Amirkabir University of Technology Amirkabir Journal of Mechanical Engineering 2008-6032 53 7 2021 09 23 Diagnostical and observational analysis of clear air turbulence over the middle east and Iran Diagnostical and observational analysis of clear air turbulence over the middle east and Iran 4203 4220 4268 10.22060/mej.2021.18770.6886 FA Reza JavanNezhad Graduate Center, Shahid Sattari Aeronautical University, Tehran, Iran. Mahmoud Safar Space Physics Department, Institute of Geophysics, University of Tehran Sarmad Ghader Institute of Geophysics, University of Tehran 0000-0001-9666-5493 Journal Article 2020 07 25 Turbulence forecasting started in World War II when scientists and individuals in the field of aviation began attempting to correlate observed clear air turbulence events with large scale synoptic features. Encounters with significant turbulence or simply bumpiness in flight, are a major concern not only for passenger comfort but also for safe, efficient, and cost-effective aircraft operations. Clear air turbulence represents disorganized fluid motions in the form of micro scale eddies that can take place within cloud-free or limited cloud patches in the free atmosphere, which causes in-flight bumpiness of aircraft. This study aims to present two case studies and comparison of the report of clear air turbulence over center, east and south east crossings over Iran region. Regional weather predictions are carried out using an ensemble forecasting system. In addition, the initial and lateral boundary conditions are taken from the global forecast system. For each member of the ensemble system, two nested computational domains with spatial resolutions of 27000 meters and 9000 meters are used. Case study of the predicted clear air turbulence indicates the proper performance of the predicted meteorological parameters. Turbulence forecasting started in World War II when scientists and individuals in the field of aviation began attempting to correlate observed clear air turbulence events with large scale synoptic features. Encounters with significant turbulence or simply bumpiness in flight, are a major concern not only for passenger comfort but also for safe, efficient, and cost-effective aircraft operations. Clear air turbulence represents disorganized fluid motions in the form of micro scale eddies that can take place within cloud-free or limited cloud patches in the free atmosphere, which causes in-flight bumpiness of aircraft. This study aims to present two case studies and comparison of the report of clear air turbulence over center, east and south east crossings over Iran region. Regional weather predictions are carried out using an ensemble forecasting system. In addition, the initial and lateral boundary conditions are taken from the global forecast system. For each member of the ensemble system, two nested computational domains with spatial resolutions of 27000 meters and 9000 meters are used. Case study of the predicted clear air turbulence indicates the proper performance of the predicted meteorological parameters. https://mej.aut.ac.ir/article_4268_f0f6cc51dacebe556699ccb45e2d43a8.pdf