atmospheric science programs and research unr has both undergrad and grad programs in atmospheric...
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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.
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.
Places We Work
Burning Brazilian Forest near Ji Parana: PyrocumulusClimate impacts of large scale biomass burning aerosol.
Courtesy Michael Welling, SMOCC 2002, Sept 25
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)
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:10.1029/2005JD005964.
0.5 to 1 km thick
Example of a morning when the Mexico City Plume Goes South to Popocatepetl Volcano, hiding it.
near forward scattering by particlessca = 30 degrees
r << r ~ r >>
Dynamometer Vehicle Tests: How much does your car pollute?
Jet Exhaust: SERDP 2002, North Island CA
The Crew In Action, 1,600’ underground in a Nevada
Gold Mine…
Undergrad physics major Ian Arnold, and Arnott
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.
Example of our Atmospheric Research: Optics of woodsmoke from different
sources
The Fire Science Laboratory in Missoula Montana
DUAL WAVELENGTH PHOTOACOUSTIC INSTRUMENT, PATENTED AND LICENSED TO DMT, BOULDER CO.
Measurement of Light Absorption, Scattering, and Extinction with a Single Instrument
Wood Smoke Particles by Rajan Chakrabarty, DRI/UNR Graduate Student
Fire Science Laboratory, Missoula Montana.
• Instrumentation sampling wood smoke during FLAME Chamber burns
• Photoacoustic instruments
UNR AND COLORADO STATE
UNIVERSITY STUDENTS AND
FACULTY
Fuel Fuel Characterization Burn (Label)
Ponderosa Pine, dried needles and sticks conifer (pine) A, C
Lodge pole Pine, needles and twigs conifer (pine) L
Utah Juniper, foliage and sticks conifer (pine) I
Southern Pine, needles conifer (pine) P
Ponderosa Pine duff duff (pine) F
Alaskan Duff (feather moss) duff G
Southern California Manzanita flowering shrub H
Southern California Chamise flowering shrub B, D, N
Southeastern Wax Myrtle flowering shrub O
Utah Sage and Rabbitbrush, foliage and sticks flowering shrub J
Southern California Ceanothus flowering shrub S
Southeastern US Palmetto, leaves miscellaneous flowering plant R
Asian Rice Straw (Taiwan) miscellaneous flowering plant E
Puerto Rico Fern fern M
(Puerto Rico mixed woods) Q
(Lignin) K
Chamise
Rice Straw
Ponderosa Pine
The fuels burned
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
Optical Parameters for Analysis of Absorption and Scattering
• Ångström exponent of absorption, b
babs β 1∝⎟⎠⎞⎜
⎝⎛
⎟⎠⎞⎜
⎝⎛
=⎟⎠⎞⎜
⎝⎛
2
1
2
1
2
1
ln
)()(ln
λλ
λβλβ
λλ abs
abs
b
– Common assumption of Ångström exponent model: for Black Carbon b=1
– Diesel Soot: b=1
– Rice Straw: b(405/870)=2.8
W. P. Arnott, AAAR tutorial, Sept. 2007 19
Ångström Exponent of Absorbtion vs.Single Scattering Albedo at 405 nm
0
0.5
1
1.5
2
2.5
3
3.5
0.3 0.4 0.5 0.6 0.7 0.8 0.9 1ù (405 nm)
Ponderosa Pine,mixed fuels
Chamise
Rice Straw
Ponderosa Pine Duff
Alaskan Duff
So. CalifornianManzanita
Sage & Rabbitbrush
Lodgepole Pine,mixed fuels
Utah Juniper,foilage/twigs
Puerto Rico Fern
Wax Myrtle,branches/foilage
Southern Pine,needles
Palmetto
Ceanothus
b(405/870)
Flowering Shrubs: Chamise, Manzanita, Sage & Rabbitbrush
Fern (Puerto Rico), Rice Straw & Ceanothus (a flowering shrub)
Duff: Alaskan & Ponderosa Pine Duff
Pines: Southern Pine, Lodgepole Pine, & Ponderosa Pine
ω