Lunch Talk

Will be Tuesday April 2, 2013 at 12:15PM

Location:
UMC 353, University of Colorado Boulder
Bring your lunch, the talk starts at about 12:15

Presenter:
Dr. Rebecca Washenfelder,
Research Scientist, National Oceanic and Atmospheric Administration

Title:
Chemical and optical properties of organic aerosol

Abstract:
Recent advances in optical spectroscopy have led to new broadband cavity enhanced spectrometers (BBCES) that combine high-finesse optical cavities with high-powered LED light sources, spectrally resolving the light output with a grating spectrometer. This technique can be used to make sensitive, in situ measurements of optical extinction. Organic compounds contribute a large fraction of aerosol mass, and glyoxal has been identified in previous laboratory and field studies to be one potential source of organic mass. We deployed a BBCES instrument to measure glyoxal during summer 2010 in Pasadena, California. We used three methods to quantify the contribution of glyoxal to aerosol in Los Angeles, and found that it accounts for only 0 - 4% of the secondary organic aerosol mass. Quantifying the optical properties of aerosols is important to understand their role in the Earth’s radiative budget. Previous measurements have indicated that brown carbon aerosol has a wavelength-dependent absorption that increases in the ultraviolet spectral region, and recent modeling suggests that this is an important component of aerosol radiative forcing. We have conducted recent laboratory and field measurements of aerosol scattering and absorption in the ultraviolet spectral region to address these issues.

Outing

Our Next Outing WIll Be Posted Soon.

University of Colorado Chapter
Sigma Xi
2013 Annual Reception and
Dr. Roy Henry Garstang Memorial Lecture

The 2013 Receptionn will be held on

April 22, 2013 in the UMC Aspen Rooms, University of Colorado Boulder

Please join us in celebrating our accomplishments, recognizing our new members, and award winner from the last year.

The 2013 Dr. Roy Henry Garstang Memorial Lecture

Will be presented by

Dr. Diane McKnight
Professor, INSTAAR- Institute, Arctic & Alpine Research

Title:
Climate Change and Water Quality in the Rocky Mountains: approaches for adapting to too much summer