RAMS, MM5, and CAMx simulations of Middle-East ozone transboundary-transport

An USAID MERC project generated air quality climatologies (met and concentration), field observational data during periods of poor regional air quality, RAMS and MM5 meso-met simulations, emission inventories, and CAMX photochemical simulations. Both meso-met models reproduced the observed sea/land breezes and up/down slope flows associated with inland mountain ranges. MM5 domain averaged surface temperatures show a diurnal bias of < 0.5 K. Associated speed biases were < 1.5 m/s, while direction biases were < 45 deg. CAMX-reproduced precursor and secondary pollutant plumes that agreed well with observations. In particular, they showed a max ozone concentration at the surface at Jerusalem that resulted from coastal transportation emissions in Israel. It also showed a previously unknown absolute ozone peak at 300 m AGL over Irbid in northern Jordan. Emissions-impact analysis has shown that power plant emissions from coastal Israeli areas produce the largest contributions to the Irbid ozone maxima, a result different from those of areas such as California, where auto emissions have the largest impacts.