Blue Waters Professor
Dept. of Atmospheric Sciences
Univ. Illinois at Urbana-Champaign
217-244-4250
slasher@illinois.edu

NEWS

LATEST PUBLICATION

Shown below is an animated gif produced from our most recent published study, Entrainment in a Simulated Supercell Thunderstorm. Part I: The Evolution of Different Entrainment Mechanisms and Their Dilutive Effects.  J. Atmos. Sci., 78, 2725-2740.  In this study, we were examining and quantifying different ways that entrainment occurs during the developing and mature stages of a supercell thunderstorm.  In the animation below, a 3D visualization of the thunderstorm core (here, the surface bounding an updraft exceeding 20 m/s) is colored by air motion into the core surface (blue; entrainment) or air motion out of the core surface (red; detrainment).  What can be seen in the animation is the discrete “ribbons” of overturning motions introduce air into the core of the thunderstorm.  They do not reach all the way into the interior of the core, allowing part of the updraft to still remain unaffected (“undiluted”) by entrainment, as shown and discussed in the paper.  This work was supported by an award from NSF:  AGS17-25190, and used the Blue Waters Supercomputer, also supported by NSF and the State of Illinois.

 

AWARD

Professor Lasher-Trapp was awarded the American Meteorological Society’s Edward N. Lorenz Teaching Excellence Award in January 2021. This award recognized Professor Lasher-Trapp “for creating active learning and welcoming classroom environments, expanding student experiences, and advocating for women in science.” As the award recipient, Lasher-Trapp gave a keynote talk during the AMS 30th Conference on Education on January 14.

 

GROUP OVERVIEW

Our group uses numerical modeling with observational analysis to investigate research problems associated with the development of clouds and precipitation. Our successes in the last decade, often with other collaborators, include demonstrating when giant aerosol particles are (or are not) important in warm rain formation, how the productivity of the warm rain process may change in a future warmer climate, the importance of variability resulting from entrainment and mixing upon accelerating or preventing warm rain formation, the influence of a strong warm rain process upon ice production in oceanic cumuli, and the behavior of clouds as shedding thermals that thus entrain air through their leading edges. We have published multiple articles in peer-reviewed journals and regularly present our work at the AMS Cloud Physics Conference and the International Conference on Clouds and Precipitation.

We have also contributed to the development of tools for visualization of ground-based and airborne radar data and high-resolution numerical simulations of clouds, evaluated the performance of aircraft-mounted cloud microphysical probes, and tested microphysical parameterizations in larger-scale cloud models. Finally, we have contributed to science education through studies on improving undergraduate understanding of the nature of science, and the development and evaluation of research-based laboratories for undergraduates in atmospheric science.

 

OUR FUTURE

We continue to shift our emphasis toward microphysical processes in deep convection.  Current projects include using very high-resolution simulations on the Blue Waters supercomputer to investigate the effects of entrainment in thunderstorms and its effect upon precipitation (NSF award), aerosol effects upon convective outflows and cold pools (DOE- ASR award), and studying the possible effects of climate change on severe weather, including hail storms and wind storms (NSF award, Jeff Trapp lead PI).