CAMx simulations of Middle-East ozone concentration-trends by use of RAMS and MM5 input

A USAID regional international project has generated observed air quality climatologies (met and concentration), field observational data during periods of poor regional air quality, RAMS and MM5 met-model simulations, emission inventories, and CAMX photochemical simulations. Both meso-met models reproduced the observed sea/land breeze life cycles, which showed interactions between these flows and up/down slope flows associated with inland mountain ranges. MM5 domain averaged 10 m temperatures show a bias of less than 2 K over a diurnal cycle. Associated speed biases were less than 1.5 m/s, while direction biases were less than 45 deg. CAMX reproduced precursor and secondary pollutant plumes at the surface and at 300 m that agree well with observations. In particular, they showed max ozone concentrations at 300 m over Jerusalem that resulted from coastal urban emissions in Israel. It also showed a previously unknown absolute ozone peak over Jordan from the same sources. Emissions-impact analysis has shown that power plant emissions produce the largest contributions to this absolute ozone maxima, a result different from those of areas such as California, where auto emissions have the largest impacts. Additional simulations have projected planned regional emission patterns into projected ozone trends.