Karen Aplin is a British atmospheric and space physicist. She is currently a professor at the University of Bristol. [1] [2] Aplin has made significant contributions to interdisciplinary aspects of space and terrestrial science, in particular the importance of electrical effects on planetary atmospheres. [3] [4] [5] She was awarded the 2021 James Dungey Lectureship of the Royal Astronomical Society. [6]
After attending The High School, Gloucester, Aplin completed a BSc in Natural Sciences at Durham University in 1997. [7] She was president of Durham University Orchestral Society and received the Norah C. Bowes bequest for the arts. [8] She completed her PhD in experimental atmospheric physics in the Department of Meteorology at the University of Reading in 2000. She took up research posts at the University of Hertfordshire and the STFC Rutherford Appleton Laboratory, working on aspects of space and atmospheric instrumentation, before becoming head of the physics laboratories at Oxford University in 2009. In 2018 she moved to the University of Bristol.
Aplin's research has focussed on innovative instrumentation as applied to problems in space and atmospheric science, in particular electrical effects and measurements. She currently maintains the Snowdon space-weather observatory. [9] She has performed experimental work on the atmospheric effects of ions formed by cosmic rays, but has been keen to stress that the formed "particles are too small to act as cloud condensation nuclei", [10] and thus there is unlikely to be a strong cosmic-ray link to global cloud cover.
Her work on atmospheric electricity also extends to the link between volcanoes, lightning and radon gas, [11] [12] [13] and to other solar system bodies, in particular the ultraviolet and galactic cosmic ray effects on Neptune's atmosphere. [14] [15] [16]
In a similarly interdisciplinary spirit, Aplin has researched the influence of the climate and weather on western orchestral composers. [17] [18]
2021: James Dungey Lectureship of the Royal Astronomical Society. [6] [19]
2019: Visiting professor at the University of Bath (previously visiting senior research fellow)
2015 – present: Editor of the Journal of Electrostatics
2009 – present: Editor for the open-access journal History of Geo- and Space Sciences [20]
An observatory is a location used for observing terrestrial, marine, or celestial events. Astronomy, climatology/meteorology, geophysics, oceanography and volcanology are examples of disciplines for which observatories have been constructed. Historically, observatories were as simple as containing an astronomical sextant or Stonehenge.
Atmospheric science is the study of the Earth's atmosphere and its various inner-working physical processes. Meteorology includes atmospheric chemistry and atmospheric physics with a major focus on weather forecasting. Climatology is the study of atmospheric changes that define average climates and their change over time climate variability. Aeronomy is the study of the upper layers of the atmosphere, where dissociation and ionization are important. Atmospheric science has been extended to the field of planetary science and the study of the atmospheres of the planets and natural satellites of the Solar System.
A whistler is a very low frequency (VLF) electromagnetic (radio) wave generated by lightning. Frequencies of terrestrial whistlers are 1 kHz to 30 kHz, with maximum frequencies usually at 3 kHz to 5 kHz. Although they are electromagnetic waves, they occur at audio frequencies, and can be converted to audio using a suitable receiver. They are produced by lightning strikes where the impulse travels along the Earth's magnetic field lines from one hemisphere to the other. They undergo dispersion of several kHz due to the slower velocity of the lower frequencies through the plasma environments of the ionosphere and magnetosphere. Thus they are perceived as a descending tone which can last for a few seconds. The study of whistlers categorizes them into Pure Note, Diffuse, 2-Hop, and Echo Train types.
An atmosphere is a layer of gas or layers of gases that envelop a planet, and is held in place by the gravity of the planetary body. A planet retains an atmosphere when the gravity is great and the temperature of the atmosphere is low. A stellar atmosphere is the outer region of a star, which includes the layers above the opaque photosphere; stars of low temperature might have outer atmospheres containing compound molecules.
The solar cycle, also known as the solar magnetic activity cycle, sunspot cycle, or Schwabe cycle, is a nearly periodic 11-year change in the Sun's activity measured in terms of variations in the number of observed sunspots on the Sun's surface. Over the period of a solar cycle, levels of solar radiation and ejection of solar material, the number and size of sunspots, solar flares, and coronal loops all exhibit a synchronized fluctuation from a period of minimum activity to a period of a maximum activity back to a period of minimum activity.
Atmospheric electricity describes the electrical charges in the Earth's atmosphere. The movement of charge between the Earth's surface, the atmosphere, and the ionosphere is known as the global atmospheric electrical circuit. Atmospheric electricity is an interdisciplinary topic with a long history, involving concepts from electrostatics, atmospheric physics, meteorology and Earth science.
Atmospheric escape is the loss of planetary atmospheric gases to outer space. A number of different mechanisms can be responsible for atmospheric escape; these processes can be divided into thermal escape, non-thermal escape, and impact erosion. The relative importance of each loss process depends on the planet's escape velocity, its atmosphere composition, and its distance from its star. Escape occurs when molecular kinetic energy overcomes gravitational energy; in other words, a molecule can escape when it is moving faster than the escape velocity of its planet. Categorizing the rate of atmospheric escape in exoplanets is necessary to determining whether an atmosphere persists, and so the exoplanet's habitability and likelihood of life.
A Forbush decrease is a rapid decrease in the observed galactic cosmic ray intensity following a coronal mass ejection (CME). It occurs due to the magnetic field of the plasma solar wind sweeping some of the galactic cosmic rays away from Earth. The term Forbush decrease was named after the American physicist Scott E. Forbush, who studied cosmic rays in the 1930s and 1940s.
A plasmoid is a coherent structure of plasma and magnetic fields. Plasmoids have been proposed to explain natural phenomena such as ball lightning, magnetic bubbles in the magnetosphere, and objects in cometary tails, in the solar wind, in the solar atmosphere, and in the heliospheric current sheet. Plasmoids produced in the laboratory include field-reversed configurations, spheromaks, and in dense plasma focuses.
Henrik Svensmark is a physicist and professor in the Division of Solar System Physics at the Danish National Space Institute in Copenhagen. He is known for his work on the hypothesis that fewer cosmic rays are an indirect cause of global warming via cloud formation.
A global atmospheric electrical circuit is the continuous movement of atmospheric charge carriers, such as ions, between an upper conductive layer and surface. The global circuit concept is closely related to atmospheric electricity, but not all atmospheres necessarily have a global electric circuit. The basic concept of a global circuit is that through the balance of thunderstorms and fair weather, the atmosphere is subject to a continual and substantial electrical current.
Neptune is the eighth and farthest planet from the Sun. It is the fourth-largest planet in the Solar System by diameter, the third-most-massive planet, and the densest giant planet. It is 17 times the mass of Earth, and slightly more massive than its near-twin Uranus. Neptune is denser and physically smaller than Uranus because its greater mass causes more gravitational compression of its atmosphere. Being composed primarily of gases and liquids, it has no well-defined solid surface. The planet orbits the Sun once every 164.8 years at an orbital distance of 30.1 astronomical units. It is named after the Roman god of the sea and has the astronomical symbol , representing Neptune's trident.
Volcanic lightning is an electrical discharge caused by a volcanic eruption rather than from an ordinary thunderstorm. Volcanic lightning arises from colliding, fragmenting particles of volcanic ash, which generate static electricity within the volcanic plume, leading to the name dirty thunderstorm. Moist convection currents and ice formation also drive the eruption plume dynamics and can trigger volcanic lightning. Unlike ordinary thunderstorms, volcanic lightning can also occur when there are no ice crystals in the ash cloud.
Michael John Rycroft is an ionospheric physicist.
Space climate is the long-term variation in solar activity within the heliosphere, including the solar wind, the Interplanetary magnetic field (IMF), and their effects in the near-Earth environment, including the magnetosphere of Earth and the ionosphere, the upper and lower atmosphere, climate, and other related systems. The scientific study of space climate is an interdisciplinary field of space physics, solar physics, heliophysics, and geophysics. It is thus conceptually related to terrestrial climatology, and its effects on the atmosphere of Earth are considered in climate science.
The small planet radius gap is an observed scarcity of planets with radii between 1.5 and 2 times Earth's radius, likely due to photoevaporation-driven mass loss. A bimodality in the Kepler exoplanet population was first observed in 2011 and attributed to the absence of significant gas atmospheres on close-in, low-mass planets. This feature was noted as possibly confirming an emerging hypothesis that photoevaporation could drive atmospheric mass loss This would lead to a population of bare, rocky cores with smaller radii at small separations from their parent stars, and planets with thick hydrogen- and helium-dominated envelopes with larger radii at larger separations. The bimodality in the distribution was confirmed with higher-precision data in the California-Kepler Survey in 2017, which was shown to match the predictions of the photoevaporative mass-loss hypothesis later that year.
Jo Ann Cram Joselyn is an astrogeophysicist. She was the first woman to receive a doctorate from the University of Colorado's astrogeophysics program, and has advocated for the importance of women's leadership in the sciences.
Sarah Anna Matthews is a British physicist. She is professor and head of solar physics at University College London's Mullard Space Science Laboratory (MSSL). She is also chairperson of UK Solar Physics.
Margaret Ann ("Peggy") Shea is a space scientist known for research on the connections between cosmic radiation and Earth's magnetic field.
James Wynne 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.