Elizabeth Essex-Cohen | |
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| Born | 21 April 1940  Grafton |
| Died | 21 March 2004 (aged 63) |
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| Academic career | |
| Fields | Ionosphere, radio propagation |
| Institutions |
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Elizabeth Essex-Cohen (1940-2004) was an Australian physicist who worked in global positioning satellite physics and was among the first women in Australia to be awarded a PhD in physics.
Elizabeth Annette Essex-Cohen, née Essex, was educated at Grafton High. [1] [2] She subsequently completed a PhD in Physics at Australia's University of New England, investigating ionospheric irregularities under Frank Hibberd, graduating in 1966. [3] [4] Essex-Cohen was the fourth woman in Australia to receive a PhD in physics. [2] [5]
After graduating her PhD, Elizabeth Essex-Cohen worked at University of the West Indies and James Cook University before taking up a lectureship position in space physics at La Trobe University in 1968. [5] She remained at La Trobe for the remainder of her career, though in 1974 and 1978/9 she had simultaneous positions at the US Air Force Geophysics Laboratory as part of her GPS research. [5] Her initial work focused on the use of radio wave reflection to study irregularities in the ionosphere. [6] [7]
Her work on radio transmission through the ionosphere led to some of her best-known work in communications between ground and satellites. In the early US Air force's development of GPS (then called Navstar), she was the only Australian involved in the design. Her collaborations with Australian Antarctic Division and the Co-operative Research Centre for Satellite Systems led to her having a significant role in the development of Australia's FedSat satellite (active 2002-2007 [8] ). [2] [9]
Essex-Cohen became hospitalised for mesothelioma in December 2002. [6] After a brief remission which enabled her to attend a Wireless Science conference, she died in March 2004. [6] Tributes included a special session of the (International) Beacon Satellite Group. [6]
The ionosphere is the ionized part of the upper atmosphere of Earth, from about 48 km (30 mi) to 965 km (600 mi) above sea level, 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 Earth. It also affects GPS signals that travel through this layer.
Space weather is a branch of space physics and aeronomy, or heliophysics, concerned with the time varying conditions within the Solar System, including the solar wind, emphasizing the space surrounding the Earth, including conditions in the magnetosphere, ionosphere, thermosphere, and exosphere. Space weather is distinct from, but conceptually related to, the terrestrial weather of the atmosphere of Earth. The term "space weather" was first used in the 1950s and came into common usage in the 1990s. Later, it was generalized to a "space climate" research discipline, which focuses on general behaviors of longer and larger-scale variabilities and effects.
Constellation Observing System for Meteorology, Ionosphere, and Climate (COSMIC) is a program designed to provide advances in meteorology, ionospheric research, climatology, and space weather by using GPS satellites in conjunction with low Earth orbiting (LEO) satellites. The term "COSMIC" may refer to either the organization itself or the constellation of 6 satellites. The constellation is a joint U.S.-Taiwanese project with major participants including the University Corporation for Atmospheric Research (UCAR), the National Science Foundation, the Naval Research Laboratory (NRL), the Air Force Research Laboratory (AFRL), SRI International on the U.S. side and the National Space Organization (NSPO) on the Taiwanese side.
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, the Solar-Terrestrial Environment Laboratory at Nagoya University, and the Institute for Space Astrophysics and Planetology.
Keith Alexander Nugent FAA is an Australian physicist. He is the Deputy Vice-Chancellor of the Australian National University (ANU) in Canberra.
C/NOFS, or Communications/Navigation Outage Forecasting System was a USAF satellite developed by the Air Force Research Laboratory (AFRL) Space Vehicles Directorate to investigate and forecast scintillations in the Earth's ionosphere. It was launched by an Orbital Sciences Corporation Pegasus-XL launch vehicle at 17:02:48 UTC on 16 April 2008 and decayed on 28 November 2015.
Ionospheric storms are storms which contain varying densities of energised electrons produced from the sun. They are categorised into positive and negative storms, where positive storms have a high density of electrons and negative storms contain a lower density. The total electron content (TEC) is used to measure these densities, and is a key variable used in data to record and compare the intensities of ionospheric storms. Ionospheric storms are caused by geomagnetic storms.
The Jicamarca Radio Observatory (JRO) is the equatorial anchor of the Western Hemisphere chain of Incoherent Scatter Radar (ISR) observatories extending from Lima, Peru to Søndre Strømfjord, Greenland. JRO is the premier scientific facility in the world for studying the equatorial ionosphere. The observatory is about half an hour drive inland (east) from Lima and 10 km from the Central Highway. The magnetic dip angle is about 1°, and varies slightly with altitude and year. The radar can accurately determine the direction of the Earth's magnetic field (B) and can be pointed perpendicular to B at altitudes throughout the ionosphere. The study of the equatorial ionosphere is rapidly becoming a mature field due, in large part, to the contributions made by JRO in radio science.
Satya Prakash is an Indian plasma physicist and a former senior professor at the Physical Research Laboratory. He is known for his studies on Langmuir probes and other contributions in space and plasma sciences. A protégé of Vikram Sarabhai, Satya Prakash is an elected fellow of all the three major Indian science academies such as Indian Academy of Sciences, Indian National Science Academy and National Academy of Sciences, India as well as the Gujarat Science Academy and is a recipient of the Hari Om Ashram Prerit Senior Scientist Award. The Government of India honored him with Padma Shri, the fourth highest Indian civilian award for his contributions to the discipline of Physics, in 1982.
Radio Aurora Explorer (RAX) is the first National Science Foundation sponsored CubeSat mission. The RAX mission is a joint effort between SRI International in Menlo Park, California and the University of Michigan in Ann Arbor, Michigan. The chief scientist at SRI International, Dr. Hasan Bahcivan, led his team at SRI to develop the payload while the chief engineer, Dr. James Cutler, led a team of students to develop the satellite bus in the Michigan Exploration Laboratory. There are currently two satellites in the RAX mission.
Valeria Troitskaya was a Russian geophysicist who is known for her work on Ultra Low Frequency (ULF) waves.
RAX-2 is a CubeSat satellite built as a collaboration between SRI International and students at the University of Michigan College of Engineering. It is the second spacecraft in the RAX mission. The RAX-1 mission ended after approximately two months of operation due to a gradual degradation of the solar panels that ultimately resulted in a loss of power. RAX team members applied the lessons learned from RAX-1 to the design of a second flight unit, RAX-2, which performs the same mission concept of RAX-1 with improved bus performance and additional operational modes. Science measurements are enhanced through interactive experiments with high power ionospheric heaters where FAI will be generated on demand.
Elizabeth "Ella" Finkel AM is a multi-award-winning Australian science journalist, author and communicator. A former biochemist, she has been broadcast on ABC Radio National, and written for publications such as Science, The Lancet, Nature Medicine, The Bulletin, New Scientist, The Age and The Monthly. In 2005 Finkel co-founded the popular science magazine COSMOS, served as Editor in Chief from 2013 to 2018 and she remains its Editor at Large. In 2016 she was made a Member of the Order of Australia (AM) for her science communication work and philanthropy. In 2019 Finkel was awarded a Doctor of Laws honoris causa from Monash University and the Medal of the Australian Society for Medical Research. She now serves as a Vice Chancellor's Fellow at La Trobe University and on advisory committees for La Trobe University Press, the ARC Centre of Excellence for Australian Biodiversity and Heritage (CABAH) and the Melbourne Zoo.
Francisca Nneka Okeke is a Nigerian physicist. She is a Professor of Physics at the University of Nigeria, Nsukka and first female head of a department in the University.
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Jules Aarons was an American space physicist known for his study of radio-wave propagation, and a photographer known for his street photography in Boston.
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Cathryn N. Mitchell is a Professor of Electronic & Electronic Engineering at the University of Bath. She was awarded the 2019 Institute of Physics Edward Appleton Medal and Prize.
Elizabeth Cicely Ridley was a British-American applied mathematician known for her work in numerical quantum chemistry and in climate modeling. The Roble–Dickinson–Ridley code that she and her collaborators created at the National Center for Atmospheric Research was the first general circulation model of the thermosphere.
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