S. C. Olsen

Publications (2)0 Total impact

• Source

  Available from: atmos-chem-phys.net

  Article: Comparisons of WRF/Chem simulations in Mexico City with ground-based RAMA measurements during the 2006-MILAGRO

  Zhang Y, M. K. Dubey, S. C. Olsen, Zheng J, Zhang R
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  ABSTRACT: Simulations using the fully coupled WRF/Chem (Weather Research and Forecasting – Chemistry) model at 3-km resolution in Mexico City have been performed to examine the temperature, relative humidity, wind, and gaseous criteria pollutants (CO, O3, NO, NO2, and NOy) during the MCMA-2006/MILAGRO field campaign. Comparison of the model simulations with measurements from the ground-based air quality monitoring network (RAMA) is presented. The model resolves reasonably well the observed surface temperature, relative humidity and wind speed; however, large discrepancies are identified between the simulated and the observed surface wind direction for wind speeds below 2 m s−1. The simulated chemical species concentrations (CO, O3, NO, NO2, and NOy) compare favorably with the observations. Simulated O3 concentrations agree especially well with the observations. The simulated 10 VOC species compare generally favorably with the observations at the T0 supersite although lower correlation coefficients and larger biases exist for propene, acetone and propanal, isoprene, and c10-aromatics when compared to the other VOC species. The model performs much better during daytime than nighttime for both chemical species and meteorological variables, although the model tends to underestimate daytime temperature and relative humidity. Simulations using combinations of the available PBL schemes and land surface models (LSMs) do not show a preferred combination in reproducing the observations. The simulated meteorological fields under the O3-South, O3-North and EI Norte weather episodes exhibit similar correlation coefficients and biases for the same variable. However, the model performs well for the O3-South episode but inferiorly for the El Norte events in resolving the observed chemical species.
  Atmospheric Chemistry and Physics. 01/2009;
• Article: Comparisons of WRF/Chem simulations in Mexico City with ground-based RAMA measurements during the MILAGRO-2006 period

  Zhang Y, M. K. Dubey, S. C. Olsen
  [show abstract] [hide abstract]
  ABSTRACT: Comparison of the WRF/Chem (Weather Research and Forecasting – Chemistry) model simulations at 3-km resolution with measurements from the ground-based RAMA monitoring network during the MCMA-2006/MILAGRO field campaign is presented. The model resolves reasonably well the observed surface temperature, relative humidity and wind speed; however, large discrepancies are identified between the simulated and the observed surface wind direction for wind speeds below 2 m s−1. The simulated chemical species concentrations (CO, O3, NO, NO2 and NOy) compare favorably with the observations with the notable exception of SO2. Simulated O3 concentrations agree especially well with the observations. The model performs much better during daytime than nighttime for both chemical species and meteorological variables, although the model tends to underestimate daytime temperature and overestimate nighttime relative humidity. It is noted that the simulated nocturnal planetary boundary layer (PBL) height using the Yonsei University PBL scheme is unrealistically low. However, no combination of the available PBL schemes and land surface models (LSMs) is distinctly better than the others in reproducing the observations. The simulated meteorological fields under the O3-South, O3-North and EI Norte weather episodes exhibit similar correlation coefficients and biases for the same variable. However, the model performs best for the O3-South episode and performs poorest for the El Norte events in resolving the observed chemical species.
  Atmospheric Chemistry and Physics Discussions. 01/2009;