In-Situ Measurements of Aerosol Optical Properties using new Cavity Ring-Down and Comparison with more Traditional Techniques
| Strawa, Anthony | Ames Research Center |
| Hallar, Anna | NASA Ames Research Center |
| Arnott, Pat | Desert Research Institute |
| Covert, David | University of Washington |
| Elleman, Robert | University of Washington |
| Ogren, John | NOAA/CMDL |
| Schmid, Beat | Bay Area Environmental Research Institute |
| Luu, A | BAER |
Carbonaceous species (BC and OC) are responsible for most of the absorption associated with aerosol particles. The amount of radiant energy an aerosol absorbs has profound effects on climate and air quality. It is ironic that aerosol absorption coefficient is one of the most difficult aerosol properties to measure. A new cavity ring-down (CRD) instrument, called Cadenza (NASA-ARC), measures the aerosol extinction coefficient for 675 nm and 1550 nm light, and simultaneously measures the scattering coefficient at 675 nm. Absorption coefficient is obtained from the difference of measured extinction and scattering within the instrument. Aerosol absorption coefficient is also measured by a photoacoustic (DRI) instrument that was operated for the first time on an aircraft during the DOE Aerosol Intensive Operating Period (AIOP). This poster will report on measurements made with these new instruments and other in-situ instrument during the field study.
The DOE AIOP was conducted in May, 2003 over northern Oklahoma at the Southern Great Plains Test Site. One of the main purposes of the IOP was to assess our ability to measure extinction and absorption coefficient in situ. This poster compares measurements of these optical properties made by Cadenza, PA, TSI nephelometer, and three wavelength Particle soot absorption photometer (PSAP) aboard the CIRPAS Twin-Otter.
This poster will be displayed at the ARM Science Team Meeting.