The United Arab Emirates is a new country that has had little time to accumulate a scientific heritage. Meteorologically researched and documented weather material for forecasters is virtually non-existent and that available is fragmented and anecdotal. The thesis tackles this problem by identifying weather phenomena significant to aviation in the Emirates and particularly at Abu Dhabi International Airport (ADIA). Mechanisms responsible for their development are described and applicable forecasting rules and principles are derived. Surface and upper air observation data at ADIA from 1983 to 2002 were analysed to identify the weather phenomena, their associated weather systems and for statistical analyses. When relevant, observation data at Al Ain was also used. Post-processed numerical weather prediction Global Forecast Service Eta model data are used and when and where possible radar and satellite imagery. A secondary aim is to provide information of the general seasonal climate. This was achieved by means of a literature study of the dominating weather systems and the presentation of surface and upper air mean circulation charts. Fog is the most important weather phenomenon and serious disrupter of aviation at ADIA throughout the year. It does not occur during Shamal conditions, but fog can form well inland on the edge of the Empty Quarter at the Liwa Oasis when the Shamal wind becomes light. Contrary to local belief, fog is unlikely to occur on two, or more, consecutive nights. The Shamal can last for several days and disrupt helicopter flights to the oil rigs, while anabatic and katabatic effects often make it gustier and stronger inland at Al Ain than ADIA. While dust storms occur in strong southerly winds off the desert, the Shamal can bring dust from further afield from the north as can the previously unreported Nashi wind. The sea breeze can extend about 150 km inland to Al Ain and the Liwa Oasis. Thunderstorms associated with winter upper air troughs from the west, are the main producers of rain, while occasional thunderstorms off the Hajar Mountains in the east bring some rain in summer. Tropical depressions are a rare event. / Thesis (PhD)--University of Pretoria, 2010. / Geography, Geoinformatics and Meteorology / PhD / Unrestricted

Approved for public release; distribution in unlimited. / On day five of combat operations during Operation IRAQI FREEDOM, advances by coalition forces were nearly halted by a dust storm, initiated by the passage of a synoptically driven cold front. This storm impacted ground and air operations across the entire Area of Responsibility, and delayed an impending ground attack on the Iraqi capital. Military meteorologists were able to assist military planners in mitigating at least some of the effects of this storm. This thesis examines the synoptic conditions leading to the severe dust storm, evaluates the numerical weather prediction model performance in predicting the event, and reviews metrics pertaining to the overall impacts on the Operation IRAQI FREEDOM combined air campaign. In general, the numerical model guidance correctly predicted the location and onset of the dust storms on 25 March, 2003. As a result of this forecast guidance, mission planners were able to front load Air Tasking Orders with extra sorties prior to the onset of the dust storm, and were able to make changes to planned weapons loads, favoring GPS-guided munitions. / Captain, United States Air Force