Beat Schmid et al. BAER Institute, Sonoma, CA Presented by Michael Box
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Transcript of Beat Schmid et al. BAER Institute, Sonoma, CA Presented by Michael Box
Airborne sunphotometer
measurements of aerosol in ACE-Asia
and their comparisons to
correlative measurements
Beat Schmid et al.BAER Institute, Sonoma, CA
Presented by
Michael BoxUniversity of New South Wales, Sydney
Hegg, D, Covert, D, Univ. of Washington, Atmospheric Sciences, WA
Hsu, C, Welton, E, GEST/UMBC, NASA Goddard Space Flight Center, Greenbelt, MD
Redemann, J, Bay Area Environmental Research, Institute, Sonoma, CA
Livingston, J , SRI, International, Menlo Park, CA
Russell P, NASA, Ames Research Institute, Moffett Field, CA
Wang, J, Flagan, R, Seinfeld, J, California Institute of Technology, Pasadena, CA
Bates, D, University of, Miami, Coral Gables, FL
Jonsson, H, CIRPAS, Marina, CA
Co-authors
Title
Slide 16
ACE-Asia Ob jectives:
Characterization: Determine the phy sical, che mical, andradiative properties of the m ajor aerosol types in the Ea stern A siaand Northwest Pacific region and inves tigate the relationshipsamong the se properties.
Radiation: Quant ify the interactions between aerosols andradiation in the Eastern Asia and Northwest Pacific region
Processes: Quant ify the phy sical and chemical p rocessescontrolling the evo lution o f the major aerosol types and inparticular of their phys ical, chemical, and radiative properties.
Make Observations to Improve Models of Aerosol Concentrations and Impacts.
Satellite, Ship and Aircraft Platforms in ACE-Asia
Groundbased observations
Lidars, aerosol chemistry & physics, optical properties, and radiation
AATS-6 AATS-14
NASA Ames Airborne Sunphotometers (AATS)
AOD (350-1558 nm) and H2O
C-130
Twin Otter
ACE-Asia C-130 Flight Tracks
C-130
Ron Brown Twin Otter
40
35
30
25
145140135130125120Longitude
Val
idat
ion
Validation of SeaWiFS AOD (Hsu et al. algo)
with AircraftSun photometer
Flying low over the ocean
AATS vertical profiles during ACE-Asia
AATS-14
AATS-6
In situ measurement of
Extinction =
Absorption
• Particle Soot Absorption Photometer (PSAP, =550nm)
• noisy (averaging)• low RH• Corrections
– scattering contribution
– inlet-cutoff (Da=8m)*
– correct to ambient RH*
Scattering
• Nephelometers = 450, 550, 700 nm, low RH = 550 nm, RH=20,60,85%
• Corrections– light source
– angular truncation (7°-170°)
– inlet-cutoff (Da=8m)*
– correct to ambient RH
+
*correction not required or done
Closure between airborne sunphotomter and in-situ
ACE-Asia Column ClosureLayer AOD
y = 0.826x + 0.0386
R2 = 0.6267
0
0.1
0.2
0.3
0.4
0.5
0 0.1 0.2 0.3 0.4 0.5
AATS-14
Nep
h+
PS
AP
ACE Asia Column ClosureAerosol Extinction
y = 0.8593x + 0.0116
R2 = 0.6004n = 2476
0
0.05
0.1
0.15
0.2
0.25
0.3
0.35
0.4
0 0.1 0.2 0.3 0.4
AATS-14
Ne
ph
+P
SA
P
Closure between airborne sunphotomter and in-situ for 9 profiles
In situ measurement of size distribution and computation of extinction
• Twin DMA, D=15-1000 nm (close to ambient RH)• Aerodynamic Particle Sizer, D=0.5 - 8 m (drier than ambient RH),
• adjust to ambient RH• compute extinction, needs m} needs composition
Wang et al. 2002, JGR (submitted)
Wang et al. subm. JGR, 2002
Closure experiment with airborne sunphotometer and lidar on ship
Ron Brown Twin Otter
R/V Ron Braun CIRPAS Twin Otter