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Armin Aulinger, Volker Matthias, and Markus Quante

Deposition Model, version 2, mechanism were converted to the less detailed CB4 mechanism. Although, the reactive species modeled with the CB4 mechanism are not needed for the current B(a)P version of CMAQ, we decided not to simplify the mechanism because all of these reactive species play an important role for the formation of secondary organic aerosols from NMVOCs. Further, they will be needed in our future model versions for which we plan to include chemical degradation of POPs. 4. Boundary and initial

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Jesse O. Bash, Patricia Bresnahan, and David R. Miller

boundary layer resistances, C M ,Hg x is the concentration of mercury species x in the leaf mesophyll, and K LA,Hg x is the partitioning coefficient of mercury species x between the foliar tissue and atmosphere. 4. Future directions Currently there are several key parameters that need further work before the proposed modeling framework can be implemented into an AQM. The role of ligands on vegetative mercury uptake and the natural redox properties in plants need to be investigated at background

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M. Talat Odman, Yongtao Hu, Alper Unal, Armistead G. Russell, and James W. Boylan

visibility days. Every 10 years, progress toward these goals must be demonstrated. The first regional haze state implementation plans (due by December 2007) must demonstrate progress toward natural conditions by evaluating the change in visibility between current conditions (2000–04) and the first progress check point (2014–18). Progress can be measured by comparing the projected visibility on the 20% worst days to a straight line drawn between current visibility (2000–04) and natural conditions (2064

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Ho-Chun Huang, Xin-Zhong Liang, Kenneth E. Kunkel, Michael Caughey, and Allen Williams

titration in metropolitan areas. It could also be the result of inefficient dynamical processes that removed the O 3 precursor gases away from the polluted boundary layer and into the free troposphere, as well as the possibility of weaker NO x deposition simulated by the AQM. It is difficult to examine the magnitude of the emissions with nearly no available observed emissions. As described in the introduction section, the current modeling system was designed for application at climatic time scales and

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John S. Irwin, William B. Petersen, and Steven C. Howard

1. Introduction Implicit in current air quality models, and in the discussion of this paper, is the assumption that the temporal and spatial variations in observed hourly concentration values can be envisioned as being partly deterministic and partly stochastic. For specified boundary conditions, the deterministic part of the concentration variations in time and space are the ensemble-average hourly concentrations to be seen at each location in the modeling domain. What we observe at any given

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Golam Sarwar and Prakash V. Bhave

system currently includes three different gas-phase chemistry solvers—the Sparse-Matrix Vectorized Gear solver, the Rosenbrock solver, and the Euler Backward Iterative solver; the Rosenbrock solver was used for this study. The meteorological driver for the CMAQ modeling system was the fifth-generation Pennsylvania State University–National Center for Atmospheric Research Mesoscale Model (MM5) system, version 3.5 ( Grell et al. 1994 ). Meteorological data obtained from the MM5 system were processed

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George Kallos, Marina Astitha, Petros Katsafados, and Chris Spyrou

) , and Kallos et al. (2006) . There are also indications of the existence of transport patterns on larger scales toward/from the Mediterranean region ( Ramanathan et al. 2001 ; Lelieveld et al. 2002 ; Carmichael et al. 2002 ). The current status of knowledge on the above aspects is discussed in this paper, providing some summary remarks on the paths and scales of transport and transformation of PM in the greater Mediterranean region (GMR). The tools used for such analysis are atmospheric and air

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