Index of /arm-iop-file/2022/hou/tracer-ufi/collins-smps

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[TXT]ARM0739.Ambient_PSD.20230407_14_04_67.txt2023-04-10 19:22 4.6M 
[TXT]ARM0739.Ambient_PSD_time.20230407_14_04_45.txt2023-04-10 19:22 70K 
[TXT]ARM0739.Chamber_NPF_fits.20230407_14_04_82.txt2023-04-10 19:22 94K 
[TXT]ARM0739.Chamber_PSD.20230407_14_04_84.txt2023-04-10 19:22 4.1M 
[TXT]ARM0739.Chamber_PSD_time.20230407_14_04_83.txt2023-04-10 19:22 73K 
[TXT]ARM0739.Chamber_injected_particles_fits.20230407_14_04_80.txt2023-04-10 19:22 59K 
[TXT]ARM0739.PSD_Dp.20230407_14_04_96.txt2023-04-10 19:22 675  

Particle size distributions from TRACER-UFI

Overview:

Particle size distributions using a custom-built SMPS.  The measurements were made at the AMF-1 site in La Porte, TX between July 15, 2022 and August 30, 2022.  The SMPS alternated between sampling ambient air and that in the portable Captive Aerosol Growth and Evolution (CAGE) chamber.  The distributions from those two sources are separated.  

Metadata Creator:
Name: Don Collins
Email: donc@ucr.edu Phone: (951) 827-8536
Street: 1084 Columbia Ave City: Riverside
State: CA Postal: 92507
Contact Info:
Name: Don Collins
Email: donc@ucr.edu Phone: (951) 827-8536
Street: 1084 Columbia Ave City: Riverside
State: CA Postal: 92507
Investigator(s): Don Collins (donc@ucr.edu) 0000-0002-0010-290X
Xuanlin Du (xdu032@ucr.edu)
Data Format:ascii
File Naming Convention:Described in "Please describe how to use the data" above.
Abstract:

Particle size distributions using a custom-built SMPS.  The measurements were made at the AMF-1 site in La Porte, TX between July 15, 2022 and August 30, 2022.  The SMPS alternated between sampling ambient air and that in the portable Captive Aerosol Growth and Evolution (CAGE) chamber.  The distributions from those two sources are separated.  
Purpose:

The measurements were made as part of the TRACER-UFI project led by Jim Smith from University of California Irvine.  The objective of the study was to understand the precursors and chemistry responsible for formation and growth of ultrafine particles in the study region.  At nighttime when particle formation was not expected (or observed) in the chamber, ~30 nm ammonium sulfate particles were injected as seed particles to monitor secondary aerosol production rates.  Those injections were stopped just before sunrise.  New particle formation and growth events were commonly observed around mid-morning.  
Data Usage:The particle size distributions have 75 size bins centered at 0.0133 to 0.391 micrometers. The bin diameter array in micrometers is provided in the file PSD Dp.txt. Size distributions were measured approximately every 8 minutes. Because the measurements alternated between sampling chamber air and ambient air, the measurement time frequency in each of the two (chamber and ambient) datasets is not uniform. The midpoint time of the measurements is reported in Epoch (UTC) time in the Ambient PSD time.txt and Chamber PSD time.txt files. The particle size distributions are in dN/dlogDp (cm^-3) and saved in the files Ambient PSD.txt and Chamber PSD.txt. Each column corresponds to a diameter bin and each row corresponds to a measurement time. The size distributions measured in the chamber were fitted using one or more lognormals and the parameters of those fits are provided in separate files. The Chamber NPF fits.txt file contains fits of distributions measured during daytime when no particles were injected and particle formation and growth events were common. The Chamber injected particles fits.txt file contains fits of distributions measured at nighttime when 0.025 micrometer monodisperse particles were continuously injected. The four columns are time (Epoch, UTC), lognormal fit concentration in cm^-3, lognormal fit diameter in micrometers, and lognormal fit geometric standard deviation.
Arm Sites: hou
Content Time Range: Begin: 2022-07-15 End: 2022-08-30
Data Type:research data - ASR funded
Scientific Measurements(s):
Measurement nameVariables
Particle size distribution
Data Quality:
Attribute Accuracy: No formal uncertainty assessments were conducted and no estimates of uncertainty are reported.
Positional Accuracy: No formal positional accuracy tests were conducted
Consistency and Completeness Report: Data set is considered complete for the information presented, as described in the abstract. Users are advised to read the rest of the metadata record carefully for additional details.
Use Restrictions: No use constraints are associated with this data.
Distribution Info:
Organization Name: ARM Archive User Services
Email: armarchive[at]ornl.gov Phone: 1-888-ARM-DATA
Street: Oak Ridge National Laboratory City: Oak Ridge
State: Tennessee Postal: 37831-6290