Space weather effects on airline communications in the high latitude regions

有效的空中交通管理取决于飞机与空中交通管制中心之间的可靠通信。然而，北极缺乏地面基础设施来支持通过标准甚高频链路进行通信（在北冰洋上空这样的链路是不可能的），并且由于地球的曲率，通过地球同步卫星进行通信在纬度82度以上是不可能的。因此，对于高纬度飞行，有必要使用高频无线电进行通信。高频无线电依靠电离层的反射来实现绕地球曲线的长距离通信。不幸的是，高纬度电离层受到空间天气干扰的影响，可能会中断通信。这些干扰源于太阳上的事件，如太阳耀斑和日冕物质抛射，它们发射出的粒子被地球磁场引导到两极周围的区域。在这类事件中，高频无线电通信可能严重中断，飞机被迫使用较长的低纬度航线，从而增加飞行时间、燃料消耗和成本。通常，在这些较长的航线上着陆和加油的必要性进一步增加了燃料消耗。本建议所述的工作不能防止空间天气干扰及其对无线电通信的影响，但通过详细了解这些现象并利用这些现象提供空间天气信息服务，可以最大限度地减少对飞行操作的干扰。电离层扰动和无线电通信中断的发生遵循太阳活动的11年周期。在太阳活动的最后一个高峰期间，一些事件造成了跨大西洋航线的中断。近年来，由于我们处于太阳活动周期的低潮阶段，无线电通信中断的频率较低。然而，在接下来的几年里，太阳活动将会增加，这将导致无线电通信问题的增加。越来越多地使用跨极地航线，以及需要处理跨大西洋航线上更大的交通密度，这都意味着在未来保持可靠的高纬度通信将更加重要。

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.