DOI: 10.1594/pangaea.861229
title: The CCRUSH Study: Coarse and fine particulate matter measurements in northeastern Colorado 2009-2012

description: Coarse (PM10-2.5) and fine (PM2.5) particulate matter in the atmosphere adversely affect human health and influence climate. While PM2.5 is relatively well studied, less is known about the sources and fate of PM10-2.5. The Colorado Coarse Rural-Urban Sources and Health (CCRUSH) study measured PM10-2.5 and PM2.5 mass concentrations, as well as the fraction of semi-volatile material (SVM) in each size regime (SVM2.5, SVM10-2.5), for three years in Denver and comparatively rural Greeley, Colorado. Agricultural operations east of Greeley appear to have contributed to the peak PM10-2.5 concentrations there, but concentrations were generally lower in Greeley than in Denver. Traffic-influenced sites in Denver had PM10-2.5 concentrations that averaged from 14.6 to 19.7 µg/m**3 and mean PM10-2.5/PM10 ratios of 0.56 to 0.70, higher than at residential sites in Denver or Greeley. PM10-2.5 concentrations were more temporally variable than PM2.5 concentrations. Concentrations of the two pollutants were not correlated. Spatial correlations of daily averaged PM10-2.5 concentrations ranged from 0.59 to 0.62 for pairs of sites in Denver and from 0.47 to 0.70 between Denver and Greeley. Compared to PM10-2.5, concentrations of PM2.5 were more correlated across sites within Denver and less correlated between Denver and Greeley. PM10-2.5 concentrations were highest during the summer and early fall, while PM2.5 and SVM2.5 concentrations peaked in winter during periodic multi-day inversions. SVM10-2.5 concentrations were low at all sites. Diurnal peaks in PM10-2.5 and PM2.5 concentrations corresponded to morning and afternoon peaks of traffic activity, and were enhanced by boundary layer dynamics. SVM2.5 concentrations peaked around noon on both weekdays and weekends. PM10-2.5 concentrations at sites located near highways generally increased with wind speeds above about 3 m/s. Little wind speed dependence was observed for the residential sites in Denver and Greeley.
description: AmbRH = relative humidity in %AmbTemp = air temperature in °CACalc = Total (non-volatile+semi-volatile) PM2.5 mass concentrations in µg/m**3 calculated as (PM2.5_base - PM2.5_ref), raw refers to calculating concentrations using the method in the referenced papers instead of using the TEOM algorithm (i.e. raw includes no interpolated values during intervals in which base or reference wasn't measured), PM2.5_ref is a mass loss amount, which is why it is shown as negative mass concentrations and is subtracted from the base concentration to calculate the total concentration, though for data analysis purposes in the paper the time series was multiplied by -1.ACalcSE Standard error of ACalc per time interval (hourly or daily)ABase = PM2.5 non-volatile mass concentration in µg/m**3ABaseSE = Standard error of ABaseARef = PM2.5 semi-volatile mass concentration (described above) in µg/m**3, semi-volatile in context of the TEOM instrument means species that evaporate at 30 C from the filter surface (see paper for more details)ARefSE = Standard error of ARefBCalc, BCalcSE, BBase, BBaseSE, BRef, BRefSE = Same as above but for PM10-2.5PM10 = Particulate matter, &lt; 10 µm in µg/m**3PM10noFDMS = no FDMS means there is no semi-volatile species loss correction (ref terms above) applied by the instrument. This instrument is an older model which did not have an FDMS for making the semi-volatile mass loss correction..Data from sites not operated by the authors:COMM, WBY, CAMP, DMAS, GREH, GRET and CRG - EPA monitoring sites operated by CDPHENUN - NUNN #1 monitoring site operated by USDAI76/I70/I25/I270/CO257/US85/US34 - traffic count data from the Colorado Department of TransportationGREA - Greeley airport meteorological dataBRM - Broomfield airport meteorological data
description: Supplement to: Clements, Jeff C; Hannigan, Michael P; Miller, Shelly L; Peel, Jennifer L; Milford, Jana B (2016): Comparisons of urban and rural PM10-2.5 and PM2.5 mass concentrations and semi-volatile fractions in northeastern Colorado. Atmospheric Chemistry and Physics, 16(11), 7469-7484