SAILCORSIPP

Characterization of orography-influenced riming

1 September 2022 - 15 June 2023

Lead Scientist: Maximilian Maahn

Observatory: AMF (ARM Mobile Facility 2) - GUC

A comprehensive understanding of precipitation formation processes is required to understand how the water budget is changing in a warming climate. In mid-latitudes, most precipitation is generated through the ice phase in mixed-phase clouds, but the exact pathways through which ice, liquid water, cloud dynamics, orographic forcing, and aerosol particles are interacting during ice, snow, and rain formation are not well understood. This is particularly true for riming and secondary ice production (SIP) processes that are likely related to the largest uncertainties with respect to quantitative snowfall formation. Filling the gaps in our understanding of SIP and riming is especially crucial for mountainous regions that are particularly vulnerable to changes in precipitation and the water budget such as the ratio between rain and snowfall. CORSIPP is a research project dedicated to understanding riming and SIP processes in complex terrain. For this, we will join the ARM Surface Atmosphere Integrated Field Laboratory (SAIL) campaign and extend the AMF2 instrumentation by a scanning W-band cloud radar together with a novel in situ snowfall camera (VISSS: Video In Situ Snowfall Sensor) for the second SAIL winter season in the Colorado Rocky Mountains. Combining spectral polarimetric and multi frequency Doppler radar observations with empirical and Bayesian machine learning retrieval techniques, we will identify riming and SIP events and quantify their impact on snowfall rates. The observed processes will be related to environmental conditions such as temperature, humidity, and liquid water path as well as cloud dynamics.