You’ve bathed in the murky waters of the Blue Lagoon, you’ve circled the Golden Circle and now you’d like to see the sky come alive with dancing green and red lights. Well, you’re not alone. A recent survey conducted for the Iceland Tourist Board found that 16.1% of tourists who visited the country thought the aurora borealis were the most memorable part of their trip.
With support from the Ministry of Industry and Promote Iceland, the Icelandic Meteorological Office has begun forecasting the appearance and visibility of these northern lights, which will more than likely assist you in your planning.
“There are a lot of particles, protons and electrons, coming at very high speeds from the sun,” says Dr. Þórður Arason, a geophysicist at the Met Office, of the aurora. “The magnetic field of the earth is bombarded by these particles.” The particles, brought to earth by solar storms, interact with oxygen and nitrogen in the atmosphere, and electrons are drawn to the north and south poles. As this happens certain elements are illuminated—oxygen creates a great glow and nitrogen creates blue and purplish-red colours. In addition to measuring cloud cover and darkness (the presences of the moon) the Met Office’s forecasts predict the strength of the storms originating off the face of the sun, also known as space weather.
Yes, space weather
On March 13, 1989, the residents of Quebec, Canada, lost electricity for nine hours when the province’s power grid shut down. A few months later Toronto’s stock market screeched to a halt for three hours when their computer system crashed. In both cases, scientists blamed solar storms.
Due to instances such as these, predicting the frequency and intensity of these storms is done for practical purposes. “Most of this monitoring is not for measuring northern lights or an interest in predicting them,” Þórður says. “It’s because these things can influence power grids, satellites and all kinds of instruments.” The Met Office, which doesn’t have the equipment necessary to create their own space weather predictions, uses reports created by the National Oceanic and Atmospheric Association, a US Federal Agency.
The Met Office uses a scale of zero to nine to rank the intensity of aurora displays based on these predictions, with one being “quiet,” two being “low,” and three being “moderate.” The scale, however, does not accurately describe what goes on in the sky. A note on the Met Office website states that “even grade 2 (low activity) can be beautiful and grade 3 (moderate) can be dazzling.”
Over the course of the monitoring, Þórður notes that there have been northern lights displays on nights with low readings, “but stronger readings would give more colourful, vivid and dancing northern lights.”
The most valuable and most accurate information the Met Office provides is the amount of cloud cover over Iceland. “About thirty percent of the time we have a cloud cover of half cloudy or less,” Þórður says. “Seventy percent of the nights are damaged by the clouds.”
Cloudiness and brightness are the biggest disruptors of any northern lights display. The middle of winter may be the darkest time of the year in Iceland, but according to Þórður, northern light displays actually occur with greater frequency around the spring and fall equinoxes in March and September, respectively.
However, the oddest misconception, as well as the most hotly contested one, is whether or not the northern lights make sounds. “It seems to be quite common that people think they can hear noise from the aurora,” Þórður says. “The aurora are formed a hundred kilometres or higher above ground, and the air is so thin up there that it cannot create sound waves. Sound is not transmitted at that height.” If sound could be transmitted from that level, he added, the electrons would make a faint hissing sound.
Unanimous agreement on the nature of the northern lights evades the scientific community and the actual audibility of the aurora is still up for debate. While most scientists would agree that the aurora are a soundless wonder, Unto Laine, a researcher at Aalto University in Finland, recorded this July a clapping sound in an area of high aurora activity, believed to be caused by the same particles causing the display in the sky.
Most northern lights misconceptions centre on when and where it’s best to see them. While some intuitive knowledge on the subject is accurate (it’s easier to see the aurora away from light pollution) there’s a tendency to mistake coincidence for scientific fact.
“There are a lot of people who kind of ‘know’ intuitively that you need to have cold to see them,” Þórður says. “I have often heard from people that you need to have a certain temperature in order to see the northern lights, which is wrong.” If not for the constant presence of the sun during the summer months, it would be possible to see the lights in July.
As Þórður says “There is always something going on here in Iceland, if you can see through the clouds and it’s dark, just wait.”
The Iceland Met Office’s Northern Lights predictions can be seen at http://en.vedur.is/weather/forecasts/aurora/.