Title: C130 RCAD Aerosol Measurements

Contact:

  Lynn M. Russell
  Assistant Professor
  Department of Chemical Engineering
  Princeton University
  A319 Engineering Quadrangle
  Princeton, NJ, USA 08544
  E-Mail Address: lrussell@princeton.edu
  Tel: (609)258-1144
  Fax:(609)258-0211
  Secretary:(609)258-1830

Or

  Richard Flagan
  Department of Chemical Engineering
  California Institute of Technology
  Pasadena, CA  91125
  USA
  E-Mail Address: flagan@cheme.caltech.edu

Or

  John Seinfeld
  Department of Chemical Engineering,
  California Institute of Technology
  Pasadena, CA  91125
  USA
  E-Mail Address: john_seinfeld@starbase1.caltech.edu


Data Set Description:

[data updated December 1998]

Investigators: Lynn Russell, Richard Flagan and John Seinfeld

These data are made available in the ACE-1 archive as per the ACE1 data
sharing agreement, and use of these data is subject to those guidelines.

Radially-Classified Aerosol Detector (RCAD) Measurements

The data included here are an updated version of the preliminary data.
New data was received in December 1998. No data released at this time
should be considered final, and consequently users are advised to contact
us for updated corrections before using or submitting these data.

This instrument counted size-classified aerosols in the range 0.005 to
0.15 microns during the ACE1 experiment.  The instrument was operated
with a flow split of 8.3 cc/s (aerosol) and 83 cc/s (sheath), recording 36
channels of data in 45 seconds, for a voltage range of 9 to 5000 volts.


Format:

The data are in ASCII text format.  The first column lists the diameter
(in micrometers).  The second column lists the normalized particle
concentration, dn/dlogDp (in particles per cm3).

Each of the files included here contains the 45 channels of data describing a
single size distribution.  The name of the file gives the date and time of the
size distribution (JDT, first 3 digits give the Julian date, between 312
and 357).  To obtain size distributions, the following parameters describe
the operating parameters for the transfer function used in the data inversion:

(Tau)_c = 1 s [counting time for one channel of data]
      n = 45 channels [number of channels for each ramp]
(Tau)_s = 1.1 s [characteristic mixing time for DMA-CPC configuration]
(Tau)_p = 8 s [characteristic plumbing time for DMA-CPC configuration]
    Q_c = Q_m = 83 cc/s [sheath flow rate for DMA]
    Q_a = Q_s = 8.3 cc/s [sample flow rate for DMA]
  Q_cpc = 16.6 cc/s [CPC flow rate]
    Q_d = 8.3 cc/s [flow rate of dilution air]

The appropriate kernel function for inverting these data is described in L.M.
Russell, M.R. Stolzenburg, S.H. Zhang, R. Caldow, R.C. Flagan, and J.H.
Seinfeld, J. Atmos. Ocean. Tech., 1996 (June).  The
algorithm recommended in that work for performing the inversion is
MICRON (J.K. Wolfenbarger and J.H. Seinfeld, J. Aerosol Sci., 1990).


File Name Conventions:

This directory is divided into subdirectories by julian day.
Each julian day subdirectory contains the data for that day
in files named JJJnnnn.dat where JJJ is the julian day
and nnnn is the time.

An example for Julian day 310 at 6639 (Julian decimal date 310.6639)
is 3106639.dat in the subdirectory 310.


References:
  L.M. Russell, M.R. Stolzenburg, S.H. Zhang, R. Caldow, R.C. Flagan, and J.H.
      Seinfeld, J. Atmos. Ocean. Tech., 1996 (June). (J.K. Wolfenbarger and
      J.H. Seinfeld, J. Aerosol Sci., 1990).