1. Atmospheric Science Programs and Research
UNR has both undergrad and grad programs in Atmospheric Science.
Prof. Arnott (Physics) and 25 faculty members from the Division of Atmospheric Sciences at the Desert Research Institute participate in the program.
The programs have a very strong research emphasis.
Areas of emphasis:
Atmospheric Physics, solar and infrared radiation transfer, cloud microphysics, instrumentation development. Solar and wind energy.
Atmospheric Chemistry, trace detetction of organic and inorganic air pollutants; Pollutant transport and evolution.
Meteorology and Climatology, Western regional climate center, Center for Climate and Fire Applications, local, regional, and global climate change.

2. Students of ATMS 360, Atmospheric Instrumentation, measuring the downwelling infrared radiation from the atmosphere. The strong emission around 650 cm-1 is due to CO2 in the atmosphere.

3. Places We Work

4. Courtesy Michael Welling, SMOCC 2002, Sept 25
Burning Brazilian Forest near Ji Parana: Pyrocumulus Climate impacts of large scale biomass burning aerosol.
Courtesy Michael Welling, SMOCC 2002, Sept 25 4

5. Pancakes Layers of Smoke from Siberian Forest Fires Observed Over North Central Oklahoma, 27 May 2003 (Photo by Roy Woods, the CIRPAS Twin Otter Co-pilot)
0.5 to 1 km thick
Photo courtesy of the CoPilot, Roy, on the aircraft.
Arnott, W. P., J. W. Walker, H. Moosmüller, R. A. Elleman, H. H. Jonsson, G. Buzorius, W. C. Conant, R. C. Flagan, and J. H. Seinfeld, (2006). Photoacoustic insight for aerosol light absorption aloft from meteorological aircraft and comparison with particle soot absorption photometer measurements: DOE Southern Great Plains climate research facility and coastal stratocumulus imposed perturbation experiments. Journal of Geophysical Research 111, D05S02, doi: /2005JD 5

6. near forward scattering by particles sca = 30 degrees
Example of a morning when the Mexico City Plume Goes South to Popocatepetl Volcano, hiding it.
near forward scattering by particles sca = 30 degrees
r << r ~  r >>  6

7. Dynamometer Vehicle Tests: How much does your car pollute?

8. Jet Exhaust: SERDP 2002, North Island CA

9. The Crew In Action, 1,600’ underground in a Nevada Gold Mine…
Undergrad physics major Ian Arnold, and Arnott

10. Vehicle Used for the Tests
Photograph showing the haul truck in operation along with the air quality samplers. The photoacoustic EC instrument is housed in the vanilla colored box on the equipment rack and the Dustrak nephelometers are in blue. The filter samplers are up on the wall immediately to the right of the blue writing on the wall. The sample inlet for the photoacoustic instrument can be seen draped over the top of the laptop computer.

11. Example of our Atmospheric Research: Optics of woodsmoke from different sources

12. The Fire Science Laboratory in Missoula Montana

13. Measurement of Light Absorption, Scattering, and Extinction with a Single Instrument
DUAL WAVELENGTH PHOTOACOUSTIC INSTRUMENT, PATENTED AND LICENSED TO DMT, BOULDER CO. 13

14. Wood Smoke Particles by Rajan Chakrabarty, DRI/UNR Graduate Student
Fire Science Laboratory, Missoula Montana.

15. UNR AND COLORADO STATE UNIVERSITY STUDENTS AND FACULTY
Photoacoustic instruments
Instrumentation sampling wood smoke during FLAME Chamber burns

16. Chamise
The fuels burned
Rice Straw
Ponderosa Pine

17. Optical Parameters for Analysis of Absorption and Scattering
Single Scattering Albedo, ω
Ratio of Scattering to Extinction
Dark, absorbing aerosol: ω<0.5
Diesel Soot: ω(550 nm)=0.3
“White”, highly scattering aerosol: ω>0.85
Rice Straw fuel: ω(405 nm)=0.88 17

18. Optical Parameters for Analysis of Absorption and Scattering
Ångström exponent of absorption, b
Common assumption of Ångström exponent model: for Black Carbon b=1
Diesel Soot: b=1
Rice Straw: b(405/870)=2.8 18

19. W. P. Arnott, AAAR tutorial, Sept. 2007
Duff: Alaskan & Ponderosa Pine Duff
Fern (Puerto Rico), Rice Straw & Ceanothus (a flowering shrub)
Flowering Shrubs: Chamise, Manzanita, Sage & Rabbitbrush
Pines: Southern Pine, Lodgepole Pine, & Ponderosa Pine 19
W. P. Arnott, AAAR tutorial, Sept. 2007 19