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 iority

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.