The Northern Lights (Part Two)
In my recent column about The Northern Lights, the Magnetic Field and Life, I explored the science and the beauty of our planet’s aurora borealis, one of the great natural phenomenon we are most fortunate to see in the far North (and much less frequently in the not-quite-so-far North.)
I learned the hard way that an IPhone camera was really not up to the job; indeed, the battery froze soon after leaving my pocket in the 10 degrees F cold. So the column had few images from where I actually was — about a half hour outside of the Arctic Circle town of Alta.
But here now are some images taken by a generous visitor to the same faraway lodge, who was present the same time as myself.
Her name is Lisa Braithwaite and she is an avid amateur photographer and marketing manager for two popular sites in the English Lake District. This was her first hunting trip for the Northern Lights, and she got lucky. Even in the far northern Norway winter the lights come and go unpredictably — though you can increase your chances if you show up during a time when the sun is actively sending out solar flares.
She came with a Panasonic Lumix DMC-G5 camera and did a lot of research beforehand to increase her chances of capturing the drama should the lights appear. Her ISOs ranged from 1,600 to 64,000, and her shutter speed from 5 to 15 seconds. The aperture setting was 3.5.
In addition to showing some of her work, further on I describe a new NASA-led and international program, based in Norway, to study the still incompletely understood dynamics of what happens when very high energy particles from solar flares meet Earth’s atmosphere.
Partnering with the Japanese Aerospace Exploration Agency (JAXA,) the University of Oslo an other American universities, the two year project will send eleven rockets filled with instruments into the ionosphere to study phenomenon such as the auroral winds and the turbulence that can cause so much trouble to communications networks.
But first, here are some more of Braithwaite’s images, most taken over a one hour period on a single night.
Vast curtains of light are a common feature, often on the horizon but on good nights high up into the sky. The lights can sometimes shimmer and dance, and can feature what appear to be vast spotlights.
While the grandeur of the lights attracts an ever increasing number of adventurous lovers of natural beauty, NASA is also busy in Norway studying the forces that cause the Aurora Borealis — both for the pure science and to better understand the “space weather” that can effect astronauts in low Earth orbit as well as GPS and other communication signals.
The agency has partnered with Norwegian and Japanese colleagues, and other American scientists, in an effort to generally better understand the Earth’s polar cusp — where the planet’s magnetic field lines bend down into the atmosphere and allow particles from space to intermingle with those of Earthly origin.
Solar flares consist of electrically charged particles. They are attracted by the concentrated magnetic fields in the ionosphere around the Earth’s polar regions. This is the reason why the glorious light shows can be observed pretty much exclusively in the far north or the far south.
The two-year project will send eight rockets into space from Norway as part of collaboration of scientists known as The Grand Challenge Initiative – Cusp.
The first mission, the Auroral Zone Upwelling Rocket Experiment or AZURE, is scheduled to launch this month. The rocket will take off from Norway’s Andøya Space Center, on an island off the far northwest coast of Norway, about 100 miles southwest of where I was near the town of Alta.
As a NASA release of March 1 described it, AZURE’s instruments will measure the atmospheric density and temperature of the polar atmosphere, and will deploy visible tracers — trimethyl aluminum (TMA) and a barium/strontium mixture, which ionize when exposed to sunlight.
“These mixtures create colorful clouds that allow researchers to track the flow of neutral and charged particles, respectively,” the release reads. “The tracers will be released at altitudes 71 to 155 miles high and pose no hazard to residents in the region.
“By tracking the movement of these colorful clouds via ground-based photography and triangulating their moment-by-moment position in three dimensions, AZURE will provide valuable data on the vertical and horizontal flow of particles in two key regions of the ionosphere over a range of different altitudes.
“Such measurements are critical if we are to truly understand the effects of the mysterious yet beautiful aurora. The results will be key to a better understanding of the effects of auroral forcing on the atmosphere, including how and where the auroral energy is deposited.”
AZURE will focus specifically on measuring the vertical winds in these polar regions, which create a tumultuous particle soup that re-distributes the energy, momentum and chemical constituents of the atmosphere.
AZURE will study the ionosphere, the electrically charged layer of the atmosphere that acts as Earth’s interface to space, focusing specifically on the E and F regions. The E region — so-named by early radio pioneers who discovered that the region was electrically charge, and so could reflect radio waves — lies between 56 to 93 miles above Earth’s surface. The F region resides just above it, between 93 to 310 miles altitude.
The E and F regions contain free electrons that have been ejected from their atoms by the energizing input of the Sun’s rays, a process called photoionization. After nightfall, without the energizing input of the Sun to keep them separated, electrons recombine with the positively charged ions they left behind, lowering the regions’ overall electron density. The daily cycle of ionization and recombination makes the E and F regions especially turbulent and complex.
It has been known for a century that solar flares create the fantastic displays of the Northern and Southern lights. More recently, it has also become well known that solar flares cause problems for both satellites and navigation systems.
Despite decades of study, scientists still lack the basic knowledge required for predicting when such problems will occur. Once they understand this, it should be possible to make good space weather forecasts just like we do with our weather forecasts on Earth.
When solar storms rain down on the Earth, they cause turbulence in the ionosphere. This turbulence is one of the major unsolved problems of classical physics and physicists are hoping that the rockets will lead to a far better understanding of the phenomenon.
“Without such an understanding of turbulence it is impossible to make the calculations needed for being able to predict severe space weather events,” said Joran Moen of the University of Oslo, and one of the project leaders. He spoke with the University of Oslo research magazine “Apollon.”
The rockets of The Grand Challenge Initiative – Cusp mission will launch over the next two years from the Andøya and Svalbard rocket ranges in Norway. Nine of the rockets are from NASA, one from JAXA and one building built the at the University of Norway.
One particular “sounding” will be made with the launch of four rockets at once, an unusual and complex procedure.
Those involved say this will be among the most ambitious attempts ever using rockets for research purposes.
“We will try to launch four of the rockets at the same time. This has never been done before. It is a historic venture,” said Moen.
Yoshifumi Saito of JAXA further explained that “the four parallel rockets are important for us. By using them we can obtain much better scientific results than would have been the case if we had just launched one rocket at a time.”
Important and compelling science. And think of how many times the scientists will be able to experience the glories of the Northern Lights show.