Measurements of Aerosol
Parameters
Aboard the DC-8 during TRACE-P
Bruce
E. Anderson, W. Randy Cofer, and Eddie L. Winstead
Atmospheric Sciences
Division, NASA Langley Research Center
We will
provide in situ measurements of aerosol size distribution, volatility, and
optical characteristics aboard the NASA DC-8 during the Transport and Chemical
Evolution over the Pacific (TRACE-P) mission.
The instrument suite will include: 1) a set of 3 condensation nuclei
counters to determine the number of particles between 0.003 and 0.012
mm
(ultrafine CN) and the volatility of aerosols > 0.012 mm;
2) a scanning mobility particle spectrometer (SMPS) to obtain 90-second
resolution size distributions for 0.010 to 0.250 mm
diameter particles; 3) two different, wing-tip mounted aerosol scattering
spectrometer probes for obtaining particle size distributions over the 0.1 to
20.0 mm size-diameter range; 4) a
3-wavelength, integrating nephelometer for measuring wavelength-dependent
aerosol extinction; 5) an aethelometer for determining total aerosol (i.e.,
black carbon) absorption; and 6) a cloud aerosol precipitation probe.
Table 1. DC-8
In Situ Aerosol Measurements
|
|
|
Size
Range |
Response |
|
DC-8 |
|
Measured
Parameter |
Instrument |
(microns) |
(seconds) |
Precision |
Pr |
|
Ultrafine
Aerosols |
TSI
3025, TSI 3760 |
0.004
- 0.012 |
1 |
20% |
3 |
|
Volatile,
Nonvolatile Aerosols |
TSI
3760 |
0.012
- 1.00 |
1 |
10% |
3 |
|
Ultrafine/Fine
Aerosol Size |
TSI
SMPS/TSI 3025 |
0.01
- 0.25 |
90 |
20% |
2 |
|
Fine,
Coarse Aerosol Size Distribution |
PMS
PCASP |
0.1
- 3.0 |
1 |
20% |
2 |
|
|
PMS
FSSP-300 |
0.4
- 20.0 |
1 |
20% |
2 |
|
|
DMT
CAPS |
0.3
- 50.0 |
1 |
10% |
2 |
|
Precipation
Particle Size Distribution |
DMT
CAPS |
25.0
- 1550 |
1 |
20% |
- |
|
Light
Scattering Coefficients at 450, |
TSI
3560 |
<
10 |
1 |
1
e-7/m |
3 |
|
550, and 700 nm |
|
|
|
|
|
|
Black
Carbon |
PSAP |
<
10 |
60
sec |
0.1
um/m3 |
3 |
|
Cloud
Liquid Water Content |
DMT
CAPS |
- |
1 |
.01
g/m3 |
- |
|
Particle
Refractive Index |
DMT
CAPS |
0.3
– 2 |
1 |
<
5% |
- |
Our
effort will include careful pre- and post-mission calibration of the instrument
payload; in-flight distribution of selected signals to the DC-8 data acquisition
and distribution system (DADS) for real-time display and use in flight planning;
generation of post-flight and post-mission data products; and post-mission
analyses aimed at evaluating the impact of Asian outflow upon tropospheric
aerosol loading and characteristics, and optical parameters over the western
Pacific.