Solar Cycle 24
Encyclopedia
Solar Cycle 24 is the 24th solar cycle
since 1755, when recording of solar sunspot
activity began. It is the current solar cycle, and began on . The cycle continues to fall below predictions and is currently exhibiting 50% lower sunspot activity than predicted in May 2009.
s. This would make it the least active cycle since solar cycle 6
, which ended in the year 1823.
According to NASA
, the intensity of geomagnetic storm
s during Solar Cycle 24 may be elevated in some areas where the Earth's magnetic field
is weaker than expected. This fact was discovered by the THEMIS
spacecraft in 2008. A 20-fold increase in particle counts that penetrate the Earth's magnetic field may be expected.
While acknowledging that the next solar maximum will not necessarily produce unusual geomagnetic activity, astrophysicist Michio Kaku
has taken advantage of the media focus on the 2012 phenomenon to draw attention to the need to develop strategies for coping with the terrestrial damage that such an event could inflict. He asserts that governments should ensure the integrity of electrical infrastructures, so as to prevent a recurrence of disruption akin to that caused by the solar storm of 1859
.
The current solar cycle is currently the subject of research, as it does not appear to be generating sunspots in the manner which would be expected. Sunspots did not begin to appear immediately after the last minimum (in 2008) and although they started to reappear in late 2009, they are at significantly lower than anticipated.
s emanating from the Earth-facing hemisphere by analyzing images recorded at NASA's Solar Dynamics Observatory
. The observed velocities of the ejecta varied between 670,560 m/s and 1,118,000 m/s (metre per second), and were expected to reach the Earth's geomagnetic field sometime between August 4 and early August 5. As of 05:00 UTC August 4, the estimated time of arrival of the series was as follows:
All four ejections were described as large and, according to scientists, possessed enough energy to cause aurorae
to be observed by naked eye in non-polar regions. According to reports, aurorae would be visible at night toward the poleward horizon in temperate latitudes between 45° to 50°, and near overhead in regions closer to the poles. The initial coronal mass ejection of August 1 originated from a sunspot designated Sunspot 1092, which was large enough to be seen without the aid of a solar telescope
. Aside from the visual effects of this CME series, scientists warned that electric impulses caused by disruptions in the magnetic field due to the ionized particles may damage infrastructure such as power grids and telephone lines not adequately protected against induced magnetic current
. It has also been reported that several Earth-orbiting satellites may be in similar danger. According to Leon Golub, an astronomer at CfA:
and Wisconsin
in the United States
, and Ontario
, Canada
near latitude 45° North (see image at right). European observers reported sightings as far south as Denmark
near latitude 56° North. The aurorae were reportedly green in color due to the interaction of the solar particles with oxygen atoms in the relatively denser atmosphere of southern latitudes. This, however, was only the first wave of solar wind; the third and last was expected for the evening of August 5, but missed Earth entirely.
and Alabama
. The storm was the biggest since October 2003. The storm also created a G4 out of 5 geomagnetic storm, enough to make power outages. In the southern hemisphere, auroras could have been seen as far north as South Africa
, Southern Chile
and Southern Australia
.
Just 22 hours later, NASA says, an X2.1 class solar flare – some four times stronger than the earlier flare – erupted from the same sunspot region. The second flare peaked on September 6 at 6:20 p.m. EDT (22:20 UTC)
A day later, a third (slightly weaker) X1.8-class event on flare erupted from sunspot 1283 on September 7 at 6:38 p.m. EDT.(22:38 UTC).
An Aurora alert was issued for September 8-11. An X class flare can cause a "strong" radio blackout, categorized as R3, has the potential to cause about an hour-long blackout.
Then on September 24, a large X2 flare erupted out of sunspot 1302. The flare was not earth directed. On the next day, a M7 flare was unleashed out of the same sunspot.
.
Solar cycle
The solar cycle, or the solar magnetic activity cycle, is a periodic change in the amount of irradiation from the Sun that is experienced on Earth. It has a period of about 11 years, and is one component of solar variation, the other being aperiodic fluctuations. Solar variation causes changes in...
since 1755, when recording of solar sunspot
Sunspot
Sunspots are temporary phenomena on the photosphere of the Sun that appear visibly as dark spots compared to surrounding regions. They are caused by intense magnetic activity, which inhibits convection by an effect comparable to the eddy current brake, forming areas of reduced surface temperature....
activity began. It is the current solar cycle, and began on . The cycle continues to fall below predictions and is currently exhibiting 50% lower sunspot activity than predicted in May 2009.
Predictions
It is predicted that Solar Cycle 24 will peak in May 2013 with about 58 sunspotSunspot
Sunspots are temporary phenomena on the photosphere of the Sun that appear visibly as dark spots compared to surrounding regions. They are caused by intense magnetic activity, which inhibits convection by an effect comparable to the eddy current brake, forming areas of reduced surface temperature....
s. This would make it the least active cycle since solar cycle 6
Solar cycle 6
Solar cycle 6 is the sixth solar cycle since 1755, when recording of solar sunspot activity began. The solar cycle lasted 12.4 years, beginning in December 1810 and ending in May 1823. The maximum smoothed sunspot number observed during the solar cycle was 48.7, and the minimum was 0.1.-References:...
, which ended in the year 1823.
According to NASA
NASA
The National Aeronautics and Space Administration is the agency of the United States government that is responsible for the nation's civilian space program and for aeronautics and aerospace research...
, the intensity of geomagnetic storm
Geomagnetic storm
A geomagnetic storm is a temporary disturbance of the Earth's magnetosphere caused by a disturbance in the interplanetary medium. A geomagnetic storm is a major component of space weather and provides the input for many other components of space weather...
s during Solar Cycle 24 may be elevated in some areas where the Earth's magnetic field
Earth's magnetic field
Earth's magnetic field is the magnetic field that extends from the Earth's inner core to where it meets the solar wind, a stream of energetic particles emanating from the Sun...
is weaker than expected. This fact was discovered by the THEMIS
Themis
Themis is an ancient Greek Titaness. She is described as "of good counsel", and is the embodiment of divine order, law, and custom. Themis means "divine law" rather than human ordinance, literally "that which is put in place", from the verb τίθημι, títhēmi, "to put"...
spacecraft in 2008. A 20-fold increase in particle counts that penetrate the Earth's magnetic field may be expected.
Speculation
Solar Cycle 24 has been the subject of various hypotheses and commentary pertaining to its potential effects on Earth.While acknowledging that the next solar maximum will not necessarily produce unusual geomagnetic activity, astrophysicist Michio Kaku
Michio Kaku
is an American theoretical physicist, the Henry Semat Professor of Theoretical Physics in the City College of New York of City University of New York, the co-founder of string field theory, and a "communicator" and "popularizer" of science...
has taken advantage of the media focus on the 2012 phenomenon to draw attention to the need to develop strategies for coping with the terrestrial damage that such an event could inflict. He asserts that governments should ensure the integrity of electrical infrastructures, so as to prevent a recurrence of disruption akin to that caused by the solar storm of 1859
Solar storm of 1859
The solar storm of 1859, also known as the Solar Superstorm, or the Carrington Event, which occurred during solar cycle 10, was the most powerful solar storm in recorded history, and the largest flare, observed by Richard Christopher Carrington, became known as the Carrington Super...
.
The current solar cycle is currently the subject of research, as it does not appear to be generating sunspots in the manner which would be expected. Sunspots did not begin to appear immediately after the last minimum (in 2008) and although they started to reappear in late 2009, they are at significantly lower than anticipated.
Coronal mass ejections
On August 1, 2010, scientists at the Harvard-Smithsonian Center for Astrophysics (CfA) observed a series of four large CMECoronal mass ejection
A coronal mass ejection is a massive burst of solar wind, other light isotope plasma, and magnetic fields rising above the solar corona or being released into space....
s emanating from the Earth-facing hemisphere by analyzing images recorded at NASA's Solar Dynamics Observatory
Solar Dynamics Observatory
The Solar Dynamics Observatory is a NASA mission which will observe the Sun for over five years. Launched on February 11, 2010, the observatory is part of the Living With a Star program...
. The observed velocities of the ejecta varied between 670,560 m/s and 1,118,000 m/s (metre per second), and were expected to reach the Earth's geomagnetic field sometime between August 4 and early August 5. As of 05:00 UTC August 4, the estimated time of arrival of the series was as follows:
- Wednesday, August 4 – 07:00 UTCCoordinated Universal TimeCoordinated Universal Time is the primary time standard by which the world regulates clocks and time. It is one of several closely related successors to Greenwich Mean Time. Computer servers, online services and other entities that rely on having a universally accepted time use UTC for that purpose...
- Wednesday, August 4 – 17:00 UTC
- Thursday, August 5 – 00:00 UTC
- Thursday, August 5 – 06:00 UTC
All four ejections were described as large and, according to scientists, possessed enough energy to cause aurorae
Aurora (astronomy)
An aurora is a natural light display in the sky particularly in the high latitude regions, caused by the collision of energetic charged particles with atoms in the high altitude atmosphere...
to be observed by naked eye in non-polar regions. According to reports, aurorae would be visible at night toward the poleward horizon in temperate latitudes between 45° to 50°, and near overhead in regions closer to the poles. The initial coronal mass ejection of August 1 originated from a sunspot designated Sunspot 1092, which was large enough to be seen without the aid of a solar telescope
Solar telescope
A solar telescope is a special purpose telescope used to observe the Sun. Solar telescopes usually detect light with wavelengths in, or not far outside, the visible spectrum.-Professional solar telescopes:...
. Aside from the visual effects of this CME series, scientists warned that electric impulses caused by disruptions in the magnetic field due to the ionized particles may damage infrastructure such as power grids and telephone lines not adequately protected against induced magnetic current
Faraday's law of induction
Faraday's law of induction dates from the 1830s, and is a basic law of electromagnetism relating to the operating principles of transformers, inductors, and many types of electrical motors and generators...
. It has also been reported that several Earth-orbiting satellites may be in similar danger. According to Leon Golub, an astronomer at CfA:
Aurorae observations
In the early morning hours of August 4, 2010 aurorae occurred in the northern hemisphere that were visible at latitudes as far south as MichiganMichigan
Michigan is a U.S. state located in the Great Lakes Region of the United States of America. The name Michigan is the French form of the Ojibwa word mishigamaa, meaning "large water" or "large lake"....
and Wisconsin
Wisconsin
Wisconsin is a U.S. state located in the north-central United States and is part of the Midwest. It is bordered by Minnesota to the west, Iowa to the southwest, Illinois to the south, Lake Michigan to the east, Michigan to the northeast, and Lake Superior to the north. Wisconsin's capital is...
in the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
, and Ontario
Ontario
Ontario is a province of Canada, located in east-central Canada. It is Canada's most populous province and second largest in total area. It is home to the nation's most populous city, Toronto, and the nation's capital, Ottawa....
, Canada
Canada
Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...
near latitude 45° North (see image at right). European observers reported sightings as far south as Denmark
Denmark
Denmark is a Scandinavian country in Northern Europe. The countries of Denmark and Greenland, as well as the Faroe Islands, constitute the Kingdom of Denmark . It is the southernmost of the Nordic countries, southwest of Sweden and south of Norway, and bordered to the south by Germany. Denmark...
near latitude 56° North. The aurorae were reportedly green in color due to the interaction of the solar particles with oxygen atoms in the relatively denser atmosphere of southern latitudes. This, however, was only the first wave of solar wind; the third and last was expected for the evening of August 5, but missed Earth entirely.
February 2011
Sunspot group 1158 produces an X class solar flare, the first of its kind since December 2006.August 2011
In early August, three sunspots unleashed M class flares, with the highest being M9.3. On the night of August 5th, auroras were reported as far south as OklahomaOklahoma
Oklahoma is a state located in the South Central region of the United States of America. With an estimated 3,751,351 residents as of the 2010 census and a land area of 68,667 square miles , Oklahoma is the 28th most populous and 20th-largest state...
and Alabama
Alabama
Alabama is a state located in the southeastern region of the United States. It is bordered by Tennessee to the north, Georgia to the east, Florida and the Gulf of Mexico to the south, and Mississippi to the west. Alabama ranks 30th in total land area and ranks second in the size of its inland...
. The storm was the biggest since October 2003. The storm also created a G4 out of 5 geomagnetic storm, enough to make power outages. In the southern hemisphere, auroras could have been seen as far north as South Africa
South Africa
The Republic of South Africa is a country in southern Africa. Located at the southern tip of Africa, it is divided into nine provinces, with of coastline on the Atlantic and Indian oceans...
, Southern Chile
Chile
Chile ,officially the Republic of Chile , is a country in South America occupying a long, narrow coastal strip between the Andes mountains to the east and the Pacific Ocean to the west. It borders Peru to the north, Bolivia to the northeast, Argentina to the east, and the Drake Passage in the far...
and Southern Australia
Southern Australia
The term southern Australia is generally considered to include the States and territories of Australia of New South Wales, Victoria, South Australia, Tasmania and the Australian Capital Territory...
.
September 2011
Sunspot 1283 erupted with an M5.3 solar flare on September 5, just after 8 p.m. EDT (00 UTC)Just 22 hours later, NASA says, an X2.1 class solar flare – some four times stronger than the earlier flare – erupted from the same sunspot region. The second flare peaked on September 6 at 6:20 p.m. EDT (22:20 UTC)
A day later, a third (slightly weaker) X1.8-class event on flare erupted from sunspot 1283 on September 7 at 6:38 p.m. EDT.(22:38 UTC).
An Aurora alert was issued for September 8-11. An X class flare can cause a "strong" radio blackout, categorized as R3, has the potential to cause about an hour-long blackout.
Then on September 24, a large X2 flare erupted out of sunspot 1302. The flare was not earth directed. On the next day, a M7 flare was unleashed out of the same sunspot.
October 2011
On October 22, 2011, the sun unleashed a M1 flare, this time, was heading towards MarsMars
Mars is the fourth planet from the Sun in the Solar System. The planet is named after the Roman god of war, Mars. It is often described as the "Red Planet", as the iron oxide prevalent on its surface gives it a reddish appearance...
.
See also
- Earth's magnetic fieldEarth's magnetic fieldEarth's magnetic field is the magnetic field that extends from the Earth's inner core to where it meets the solar wind, a stream of energetic particles emanating from the Sun...
- List of solar cycles
- March 1989 geomagnetic stormMarch 1989 geomagnetic stormThe March 1989 geomagnetic storm was a severe geomagnetic storm that caused the collapse of Hydro-Québec's electricity transmission system. It occurred during solar cycle 22.-Geomagnetic storm and auroras:...
- Solar storm of 1859Solar storm of 1859The solar storm of 1859, also known as the Solar Superstorm, or the Carrington Event, which occurred during solar cycle 10, was the most powerful solar storm in recorded history, and the largest flare, observed by Richard Christopher Carrington, became known as the Carrington Super...
- Solar variationSolar variationSolar variation is the change in the amount of radiation emitted by the Sun and in its spectral distribution over years to millennia. These variations have periodic components, the main one being the approximately 11-year solar cycle . The changes also have aperiodic fluctuations...
External links
- Solar Cycle Progression at the National Oceanic and Atmospheric AdministrationNational Oceanic and Atmospheric AdministrationThe National Oceanic and Atmospheric Administration , pronounced , like "noah", is a scientific agency within the United States Department of Commerce focused on the conditions of the oceans and the atmosphere...
- Solar Cycle 24 at the National Oceanic and Atmospheric AdministrationNational Oceanic and Atmospheric AdministrationThe National Oceanic and Atmospheric Administration , pronounced , like "noah", is a scientific agency within the United States Department of Commerce focused on the conditions of the oceans and the atmosphere...
- SolarCycle24.com, a website with live data from Solar Cycle 24