation of precipitation below cloud, soil erosion, and hazards to aviation resulting from evaporatively driven downdrafts. The following describes a few of the issues addressed:

• Ground based measurements of raindrop spectra.
• Parameterization of drop-size-distributions for the purpose of solving the inversion of rainrate from radar measured variables.
• Dynamical and microphysical modelling of raindrop spectral evolution.
• Studies of the generation of microbursts by evaporative cooling and their sensitivity to collision-coalescence and breakup.
• Comparisons between observations of spectral evolution with altitude and model results.
• Graupel melting studies.
• Modelling of the effect of precipitation on the shelter temperature

References:

Feingold, G. and Z. Levin, 1986: The lognormal fit to raindrop spectra from frontal convective clouds in Israel. J. Clim. Appl. Meteor., 25, 1346--1363.

Feingold, G. and Z. Levin, 1987: The lognormal size distribution of raindrops: application to differential reflectivity measurements of rainfall (Z$ _ {DR}$). J. Atmos. Ocean. Tech., 4, 377--382.

Feingold, G., S. Tzivion and Z. Levin, 1988: The evolution of raindrop spectra. Part I: stochastic collection and breakup. J. Atmos. Sci., 45, 3387--3399.

Feingold, G., S. Tzivion and Z. Levin, 1991: The evolution of raindrop spectra: Part III. Downdraft generation in an axisymmetrical model. J. Atmos. Sci., 48, 315--330.

Levin, Z., G. Feingold, S. Tzivion and A. Waldvogel, 1991: The evolution of raindrop spectra: comparisons between modelled and observed spectra along a mountain slope in Switzerland. J. Appl. Meteor., 30, 893--900.

Segal, M. and G. Feingold, 1993: On the impact of summer daytime local convective cloud systems on the shelter temperature. J. Appl. Meteor., 32, 1569--1578.