AAAR 34th Annual Conference
October 12 - October 16, 2015
Hyatt Regency
Minneapolis, Minnesota, USA
Abstract View
Statistical Analysis of Aerosol, Cloud Condensation Nuclei (CCN), Cloud Base Temperature and Pressure in Summer-time North Dakota
JAMIE EKNESS, David Delene, University of North Dakota
Abstract Number: 728 Working Group: Aerosols, Clouds, and Climate
Abstract Aerosols affect cloud micro-physical properties and enhance the formation of precipitation. Understanding aerosol properties, such as CCN concentration, is key to determining precipitation formation. North Dakota has a wide range of aerosol concentrations which makes it an ideal location to test how environmental properties such as cloud base CCN concentration, temperature and cloud base pressure affect surface based precipitation. North Dakota has been the location of four Polarimetric Cloud Analysis and Seeding Test (POLCAST) field projects. During the summers of 2008, 2010, and 2012 aircraft measurements were made during 30 flights in eastern North Dakota.
During the summer of 2012, both the Droplet Measurement Technologies (DMT) and University of Wyoming (UWyo) CCN counters were used to make measurements. The DMT CCN counter measured at three supersaturations (0.2%, 0.3%, and 0.6%), while the UWyo CCN counter measured at 0.6%. Average cloud base CCN concentration measurements from the three POLCAST projects varied between 300#/cm$^(3) and 3000#/cm$^(3), with an overall average near 1400#/cm$^(3). The mean temperature at cloud base ranged from 5C to 16C with an average of 11.45C. Measurements of the mean cloud base pressure are between 998m to 1886m and an average of 1568m. Each of these micro-physical properties affect precipitation efficiency.