Collaborative Research: Impact of Snowfall Processes on Potential Vorticity Generation in High-Latitude Snow Events

University Of Wisconsin-Madison, Madison WI

Investigators

Abstract

Precipitation processes, such as evaporation and condensation, have the ability to affect the large-scale weather systems in which they are embedded. This research award will provide funding for a collaborative team of researchers to study how snowfall processes affect overall storm evolution. The research will make use of ground-based instrumentation, remote sensing, and numerical modeling to gain a better picture of the profile of snowflakes in a storm and whether the models are representing the snow correctly. Differences between the observations and the models will indicate the relative importance of snowfall processes in storm events. The result of the award should be improved modeling for both weather and climate purposes and enhanced international scientific collaboration between the United States, Norway and Sweden. Students would be educated and trained, ensuring the development of the next generation of scientists. The research team plans to contrast real-world observations of the spatial and vertical distributions of snowfall with the representation in numerical models, and seek to quantify the impacts of any differences on storm evolution. The goal would be to better define the relationships between microphysical and dynamical processes for three meteorologically distinct high-latitude meteorological extremes (Alaska, Norway and Sweden). The observational component of the research will include in-situ measurements of snowflake statistics using the Multi-Angle Snowflake Camera and remote sensing from radars using an existing satellite radar snowfall retrieval scheme. The modeling aspect of the work would be performed using the HARMONIE, ECMWF-IFS, and WRF systems. Three main objectives will be addressed in the project: 1) Quantify real-world vertical profiles of snowfall microphysical properties with uncertainties at each site, 2) Compare observations of the vertical profile of precipitation properties with their representation in numerical model for different synoptic conditions, and 3) Evaluate the impact of discrepancies in modeled and observed precipitation profiles on potential vorticity modification for forecast storm events at each site.