Solar Effects

Space Weather Operations

SEC's Space Weather Operations branch (SWO) is the national and world warning center for disturbances that can affect people and equipment working in the space environment. Jointly operated by NOAA and the U.S. Air Force, SWO provides forecasts and warnings of solar and geomagnetic activity to users in government, industry, and the private sector.

SWO continuously monitors, analyzes, and forecasts the environment between the Sun and Earth. The Center receives solar and geophysical data in real time from a large number of ground-based observatories and satellite sensors around the world. SWO forecasters use these data to predict solar and geomagnetic activity and issue worldwide alerts of extreme events.

Solar Cycles

The Sun goes through cycles of high and low activity that repeat approximately every 11 years. The number of dark spots on the Sun (sunspots) marks this variation; as the number of sunspots increases, so does solar activity. Sunspots are sources of flares, the most violent events in the solar system. In a matter of minutes, a large flare releases a million times more energy than the largest earthquake.

Solar-Terrestrial Effects

Episodic solar activity has a number of effects that are of interest to us. A radiation dose from energetic particles is an occasional hazard for astronauts and for electronics on satellites. Geomagnetic field disturbances may damage power systems, disrupt communications, degrade high-tech navigation systems, or create the spectacular aurora (Northern and Southern lights). SEC provides warnings of these events and continues the solar monitoring that began 400 years ago with Galileo's invention of the telescope.

Earth-Space Activities
... disrupted by solar and geomagnetic events

• Satellite operations
• Navigation
• Space Shuttle and Space Station activities
• High-altitude polar flights
• Electric power distribution
• Long-line telephone communication
• HF radio communication
• Pipeline operations
• Geophysical exploration

Scientific Areas
... studied to understand the Space Environment:

• The Sun
• The interplanetary medium
• The geomagnetic field
• Earth's ionosphere and upper atmosphere

 

Earth-Space Activities Disrupted by Solar Events

	Solar-Geophysical Phenomena monitored by SEC
	Solar Phenomena	Solar Radiation Hazards	Geomagnetic Activity	Solar Radio Interference
Satellite operations
Monitoring orbital variation			X
Monitoring command & control anomalies		X	X	X
Ground-to-spacecraft communications			X	X
Aviation:
Middle-latitude communication (VHF)				X
Polar-cap communication (HF)		X	X
Navigation (VLF)		X	X
High-altitude polar flights			X
Electric Power Distribution			X
Long-line telephone communications			X
HF communication			X
Pipeline operations			X
Geophysical exploration			X
Scientific satellite studies - Shuttle, Spacelab, solar physics, solar constant measurement, ozone variation, interplanetary missions	X		X
Scientific rocket studies - Sun, magnetosphere, ionosphere, upper atmosphere	X		X
Scientific ground studies - Sun, interplanetary medium, magnetosphere, troposphere; geomagnetic, seismological, biological	X		X

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