Examination of the Community Multiscale Air Quality (CMAQ) model performance over the North American and European domains

Abstract

Copyright 2011 Elsevier B.V., All rights reserved.The CMAQ modeling system has been used to simulate the air quality for North America and Europe for the entire year of 2006 as part of the Air Quality Model Evaluation International Initiative (AQMEII). The operational model performance of tropospheric ozone (O), fine particulate matter (PM) and total particulate matter (PM) for the two continents has been assessed. The model underestimates daytime (8am-8pm LST) O mixing ratios by 13% in the winter for North America, primarily due to an underestimation of daytime O mixing ratios in the middle and lower troposphere from the lateral boundary conditions. The model overestimates winter daytime O mixing ratios in Europe by an average of 8.4%. The model underestimates daytime O by 4-5% in the spring for both continents, while in the summer daytime O is overestimated by 9.8% for North America and slightly underestimated by 1.6% for Europe. The model overestimates daytime O in the fall for both continents, grossly overestimating daytime O by over 30% for Europe. The performance for PM varies both seasonally and geographically for the two continents. For North American, PM is overestimated in the winter and fall, with an average Normalized Mean Bias (NMB) greater than -30%, while performance in the summer is relatively good, with an average NMB of -4.6%. For Europe, PM is underestimated throughout the entire year, with the NMB ranging from -24% in the fall to -55% in the winter. PM is underestimated throughout the year for both North America and Europe, with remarkably similar performance for both continents. The domain average NMB for PM ranges between -45% and -65% for the two continents, with the largest underestimation occurring in the summer for North American and the winter for Europe

The effects of global change upon United States air quality

“…7). Several factors contribute to the underestimation of PM 2.5 in the western US, including a lack of windblown dust and fire smoke emissions, and an underestimation of SOA formation (Carlton et al, 2010;Foley et al, 2010;Appel et al, 2012;Luo et al, 2011). Another important factor that influenced the underestimation of PM 2.5 is the overprediction of precipitation as shown in Fig.…”

Evaluation of the GEM-AQ model in the context of the AQMEII Phase 1 project

“…Also, Pirovano et al (2012) reported a strong underestimation of ozone concentrations during the first part of the year for CAMx and CHIMERE models. CMAQ results, described in Appel et al (2012), indicate that model performance for the daytime ozone varied seasonally. In the winter, CMAQ overestimated ozone concentration by 8 % and in the spring and summer ozone levels were underestimated on average by ∼ 4 and 2 % respectively.…”

“…In southern and eastern Europe, model results were underestimated. Appel et al (2012) reported that in winter the domain-averaged MBE is −21.5 µg m −3 for the CMAQ model. For other seasons the underestimation is lower -in the range of −11/ − 16 µg m −3 .…”

“…In terms of the correlation coefficient, the CHIMERE model performed well in southern, north-western and eastern Europe, while CAMx showed better results in eastern Europe. The CMAQ model (Appel et al, 2012) overestimated daytime ozone concentrations in the south-western part of the domain and underestimated the north-eastern part, including the British Isles, in winter. The largest overestimation occurred over northern Italy (Po Valley), while the largest underestimation was over the Czech Republic and Poland.…”

“…Evaluation of ozone predictions was presented by Solazzo et al (2012b). Appel et al (2012) presented and discussed results obtained with the Community Multiscale Air Quality (CMAQ) model using different boundary conditions. Brandt et al (2012) reported modelling results with the Danish Eulerian Hemispheric Model (DEHM).…”