|
|
 |
|
|
|
UBWOS2012 Aerosol Number size distribution
(Covert/Bates)
Horsepool, Utah
Aerosol Number-Size Distributions, 10 nm to 480 µm diameter
Version 0
PI contact information:
Timothy S Bates
OCRD
NOAA/PMEL
7600 Sand Point Way NE
Seattle, WA 98115
USA
Phone: 206-526-6248
Fax: 206-526-6744
E-Mail Address: tim.bates@noaa.gov
Or
David S Covert
University of Washington
Department of Atmospheric Science
Box 354235
Seattle, WA 98195
USA
206-685 7461
E-Mail Address:
dcovert@u.washington.edu
Or
Derek Coffman
NOAA/PMEL
7600 Sand Point Way NE
Seattle, WA 98115
USA
206-526-6574
206-526-6790
E-Mail Address:
derek.coffman@noaa.gov
Short Description:
The data files contain particle number-size distribution measured during UBWOS
2012. These are measured by an integrated system of SMPS and APS instrumentation
and presented as two files, one from the APS and one from the SMPS. The two data
files represent SMPS scans and APS averages over 2 minute intervals defined in
the data file. The measurement RH was dry (<25%).
Data were inverted, edited, and analyzed by the PIs at PMEL.
Keywords: number concentration, number-size distribution, ultrafine differential mobility particle sizer, differential mobility particle sizer, aerodynamic particle sizer, UDMPS, DMPS, APS, relative humidity
Full Description of data set:
DOY:
DOY is decimal day of year such that DOY 1.5 is 12 noon UTC on 1 January. The
DOY values are the start time of the scan period.
Particle number-size distributions, [N(Dp)], during UBWOS 2012:
Aerosol particles were sampled 13 m above the ground through a mast that extended 9.1 m above the aerosol measurement container. The mast was capped with an inverted-bowl rain shield. Air was drawn down the 20 cm diameter mast at 1 m3 min-1. A 5 cm diameter 2.3 m long stainless-steel pipe extended into the base of the mast. The pipe was heated to 9.75 ± 0.68°C to dry the aerosol to a relative humidity (RH) of <25%. At the base of the mast, the flow through the stainless steel pipe was split into four 1.6 cm diameter stainless-steel tubes and one 0.63 cm tube. The average temperature and RH in the sample line measured downstream of an impactor was 24.3 ± 1.9°C and 10.3 ± 3.9%, respectively.
The 0.63 cm diameter tube was used to supply ambient air to a scanning mobility particle sizer (TSI 3081 SMPS) connected to condensation particle counter (TSI 3010 CPC). Data were collected in 106 size bins from 11 to 478 nm. The SMPS was operated with a sample flow rate of 1.0 L/min and a sheath flow of 5 L/min The 0.63 cm diameter tube also supplied ambient air to an aerodynamic particle sizing (TSI 3321 APS). The APS data reported here are in 34 size bins with the nominal manufacturers aerodynamic diameters ranging from 0.96 to 10.37 µm. Data are reported in aerodynamic diameter (micrometers) in units of dN/dlogDp (cm-3).
Size distributions were collected every 2-minutes by the SMPS and the APS.
All data were filtered to eliminate periods of calibration and instrument malfunction. The value of -999 is assigned to any period without data.
The v0 data are given in two file types: SMPS size distributions where the sizes are geometric diameters and APS size distributions where the sizes are aerodynamic diameters.
Format: comma-delimited ASCII. DOY (Julian Decimal Date) (UTC) followed by the smps, aps size bins as described above. The first two rows of data contain the bin numbers and the midpoint diameters in micrometers of each bin, respectively.
Data can be downloaded in a comma delimited format (.csv).
U.S.Dept of Commerce / NOAA / OAR / PMEL / Atmospheric Chemistry