Seminar
SPEAKER: Dan Lack, NOAA ESRL CSD and CU CIRES
TIME: Wednesday, February 4, 2009, 3:30 p.m.
PLACE: DSRC (NOAA Building) Room 2A-305, 325 Broadway, Boulder
DIRECTIONS: See http://esrl.noaa.gov/csd/seminars/
TITLE: Black, Brown and White Carbon. The complex interplay between sources, processing and optics of atmospheric particulate carbon.
ABSTRACT:
Black Carbon (BC) is of interest in the climate system because of its ability to absorb visible radiation and warm the atmosphere. It is estimated that BC has about 1/3 of the warming impact of CO2 and yet unlike CO2 BC has a very short atmospheric lifetime thus opening the door on warming mitigation for the short term. Sources and emissions of BC are uncertain, as are the optical properties which are known to change significantly as the BC is processed. Coating of BC with non-absorbing material can enhance absorption while collapse of fresh fractal BC can change the absorption. Recent studies have also identified some sources of organic carbon (so called brown carbon) as absorbers of visible radiation.
In this talk I will present an exploration of the complex interplay between the optics of black carbon and other organic material that is known to impact the optical properties of BC. This description will lead into a presentation of the instrument development, field deployments, recent publications, theoretical studies and future direction of research in our group at NOAA. The talk will focus on the efforts to reduce uncertainties in sources of BC, understanding limitation of existing data and the future in measuring the optical impact of atmospheric black, brown and white carbon.