This is a past event.

Our understanding of snowflakes is biased toward regions where they can be easily observed.   For example, when modern airborne imaging instruments are brought to the upper regions of thunderstorms, we observe ice particle shapes that are not found in typical textbooks on the subject.   In particular, chains of frozen droplets are found in Midwestern storms, which are likely formed by electrical forces acting on frozen droplets in the upper regions of the storm.   These same electrical forces are responsible for lightning, which produces Nitrogen Oxides (NOx).    Lightning is a major source of NOx to the atmosphere.

In this presentation I explore the relationships between ice particle morphology, lightning, and NOx, based upon data collected in the Deep Convective Clouds and Chemistry experiment in 2012.   The goal of this work is to relate the chemical properties of thunderstorm-processed air to the ice found in the storm and to the physical processes that determine the ice particle morphology, such as aggregation, depositional growth, electrification, etc.   I also describe the airborne laboratories used for these studies and how university faculty and students can use them for their own research interests.      

Seminar by:

Jeffrey L. Stith, PhD

Senior Scientist

National Center for Atmospheric Research