Space weather effects on airline communications in the high latitude regions

Efficient air traffic management depends on reliable communications between aircraft and the air traffic control centres. However there is a lack of ground infrastructure in the Arctic to support communications via the standard VHF links (and over the Arctic Ocean such links are impossible) and communication via geostationary satellites is not possible above about 82 degrees latitude because of the curvature of the Earth. Thus for the high latitude flights it is necessary to use high frequency (HF) radio for communication. HF radio relies on reflections from the ionosphere to achieve long distance communication round the curve of the Earth. Unfortunately the high latitude ionosphere is affected by space weather disturbances that can disrupt communications. These disturbances originate with events on the Sun such as solar flares and coronal mass ejections that send out particles that are guided by the Earth's magnetic field into the regions around the poles. During such events HF radio communication can be severely disrupted and aircraft are forced to use longer low latitude routes with consequent increased flight time, fuel consumption and cost. Often, the necessity to land and refuel for these longer routes further increases the fuel consumption. The work described in this proposal cannot prevent the space weather disturbances and their effects on radio communication, but by developing a detailed understanding of the phenomena and using this to provide space weather information services the disruption to flight operations can be minimised.

The occurrence of ionospheric disturbances and disruption of radio communication follows the 11-year cycle in solar activity. During the last peak in solar activity a number of events caused disruption of trans-Atlantic air routes. Disruptions to radio communications in recent years have been less frequent as we were at the low phase of the solar cycle. However, in the next few years there will be an upswing in solar activity that will produce a consequent increase in radio communications problems. The increased use of trans-polar routes and the requirement to handle greater traffic density on trans-Atlantic routes both mean that maintaining reliable high latitude communications will be even more important in the future.

Main beneficiary - the airline industry

The main beneficiary of the proposed research is airline industry. Commercial polar operations began in 1999 with a small number of proving flights. The rapid increase in the number of commercial airline flights over the northern polar region (328 in 2000, rising to 10025 in 2010) provides a high demand for reliable HF radio communications. Based upon experience during previous periods of high solar activity, United Airlines estimated that their additional operational costs will be as high as $13M per year. Similar increased costs will be incurred by other major airlines operating over polar routes. The avoidance of these high additional costs relies on reliable HF communication predictions. In 2000, NAVCANADA [Rome, 2000; Fisher and Jones, 2007] conducted a feasibility study that identified 33 potential city pairs that could benefit from routing aircraft over the poles. On such routes, flight-time savings of two to three hours and financial savings of £20,000 per flight are typical. During an aviation workshop [Fisher and Jones, 2007], commercial and operational details were given for solar activity impacts upon three specific polar operations for the period 17-24 January 2005 that amounted to $250k in visible costs (fuel and time). Estimates for hidden costs (missed passenger connections, cargo, etc) could be as much as $100k per flight. From a European perspective, flights to the west coast of North America and to Hawaii are affected.

Operational planning for flights on polar routes commences 8-12 hours prior to dispatch, and requires the expected quality and availability of HF radio communications to be known for the duration of the flight. Improved predictions, forecasts and nowcasts of HF propagation conditions are needed to avoid unnecessary delays, re-routes and diversions, and reduce fuel usage, maintenance and operational costs. Such improvements will also lead to greater safety.

Other Beneficiaries:

The Environment: The aviation industry is currently considered to have a significant impact on the environment and global warming. When geomagnetic storms divert flights from the polar routes to non-polar routes, time penalties of 2-3 hours can be incurred with an associated increase of fuel used by as much as 50 tonnes per hour (equivalent to 140 tonnes per hour of extra CO2). In addition, the re-routing may require en-route stops adding 3-4 hours in journey time and significant further increases in fuel usage. Thus in addition to improvements in the HF communications, there will be a significant reduction in environmental pollution resulting from the proposed research.

Maritime: In addition to the airline industry, the results of the project will be of direct benefit to the maritime industry for communications with shipping in the Arctic regions. The likely increase in ship traffic in polar regions, as a result of receding ice fields, will create new requirement for maritime HF communications since geostationary satellites do not cover these areas. The efficiency of maritime transport in polar regions, the assessment of risk levels and provision of risk mitigation measures will depend on the ability to forecast the effects of space weather events on terrestrial position-fixing and communications systems. Passage planning for minimum fuel usage and prediction of voyage duration to ensure timely arrival and availability of port facilities will make demands on forecasting services, which will need to be based on understanding of space weather effects on communication and navigation systems.

General Public: Outreach to the wider public is an essential part of this research project, particularly communicating to school children the importance of science whilst keeping them enthused.