Simulating PM concentration during a winter episode in a subtropical valley: Sensitivity simulations and evaluation methods Academic Article uri icon

abstract

  • We investigated a two-week episode with high PM concentrations in California Central Valley during the Christmas-New Year of 2000-2001 using a modeling system that consists of a computationally efficient, 3-D photochemical-microphysical transport model, a mesoscale meteorological model, emission models, and an evaluation package. One hundred simulations were conducted with fine resolutions and observational constraints, to reproduce spatial and temporal features of observed PM concentrations and to understand the formation mechanism of the episode. Simulated PM concentrations consist of secondary inorganic components, mainly ammonium nitrate, and total carbon in areas with elevated concentrations in the accumulation mode, and consist of mainly dust and sea salt in the coarse mode. Simulated oxidants and nitrate were significantly elevated over the valley, and the latter showed much less amplitude than the former. Simulated PM concentrations were evaluated with observations systematically with spatially and temporally paired method, a more restrictive multivariate method (NMFROC), and a more flexible "gradient evaluation" method. The paired evaluation shows that high correlation coefficient (R = 0.8) and low fractional error (FE = 0.1) could be achieved at stations with elevated 24-h concentration of PM in the accumulation mode in some simulations. The NMFROC method was used to extract useful information from seemingly failed simulations. A "gradient evaluation" method is introduced here to extract additional information from simulations. We found that emission reductions of NO x and AVOC showed similar effects on percentage basis in different areas, and both are more effective than reducing NH 3 for abating elevated concentrations of accumulation mode PM in California Central Valley during the winter episode.

published proceedings

  • ATMOSPHERIC ENVIRONMENT

altmetric score

  • 3

author list (cited authors)

  • Livingstone, P. L., Magliano, K., Guerer, K., Allen, P. D., Zhang, K. M., Ying, Q., ... Byun, D.

citation count

  • 9

complete list of authors

  • Livingstone, PL||Magliano, K||Guerer, K||Allen, PD||Zhang, KM||Ying, Q||Jackson, BS||Kaduwela, A||Kleeman, M||Woodhouse, LF||Turkiewicz, K||Horowitz, LW||Scott, K||Johnson, D||Taylor, C||O'Brien, G||DaMassa, J||Croes, BE||Binkowski, F||Byun, D

publication date

  • December 2009