More Solar Storms In Earth's Future
UPDATED, January 23, 2012
By WeatherBug's Amanda Kibbe
The frequency of auroras over the last few years has given scientists the green light to announce the start of Solar Cycle 24`s solar maximum period. In May 2009, a panel of experts predicted that solar activity would peak in May 2013 with below average intensity, and a sunspot number of 90.
But what does all of this mean? Why is solar activity increasing, and most importantly, what kind of impacts will it have on the Earth and its climate?
While there`s still a lot to learn, new data, advances in technology, and growth in the space weather field have given scientists the ability to answer some of these questions.
Every 10-11 years or so, the Earth experiences fluctuating levels of solar radiation driven mainly by the solar cycle. So why is solar activity increasing now? Solar Cycle 24 actually began in 2008 during a "solar minimum," or a lull in solar activity. It usually takes a few years to approach the "solar maximum," or an increased level of solar activity. This makes 2011 to 2012 the expected start of a solar maximum period.
The previous cycle was unusually long, lasting approximately 12.5 years. New data suggests that this could be related to the length of the flow of plasma on the Sun`s surface, also referred to as the Sun`s "conveyor belt." This conveyor belt carries plasma across the surface of the Sun the same way that a river carries water across the Earth. Until recently, the length of the solar conveyor belt was longer than in previous cycles. However, experts agree that the belt`s length is becoming shorter. This indicates that the period of Solar Cycle 24 will be shorter, and comparable to cycles 19-22 when the sun`s conveyor belt was also shorter.
A solar cycle is observed by counting the frequency of sunspots, or dark-colored magnetic regions that are visible on the Sun. These sunspots often act as the fueling mechanism for solar flares and coronal mass ejections (CMEs), which is a release of solar wind, plasma, and magnetic fields into space.
IMPACTS ON EARTH
If a CME occurs while the Sun is facing the Earth, this blast of matter can impact our planet. The National Oceanic and Atmospheric Administration (NOAA) created three different scales to describe three different effects a CME or solar flare may have on the Earth. These effects include geomagnetic storms, solar radiation storms, and radio blackouts.
The energized particles that are released when a CME bombards Earth`s upper atmosphere can interfere with communication and navigation systems and spacecraft and satellite operations. In extreme events, these storms can cause radiation poisoning to astronauts and passengers in high-altitude aircraft flying over the common polar transoceanic routes. Geomagnetic storms can induce ground currents that damage transformers in power distribution systems. This is especially problematic because these currents can travel through our interconnected electric grids, causing widespread power outages.
The most notable solar storm occurred in 1859, more commonly known as the Solar Superstorm. This event was the most powerful storm in history, causing telegraph systems in Europe and North America to fail. This blast was so strong, that it only took 18 hours for the energy in this CME to reach Earth, whereas most CMEs take 2 to 4 days to arrive. While an event like the storm in 1859 is rare, scientists believe that it could happen again.
Between radiation poisoning, damage to the electric grid, and its impacts on communication and navigation system, a solar maximum seems devastating to a society that is so reliant on technology. However, there is one phenomenon that occurs during geomagnetic storms that provides a beautiful light show for those lucky enough to witness it. This phenomenon is known as the aurora.
Auroras occur when solar wind particles accelerate along Earth`s magnetic field lines. When these particles collide with nitrogen and oxygen in Earth`s upper atmosphere, they emit a photon of light. These small bursts of light are what make up the aurora. The color of the aurora depends on the type of atom emitting light. Oxygen emits a green or brownish red color, and nitrogen emits a blue or red color.
Auroras occur in the Northern Hemisphere (Aurora Borealis) and the Southern Hemisphere (Aurora Australis) in the polar regions. However, in the 1859 Solar Superstorm, auroras were reported as far south as Hawaii and Cuba.
As the hot Sun launches bursts of energy towards the Earth more frequently, some may begin to question the impact an increase in solar activity has on our climate. Two counter arguments have arisen from this debate. Some believe that it is likely that solar activity has an impact on climate based on the "Maunder Minimum" and the "Little Ice Age". The Maunder Minimum occurred between the years 1645 and 1715, when fewer sunspots lead to decreased solar activity. During this period, temperatures were much cooler than average, thus contributing to the "Little Ice Age". This led to the conclusion that the decrease in solar activity lead to cooler than average temperatures on Earth.
Skeptics of this belief are quick to point out current global temperatures. Until recently, we`ve been in a solar minimum, yet temperatures have been warmer than average. This suggests that there is no correlation between solar activity and global temperatures.
The consensus on this issue is that solar variations don`t play a large part in present-day climate change. Instead, scientists believe that greenhouse gases are believed to be the main contributor of global warming today.
The severity of the impacts that the Sun can have on our planet are often overlooked. Experts warn that the next massive solar storm, or what scientists are now calling a "Solar Katrina," could affect millions of people. This would leave many without power, bringing our electricity dependent lifestyle to a screeching halt. Space weather forecasting is still in its early stages, and while the timing of the next major solar event is still unknown, the rise in solar activity will keep space weather in the news for years to come.
Image credit: NASA
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