PLEASE NOTE: These data are subject to revision.
The first data set includes particle number-size
distributions in the diameter range of 0.003 to 0.671 micrometers
Stokes diameter made with an ultrafine DMPS (to 25 nm) and a DMPS
(20 to 671nm). All measurements were made at a relative humidity of
The second file includes particle number-size distributions
in the diameter range of 0.5 to 20 micrometers aerodynamic diameter.
The APS diameters are aerodynamic and have not been corrected to
Stokes diameter via calculation or estimates of particle density.
The APS data larger than 10 micrometers are not useful due to
significant particle losses in the inlets including the ship's
sampling mast, distribution tubing and APS inlet. All measurements
were made at a relative humidity of 55%.
The third file includes particle number-size distributions in
the diameter range of 0.003 to 6.3 micrometers Stokes diameter. The
distributions are a combination of DMPS and APS data where the APS
data have been corrected for ultra-Stokesian conditions in the
instrument jet, corrected for shape effects and converted to Stokes
diameters. This conversion was done using densities calculated from
measured chemistry. The diameter channels in the overlap region were
chosen in the following manner: the last 2 DMPS channels were
discarded and, after converting to Stokes diameters, the first APS
diameter channel that was larger than the last valid DMPS channel
was chosen as the first APS channel. Each combined distribution was
regridded onto a common set of diameters. All measurements were made
at a relative humidity of 55%.
More information about these data can be found by clicking on the blue "Instrument Information" tab above.
The following files are available for downloading. Please note: one data file may cover more than one time period, thus,some files may be listed more than once. All files are in csv (comma separated value) format. After several lines of general information each file starts with a first row that contains the particle diameter in microns for that column. The first column contains the date/time in Day-of-Year, DOY. DOY 32.5 is 1200 noon UTC on 1-February. All data are in units of dN/dlog10(Dp), N/cm^3. Missing data are designated by a -99 or a -999.
|Start Date||End Date||ASCII file|
U.S.Dept of Commerce / NOAA / OAR / PMEL / Atmospheric Chemistry