Pollutant transport among California regions

[1] Several regions within California have significant air quality issues. Transport of pollutants emitted in one region to another region may add to the impact of local emissions. In this work, Lagrangian particle dispersion model simulations show the amounts of tracers that are transported within and among four regions, Southern California, the San Francisco Bay Area, the Central Valley, and the rest of the state. The simulations cover May and June of 2010, the California Research at the Nexus of Air Quality and Climate Change experiment period. Tracers of automobile emissions and one type of agricultural emission are used. Tracer mixing ratios are compared to airborne and ground-based measurements. The age of tracers in each location is also presented. Vertical profiles and diurnal cycles help to clarify the transport process. As is well known, Southern California emissions are transported to the east and affect the desert areas, and Bay Area automobile emissions are an important source of pollutants in the San Joaquin Valley. A novel result is that the Southern California Bight is filled with a mixture of well-aged carbon monoxide tracer from Southern California and the Bay Area. Air over the Bight is also affected by the agricultural emissions represented by the agricultural tracer, dominantly from the Central Valley where its sources are largest. There is no indication of transport from Southern California to the Central Valley. Emissions from the Central Valley do make their way to Southern California, as shown by the agricultural tracer, but automobile emissions from the Valley are insignificant in Southern California.

[1]  G. Powers,et al.  A Description of the Advanced Research WRF Version 3 , 2008 .

[2]  Gregory J. Frost,et al.  Top-down estimate of surface flux in the Los Angeles Basin using a mesoscale inverse modeling technique: assessing anthropogenic emissions of CO, NOx and CO2 and their impacts , 2012 .

[3]  M. Fischer,et al.  Seasonal variation of CH4 emissions from central California , 2012 .

[4]  D. Edwards,et al.  CO source contribution analysis for California during ARCTAS-CARB , 2011 .

[5]  Stuart A. McKeen,et al.  Numerical uncertainty at mesoscale in a Lagrangian model in complex terrain , 2012 .

[6]  O. Cooper,et al.  Measurement of western U.S. baseline ozone from the surface to the tropopause and assessment of downwind impact regions , 2011 .

[7]  A. Stohl,et al.  Technical note: The Lagrangian particle dispersion model FLEXPART version 6.2 , 2005 .

[8]  Michael D. Moran,et al.  Evaluation of the meteorological forcing used for the Air Quality Model Evaluation International Initiative (AQMEII) air quality simulations , 2012 .

[9]  C. Gerbig,et al.  Accounting for the effect of transport errors on tracer inversions , 2005 .

[10]  Christopher W. Fairall,et al.  Meteorological Model Evaluation for CalNex 2010 , 2012 .

[11]  R. Banta,et al.  Long‐range transport of ozone from the Los Angeles Basin: A case study , 2010 .

[12]  Gabrielle Pétron,et al.  Top-down estimate of anthropogenic emission inventories and their interannual variability in Houston using a mesoscale inverse modeling technique , 2011 .

[13]  Zaviša I. Janić.  Nonsingular implementation of the Mellor-Yamada level 2.5 scheme in the NCEP Meso model , 2001 .

[14]  K. Suselj,et al.  Improving the Mellor–Yamada–Janjić Parameterization for wind conditions in the marine planetary boundary layer , 2010 .

[15]  V. Thouret,et al.  Observations of ozone transport from the free troposphere to the Los Angeles basin , 2012 .

[16]  J. Seinfeld,et al.  The 2010 California Research at the Nexus of Air Quality and Climate Change (CalNex) field study , 2013 .

[17]  J. Bao,et al.  Observed and WRF-Simulated Low-Level Winds in a High-Ozone Episode during the Central California Ozone Study , 2008 .

[18]  J. Dudhia,et al.  Coupling an Advanced Land Surface–Hydrology Model with the Penn State–NCAR MM5 Modeling System. Part II: Preliminary Model Validation , 2001 .

[19]  A. Palazoglu,et al.  Influence of synoptic and mesoscale meteorology on ozone pollution potential for San Joaquin Valley of California , 2009 .

[20]  John C. Lin,et al.  Vertical mixing in atmospheric tracer transport models: error characterization and propagation , 2007 .

[21]  J. Burrows,et al.  Evaluations of NOx and highly reactive VOC emission inventories in Texas , 2011 .

[22]  Marc L. Fischer,et al.  Where do fossil fuel carbon dioxide emissions from California go? An analysis based on radiocarbon observations and an atmospheric transport model , 2008 .

[23]  O. Cooper,et al.  Stratospheric influence on surface ozone in the Los Angeles area during late spring and early summer of 2010 , 2011 .

[24]  K. F. Boersma,et al.  Evaluations of NO x and highly reactive VOC emission inventories in Texas and their implications for ozone plume simulations during the Texas Air Quality Study 2006 , 2011 .

[25]  Ann M. Middlebrook,et al.  Ammonia sources in the California South Coast Air Basin and their impact on ammonium nitrate formation , 2012 .

[26]  M. Fischer,et al.  Observation of CH4 and other Non-CO2 Green House Gas Emissions from California , 2009 .

[27]  Linsey C Marr,et al.  Changes in motor vehicle emissions on diurnal to decadal time scales and effects on atmospheric composition. , 2005, Environmental science & technology.

[28]  J. Thepaut,et al.  The ERA‐Interim reanalysis: configuration and performance of the data assimilation system , 2011 .

[29]  H. Akimoto,et al.  Long‐range transport of ozone in the East Asian Pacific rim region , 1996 .

[30]  Regional transport of the urban workweek: Methylchloroform cycles in the Nevada‐Arizona Desert , 1990 .

[31]  Kevin W. Manning,et al.  The Integrated WRF/Urban Modeling System: Development, Evaluation, and Applications to Urban Environmental Problems , 2010 .

[32]  J. Bao,et al.  Sensitivity of Low-Level Winds Simulated by the WRF Model in California's Central Valley to Uncertainties in the Large-Scale Forcing and Soil Initialization , 2008 .