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The first two data sets include particle number-size distributions in the
diameter range of 0.020 to 0.8 micrometers Stokes diameter made with an "Aitken"
DMPS (20 to 200 nm) and an "Accumulation" DMPS (200 to 800nm). All measurements
were made at a relative humidity of not more than 25%. The distributions have
been cleaned of all data from times of instrument malfunction or calibration.
Additionally, the data set with “filter” in the name contains only those
distributions where the total CN concentrations were stable over the course of
each measurement have been included.
files: ICEALOT_nsd_dmps_vX.csv ICEALOT_nsd_dmps_filter_vX.csv
The second two data sets include particle number-size distributions in the
diameter range of 0.96 to 10 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 not more than 25%. The APS data have been cleaned exactly
like the DMPS files described above.
file: ICEALOT_nsd_aps_vX.csv ICEALOT_nsd_aps_filter_vX.csv
The third two data sets include particle number-size distributions in the
diameter range of 0.020 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 DMPS channel was 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. Finally, the
regridded distributions were cleaned to eliminate values at the larger sizes
from the APS where “phantom” counts resulted in a spurious coarse mode in the
surface and volume distributions. All measurements were made at a relative
humidity of not more than 25%.
file: ICEALOT_nsd_dmps_aps_vX.csv ICEALOT_nsd_dmps_aps_filter_vX.csv
The fourth two data sets include particle number-size distributions in the
diameter range of 0.020 to 10 micrometers Stokes diameter as described in the
previous section that have been shifted to ambient temperatures and humidities.
The growth factors were calculated from measured chemistry with the same model
used for calculating the densities. The distributions were shifted and then
regridded onto a common set of diameters as described above.
file: ICEALOT_nsd_dmps_aps_ambient_vX.csv
ICEALOT_nsd_dmps_aps_ambient_filter_vX.csv
The fifth two data sets include particle mass-size distributions in the
diameter range of 0.020 to 10 micrometers Stokes diameter, calculated from the
number-size distributions described in the section 3 above. The conversion of
number to mass was done using densities calculated from measured chemistry.
(download only – not available for plotting)
file: ICEALOT_msd_dmps_aps_vX.csv ICEALOT_msd_dmps_aps_filter_vX.csv
The sixth two data sets include particle mass-size distributions in the
diameter range of 0.020 to 10 micrometers Stokes diameter at ambient temperature
and RH, calculated from the number-size distributions described in the section 4
above. The conversion of number to mass was done using densities calculated from
measured chemistry. (download only – not available for plotting)
file: ICEALOT_msd_dmps_aps_ambient_vX.csv
ICEALOT_msd_dmps_aps_ambient_filter_vX.csv
keyword |
description |
---|---|
nsd |
number size distribution |
msd |
mass size distribution |
ambient |
at ambient temperature and RH |
filter |
cleaned of periods where the CN concentrations were not stable |
Table 1: Filename keywords
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 |
---|---|---|
19-Mar-2008 | 23-Apr-2008 | ICEALOT_nsd_dmps_v1.csv |
19-Mar-2008 | 23-Apr-2008 | ICEALOT_nsd_dmps_filter_v1.csv |
19-Mar-2008 | 23-Apr-2008 | ICEALOT_nsd_aps_v1.csv |
19-Mar-2008 | 23-Apr-2008 | ICEALOT_nsd_aps_filter_v1.csv |
19-Mar-2008 | 23-Apr-2008 | ICEALOT_nsd_dmps_aps_v1.csv |
19-Mar-2008 | 23-Apr-2008 | ICEALOT_nsd_dmps_aps_filter_v1.csv |
19-Mar-2008 | 23-Apr-2008 | ICEALOT_nsd_dmps_aps_ambient_v1.csv |
19-Mar-2008 | 23-Apr-2008 | ICEALOT_nsd_dmps_aps_ambient_filter_v1.csv |
19-Mar-2008 | 23-Apr-2008 | ICEALOT_msd_dmps_aps_v1.csv |
19-Mar-2008 | 23-Apr-2008 | ICEALOT_msd_dmps_aps_filter_v1.csv |
19-Mar-2008 | 23-Apr-2008 | ICEALOT_msd_dmps_aps_ambient_v1.csv |
19-Mar-2008 | 23-Apr-2008 | ICEALOT_msd_dmps_aps_ambient_filter_v1.csv |
U.S.Dept of Commerce / NOAA / OAR / PMEL / Atmospheric Chemistry