- Space weather
Space weather is the concept of changing environmental conditions in
outer space. It is distinct from the concept of weatherwithin a planetary atmosphere, and deals with phenomena involving ambient plasma, magnetic fields, radiationand other matterin space (generally close to Earth but also in interplanetary, and occasionally interstellar space). "Space weather describes the conditions in space that affect Earth and its technological systems. Our space weather is a consequence of the behavior of the sun, the nature of Earth's magnetic field, and our location in the solar system." [ [http://www7.nationalacademies.org/ssb/SSB_Space_weather97.pdf Space Weather: A Research Perspective] , National Academy of Science, 1997 ]
Within our own
solar system, space weather is greatly influenced by the speed and density of the solar windand the interplanetary magnetic field(IMF) carried by the solar wind plasma. A variety of physical phenomena are associated with space weather, including geomagnetic storms and substorms, energization of the Van Allen radiation belts, ionospheric disturbances and scintillation, aurora and geomagnetically induced currents at Earth's surface. Coronal Mass Ejections and their associated shock waves are also important drivers of space weather as they can compress the magnetosphereand trigger geomagnetic storms. Solar Energetic Particles, accelerated by coronal mass ejections or solar flares, are also an important driver of space weather as they can damage electronics onboard spacecraft and threaten the life of astronauts.
Space weather exerts a profound influence in several areas related to space exploration and development. Changing geomagnetic conditions can induce changes in atmospheric density causing the rapid degradation of spacecraft altitude in
Low Earth orbit. Geomagnetic storms due to increased solar activity can potentially blind sensors aboard spacecraft, or interfere with on-board electronics. An understanding of space environmental conditions is also important in designing shielding and life support systems for manned spacecraft. There is also some concern that geomagnetic storms may also expose conventional aircraft flying at high latitudes to increased amounts of radiation. [cite conference | last = Mertens | first = Christopher | title = Progress on NASA NAIRAS Model Development | publisher = Space Policy Institute Workshop on Space Weather, Aviation, and Spaceflight | date = 2008-01-11 | url = http://www.gwu.edu/~spi/Chris_Mertens-NASA.pdf | format = PDF | accessdate = 2008-04-27]
Satellites observing space weather
1995, the joint NASA- European Space Agency Solar and Heliospheric Observatory(SOHO) spacecraft is the main source of near-real time solar data for space weather prediction. It was joined in 1998 by the NASA Advanced Composition Explorer (ACE), which carries a space weather beacon for continuous transmission of relevant in situ space environment data. SOHO and ACE are located near the L1 Lagrangian point, 1% of the earth-sun distance upstream of the earth where it measures solar wind plasma and magnetic field approximately one hour before it reaches the earth. Most recently, the launch of the NASA-ESA Solar-Terrestrial Relations Observatory ( STEREO) added an additional space weather data stream that covers the region between the sun and the earth with stereoscopic imagery. The two STEREO spacecraft drift away from the earth by about 22deg per year, one leading and the other trailing the earth in its orbit.
Major modelling efforts to simulate the space environment from the Sun to the Earth and beyond using three-dimensional global
Magnetohydrodynamics frameworks have been undertaken since the 1990s. In the United States, the two major centers are the [http://csem.engin.umich.edu Center for Space Environment Modeling] (CSEM) and the [http://www.bu.edu/cism/ Center for Integrated Space weather Modeling] (CISM).
Examples of space weather events
1859 Sept 2, disruption of telegraph service.
*The best-known example of space weather events is the collapse of the
HydroQuebecpower network on March 13, 1989due to geomagnetically induced currents. This was started by a transformerfailure, which led to a general blackout, which lasted more than 9 hours and affected 6 million people. The geomagnetic stormcausing this event was itself the result of a Coronal Mass Ejection, ejected from the Sunon March 9, 1989. [ [http://www.agu.org/sci_soc/eiskappenman.html Geomagnetic Storms Can Threaten Electric Power Grid] "Earth in Space", Vol. 9, No. 7, March 1997, pp.9-11 (American Geophysical Union) ]
geomagnetic stormon January 20, 1994temporarily knocked out two Canadian communications satellites, Aniks E1 and E2.
Coronal Mass Ejectionon January 7, 1997hit the Earth's magnetosphereon January 10and caused the loss of the AT&T Telstar 401communication satellite (a $200 million value). [ [http://www.solarstorms.org/SWChapter2.html Space Weather and Satellite loss] ]
*Transpolar routes flown by airplanes are particularly sensitive to space weather, in part because of
Federal Aviation Regulationsrequiring reliable communication over the entire flight. It is estimated to cost about $100,000 each time such a flight is diverted from a polar route. Nine airlines are currently operating polar routes. [ [http://www.aiaa.org/pdf/public/stills_united.pdf United polar flights] Mike Stills]
Solar Energetic Particlesevent happened during a manned mission. However, such a large event happened on August 7, 1972, between the Apollo 16and Apollo 17lunar missions. The dose of particles which would have hit an astronaut outside of earth's protective magnetic field, had this event happened during one of these missions, would have been deadly or at least life-threatening. [ [http://science.nasa.gov/headlines/y2006/01sep_sentinels.htm 1972 Apollo Mission and SEP events (NASA)] ] NozomiMars Probe was hit by a large Solar Energetic Particlesevent on April 21, 2002, which caused large-scale failure. The mission, which was already about 3 years behind schedule, was eventually abandoned in December 2003. [ [http://www.spaceref.com/news/viewnews.html?id=454 Nozomi Mars Probe hit by a large SEP event] ]
pace weather at the Earth’s surface
The best known ground-level consequence of space weather is
geomagnetically induced currents, or GIC. These are damaging electrical currents that can flow in power grids, pipelines and other conducting networks. Rapid magnetic changes on the ground - that occur during geomagnetic storms and are associated with space weather - can also be important for activities such as geophysical mappingand hydrocarbon production.
Air and ship borne magnetic surveys can be affected by rapid magnetic field variations during geomagnetic storms. Storms can cause data interpretation problems where the magnetic field changes due to space weather are of similar magnitude to those of the sub-surface crustal magnetic field in the survey area. Accurate geomagnetic storm warnings, including an assessment of the magnitude and duration of the storm, allows for an economic use of survey equipment.
Geophysics and Hydrocarbon Production
For economic and other reasons, oil and gas production often involves the
directional drillingof well paths many kilometres from a single wellhead in both the horizontal and vertical directions. The accuracy requirements are strict, due to target size – reservoirs may only be a few tens to hundreds of metres across – and for safety reasons, because of the proximity of other boreholes. Surveying by the most accurate gyroscopic method is expensive, since it can involve the cessation of drilling for a number of hours. An alternative is to use a magnetic survey, which enables measurement while drilling (MWD). Near real time magnetic data can be used to correct the drilling direction and nearby magnetic observatories prove vital (Clark and Clarke, 2001; Reay et al, 2006). Magnetic data and storm forecasts can also be helpful in clarifying unknown sources of drilling error on an on-going basis.
* Clark, T. D. G. and E. Clarke, 2001. Space weather services for the offshore drilling industry. In Space Weather Workshop: Looking Towards a Future European Space Weather Programme. ESTEC, ESA WPP-194.
*Carlowicz, M. J., and R. E. Lopez, 2002, "Storms from the Sun", Joseph Henry Press, Washington DC.
* Reay, S. J., W. Allen, O. Baillie, J. Bowe, E. Clarke, V. Lesur, S. Macmillan, 2005. Space weather mom on drilling accuracy in the North Sea. Annales Geophysicae, Vol. 23, pp 3081-3088.
* Odenwald, S. 2006, "The 23rd Cycle;Learning to live with a stormy star", Columbia University Press, (http://www.astronomycafe.net/weather.html)
* [http://www.geomag.bgs.ac.uk/services.html British Geological Survey's Geomagnetism Applications and Services site]
* [http://aurora.fmi.fi/gic_service/english/about_ground_effects.html Finnish Meteorological Institute's ground effects site]
* [http://www.ips.gov.au/Educational/3/1/2 Australian Space Weather Agency's site about effects on aeromagnetic surveys]
Sudden ionospheric disturbance
Coronal Mass Ejection
* Rainer Schwenn, "Space Weather", [http://solarphysics.livingreviews.org/ Living Reviews in Solar Physics] 3, (2006), 2, [http://www.livingreviews.org/lrsp-2006-2 online article] .
* Jean Lilensten and Jean Bornarel, "Space Weather, Environment and Societies", Springer, ISBN 9781402043314.
* [http://www.swpc.noaa.gov/SWN/ NOAA-SWPC Space Weather Now] - (U.S.
National Oceanic and Atmospheric Administration[NOAA] )
* [http://www.ofcm.noaa.gov/nswp-sp/text/a-cover.htm NSWP Strategic Plan] - (NOAA)
* [http://www.ofcm.noaa.gov/nswp-ip/pdf/nswpip.pdf NSWP Implementation Plan] - (NOAA)
* [http://geomag.usgs.gov/ USGS Geomagnetism Program] - (
United States Geological Survey)
* [http://www.lund.irf.se Lund Space Weather Center] - (
Swedish Institute of Space Physics)
* [http://esa-spaceweather.net/ ESA's Space Weather Site] and [http://www.esa-spaceweather.net/swenet/ Space Weather European Network] - (ESA)
* [http://www.solarstorms.org The Human Impacts of Space Weather] - A complete guide to all known impacts of space weather to technology, human health, and an extensive newspaper archive of reported impacts since 1840
* [http://www.spaceweather.com/ Spaceweather.com] - Space Weather news, forecasts and pictures
* [http://www.stormsfromthesun.net Storms from the Sun] - popular science writing about the Sun and space weather effects
* [http://prop.hfradio.org/ Space Weather and Radio Propagation] Live and historical data and images with a perspective on how it affects
* [http://hfradio.org/forums/ Space Weather forums at HFradio.org]
* [http://www.spacew.com/ Solar Terrestrial Dispatch]
* [http://beauty.nascom.nasa.gov/arm/latest/ Active Region Monitor] Live and archived solar region images and data.
* [http://www.ips.gov.au/Space_Weather The Australian Space Weather Agency]
* [http://www.lmsal.com/solarsoft/last_events/ Latest Solar Events] (Large bandwidth)
* [http://www.spaceweather.gc.ca/index_e.php Space Weather Canada]
* [http://sidc.oma.be/index.php3 Official Keepers of the Sunspot Record] Royal Observatory of Belgium / SIDC.
* [http://sohowww.nascom.nasa.gov/ Official SOHO Web site] Solar and Heliospheric Observatory] Solar and space weather images and data.
* [http://www.raben.com/maps/ Solar Region Maps]
* [http://lasco-www.nrl.navy.mil/ Large Angle and Spectrometric Coronagraph Experiment (LASCO)] LASCO solar images and information.
* [http://www.spaceweather.eu/ European Space Weather Portal]
* [http://www.spaceweatherlive.com/index.php?lang=EN SpaceWeatherLive.com] - Realtime auroral activity and solar activity website
* [http://www.spaceweathercenter.org/ Space Weather Center] - Education site with information and interactives.
* [http://www.n0hr.com/ HF Radio Propagation Software for Firefox - Propfire] Firefox plug for monitoring radio propagation, website utility to display HF radio propagation status and article on understanding HF radio propagation forecasting
* [http://www.geomag.bgs.ac.uk/spweather.html British Geological Survey's Space Weather site]
* [http://www.lund.irf.se/ Lund (Sweden) Space Weather Center]
* [http://www.ises-spaceweather.org/ International Space Environment Service]
* [http://www.sec.noaa.gov/ US National Space Environment Center]
* [http://science.nasa.gov/headlines/y2008/06may_carringtonflare.htm? NASA - Carrington Super Flare]
NASA May 6 2008
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