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 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.
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.