Size Distribution Data for: NEAQS 2002

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VESSEL: R/V RONALD H. BROWN  DEPARTED: Charleston, South Carolina on 12 July, 2002 ARRIVED: Portsmouth, New Hampshire on 26 July 2002 DEPARTED: Portsmouth, New Hampshire on 29 July 2002 ARRIVED: Charleston, South Carolina on 11 August 2002 Link to more NEAQS 2002 pages

• The first data sets include particle number-size distributions in the diameter range of 0.003 to 0.6 micrometers Stokes diameter made with an ultrafine DMPS (to 20 nm) and a DMPS (20 to 600nm). All measurements were made at a relative humidity of 55%. The data have been separated into legs 1 and 2. Additionally, the data are offered as filtered or unfiltered. The unfiltered data include all size size distributions (excluding periods of calibration). The filtered distributions show only those distributions where the total CN concentrations were stable over the course of each measurement.
  files: NEAQS2002_nsd_dmps_leg1.csv NEAQS2002_nsd_dmps_leg2.csv NEAQS2002_nsd_dmps_leg1_filter.csv NEAQS2002_nsd_dmps_leg2_filter.csv
• The second data sets include 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 APS data are given in the same types of files described above (legs 1 and 2, unfiltered and filtered).
  file: NEAQS2002_nsd_aps_leg1.csv NEAQS2002_nsd_aps_leg2.csv NEAQS2002_nsd_aps_leg1_filter.csv NEAQS2002_nsd_aps_leg2_filter.csv
• The third data sets include particle number-size distributions in the diameter range of 0.003 to 10 micrometers Stokes diameter. The distributions are a combination of DMPS and APS data where the APS data have been 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%. The files that have ambientRH in the filename contain distributions shifted to represent ambient conditions. The diameters were shifted using growth factors calculated from measured chemistry at the ambient temperature and RH. The growth factors were applied to the distributions at 55% RH and then regridded onto a common set of diameters. The DMPS/APS data are given in the same types of files described above (legs 1 and 2, unfiltered and filtered).
  file: NEAQS2002_nsd_dmps_aps_leg1.csv NEAQS2002_nsd_dmps_aps_leg2.csv NEAQS2002_nsd_dmps_aps_leg1_filter.csv NEAQS2002_nsd_dmps_aps_leg2_filter.csv NEAQS2002_nsd_dmps_aps_ambientRH_leg1.csv NEAQS2002_nsd_dmps_aps_ambientRH_leg2.csv

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.

U.S.Dept of Commerce / NOAA / OAR / PMEL / Atmospheric Chemistry