TITLE: ACEASIA_YulinRAD

AUTHOR(S): 

     Michael H. Bergin and Jin Xu
     200 Bobby Dodd Way, Atlanta, GA 30332
     Phone: 404-894-9723
     Fax: 404-894-8266 
     E-mail: mike.bergin@ce.gatech.edu, jin.xu@ce.gatech.edu

1.0 DATA SET OVERVIEW: 

     Aerosol light scattering coefficient, Bsp, at 530 nm, and absorption 
     coefficient, Bap, at 565nm of PM2.5 were measured at the Zhenbeitai 
     Aerosol Monitoring Station from 3/26/2001-5/1/2001. At the same time, 
     Bsp of total aerosols was measured.  Ambient temperature, pressure, 
     as well as sample and ambient RH were also monitored. 

2.0 INSTRUMENT DESCRIPTION: 

     Measurement	                        Instrument
     Aerosol Scattering Coefficient, 
          Bsp(TSP) (530 nm)	                Radiance Research Nephelometer
     Aerosol Scattering Coefficient, 
          Bsp(2.5) (530 nm), (Dp < 2.5 um)	Radiance Research Nephelometer
     Aerosol Absorption Coefficient, 
          Bap(2.5) (565 nm), (Dp < 2.5 um)	Radiance Research Particle Soot 
                                                Absorption Photometer (PSAP)
 
3.0 DATA COLLECTION AND PROCESSING: 

     The aerosol light absorption coefficient, sap, was measured at 565 nm 
     using a Radiance Research Particle Soot Absorption Photometer (PSAP). 
     The absorption coefficient was corrected for both light scattering 
     and instrument overestimation as described by Bond et al. (1999). Air 
     was sampled at a flow rate of 16.7 L/min at ambient temperature and 
     pressure through a URG Corporation cyclone inlet that removed 
     particles having diameters greater than 2.5 um, in order to sample 
     the particulate fraction that efficiently scatters light. The inlet 
     was located on the monitoring tower, and at a height ~10 m above the 
     ground surface. The air then passed through 2 m of 3/8 in. i.d. black 
     conductive tubing and into the instruments. The flow was split into 
     two separate sample streams using a URG Corporation flow splitter. A 
     portion of the flow (0.13 L min^-1) was sampled by the PSAP, with the 
     remaining flow going to the nephelometer. An additional sampling line 
     was operated at 8 L min^-1 at ambient temperature and pressure using a 
     Radiance Research nephelometer to sample total aerosols. Both 
     nephelometers have their own capacity-type RH / temperature sensors 
     (Vaisala, Inc. Humicap, model 50 Y) to measure the sample temperature 
     and RH. All of the flows were generated using a vacuum pump (Gast, 
     Inc.) and maintained by critical orifices manufactured by O'Keefe 
     Controls. Several times during the field study a HEPA capsule filter 
     was placed upstream of each sampling line in order to insure the 
     instruments were working properly. Typically, zero air Bsp values were 
     < 1 Mm^-1. 

4.0 DATA FORMAT: 

     Tab delimited ASCII

     Data were collected every minute, then hourly averaged data are 
     calculated and listed in the data file.

5.0 DATA REMARKS: 

     DATA VERSION = 1.0 (August 27, 2001), PRELIMINARY 
     REMARKS = Bap(2.5) and Bsp(2.5) are aerosol absorption at 565nm and 
               scattering coefficients at 530nm for PM2.5, respectively
     REMARKS=  Bsp(TSP) is aerosol scattering coefficient at 530 nm for 
               all aerosols
     REMARKS = w(2.5), single scattering albedo of PM2.5, equals 
               Bsp(2.5)/(Bap(2.5)+Bsp(2.5))
     REMARKS = Data point Date/Time provided in UTC, the data is hourly 
               averaged data

6.0 REFERENCES:

     Bond, T.C., T.L. Anderson, D. Campbell, Calibration intercomparison 
     of filter-based measurements of visible light absorption by aerosols, 
     Aerosol  Sci. Technol., 30, 582-600, 1999.