%0 Journal Article %1 Qin:2004p120 %A Qin, Y %A Tonnesen, G %A Wang, Z %D 2004 %J Atmospheric Environment %K imported %N 19 %P 3069--3087 %R DOI 10.1016/j.atmosenv.2004.01.035 %T Weekend/weekday differences of ozone, NOx, Co, VOCs, PM10 and the light scatter during ozone season in southern California %U http://links.isiglobalnet2.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=mekentosj&SrcApp=Papers&DestLinkType=FullRecord&DestApp=WOS&KeyUT=000221548100013 %V 38 %X The weekend effect on ozone, a phenomenon with high ozone concentration at weekend, was analyzed using the data measured at 7 photochemical assessment monitoring stations (PAMS), (1) volatile organic compounds (VOCs) monitoring station and (2) routine ambient air quality monitoring stations in southern California during ozone season from 1995 to 2001. Weekend/week day differences of ozone, ozone precursors and PM10 concentrations and the light scatter, composition and reactivity of VOCs in morning traffic rush time and afternoon peak ozone time were compared. The possible causes for the weekend effect were discussed. The significant weekend effect was observed in southern California except in areas close to beach and far downwind direction from L.A. Downtown. On average, the peak O-3 and max 8 h average O-3 concentrations at weekend were 20% and 22%, respectively, higher than those on weekday while the concentrations Of 03 precursors and PM 10 and the light scatter were lower at weekday in southern California. In morning traffic rush time, the average concentrations of NOx, CO, NMOC and PM10 and the light scatter at weekend were about 37%, 18%, 15%, 14% and 9%, respectively, lower than those on weekday. In afternoon peak ozone time, the average concentrations of NOx, CO, NMOC and PM10 and the light scatter at weekend were about 29%, 13%, 24%, 17% and 17%, respectively, lower than those on weekday. The reactivities of VOCs in morning traffic rush time and afternoon peak ozone time at weekend were 17% and 26%, respectively, lower than those on weekday. VOCs sensitivity for ozone formation and a decrease NOx emissions at weekend can well explain the weekend effect in southern California. Less scatter of sunlight due to lower fine particle concentration at weekend results in enhanced ozone formation might be another possible cause for the weekend effect. (C) 2004 Elsevier Ltd. All rights reserved.

@article{Qin:2004p120, abstract = {The weekend effect on ozone, a phenomenon with high ozone concentration at weekend, was analyzed using the data measured at 7 photochemical assessment monitoring stations (PAMS), (1) volatile organic compounds (VOCs) monitoring station and (2) routine ambient air quality monitoring stations in southern California during ozone season from 1995 to 2001. Weekend/week day differences of ozone, ozone precursors and PM10 concentrations and the light scatter, composition and reactivity of VOCs in morning traffic rush time and afternoon peak ozone time were compared. The possible causes for the weekend effect were discussed. The significant weekend effect was observed in southern California except in areas close to beach and far downwind direction from L.A. Downtown. On average, the peak O-3 and max 8 h average O-3 concentrations at weekend were 20% and 22%, respectively, higher than those on weekday while the concentrations Of 03 precursors and PM 10 and the light scatter were lower at weekday in southern California. In morning traffic rush time, the average concentrations of NOx, CO, NMOC and PM10 and the light scatter at weekend were about 37%, 18%, 15%, 14% and 9%, respectively, lower than those on weekday. In afternoon peak ozone time, the average concentrations of NOx, CO, NMOC and PM10 and the light scatter at weekend were about 29%, 13%, 24%, 17% and 17%, respectively, lower than those on weekday. The reactivities of VOCs in morning traffic rush time and afternoon peak ozone time at weekend were 17% and 26%, respectively, lower than those on weekday. VOCs sensitivity for ozone formation and a decrease NOx emissions at weekend can well explain the weekend effect in southern California. Less scatter of sunlight due to lower fine particle concentration at weekend results in enhanced ozone formation might be another possible cause for the weekend effect. (C) 2004 Elsevier Ltd. All rights reserved.}, added-at = {2010-06-22T19:38:37.000+0200}, affiliation = {Qin, Y Univ Calif Riverside, Ctr Environm Res {\&} Technol, Coll Engn, 1084 Columbia Ave, Riverside, CA 92507 USA Univ Calif Riverside, Ctr Environm Res {\&} Technol, Coll Engn, Riverside, CA 92507 USA}, author = {Qin, Y and Tonnesen, G and Wang, Z}, biburl = {https://www.bibsonomy.org/bibtex/2e4be2ec5609cc6537e936e86b2a591ce/gsmith}, date-added = {2010-03-10 16:47:50 -0500}, date-modified = {2010-03-10 16:48:24 -0500}, doi = {DOI 10.1016/j.atmosenv.2004.01.035}, interhash = {2ff55ed9f753d4cebf2adc7c36910658}, intrahash = {e4be2ec5609cc6537e936e86b2a591ce}, journal = {Atmospheric Environment}, keywords = {imported}, label = {rec-number 1630}, local-url = {file://localhost/Users/geoffreysmith/Documents/Papers/Atmospheric%20Environment/2004/Atmospheric%20Environment,%2038,%203069-3087%202004.pdf}, month = Jun, note = {822NY Times Cited:22 Cited References Count:26}, number = 19, pages = {3069--3087}, pmid = {000221548100013}, rating = {0}, timestamp = {2010-06-22T19:39:32.000+0200}, title = {Weekend/weekday differences of ozone, NOx, Co, VOCs, PM10 and the light scatter during ozone season in southern California}, uri = {papers://E88B624E-D406-46FF-9D95-BB9C1AAE3FDC/Paper/p120}, url = {http://links.isiglobalnet2.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=mekentosj&SrcApp=Papers&DestLinkType=FullRecord&DestApp=WOS&KeyUT=000221548100013}, volume = 38, year = 2004 }