Cynthia A. Cattell | |
---|---|
Alma mater | University of California, Berkeley |
Scientific career | |
Thesis | Magnetic field-aligned currents in the earth's magnetosphere (1980) |
Doctoral advisor | Forrest S. Mozer |
Cynthia Cattell is a space plasma physicist known for her research on solar flares and radiation belts.
Cattell has a B.A. from Hampshire College (1974) [1] and earned her Ph.D. from the University of California, Berkeley in 1980. [2]
As of 2021, Cattell is a professor in the School of Physics and Astronomy at the University of Minnesota. [1]
Cattell's research on electron holes in space helps explain the release of energy from magnetic explosions in space. [3] [4] Cattell has also examined the energization of electrons in Earth's radiation belt [5] and used satellite data to examine the behavior of ions flowing around Earth. [6] [7] Cattell uses her scientific knowledge to present the public with viewing opportunities to see the Northern Lights. [8]
In 2012, Cattell was diagnosed with cancer and was treated with an experimental drug developed by colleagues at University of Minnesota's Masonic Cancer Center. [15] [16] After receiving an increased dosage of an experimental drug there was a reduction in Cattell's tumor and her lymphoma was considered in remission. [17]
An aurora , also commonly known as the northern lights or southern lights, 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.
Van Allen radiation belt is a zone of energetic charged particles, most of which originate from the solar wind, that are captured by and held around a planet by that planet's magnetosphere. Earth has two such belts, and sometimes others may be temporarily created. The belts are named after James Van Allen, who is credited with their discovery.
A coronal mass ejection (CME) is a significant ejection of magnetic field and accompanying plasma mass from the Sun's corona into the heliosphere. CMEs are often associated with solar flares and other forms of solar activity, but a broadly accepted theoretical understanding of these relationships has not been established.
Magnetic reconnection is a physical process occurring in electrically conducting plasmas, in which the magnetic topology is rearranged and magnetic energy is converted to kinetic energy, thermal energy, and particle acceleration. Magnetic reconnection involves plasma flows at a substantial fraction of the Alfvén wave speed, which is the fundamental speed for mechanical information flow in a magnetized plasma.
A terrestrial gamma-ray flash (TGF), also known as dark lightning, is a burst of gamma rays produced in Earth's atmosphere. TGFs have been recorded to last 0.2 to 3.5 milliseconds, and have energies of up to 20 million electronvolts. It is speculated that TGFs are caused by intense electric fields produced above or inside thunderstorms. Scientists have also detected energetic positrons and electrons produced by terrestrial gamma-ray flashes.
The magnetosphere of Saturn is the cavity created in the flow of the solar wind by the planet's internally generated magnetic field. Discovered in 1979 by the Pioneer 11 spacecraft, Saturn's magnetosphere is the second largest of any planet in the Solar System after Jupiter. The magnetopause, the boundary between Saturn's magnetosphere and the solar wind, is located at a distance of about 20 Saturn radii from the planet's center, while its magnetotail stretches hundreds of Saturn radii behind it.
Cluster II is a space mission of the European Space Agency, with NASA participation, to study the Earth's magnetosphere over the course of nearly two solar cycles. The mission is composed of four identical spacecraft flying in a tetrahedral formation. As a replacement for the original Cluster spacecraft which were lost in a launch failure in 1996, the four Cluster II spacecraft were successfully launched in pairs in July and August 2000 onboard two Soyuz-Fregat rockets from Baikonur, Kazakhstan. In February 2011, Cluster II celebrated 10 years of successful scientific operations in space. In February 2021, Cluster II celebrated 20 years of successful scientific operations in space. As of March 2023, its mission has been extended until September 2024. The China National Space Administration/ESA Double Star mission operated alongside Cluster II from 2004 to 2007.
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 Jupiter'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.
Electromagnetic hiss is a naturally occurring Extremely Low Frequency/Very Low Frequency electromagnetic wave that is generated in the plasma of either the Earth's ionosphere or magnetosphere. Its name is derived from its incoherent, structureless spectral properties which, when played through an audio system, sound like white noise.
The Spitzer resistivity is an expression describing the electrical resistance in a plasma, which was first formulated by Lyman Spitzer in 1950. The Spitzer resistivity of a plasma decreases in proportion to the electron temperature as .
Robyn M. Millan is an American experimental physicist, best known for her work on radiation belts that surround the Earth.
Richard Mansergh Thorne was an American physicist and a distinguished professor in the department of atmospheric and oceanic sciences at UCLA. He was known for his contributions to space plasma physics. He was a fellow of the American Geophysical Union.
David Breed Beard was a space physicist, known for "pioneering work on the shapes and structures of planetary magnetospheres, Jovian radio emissions, and comets."
William Henry Matthaeus is an American astrophysicist and plasma physicist. He is known for his research on turbulence in magnetohydrodynamics (MHD) and astrophysical plasmas, for which he was awarded the 2019 James Clerk Maxwell Prize for Plasma Physics.
Wen Li is a space physicist at Boston University. Her research interests include space plasma waves, Earth's radiation belt physics, solar-wind magnetosphere coupling, energetic particle precipitation, and Jovian magnetosphere and aurora: She is a Fellow of the American Geophysical Union.
The Dungey cycle, officially proposed by James Dungey in 1961, is a phenomenon that explains interactions between a planet's magnetosphere and solar wind. Dungey originally proposed a cyclic behavior of magnetic reconnection between Earth's magnetosphere and flux of solar wind. This reconnection explained previously observed dynamics within Earth's magnetosphere. The rate of reconnection in the beginning of the cycle is dependent on the orientation of the interplanetary magnetic field as well as the resultant plasma conditions at the site of reconnection. On Earth, the reconnection cycle takes around 1 hour, but this differs from planet to planet.
Mary Hudson is the Eleanor and Kelvin Smith Distinguished Professor of Physics at Dartmouth College. She is known for her research on the weather patterns that occur due to solar eruptions. She was elected a fellow of the American Geophysical Union in 1984.
James Wynne "Jim" Dungey (1923–2015) was a British space scientist who was pivotal in establishing the field of space weather and made significant contributions to the fundamental understanding of plasma physics.