Upload
bjorn
View
31
Download
0
Tags:
Embed Size (px)
DESCRIPTION
ICARTT 2004 Ronald H. Brown – Measurements Relevant to Aerosol Direct Radiative Forcing. Regional Assessment of Aerosol Direct Radiative Forcing - M EASUREMENTS. Measurements: Sub-1 m m particles Cavity Ring Down Extinction Cell Aerosol extinction & f(RH) (66% / 30%) continuous - PowerPoint PPT Presentation
Citation preview
ICARTT 2004Ronald H. Brown – Measurements Relevant to
Aerosol Direct Radiative Forcing
Regional Assessment of Aerosol Direct Radiative Forcing -
MEASUREMENTSCATEGORY Measured Parameters Platform
Aerosol Chemical Composition
Anions and cationsElemental carbon (EC)Organic carbon (OC)Organic carbon (speciated)Trace elements
RHB, P3, CPRHBRHB, P3, CPRHB, CPRHB
Aerosol Physical and Optical Properties
Number vs size, accumulation &coarse modesAbsorption (450, 550, 700 nm)Scattering & backscattering (450, 550, 700 nm)f(RH)Lidar backscatter profiles
RHB, P3RHB, P3, CPRHB, P3, CPRHB, P3RHB, NOAA-RS, CP
Radiative Properties Aerosol Optical Depth (spectral)Radiative fluxes, solar and longwave, upwelling and downwelling (spectral)Direct, diffuse, and total irradiances (spectral where possible)Surface albedo
RHB, NASA-RS, MISRNASA-RS, MISR
P3, NASA-RS
NASA-RS
Meteorological Parameters Wind speed, direction, RH, T, pressure, cloud type and amount, visibility
RHB
Measurements: Sub-1 m particles
• Cavity Ring Down Extinction Cell Aerosol extinction & f(RH) (66% / 30%) continuous
plus humidity scans
• HumidographAerosol scattering & f(RH)
humidity scans (increasing and decreasing RH)between 35 and 90% RH
• Aerosol composition Aerodyne Mass Spectrometer, PILS, impactors
SO4=, NO3-, NH4+, POM, EC, Trace elements
1.7
1.6
1.5
1.4
1.3
1.2
1.1
1.0
Ext
inct
ion
(M
m-1
)
807060504030DOY
Extinction Humidogram"Upper Branch"
1.7
1.6
1.5
1.4
1.3
1.2
1.1
1.0
f(R
H)
80706050%RH
Humidogram Upper Branch Lower Branch
RH RH
f(R
H)
f(R
H)
Comparison of Hygroscopic Growth Dependence of Aerosol Scattering from Humidified Nephelometer
and Extinction from CRDDOY 203 (12:00 UTC)
1.5
1.4
1.3
1.2
1.1
1.0
Ca
vity
Rin
g D
ow
n f
(RH
) (6
6%
/ 3
0%
)
0.80.70.60.50.40.30.2NR Organic Mass Fraction
195 - 280º Offshore Wind Sector
0.120.100.080.06
m44 / Organic Ratio
Dependence of f(RH) on aerosol composition
Comparison of Extinction Measured by Cavity Ring-down Extinction Cell and OPAL (LIDAR) at = 355 nm
280
260
240
220
200
180
160
140
120
100
Ex
tin
cti
on
a
t 3
55
nm
(M
m-1
)
198.40198.30198.20198.10
DOY
Opal_ExtinctionExtrapolated Data (CRD)
Ext @ 60% RH Ext @ 70% RH Ext @ 80% RH Ext @ 85% RH
Ext
inct
ion
(Mm
-1)
Ambient RH = 80 to 90%
0.8
0.6
0.4
0.2
0.0
AO
D
0.60.40.20.0AOD (s/n 5355)
1.2
1.0
0.8
0.6
0.4
0.2
0.0
AO
D
1.21.00.80.60.40.20.0
1.0
0.8
0.6
0.4
0.2
0.0
1.00.80.60.40.20.0
0.6
0.5
0.4
0.3
0.2
0.1
0.0
0.60.50.40.30.20.10.0AOD (s/n 5355)
380 nm 500 nm
675 nm 870 nm
s/n 3803 s/n 4080
y = 0.98x + 0.03
R2
= 0.99
y = 0.99x + 0.02
R2 = 0.99
y = 0.97x - 0.01
R2 = 0.98
y = 0.98x + 0.02
R2 = 0.98
y = 0.95x + 0.01
R2 = 0.96
y = 0.98x + 0.01
R2 = 0.95
y = 0.91x + 0.01
R2 = 0.91
y = 0.93x + 0.01
R2 = 0.89
Comparison of 3 Microtops Units for 380, 500, 675, 870 nm
1.2
1.0
0.8
0.6
0.4
0.2
0.0
AO
D (
s/n
3803
)
1.21.00.80.60.40.20.0AOD (s/n 4080)
y = 0.99x + 0.001
R2 = 0.99
Comparison of 2 Microtops Units for 440 nm
45
44
43
42
-71 -70 -69 -68 -67
0.8
0.6
0.4
0.2
0.0
AO
D (500 nm
)
RHB: Spatial Distribution of AOD measurements
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0.0
7/6/04 7/10/04 7/14/04 7/18/04 7/22/04 7/26/04 7/30/04 8/3/04 8/7/04 8/11/04GMT Date
400
300
200
100
0
1/M
m, 5
50 n
m
380nm 440nm 500nm 675nm 870nm
Can
adia
nF
ores
t Fire
s
Neph Sub-10 um Scattering
RHB: Time Series of Sub-10 um Scattering and AOD
J31Overflights
RHB: Time Series of Sub-10 um Scattering and AOD
1.0
0.8
0.6
0.4
0.2
0.0
3:00 PM7/11/04
4:00 PM 5:00 PM 6:00 PM 7:00 PM
GMT Date
100
80
60
40
20
0
1/M
m, 5
50 n
m
380nm 440nm 500nm 675nm 870nm
Canadian Forest Fires
Neph Sub-10 um Scattering
-2.0x10-3
-1.5
-1.0
-0.5
slo
pe
7/10 7/14 7/18 7/22 7/26 7/30 8/3 8/7GMT Date
1.2
0.8
0.4
0.0
AO
D, 5
00
nm
AOD = m* + b
Time series of AOD and spectral slope
Regions of higher AOD: Polluted, more small particles stronger spectral dependence
0.20
0.18
0.16
0.14
0.12
0.10
0.08
0.06
900800700600500400
1.2
1.0
0.8
0.6
marine, low AOD polluted, high AOD
Wang et al., JGR, 2003.
Used shipboard AOD measurementsto determine the accuracy of AOD retrievals from the GMS5 geostationary satellite.
Markowicz et al., JGR, 2003.
Used shipboard f(RH) measurementsto estimate the dependence of Surface and top of atmosphere forcing on RH.
Diurnally averaged aerosol forcingefficiencies determine from a radiative transfer model as a functionof RH.
Contacts:
f(RH): Tahllee Baynard, [email protected] Wang, [email protected]
Scattering, backscattering, absorption: Trish Quinn, [email protected]
Also available at http://saga.pmel.noaa.gov/data
AOD: Trish Quinn, [email protected] Also available at http://saga.pmel.noaa.gov/data