Impact of Moderate Resolution Imaging Spectroradiometer Aerosol Optical Depth and AirNow PM2.5 assimilation on Community Multi-scale Air Quality aerosol predictions over the contiguous United States

摘要: In this study, Moderate Resolution Imaging Spectroradiometer (MODIS) Aerosol Optical Depth (AOD) and AirNow PM2.5 measurements are assimilated into the Community Multi-scale Air Quality (CMAQ) model using an optimal interpolation (OI) method. Over a 30 day test period in July 2011, three assimilation configurations were used which MODIS AOD first separately before being simultaneously. The background error covariance is estimated both National Meteorological Center approach Hollingsworth-Lonnberg observations from Terra at 17Z Aqua 20Z each day. 4 times day 00Z, 06Z, 12Z, 18Z. Model performances measured by daily averaged domain-averaged biases root-mean-square errors (RMSEs) obtained comparing predictions with that not assimilated. Either assimilating or alone helps over entire 30 days. case assimilates sources has best performance. While CMAQ results exhibit exaggerated diurnal variations compared to measurements, as severe rural sites urban suburban sites. It was also found total more beneficial for correcting underestimations than directly every 6 h. simple of applying scaling factors uniformly throughout vertical columns proved effective, it liable produce substantial errors. This demonstrated high-AOD event.