Our next 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.

Lunch

Please fell free to join other Sigma Xi members for lunch on the ground four of the NCAR Mesa Lab at11:30 AM.

Up Coming Lunch Talks:

TBA

Security for events at NOAA

Presentations begin at 12:15PM in DSRC GC402 in the Skaggs Building of NOAA. You are welcome to join other Sigma Xi members and friends for lunch at 11:30AM in the cafeteria on the ground floor. The NOAA facility is a secured space. To enter the federal property on S. Broadway, you must get your name on an attendance list. Please indicate to Zdenka Smith that you plan to attend by calling her at 303 497-3051 or sending an e-mail message to: Zdenka.Smith @noaa.gov. Please respond even if you are uncertain about attending, so that your name is on the attendance list. There is only one entrance to the federal facility just south of the traffic light at 27 St. and Broadway. You will have to identify yourself to the security personnel at the entrance building. Then, ask for directions to the Skaggs building parking lot on the west side of the Skaggs Building. Please enter through the main entrance (facing west into the lower parking lot). You will have to be checked in by the security person at the desk in the entry lobby. Foreign nationals should call Zdenka Smith at the number above for special instructions.