Saturday, February 19, 2011: 1:00 PM
145B (Washington Convention Center )
The direct electromagnetic impacts of solar eruptions on our high tech installations are sufficiently investigated, but in our modern world there are some indirect impacts that are far more worrying. It is since the 1980ies that we have electronically controlled infrastructures, but only in the 21st century the interdependencies grew to an extreme by a really global interconnectivity and the widespread use of satellite communications. Many of our network technologies are robust at first glance, but the closer we look, the more open questions we find. A typical example, is digital communications standard GSM that most our cell phones are working on. Basically it is robust against solar impact by its signal strength and shielding, so neither the radio nor the wire line communications links should be vulnerable. But the GSM standard needs an accurate timing to allow for a proper execution of TDMA (time division multiple access) protocols. The respective technical standards only request time accuracy, but do not define how to get there: The use of a GPS-based time source itself can provide the required accuracy and robustness, but its performance is based on the assumption that the GPS signal itself is present. What if this assumption is false as satellites would shut down service under very bad space weather? How long can our telecommunications networks live without time sync and how stable is network time? There is no general answer to this question as it depends on the type of time sources installed in different networks. So basically we can only guess. The European Commission's Joint Research Centre (JRC) has made first steps to assess the problems not from the solar science side but from the perspective of infrastructure vulnerability.
Also in other sectors, there are critical infrastructures that might be affected. Power grids, air traffic control systems and intelligent transport systems need to be looked at. And would our financial trading places have to shut down if the accuracy of the time stamp for an electronic order was not given any more? But GPS time is only one example. Due to the sectors' interdependence, a power outage could from electrically induced currents after a solar eruption could indirectly also impact the communications services and vice versa. It is about time to investigate the vulnerabilities and to introduce provisions for such extraordinary risks. Even if it turns out that the expected solar eruptions high in 2013/2014 will not cause any major damage, the dependence of our modern society on radio technologies like GPS, GSM, WLAN or ultra wideband technologies will increase every year. And the next solar cycle high is just another 11 years away. Time enough to better understand its implications and to harden our infrastructures, but we need to start now.