From hsieveri@carbon.cudenver.edu Wed Jul 17 11:15:49 1996
Date: Wed, 10 Jul 1996 14:58:55 -0600 (MDT)
From: "Herman C. Sievering" 
To: ACE-1 Community 


SUMMARY STATEMENT:  CAPE GRIM AEROSOL CHEMICAL CHARACTERIZATION WORKING GROUP

Co-chairs:  Herman Sievering and Ann Middlebrook

Our tasks are:

Task A)  Compile aerosol chem. data, incl. gas phase species info. of 
significance to aerosol chem. char.  A tentative list of 
instrumentation/data which applies to this task is given below( Please 
comment/correct): 

SIZE-DISTRIBUTED BULK AEROSOL DATA

1) Moudi impactors' data -  U. of Hawaii( Huebert & Howell) version 
obtained from the 10-m stack( ~30-40m asl) under low RH( 35-40 %) 
conditions.  CSIRO( Ayers & Cainey) version obtained from roof( ~30-40m 
asl) at 30 C or < 50 % RH.

2) Sierra hivol impactor data -  U. of Colorado( Sievering & Slavich) 
obtained from 50m tower level( ~125m asl) under ambient RH( 76 +- 6 % 
during ACE-1 sampling) conditions.

3) "Gold Top" >1 um and <1 um dia. data -  CSIRO( Ivey and Ayers) 
obtained from roof under ambient conditions.

4) Filter pack >1 um dia. and <1 um data -  Bureau of Meteorology( Dick) 
obtained from base( ground level) of 10 cm dia. stainless steel tube w. 
inlet at 53-m tower level under ambient RH conditions.


SIZE-DISTRIBUTED INDIVIDUAL PARTICLE DATA

5) Laser Mass Spectrometry( PALMS) data - NOAA-Aeronomy Lab( 
Murphy/Middlebrook/Thomson)    Particles of >0.16 um dia. obtained from 
the 53-m inlet( ~130 m asl) at 60 +- 20 % RH( slightly lower than ambient).

6) Electron Microscopy( EM) analysis of EM grids( 4 size range grids per 
sample) along with Nucleopore filters under ambient RH conditions.  EM 
grids will be analyzed at Arizona St. Univ.( Posfai & Anderson) by TEM 
and electron diffraction; filters by SEM.  Samples obtained from 50-m 
level on tower.


HYGROSCOPIC GROWTH/LIGHT SCATTERING

7) Tandem Differential Mobility Analyzer( TDMA) data( Covert, U. of 
Washington) obtained from the 10-m stack at varying RH.  Dat will be 
analyzed to infer chemical composition.

8) Nephelometer data( Rood & Carrico, U. of Illinois) obtained from the 
10-m stack at 22%, 40%, and 82% RH with 1um and 10 um dia. cuts.  Data 
will be analzed to infer chemical properties of aerosol.


AEROSOL MASS

9) Moudi impactor data( Howell, U. of Hawaii).  Mass obtained under low 
RH conditions from the 10-m stack.

GAS PHASE SPECIES

10) Ammonia data( Whung, NOAA-AOML) obtained from ground level next to CG 
station.


Task B) - Identify consistencies/inconsistencies in the data.

1) determine intercomparison species, times, etc.  A prime time period is 
the 2nd ship intercomp. period when winds were favorable.  This period 
began on AM of J338 and continued thru J340.  Sea salt mode at CG appears 
to have varied by factor of 3, or more, at CG during this period w. 
widely varying RH also.

2) Use scatter plots as first step in comparisons.

3) Cainey/Ayers are unsure of the validity of nssSO4 data from roof/stack 
for 2 um dia. and larger aerosol.  They are reviewing their MOUDI data to 
ascertain all of the reasons why but local bluff sea spray/soil input is 
a candidate reason. 


Task C - Characterize aerosol chem. from viewpoint of met 
conditions/special events.

1) Baseline periods, 2nd ship intercomp., etc.( Ideas welcome)

2) Smmarize chem. char. of aerosols for each period.  


Please send comments to HSIEVERI@CARBON.CUDENVER.EDU
		     or AMIDDLEBROOK@AL.NOAA.GOV