Space Weather

Space weather includes any and all conditions and events on the sun, in the solar wind, in near-Earth space and in our upper atmosphere that can affect space-borne and ground-based technological systems and through these, human life and endeavor.

Space weather includes any and all conditions and events on the sun, in the solar wind, in near-Earth space and in our upper atmosphere that can affect space-borne and ground-based technological systems and through these, human life and endeavor.

The term “space weather” was coined not long ago to describe the dynamic conditions in the Earth’s outer space environment, in the same way that “weather” and “climate” refer to conditions in Earth’s lower atmosphere. On Earth and in our local space around the Earth this space weather can produce beautiful (northern lights) and destructive results (power and communication blackouts).

Here we will a brief overview of the type of phenomena that make up space weather, the effects we can experience on and near the Earth and some of the industries directly affected by it. Heliophysics is the science of space weather.

The sun goes through a natural cycle approximately every 11 years, hitting peaks and valleys of solar activity.

The cycle is marked by the increase and decrease of sunspots—visible as dark blemishes on the sun’s surface and connected to eruptions such as solar flares and coronal mass ejections. The largest number of sunspots in any given solar cycle is designated as “solar maximum,” and this next peak of activity is predicted to occur in 2013.

The eruptions that occur during solar maximum can’t harm humans on Earth. But scientists observe this activity, what they call space weather, because it can affect satellites in orbit and disrupt power grids on the ground. Watch the movie to see the kind of gigantic, and often beautiful, eruptions we expect to see more of in 2013.

CREDIT: NASA’s Goddard Space Flight Center

The sun was calm in fall 2010 (left), but had cycled toward solar maximum and a more active and varied solar atmosphere by fall 2012 (right).
The sun was calm in fall 2010 (left), but had cycled toward solar maximum and a more active and varied solar atmosphere by fall 2012 (right).

Space Weather Facts

  • Solar flares can sometimes heat the solar surface to temperatures of 80 million F – far hotter that the sun’s core!
  • The fastest Earth-directed coronal mass ejection was recorded on August 4, 1972 and traveled from the sun to earth in 14.6 hours – a speed of nearly 10 million kilometers per hour!
  • On April 8, 1947, the largest sunspot in modern history reached its maximum size of over 330 times Earth’s area.
  • The most powerful solar flare in the last 500 years occurred on September 2, 1859 and was sighted by two astronomers who happened to be looking at the sun at exactly the right time!
  • Between May 10-12, 1999, the solar wind nearly vanished, causing Earth’s magnetosphere to expand in volume by over 100 times!
  • A typical CME can be millions of kilometers in size, but have the mass of only a small mountain!
  • Some sunspots are cool enough that water vapor can form at a temperature of 1,550 C.
  • The most powerful aurora can generate over 1 trillion watts of power.
  • The March 13, 1989 Quebec blackout, the result of a major geomagnetic storm, caused a $6 billion loss to the Canadian economy.
  • During intense solar flares, astronauts see bright flashing streaks of light as a result of high-energy particles zipping through their eyeballs.
  • The largest, single, challenge for astronauts traveling to Mars will be to overcome exposure to solar storms and radiation.
  • Space Weather Forecasting costs only $5 million a year, but supports over $500 billion in annual revenue from the satellite and electrical power industries.
  • Over $2 billion in satellite technology was damaged or destroyed during the last sunspot cycle.
  • A major solar ‘superstorm’ such as the one in 1859 could cost $30 billion a day to the US electrical power grid, and up to $70 billion to the satellite industry.
  • The August 4, 1972, solar particle storm was so powerful that, by some estimates, a space-suited astronaut would have received a lethal does of radiation.
  • During a single second, the sun converts 4 million tons of matter into pure energy.
  • The core of the sun is nearly as dense as lead, and has a temperature of 15 million C.
  • During a severe solar storm, Earth loses about 100 tons of its atmosphere into space.
  • Toy ‘rare-earth’ magnets can be 5 times stronger than a sunspot magnetic field.
The Sun
CREDIT: NASA
CREDIT: NASA/SOHO
CREDIT: NASA/SOHO
CREDIT: NASA/STEREO
CREDIT: NASA/STEREO
CREDIT: NASA/SDO
CREDIT: NASA/SDO
CREDIT: NASA/SOHO
CREDIT: NASA/SOHO

Historical Solar Storms

The Halloween Storms

The figure below shows an example of a very large solar eruptive event from the famous 2 week series of space weather storms from October-November 2003. These events are referred to as the Halloween Storms.

On the morning of Tuesday October 28, 2003 a large sunspot group, labelled NOAA Active region 10486 (dark patch on the bottom right of the solar disk seen in the image in the upper left), erupted around 11:12 UT with a fast CME (observed first in the lower left SOHO LASCO image) and the second largest solar flare observed from space (seen in the upper right SOHO EIT image). The flare and CME produced a strong high-energy particle event that was observed hitting the SOHO spacecraft 1-2 hours later (creating the “snow” in the lower right LASCO image). This CME triggered powerful magnetic storms that caused problems for the electric grid and in-orbit satellite anomalies and failures. credit: NASA/SOHO

July 23, 2012

Explore how NASA observatories worked together to help scientists track the journey of a massive solar eruption in this video.

On July 23, 2012, a massive cloud of solar material erupted off the sun’s right side, zooming out into space and passing one of NASA’s twin STEREO spacecraft along the way.

Scientists clocked this giant cloud, known as a coronal mass ejection, or CME, as traveling over 1,800 miles per second as it left the sun. This was the fastest CME ever observed by STEREO. Luckily, it was moving in a direction safely away from Earth. The harshest space weather can have strong effects on the magnetic system surrounding our planet, which in turn can affect satellites and interrupt GPS and radio communications.

At its worst, rapidly changing magnetic field lines around Earth can induce electric surges in the power utility grids on the ground. Using observations from multiple NASA spacecraft, scientists reconstructed the full shape and expansion of the CME in a computer model. They learned that an earlier, smaller CME helped clear the path for the larger event, thus contributing to its unusual speed.

August 2012

Two wavelengths were blended in one image to create this SDO view of a large solar eruption in Aug. 2012.
Two wavelengths were blended in one image to create this SDO view of a large solar eruption in Aug. 2012.

July 20, 2013

July 20, 2013
July 20, 2013 - Sunny with a chance of wild space weather.

Sources of Space Weather

Solar Flares

A solar flare is a bright flash of X-rays seen during an energetic explosion in an active region of the sun. It’s usually seen as a large burst of X-rays, but may also have a coincident bright flash of white light. A flare lasts a matter of minutes but releases an immense amount of energy. During solar flares the sun can be 1,000 times brighter in X-rays than usual.

Solar Flare
Solar activity releases streams of energetic particles that, if directed toward Earth, can increase atmospheric radiation levels for hours or days. CREDIT: NASA's Goddard Space Flight Center

Coronal Mass Ejections

A Coronal Mass Ejection (CME) occurs when a prominence suspended above the surface of the sun erupts and sends millions of tons of material into space. This cloud of charged particles is generally confined within a magnetic field (like a magnetic bubble), expanding and traveling out through the solar system at speeds from about 200 km/s up to a staggering 2,000 km/s. When directed toward Earth, a CME typically arrives 2-3 days after eruption but in exceptional cases can arrive in less than 24 hours.

Geomagnetic Storms

Earth’s magnetosphere is a bubble created around us by our magnetic field, which protects us from most of the particles the sun throws at us. When a CME or high-speed stream arrives at Earth, it buffets the magnetosphere. High pressure discontinuities or and interplanetary shock waves can penetrate deeply and strongly affect the deep interior of Earth’s magnetosphere. There are also other modes of interaction. For example, if the arriving solar magnetic field is directed southward, it interacts strongly with Earth’s oppositely oriented magnetic field. As a result, Earth’s magnetic field is peeled open like an onion, allowing energetic solar wind particles to stream down the field lines to hit the atmosphere over the poles. At Earth’s surface, a magnetic storm is seen as a rapid drop in Earth’s magnetic field strength (typically a drop of 30 to 500 nT in 1-2 hours). This decrease lasts about 6 to 12 hours, after which the magnetic field gradually recovers over a period of several days.

Corotating Interaction Regions (CIR)

The solar wind can be highly structured because of structure within the sun’s upper atmosphere that generates and releases the solar wind. Such structures can be in the form of continuous and interacting streams that sweep periodically across Earth’s orbit. The variations in the solar wind parameters within these streams can cause geomagnetic disturbances within Earth’s space environment.

CREDIT: NASA, Radiation Belt Storm Probes Launch Press Kit

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