<?xml version="1.0" encoding="UTF-8"?><xml><records><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Gordon, Mark</style></author><author><style face="normal" font="default" size="100%">Staebler, Ralf M.</style></author><author><style face="normal" font="default" size="100%">Liggio, John</style></author><author><style face="normal" font="default" size="100%">Li, Shao-Meng</style></author><author><style face="normal" font="default" size="100%">Wentzell, Jeremy</style></author><author><style face="normal" font="default" size="100%">Lu, Gang</style></author><author><style face="normal" font="default" size="100%">Lee, Patrick</style></author><author><style face="normal" font="default" size="100%">Brook, Jeffrey R.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Measured and modeled variation in pollutant concentration near roadways</style></title><secondary-title><style face="normal" font="default" size="100%">ATMOSPHERIC ENVIRONMENT</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">2012</style></year><pub-dates><date><style  face="normal" font="default" size="100%">SEP</style></date></pub-dates></dates><volume><style face="normal" font="default" size="100%">57</style></volume><pages><style face="normal" font="default" size="100%">138-145</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">This paper presents a study of the evolution of particles and gases downwind of a highway, with a focus on the diurnal variation of pollutant gradients and its controlling variables. A mobile laboratory was used to measure the concentration gradients of ultra-fine particles (UFP), black carbon (BC), CO2, NO, and NO2 at varying distances up to 850 m from a major highway. The horizontal distributions of pollutants show a strong diurnal pattern. Results suggest that the horizontal gradients are predominantly influenced by traffic levels, friction velocity, and atmospheric stability. The results were compared to a dispersion model, which showed good agreement with the measurements and was able to qualitatively capture the observed diurnal cycles. Emission rates [g km(-1)] calculated from the model fits are within 10% of the Mobile 6.2C inventory for CO2 and demonstrate good agreement for NOx, but are higher than the inventory by a factor between 2.0 and 5.9 for black carbon. Hourly NOx emission rates correlate with the fraction of heavy-duty vehicles in the total fleet and agree with inventory values based on maximum vehicle emission rates. Crown Copyright (C) 2012 Published by Elsevier Ltd. All rights reserved.</style></abstract></record></records></xml>