![]() ![]() This approach will (1) illustrate the real-world impact of the phenomena, (2) illuminate the potential utility of a relatively new kind of sensor and measurement technique for providing the characterization in three dimensions of the ionospheric structure, and (3) indicate the limitations of current climatology-driven planning tools. We focus on the potential impact of ionospheric disturbances, in particular ionospheric “bubbles” on RF propagation. This paper discusses the space weather environment and its characteristics and how these conditions impact radio frequency propagation: the approach is general, but the application is specific to a particular event. The events of 4 March 2002 motivated us to develop the Mesoscale Ionospheric Simulation Testbed model, which can be used to improve warnings of potential UHF outages during future military operations. A forensics study of Takur Ghar with data from the Global Ultraviolet Imager on the NASA Thermosphere Ionosphere Mesosphere Energetics and Dynamics mission showed the presence of ionospheric bubbles (regions of depleted electron density) along the line of sight between the Chinook and the UHF communications satellites in geostationary orbit that could have impacted communications. However, it is also possible that ionospheric anomalies together with multipath effects could have combined to decrease the signal-to-noise ratio of the communication links used by the QRF. During a subsequent analysis of Operation Anaconda, these outages were attributed to poor performance of the UHF radios on the helicopters and to blockage by terrain. In this paper, we consider UHF SATCOM outages that occurred during repeated attempts to notify a Quick Reaction Force (QRF) on board an MH-47H Chinook to avoid a “hot” landing zone at the top of Takur Ghar. During Operation Anaconda, the Battle of Takur Ghar occurred at the summit of a 3191 m Afghan mountaintop on 4 March 2002 when the ionosphere was disturbed and could have affected UHF Satellite Communications (SATCOM). Early military operations occurred during the peak of solar cycle 23 when ionospheric variability was enhanced. ![]() Here we consider a communications outage during Operation Anaconda in Afghanistan that may have been related to ionospheric disturbances. Space weather impacts on communications are often presented as a raison d' etre for studying space weather (e.g., Solar and Space Physics: A Science for a Technological Society, 2013). ![]()
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