The Global Oscillation Network Group (GONG) is a worldwide network of six identical telescopes, designed to have 24/7 observations of the Sun.[1] The network serves multiple purposes, including the provision of operation data for use in space weather prediction,[2] and the study of solar internal structure and dynamics using helioseismology.
Deployed in 1995, GONG is a set of six observing systems geographically distributed around the Earth so that the Sun can be observed as continuously as possible. The six observatories are the Teide Observatory (Canary Islands), the Learmonth Solar Observatory (Western Australia), the Big Bear Solar Observatory (California), the Mauna Loa Observatory (Hawaii), the Udaipur Solar Observatory (India) and the Cerro Tololo Inter-American Observatory (Chile). With these sites, GONG typically can observe the Sun 91% of the time, 24/7.[3] GONG was constructed to provide observations for helioseismology, which aims to understand the solar interior by analyzing the sound waves that are trapped in it. In 2001, the original GONG detectors were upgraded to 1000 x 1000 pixels and continuous magnetograms were implemented, and the new system is known as GONG++. While GONG still provides helioseismology data, it now also provides full-disk solar magnetic field maps (magnetograms) every minute and full-disk images of the Sun in the wavelength of the Hydrogen–α (Hα) spectral line every 20 seconds. These data products are used for research into the solar magnetic field and chromosphere but are also essential inputs into forecasts of space weather. The NOAA Space Weather Prediction Center (SWPC), the US Airforce 557th Weather Wing, and the NASACommunity Coordinated Modeling Center (CCMC) all use GONG data to predict space weather conditions.
The GONG Project is managed by the National Solar Observatory Integrated Synoptic Program (NISP), which is operated by AURA, Inc. under a cooperative agreement with the National Science Foundation. GONG has been in operation since 1995 and is aging rapidly. To replace it, NSO is proposing to design and build a next-generation Ground-based solar Observing Network, provisionally named ngGONG.[4] In April 2023, NOAA Science Advisory Board reported on the importance of GONG and its successor data source for space weather operations.[5] It concluded that "GONG provides a vital data source for space weather operations, and it is nearing end of life. The ngGONG project is the most straightforward replacement. It will maintain present operational capabilities, and provide observations for future requirements. The time window to complete ngGONG prior to the demise of GONG is closing." The Board recommended that "NOAA/NWS financially support the design phase for ngGONG, to insure the initiation of the project."
↑ Harvey, J. W.; Hill, F.; Hubbard, R. P.; Kennedy, J. R.; Leibacher, J. W.; Pintar, J. A.; Gilman, P. A.; Noyes, R. W.; Title, A. M.; Toomre, J.; Ulrich, R. K.; Bhatnagar, A.; Kennewell, J. A.; Marquette, W.; Patrón, J.; Saá, O.; Yasukawa, E. (31 May 1996). "The Global Oscillation Network Group (GONG) Project". Science. 272 (5266): 1284–1286. doi:10.1126/science.272.5266.1284. PMID8662455.
↑ Pevtsov, Alexei A.; Martinez-Pillet, V.; Gilbert, H.; de Wijn, A. G.; Roth, M.; Gosain, S.; Upton, L. A.; Katsukawa, Y.; Burkepile, J.; Zhang, Jie; Reardon, K. P.; Bertello, L.; Jain, K.; Tripathy, S. C.; Leka, K. D. (2022-11-12). "Helio2024 Science White Paper: ngGONG -- Future Ground-based Facilities for Research in Heliophysics and Space Weather Operational Forecast". arXiv:2211.06712 [astro-ph.IM].
Space weather is a branch of space physics and aeronomy, or heliophysics, concerned with the varying conditions within the Solar System and its heliosphere. This includes the effects of the solar wind, especially on the Earth's magnetosphere, ionosphere, thermosphere, and exosphere. Though physically distinct, space weather is analogous to the terrestrial weather of Earth's atmosphere. The term "space weather" was first used in the 1950s and popularized in the 1990s. Later, it prompted research into "space climate", the large-scale and long-term patterns of space weather.
Mauna Loa is one of five volcanoes that form the Island of Hawaii in the U.S. state of Hawaii in the Pacific Ocean. Mauna Loa is Earth's largest active volcano by both mass and volume. It was historically considered to be the largest volcano on Earth until Tamu Massif was discovered to be larger. Mauna Loa is a shield volcano with relatively gentle slopes, and a volume estimated at 18,000 cubic miles (75,000 km3), although its peak is about 125 feet (38 m) lower than that of its neighbor, Mauna Kea. Lava eruptions from Mauna Loa are silica-poor and very fluid, and tend to be non-explosive.
The Solar and Heliospheric Observatory (SOHO) is a European Space Agency (ESA) spacecraft built by a European industrial consortium led by Matra Marconi Space that was launched on a Lockheed Martin Atlas IIAS launch vehicle on 2 December 1995, to study the Sun. It has also discovered over 5,000 comets. It began normal operations in May 1996. It is a joint project between the European Space Agency (ESA) and NASA. SOHO was part of the International Solar Terrestrial Physics Program (ISTP). Originally planned as a two-year mission, SOHO continues to operate after over 25 years in space; the mission has been extended until the end of 2025, subject to review and confirmation by ESA's Science Programme Committee.
Helioseismology, a term coined by Douglas Gough, is the study of the structure and dynamics of the Sun through its oscillations. These are principally caused by sound waves that are continuously driven and damped by convection near the Sun's surface. It is similar to geoseismology, or asteroseismology, which are respectively the studies of the Earth or stars through their oscillations. While the Sun's oscillations were first detected in the early 1960s, it was only in the mid-1970s that it was realized that the oscillations propagated throughout the Sun and could allow scientists to study the Sun's deep interior. The modern field is separated into global helioseismology, which studies the Sun's resonant modes directly, and local helioseismology, which studies the propagation of the component waves near the Sun's surface.
The Udaipur Solar Observatory (USO) is in Udaipur, Rajasthan in India on an island in the Fateh Sagar Lake. The sky conditions at Udaipur are quite favourable for solar observations. Since the observatory is situated amidst a large mass of water, air turbulence which occurs due to ground heating by sun's rays is decreased. This improves the image quality and accuracy (average between 1-2 arc seconds).
The Haleakalā Observatory, also known as the Haleakalā High Altitude Observatory Site, is Hawaii's first astronomical research observatory. It is located on the island of Maui and is owned by the Institute for Astronomy of the University of Hawaiʻi, which operates some of the facilities on the site and leases portions to other organizations. Tenants include the Air Force Research Laboratory (AFRL) and the Las Cumbres Observatory Global Telescope Network (LCOGTN). At over 3,050 meters (10,010 ft) in altitude, the summit of Haleakalā is above one third of the Earths's troposphere and has excellent astronomical seeing conditions.
The Mauna Loa Observatory (MLO) is an atmospheric baseline station on Mauna Loa, on the island of Hawaii, located in the U.S. state of Hawaii.
Mauna Loa Solar Observatory (MLSO) is a solar observatory located on the slopes of Mauna Loa on the island of Hawaii in the U.S. state of Hawaii. It is operated by the High Altitude Observatory (HAO), a laboratory within the National Center for Atmospheric Research (NCAR). The MLSO sits on property managed by the Mauna Loa Observatory (MLO), which is part of the U.S. Department of Commerce National Oceanic and Atmospheric Administration (NOAA). MLSO was built in 1965.
The US National Center for Atmospheric Research is a US federally funded research and development center (FFRDC) managed by the nonprofit University Corporation for Atmospheric Research (UCAR) and funded by the National Science Foundation (NSF). NCAR has multiple facilities, including the I. M. Pei-designed Mesa Laboratory headquarters in Boulder, Colorado. Studies include meteorology, climate science, atmospheric chemistry, solar-terrestrial interactions, environmental and societal impacts.
The Birmingham Solar Oscillations Network (BiSON) consists of a network of six remote solar observatories monitoring low-degree solar oscillation modes. It is operated by the High Resolution Optical Spectroscopy group of the School of Physics and Astronomy at the University of Birmingham, UK, in collaboration with Sheffield Hallam University, UK. They are funded by the Science and Technology Facilities Council (STFC).
The High Altitude Observatory (HAO) is a laboratory of the US National Center for Atmospheric Research (NCAR). HAO operates the Mauna Loa Solar Observatory on Hawaii and a research institute in Boulder, Colorado.
The 160-minute solar cycle was an apparent periodic oscillation in the solar surface which was observed in a number of early sets of data collected for helioseismology.
The Sagamore Hill Solar Radio Observatory is a solar radio observatory located in Hamilton, Massachusetts, that operates on a daily basis to obtain scientific observations of the Sun. It is a functional component of the Radio Solar Telescope Network (RSTN).
The Radio Solar Telescope Network (RSTN) is a network of solar observatories maintained and operated by the 557th Weather Wing, ACC. The RSTN consists of ground-based observatories in Australia, Italy, Massachusetts, and Hawaii.
The Phoebus group is an international team of European, Japanese and American scientists aiming at detecting the solar g modes. As of October 5, 2009, the group has finally produced a review summarising the work performed over the past 12 years.
The Solar Observing Optical Network (SOON) consists of three U.S. Air Force (USAF) Air Force Weather Agency (AFWA) solar observatories. AFWA operates a solar telescope at each site to monitor solar active regions at optical wavelengths. The National Geophysical Data Center (NGDC) archives histograms of intensity versus area every minute for the active regions. It also archives magnetograms of the magnetic field structure and tachograms of plasma velocities on an irregular schedule.
The Vigil mission, formerly known as Lagrange, is a Space weather weather mission developed by European Space Agency. The mission will provide the ESA Space Weather Office with instruments able to monitor the Sun, its solar corona and interplanetary medium between the Sun and Earth, to provide early warnings of increased solar activity, to identify and mitigate potential threats to society and ground, airborne and space based infrastructure as well as to allow 4 to 5 days space weather forecasts. To this purpose the Vigil mission will place for the first time a spacecraft at Sun-Earth Lagrange point 5 (L5) from where it would get a 'side' view of the Sun, observing regions of solar activity on the solar surface before they turn and face Earth.
Space Weather Follow On-Lagrange 1 (SWFO-L1) is a future spacecraft mission planned to monitor signs of solar storms, which may pose harm to Earth's telecommunication network. The spacecraft will be operated by the National Oceanic and Atmospheric Administration (NOAA), with launch scheduled for 31 March 2025. It is planned to be placed at the Sun–Earth L1 Lagrange point, a location between the Earth and the Sun. This will allow SWFO-L1 to continuously watch the solar wind and energetic particles heading for Earth. SWFO-L1 is an ESPA Class Spacecraft, sized for launch on an Evolved Expendable Launch Vehicle Secondary Payload Adapter (ESPA) Grande ring in addition to the rocket's primary payload. The spacecraft's Solar Wind Instrument Suite (SWIS) which includes three instruments will monitor solar wind, and the Compact Coronagraph (CCOR) will monitor the Sun's surroundings to image coronal mass ejection (CME). A CME is a large outburst of plasma sent from the Sun towards interplanetary space.
Synoptic Optical Long-term Investigations of the Sun (SOLIS) is a synoptic facility for solar observations over a long time frame that is funded by the National Science Foundation (NSF) and designed and built by the National Solar Observatory (NSO). It is operated by the NSO Integrated Synoptic Program (NISP). SOLIS is a single set of three instruments mounted on a common observing platform. The instruments are the 50 cm aperture Vector Spectromagnetograph (VSM), the 8 mm aperture Integrated Sunlight Spectrometer (ISS), and the 14 cm aperture Full-Disk Patrol (FDP). The VSM telescope is a quasi-Ritchey-Chretien design with a primary mirror operating at f/1.6. The ~ 400 W of solar light from the primary is reflected by a secondary mirror fabricated from a single silicon crystal. The final f/6.6 full-disk solar image is focused on a spectrograph slit that is cooled by a flow of chilled water-propylene glycol solution. The mirrors are coated with protected silver. To improve the internal seeing, the VSM is sealed by 74 cm diameter, 6 mm thick fused silica window. Originally, it was filled with helium at about ambient pressure and temperature. In 2014, helium was replaced by nitrogen due to the increasing cost of helium. Due to this change, the image sharpness was slightly degraded.
Irene González Hernández was a Spanish researcher and astrophysicist, promoter of the development of holographic techniques in local helioseismology, which allow detecting solar activity in the non-visible hemisphere of the Sun.
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