Canadian Geospace Monitoring

Last updated January 09, 2022

Canadian Geospace Monitoring (CGSM) is a Canadian space science program that was initiated in 2005. CGSM is funded primarily by the Canadian Space Agency, and consists of networks of imagers, meridian scanning photometers, riometers, magnetometers, digital ionosondes, and High Frequency SuperDARN radars. The overarching objective of CGSM is to provide synoptic observations of the spatio-temporal evolution of the ionospheric thermodynamics and electrodynamics at auroral and polar latitudes over a large region of Canada.

Background

The interaction between the solar wind and the Earth's magnetic field has a number of consequences. In brief, these are the formation of the terrestrial Magnetosphere, the provision of energy and matter to the [magnetosphere], and the powering of large-scale electric currents and the closely related phenomenon of the aurora. Near-Earth space physical processes are of interest for economic reasons and for what we can learn about our environment and the cosmos. These processes are connected along the magnetic field to the Earth's ionosphere, where they lead to the aurora, heating, modification of composition, and large-scale plasma motions. All of these ionospheric processes are interesting in their own right. In addition, there is an increasing understanding of the correspondence between ionospheric processes and processes going on further out in near-Earth space. In this way, observations of the ionospheric processes can be used to in turn remote sense dynamics in near-Earth space.

The interaction is significant at sub-auroral, auroral, and polar latitudes where large regions of the magnetosphere are mapped along the magnetic field into relatively small regions of the ionosphere, and where the magnetospheric dynamics are controlled primarily by the plasma rather than the magnetic field. This organization is actually by magnetic rather than by geographic latitude (see Baker and Wing,^[1] and references therein for a description of magnetic vs. geographic coordinates). The aurora, for example, is most frequently observed at magnetic latitudes between roughly 60 and 80 degrees (see Eather^[2]). In the northern hemisphere Canada has the largest land mass at the magnetic latitudes. As a consequence of this so-called "Canadian-advantage", Canada has been a world-leader in ground-based auroral and ionospheric research for decades.

CGSM was envisaged as a national program aimed at obtaining world-class ionospheric observations, and with those in hand directly studying ionospheric dynamics and indirectly the magnetospheric dynamics. It was developed with the guiding principles embodied in five grand challenge science themes. In summary, the science themes are related to the reconnection and convection cycle, magnetospheric instabilities, the formation of the aurora, and the acceleration, transport, and loss of magnetospheric plasma.

Technical Description of the Instrument Network

The CGSM science objectives dictate the observational requirements. In short, the program is designed to specify particle precipitation (aurora), electric currents, and plasma convection in the ionosphere over a large region of Canada. This requires networks of ground-based magnetometers, ionosondes, High-Frequency radars, all-sky imagers, meridian scanning photometers, and riometers. Furthermore, these networks must have overlapping Fields-of-View that span latitudes from the polar region, through the auroral zone, to sub-auroral latitudes. The observations must be of sufficient time and spatial resolution, and of sufficient quality (what determines quality depends on the instrument in question) to allow for new science to be derived from the observations.

Anticipated CGSM stakeholders met in Edmonton in June 2002 to initiate planning for the program. An ambitious plan was settled on, requiring numerous new instruments of various types to be deployed in challenging remote environments. The instruments would need to operate autonomously for long periods, and suffer few breakdowns. Much of the data would need to be recovered in real-time in order for CGSM to develop into an important space weather program, in addition to its space science objectives. New instruments would need to be acquired, outfitted and fielded at existing and new sites. To accomplish this, the team settled on using Telesat Canada's HSi High Speed Satellite Internet system, in conjunction with an information technology infrastructure (basically a glorified local area network with additional capabilities including UPS, GPS, and attached hard-disk storage). Further, members of the team applied to the Canada Foundation for Innovation for funds for new instruments, and were successful on all fronts. The resulting funding enabled the deployment (which is still ongoing) of an additional 8 All-Sky Imagers, 14 fluxgate magnetometers, 8 induction coil magnetometers, and two additional SuperDARN radars (the new "PolarDARN" radars). In addition to facilities that were already in place in 2002 (from the Canadian Space Agency's CANOPUS^[3] program, the Natural Resources Canada CANMOS magnetometer array, and the NSERC supported NORSTAR, SuperDARN, and CADI programs), the final array will certainly meet the scientific requirements.

CGSM began formally with the issuing of contracts to teams at the University of Calgary (photometers, riometers, ASIs), the University of Alberta (simulation, data management, fluxgate magnetometers), and the University of Saskatchewan (SuperDARN HF radars with a subcontract to the University of Western Ontario for digital ionosondes), Natural Resources Canada (space weather operations), and the National Research Council (solar monitor). As well, the University of Calgary developed a new system for managing information technology at the remote sites. In 2007, the CSA called for proposals for the second phase of CGSM. More than 20 proposals were submitted in October, 2007, and contracts were awarded in 2008 for continued and enhanced CGSM activities.

Synergy With Satellite Missions

In a recent review of major Canadian space science projects, Liu et al.^[4] pointed out that CGSM is a unique facility, owing in part to the above-mentioned fact that the bulk of the northern hemisphere auroral region that can be remote sensed from the ground is over Canadian territory, and in part due to a significant investment in new experimental infrastructure that is being and will be realized during the period 2004-2010.

CGSM complements numerous satellite and international ground-based programs. The synergies between CGSM and satellite missions, for example, are very important. Satellites measure the plasma processes at work in the magnetosphere and ionosphere directly using magnetometers, and electric field, plasma wave, and particle detectors. These processes, however, are truly multi-scale, with important scale sizes ranging from kilometers or less to tens of thousands of kilometers. Satellite observations are essential because they are our only direct look at the processes of interest. At the same time, the satellites are like "needles in a haystack", owing to the enormous scale sizes of the magnetospheric system and the fact that all the scales seem to be important in the overall dynamic.

The magnetospheric dynamics are projected along magnetic field lines into the ionosphere and are visible, for example, in changes in the aurora and large-scale ionospheric plasma motions. So we get a two-dimension picture of the magnetospheric dynamics which provides an essential complement to the satellite observations. This synergy and its value in advancing science has been increasingly recognized in recent years. The European Space Agency's Cluster mission included a Ground-Based Working Group that was created with the express purpose of maximizing the impact of coordinated ground-based observations (see Amm et al.,^[5] for a description of the impact of the Cluster Ground-Based Working Group). The five-satellite NASA THEMIS mission launched on February 17, 2006 includes a ground-based component consisting of 20 ground-based observatories (some of which incorporate CGSM magnetometer data), indicating the recognition of the importance of coordinated ground-based observations.

Related Research Articles

The ionosphere is the ionized part of Earth's upper atmosphere, from about 48 km (30 mi) to 965 km (600 mi) altitude, a region that includes the thermosphere and parts of the mesosphere and exosphere. The ionosphere is ionized by solar radiation. It plays an important role in atmospheric electricity and forms the inner edge of the magnetosphere. It has practical importance because, among other functions, it influences radio propagation to distant places on the Earth.

An aurora, also known as the polar lights or aurora polaris, is a natural light display in Earth's sky, predominantly seen in high-latitude regions. Auroras display dynamic patterns of brilliant lights that appear as curtains, rays, spirals, or dynamic flickers covering the entire sky.

A geomagnetic storm, also known as a magnetic storm, is a temporary disturbance of the Earth's magnetosphere caused by a solar wind shock wave and/or cloud of magnetic field that interacts with the Earth's magnetic field.

IMAGE is a NASA Medium Explorer mission that studied the global response of the Earth's magnetosphere to changes in the solar wind. It was believed lost but as of August 2018 might be recoverable. It was launched 25 March 2000, at 20:34:43.929 UTC, by a Delta II launch vehicle from Vandenberg Air Force Base on a two-year mission. Almost six years later, it unexpectedly ceased operations in December 2005 during its extended mission and was declared lost. The spacecraft was part of NASA's Sun-Earth Connections Program, and its data has been used in over 400 research articles published in peer-reviewed journals. It had special cameras that provided various breakthroughs in understanding the dynamics of plasma around the Earth. The principal investigator was Jim Burch of the Southwest Research Institute.

A Birkeland current is a set of currents that flow along geomagnetic field lines connecting the Earth's magnetosphere to the Earth's high latitude ionosphere. In the Earth's magnetosphere, the currents are driven by the solar wind and interplanetary magnetic field and by bulk motions of plasma through the magnetosphere. The strength of the Birkeland currents changes with activity in the magnetosphere. Small scale variations in the upward current sheets accelerate magnetospheric electrons which, when they reach the upper atmosphere, create the Auroras Borealis and Australis. In the high latitude ionosphere, the Birkeland currents close through the region of the auroral electrojet, which flows perpendicular to the local magnetic field in the ionosphere. The Birkeland currents occur in two pairs of field-aligned current sheets. One pair extends from noon through the dusk sector to the midnight sector. The other pair extends from noon through the dawn sector to the midnight sector. The sheet on the high latitude side of the auroral zone is referred to as the Region 1 current sheet and the sheet on the low latitude side is referred to as the Region 2 current sheet.

Ørsted is Denmark's first satellite, named after Hans Christian Ørsted (1777–1851), a Danish physicist and professor at the University of Copenhagen, who discovered electromagnetism in 1820.

The following is a chronology of discoveries concerning the magnetosphere.

The Super Dual Auroral Radar Network (SuperDARN) is an international scientific radar network consisting of 35 high frequency (HF) radars located in both the Northern and Southern Hemispheres. SuperDARN radars are primarily used to map high-latitude plasma convection in the F region of the ionosphere, but the radars are also used to study a wider range of geospace phenomena including field aligned currents, magnetic reconnection, geomagnetic storms and substorms, magnetospheric MHD waves, mesospheric winds via meteor ionization trails, and interhemispheric plasma convection asymmetries. The SuperDARN collaboration is composed of radars operated by JHU/APL, Virginia Tech, Dartmouth College, the Geophysical Institute at the University of Alaska Fairbanks, the Institute of Space and Atmospheric Studies at the University of Saskatchewan, the University of Leicester, Lancaster University, La Trobe University, and the Solar-Terrestrial Environment Laboratory at Nagoya University.

The plasmasphere, or inner magnetosphere, is a region of the Earth's magnetosphere consisting of low-energy (cool) plasma. It is located above the ionosphere. The outer boundary of the plasmasphere is known as the plasmapause, which is defined by an order of magnitude drop in plasma density. In 1963 American scientist Don Carpenter and Soviet astronomer Konstantin Gringauz proved the plasmasphere and plasmapause's existence from the analysis of very low frequency (VLF) whistler wave data. Traditionally, the plasmasphere has been regarded as a well behaved cold plasma with particle motion dominated entirely by the geomagnetic field and, hence, co-rotating with the Earth.

Time History of Events and Macroscale Interactions during Substorms (THEMIS) mission began in February 2007 as a constellation of five NASA satellites to study energy releases from Earth's magnetosphere known as substorms, magnetic phenomena that intensify auroras near Earth's poles. The name of the mission is an acronym alluding to the Titan Themis.

The magnetosphere of Jupiter is the cavity created in the solar wind by the planet's magnetic field. Extending up to seven million kilometers in the Sun's direction and almost to the orbit of Saturn in the opposite direction, Jupiter's magnetosphere is the largest and most powerful of any planetary magnetosphere in the Solar System, and by volume the largest known continuous structure in the Solar System after the heliosphere. Wider and flatter than the Earth's magnetosphere, Jupiter's is stronger by an order of magnitude, while its magnetic moment is roughly 18,000 times larger. The existence of Jupiter's magnetic field was first inferred from observations of radio emissions at the end of the 1950s and was directly observed by the Pioneer 10 spacecraft in 1973.

The Global Geospace Science (GGS) Polar satellite was a NASA science spacecraft designed to study the polar magnetosphere and aurorae. It was launched into orbit in February 1996, and continued operations until the program was terminated in April 2008. The spacecraft remains in orbit, though it is now inactive. Polar is the sister ship to GGS Wind.

Dynamics Explorer was a NASA mission, launched on 3 August 1981, and terminated on 28 February 1991. It consisted of two unmanned satellites, DE-1 and DE-2, whose purpose was to investigate the interactions between plasmas in the magnetosphere and those in the ionosphere. The two satellites were launched together into polar coplanar orbits, which allowed them to simultaneously observe the upper and lower parts of the atmosphere.

The Injun program was a series of six satellites designed and built by researchers at the University of Iowa to observe various radiation and magnetic phenomena in the ionosphere and beyond.

A substorm, sometimes referred to as a magnetospheric substorm or an auroral substorm, is a brief disturbance in the Earth's magnetosphere that causes energy to be released from the "tail" of the magnetosphere and injected into the high latitude ionosphere. Visually, a substorm is seen as a sudden brightening and increased movement of auroral arcs. Substorms were first described in qualitative terms by Kristian Birkeland which he called polar elementary storms. Sydney Chapman used the term substorm about 1960 which is now the standard term. The morphology of aurora during a substorm was first described by Syun-Ichi Akasofu in 1964 using data collected during the International Geophysical Year.

The impact of the solar wind onto the magnetosphere generates an electric field within the inner magnetosphere - the convection field-. Its general direction is from dawn to dusk. The co-rotating thermal plasma within the inner magnetosphere drifts orthogonal to that field and to the geomagnetic field B_o. The generation process is not yet completely understood. One possibility is viscous interaction between solar wind and the boundary layer of the magnetosphere (magnetopause). Another process may be magnetic reconnection. Finally, a hydromagnetic dynamo process in the polar regions of the inner magnetosphere may be possible. Direct measurements via satellites have given a fairly good picture of the structure of that field. A number of models of that field exists.

Solar wind Magnetosphere Ionosphere Link Explorer (SMILE) is a planned joint venture mission between the European Space Agency and the Chinese Academy of Sciences. SMILE will image for the first time the magnetosphere of the Sun in soft X-rays and UV during up to 40 hours per orbit, improving our understanding of the dynamic interaction between the solar wind and Earth's magnetosphere. The prime science questions of the SMILE mission are

CSES , or Zhangheng, is a Chinese–Italian space mission dedicated to monitoring electromagnetic field and waves, plasma parameters and particle fluxes induced by natural sources and artificial emitters in the near-Earth space. Austria contributes to one of the magnetometers.

Dynamics Explorer 1 was a NASA mission, high-altitude mission, launched on 3 August 1981, and terminated on 28 February 1991. It consisted of two satellites, DE-1 and DE-2, whose purpose was to investigate the interactions between plasmas in the magnetosphere and those in the ionosphere. The two satellites were launched together into polar coplanar orbits, which allowed them to simultaneously observe the upper and lower parts of the atmosphere.

Dynamics Explorer 2 was a NASA mission, low-altitude mission, launched on 3 August 1981. It consisted of two satellites, DE-1 and DE-2, whose purpose was to investigate the interactions between plasmas in the magnetosphere and those in the ionosphere. The two satellites were launched together into polar coplanar orbits, which allowed them to simultaneously observe the upper and lower parts of the atmosphere.

References

↑ Baker, K., and S. Wing, A new magnetic coordinate system for conjugate studies at high latitudes, J. Geophys. Res., 94(A7), 9139–9143, 1989.
↑ Eather, Robert H., Majestic Lights: The Aurora in Science, History, and The Arts. Washington, DC: American Geophysical Union. ISBN 0-87590-215-4. (323 pages), 1980.
↑ Rostoker et al., Canopus — A ground-based instrument array for remote sensing the high latitude ionosphere during the ISTP/GGS program, Space Sci. Rev., Volume 71, Numbers 1-4, pages 743-760, 1995
↑ Liu, W., et al., Solar and Space Physics in the Era of International Living With a Star, Physics in Canada, Volume 61, No. 1., 2005.
↑ Amm, O., E. F. Donovan, H. Frey, M. Lester, R. Nakamura, J. A. Wild, A. Aikio, M. Dunlop, K. Kauristie, A. Marchaudon, I. W. McCrea, H. J. Opgenoorth, and A. Strømme, Coordinated studies of the geospace environment using Cluster, satellite and ground-based data: an interim review, Annales Geophysicae, 23:2129-2170, 2005.

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[1] Baker, K., and S. Wing, A new magnetic coordinate system for conjugate studies at high latitudes, J. Geophys. Res., 94(A7), 9139–9143, 1989.

[2] Eather, Robert H., Majestic Lights: The Aurora in Science, History, and The Arts. Washington, DC: American Geophysical Union. ISBN 0-87590-215-4. (323 pages), 1980.

[3] Rostoker et al., Canopus — A ground-based instrument array for remote sensing the high latitude ionosphere during the ISTP/GGS program, Space Sci. Rev., Volume 71, Numbers 1-4, pages 743-760, 1995

[4] Liu, W., et al., Solar and Space Physics in the Era of International Living With a Star, Physics in Canada, Volume 61, No. 1., 2005.

[5] Amm, O., E. F. Donovan, H. Frey, M. Lester, R. Nakamura, J. A. Wild, A. Aikio, M. Dunlop, K. Kauristie, A. Marchaudon, I. W. McCrea, H. J. Opgenoorth, and A. Strømme, Coordinated studies of the geospace environment using Cluster, satellite and ground-based data: an interim review, Annales Geophysicae, 23:2129-2170, 2005.

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