WorldWideScience

Sample records for aeronomy

  1. Current understanding of the aeronomy of Mars

    Science.gov (United States)

    Nagy, Andrew F.; Grebowsky, Joseph M.

    2015-12-01

    This paper provides a short overview of our current understanding of the upper atmosphere/ionosphere of Mars including the escaping neutral atmosphere to space that plays a key role in the current state of the Mars upper atmosphere. The proper definition of the word "aeronomy" relates to the upper atmosphere where ionization is important. Currently there is a paucity of measurements of the internal physical structure of the Martian upper atmosphere/ionosphere. Much that we know has been deduced from theoretical models that predict many more things than thus far measured. The newest Mars orbital missions, the US MAVEN and Indian MOM missions, just beginning their science analyses, will provide the measurements needed to fully characterize the aeronomy of Mars.

  2. The Long, Bumpy Road to a Mars Aeronomy Mission (Invited)

    Science.gov (United States)

    Grebowsky, J. M.; Luhmann, J. G.; Bougher, S. W.; Jakosky, B. M.

    2013-12-01

    With the advent of the space age, early focus was put into characterizing the Earth's upper atmosphere with aeronomy missions. These missions were designed to study the upper atmosphere region of a planet where the ionosphere is produced with particular attention given to the composition, properties and motion of atmosphere constituents. In particular a very successful US series of Atmosphere Explorer aeronomy spacecraft (1963-1977) was implemented. This upper atmosphere region is the envelope that all energy from the sun must penetrate and is recognized as an inseparable part of a planet's entire atmosphere. Venus was the next planet to have its upper atmosphere/ionosphere deeply probed via the Pioneer Venus Orbiter (1978-1986) that carried a complement of instruments similar to some flown on the Atmosphere Explorers. The planet which humans have long set their imagination on, Mars, has yet to be subjected to the same detailed upper atmosphere perusal until now, with MAVEN. Not that attempts have been wanting. More than 30 spacecraft launches to Mars were attempted, but half were not successful and those that attained orbit came far short of attaining the same level of knowledge of the Martian upper atmosphere. Other countries had planned Mars aeronomy missions that didn't bear fruit - e.g. Mars-96 and Nozomi and the US did studies for two missions, Mars Aeronomy Orbiter and MUADEE, that never were implemented. This is about to change. NASA's Scout Program singled out two aeronomy missions in its final competition and the selected mission, MAVEN, will fly with the needed sophistication of instruments to finally probe and understand the top of Mars' atmosphere. Was this late selection of a NASA aeronomy mission to Mars a philosophy change in US priorities or was it an accident of planning and budget constraints? Was it driven by the developing knowledge that Mars really had an early atmosphere environment conducive to life and that an aeronomy mission is indeed

  3. International Association of Geomagnetism and Aeronomy IAGA 11. Scientific Assembly

    International Nuclear Information System (INIS)

    IAGA 11th Scientific Assembly. The International Association of Geomagnetism and Aeronomy (IAGA) is one of the eight associations of the International Union of Geodesy and Geophysics (IUGG). IAGA is a non-governmental body founded to promote and coordinate studies of the electrical and magnetic properties of the Earth's core, mantle and crust, of the middle and upper atmosphere, of the ionosphere and magnetosphere, and the Sun, the solar wind, the planets and interplanetary bodies. IAGA is organised into five Divisions and two Inter divisional (ID) commissions: Division I: Internal Magnetic Field, Division II: Aeronomic Phenomena, Division III: Magnetospheric Phenomena, Division IV: Solar Wind and Interplanetary Field, Division V: Geomagnetic Observatories, Surveys and Analyses, IDCH: Commission on History, ICDC: Commission on Developing Countries. The IAGA 11th Scientific Assembly is held in Sopron (Hungary), from 23 August to 30 August 2009. (S.I.)

  4. Attendees “roasted” at Space Physics and Aeronomy dinner

    Science.gov (United States)

    Russell, C. T.

    The Space Physics and Aeronomy Section's annual dinner was held during the Fall AGU meeting in December at San Francisco's Wu Kong restaurant. The Planetology section joined the SPA section for this year's event, but that's not why tickets for the dinner sold out so early this year; it was because of the many members hoping to receive one of the prestigious awards presented at the dinner each year.The first award presented was a serious one. The Fred Scarf award—which recognizes the year's most outstanding Ph.D. thesis—was received by UCLA's Vassilis Angelopoulos, who did his undergraduate work at the University of Thessaloniki in Greece [Angelopoulos, 1993]. SPA President Janet Luhmann also deserves congratulations for being able to pronounce Thessaloniki.

  5. Spread F – an old equatorial aeronomy problem finally resolved?

    Directory of Open Access Journals (Sweden)

    R. F. Woodman

    2009-05-01

    Full Text Available One of the oldest scientific topics in Equatorial Aeronomy is related to Spread-F. It includes all our efforts to understand the physical mechanisms responsible for the existence of ionospheric F-region irregularities, the spread of the traces in a night-time equatorial ionogram – hence its name – and all other manifestations of the same. It was observed for the first time as an abnormal ionogram in Huancayo, about 70 years ago. But only recently are we coming to understand the physical mechanisms responsible for its occurrence and its capricious day to day variability. Several additional techniques have been used to reveal the spatial and temporal characteristics of the F-region irregularities responsible for the phenomenon. Among them we have, in chronological order, radio star scintillations, trans-equatorial radio propagation, satellite scintillations, radar backscatter, satellite and rocket in situ measurements, airglow, total electron content techniques using the propagation of satellite radio signals and, recently, radar imaging techniques. Theoretical efforts are as old as the observations. Nevertheless, 32 years after their discovery, Jicamarca radar observations showed that none of the theories that had been put forward could explain them completely. The observations showed that irregularities were detected at altitudes that were stable according to the mechanisms proposed. A breakthrough came a few years later, again from Jicamarca, by showing that some of the "stable" regions had become unstable by the non-linear propagation of the irregularities from the unstable to the stable region of the ionosphere in the form of bubbles of low density plasma. A problem remained, however; the primary instability mechanism proposed, an extended (generalized Rayleigh-Taylor instability, was too slow to explain the rapid development seen by the observations. Gravity waves in the neutral background have been proposed as a seeding mechanism to

  6. Aeronomy, a 20th Century emergent science: the role of solar Lyman series

    Directory of Open Access Journals (Sweden)

    G. Kockarts

    Full Text Available Aeronomy is, by definition, a multidisciplinary science which can be used to study the terrestrial atmosphere, as well as any planetary atmosphere and even the interplanetary space. It was officially recognized in 1954 by the International Union of Geodesy and Geophysics. The major objective of the present paper is to show how aeronomy developed since its infancy. The subject is so large that a guide-line has been chosen to see how aeronomy affects our atmospheric knowledge. This guideline is the solar Lyman alpha radiation which has different effects in the solar system. After a short description of the origins of aeronomy the first observations of this line are summarized since the beginning of the space age. Then the consequences of these observations are analyzed for the physics and chemistry of the neutral terrestrial atmosphere. New chemical processes had to be introduced, as well as new transport phenomena. Solar Lyman alpha also influences the structure of the Earth’s ionosphere, particularly the D-region. In the terrestrial exosphere, solar Lyman alpha scattered resonantly by atomic hydrogen is at present the only way to estimate this constituent in an almost collisionless medium. Since planetary atmospheres also contain atomic hydrogen, the Lyman alpha line has been used to deduce the abundance of this constituent. The same is true for the interplanetary space where Lyman alpha observations can be a good tool to determine the concentration. The last section of the paper presents a question which is intended to stimulate further research in aeronomy.

    Key words. Atmospheric composition and structure (middle atmosphere – composition and chemistry; thermosphere – composition and chemistry – history of geophysics (atmospheric sciences

  7. (?) The Air Force Geophysics Laboratory: Aeronomy, aerospace instrumentation, space physics, meteorology, terrestrial sciences and optical physics

    Science.gov (United States)

    McGinty, A. B.

    1982-04-01

    Contents: The Air Force Geophysics Laboratory; Aeronomy Division--Upper Atmosphere Composition, Middle Atmosphere Effects, Atmospheric UV Radiation, Satellite Accelerometer Density Measurement, Theoretical Density Studies, Chemical Transport Models, Turbulence and Forcing Functions, Atmospheric Ion Chemistry, Energy Budget Campaign, Kwajalein Reference Atmospheres, 1979, Satellite Studies of the Neutral Atmosphere, Satellite Studies of the Ionosphere, Aerospace Instrumentation Division--Sounding Rocket Program, Satellite Support, Rocket and Satellite Instrumentation; Space Physics Division--Solar Research, Solar Radio Research, Environmental Effects on Space Systems, Solar Proton Event Studies, Defense Meteorological Satellite Program, Ionospheric Effects Research, Spacecraft Charging Technology; Meteorology Division--Cloud Physics, Ground-Based Remote-Sensing Techniques, Mesoscale Observing and Forecasting, Design Climatology, Aircraft Icing Program, Atmospheric Dynamics; Terrestrial Sciences Division--Geodesy and Gravity, Geokinetics; Optical Physics Division--Atmospheric Transmission, Remote Sensing, INfrared Background; and Appendices.

  8. Geomagnetism and Aeronomy activities in Italy during IGY, 1957/58

    Directory of Open Access Journals (Sweden)

    Lucilla Alfonsi

    2009-06-01

    Full Text Available In 2007 several events were organized to celebrate the fiftieth anniversary of the International Geophysical Year
    (IGY, 1957-1958. The celebrations will last until 2009 and are taking place within different contexts: the International
    Polar Year (IPY, the International Heliophysical Year (IHY, the electronic Geophysical Year (eGY
    and the International Year of Planet Earth (IYPE.
    IGY offered a very appropriate and timely occasion to undertake a series of coordinated observations of various
    geophysical phenomena all over the globe. Italy took part in the broad international effort stimulated by IGY. In
    fact, Italy participated in observations and studies in many of the proposed scientific areas, in particular Geomagnetism
    and Aeronomy. The Istituto Nazionale di Geofisica (ING started the installation of observatories,
    and updated and ensured continuous recording of geophysical observations. Geomagnetism, ionospheric
    physics, seismology, and other geophysical disciplines, were advanced. Although much of the work was undertaken
    in Italy, some attention was also devoted to other areas of the world, in particular Antarctica, where Italy
    participated in seismological observations. This paper gives a summary of the Geomagnetism and Ionospheric
    Physics activities within IGY. Furthermore, we highlight the importance of this historical event and its outcomes
    for the improvement of geophysical observations and the post-IGY growth of scientific investigations in Italy.

  9. Satellite mission Aeronomy of Ice in the Mesosphere (AIM) partners with formal and informal education programs to study clouds on the edge of space

    Science.gov (United States)

    Robinson, D. Q.; Maggi, B. H.

    2004-12-01

    The satellite-based research mission "Aeronomy of Ice In the Mesosphere" (AIM), has developed an exciting partnership of formal and informal education programs that will connect students and the public to the unique scientific aspects of the mission. The AIM satellite mission is dedicated to providing a scientific basis for understanding why Polar Mesospheric Clouds (PMCs) form and vary. PMCs are sometimes known as Noctilucent Clouds (NLCs) or "night shinning" clouds because of their visibility at dawn and dusk. The visible manifestation of PMCs provides a unique opportunity for Education and Public Outreach. The AIM outreach programs will utilize the beautiful images of "clouds on the edge of space" as a tool to motivate students and the public to increase their knowledge and understanding about issues surrounding changes in our atmosphere. In an effort to provide formal and informal outreach opportunities worldwide, AIM has developed a partnership with the GLOBE program. GLOBE is a network of schools, science centers, and clubs from over 105 countries where participants collect scientific data according to precise protocols and enter the data into a central database allowing both scientists and students to utilize the data. The collaboration between AIM and GLOBE will involve participants in collecting and utilizing NLC data worldwide. This partnership will provide a mechanism for sustaining AIM education opportunities for both formal and informal education venues in the future. Included in the formal education component of AIM outreach is the implementation of two educator workshops that will establish partnerships between the mission and classrooms nationwide. The educator workshops will be held in Alaska due to the optimal location for viewing NLCs. Participants attending the workshops will be chosen from a national pool allowing teachers working with students in southern latitudes an opportunity to experience the excitement of working with data that can only

  10. I. Airglow on Mars: Model predictions for the oxygen IR atmospheric band at 1.27 micrometers, the hydroxyl radical Meinel bands and the hydroxyl radical A-X band system. II. Physical and chemical aeronomy of HD 209458b

    Science.gov (United States)

    Garcia Munoz, Antonio

    The first part of this dissertation is concerned with model predictions of airglow from the O2 IR atmospheric band at 1.27 mum, the OH Meinel bands and the OH A-X band system in the low-latitude neutral atmosphere of Mars. As an observable feature, airglow provides a means to remotely probe the composition, dynamics and energetics of the Martian atmosphere. The daytime emission from the O2 IR atmospheric band, a direct result of ozone photodissociation, has long been known to be a prominent emission of the Martian airglow. The motivation for pursuing the modelling of the nighttime components of the O2 IR atmospheric band and the OH Meinel bands is the potential of these two processes for characterizing the atomic oxygen profile in the 50-80 km region of the atmosphere. Likewise, the OH A-X band system may be useful to constrain the abundance of the hydroxyl radical on the illuminated side of the planet below 60 km. Both, O and OH are indicators of the photochemical state of the atmosphere. The results reported herein are expected to serve as guidelines for prospective observations of the atmosphere of Mars. The second part of the dissertation investigates the physical and chemical aeronomy of HD 209458b. The discovery of this extrasolar planet by radial velocity measurements was announced in 2000. Shortly afterwards, the inference of the mean planetary density from transit observations indicated the plausible gaseous nature of the planet. Later in-transit spectrally-resolved photometric observations revealed a cloud of hydrogen, carbon and oxygen atoms extending to a few planetary radii above the surface of the planet, which has been interpreted as evidence for an escaping atmosphere around HD 209458b. At an orbital distance of 0.05 AU, intense EUV stellar irradiation may lead to the massive escape of the atmosphere. In this work, the composition, escape and energy balance of the atmosphere are consistently modelled. Escape rates and abundances of the main hydrogen

  11. TIDI observations relating to low latitude aeronomy

    Science.gov (United States)

    Niciejewski, R.; Killeen, T.; Kafkalidis, J.; Wu, Q.; Skinner, W.; Solomon, S.; Ortland, D.; Gell, D.; Gablehouse, D.; Johnson, R.

    2003-04-01

    The TIDI instrument aboard the TIMED satellite has been observing the neutral winds in the upper atmosphere on a routine basis since early January 2002. The instrument simultaneously samples the thin limb of the Earth with four separate telescopes providing two forward views and two rearward views, one of each on either side of the orbital path. At equator crossings, these two side views are separated by about 30 degrees of longitude at the tangent point altitude, or 2 hours of local time. Thus, on any orbit TIDI obtains two horizontal vector winds at the dayside equator crossing and two on the nightside equator crossing as well as for all low latitudes. This is significantly greater than the data output of either the HRDI or the DE-2 satellite observations. This paper will describe the climatology that has been obtained by the TIDI instrument since early 2002 for low latitudes. The precession rate of TIMED supports two month averaging of data sets in order to sample all local solar time. Tidal structure is evident in the resulting zonal and meridional winds for mesosphere and lower thermosphere altitudes.

  12. Tidi Observations Relating to High Latitude Aeronomy

    Science.gov (United States)

    Gell, D.; Niciejewski, R.; Killeen, T.; Wu, Q.; Skinner, W.; Solomon, S.; Ortland, D.; Kafkalidis, J.; Gablehouse, D.; Johnson, R.

    2003-12-01

    Unique observations of the horizontal neutral winds at high latitudes in the altitude range 60 to 180 km have been performed by TIDI (Thermosphere Ionosphere Doppler Interferometer) since January 2002. The satellite orbit is such that the TIDI field of view includes latitudes to both the north pole and the south pole. Though high latitude neutral wind measurements have been obtained from space with the DE-2 satellite and the UARS satellite, TIDI is the first instrument to sample the mesosphere and the lower thermosphere up to and including both polar regions on a long-term basis. Ground based studies have previously reported a strong semi-diurnal tide in the mesosphere over Resolute, Canada. This paper will describe the climatology that has been obtained by the TIDI instrument since early 2002 for high latitudes. The precession rate of TIMED supports two month averaging of data sets in order to sample all local solar time.

  13. NASA 3D Models: Aeronomy of Ice

    Data.gov (United States)

    National Aeronautics and Space Administration — AIM is a two-year mission to study Polar Mesospheric Clouds (PMCs), the Earth's highest clouds, which form an icy membrane 50 miles (80.4 km) above the surface at...

  14. Aeronomy from the International Space Station

    Science.gov (United States)

    Christensen, A. B.; Budzien, S. A.; Bishop, R. L.; Stephan, A. W.

    2010-12-01

    The lessons learned with The Remote Atmospheric and Ionospheric Detection System (RAIDS) a new NASA experiment studying the Earth's thermosphere and ionosphere from a vantage point on the International Space Station (ISS) will be reviewed. The RAIDS mission focuses on the coupling and transition from the coldest part of the atmosphere, the mesopause near 85 km, up to the hottest regions of the thermosphere above 300 km. Built jointly by the Naval Research Laboratory (NRL) and The Aerospace Corporation, RAIDS also is serving as a pathfinder experiment for atmospheric remote sensing aboard the ISS. The 51.6 deg. orbital inclination and roughly 340 km orbital altitude of the ISS required tailoring atmospheric science objectives appropriate for low- and mid-latitude observations. Orbital precession enables observations over a range of local time and solar illumination conditions, but also causes the orbital plane to intersect the Sun roughly monthly, requiring a temporary shutdown of the RAIDS sensors. Extensive station structures near the field-of-regard pose a risk of scattered light contamination which must be mitigated through good baffling of optical sensors. Activities aboard the manned station, including attitude perturbations from spacecraft dockings and construction activities, occasionally disrupt observations. A significant challenge for limb-viewing RAIDS was ISS pitch oscillations up to ±0.75 deg. per orbit associated with solar array rotation, but NASA adjusted the station’s flight characteristics to provide ±0.2 deg. pitch stability for RAIDS. Jitter and vibration at the extremity of the ISS have not been a concern for RAIDS. Finally, manned environments are notoriously dirty with respect to contamination-sensitive optical instruments, but after twelve months of continuous operation RAIDS does not exhibit any unusual degradation in sensor performance.

  15. Electron temperature and density probe for small aeronomy satellites

    Energy Technology Data Exchange (ETDEWEB)

    Oyama, K.-I. [Plasma and Space Science Center, National Cheng Kung University, Tainan, Taiwan (China); Institute of Space and Plasma Sciences, National Cheng Kung University, Tainan, Taiwan (China); International Center for Space Weather Study and education, Kyushu University, Fukuoka (Japan); Hsu, Y. W.; Jiang, G. S.; Chen, W. H.; Liu, W. T. [Plasma and Space Science Center, National Cheng Kung University, Tainan, Taiwan (China); Cheng, C. Z.; Fang, H. K. [Plasma and Space Science Center, National Cheng Kung University, Tainan, Taiwan (China); Institute of Space and Plasma Sciences, National Cheng Kung University, Tainan, Taiwan (China)

    2015-08-15

    A compact and low power consumption instrument for measuring the electron density and temperature in the ionosphere has been developed by modifying the previously developed Electron Temperature Probe (ETP). A circuit block which controls frequency of the sinusoidal signal is added to the ETP so that the instrument can measure both T{sub e} in low frequency mode and N{sub e} in high frequency mode from the floating potential shift of the electrode. The floating potential shift shows a minimum at the upper hybrid resonance frequency (f{sub UHR}). The instrument which is named “TeNeP” can be used for tiny satellites which do not have enough conductive surface area for conventional DC Langmuir probe measurements. The instrument also eliminates the serious problems associated with the contamination of satellite surface as well as the sensor electrode.

  16. Planet-B: A Japanese Mars aeronomy observer

    Science.gov (United States)

    Tsuruda, K.

    1992-01-01

    An introduction is given to a Japanese Mars mission (Planet-B) which is being planned at the Institute of Space and Aeronautical Science (ISAS), Japan. Planet-B aims to study the upper atmosphere of Mars and its interaction with the solar wind. The launch of Planet-B is planned for 1996 on a new launcher, M-L, which is being developed at ISAS. In addition to the interaction with the solar wind, the structure of the Martian upper atmosphere is thought to be controlled by the meteorological condition in the lower atmosphere. The orbit of Planet-B was chosen so that it will pass two important regions, the region where the solar wind interacts with the Martian upper atmosphere and the tail region where ion acceleration is taking place. Considering the drag due to the Martian atmosphere, the periapsis altitude of 150 km and apoapsis of 10 Martian radii are planned. The orbit plane will be nearly parallel to the ecliptic plane. The altitude of the spacecraft will be spin stabilized and its spin axis will be controlled to the point of the earth. The dry weight of the spacecraft will be about 250 kg, including the scientific payload which consists of a magnetometer, plasma instruments, HF sounder, UV imaging spectrometer, and lower atmosphere monitor.

  17. Comparative Aeronomy: Molecular Ionospheres at Earth and Mars

    Science.gov (United States)

    Mendillo, Michael; Trovato, Jeffrey; Narvaez, Clara; Mayyasi, Majd A.; Moore, Luke; Vogt, Marissa F.; Fallows, Kathryn J.; Withers, Paul; Martinis, Carlos

    2016-10-01

    The ionospheres in our solar system vary not only in their electron densities, but also in the dominance of atomic versus molecular ions at their altitudes of peak plasma density. With the exception of Earth's F-layer composed of atomic oxygen ions and electrons, all other planets have their peak ionospheric layers composed of molecular ions and electrons embedded in a dense neutral atmosphere. At Mars, both of its ionospheric layers have molecular ions, with the M1-layer at a lower altitude than the more robust M2-layer above it. The terrestrial ionosphere has a prominent region of molecular ions (the E-layer) below the dominant F-layer. In this paper, we explore the production and loss of molecular ion layers observed under the same solar irradiance conditions at Mars and Earth. We compare observations of M1 and M2 electron densities with terrestrial ionosonde data for the peak densities of the E- and F-layers during low, moderate and high solar flux conditions. The sub-solar peak densities of molecular ion layers have high correlations at each planet, as well as between planets, even though they are produced by separate portions of the solar spectrum. We use photo-chemical-equilibrium theory for layers produced by soft X-rays (M1 and E) versus the M2-layer produced by extreme ultraviolet (EUV) to identify the key parameters that cause similarities and differences. The yield of our comparative study points to the roles of secondary ionization and temperature dependent plasma recombination rates as areas most in need of further study at each planet.

  18. Space Physics & Aeronomy: Space Science Decadal Surveys Available

    Science.gov (United States)

    Smith, David

    The final, edited texts of two recent advisory committee reports are now available upon request from the National Research Council's Space Studies Board. The reports, New Frontiers in the Solar System: An Integrated Exploration Strategy, the report of the Solar System Exploration Survey (Michael J. S. Belton, Belton Space Exploration Initiatives, chair) and The Sun to the Earth-and Beyond: A Decadal Research Strategy in Solar and Space Physics, the report of the Solar and Space Physics Survey (Louis J. Lanzerotti, Lucent Technologies, chair) are available in a variety of media as follows: New Frontiers in the Solar System: Currently available as a book, a CD-ROM, or online at http://books.nap.edu/html/newfrontiers/0309084954.pdf. We are also taking advanced orders for copies of New Frontiers in Solar System Exploration, a 32-page, full-color booklet describing for a popular audience the principal mission recommendations of the Solar System Exploration Survey.

  19. Morrow, Reiff, Receive 2013 Space Physics and Aeronomy Richard Carrington Awards: Response

    Science.gov (United States)

    Reiff, Patricia H.

    2014-08-01

    It is a special privilege to receive this award honoring Richard Carrington's discovery of what we now call space weather. It is particularly appropriate that this award also recognizes Cherilynn Morrow, who 20 years ago made a presentation to the Space Science Advisory Committee on Jeff Rosendhal's idea of mission-based E/PO. We worked together, bringing that idea to the successful, but threatened, network it is today. For me, learning and teaching go hand in hand—as we publish our findings for our peers, we should also repay the public investment in our research with accurate, understandable results. My interest in space science was sparked by a father-daughter course in astronomy sponsored by the Brownies at the Oklahoma City Planetarium and kindled by the Bell Labs production The Strange Case of the Cosmic Rays directed by Frank Capra. Knowing that planetarium shows and educational movies can change lives, I have devoted a large portion of my last 25 years to creating software, shows, and portable planetariums to inspire and engage youth. This has not been a one-person effort, of course. My work Cherilynn Ann Morrow would have been impossible without the collaboration of Carolyn Sumners, vice president of the Houston Museum of Natural Science. Our museum kiosk and planetarium control software would not have happened without the skill and perseverance of my chief programmer, Colin Law. Jim Burch has been first a mentor and then a colleague on both the research and outreach sides of my career. I share this honor with a long line of highly talented students and postdocs who have contributed science content and outreach efforts. Most importantly, without the support of my husband, Tom Hill, I would not have had the time and freedom to build an educational network while continuing research and raising a family. I thank AGU for bestowing this honor.

  20. SWUIS-A: A Versatile, Low-Cost UV/VIS/IR Imaging System for Airborne Astronomy and Aeronomy Research

    Science.gov (United States)

    Durda, Daniel D.; Stern, S. Alan; Tomlinson, William; Slater, David C.; Vilas, Faith

    2001-01-01

    We have developed and successfully flight-tested on 14 different airborne missions the hardware and techniques for routinely conducting valuable astronomical and aeronomical observations from high-performance, two-seater military-type aircraft. The SWUIS-A (Southwest Universal Imaging System - Airborne) system consists of an image-intensified CCD camera with broad band response from the near-UV to the near IR, high-quality foreoptics, a miniaturized video recorder, an aircraft-to-camera power and telemetry interface with associated camera controls, and associated cables, filters, and other minor equipment. SWUIS-A's suite of high-quality foreoptics gives it selectable, variable focal length/variable field-of-view capabilities. The SWUIS-A camera frames at 60 Hz video rates, which is a key requirement for both jitter compensation and high time resolution (useful for occultation, lightning, and auroral studies). Broadband SWUIS-A image coadds can exceed a limiting magnitude of V = 10.5 in <1 sec with dark sky conditions. A valuable attribute of SWUIS-A airborne observations is the fact that the astronomer flies with the instrument, thereby providing Space Shuttle-like "payload specialist" capability to "close-the-loop" in real-time on the research done on each research mission. Key advantages of the small, high-performance aircraft on which we can fly SWUIS-A include significant cost savings over larger, more conventional airborne platforms, worldwide basing obviating the need for expensive, campaign-style movement of specialized large aircraft and their logistics support teams, and ultimately faster reaction times to transient events. Compared to ground-based instruments, airborne research platforms offer superior atmospheric transmission, the mobility to reach remote and often-times otherwise unreachable locations over the Earth, and virtually-guaranteed good weather for observing the sky. Compared to space-based instruments, airborne platforms typically offer substantial cost advantages and the freedom to fly along nearly any groundtrack route for transient event tracking such as occultations and eclipses.

  1. Short Planning Turn-Around Time and High Flexibility of the Swedish Astronomy/Aeronomy Satellite Odin

    Science.gov (United States)

    Jakobsson, B.; Karlsson, T.; Nylund, M.; Olsson, T.; Vinterhav, E.

    2002-01-01

    The Swedish small satellite Odin combines two different scientific disciplines, astronomy and atmospheric research. It has a 3-axis stabilized, zero momentum, attitude control system that operates in two different modes, an inertial pointing astronomy mode and an atmospheric mode providing pointing/scanning of the Earth limb. The reference attitude for the atmospheric mode is created by a versatile reference attitude generator, providing also capability for observing and tracking any celestial or solar system objects. The absolute pointing requirements in the scientific modes are 15 arc-seconds inertial pointing and 1.2 arc-minutes in atmospheric mode reconstructed attitude. One part of the Odin mission is to observe the formation of the ozone holes at the poles in spring and fall and another is to observe moving celestial objects such as comets. The unpredictability of when such observation opportunities occur together with rapidly changing scientific demands put high requirements on a short turn- around time for the Operations Cycle - science demand, planning and command generation, reconstruction of attitude history, feedback and delivery to scientists. A small efficient team, including also members that was deeply involved with and responsible for the design and development of the system, has been a key to provide this a short turn-around time for the Operations Cycle. It is possible to safely reconfigure the satellite for either of two disciplines with short notice and have a reconstructed attitude available to the users shortly after the observations have been done. The small efficient team together with modular software based on MATLAB also facilitates in rapidly meeting new demands on the planning and attitude reconstruction from the users.

  2. Geomagnetic Storm Sudden Commencements

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Storm Sudden Commencements (ssc) 1868 to present: STORM1 and STORM2 Lists: (Some text here is taken from the International Association of Geomagnetism and Aeronomy...

  3. International Union of Geodesy and Geophysics, General Assembly, 18th, Hamburg, West Germany, August 15-27, 1983, U.S. National Committee Report

    Science.gov (United States)

    James, D. E.

    1983-03-01

    Studies related to planetology are discussed, taking into account planetary science during the time from 1979 to 1982, planetary atmospheres, outer planets satellites, the geology of the terrestrial planets, planetary ring systems, planetary radar astronomy, asteroids and comets, and progress toward the origin of the solar system. Solar-planetary relationships related to aeronomy are examined, giving attention to the dynamics of the earth's thermosphere, ionospheric electrodynamics and irregularities, U.S. contributions to auroral aeronomy, neutral and ion composition of the thermosphere, the aeronomy of the inner planets, middle atmospheric electrodynamics, minor constituents in the stratosphere and mesosphere, and middle atmosphere dynamics. Other topics explored are concerned with solar-planetary relationships involving cosmic rays, and magnetospheric physics. For individual items see A83-38266 to A83-38300

  4. Italian research on Antarctic atmosphere: 1st workshop. Ricerche italiane sull'atmosfera antartica: 1o workshop

    Energy Technology Data Exchange (ETDEWEB)

    Colacino, M. (ed.); Giovannelli, G. (ed.); Stefanutti, L. (ed.)

    1989-01-01

    The papers and reports, presented at this 1st workshop on 'Italian research on antarctic atmosphere', deal with several main topics: meteorology and climatology, aerosol and tropospheric clouds, planetary boundary layer, chemical-physic stratospheric property, aeronomy. They define the stage of development of Italian research in this area after 3 years of activity in Antarctica.

  5. Summaries of physical research in the geosciences

    Energy Technology Data Exchange (ETDEWEB)

    1986-09-01

    The summaries in this document describe the scope of the individual programs and detail the research performed during 1984-1985. The Geosciences Research Program includes research in geology, petrology, geophysics, geochemistry, hydrology, solar-terrestrial relationships, aeronomy, seismology, and natural resource analysis, including their various subdivisions and interdisciplinary areas.

  6. International Geomagnetic Reference Field

    DEFF Research Database (Denmark)

    Finlay, Chris; Maus, S.; Beggan, C. D.;

    2010-01-01

    The eleventh generation of the International Geomagnetic Reference Field (IGRF) was adopted in December 2009 by the International Association of Geomagnetism and Aeronomy Working Group V‐MOD. It updates the previous IGRF generation with a definitive main field model for epoch 2005.0, a main field...

  7. International Geomagnetic Reference Field: the 12th generation

    DEFF Research Database (Denmark)

    Thébault, Erwan; Finlay, Chris; Beggan, Ciarán D.;

    2015-01-01

    The 12th generation of the International Geomagnetic Reference Field (IGRF) was adopted in December 2014 by the Working Group V-MOD appointed by the International Association of Geomagnetism and Aeronomy (IAGA). It updates the previous IGRF generation with a definitive main field model for epoch...

  8. Ground-based, Sounding Rocket and Satellite Observations of the Upper Atmosphere and Ionosphere in the Arctic

    OpenAIRE

    2013-01-01

    The Geophysical Institute (GI) at the University of Alaska, Fairbanks carries out a wide range of geophysical studies using Alaska as a natural laboratory. The research arm of the GI is organized around natural phenomena in the sub-arctic and structured into seven groups including: Volcanology, Seismology; Tectonics and Sedimentation; Snow, Ice and Permafrost; Remote Sensing; Atmospheric Science; and Space Physics and Aeronomy. The latter of these groups carries out investigations of the midd...

  9. Radar observations of artificial E-region field-aligned irregularities

    OpenAIRE

    E. Nossa; D. L. Hysell; Fallen, C. T.; B. J. Watkins

    2009-01-01

    Artificial E region field aligned plasma density irregularities (FAIs) were generated using HAARP in four different experimental modes and observed with a coherent scatter radar imager located 450 km to the southwest where it could detect field-aligned backscatter. The experiments were conducted in July of 2008, during the Polar Aeronomy and Radio Science Summer School (PARS), during quiet conditions in the daytime when the E layer was dense and absorption was modest. Th...

  10. International geomagnetic reference field 1980: a report by IAGA Division I working group.

    Science.gov (United States)

    Peddie, N.W.

    1982-01-01

    Describes the recommendations of the working group, which suggested additions to IGRF because of the cumulative effect of the inevitable uncertainties in the secular variation models which had led to unacceptable inaccuracies in the IGRF by the late 1970's. The recommendations were accepted by the International Association of Geomagnetism and Aeronomy on August 15, 1981 at the 4th Scientific Assembly, Edinburgh. An extended table sets out spherical harmonic coefficients of the IGRF 1980.-R.House

  11. DLR’S MOBILE ROCKET BASE – 47 YEARS OF MICROGRAVITY AND TECHNICAL EXPERIMENTS ON SUBORBITAL FLIGHTS

    OpenAIRE

    Schmidt, Alexander; Stamminger, Andreas; Turner, Peter

    2014-01-01

    Mobile Rocket Base (MORABA), a division of the Space Operations and Astronaut Training Department of DLR (Deutsches Zentrum für Luft- und Raumfahrt) provides the national and international scientific community with the opportunity to prepare and implement rocket- and balloon-borne experiments. The fields of research include aeronomy, geophysics, material science and hypersonic research and are conducted in cooperation with a variety of international partners. MORABA offers a number of mech...

  12. French space program: report to Cospar

    Energy Technology Data Exchange (ETDEWEB)

    1975-01-01

    Programs and results obtained are reviewed for all French laboratories working in areas of research related to space. Main topics include lunar specimen studies; spectroscopic planetology; space radiation; ionospheric and magnetospherics; aeronomy; meteorology, comprising the Meteosat program and the Eole experiment and earth resources investigations; geodesy; and geodynamics-research covering space biology and exobiology is also discussed. French satellites and sounding rockets are listed, as well as French experiments onboard foreign spacecraft. (GRA)

  13. Solar Spectrum (SOLSPEC) measurement from 180 to 3000 nanometers

    Science.gov (United States)

    Thuiller, G.; Simon, P. C.

    1988-01-01

    The SOLSPEC experiment, planned for the Atmospheric Laboratory for Applications and Science (ATLAS 1) NASA mission, is described. The purpose of this experiment is the measurement of the absolute solar irradiances in the wavelength range from 180 to 3000 nm and the variabilities of the solar irradiances in this wavelength range. Measurements of the irradiances and variabilities are used in: (1) solar-terrestrial/planetary relationships, in particular aeronomy of the stratosphere and mesosphere; (2) climatoglogy; and (3) solar physics.

  14. Ground Testing and Flight Demonstration of Charge Management of Insulated Test Masses Using UV LED Electron Photoemission

    OpenAIRE

    Saraf, Shailendhar; Buchman, Sasha; Balakrishnan, Karthik; Lui, Chin Yang; Soulage, Michael; Faied, Dohy; Hanson, John (John J.); Ling, Kuok; Jaroux, Belgacem; AlRashed, Abdullah; Nassban, Badr Al; Suwaidan, Badr Al; Harbi, Mohammed Al; Salamah, Badr Bin; Othman, Mohammed Bin

    2016-01-01

    The UV LED mission demonstrates the precise control of the potential of electrically isolated test masses that is essential for the operation of space accelerometers and drag free sensors. Accelerometers and drag free sensors were and remain at the core of geodesy, aeronomy, and precision navigation missions as well as gravitational science experiments and gravitational wave observatories. Charge management using photoelectrons generated by the 254 nm UV line of Hg was first demonstrated on G...

  15. A Novel Concept to Explore the Coupling of the Solar-Terrestrial System

    Science.gov (United States)

    Spann, James F.

    2014-01-01

    A revolutionary opportunity to explore the consequences of reconnection in the ionosphere as never before will be presented. It is a revolutionary opportunity to explore key Aeronomy emissions on a global scale with spatial and temporal resolution not possible today. For example, observations of the signature of dayside merging and nightside reconnection that are reflected in the auroral oval evolution during disturbed periods and quiet times, will be described; observations that will open a window of discovery for coupling phenomena within Geospace and with the solar wind. The description of this new concept will be presented, and its impact and contribution to understanding magnetic merging will be discussed.

  16. Proceedings of the IRI task force activity 2000

    International Nuclear Information System (INIS)

    This internal report of the International Center for Theoretical Physics (ICTP) contains presentations delivered during the International Reference Ionosphere Task Force Activity 2000 which took place at the Abdus Salam ICTP during July 2000. The 2000 Task Force Activity is the seventh successful encounter of specialists organized by the URSI-COSPAR IRI Working Group and the Aeronomy and Radiopropagation Laboratory of the ICTP of Trieste, Italy. The main topic of this task force activity was the modeling of the topside ionosphere and the development of strategies for modeling of ionospheric variability

  17. Proceedings of the IRI task force activity 1996

    International Nuclear Information System (INIS)

    The report contains the programme, summary and write up of 12 presentations delivered during the International Reference Ionosphere (IRI) Task Force Activity 96 that have taken place at the ICTP Trieste during August 1996. The 1996 task force has focussed on the model descriptions for the bottomside F-region including the F1 layer and started the consideration of the topside ionosphere. This was the third successful encounter of specialists organized by the URSI-COSPAR IRI Working Group and the Aeronomy and Radiopropagation Laboratory of the International Centre for Theoretical Physics of Trieste, Italy. Each presentation was indexed separately. Refs, figs, tabs

  18. Proceedings of the IRI Task Force Activity 2002. 1. ed

    International Nuclear Information System (INIS)

    This ICTP Internal Report contains the list of papers presented, activity reports and the write up of a number of presentations delivered during the International Reference Ionosphere (IRI) Task Force Activity 2002 which took place at the Abdus Salam ICTP during August 2002. The 2002 Task Force Activity is the ninth successful encounter of specialists organized by the URSI-Cospar IRI Working Group and the Aeronomy and Radiopropagation Laboratory of the Abdus Salam International Centre for Theoretical Physics of Trieste, Italy. The main topics of the meeting were ionosphere variability and topside ionosphere

  19. Summaries of physical research in the geosciences

    Energy Technology Data Exchange (ETDEWEB)

    1983-09-01

    The Department of Energy supports research in the geosciences in order to provide a sound foundation of fundamental knowledge in those areas of earth, atmospheric, and solar-terrestrial sciences that are germane to the Department of Energy's many missions. The summaries in the document describe the scope of the individual programs and detail the research performed during 1982 to 1983. The Geoscience Research Program includes research in geology, petrology, geophysics, geochemistry, hydrology, solar-terrestrial relationships, aeronomy, seismology, and natural resource analysis, including the various subdivisions and interdisciplinary areas. All such research is related either directly or indirectly to the Department of Energy's technological needs.

  20. Atomic processes and application in honour of David R. Bates' 60th birthday

    CERN Document Server

    Burke, P G

    2013-01-01

    Atomic Processes and Applications is a collection of review articles that discusses major atomic and molecular processes and their applications to upper atmospheric physics and to astrophysics. The book also serves as a 60th birthday tribute to Dr. David R. Bates. The coverage of the text includes the overview of stratospheric aeronomy; upper atmosphere of the earth; and problems in atmospheric pollution. The book also deals with technical and highly specialized issues including photoionization of atomic systems; atomic structure and oscillator strengths; and atomic scattering computations. Th

  1. Summaries of physical research in the geosciences

    International Nuclear Information System (INIS)

    The Department of Energy supports research in the geosciences in order to provide a sound foundation of fundamental knowledge in those areas of earth, atmospheric, and solar-terrestrial sciences that are germane to the Department of Energy's many missions. The summaries describe the scope of the individual programs and detail the research performed during 1980 to 1981. The Geosciences Research Program includes research in geology, petrology, geophysics, geochemistry, hydrology, solar-terrestrial relationships, aeronomy, seismology, and natural resource analysis, including the various subdivisions and interdisciplinary areas

  2. Summaries of physical research in the geosciences

    Energy Technology Data Exchange (ETDEWEB)

    1987-09-01

    The Department of Energy supports research in the geosciences in order to provide a sound foundation of fundamental knowledge in those areas that are germane to the Department of Energy's many missions. The summaries in this document, prepared by the investigators, describe the scope of the individual programs. The Geoscience Research Program includes research in geology, petrology, geophysics, geochemistry, solar-terrestrial relationships, aeronomy, seismology, and natural resource analysis, including their various subdivisions and interdisciplinary areas. All such research is related either directly or indirectly to the Department of Energy's technological needs.

  3. Summaries of physical research in the geosciences

    Energy Technology Data Exchange (ETDEWEB)

    1981-10-01

    The Department of Energy supports research in the geosciences in order to provide a sound foundation of fundamental knowledge in those areas of earth, atmospheric, and solar-terrestrial sciences that are germane to the Department of Energy's many missions. The summaries describe the scope of the individual programs and detail the research performed during 1980 to 1981. The Geosciences Research Program includes research in geology, petrology, geophysics, geochemistry, hydrology, solar-terrestrial relationships, aeronomy, seismology, and natural resource analysis, including the various subdivisions and interdisciplinary areas.

  4. Detection of ionospheric Alfvén resonator signatures in the equatorial ionosphere

    Science.gov (United States)

    Simões, Fernando; Klenzing, Jeffrey; Ivanov, Stoyan; Pfaff, Robert; Freudenreich, Henry; Bilitza, Dieter; Rowland, Douglas; Bromund, Kenneth; Liebrecht, Maria Carmen; Martin, Steven; Schuck, Peter; Uribe, Paulo; Yokoyama, Tatsuhiro

    2012-11-01

    The ionosphere response resulting from minimum solar activity during cycle 23/24 was unusual and offered unique opportunities for investigating space weather in the near-Earth environment. We report ultra low frequency electric field signatures related to the ionospheric Alfvén resonator detected by the Communications/Navigation Outage Forecasting System (C/NOFS) satellite in the equatorial region. These signatures are used to constrain ionospheric empirical models and offer a new approach for monitoring ionosphere dynamics and space weather phenomena, namely aeronomy processes, Alfvén wave propagation, and troposphere-ionosphere-magnetosphere coupling mechanisms.

  5. New Space Weather and Nonlinear Waves and Processes Prize announced for 2013

    Science.gov (United States)

    Thompson, Victoria

    2012-01-01

    At the 2011 Fall Meeting in San Francisco, Calif., AGU announced the creation of a new award: the Space Weather and Nonlinear Waves and Processes Prize. The prize, which is being made possible by a generous contribution from longtime AGU members and NASA Jet Propulsion Laboratory (JPL), California Institute of Technology, scientists Bruce Tsurutani and Olga Verkhoglyadova, will recognize an AGU member scientist and will come with a $10,000 award. Tsurutani has served as a researcher with JPL since 1972 and is currently a senior research scientist. He was also the president of AGU's Space Physics and Aeronomy section from 1990 to 1992 and is a recipient of AGU's John Adam Fleming Medal, given “for original research and technical leadership in geomagnetism, atmospheric electricity, aeronomy, space physics, and related sciences.” Verkhoglyadova served as a professor of space physics in the Department of Astrophysics and Space Physics at Taras Shevchenko National University of Kyiv, in the Ukraine, prior to coming to the United States. Their leadership and dedication to AGU and to their field are apparent in their passion for this prize.

  6. Imaging Spectrograph as a Tool to Enhance the Undergraduate Student Research Experience

    Science.gov (United States)

    Williams, B.; Nielsen, K.; Johnson, S.

    2015-12-01

    Undergraduate students often engage in research activities that are part of a larger project outlined by research faculty, while it is less common for students to explore and define their own research project. The later has been shown to have tremendous impact on the learning outcome of the students and provide a stronger sense of pride and ownership of the research project. It is unrealistic to expect starting undergraduate students to define transformative research projects. However, with the proper training and guidance student-driven transformative research is possible for upper division students. We have instituted a student research paradigm with focus on the development of student research skills in coordination with their course progress. We present here a specific student project that engage students in aeronomy research activities and provide them with a solid base to establish their own research projects for senior year. The core of the project is an imaging spectrograph, which is constructed, tested, and calibrated by the students. The instrument provides unique opportunities student research projects across subject such as optics, quantum mechanics, and how these subjects are applied in the geosciences of aeronomy and space physics.

  7. Solar EUV irradiance from the San Marco ASSI - A reference spectrum

    Science.gov (United States)

    Schmidtke, Gerhard; Woods, Thomas N.; Worden, John; Rottman, Gary J.; Doll, Harry; Wita, Claus; Solomon, Stanley C.

    1992-11-01

    The only satellite measurement of the solar EUV irradiance during solar cycle 22 has been obtained with the Airglow Solar Spectrometer Instrument (ASSI) aboard the San Marco 5 satellite flown in 1988. The ASSI in-flight calibration parameters are established by using the internal capabilities of ASSI and by comparing ASSI results to the results from other space-based experiments on the ASSI calibration rocket and the Solar Mesospheric Explorer (SME). A solar EUV irradiance spectrum derived from ASSI observations on November 10, 1988 is presented as a reference spectrum for moderate solar activity for the aeronomy community. This ASSI spectrum should be considered as a refinement and extension of the solar EUV spectrum published for the same day by Woods and Rottman (1990).

  8. The Antarctic Submillimeter Telescope and Remote Observatory (AST/RO)

    CERN Document Server

    Stark, A A; Balm, S P; Bania, T M; Bolatto, A D; Chamberlin, R A; Engargiola, G; Huang, M; Ingalls, J G; Jacobs, K; Jackson, J M; Kooi, J W; Lane, A P; Lo, K Y; Marks, R D; Martin, C L; Mumma, D; Ojha, R P; Schieder, R; Staguhn, J G; Stutzki, J; Walker, C K; Wilson, R W; Wright, G A; Zhang, X; Zimmermann, P; Zimmermann, R E; Stark, Antony A.; Bally, John; Balm, Simon P.; Bolatto, Alberto D.; Chamberlin, Richard A.; Engargiola, Gregory; Huang, Maohai; Ingalls, James G.; Jacobs, Karl; Jackson, James M.; Kooi, Jacob W.; Lane, Adair P.; Marks, Rodney D.; Martin, Christopher L.; Mumma, Dennis; Ojha, Roopesh; Schieder, Rudolf; Staguhn, Johannes; Stutzki, Juergen; Walker, Christopher K.; Wilson, Robert W.; Wright, Gregory A.; Zhang, Xiaolei; Zimmermann, Peter; Zimmermann, Ruediger

    2000-01-01

    AST/RO, a 1.7 m diameter telescope for astronomy and aeronomy studies at wavelengths between 200 and 2000 microns, was installed at the South Pole during the 1994-1995 Austral summer. The telescope operates continuously through the Austral winter, and is being used primarily for spectroscopic studies of neutral atomic carbon and carbon monoxide in the interstellar medium of the Milky Way and the Magellanic Clouds. The South Pole environment is unique among observatory sites for unusually low wind speeds, low absolute humidity, and the consistent clarity of the submillimeter sky. Four heterodyne receivers and three acousto-optical spectrometers are installed. Telescope pointing, focus, and calibration methods as well as the unique working environment and logistical requirements of the South Pole are described.

  9. New approaches to planetary exploration - Spacecraft and information systems design

    Science.gov (United States)

    Diaz, A. V.; Neugebauer, M.; Stuart, J.; Miller, R. B.

    1983-01-01

    Approaches are recommended for use by the NASA Solar System Exploration Committee (SSEC) in lowering the costs of planetary missions. The inclusion of off-the-shelf hardware, i.e., configurations currently in use for earth orbits and constructed on a nearly assembly-line basis, is suggested. Alterations would be necessary for the thermal control, power supply, telecommunications equipment, and attitude sensing in order to be serviceable as a planetary observer spacecraft. New technology can be developed only when cost reduction for the entire mission would be realized. The employment of lower-cost boost motors, or even integrated boost motors, for the transfer out of earth orbit is indicated, as is the development of instruments that do not redundantly gather the same data as previous planetary missions. Missions under consideration include a Mars geoscience climatology Orbiter, a lunar geoscience Orbiter, a near-earth asteroid rendezvous, a Mars aeronomy Orbiter, and a Venus atmospheric probe.

  10. Let's Build Tomorrow's Talent Today

    Science.gov (United States)

    Burch, James L.

    2008-08-01

    My association with AGU since graduate student days has benefited my scientific research and career in numerous ways. Through AGU I have met intelligent colleagues, forged important partnerships that led to significant research projects, published most of my research results, received recognition from my peers, and been enriched by my roles as Geophysical Research Letters editor in chief, Space Physics and Aeronomy section president, and chair of the Committee on Public Affairs and the Meetings Committee. Like many of you, I am an AGU junkie. Yet I worry that the abundant opportunities we have enjoyed in Earth and space science research may not be as available to the generation that follows us. That is why I have agreed to chair the AGU 2009 Voluntary Contribution Campaign.

  11. Local NASA Scientists Discover New Species of Organism in Mars-Like Environment

    Science.gov (United States)

    2003-01-01

    Microbiologist Dr. Elena V. Pikuta, and Astrobiologist Richard Hoover culture extremophiles, microorganisms that can live in extreme environments, in the astrobiology laboratory at the National Space Science and Technology Center (NSSTC) in Huntsville, Alabama. The scientists recently discovered a new species of extremophiles, Spirochaeta Americana. The species was found in Northern California's Mono Lake, an alkaline, briny oxygen-limited lake in a closed volcanic crater that Hoover believes may offer new clues to help identify sites to research for potential life on Mars. Hoover is an astrobiologist at NASA's Marshall Space Flight Center (MSFC), and Pikuta is a microbiologist with the Center for Space Plasma and Aeronomy Research Laboratory at the University of Alabama in Huntsville. The NSSTC is a partnership with MSFC, Alabama universities, industry, research institutes, and federal agencies.

  12. Potential of Radiotelescopes for Atmospheric Line Observations: I. Observation Principles and Transmission Curves for Selected Sites

    CERN Document Server

    Schneider, Nicola; Baron, Philippe

    2009-01-01

    Existing and planned radiotelescopes working in the millimetre (mm) and sub-millimetre wavelengths range provide the possibility to be used for atmospheric line observations. To scrutinize this potential, we outline the differences and similarities in technical equipment and observing techniques between ground-based aeronomy mm-wave radiometers and radiotelescopes. Comprehensive tables summarizing the technical characteristics of existing and future (sub)-mm radiotelescopes are given. The advantages and disadvantages using radiotelescopes for atmospheric line observations are discussed. In view of the importance of exploring the sub-mm and far-infrared wavelengths range for astronomical observations and atmospheric sciences, we present model calculations of the atmospheric transmission for selected telescope sites (DOME-C/Antarctica, ALMA/Chajnantor, JCMT and CSO on Mauna Kea/Hawaii, KOSMA/Swiss Alpes) for frequencies between 0 and 2000 GHz (0 to 150 micron) and typical atmospheric conditions using the forwar...

  13. Summaries of physical research in the geosciences

    Energy Technology Data Exchange (ETDEWEB)

    1990-10-01

    The Department of Energy supports research in the geosciences in order to provide a sound foundation of fundamental knowledge in those areas of the geosciences which are germane to the Department of Energy's many missions. The Division of Engineering and Geosciences, part of the Office of Basic Energy Sciences of the Office of Energy Research, supports the Geosciences Research Program. The participants in this program include Department of Energy laboratories, industry, universities, and other governmental agencies. The summaries in this document, prepared by the investigators, briefly describe the scope of the individual programs. The Geosciences Research Program includes research in geology, petrology, geophysics, geochemistry, solar physics, solar-terrestrial relationships, aeronomy, seismology, and natural resource modeling and analysis, including their various subdivisions and interdisciplinary areas. All such research is related either directly or indirectly to the Department of Energy's long-range technological needs.

  14. Simulation of polyvinylidene fluoride detector response to hypervelocity particle impact

    International Nuclear Information System (INIS)

    Polyvinylidene fluoride (PVDF) films have been utilized as interplanetary dust detectors for many years in a variety of space environments. PVDF serves as a dust detector by producing a 'depolarization' charge upon hypervelocity impact. Previous instruments have relied on empirical calibrations to establish the relationship between the mass and velocity of the impacting dust particle and the generated charge. Here, we present a new theoretical derivation of PVDF response to non-penetrating hypervelocity particle impacts. We compare our simulation results to experimental calibration data from the Cosmic Dust Experiment on the Aeronomy of Ice in the Mesosphere satellite and the Student Dust Counter on the New Horizons mission. The simulation results agree well with the experimental data, yet suggest a modified crater diameter scaling law for non-penetrating hypervelocity impacts into PVDF.

  15. Latitudinal dependence of the variability of the micrometeor altitude distribution

    Science.gov (United States)

    Sparks, J. J.; Janches, D.

    2009-06-01

    We present a study of the diurnal behavior of the observed meteor altitude distribution at different seasons and latitudes. The meteor altitude distribution provides an indication of where the meteoric mass deposition occurs in the mesosphere and lower thermosphere (MLT). This can be utilized to model the input of metallic constituents into the MLT and accurately understand the chemistry of this region. We show that the observed altitude distributions have distinct variability at each location: at high latitudes there is a weak diurnal and strong seasonal variability while at tropical latitudes the opposite behavior is observed. We explain these results by correlating them with the astronomical and physical properties of the meteoric flux. Finally, we discussed the potential influences that these results have on the metal chemistry and aeronomy of this atmospheric region.

  16. Starguides plus a world-wide directory of organizations in astronomy and related space sciences

    CERN Document Server

    Heck, André

    2004-01-01

    StarGuides Plus represents the most comprehensive and accurately validated collection of practical data on organizations involved in astronomy, related space sciences and other related fields This invaluable reference source (and its companion volume, StarBriefs Plus) should be on the reference shelf of every library, organization or individual with any interest in these areas The coverage includes relevant universities, scientific committees, institutions, associations, societies, agencies, companies, bibliographic services, data centers, museums, dealers, distributors, funding organizations, journals, manufacturers, meteorological services, national norms & standard institutes, parent associations & societies, publishers, software producers & distributors, and so on Besides astronomy and associated space sciences, related fields such as aeronautics, aeronomy, astronautics, atmospheric sciences, chemistry, communications, computer sciences, data processing, education, electronics, engineering, en...

  17. Fukushima to receive Smith Medal

    Science.gov (United States)

    The 1990 Waldo E. Smith Medal for extraordinary service to geophysics will be given to Naoshi Fukushima, who earned an international reputation for his pioneering work in geomagnetic disturbance and ionospheric electric currents. Now retired from the University of Tokyo, Japan, Fukushima is being cited for his public service to international geophysics, and, in particular, his contributions to the International Association of Geomagnetism and Aeronomy, of which he was Secretary General from September 1975 to August 1983.The Smith Medal will be presented as part of the AGU Fall Meeting Honors Night festivities, Wednesday, December 5, in San Francisco, Calif. Three James B. Macelwane Medals, the John Adam Fleming Medal, and the Maurice Ewing Medal will also be presented (see Eos, February 20, 1990, p. 294).

  18. Big data era in meteor science

    Science.gov (United States)

    Vinković, D.; Gritsevich, M.; Srećković, V.; Pečnik, B.; Szabó, G.; Debattista, V.; Škoda, P.; Mahabal, A.; Peltoniemi, J.; Mönkölä, S.; Mickaelian, A.; Turunen, E.; Kákona, J.; Koskinen, J.; Grokhovsky, V.

    2016-01-01

    Over the last couple of decades technological advancements in observational techniques in meteor science have yielded drastic improvements in the quality, quantity and diversity of meteor data, while even more ambitious instruments are about to become operational. This empowers meteor science to boost its experimental and theoretical horizons and seek more advanced science goals. We review some of the developments that push meteor science into the big data era that requires more complex methodological approaches through interdisciplinary collaborations with other branches of physics and computer science. We argue that meteor science should become an integral part of large surveys in astronomy, aeronomy and space physics, and tackle the complexity of micro-physics of meteor plasma and its interaction with the atmosphere.

  19. International Geomagnetic Reference Field: the third generation.

    Science.gov (United States)

    Peddie, N.W.

    1982-01-01

    In August 1981 the International Association of Geomagnetism and Aeronomy revised the International Geomagnetic Reference Field (IGRF). It is the second revision since the inception of the IGRF in 1968. The revision extends the earlier series of IGRF models from 1980 to 1985, introduces a new series of definitive models for 1965-1976, and defines a provisional reference field for 1975- 1980. The revision consists of: 1) a model of the main geomagnetic field at 1980.0, not continuous with the earlier series of IGRF models together with a forecast model of the secular variation of the main field during 1980-1985; 2) definitive models of the main field at 1965.0, 1970.0, and 1975.0, with linear interpolation of the model coefficients specified for intervening dates; and 3) a provisional reference field for 1975-1980, defined as the linear interpolation of the 1975 and 1980 main-field models.-from Author

  20. Equitorial scintillations: Advances since ISEA-6

    Science.gov (United States)

    Basu, S.

    1985-01-01

    Since the last equatorial aeronomy meeting in 1980, our understanding of the morphology of equatorial scintillations has advanced greatly due to more intensive observations at the equatorial anomaly locations in the different longitude zones. The unmistakable effect of the sunspot cycle in controlling irregularity belt width and electron concentration responsible for strong scintillation in the GHz range has been demonstrated. The fact that night-time F-region dynamics is an important factor in controlling the magnitude of scintillations has been recognized by interpreting scintillation observations in the light of realistic models of total electron content at various longitudes. A hypothesis based on the alignment of the solar terminator with the geomagnetic flux tubes as an indicator of enhanced scintillation occurrence and another based on the influence of a transequatorial thermospheric neutral wind have been postulated to describe the observed longitudinal variation.

  1. Yakutsk Institute's cosmic ray research facility

    Science.gov (United States)

    Konovalov, B.

    1984-11-01

    Progress in cosmic physics research and aeronomy is reported. Geophysical observatories and stations, test ranges and other facilities spread over a vast territory of the Yakutsk Autonomous Republic and instruments onboard satellites are outlined. The ionosphere, magnetic fields and earth currents, cosmic rays and radio emissions, polar aurora and meteorological phenomena are studied. A large installation of the SHALL which investigates cosmic-ray showers is discussed. The creation of a unique complex for study of the ionosphere which will interconnect existing ionosphere stations near Yakutsk and in Zhigansk, a geospace-physics observatory in Tiksi, and a station which is to be created on Kotel'nyy Island is reported. It will be possible to discern from data received at central post how the solar wind is flowing around the Earth and what changes are produced in the ionosphere. The SHALL will be able to assess the radiation situation around the planet and to give accurate forecasts of shortwave radio conditions.

  2. Luhmann Receives 2007 John Adam Fleming Medal

    Science.gov (United States)

    Russell, Christopher T.; Luhmann, Janet G.

    2008-02-01

    This year's John Adam Fleming medalist quickly established a reputation as an innovative and productive scientist with a broad range of interests. She made early and seminal contributions to aeronomy, cosmic rays, and magnetospheric and planetary physics. She contributed importantly to the understanding of the interaction of the solar wind with the atmosphere and magnetic fields of Mercury, Venus, Earth, and Mars. She has examined the behavior of planetary rings, the interaction of interstellar neutrals with heliospheric plasmas, as well as the interaction of planetary neutrals with the heliosphere. She has led in the study of the interaction of the moon Titan with the Saturn magnetosphere, and most recently she developed a vigorous solar physics effort, leading the implementation of the IMPACT particle and field package on the twin STEREO mission, now entering its second year of successful operation.

  3. Summaries of physical research in the geosciences

    Energy Technology Data Exchange (ETDEWEB)

    1980-08-01

    The Department of Energy supports research in the geosciences in order to provide a sound underlay of fundamental knowledge in those areas of the earth, atmospheric, and solar/terrestrial sciences that relate to the Department of Energy's many missions. The Division of Engineering, Mathematical and Geosciences, which is a part of the Office of Basic Energy Sciences and comes under the Director of Energy Research, supports under its Geosciences program major Department of Energy laboratories, industry, universities and other governmental agencies. The summaries in this document, prepared by the investigators, describe the overall scope of the individual programs and details of the research performed during 1979-1980. The Geoscience program includes research in geology, petrology, geophysics, geochemistry, hydrology, solar-terrestrial relationships, aeronomy, seismology and natural resource analysis, including the various subdivisions and interdisciplinary areas. All such research is related to the Department's technological needs, either directly or indirectly.

  4. Physics of the Space Environment

    Science.gov (United States)

    Vasyliünas, Vytenis M.

    This book, one in the Cambridge Atmospheric and Space Science Series, joins a growing list of advanced-level textbooks in a field of study and research known under a variety of names: space plasma physics, solar-terrestrial or solar-planetary relations, space weather, or (the official name of the relevant AGU section) space physics and aeronomy. On the basis of graduate courses taught by the author in various departments at the University of Michigan, complete with problems and with appendices of physical constants and mathematical identities, this is indeed a textbook, systematic and severe in its approach. The book is divided into three parts, in length ratios of roughly 6:4:5. Part I, “Theoretical Description of Gases and Plasmas,” starts by writing down Maxwell's equations and the Lorentz transformation (no nonsense about any introductory material of a descriptive or historical nature) and proceeds through particle orbit theory, kinetics, and plasma physics with fluid and MHD approximations to waves, shocks, and energetic particle transport. Part II, “The Upper Atmosphere,” features chapters on the terrestrial upper atmosphere, airglow and aurora, and the ionosphere. Part III, “Sun-Earth Connection,” deals with the Sun, the solar wind, cosmic rays, and the terrestrial magnetosphere. The book thus covers, with two exceptions, just about all the topics of interest to Space Physics and Aeronomy scientists, and then some (the chapter on the Sun, for instance, briefly discusses also topics of the solar interior: thermonuclear energy generation, equilibrium structure, energy transfer, with a page or two on each). One exception reflects a strong geocentric bias: there is not one word in the main text on magnetospheres and ionospheres of other planets and their interaction with the solar wind (they are mentioned in a few problems). The other exception: the chapter on the terrestrial magnetosphere lacks a systematic exposition of the theory of

  5. Statistical and fragmentation properties of the micrometeoroid flux observed at Arecibo

    Science.gov (United States)

    Briczinski, S. J.; Mathews, J. D.; Meisel, D. D.

    2009-04-01

    The micrometeor observations performed using the 430 MHz Arecibo Observatory radar have proven to be crucial for the understanding of meteoric effects on the aeronomy of the upper atmosphere. Meteors observed during the February 2001, 2006, and 2007 campaigns have been analyzed with a fast Fourier transform periodic search algorithm that automatically and uniformly detects meteor events between altitudes of 80 and 142 km. We present a description of the new technique used to detect meteors as well as the meteoroid parameters: altitude profiles, radial speeds, and decelerations. We also note the expected correlation between the radar transmitted power and the observed meteor event rate. The large number of events has enabled us to statistically estimate the average mass density of the observed population indicating that our detected events are generally cometary (1 g/cm3) and not asteroidal (3 g/cm3) in origin. Additionally, many meteor events are observed in which the radar meteor disappears from one radar pulse to the next (i.e., in 1 ms). We interpret this as indicative of the catastrophic destruction of the meteoroid. Until destruction, these events appear to undergo only minor ablation of their volatile components over the observed trajectory. As with a major fraction of all events recorded, the meteoroids that disappear in a terminal event show linear decelerations before their abrupt disappearance. This apparently low ablative mass deposition process may play an important role in the composition (aeronomy) of the upper atmosphere, as it likely produces submicron-sized particles rather than the atom level products of ablation. First results on the altitude, speed, and mass distributions of terminal event meteoroids are given yielding some clues on the physics of the terminal event. Finally, the statistics of those events that yield no deceleration are compared statistically with those that exhibit deceleration with the conclusion that both groups are

  6. A new version of the NeQuick ionosphere electron density model

    Science.gov (United States)

    Nava, B.; Coïsson, P.; Radicella, S. M.

    2008-12-01

    NeQuick is a three-dimensional and time dependent ionospheric electron density model developed at the Aeronomy and Radiopropagation Laboratory of the Abdus Salam International Centre for Theoretical Physics (ICTP), Trieste, Italy and at the Institute for Geophysics, Astrophysics and Meteorology of the University of Graz, Austria. It is a quick-run model particularly tailored for trans-ionospheric applications that allows one to calculate the electron concentration at any given location in the ionosphere and thus the total electron content (TEC) along any ground-to-satellite ray-path by means of numerical integration. Taking advantage of the increasing amount of available data, the model formulation is continuously updated to improve NeQuick capabilities to provide representations of the ionosphere at global scales. Recently, major changes have been introduced in the model topside formulation and important modifications have also been introduced in the bottomside description. In addition, specific revisions have been applied to the computer package associated to NeQuick in order to improve its computational efficiency. It has therefore been considered appropriate to finalize all the model developments in a new version of the NeQuick. In the present work the main features of NeQuick 2 are illustrated and some results related to validation tests are reported.

  7. Radar observations of artificial E-region field-aligned irregularities

    Directory of Open Access Journals (Sweden)

    E. Nossa

    2009-07-01

    Full Text Available Artificial E region field aligned plasma density irregularities (FAIs were generated using HAARP in four different experimental modes and observed with a coherent scatter radar imager located 450 km to the southwest where it could detect field-aligned backscatter. The experiments were conducted in July of 2008, during the Polar Aeronomy and Radio Science Summer School (PARS, during quiet conditions in the daytime when the E layer was dense and absorption was modest. The echoes observed during zenith and magnetic zenith heating experiments were deflected from their nominally anticipated horizontal positions toward the midpoint position. The occurrence of hysteresis when heating with amplitude modulated pulses implied the development of the resonance instability, although the threshold for the onset of instability appeared to be higher than what has been predicted theoretically. Heating experiments involving pump frequencies slightly above and below the second electron gyroharmonic frequency produced no significant differences in the observed echoes. Finally, heating with a pump frequency slightly above the E region critical frequency appears to have produced FAIs at two distinct altitudes where the upper-hybrid resonance condition could be satisfied.

  8. Submillimeter Astronomy from the South Pole (AST/RO)

    Science.gov (United States)

    Stark, Antony A.

    2013-01-01

    The Antarctic Submillimeter Telescope and Remote Observatory (AST/RO), a 1.7 m diameter offset Gregorian telescope for astronomy and aeronomy studies at wavelengths between 200 and 2000 μm, saw first light in 1995 and operated until 2005. It was the first radio telescope to operate continuously throughout the winter on the Antarctic Plateau. It served as a site testing instrument and prototype for later instruments, as well as executing a wide variety of scientific programs that resulted in six doctoral theses and more than one hundred scientific publications. The South Pole environment is unique among observatory sites for unusually low wind speeds, low absolute humidity, and the consistent clarity of the submillimeter sky. Especially significant are the exceptionally low values of sky noise found at this site, a result of the small water vapor content of the atmosphere. Multiple submillimeter-wave and Terahertz detector systems were in operation on AST/RO, including heterodyne and bolometric arrays. AST/RO's legacy includes comprehensive submillimeter-wave site testing of the South Pole, spectroscopic studies of 492 GHz and 809 GHz neutral atomic carbon and 460 GHz and 806 GHz carbon monoxide in the Milky Way and Magellanic Clouds, and the first detection of the 1.46 THz [N II] line from a ground-based observatory.

  9. An intercomparison of airborne VOC measurements

    International Nuclear Information System (INIS)

    During the Texas Air Quality Study (TexAQS) 2000 ambient air samples were analyzed on-board the NSF/NCAR ELECTRA research aircraft by two VOC measurement techniques: 1) an in-situ gas chromatograph named TACOH (Tropospheric Airborne Chromatograph for Oxy-hydrocarbons and Hydrocarbons), operated by NOAA's Aeronomy Laboratory, and 2) a chemical ionization mass spectrometer named PTR-MS (Proton-Transfer-Reaction Mass Spectrometer) and operated by the University of Innsbruck. The sample protocols were quite different for the two methods: the TACOH system collected air samples for 15-60 sec (depending upon altitude) every 15 min, the PTR-MS system monitored selected VOCs on a time-shared basis for 2 sec respectively, once every 4-20 sec, depending upon the number of monitored species. Simultaneous measurements of acetaldehyde, isoprene, the sum of acetone and propanal, the sum of methyl vinyl ketone and methacrolein (PTR-MS does not distinguish between isobaric species) and toluene show good agreement despite being performed in the complex and highly polluted Houston air matrix. (author)

  10. Impact of the January 2012 solar proton event on polar mesospheric clouds

    Science.gov (United States)

    Bardeen, C. G.; Marsh, D. R.; Jackman, C. H.; Hervig, M. E.; Randall, C. E.

    2016-08-01

    We use data from the Aeronomy of Ice in the Mesosphere mission and simulations using the Whole Atmosphere Community Climate Model to determine the impact of the 23-30 January 2012 solar proton event (SPE) on polar mesospheric clouds (PMCs) and mesospheric water vapor. We see a small heating and loss of ice mass on 26 January that is consistent with prior results but is not statistically significant. We also find a previously unreported but statistically significant ~10% increase in ice mass and in water vapor in the sublimation area in the model that occurs in the 7 to 14 days following the start of the event. The magnitude of the response to the January 2012 SPE is small compared to other sources of variability like gravity waves and planetary waves; however, sensitivity tests suggest that with larger SPEs this delayed increase in ice mass will increase, while there is little change in the loss of ice mass early in the event. The PMC response to SPEs in models is dependent on the gravity wave parameterization, and temperature anomalies from SPEs may be useful in evaluating and tuning gravity wave parameterizations.

  11. Summaries of FY 91 geosciences research

    Energy Technology Data Exchange (ETDEWEB)

    1991-11-01

    The Department of Energy supports research in the geosciences in order to provide a sound foundation of fundamental knowledge in those areas of the geosciences which are germane to the Department of Energy's many missions. The Division of Engineering and Geosciences, part of the Office of Basic Energy Sciences of the Office of Energy Research supports the Geosciences Research Program. The participants in this program include Department of Energy laboratories, academic institutions, and other governmental agencies. Theses activities are formalized by a contract or grant between the Department of Energy and the organization performing the work, providing funds for salaries, equipment, research materials, and overhead. The summaries in this document, prepared by the investigators, describe the scope of the individual programs. The Geosciences Research Program includes research in geology, petrology, geophysics, geochemistry, solar physics, solar-terrestrial relationships, aeronomy, seismology, and natural resource modeling and analysis, including their various subdivisions and interdisciplinary areas. All such research is related either directly or indirectly to the Department of Energy's long-range technological needs. 2 tabs.

  12. Geomagnetic Workshop, Canberra

    Science.gov (United States)

    Barton, C. E.; Lilley, F. E. M.; Milligan, P. R.

    On May 14-15, 1985, 63 discerning geomagnetists flocked to Canberra to attend the Geomagnetic Workshop coorganized by the Australian Bureau of Mineral Resources (BMR) and the Research School of Earth Sciences, Australian National University (ANU). With an aurorally glowing cast that included an International Association of Geomagnetism and Aeronomy (IAGA) president, former president, and division chairman, the Oriental Magneto-Banquet (which was the center of the meeting), was assured of success. As a cunning ploy to mask the true nature of this gastronomic extravagance from the probings of income tax departments, a presentation of scientific papers on Australian geomagnetism in its global setting was arranged.The Australian region, including New Zealand, Papua New Guinea, Indonesia, and a large sector of the Antarctic, covers one eighth of the Earth's surface and historically has played an important role in the study of geomagnetism. The region contains both the south magnetic and geomagnetic poles, and two Australian Antarctic stations (Casey and Davis) are situated in the region of the south polar cusp (see Figure 1).

  13. A Review of Low Frequency Electromagnetic Wave Phenomena Related to Tropospheric-Ionospheric Coupling Mechanisms

    Science.gov (United States)

    Simoes, Fernando; Pfaff, Robert; Berthelier, Jean-Jacques; Klenzing, Jeffrey

    2012-01-01

    Investigation of coupling mechanisms between the troposphere and the ionosphere requires a multidisciplinary approach involving several branches of atmospheric sciences, from meteorology, atmospheric chemistry, and fulminology to aeronomy, plasma physics, and space weather. In this work, we review low frequency electromagnetic wave propagation in the Earth-ionosphere cavity from a troposphere-ionosphere coupling perspective. We discuss electromagnetic wave generation, propagation, and resonance phenomena, considering atmospheric, ionospheric and magnetospheric sources, from lightning and transient luminous events at low altitude to Alfven waves and particle precipitation related to solar and magnetospheric processes. We review in situ ionospheric processes as well as surface and space weather phenomena that drive troposphere-ionosphere dynamics. Effects of aerosols, water vapor distribution, thermodynamic parameters, and cloud charge separation and electrification processes on atmospheric electricity and electromagnetic waves are reviewed. We also briefly revisit ionospheric irregularities such as spread-F and explosive spread-F, sporadic-E, traveling ionospheric disturbances, Trimpi effect, and hiss and plasma turbulence. Regarding the role of the lower boundary of the cavity, we review transient surface phenomena, including seismic activity, earthquakes, volcanic processes and dust electrification. The role of surface and atmospheric gravity waves in ionospheric dynamics is also briefly addressed. We summarize analytical and numerical tools and techniques to model low frequency electromagnetic wave propagation and solving inverse problems and summarize in a final section a few challenging subjects that are important for a better understanding of tropospheric-ionospheric coupling mechanisms.

  14. A spectral line survey of Orion KL in the bands 486-492 and 541-577 GHz with the Odin satellite I. The observational data

    CERN Document Server

    Olofsson, A O H; Koning, N; Bergman, P; Bernath, P; Black, J H; Frisk, U; Geppert, W; Hasegawa, T I; Hjalmarson, A; Kwok, S; Larsson, B; Lecacheux, A; Nummelin, A; Olberg, M; Sandqvist, Aa; Wirstrom, E S; 10.1051/0004-6361:20077229

    2007-01-01

    Spectral line surveys are useful since they allow identification of new molecules and new lines in uniformly calibrated data sets. Nonetheless, large portions of the sub-millimetre spectral regime remain unexplored due to severe absorptions by H2O and O2 in the terrestrial atmosphere. The purpose of the measurements presented here is to cover wavelength regions at and around 0.55 mm -- regions largely unobservable from the ground. Using the Odin astronomy/aeronomy satellite, we performed the first spectral survey of the Orion KL molecular cloud core in the bands 486--492 and 541--576 GHz with rather uniform sensitivity (22--25 mK baseline noise). Odin's 1.1 m size telescope, equipped with four cryo-cooled tuneable mixers connected to broad band spectrometers, was used in a satellite position-switching mode. Two mixers simultaneously observed different 1.1 GHz bands using frequency steps of 0.5 GHz (25 hours each). An on-source integration time of 20 hours was achieved for most bands. The entire campaign consu...

  15. Proceedings of the IRI Task Force Activity 2001

    International Nuclear Information System (INIS)

    This ICTP Internal Report contains the list of papers presented, activity report and the write up of a number of presentations delivered during the International Reference Ionosphere (IRI) Task Force Activity 2001 which took place at the Abdus Salam ICTP during May 2001, particularly centred in the week from 21-25 May. The 2001 Task Force Activity is the eighth successful encounter of specialists organized by the URSI-Cospar IRI Working Group and the Aeronomy and Radiopropagation Laboratory of the Abdus Salam International Centre for Theoretical Physics of Trieste, Italy. This project continues the IRI Task Force Activities at the Abdus Salam International Centre for Theoretical Physics (ICTP) in Trieste, Italy. The primary focus of this activity was the development of a specification model for ionospheric variability. Such a model is high on the wish list of users of ionospheric models. Climatological models like IRI provide monthly mean values of ionospheric parameters. Understandably a satellite designer or operator needs to know not only the monthly average conditions but also the expected deviations from these mean values. The main discussions and presentations took place during the week 21-25 May. The format was similar to last year's activity with presentations and round-table discussions in the morning and follow-on work in small subgroups in front of computer terminals in the afternoon. This Proceedings contains also four papers of the previous IRI Task Force Activity which were omitted

  16. Recent Advances in Narrowband Stimulated Electromagnetic Emission NSEE Investigations at HAARP and EISCAT

    Science.gov (United States)

    Scales, Wayne

    2016-07-01

    Investigation of stimulated radiation, commonly known as Stimulated Electromagnetic Emissions (SEE), produced by the interaction of high-power, High Frequency HF radiowaves with the ionospheric plasma has been a vibrant area of research since the early 1980's. Substantial diagnostic information about ionospheric plasma characteristics, dynamics, and turbulence can be obtained from the frequency spectrum of the stimulated radiation. During the past several decades, so-called wideband SEE (WSEE) which exists in a frequency band of ±100 KHz or so of the transmit wave frequency (which is several MHz) has been investigated relatively thoroughly. Upgrades both in transmitter power and diagnostic receiver frequency sensitivity at major ionosphere interaction facilities (i.e. HAARP and EISCAT) have allowed new breakthroughs in the ability to study a plethora of processes associated with the ionospheric plasma during these active experiments. A primary advance is in observations of so-called narrowband SEE (NSEE) which exists roughly within ±1 kHz of the transmit wave frequency. NSEE investigation has opened the door for a potentially powerful tool for aeronomy investigations as well. An overview of several important new results associated with NSEE are discussed in this presentation, including observations, theory, computational modeling, as well as implications to new diagnostics of space plasma physics occurring during ionospheric interaction experiments.

  17. Paleomagnetism and rock magnetism at Liblice-A personal view from a participant

    Science.gov (United States)

    Hoffman, Ken

    The New Trends and Databases in Paleomagnetism and Rock Magnetism Conference held in Liblice, Czechoslovakia, from June 27 to July 2, 1988, was indeed a most memorable event. In ways seldom experienced at large International Association of Geomagnetism and Aeronomy (IAGA) assemblies, the quality of two-way exchange between “east” and “west” was magical. For 5 days, “home” for most of the 68 participants was the baroque Liblice Castle, a remnant of 18th century Bohemian feudalism. The setting was serene, among acres of wheat produced by the local communal farm, located some 40 km north of Prague. Beyond the physical environment, the uniqueness of the gathering resulted from the demographic makeup of the participants. With small delegations from Scandanavia and the west—just four of us from the United States—the vast majority who descended on the castle came from the Soviet Union, Czechoslovakia, and nearly every other eastern bloc neighbor. Even at IAGA in Prague just 3 years ago, where participation was more uniform, the sheer size of the assembly was to some degree an obstacle toward east-west communication and perhaps tended to promote western views only. Not so at Liblice; we were definitely on different turf!

  18. Swarm - The European Space Agency's Constellation Mission: Mapping Earth's Magnetic and Electric Fields

    Science.gov (United States)

    Floberghagen, Rune

    2016-07-01

    Launched on 22 November 2013, the three-satellite Swarm constellation is about halfway into its four-year nominal mission. Embarking identical, high accuracy and high spatial as well as temporal resolution instrumentation on all satellites, the mission has ambitious goals reaching from the deep Earth interior (the liquid outer core) all the way out to the solar-terrestrial interaction in the magnetosphere. One may safely state that the mission addresses a diverse range of science issues, and therefore acts as a true discoverer in many fields. Measurements of the magnetic field (magnitude and vector components), the electric field (through ion drift velocity, ion density, ion temperature, electron density, electron temperature and spacecraft potential), the gas density and horizontal winds as well as precise positioning are supported by a range of derived products for the magnetic field, geophysics, aeronomy and space physics communities. Indeed, Swarm is at the forefront of cross-cutting science issues that involve significant parts of the space and earth physics community. In recent data exploitation and science projects we have also seen a high number of coupling studies emerging. This contribution details the status and achievements of the mission in the field of magnetic field, electric field and geospace research. It furthermore discusses the the Agency's further plans, beyond the currently foreseen nominal end of mission in spring 2018. The role of Swarm for space weather research will also be discussed.

  19. World Digital Magnetic Anomaly Map version 2 (WDMAM v.2) - released for research and education

    Science.gov (United States)

    CHOI-Dyment, Y.; Lesur, V.; Dyment, J.; Hamoudi, M.; Thebault, E.; Catalan, M.

    2015-12-01

    The World Digital Magnetic Anomaly Map is an international initiative carried out under the auspices of the International Association of Geomagnetism and Aeronomy (IAGA) and the Commission for the Geological Map of the World (CGMW). A first version of the map has been published and distributed eight years ago (WDMAM v1; Korhonen et al., 2007). We have produced a candidate which has been accepted as the second version of this map (WDMAM v2) at the International Union of Geophysics and Geodesy in Prag, in June 2015. On land, we adopted an alternative approach avoiding any unnecessary processing on existing aeromagnetic compilations. When available, we used the original aeromagnetic data. As a result the final compilation remains an acceptable representation of the national and international data grids. Over oceanic areas the marine data have been extended. In areas of insufficient data coverage, a model has been computed based on a modified digital grid of the oceanic lithosphere age, considering plate motions in the determination of magnetization vector directions. This model has been further adjusted to the available data, resulting in a better representation of the anomalies. The final grid will be periodically upgraded. Version 2.0 has been released and is available at wdmam.org to support both research and education projects. Colleagues willing to contribute data for future releases (and become a co-author of the map) should contact any of the authors or Jerome Dyment (chair of the WDMAM Task Force) at jdy@ipgp.fr .

  20. Physico-chemistry of ices in space: from Earth to the ISS to the solar system and beyond

    Science.gov (United States)

    Blum, J.; Ehrenfreund, P.; Fraser, H.; Garcia Ruiz, J.; Hadamcik, E.; Levasseur-Regourd, A.; Sarkissan, A.; Price, S.; Prodi, F.; Williams, D.

    Ices are observed throughout the universe: in other galaxies, star-forming regions, in the Interstellar Medium (ISM) and in protoplanetary disks. Molecular ices are also widespread in our Solar System: they cover the poles of terrestrial planets (e.g. Earth, Mars), the surfaces of planets, moons, and smaller bodies in the outer solar system (e.g. Europa, comets), and exist in planetary atmospheres, including our own. This ESA-funded Topical Team was formed in response to the International Announcement of Opportunity 2000, in Basic and Applied Physical Sciences, to investigate future research directions in ice physics and chemistry in support of astronomy, aeronomy and atmospheric sciences. These investigations have included laboratory based requirements, experiments under micro- or reduced gravity, and exploration of our local solar system. Many experiments that evaluate the physical and chemical properties of the ice under realistic atmospheric / astronomical conditions require small particles or clouds. In both instances ice studies under microgravity conditions offer significant advantages. By studying the surface and bulk morphology of molecular ices in microgravity over a range of pressure and temperature conditions, we will be able to emulate ice morphologies in other regions of our universe. This will also include the characterization of icy aerosol particles which play an important role in Earth's climate system and in atmospheric chemistry. In this paper we will present the team's key findings, describing the research that is possible with existing laboratory and ISS facilities, as well as planned and future ISS facilities and space-based missions.

  1. The Polar Cap (PC) index. A critical review of methods and a new approach.

    Science.gov (United States)

    Stauning, Peter

    2013-04-01

    The Polar Cap (PC) index introduced by Troshichev and Andrezen (1985) is derived from polar magnetic variations and is mainly a measure of the intensity of the transpolar ionospheric currents. These currents relate to the polar cap antisunward ionospheric plasma convection driven by the dawn-dusk electric field, which in turn is generated by the interaction of the solar wind with the Earth's magnetosphere. Coefficients to calculate PCN and PCS index values from polar magnetic variations recorded at Thule and Vostok, respectively, have been derived by several different procedures in the past. Approval of a final PC index procedure is pending at the International Association for Geomagnetism and Aeronomy (IAGA) for a decision possibly at the General Assembly in 2013. The presentation discusses the principal differences between the various PC index procedures and provides comparisons between coefficient and index values derived using the different procedures. It will be demonstrated that depending on the procedure, PC index values derived in the past, and used in many publications, may differ substantially although the same basic geomagnetic data were used. Finally, a new approach to define a unified PC index procedure, built from the best elements of the three different current versions, is outlined.

  2. A critical note on the IAGA-endorsed Polar Cap index procedure: effects of solar wind sector structure and reverse polar convection

    Science.gov (United States)

    Stauning, P.

    2015-11-01

    The International Association of Geomagnetism and Aeronomy (IAGA) has recently endorsed a new Polar Cap (PC) index version to supersede the previous seven different versions of the PCN (North) index and the five different PCS (South) index versions. However, the new PC index has some adverse features which should be known and taken into account by users of the index. It uses in its derivation procedure an "effective" quiet day level (QDC) composed of a "basic" QDC and an added solar wind sector term related to the azimuthal component (By) of the interplanetary magnetic field (IMF). The added IMF By-related terms may introduce unjustified contributions to the PC index of more than 2 index units (mV m-1). Furthermore, cases of reverse convection during strong northward IMF Bz (NBZ) conditions included in the database for calculation of index coefficients can cause unjustified index enhancements of 0.5-1 mV m-1 during calm conditions, reduction of index values by more than 20 % during disturbed conditions, and inconsistencies between index coefficients and index values for the northern and southern polar caps. The aim here is to specify these adverse features and quantify their effects, and to suggest alternative steps for future modifications of the index procedure.

  3. A critical note on the IAGA-endorsed Polar Cap index procedure. Effects of solar wind sector structure and reverse polar convection

    Energy Technology Data Exchange (ETDEWEB)

    Stauning, P. [Danish Meteorological Institute, Copenhagen (Denmark)

    2015-07-01

    The International Association of Geomagnetism and Aeronomy (IAGA) has recently endorsed a new Polar Cap (PC) index version to supersede the previous seven different versions of the PCN (North) index and the five different PCS (South) index versions. However, the new PC index has some adverse features which should be known and taken into account by users of the index. It uses in its derivation procedure an ''effective'' quiet day level (QDC) composed of a ''basic'' QDC and an added solar wind sector term related to the azimuthal component (B{sub y}) of the interplanetary magnetic field (IMF). The added IMF B{sub y}-related terms may introduce unjustified contributions to the PC index of more than 2 index units (mV m{sup -1}). Furthermore, cases of reverse convection during strong northward IMF B{sub z} (NBZ) conditions included in the database for calculation of index coefficients can cause unjustified index enhancements of 0.5-1 mV m{sup -1} during calm conditions, reduction of index values by more than 20% during disturbed conditions, and inconsistencies between index coefficients and index values for the northern and southern polar caps. The aim here is to specify these adverse features and quantify their effects, and to suggest alternative steps for future modifications of the index procedure.

  4. A statistical study of meteoroid fragmentation and differential ablation using the Resolute Bay Incoherent Scatter Radar

    Science.gov (United States)

    Malhotra, Akshay; Mathews, John D.

    2011-04-01

    There has been much interest in the meteor physics community recently regarding the detailed processes by which the meteoroid mass flux arrives in the upper atmosphere. Of particular interest are the relative roles of simple ablation, differential ablation, and fragmentation in interpretation of the meteor events observed by the high-power large-aperture (HPLA) radars. An understanding of the relative roles of these mechanisms is necessary to determine whether the considerable meteor mass flux arriving in the upper atmosphere arrives mostly in nanometer dust/smoke (via fragmentation) or atomic form (via ablation), which in turn has important consequences in understanding not only the aeronomy of the region but also the formation and evolution of various upper atmospheric phenomenon such as Polar Mesospheric Summer Echoes. Using meteor observations from the newly operational Resolute Bay Incoherent Scatter Radar (RISR), we present the first statistical study showing the relative contribution of these mechanisms. We find that RISR head echoes exhibited ˜48% fragmentation, ˜32% simple ablation, and ˜20% differential ablation. We also report existence of compound meteor events exhibiting signatures of more than one mass loss mechanism. These results emphasize that the processes by which the meteoroid mass is deposited into the upper atmosphere are complex and involve all three mechanisms described here. This conclusion is unlike the previously reported results that stress the importance of one or the other of these mechanisms. These results will also contribute in improving current meteoroid disintegration/ablation models.

  5. 1991 Fall Meeting Report

    Science.gov (United States)

    Chapman, David S.

    The AGU 1991 Fall Meeting, held in San Francisco December 9-13, was the largest national AGU meeting ever held. Meeting participation continued the steady growth trend set throughout the previous decade. A total of 4,037 papers and posters were presented, and by Friday noon of the meeting over 5,500 members had registered.Several special events were scheduled to inform and engage members on societal and programmatic aspects of our science. AGU's Committee on Education and Human Resources sponsored an open forum that addressed opportunities and problems associated with dual-career couples. A discussion of NASA's strategic plan by Berrien Moore and Joseph Alexander drew a large audience, and a special session on societal aspects of the Mt. Pinatubo eruption drew an overflow crowd. Two special lectures— “Plumes, Plates, and Deep Earth Structure” by Don L. Anderson and “New Frontiers in Aeronomy: Effects of Global Atmospheric Change” by P. M. Banks-also drew overflow crowds.

  6. Support to Aviation Control Service (SACS: an online service for near real-time satellite monitoring of volcanic plumes

    Directory of Open Access Journals (Sweden)

    H. Brenot

    2013-10-01

    Full Text Available Volcanic eruptions emit plumes of ash and gases in the atmosphere, potentially at very high altitudes. Ash rich plumes are hazardous for airplanes as ash is very abrasive and easily melts inside their engines. With more than 50 active volcanoes per year and the ever increasing number of commercial flights, the safety of airplanes is a real concern. Satellite measurements are ideal for monitoring global volcanic activity and, in combination with atmospheric dispersion models, to track and forecast volcanic plumes. Here we present the Support to Aviation Control Service (SACS, http://sacs.aeronomie.be, which is a free online service initiated by ESA for the near real-time (NRT satellite monitoring of volcanic plumes of SO2 and ash. It combines data from two UV-visible (OMI, GOME-2 and two infrared (AIRS, IASI spectrometers. This new multi-sensor warning system of volcanic plumes, running since April 2012, is based on the detection of SO2 and is optimised to avoid false alerts while at the same time limiting the number of notifications in case of large plumes. The system shows successful results with 95% of our notifications corresponding to true volcanic activity.

  7. Energy Flows in the Jupiter-Io System

    CERN Document Server

    Liu, Siming

    2016-01-01

    With the laws of mass conservation, momentum conservation and energy conservation, incorporating the processes of neutral gas ionization and ion diffusion, we develop a self-consistent model for the bright ribbon --- the most prominent feature in Io's plasma torus. The model parameters are well constrained by earlier {\\it in situ} observations with the Galileo and Voyager spacescrafts. Our model calculation indicates that the total power dissipated inside the torus is 3.6 times bigger than the total power transported to Jovian ionosphere via Birkeland current. The power dissipation inside the torus is relatively uniform. Most of the power transportation associated with the Birkeland current, however, is localized near the flux tube of Io. With a height-intergrated conductivity of 0.15$\\,$mho in Jovian ionosphere, consistent with earlier aeronomy models, the model gives a reasonable fit to the recent observations of the FUV Io tail on Jupiter. Extra mass loading near Io is required in the model. This excess of...

  8. Ground Testing and Flight Demonstration of Charge Management of Insulated Test Masses Using UV LED Electron Photoemission

    CERN Document Server

    Saraf, Shailendhar; Balakrishnan, Karthik; Lui, Chin Yang; Soulage, Michael; Faied, Dohy; Hanson, John; Ling, Kuok; Jaroux, Belgacem; AlRashed, Abdullah; Nassban, Badr Al; Suwaidan, Badr Al; Harbi, Mohammed Al; Salamah, Badr Bin; Othman, Mohammed Bin; Qasim, Bandar Bin; DeBra, Daniel; Byer, Robert

    2016-01-01

    The UV LED mission demonstrates the precise control of the potential of electrically isolated test masses that is essential for the operation of space accelerometers and drag free sensors. Accelerometers and drag free sensors were and remain at the core of geodesy, aeronomy, and precision navigation missions as well as gravitational science experiments and gravitational wave observatories. Charge management using photoelectrons generated by the 254 nm UV line of Hg was first demonstrated on Gravity Probe B and is presently part of the LISA Pathfinder technology demonstration. The UV LED mission and prior ground testing demonstrates that AlGaN UV LEDs operating at 255 nm are superior to Mercury vapor lamps because of their smaller size, lower draw, higher dynamic range, and higher control authority. We show flight data from a small satellite mission on a Saudi Satellite that demonstrates AC charge control (UV LEDs and bias are AC modulated with adjustable relative phase) between a spherical test mass and its h...

  9. Contribution of the Ebro Observatory team to the IRI climatological modeling: A Review.

    Science.gov (United States)

    Altadill, David; Blanch, Estefania; Miquel Torta, J.

    During the recent years, the Geomagnetism and Aeronomy group of the Ebre Observatory has been working to improve the climatological prediction of some ionospheric key parameters. To do that, we have taken advantage of the increasing number of ionospheric stations providing data and sharing it through the Digital Ionospheric Data Base (DIDB). We have used the Spherical Harmonic analysis as analytical technique for globally modeling those parameters during quiet conditions. Models for bottom-side B0 and B1 parameters of IRI, for density peak height (hmF2) and for equivalent scale height (Hm) have been developed. Each SH model has been parameterized according to the time-space pattern of respectively ionospheric parameter and has been bounded to the solar activity. It has been proved that these empirical models improve, in average, the prediction of B0, B1 and hmF2 by 40%, 20% and 10% respectively with respect to previous IRI versions (hmF2 is improved by more than 30% at high and low latitudes). Due to these good results and to the analytical formulation, IRI has adopted the SH empirical models for B0 and B1 as an option in the current version (IRI 2012) and has proposed the SH model for hmF2 to be included into next releases. The analytical model for Hm could be useful to estimate information for the topside profile formulation.

  10. History of EISCAT - Part 4: On the German contribution to the early years of EISCAT

    Science.gov (United States)

    Haerendel, Gerhard

    2016-07-01

    The decision of the Max Planck Society (MPG) to get involved in the establishment of an incoherent scatter radar in northern Europe was intimately linked to the future of the Max Planck Institute for Aeronomy (MPAe) in Katlenburg-Lindau. Delegates of the MPG played an important role in defining the rules for participation in EISCAT during the period from 1973 to 1975. The "technical" period from 1976 to 1981 was mainly devoted to the development of the UHF transmitter and the klystrons. The latter encountered great difficulties, causing substantial delays. During the same period the ionospheric heating facility was established by MPAe at Ramfjordmoen, Norway. The period following the inauguration in August 1981 saw a great number of changes in the leading personnel. In this context much attention had to be given to taxation rules. Besides continuing hardware problems with the UHF radar, severe problems arose with design and manufacturing of the VHF klystrons, requiring changes of the contractor. However, by fall of 1983 the UHF radar was able to reach the intended operational level. In 1984 important steps were made for archiving and for proper exploitation of the EISCAT data.

  11. Future Titan Missions

    Science.gov (United States)

    Waite, J. H.; Coustenis, A.; Lorenz, R.; Lunine, J.; Stofan, E.

    2012-04-01

    New discoveries about Titan from the Cassini-Huygens mission have led to a broad range of mission class studies for future missions, ranging from NASA Discovery class to International Flagship class. Three consistent science themes emerge and serve as a framework for discussing the various mission concepts: Goal A: Explore Titan, an Earth-Like System - How does Titan function as a system? How are the similarities and differences with Earth, and other solar system bodies, a result of the interplay of the geology, hydrology, meteorology, and aeronomy present in the Titan system?; Goal B: Examine Titan’s Organic Inventory—A Path to Prebiological Molecules - What is the complexity of Titan’s organic chemistry in the atmosphere, within its lakes, on its surface, and in its putative subsurface water ocean and how does this inventory differ from known abiotic organic material in meteorites and therefore contribute to our understanding of the origin of life in the Solar System?; and Goal C: Explore Enceladus and Saturn’s magnetosphere—clues to Titan’s origin and evolution - What is the exchange of energy and material with the Saturn magnetosphere and solar wind? What is the source of geysers on Enceladus? Does complex chemistry occur in the geyser source? Within this scientific framework the presentation will overview the Titan Explorer, Titan AND Enceladus Mission, Titan Saturn System Mission, Titan Mare Explorer, and Titan Submersible. Future timelines and plans will be discussed.

  12. Laboratory Studies of Vibrational Relaxation: Important Insights for Mesospheric OH

    Science.gov (United States)

    Kalogerakis, Konstantinos S.; Matsiev, Daniel

    2016-04-01

    The hydroxyl radical has a key role in the chemistry and energetics of the Earth's middle atmosphere. A detailed knowledge of the rate constants and relevant pathways for OH(high v) vibrational relaxation by atomic and molecular oxygen and their temperature dependence is absolutely critical for understanding mesospheric OH and extracting reliable chemical heating rates from atmospheric observations. We have developed laser-based experimental approaches to study the complex collisional energy transfer processes involving the OH radical and other relevant atmospheric species. Previous work in our laboratory indicated that the total removal rate constant for OH(v = 9) + O at room temperature is more than one order of magnitude larger than that for removal by O2. Thus, O atoms are expected to significantly influence the intensity and vibrational distribution extracted from the Meinel OH(v) emissions. We will report our most recent laboratory experiments that corroborate the aforementioned result for OH(v = 9) + O and provide important new insights on the mechanistic pathways involved. We will also highlight relevant atmospheric implications, including warranted revisions of current mesospheric OH models. Research supported by SRI International Internal R&D and NSF Aeronomy grant AGS-1441896. Previously supported by NASA Geospace Science grant NNX12AD09G.

  13. Observations of fast magnetospheric echoes of artificially injected electrons above an auroral arc

    International Nuclear Information System (INIS)

    Electron beam experiments using rocket-borne instrumentation have confirmed earlier observations of fast magnetospheric echoes of artificially injected energetic electrons. These experiments were jointly carried out by the University of Minnesota, the National Research Council of Canada and the Max-Planck-Institut fuer Aeronomie. A total of 234 echoes have been observed in a pitch angle range from 00 to 1100 at energies of 1.87 and 3.90 keV. Out of this number, 95 echoes could unambiguously be identified with known accelerator operations at 2, 4 or 8 keV energy and highest current levels resulting in the determination of transit times of typically 400 ms. In most cases, when echoes were present in both energy channels, the higher energy electrons led the lower energy ones by approximately 50 ms. No echoes have been found in the 7.9 keV-detector channels. Adiabatic theory applied to these observations yields a reflection height of 3000 to 4000 km. The injection process is briefly discussed as the strong beam-plasma interaction that occurred near the electron accelerator appears to be instrumental in generating the source of heated electrons required for successful echo detection. Two consequences of this interaction, namely, strong energy and pitch angle diffusion and electron acceleration are illustrated with several examples. (orig.)

  14. Determination of water vapor and ozone profiles in the middle atmosphere by microwave-spectroscopy. Bestimmung von Wasserdampf- und Ozonprofilen in der mittleren Atmosphaere durch Millimeterwellenspektroskopie

    Energy Technology Data Exchange (ETDEWEB)

    Puliafito, S.E.

    1989-10-17

    This work was performed at the Max-Planck-Institut fuer Aeronomie (F.R.G.) and treats the following points: 1. Satellite borne microwave radiometry. Principles for a real-time evaluation of the MAS-Limb-Sounding measurements. (MAS: Millimeter Wave Atmospheric Sounder from Space Shuttle as part of the NASA ATLAS Missions, 1991-1997). (a) Deconvolution of the 60 GHz-antenna. (b) Test of different inversion proceedings. A detailed study of the boundary conditions and 'error influence' as well as a discussion of the radiometer specifications. (c) Near real time inversion of microwave spectral lines of the Earth atmosphere. i. The possibility of a (near) real time evaluation (retrieval of the profiles of the atmospheric components) was proved for the first time with a space proof microprocessor. ii. Data reduction of about a factor > 10{sup 3} in comparison with other methods. 2. Airborne and ground based microwave radiometry. (a) Study of the possibilities of ground- and aircraft based measurements for validation and cross calibration of the satellite measurements. (b) Study of the possibilities of ground based radiometric measurements of water vapour in the Artic or Antartica. Precise boundary conditions were given for the first time in order to perform ground based millimeter radiometric measurements in these areas. (orig.).

  15. 近地空间无线电信标卫星研究使命

    Institute of Scientific and Technical Information of China (English)

    黄天锡

    1991-01-01

    @@ 第10届国际信标卫星学术讨论会(International Beacon Satellite Symposium,IBSS)于1990年3月27日至30日在阿根廷杜库曼市(Tucuman)召开.21日至27日在同一地点召开第8届国际赤道高空物理学术讨论会(International Symposium on Equatorial Aeronomy,ISEA).会议由奥地利格拉兹大学气象与地球物理研究所R.Leitinger教授任主席,美国空军地球物理实验室J.A.Klobuchar博士和印度新德里国家物理实验室T.R.Tyagi博士任副主席,并由杜库曼大学电离层实验室主任J.R.Manzano教授主持会议.笔者应邀出席会议,宣读4篇学术论文并作重点发言.

  16. Observations of HF backscatter decay rates from HAARP generated FAI

    Science.gov (United States)

    Bristow, William; Hysell, David

    2016-07-01

    Suitable experiments at the High-frequency Active Auroral Research Program (HAARP) facilities in Gakona, Alaska, create a region of ionospheric Field-Aligned Irregularities (FAI) that produces strong radar backscatter observed by the SuperDARN radar on Kodiak Island, Alaska. Creation of FAI in HF ionospheric modification experiments has been studied by a number of authors who have developed a rich theoretical background. The decay of the irregularities, however, has not been so widely studied yet it has the potential for providing estimates of the parameters of natural irregularity diffusion, which are difficult measure by other means. Hysell, et al. [1996] demonstrated using the decay of radar scatter above the Sura heating facility to estimate irregularity diffusion. A large database of radar backscatter from HAARP generated FAI has been collected over the years. Experiments often cycled the heater power on and off in a way that allowed estimates of the FAI decay rate. The database has been examined to extract decay time estimates and diffusion rates over a range of ionospheric conditions. This presentation will summarize the database and the estimated diffusion rates, and will discuss the potential for targeted experiments for aeronomy measurements. Hysell, D. L., M. C. Kelley, Y. M. Yampolski, V. S. Beley, A. V. Koloskov, P. V. Ponomarenko, and O. F. Tyrnov, HF radar observations of decaying artificial field aligned irregularities, J. Geophys. Res. , 101, 26,981, 1996.

  17. Automated UHF radar observations of meteors with aeronomic applications

    Science.gov (United States)

    Briczinski, Stanley J., Jr.

    The micrometeor observations performed using the 430 MHz Arecibo Observatory radar have been crucial for the understanding of meteoric effects on the aeronomy of the upper atmosphere. Previous techniques using the Arecibo radar required manual confirmation of each event, followed by direct measurements of the parameters (i.e. altitudes, velocities and decelerations). A new periodic FFT searching algorithm, the meteor return signal detector (MRSD) has been developed and implemented, replacing previous (labor-intensive) visual verification. The MRSD shows an improvement over traditional searching routines by increasing the event detection rate by as much as 30% as well as significantly reducing the required analysis time. The new technique used to detect meteors as well as the measured parameters obtained from this method are presented. The meteor parameters obtained from the MRSD are presented. Mass distributions are obtained from momentum considerations. Previous mass distributions have assumed a constant meteoroid mass density of 3 gm/cm3. Using statistical interpretations of the parameters obtained from the MRSD, the meteoroid mass density has been revised to a constant mass density of 1 gm/cm 3. This new mass result represents the first analysis and revision of the meteoroid mass since large aperture radars began observing meteors in the early 1990s. In some cases meteors are observed that appear to catastrophically destruct within the beam. These meteors appear to undergo minor ablation of their volatile components before annihilation---the terminal event---that occurs in under 1 ms. As with essentially all observed meteoroids, the meteoroids that disappear in a terminal event appear to experience linear decelerations before their abrupt disappearance. This non-ablative mass deposition process may play an important role in the composition of the upper atmosphere as it apparently produces sub-micron-sized particles. The first statistical analyses of the terminal

  18. Solar UV Irradiances and Associated Issues for the Atmosphere and Ionosphere

    Science.gov (United States)

    Tobiska, W.

    Several new solar proxies have been developed in the past year as the beginning of a second generation solar UV modeling and forecasting capability. These proxies help characterize the energy input into operational space physics models that provide information content on the neutral thermosphere and ionosphere. Between 1999-2000, a full solar spectrum was developed (SOLAR2000) for use in numerical atmospheric and ionospheric models relevant to climatological studies and the E10.7 index was produced for empirical thermospheric and ionospheric model applications. In 20012002, new proxies have been derived including a sunspot number, Rsn, for use by operational HF radio ray-trace algorithms and the Qeuv thermospheric heating rate for use by the aeronomy community to compare airglow-derived versus solar-derived upper atmosphere heating. The Peuv heat production term has also been developed as an index for comparing solar heating to joule heating on a global scale. The S(t) index is the integrated solar spectrum used for solar radiation pressure calculations related to spacecraft attitude control. Finally, the Tinf is the exospheric temperature that is provided for long-term climate change studies. Second generation modeling and forecasting is in development and includes higher cadence solar input information beyond daily flux values where solar flare characterization will soon become reality. The second generation forecasting is also incorporating improved algorithms ranging from wavelet transforms to solar dynamo theory in order to specify solar variability on seven time scales from nowcast and 72-hour forecast to 5 solar cycle estimation. These new proxies are derivatives of the SOLAR2000 model whose solar irradiance specification is compliant with the developing ISO draft standard WD 21348 for Determining Solar Irradiances.

  19. Mirror Coronograph for Argentina (MICA). Primera Luz

    Science.gov (United States)

    Stenborg, G.; Epple, A.; Schwenn, R.; Francile, C.; Rovira, M.

    En Julio de 1997 se terminó con la primera parte de la instalación del ``Coronógrafo de Espejo para la Argentina'' en la estación de altura Carlos U. Cesco (El Leoncito), gracias al esfuerzo de la gente del Max Planck Institut für Aeronomie (Alemania), del OAFA y del IAFE. Dicho coronógrafo forma parte de un programa de ciencia bilateral entre Alemania y Argentina. El propósito del mismo, en conjunción con otros telescopios solares y terrestres, es contribuir a un mejor entendimiento de cuestiones fundamentales de la física solar. Para ello, ya está observando la corona de emisión en el verde (Fe XIV), rojo (Fe X) y Hα entre 1.05 y 2 radios solares aproximadamente. El diseño del instrumento, el cual fuera ya presentado en esta misma reunión en La Plata en 1996, es esencialmente similar al del telescopio LASCO-C1 a bordo del Solar Heliospheric Observatory (SOHO). La adquisición de datos se realiza con un CCD de 1280x1024 pixels, codificando en 12 bits, pudiendo ser el mismo operado en forma remota. En esta reunión presentaremos algunas de las observaciones realizadas durante la puesta a punto del instrumento en el período julio-setiembre de 1997. Asimismo expondremos cómo y por qué sus resultados complementarán a los de su par en el espacio.

  20. Detection of Ionospheric Alfven Resonator Signatures Onboard C/NOFS: Implications for IRI Modeling

    Science.gov (United States)

    Simoes, F.; Klenzing, J.; Ivanov, S.; Pfaff, R.; Rowland, D.; Bilitza, D.

    2011-01-01

    The 2008-2009 long-lasting solar minimum activity has been the one of its kind since the dawn of space age, offering exceptional conditions for investigating space weather in the near-Earth environment. First ever detection of Ionospheric Alfven Resonator (IAR) signatures in orbit offers new means for investigating ionospheric electrodynamics, namely MHD (MagnetoHydroDynamics) wave propagation, aeronomy processes, ionospheric dynamics, and Sun-Earth connection mechanisms at a local scale. Local and global plasma density heterogeneities in the ionosphere and magnetosphere allow for formation of waveguides and resonators where magnetosonic and shear Alfven waves propagate. The ionospheric magnetosonic waveguide results from complete magnetosonic wave reflection about the ionospheric F-region peak, where the Alfven index of refraction presents a maximum. MHD waves can also be partially trapped in the vertical direction between the lower boundary of the ionosphere and the magnetosphere, a resonance mechanism known as IAR. In this work we present C/NOFS (Communications/Navigation Outage Forecasting System) Extremely Low Frequency (ELF) electric field measurements related to IAR signatures, discuss the resonance and wave propagation mechanisms in the ionosphere, and address the electromagnetic inverse problem from which electron/ion distributions can be derived. These peculiar IAR electric field measurements provide new, complementary methodologies for inferring ionospheric electron and ion density profiles, and also contribute for the investigation of ionosphere dynamics and space weather monitoring. Specifically, IAR spectral signatures measured by C/NOFS contribute for improving the International Reference Ionosphere (IRI) model, namely electron density and ion composition.

  1. New SMILES retrievals of ozone in the mesosphere and lower thermosphere region

    Science.gov (United States)

    Kuribayashi, Kouta; Kasai, Yasuko; Orsolini, Yvan; Limpasuvan, Varavut

    2016-07-01

    Ozone in mesosphere and lower thermosphere (MLT) region has been observed from space since three decades. We examine ozone in MLT region using observations from the Superconducting Submillimeter-Wave Limb-Emission Sounder (SMILES) on the Japanese Experiment Module (JEM) of the International Space Station (ISS) between 12 October 2009 and 21 April 2010. We develop a new retrieval to improve upon previous ozone products, especially in the ozone secondary layer. One of the improvements in our new SMILES NICT level 2 product version 3.1.0 is that the profiles of the background atmosphere (altitude, pressure, and temperature) were calculated based on the global model GAIA (Ground-to-topside model of Atmosphere and Ionosphere for Aeronomy) to ensure the internal consistency of these profiles. We assess the quality of the new SMILES NICT Level2 product version 3.1.0 in the MLT region, by comparing with various satellite observations (such as SABER, GOMOS) and model calculations performed using the same background atmosphere as calculated from GAIA at the each observation point. This is to avoid that differences of ozone amount in the same air mass being caused by the use of different atmospheric conditions for calculation of volume mixing ratio from ozone density. We examine the differences caused by the vertical resolution, as well as random errors and systematic errors. The new SMILES ozone product shows good agreement with observations from other satellites in the MLT region. It sheds some light on the seasonal evolution of ozone at low latitudes, as influenced by tides.

  2. New astronomy with the Odin Satellite

    Science.gov (United States)

    Hjalmarson, A.

    On 20 February 2001 the Odin satellite - a new observatory for sub-millimetre wave spectroscopy - was launched from Svobodny in far-eastern Russia. The Odin project is a shared (50/50%) astronomy/aeronomy mission support ed by space agencies and scientists in Canada, Finland, France and Sweden. The satellite has been developed and is operated by the Swedish Space Corporation. The astronomy part of the mission is focussed on observations of line emission from interstellar H2O and O2. Odin houses a high-precision 1.1m diameter offset Gregorian telescope equipped with a very flexible cryogenic submm/mm receiver package. The frequency range 541-581 GHz is covered by three tuneable Schottky mixers and a fourth Schottky mixer covers the band 486-504 GHz.A 119 GHz fix-tuned HEMT preamplifier has been installed to allow very sensitive searches for interstellar O2. All receivers are operated in single-sideband mode. Any combination of four, three, or two receivers (depending upon the available power and mode of operation) can be used in combination with two auto-correlation spectrometers (bandwidth range: 100-800 MHz; resolution range: 0.125 -1 MHz) and an acousto-optical spectrometer, AOS (bandwidth: 1000 MHz; resolution 1 MHz). The Odin antenna beam-widths are about 2' and 9' at 557 and 119 GHz. For comparison, the SWAS (previous talk, by G. Melnick) antenna beam size is 3.3' x 4.5' at 557 GHz. In this talk I will focus on new Odin astronomy results where the higher angular resolution, higher frequency resolution, larger spectrometer bandwidth, higher sensitivity, or tuning capability (compared to SWAS) are important. Information on the Odin project can be found on the Odin web-page of the Swedish National Space Board (http://www.snsb.se/Odin/Odin.html).

  3. Persistence of upper stratospheric wintertime tracer variability into the Arctic spring and summer

    Science.gov (United States)

    Siskind, David E.; Nedoluha, Gerald E.; Sassi, Fabrizio; Rong, Pingping; Bailey, Scott M.; Hervig, Mark E.; Randall, Cora E.

    2016-06-01

    Using data from the Aeronomy of Ice in the Mesosphere (AIM) and Aura satellites, we have categorized the interannual variability of winter- and springtime upper stratospheric methane (CH4). We further show the effects of this variability on the chemistry of the upper stratosphere throughout the following summer. Years with strong wintertime mesospheric descent followed by dynamically quiet springs, such as 2009, lead to the lowest summertime CH4. Years with relatively weak wintertime descent, but strong springtime planetary wave activity, such as 2011, have the highest summertime CH4. By sampling the Aura Microwave Limb Sounder (MLS) according to the occultation pattern of the AIM Solar Occultation for Ice Experiment (SOFIE), we show that summertime upper stratospheric chlorine monoxide (ClO) almost perfectly anticorrelates with the CH4. This is consistent with the reaction of atomic chlorine with CH4 to form the reservoir species, hydrochloric acid (HCl). The summertime ClO for years with strong, uninterrupted mesospheric descent is about 50 % greater than in years with strong horizontal transport and mixing of high CH4 air from lower latitudes. Small, but persistent effects on ozone are also seen such that between 1 and 2 hPa, ozone is about 4-5 % higher in summer for the years with the highest CH4 relative to the lowest. This is consistent with the role of the chlorine catalytic cycle on ozone. These dependencies may offer a means to monitor dynamical effects on the high-latitude upper stratosphere using summertime ClO measurements as a proxy. Additionally, these chlorine-controlled ozone decreases, which are seen to maximize after years with strong uninterrupted wintertime descent, represent a new mechanism by which mesospheric descent can affect polar ozone. Finally, given that the effects on ozone appear to persist much of the rest of the year, the consideration of winter/spring dynamical variability may also be relevant in studies of ozone trends.

  4. The double electrostatic ion ring experiment: A unique cryogenic electrostatic storage ring for merged ion-beams studies

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, R. D.; Schmidt, H. T.; Andler, G.; Bjoerkhage, M.; Blom, M.; Braennholm, L.; Baeckstroem, E.; Danared, H.; Das, S.; Haag, N.; Hallden, P.; Hellberg, F.; Holm, A. I. S.; Johansson, H. A. B.; Kaellberg, A.; Kaellersjoe, G.; Larsson, M.; Leontein, S.; Liljeby, L.; Loefgren, P. [Department of Physics, Stockholm University, SE-106 91 Stockholm (Sweden); and others

    2011-06-15

    We describe the design of a novel type of storage device currently under construction at Stockholm University, Sweden, using purely electrostatic focussing and deflection elements, in which ion beams of opposite charges are confined under extreme high vacuum cryogenic conditions in separate ''rings'' and merged over a common straight section. The construction of this double electrostatic ion ring experiment uniquely allows for studies of interactions between cations and anions at low and well-defined internal temperatures and centre-of-mass collision energies down to about 10 K and 10 meV, respectively. Position sensitive multi-hit detector systems have been extensively tested and proven to work in cryogenic environments and these will be used to measure correlations between reaction products in, for example, electron-transfer processes. The technical advantages of using purely electrostatic ion storage devices over magnetic ones are many, but the most relevant are: electrostatic elements which are more compact and easier to construct; remanent fields, hysteresis, and eddy-currents, which are of concern in magnetic devices, are no longer relevant; and electrical fields required to control the orbit of the ions are not only much easier to create and control than the corresponding magnetic fields, they also set no upper mass limit on the ions that can be stored. These technical differences are a boon to new areas of fundamental experimental research, not only in atomic and molecular physics but also in the boundaries of these fields with chemistry and biology. For examples, studies of interactions with internally cold molecular ions will be particular useful for applications in astrophysics, while studies of solvated ionic clusters will be of relevance to aeronomy and biology.

  5. The SPICAV-SOIR instrument probing the atmosphere of Venus: an overview

    Science.gov (United States)

    Trompet, Loïc; Mahieux, Arnaud; Wilquet, Valérie; Robert, Séverine; Chamberlain, Sarah; Thomas, Ian; Carine Vandaele, Ann; Bertaux, Jean-Loup

    2016-04-01

    The Solar Occultation in the Infrared (SOIR) channel mounted on top of the SPICAV instrument of the ESA's Venus Express mission has observed the atmosphere of Venus during more than eight years. This IR spectrometer (2.2-4.3 μm) with a high spectral resolution (0.12 cm-1) combined an echelle grating with an acousto-optic tunable filter for order selection. SOIR performed more than 1500 solar occultation measurements leading to about two millions spectra. The Royal Belgian Institute for Space Aeronomy (BIRA-IASB) was in charge of SOIR's development and operations as well as its data pipeline. BIRA-IASB carried out several studies on the composition of Venus mesosphere and lower thermosphere: carbon dioxide, carbon monoxide, hydrogen halide (HF, HCl, DF, DCl), sulfur dioxide, water (H2O, HDO) as well as sulphuric acid aerosols in the upper haze of Venus. Density and temperature profiles of the upper atmosphere of Venus (60 km to 170 km) at the terminator have been retrieved from SOIR's spectra using different assumptions, wherein the hydrostatic equilibrium and the local thermodynamical equilibrium in the radiative transfer calculations. These results allow us to produce an Atmospheric model of Venus called Venus Atmosphere from SOIR measurements at the Terminator (VAST). Data obtained by SOIR will also contribute to update the Venus International Reference Atmosphere (VIRA). Recently, the treatment of the raw data to transmittance has been optimized, and a new dataset of spectra has been produced. All raw spectra (PSA level 2) as well as calibrated spectra (PSA level 3) have been delivered to ESA's Planetary Science Archive (PDSPSA). Consequently the re-analysis of all spectra has been undergone. We will briefly present the improvements implemented in the data pipeline. We will also show a compilation of results obtained by the instrument considering the complete mission duration.

  6. Windows to the Universe: A Case Study on the Use of the Web for Science Literacy and Education

    Science.gov (United States)

    Johnson, R.; Bergman, J.; Deardorff, R.; Henderson, S.; Mastie, D.; Kozyra, J.; Lopez, R.; Clauer, R.; Gombosi, T.; Olsen, G.

    The world-wide web can be a powerful tool for reaching the public as well as students and teachers around the world, supporting both formal and informal science education. The Windows to the Universe Project, in itiated in 1995, provides a case study of approaches for the use of the web to support space science education and literacy efforts and lessons learned. Through the use of innovative approaches such as attractive design, multi-level content, science concepts presented in a broader background context that includes connections to culture and the humanities, supporting technologies, and interactive learning activities, a large audience of learners around the world regularly use the web site to learn about space science. User surveys show that approximately 65% of the 4.3 million users of the website in 2001 were K-12 students, and 46% of the users accessed the site at least once per week. By including educators in the project as co-designers from its inception, and by aggressively utilizing and providing professional development opportunities for educators, the web site is now used by thousands of educators around the world as a supplementary resource for their classroom. During the course of the project, we have developed tools to help us interact with and respond to our users and to evaluate the effectiveness of our design and content. We are now implementing an evaluation program through which we will assess the impact of the project in educational settings. With its large audience, content base, and established professional development and dissemination effort, the Windows to the Universe project is now used as a high leverage education and outreach tool for numerous space science research programs, including the Space Physics and Aeronomy Research Collaboratory, the Comprehensive Space Environment Model, the Space Weather Modeling Framework, and the Center for Integrated Space Weather Modeling. Core funding for the project is provided from the Office of

  7. Why Are Hyperbolic Micrometeors No Longer Detected with the Arecibo UHF Radar ?

    Science.gov (United States)

    Meisel, D. D.; Bartlett, B. D.; Mathews, J. D.; Janches, D.; Briczinski, S.

    2004-05-01

    Micrometeor detections using the AO UHF radar have been carried out since 1997. During 1997-2000, hyperbolic (presumed extrasolar origin) orbits were obtained for about 3% of the some 30,000 detections (Meisel et al. 2003 on publicly available from the author CD-ROM and Meisel et al. Ap.J. 567, 323 2002a, Ap.J. 579,895 2002b). In one of those papers (2002a), it was predicted that Jupiter was (over the next 3 to 5 years) going to move into the predominant radiant direction of the extrasolar orbits, i.e. the local interstellar bubble. Thus it was expected that the number of extrasolar meteors would diminish. What was not expected was, however, that so far in 2001-2004 no hyperbolic orbits have been found among nearly 20,000 more orbits. At the size range of the detected micrometeors, perturbations by the major planets, solar photons as well as solar wind particle charging and magnetic field interactions must be taken into account. Thus the apparent Jovian perturbing forces (even on elliptical orbits) seems to exceed that provided by gravity alone and is likely to involve action by the extensive Jovian magnetosphere. The situation in the future promises to be even more confused because Saturn will be moving through the same radiant area even as Jupiter moves out. The micrometeor flux is continuing to be closely monitored from AO. This research is supported through NSF Planetary Astronomy and Aeronomy grants AST0205974, AST9801590, and NRA9612055007. Radar time is provided by NAIC, Arecibo Observatory operated for the National Science Foundation through a cooperative agreement with Cornell University.

  8. Distribution of Atomic Hydrogen in the Upper Atmosphere: Assessment of Absolute Densities and Variations in the light of Recent Observations

    Science.gov (United States)

    Bishop, J.

    2002-12-01

    Knowledge of atomic hydrogen densities ([H](z)) in the upper atmosphere is important both for understanding mesospheric-lower thermospheric (MLT) chemistry and for realistic modeling of geocoronal interactions with ionized populations (e.g., plasmasphere, ring current). Work culminating in the 1970's failed to achieve consistent determinations of the distribution of atomic hydrogen; because of this, the relevance of [H](z) determinations in other areas of aeronomic research has remained unacknowledged. Extensive independent sets of optical data, coupled with improved solar Lyman line series irradiances and corrections of assumptions used in the earlier data analyses, however, now enable us to resolve the older inconsistencies and pursue determination of quantities of genuine interest: thermospheric atomic hydrogen vertical fluxes, characteristics of the satellite atom component in the geocorona, etc. These data sets include: Wisconsin Hα\\ Mapper (WHAM) Fabry-Perot data from Kitt Peak Observatory, providing ~ \\ 40,000\\ spectra of geocoronal and galactic Balmer~α intensities beginning in 1997; very high resolution Fabry-Perot data from Pine Bluff Observatory (Wisconsin) of both Balmer~α\\ and Balmer~β\\ intensities and line profiles from 2000-2001; FUSE EUV measurements of Lyman line series intensities from 1999 and 2000 (excluding Lyman~α); MiniSat1/EURD EUV spectrometer measurements of Lyman line series intensities (excluding Lyman~α) from 1997 to 2001; and IMAGE/GEO Lyman~α\\ intensity data from geocoronal positions (satellite apogees ~ 7~R E). In this presentation, modeling analyses of representative data subsets will be discussed, focusing on results relevant to broader aeronomy topics.

  9. Visible spectral imager for occultation and nightglow (VISION) for the PICASSO Mission

    Science.gov (United States)

    Saari, Heikki; Näsilä, Antti; Holmlund, Christer; Mannila, Rami; Näkki, Ismo; Ojanen, Harri J.; Fussen, Didier; Pieroux, Didier; Demoulin, Philippe; Dekemper, Emmanuel; Vanhellemont, Filip

    2015-10-01

    PICASSO - A PICo-satellite for Atmospheric and Space Science Observations is an ESA project led by the Belgian Institute for Space Aeronomy, in collaboration with VTT, Clyde Space Ltd. (UK), and the Centre Spatial de Liège (BE). VTT Technical Research Centre of Finland Ltd. will deliver the Visible Spectral Imager for Occultation and Nightglow (VISION) for the PICASSO mission. The VISION targets primarily the observation of the Earth's atmospheric limb during orbital Sun occultation. By assessing the radiation absorption in the Chappuis band for different tangent altitudes, the vertical profile of the ozone is retrieved. A secondary objective is to measure the deformation of the solar disk so that stratospheric and mesospheric temperature profiles are retrieved by inversion of the refractive raytracing problem. Finally, occasional full spectral observations of polar auroras are also foreseen. The VISION design realized with commercial of the shelf (CoTS) parts is described. The VISION instrument is small, lightweight (~500 g), Piezo-actuated Fabry-Perot Interferometer (PFPI) tunable spectral imager operating in the visible and near-infrared (430 - 800 nm). The spectral resolution over the whole wavelength range will be better than 10 nm @ FWHM. VISION has is 2.5° x 2.5° total field of view and it delivers maximum 2048 x 2048 pixel spectral images. The sun image size is around 0.5° i.e. ~500 pixels. To enable fast spectral data image acquisition VISION can be operated with programmable image sizes. VTT has previously developed PFPI tunable filter based AaSI Spectral Imager for the Aalto-1 Finnish CubeSat. In VISION the requirements of the spectral resolution and stability are tighter than in AaSI. Therefore the optimization of the of the PFPI gap control loop for the operating temperature range and vacuum conditions has to be improved. VISION optical, mechanical and electrical design is described.

  10. Non-adiabatic dynamics of reactions of O(1D) with Xe, CO, NO2, and CO2 from crossed atomic and molecular beam experiments

    Science.gov (United States)

    Boering, Kristie

    2015-03-01

    Reactions of the first excited state of atomic oxygen, O(1D), with small molecules such as CO, NO2, and CO2 continue to be of interest in aeronomy and atmospheric chemistry, thus providing additional motivation to understand the dynamics of these reactions and how well they are predicted by theory. In collaboration with Prof. Jim Lin of the Institute of Atomic and Molecular Sciences, Academia Sinica, Taiwan, we have studied the dynamics of quenching and non-quenching reactions between O(1D) and various small molecules using a universal crossed atomic and molecular beam apparatus. New experimental results for the dynamics of quenching of O(1D) by Xe and CO will be presented and compared with previous results for NO2 (K.A. Mar, A.L. Van Wyngarden, C.-W. Liang, Y.T. Lee, J.J. Lin, K.A. Boering, J. Chem. Phys., 137, 044302, doi: 10.1063/1.4736567, 2012) and CO2 (M.J. Perri, A.L. Van Wyngarden, K.A. Boering, J.J. Lin, and Y.T. Lee, J. Chem. Phys., 119(16), 8213-8216, 2003; M.J. Perri, A.L. Van Wyngarden, J.J. Lin, Y.T. Lee, and K.A. Boering, J. Phys. Chem. A, 108(39), 7995-8001, doi: 10.1021/jp0485845, 2004). Among the most intriguing of the new results are for quenching of O(1D) by Xe, for which marked oscillations in the differential cross sections were observed for the O(3P) and Xe products. The shape and relative phase of the oscillatory structure depended strongly on collision energy. This behavior is likely due to the quantum nature of the collision dynamics, caused by interferences among multiple curve crossing pathways accessible during electronic quenching, known as Stueckelberg oscillations.

  11. Small Whiskbroom Imager for atmospheric compositioN monitorinG (SWING) from an Unmanned Aerial Vehicle (UAV): Results from the 2014 AROMAT campaign

    Science.gov (United States)

    Merlaud, Alexis; Tack, Frederik; Constantin, Daniel; Fayt, Caroline; Maes, Jeroen; Mingireanu, Florin; Mocanu, Ionut; Georgescu, Lucian; Van Roozendael, Michel

    2015-04-01

    The Small Whiskbroom Imager for atmospheric compositioN monitorinG (SWING) is an instrument dedicated to atmospheric trace gas retrieval from an Unmanned Aerial Vehicle (UAV). The payload is based on a compact visible spectrometer and a scanning mirror to collect scattered sunlight. Its weight, size, and power consumption are respectively 920 g, 27x12x12 cm3, and 6 W. The custom-built 2.5 m flying wing UAV is electrically powered, has a typical airspeed of 100 km/h, and can operate at a maximum altitude of 3 km. Both the payload and the UAV were developed in the framework of a collaboration between the Belgian Institute for Space Aeronomy (BIRA-IASB) and the Dunarea de Jos University of Galati, Romania. We present here SWING-UAV test flights dedicated to NO2 measurements and performed in Romania on 10 and 11 September 2014, during the Airborne ROmanian Measurements of Aerosols and Trace gases (AROMAT) campaign. The UAV performed 5 flights in the vicinity of the large thermal power station of Turceni (44.67° N, 23.4° E). The UAV was operated in visual range during the campaign, up to 900 m AGL , downwind of the plant and crossing its exhaust plume. The spectra recorded on flight are analyzed with the Differential Optical Absorption Spectroscopy (DOAS) method. The retrieved NO2 Differential Slant Column Densities (DSCDs) are up to 1.5e17 molec/cm2 and reveal the horizontal gradients around the plant. The DSCDs are converted to vertical columns and compared with coincident car-based DOAS measurements. We also present the near-future perspective of the SWING-UAV observation system, which includes flights in 2015 above the Black Sea to quantify ship emissions, the addition of SO2 as a target species, and autopilot flights at higher altitudes to cover a typical satellite pixel extent (10x10 km2).

  12. An Albedo-Ice Regression Method for Determining Ice Water Content of Polar Mesospheric Clouds from UV Observations

    Science.gov (United States)

    Thomas, G. E.; Bardeen, C.; Benze, S.

    2014-12-01

    Simulations of Polar Mesospheric Cloud (PMC) brightness and ice water content (IWC) are used to develop a simple robust method for IWC retrieval from UV satellite observations. We compare model simulations of IWC with retrievals from the UV Cloud Imaging and Particle Size (CIPS) experiment on board the satellite mission Aeronomy for Ice in the Mesosphere (AIM). This instrument remotely senses scattered brightness related to the vertically-integrated ice content. Simulations from the Whole Atmosphere Community Climate Model (WACCM), a chemistry climate model, is combined with a sectional microphysics model based on the Community Aerosol and Radiation Model for Atmospheres (CARMA). The model calculates high-resolution three-dimensional size distributions of ice particles. The internal variability is due to geographic and temporal variation of temperature and dynamics, water vapor, and meteoric dust. We examine all simulations from a single model day (we chose northern summer solstice) which contains several thousand model clouds. Accurate vertical integrations of the albedo and IWC are obtained. The ice size distributions are thus based on physical principles, rather than artificial analytic distributions that are often used in retrieval algorithms from observations. Treating the model clouds as noise-free data, we apply the CIPS algorithm to retrieve cloud particle size and IWC. The inherent "errors" in the retrievals are thus estimated. The linear dependence of IWC on albedo makes possible a method to derive IWC, called the Albedo-Ice regression method, or AIR. This method potentially unifies the variety of data from various UV experiments, with the advantages of (1) removing scattering-angle bias from cloud brightness measurements,(2) providing a physically-useful parameter (IWC),(3) deriving IWC even for faint clouds of small average particle sizes, and (4) estimating the statistical uncertainty as a random error, which bypasses the need to derive particle size.

  13. Imaging of SO2 emissions from anthropogenic sources as part of AROMAT campaign

    Science.gov (United States)

    Brenot, H. H.; Merlaud, A.; Meier, A.; Ruhtz, T.; Van Roozendael, M.; Stebel, K.; Constantin, D.; Belegante, L.; Dekemper, E.; Theys, N.; Campion, R.; Schuettemeyer, D.

    2015-12-01

    This study presents field campaign measurements of SO2 emissions from pollution source in Romania. Three types of instruments (SO2 camera, whisk and push broom imager) proceeded ground-based and airborne data acquisition as part of the AROMAT ESA project (monitoring of SO2 plume from a large thermoelectric plant). The SO2 camera used is an imaging system composed of two UV cameras (synchronised in space and time) allowing fast acquisitions of intensity. Each camera is equipped with the same lens and a specific narrow band-pass filter (one at the wavelength at which SO2 absorbs and one at an off-band wavelength). The combination of two UV cameras provides a 2D image of the integrated content of SO2. The Small Whisk broom Imager for trace gases monitoriNG (SWING) used in this study and developed at the Belgian Institute for Space Aeronomy (BIRA), is based on a compact ultra-violet visible spectrometer and a scanning mirror. The Airborne imaging instrument for Measurements of Atmospheric Pollution (AirMAP) constructed at the Institute of Environmental Physics of the University of Bremen (IUP), performed SO2 measurements in the UV-visible spectral range. Both whisk and push broom scanner use the DOAS technique, that is based on the relationship between the quantity of light absorbed and the number of SO2 molecules in the light path. SWING and AirMAP instruments provide scans of SO2 column density. Quantification of 2D field contents and fluxes of anthropogenic SO2 emissions from Turceni power station (Romania) are shown. Preparatory results from data acquisition in the harbour of Antwerp (monitoring of SO2 emissions from refinery and chemical industry) are also presented.

  14. Heliophysics as a Scientific Discipline

    Science.gov (United States)

    Greb, K.

    2015-12-01

    Heliophysics is a developing scientific discipline integrating studies of the Sun's variability, the surrounding heliosphere, and climate environments. Over the past few centuries our understanding of how the Sun drives space weather and climate on the Earth and other planets has advanced at an ever-increasing rate. NASA Living With a Star and the UCAR Visiting Scientist Progams sponsor the annual Heliophysics Summer Schools to build the next generation of scientists in this emerging field. The highly successful series of the summer schools (commencing 2007) trains a select group of graduate students, postdoctoral fellows and university faculty to learn and develop the science of heliophysics as a broad, coherent discipline that reaches in space from the Earth's troposphere to the depths of the Sun, and in time from the formation of the solar system to the distant future. Now in its tenth year, the School has resulted in the publication of five Heliophysics textbooks now being used at universities worldwide. The books provide a foundational reference for researchers in space physics, solar physics, aeronomy, space weather, planetary science and climate science, astrophysics, plasma physics,. In parallel, the School also developed the complementary materials that support teaching of heliophysics at both graduate and undergraduate levels. The Jack Eddy Postdoctoral Fellowship Program matches newly graduated postdoctorates with hosting mentors for the purpose of training the next generation researchers needed in heliophysics. The fellowships are for two years, and any U.S. university or research lab may apply to host a fellow. Two major topics of focus for the program are the science of space weather and of the Sun-climate connection. Since the goal of this fellowship program is to train Sun-Earth system researchers, preference is also given to research projects that cross the traditional heliophysics subdomains of the Sun, heliosphere, magnetosphere, and ionosphere

  15. Solar-induced 27-day variations of mesospheric temperature and water vapor from the AIM SOFIE experiment: Drivers of polar mesospheric cloud variability

    Science.gov (United States)

    Thomas, Gary E.; Thurairajah, Brentha; Hervig, Mark E.; von Savigny, Christian; Snow, Martin

    2015-11-01

    Polar Mesospheric Clouds (PMCs) are known to be influenced by changes in water vapor and temperature in the cold summertime mesopause. Solar variability of these constituents has been held responsible for 11-year and 27-day variability of PMC activity, although the detailed mechanisms are not yet understood. It is also known that the solar influence on PMC variability is a minor contributor to the overall day-to-day variability, which is dominated by effects of gravity waves, planetary waves, and inter-hemispheric coupling. To address this issue, we have analyzed 15 seasons of data taken from the Solar Occultation for Ice Experiment (SOFIE) on the Aeronomy of Ice in the Mesosphere (AIM) satellite. The SOFIE data contain precise measurements of water vapor, temperature and ice water content (among other quantities). These high-latitude measurements are made during the PMC season at the terminator, and therefore directly relate to the simultaneous measurements of mesospheric ice. Using a composite data set of Lyman-α irradiance, we correlated the time variation of the atmospheric variables with the 27-day variability of solar ultraviolet irradiance. We used a combination of time-lagged linear regression and Superposed Epoch Analysis to extract the solar contribution as sensitivity values (response/forcing) vs. height. We compare these results to previously published results, and show that the temperature sensitivity is somewhat higher, whereas the water sensitivity is nearly the same as published values. The time lags are shorter than that expected from direct solar heating and photodissociation, suggesting that the responses are due to 27-day variations of vertical winds. An analytic solution for temperature changes forced by solar irradiance variations suggests that if the response is due purely to Lyman-α heating and Newtonian cooling, the response should vary throughout the summertime season and depend primarily upon the height-dependent column density of

  16. SOIR and NOMAD: Characterization of Planetary Atmospheres

    Science.gov (United States)

    Robert, S.; Chamberlain, S.; Mahieux, A.; Thomas, I.; Wilquet, V.; Vandaele, A. C.

    2014-06-01

    The Belgian Institute for Space Aeronomy is involved in the Venus Express mission (VeX), launched in 2006 and in the ExoMars Trace Gas Orbiter mission (TGO), due for launch in 2016. BISA is responsible for one instrument in each mission, SOIR onboard VeX and NOMAD onboard TGO respectively. The SOIR instrument onboard Venus Express allows observations of trace gases in the Venus atmosphere, at the terminator for both the morning and evening sides of the planet and for almost all latitudes. It has been designed to measure spectra in the IR region (2.2 - 4.3 µm) of the Venus atmosphere using the solar occultation technique1. This method derives unique information on the vertical composition and structure of the mesosphere and lower thermosphere2,3,4,5. It is unique in terms of spectral coverage and spectral resolution (0.15 cm-1), and is ideally designed to probe the Venus atmosphere for CO2 as well as trace gases, such as H2O, CO, HCl and HF. SOIR is capable of (1) providing vertical information on a broad series of species, such as CO2, CO, H2O, HCl, HF, SO26 and aerosols 7, covering the so far sparsely known region located above the clouds, (2) contributing to a better understanding of the dynamics and stability of the atmosphere by delivering total density and kinetic temperature profiles at the terminator, an up-to-now still unchartered region, and (3) detecting weak absorption bands of rare CO2 isotopologues8, due to the sensitivity of SOIR, the high concentration of CO2 on Venus and the long absorption paths sounded during solar occultations.

  17. Proceedings of the XIIIth IAGA Workshop on Geomagnetic Observatory Instruments, Data Acquisition, and Processing

    Science.gov (United States)

    Love, Jeffrey J.

    2009-01-01

    The thirteenth biennial International Association of Geomagnetism and Aeronomy (IAGA) Workshop on Geomagnetic Observatory Instruments, Data Acquisition and Processing was held in the United States for the first time on June 9-18, 2008. Hosted by the U.S. Geological Survey's (USGS) Geomagnetism Program, the workshop's measurement session was held at the Boulder Observatory and the scientific session was held on the campus of the Colorado School of Mines in Golden, Colorado. More than 100 participants came from 36 countries and 6 continents. Preparation for the workshop began when the USGS Geomagnetism Program agreed, at the close of the twelfth workshop in Belsk Poland in 2006, to host the next workshop. Working under the leadership of Alan Berarducci, who served as the chairman of the local organizing committee, and Tim White, who served as co-chairman, preparations began in 2007. The Boulder Observatory was extensively renovated and additional observation piers were installed. Meeting space on the Colorado School of Mines campus was arranged, and considerable planning was devoted to managing the many large and small issues that accompany an international meeting. Without the devoted efforts of both Alan and Tim, other Geomagnetism Program staff, and our partners at the Colorado School of Mines, the workshop simply would not have occurred. We express our thanks to Jill McCarthy, the USGS Central Region Geologic Hazards Team Chief Scientist; Carol A. Finn, the Group Leader of the USGS Geomagnetism Program; the USGS International Office; and Melody Francisco of the Office of Special Programs and Continuing Education of the Colorado School of Mines. We also thank the student employees that the Geomagnetism Program has had over the years and leading up to the time of the workshop. For preparation of the proceedings, thanks go to Eddie and Tim. And, finally, we thank our sponsors, the USGS, IAGA, and the Colorado School of Mines.

  18. Obituary: Thomas Michael Donahue, 1921-2004

    Science.gov (United States)

    Gombosi, Tamás I.

    2004-12-01

    Thomas M. Donahue, one of the nation's leading space and planetary scientists and a pioneer of space exploration, died Saturday October 16, 2004, from complications following heart surgery. The Edward H. White II Distinguished University Professor of Planetary Science at the University of Michigan, Tom shaped space exploration through his scientific achievements and policy positions. His work started with the first use of sounding rockets following World War II and continued for almost 60 years. Tom was born in Healdton, Oklahoma on May 23, 1921 to Robert Emmet and Mary (Lyndon) Donahue. His father was a plumber in the oil fields when Tom was born (Healdton OK was an oil town) and worked as a plumber in Kansas City for a time. Tom grew up in Kansas City, graduating in 1942 from Rockhurst College in that city with degrees in classics and physics. His graduate work in physics at Johns Hopkins University was interrupted by service in the Army Signal Corps. He obtained his PhD degree in atomic physics from Hopkins in the fall of 1947. After three years as a post-doctoral research associate and assistant professor at Hopkins, Tom joined the University of Pittsburgh Physics Department in 1951. At Pittsburgh he organized an atomic physics and atmospheric science program that led to experimental and theoretical studies of the upper atmosphere of the Earth and other solar system planets with instruments flown on sounding rockets and spacecraft. He became Professor of Physics in 1959 and eventually Director of the Laboratory for Atmospheric and Space Sciences and the Space Research Coordination Center at the University. In 1960 he spent a sabbatical year on a Guggenheim Fellowship at the Service d'Aeronomie in Paris, which began collaborations with French colleagues that flourished for more than 40 years. In 1974 he became the Chairman of the Atmospheric and Oceanic Science Department, University of Michigan, a position he held until 1981. In 1986, he was named the Henry

  19. 2013年IAGA科学大会与岩石圈磁异常研究进展%IAGA 2013 scientific assembly and progress of research on lithospheric magnetic anomalies

    Institute of Scientific and Technical Information of China (English)

    袁洁浩; 陈斌; 王粲; 狄传芝; 徐如刚; 倪喆

    2014-01-01

    The 12 th Scientific Assembly of the International Association of Geomag-netism and Aeronomy (IAGA)was held in Merida,Yucatan,Mexica during August 26~31, 2013.This IAGA Scientific Assembly showed the new progresses and new results obtained through the observations and researches on the five divisions:the internal magnetic field,the aeronomic phenomena,the magnetospheric phenomena,the solar wind and the interplanetar-y field,the geomagnetic observatories,the survey and analyses.New progress of the session on the “Modelling and interpretation of lithospheric magnetic anomalies”was presented dur-ing the 12th IAGA Scientific Assembly.This session shows that the research on the lithos-pheric magnetic anomalies not only has important significance in geomagnetism research,but also can be used in a wide application.The relation between the anomalous changes of the lithospheric magnetic field and earthquakes is an important way in the study on the seis-momagnetic research,and it should be analyzed and researched further in the future.%2013年8月26~31日,在墨西哥的梅里达召开了第12届国际地磁学与高空物理学协会(IAGA)科学大会。这次 IAGA科学大会展示了地球内部磁场、高空物理现象、磁层现象、太阳风与行星际磁场、地磁台站及测量与分析等各部分的观测与研究所获得的新进展与新成果。在第12届IAGA科学大会期间召开的岩石圈磁异常的摸拟与解释“专题学术讨论会,显示了岩石圈磁异常研究的新进展。该专题讨论会充分表明,岩石圈磁异常的研究不仅具有重要的地磁学意义,而且具有广泛的实际应用。岩石圈磁异常变化与地震的关系是震磁研究中具有重要意义的探索途径,今后应当深入地分析与研究。

  20. Undergraduate space science program at Alabama A&M University

    Science.gov (United States)

    Lal, R.; Tan, A.; Lyatsky, W.

    A new undergraduate Physics Program with Space Science as the major concentration area has been initiated at Alabama A&M University (AAMU) in 2001. This program is funded by NASAÆs OSS and OEOP Offices under the NRA 00-OSS-02 Minority University Education and Research Partnership Initiative in Space Science-2000. The partner institutions are NASA Marshall Space Flight Center (MSFC) and Goddard Space Flight Center (GSFC), Lawrence Livermore National Laboratory (LLNL) and The University of Alabama in Huntsville (UAH). A primary objective of this Program is to train undergraduate and graduate minority (principally African-American) students in the extremely underrepresented areas of Space Science and to prepare them for eventual teaching and/or research careers in this increasingly important field. The best way to achieve this is to recruit students early from high school, and not wait until they have already selected their specialty in college. Also, a student with a BS degree in Physics with specialization in Space Science will have a decisive advantage in pursuing graduate studies in Space Science than the others. The BS degree requires a student to take 30 credit hours of Physics courses and an additional 18 hours in the chosen area of concentration. Several basic traditional courses in Lower Atmosphere, Aeronomy, the Solar System and Orbital Mechanics have been developed. Additional courses in Plasma Physics, Solar Physics and Astronomy will be taught by NASA-MSFC scientists and UAH faculty. A parallel objective is to expose the student to research experience early in their ca- reers. Each student is required to complete a one semester Undergraduate Research Opportunity Project (UROP) on a relevant topic from Space Science. The students will be guided in research by AAMU and UAH faculty and MSFC scientists. Each student will be required to write a term paper and make an oral presentation before a committee of advisors. This experience will enhance the Space

  1. StarGuides Plus

    Science.gov (United States)

    Heck, A.

    StarGuides Plus represents the most comprehensive and accurately validated collection of practical data on organizations involved in astronomy, related space sciences and other related fields. This invaluable reference source (and its companion volume, StarBriefs Plus) should be on the reference shelf of every library, organization or individual with any interest in these areas. The coverage includes relevant universities, scientific committees, institutions, associations, societies, agencies, companies, bibliographic services, data centers, museums, dealers, distributors, funding organizations, journals, manufacturers, meteorological services, national norms & standard institutes, parent associations & societies, publishers, software producers & distributors, and so on. Besides astronomy and associated space sciences, related fields such as aeronautics, aeronomy, astronautics, atmospheric sciences, chemistry, communications, computer sciences, data processing, education, electronics, engineering, energetics, environment, geodesy, geophysics, information handling, management, mathematics, meteorology, optics, physics, remote sensing, and so on, are also covered where appropriate. After some thirty years in continuous compilation, verification and updating, StarGuides Plus currently gathers together some 6,000 entries from 100 countries. The information is presented in a clear, uncluttered manner for direct and easy use. For each entry, all practical data are listed: city, postal and electronic-mail addresses, telephone and fax numbers, URLs for WWW access, foundation years, numbers of members and/or numbers of staff, main activities, publications titles (with frequencies, ISS-Numbers and circulations), names and geographical coordinates of observing sites, names of planetariums, awards (prizes and/or distinctions) granted, etc. The entries are listed alphabetically in each country. An exhaustive index gives a breakdown not only by different designations and

  2. Patrol of the short wavelength activity and flares of Sun as star

    Science.gov (United States)

    Afanasiev, I.; Avakyan, S.; Leonov, N.; Serova, A.; Voronin, N.

    Monitoring of the spectral range which most affects solar-terrestrial relationship - soft X-ray and extreme UV-radiations allows to solve ? problem of solar activity influence on all aspects of the Sun - Earth ties and to select the most important precursors of solar flares and the solar events related with a flare (such as proton events, high-velocity plasma streams in the solar wind, shock waves, coronal mass ejection and, the most important, the beginning of principal magnetic storms). Solar activity is constantly monitored at present (in the USA) only in two sections of the spectrum of ionizing radiation: 115 (119) nm. However, so far there has been no monitoring of the flux in the most geoeffective region of the spectrum (0.8-115 nm) from the entire disk of the sun; this region completely monitors the main part of the ionosphere of the earth and the ionosphere of the other planets of the solar system, including the formation and status of the main ionospheric maxima. This occurs solely because of technical and methodological difficulties in performing the measurements and calibration in this spectral range on spacecraft, because it is necessity to use only windowless optics. At the present the solar the optical - electronic equipment (OEE) is testing and there are plans to launch OEE of Space Solar Patrol (SSP) consisting of solar radiometers and spectrometers at the Russian Module of the International Space Station. So the solving the problem of the permanent monitoring-patrol of ionizing radiation from the full disk of the Sun appears in the main tasks of fundamental scientific studies in space. The results of this monitoring can be contribution in development of simultaneous studies in several sciences, such as: - solar astrophysics (state of all solar atmospheric regions), - meteorology, physics of atmosphere (the influence of solar activity on global changes, climate and weather including the effects of atmo s pheric electricity), - aeronomy, astronautics

  3. 27-day solar forcing of mesospheric temperature, water vapor and polar mesospheric clouds from the AIM SOFIE and CIPS satellite experiments

    Science.gov (United States)

    Thomas, Gary; Thurairajah, Brentha; von Savigny, Christian; Hervig, Mark; Snow, Martin

    2016-04-01

    Solar cycle variations of ultraviolet radiation have been implicated in the 11-year and 27-day variations of Polar Mesospheric Cloud (PMC) properties. Both of these variations have been attributed to variable solar ultraviolet heating and photolysis, but no definitive studies of the mechanisms are available. The solar forcing issue is critical toward answering the broader question of whether PMC's have undergone long-term changes, and if so, what is the nature of the responsible long-term climate forcings? One of the principal goals of the Aeronomy of Ice in the Mesosphere satellite mission was to answer the question: "How does changing solar irradiance affect PMCs and the environment in which they form?" We describe an eight-year data set from the AIM Solar Occultation for Ice Experiment (SOFIE) and the AIM Cloud Imaging and Particle Size (CIPS) experiment. Together, these instruments provide high-precision measurements of high-latitude summertime temperature (T), water vapor (H2O), and PMC ice properties for the period 2007-present. The complete temporal coverage of the summertime polar cap region for both the primary atmospheric forcings of PMC (T and H2O), together with a continually updated time series of Lyman-alpha solar irradiance, allows an in-depth study of the causes and effects of 27-day PMC variability. The small responses of these variables, relative to larger day-to-day changes from gravity waves, tides, inter-hemispheric coupling, etc. require a careful statistical analysis to isolate the solar influence. We present results for the 27-day responses of T, H2O and PMC for a total of 15 PMC seasons, (30 days before summer solstice to 60 days afterward, for both hemispheres). We find that the amplitudes and phase relationships are not consistent with the expected mechanisms of solar UV heating and photolysis - instead we postulate a primarily dynamical response, in which a periodic vertical wind heats/cools the upper mesosphere, and modulates PMC

  4. Variations in the geomagnetic and gravitational background associated with two strong earthquakes of the May 2012 sequence in the Po Valley Plain (Italy).

    Science.gov (United States)

    Straser, Valentino

    2013-04-01

    characteristics (duration, extension, intensity, etc..) compatible with: the classification by IAGA (International Association of Geomagnetism and Aeronomy) of geomagnetic pulsations; emissions of an anthropic type; known natural emissions (Whistler, Chorus, lightning, electrophonic meteoric sounds, plasma, etc..). For this reason, since Radio anomalies are not related to known phenomena they were considered in this study as candidate seismic precursors. Most of the radio anomalies are observed below 32Hz and, generally, between 0.1 and 20Hz and occur in association with an intense increase in the geomagnetic background that precedes the occurrence of a seismic event.

  5. Space Weather Forecasting: An Enigma

    Science.gov (United States)

    Sojka, J. J.

    2012-12-01

    The space age began in earnest on October 4, 1957 with the launch of Sputnik 1 and was fuelled for over a decade by very strong national societal concerns. Prior to this single event the adverse effects of space weather had been registered on telegraph lines as well as interference on early WWII radar systems, while for countless eons the beauty of space weather as mid-latitude auroral displays were much appreciated. These prior space weather impacts were in themselves only a low-level science puzzle pursued by a few dedicated researchers. The technology boost and innovation that the post Sputnik era generated has almost single handedly defined our present day societal technology infrastructure. During the decade following Neil's walk on the moon on July 21, 1969 an international thrust to understand the science of space, and its weather, was in progress. However, the search for scientific understand was parsed into independent "stove pipe" categories: The ionosphere-aeronomy, the magnetosphere, the heliosphere-sun. The present day scientific infrastructure of funding agencies, learned societies, and international organizations are still hampered by these 1960's logical divisions which today are outdated in the pursuit of understanding space weather. As this era of intensive and well funded scientific research progressed so did societies innovative uses for space technologies and space "spin-offs". Well over a decade ago leaders in technology, science, and the military realized that there was indeed an adverse side to space weather that with each passing year became more severe. In 1994 several U.S. agencies established the National Space Weather Program (NSWP) to focus scientific attention on the system wide issue of the adverse effects of space weather on society and its technologies. Indeed for the past two decades a significant fraction of the scientific community has actively engaged in understanding space weather and hence crossing the "stove

  6. Comparing nadir and limb observations of polar mesospheric clouds: The effect of the assumed particle size distribution

    Science.gov (United States)

    Bailey, Scott M.; Thomas, Gary E.; Hervig, Mark E.; Lumpe, Jerry D.; Randall, Cora E.; Carstens, Justin N.; Thurairajah, Brentha; Rusch, David W.; Russell, James M.; Gordley, Larry L.

    2015-05-01

    Nadir viewing observations of Polar Mesospheric Clouds (PMCs) from the Cloud Imaging and Particle Size (CIPS) instrument on the Aeronomy of Ice in the Mesosphere (AIM) spacecraft are compared to Common Volume (CV), limb-viewing observations by the Solar Occultation For Ice Experiment (SOFIE) also on AIM. CIPS makes multiple observations of PMC-scattered UV sunlight from a given location at a variety of geometries and uses the variation of the radiance with scattering angle to determine a cloud albedo, particle size distribution, and Ice Water Content (IWC). SOFIE uses IR solar occultation in 16 channels (0.3-5 μm) to obtain altitude profiles of ice properties including the particle size distribution and IWC in addition to temperature, water vapor abundance, and other environmental parameters. CIPS and SOFIE made CV observations from 2007 to 2009. In order to compare the CV observations from the two instruments, SOFIE observations are used to predict the mean PMC properties observed by CIPS. Initial agreement is poor with SOFIE predicting particle size distributions with systematically smaller mean radii and a factor of two more albedo and IWC than observed by CIPS. We show that significantly improved agreement is obtained if the PMC ice is assumed to contain 0.5% meteoric smoke by mass, in agreement with previous studies. We show that the comparison is further improved if an adjustment is made in the CIPS data processing regarding the removal of Rayleigh scattered sunlight below the clouds. This change has an effect on the CV PMC, but is negligible for most of the observed clouds outside the CV. Finally, we examine the role of the assumed shape of the ice particle size distribution. Both experiments nominally assume the shape is Gaussian with a width parameter roughly half of the mean radius. We analyze modeled ice particle distributions and show that, for the column integrated ice distribution, Log-normal and Exponential distributions better represent the range

  7. A chemical model of meteoric ablation

    Directory of Open Access Journals (Sweden)

    T. Vondrak

    2008-12-01

    Full Text Available Most of the extraterrestrial dust entering the Earth's atmosphere ablates to produce metal vapours, which have significant effects on the aeronomy of the upper mesosphere and lower thermosphere. A new Chemical Ablation Model (CAMOD is described which treats the physics and chemistry of ablation, by including the following processes: sputtering by inelastic collisions with air molecules before the meteoroid melts; evaporation of atoms and oxides from the molten particle; diffusion-controlled migration of the volatile constituents (Na and K through the molten particle; and impact ionization of the ablated fragments by hyperthermal collisions with air molecules. Evaporation is based on thermodynamic equilibrium in the molten meteoroid (treated as a melt of metal oxides, and between the particle and surrounding vapour phase. The loss rate of each element is then determined assuming Langmuir evaporation. CAMOD successfully predicts the meteor head echo appearance heights, observed from incoherent scatter radars, over a wide range of meteoroid velocities. The model also confirms that differential ablation explains common-volume lidar observations of K, Ca and Ca+ in fresh meteor trails. CAMOD is then used to calculate the injection rates into the atmosphere of a variety of elements as a function of altitude, integrated over the meteoroid mass and velocity distributions. The most abundant elements (Fe, Mg and Si have peak injection rates around 85 km, with Na and K about 8 km higher. The more refractory element Ca ablates around 82 km with a Na:Ca ratio of 4:1, which does therefore not explain the depletion of atomic Ca to Na, by more than 2 orders of magnitude, in the upper mesosphere. Diffusion of the most volatile elements (Na and K does not appear to be rate-limiting except in the fastest meteoroids. Non-thermal sputtering causes ~35% mass loss from the fastest (~60–70 km s−1 and smallest (10−17–10

  8. Solar and Space Physics PhD Production and Job Availability: Implications for the Future of the Space Weather Research Workforce

    Science.gov (United States)

    Moldwin, M.; Morrow, C. A.; Moldwin, L. A.; Torrence, J.

    2012-12-01

    To assess the state-of-health of the field of Solar and Space Physics an analysis of the number of Ph.D.s produced and number of Job Postings each year was done for the decade 2001-2010. To determine the number of Ph.D's produced in the field, the University of Michigan Ph.D. Dissertation Archive (Proquest) was queried for Solar and Space Physics dissertations produced in North America. The field generated about 30 Ph.D. per year from 2001 to 2006, but then saw the number increase to 50 to 70 per year for the rest of the decade. Only 14 institutions account for the majority of Solar and Space Physics PhDs. To estimate the number of jobs available each year in the field, a compilation of the job advertisements listed in the American Astronomical Society's Solar Physics Division (SPD) and the American Geophysical Union's Space Physics and Aeronomy (SPA) electronic newsletters was done. The positions were sorted into four types (Faculty, Post-doctoral Researcher, and Scientist/Researcher or Staff), institution type (academic, government lab, or industry) and if the position was located inside or outside the United States. Overall worldwide, 943 Solar and Space Physics positions were advertised over the decade. Of this total, 52% were for positions outside the US. Within Solar Physics, 44% of the positions were in the US, while in Space Physics 57% of the positions were for US institutions. The annual average for positions in the US were 26.9 for Solar Physics and 31.5 for Space Physics though there is much variability year-to-year particularly in Solar Physics positions outside the US. A disconcerting trend is a decline in job advertisements in the last two years for Solar Physics positions and between 2009 and 2010 for Space Physics positions. For both communities within the US in 2010, the total job ads reached their lowest levels in the decade (14), approximately half the decadal average number of job advertisements.

  9. What can be learned about Polar Mesospheric Clouds from suborbital missions?

    Science.gov (United States)

    Thomas, G. E.; McClintock, W.; Fritts, D. C.

    2011-12-01

    Noctilucent clouds ('night luminous' or NLC) are the highest and coldest clouds in the atmosphere. When viewed from the ground they are referred to as NLC. Viewed from space they are called Polar Mesospheric Clouds, or PMC. Occupying a narrow (81-86 km) height zone below the high-latitude mesopause (a temperature minimum versus height, located near 88 km), NLC offer a splendid sight during summer twilights. They are made visible by scattered sunlight against the dark twilight sky, when the sun lies below the horizon at angles between 6o and 16o. The state of the science has been advanced significantly since the launches of the Odin and Aeronomy of Ice in the Mesosphere (AIM) satellite missions. The spatial scales of the clouds are evident in the Cloud Imaging and Particle Size (CIPS) experiment down to its limiting resolution of 5 km. However, from ground-based photography of NLC, and from theoretical modeling of small-scale 3D instability and turbulence dynamics in the upper mesosphere, we know that there is much structure on the sub-km scale which is yet to be explored. Turbulent breakdown is expected to occur in this sub-km range. Fortunately, on the short-time scales of turbulence, ice particles should act as passive tracers, which are advected by the wind field. Sub-orbital missions provide an ideal observing platform for extending the PMC 'spatial spectrum' ranging currently from hundreds to tens of km (which we now know from CIPS) down to tens of meters, a 'leap' of three orders of magnitude. A high resolution camera with a CMOS chip, is easily capable of sub-km resolution, with S/N ratios exceeding 100 for a bright PMC. A wide (150 nm) bandpass centered on the blue portion of the PMC spectrum isolates the most intense portion of the scattered brightness. Movies of the clouds as the sub-orbital vehicle approaches, and penetrates the cloud, would be valuable, both for the scientific goal of studying the 'transition to turbulence', but also for educational

  10. Tomographic retrieval of water vapour and temperature around polar mesospheric clouds using Odin-SMR

    Directory of Open Access Journals (Sweden)

    O. M. Christensen

    2014-11-01

    Full Text Available A special observation mode of the Odin satellite provides the first simultaneous measurements of water vapour, temperature and polar mesospheric cloud (PMC brightness over a large geographical area while still resolving both horizontal and vertical structures in the clouds and background atmosphere. The observation mode has been activated during June, July and August of 2010, 2011 and 2014, and for latitudes between 50 and 82° N. This paper focuses on the water vapour and temperature measurements carried out with Odin's sub-millimetre radiometer (SMR. The tomographic retrieval approach used provides water vapour and temperature between 75–90 km with a vertical resolution of about 2.5 km and a horizontal resolution of about 200 km. The precision of the measurements is estimated to 0.5 ppm for water vapour and 3 K for temperature. Due to limited information about the pressure at the measured altitudes, the results have large uncertainties (> 3 ppm in the retrieved water vapour. These errors, however, influence mainly the mean atmosphere retrieved for each orbit, and variations around this mean are still reliably captured by the measurements. SMR measurements are performed using two different mixer chains, denoted as frequency mode 19 and 13. Systematic differences between the two frontends have been noted. A first comparison with the Solar Occultation For Ice Experiment instrument (SOFIE on-board the Aeronomy of Ice in the Mesosphere (AIM satellite and the Fourier Transform Spectrometer of the Atmospheric Chemistry Experiment (ACE-FTS on-board SCISAT indicates that the measurements using the frequency mode 19 have a significant low bias in both temperature (> 20 K and water vapour (> 1 ppm, while the measurements using frequency mode 13 agree with the other instruments considering estimated errors. PMC brightness data are provided by the OSIRIS, Odin's other sensor. Combined SMR and OSIRIS data for some example orbits are considered. For these

  11. A chemical model of meteoric ablation

    Directory of Open Access Journals (Sweden)

    T. Vondrak

    2008-07-01

    Full Text Available Most of the extraterrestrial dust entering the Earth's atmosphere ablates to produce metal vapours, which have significant effects on the aeronomy of the upper mesosphere and lower thermosphere. A new Chemical Ablation Model (CAMOD is described which treats the physics and chemistry of ablation, by including the following processes: sputtering by inelastic collisions with air molecules before the meteoroid melts; evaporation of atoms and oxides from the molten particle; diffusion-controlled migration of the volatile constituents (Na and K through the molten particle; and impact ionization of the ablated fragments by hyperthermal collisions with air molecules. Evaporation is based on thermodynamic equilibrium in the molten meteoroid (treated as a melt of metal oxides, and between the particle and surrounding vapour phase. The loss rate of each element is then determined assuming Langmuir evaporation. CAMOD successfully predicts the meteor head echo appearance heights, observed from incoherent scatter radars, over a wide range of meteoroid velocities. The model also confirms that differential ablation explains common-volume lidar observations of K, Ca and Ca+ in fresh meteor trails. CAMOD is then used to calculate the injection rates into the atmosphere of a variety of elements as a function of altitude, integrated over the meteoroid mass and velocity distributions. The most abundant elements (Fe, Mg and Si have peak injection rates around 85 km, with Na and K about 8 km higher. The more refractory element Ca ablates around 82 km with a Na:Ca ratio of 4:1, which does therefore not explain the depletion of atomic Ca to Na, by more than 2 orders of magnitude, in the upper mesosphere. Diffusion of the most volatile elements (Na and K does not appear to be rate-limiting except in the fastest meteoroids. Non-thermal sputtering causes ~35% mass loss from the fastest (~60–70 km s−1 and smallest (10−17–10

  12. Heliophysics

    Science.gov (United States)

    Austin, M.; Guhathakurta, M.; Schrijver, C. J.; Bagenal, F.; Sojka, J. J.

    2013-12-01

    Title: Heliophysics Presentation Type: Poster Current Section/Focus Group: SPA-Solar and Heliosphere Physics (SH) Current Session: SH-01. SPA-Solar and Heliosphere Physics General Contributions Authors: Meg Austin1, Madhulika Guhathakurta2, Carolus Schrijver3, Frances Bagenal4, Jan Sojka5 1. UCAR Visiting Scientist Programs 2. NASA Living With a Star Program 3. Lockheed Martin Advanced Technology Center 4. Laboratory for Atmospheric and Space Physics, University of Colorado 5. Utah State University Abstract: Heliophysics is a developing scientific discipline integrating studies of the Sun's variability, the surrounding heliosphere, and climate environments. Over the past few centuries our understanding of how the Sun drives space weather and climate on the Earth and other planets has advanced at an ever-increasing rate. NASA Living With a Star and the UCAR Visiting Scientist Progams sponsor the annual Heliophysics Summer Schools to build the next generation of scientists in this emerging field. The highly successful series of the summer schools (commencing 2007) trains a select group of graduate students, postdoctoral fellows and university faculty to learn and develop the science of heliophysics as a broad, coherent discipline that reaches in space from the Earth's troposphere to the depths of the Sun, and in time from the formation of the solar system to the distant future. The first three years of the school resulted in the publication of three textbooks now being used at universities worldwide. Subsequent years have also developed the complementary materials that support teaching of heliophysics at both graduate and undergraduate levels. The textbooks are edited by Carolus J. Schrijver, Lockheed Martin, and George L. Siscoe, Boston University. The books provide a foundational reference for researchers in heliophysics, astrophysics, plasma physics, space physics, solar physics aeronomy, space weather, planetary science and climate science. The Jack Eddy

  13. Evaluation and cross-validation of Environmental Models

    Science.gov (United States)

    Lemaire, Joseph

    Before scientific models (statistical or empirical models based on experimental measurements; physical or mathematical models) can be proposed and selected as ISO Environmental Standards, a Commission of professional experts appointed by an established International Union or Association (e.g. IAGA for Geomagnetism and Aeronomy, . . . ) should have been able to study, document, evaluate and validate the best alternative models available at a given epoch. Examples will be given, indicating that different values for the Earth radius have been employed in different data processing laboratories, institutes or agencies, to process, analyse or retrieve series of experimental observations. Furthermore, invariant magnetic coordinates like B and L, commonly used in the study of Earth's radiation belts fluxes and for their mapping, differ from one space mission data center to the other, from team to team, and from country to country. Worse, users of empirical models generally fail to use the original magnetic model which had been employed to compile B and L , and thus to build these environmental models. These are just some flagrant examples of inconsistencies and misuses identified so far; there are probably more of them to be uncovered by careful, independent examination and benchmarking. A meter prototype, the standard unit length that has been determined on 20 May 1875, during the Diplomatic Conference of the Meter, and deposited at the BIPM (Bureau International des Poids et Mesures). In the same token, to coordinate and safeguard progress in the field of Space Weather, similar initiatives need to be undertaken, to prevent wild, uncontrolled dissemination of pseudo Environmental Models and Standards. Indeed, unless validation tests have been performed, there is guaranty, a priori, that all models on the market place have been built consistently with the same units system, and that they are based on identical definitions for the coordinates systems, etc... Therefore

  14. The Scientific Committee on Antarctic Research (SCAR) in the IPY 2007-2009

    Science.gov (United States)

    Kennicutt, M. C.; Wilson, T. J.; Summerhayes, C.

    2005-05-01

    variability and change in the Antarctic as a result of natural and anthropogenic forcings over the last 100,000 years. Interhemispheric Conjugacy Effects in Solar-Terrestrial and Aeronomy Research (ICESTAR) will study the interactions between and collective behavior of the many component parts of the Earth system, including the interaction between the natural environment and human society. Objectives include specification and prediction of the state of the system and assimilation and integration of data from disparate sources to understand the complex geospace environment.

  15. Equatorial scintillations: advances since ISEA-6

    Science.gov (United States)

    Basu, Sunanda; Basu, Santimay

    1985-10-01

    Since the last equatorial aeronomy meeting in 1980, our understanding of the morphology of equatorial scintillations has advanced greatly due to more intensive observations at the equatorial anomaly locations in the different longitude zones. The unmistakable effect of the sunspot cycle in controlling irregularity belt width and electron concentration responsible for strong scintillation in the GHz range has been demonstrated. The fact that night-time F-region dynamics is an important factor in controlling the magnitude of scintillations has been recognized by interpreting scintillation observations in the light of realistic models of total electron content at various longitudes. A hypothesis based on the alignment of the solar terminator with the geomagnetic flux tubes as an indicator of enhanced scintillation occurrence and another based on the influence of a transequatorial thermospheric neutral wind have been postulated to describe the observed longitudinal variation. A distinct class of equatorial irregularities known as the bottomside sinusoidal (BSS) type has been identified. Unlike equatorial bubbles, these irregularities occur in very large patches, sometimes in excess of several thousand kilometers in the E-W direction and are associated with frequency spread on ionograms. Scintillations caused by such irregularities exist only in the VHF band, exhibit Fresnel oscillations in intensity spectra and are found to give rise to extremely long durations (~ several hours) of uninterrupted scintillations. These irregularities maximize during solstices, so that in the VHF range, scintillation morphology at an equatorial station is determined by considering occurrence characteristics of both bubble type and BSS type irregularities. The temporal structure of scintillations in relation to the in situ measurements of irregularity spatial structure within equatorial bubbles has been critically examined. A two-component irregularity spectrum with a shallow slope ( p1

  16. Titan's atmospheric sputtering and neutral torus produced by magnetospheric and pick-up ions

    Science.gov (United States)

    Michael, M.; Smith, H. T.; Johnson, R. E.; Shematovich, V.; Leblanc, F.; Ledvina, S.; Luhmann, J. H.

    As Titan does not possess an intrinsic magnetic field, Kronian magnetospheric ions can penetrate Titan's exobase as can locally produced pick-up ions (e.g. Shematovich et al. 2003). This can cause atmospheric loss and heating of the exobase region. Penetration by slowed and deflected magnetospheric ions and by the pick-up ions is described here using a 3-D Monte Carlo model (Michael et al. 2004). The incident ions can lead to the production of fast neutrals that collide with other atmospheric neutrals producing the ejection of both atomic and molecular nitrogen and heating. The recently calculated dissociation cross sections of N2 are used in the present model (Tully and Johnson 2002). The incident flux of slowed magnetospheric N+ ions and pick-up C2H5+ ions is estimated from the work of Brecht et al. (2000). These ions, which have energies less than 1.2 keV, were shown to be more efficient in ejecting material from Titan's atmosphere than the non-deflected co-rotating ions used earlier (Lammer et al. 1993). The loss rates are comparable or larger than those produced by photo-dissociation. Exobse heating rates are given and the loss rates of N and N2 are then used as a source of nitrogen for the Titan neutral torus. If atmospheric sputtering is important this torus will contain both atomic and molecular nitrogen and, therefore, will provide a distributed source of both atomic and molecular nitrogen ions that will be readily detected by Cassini (Smith et al. 2004) Acknowledgment: This work is supported by NASA's Planetary Atmospheres Program and by the CAPS-Cassini Instrument. Brecht, S.H., J.G. Luhmann, and D.J. Larson, J. Geophys. Res., 105, 13119, 2000. Lammer, H., and S.J. Bauer,. Planet. Space Sci., 41, 657, 1993. Shematovich, V.I.,et al, J. Geophys. Res., 108, 5086, 10.1029/2003JE002096, 2003. Michael, M. et al., submitted, Icarus, 2004. Smith, H.T., et al., Titan Aeronomy Workshop, Paris, January 7-9, 2004. Tully, C., R.E. Johnson, J. Chem. Phys. 117, 6556

  17. PICASSO-SLP: a Langmuir probe instrument for monitoring the upper ionosphere on board a pico-satellite

    Science.gov (United States)

    Ranvier, Sylvain; Anciaux, Michel; Cardoen, Pepijn; Gamby, Emmanuel; Bonnewijn, Sabrina; De Keyser, Johan; Echim, Marius; Pieroux, Didier

    2016-04-01

    A novel Langmuir probe instrument, which will fly on board the Pico-Satellite for Atmospheric and Space Science Observations (PICASSO), is under development at the Royal Belgian Institute for Space Aeronomy. PICASSO, an ESA in-orbit demonstrator, is a triple unit CubeSat of dimensions 340.5x100x100 mm. The sweeping Langmuir probe (SLP) instrument, which includes four thin cylindrical probes whose electrical potential is swept, is designed to measure both plasma density and electron temperature at an altitude varying from about 400 km up to 700 km from a high inclination orbit. Therefore, the plasma density is expected to fluctuate over a wide range, from about 1e8/m³ at high latitude and high altitude up to several times 1e12/m³ at low/mid latitude and low altitude. The electron temperature is expected to lie between approximately 1.000 K and 10.000 K. Given the high inclination of the orbit, the SLP instrument will allow a global monitoring of the ionosphere with a maximum spatial resolution of the order of 150 m for the electron density and temperature, and up to a few meters for electron density only. The main goals are to study 1) the ionosphere-plasmasphere coupling, 2) the subauroral ionosphere and corresponding magnetospheric features, 3) auroral structures, 4) polar caps, 5) for the density, the multi-scale behaviour, spectral properties and turbulence of processes typical for the auroral regions, and 6) ionospheric dynamics via coordinated observations with EISCAT's heating radar. Along the orbit, the Debye length is expected to vary from a few millimetres up to a few meters. Due to the tight constraints in terms of mass and volume inherent to pico-satellites, the use of long booms, which would guarantee that the probes are outside the sheath of the spacecraft (several Debye lengths away), is not possible. Consequently, the probes might be in the sheath of the spacecraft in polar regions. Extensive modelling and simulations of the sheath effects on the

  18. [Not Available].

    Science.gov (United States)

    1996-10-18

    . Johnson, G. S. Orton, R. A. West, Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA. D. Simonelli, J. Veverka, P. J. Gierasch, D. Banfield, M. Bell, J. A. Burns, P. Thomas, Department of Astronomy, Cornell University, Ithaca, NY 14853, USA. M. H. Carr, U.S. Geological Survey, Menlo Park, CA 94025, USA. M. E. Davies, RAND, Santa Monica, CA 90406, USA. C. R. Chapman, Southwest Research Institute, Boulder, CO 80302, USA. C. Anger, ITTRES Ltd, Calgary, Alberta TIY 5Z6, Canada. G. Neukum, Institute for Planetary Exploration, Deutsche Forschunganstalt für Luft und Raumfahrt, Berlin, Germany. C. B. Pilcher, National Aeronautical and Space Administration, Washington, DC 20546, USA. R. F. Beebe, Department of Astronomy, New Mexico State University, Las Cruces, NM 88003, USA. F. Fanale, Institute for Geophysics, University of Hawaii, Honolulu, HI 96822, USA. W. Ip, Max Planck Institute für Aeronomie, Lindau, Germany. D. Morrison and J. Moore, NASA Ames Research Center, Moffett Field, CA 94035, USA. (*) To whom correspondence should be addressed. E-mail: belton@noao.edu. PMID:17813508

  19. The micrometeoric input in the upper atmosphere. A comparison between model predictions and HPLA and meteor radars observations and AIM-CDE dust detections

    Science.gov (United States)

    Janches, Diego; Sparks, Jonathan; Johnson, Kyle; Poppe, Andrew; James, David; Fentzke, Jonathan; Palo, Scott; Horanyi, Mihaly

    particles are mostly characterized by very high geocentric speeds (˜55 km/sec) since they are in retrograde orbits. The reminding 30 to 40% of meteoroids entering the atmosphere originate mostly from the Helion and Ant-Helion source, as well as the Toroidal sources. We further validate the modeled results using trail observations from a meteor radar operating at the South Pole. The results of the model are in excellent agreement with observed diurnal curves obtained at different seasons and locations using measurements from both types of radars. Based on these results, we calculate the micrometeor global, diurnal and seasonal input in the upper atmosphere. Finally, we attempt to extend our model to interpret preliminary results from measurements using the dust detector (CDE) on board of the Aeronomy of Ice in the Mesosphere (AIM) satellite.

  20. Plasma-induced Escape and Alterations of Planetary Atmospheres

    Science.gov (United States)

    Johnson, R. E.; Tucker, O. J.; Ewrin, J.; Cassidy, T. A.; Leblanc, F.

    2009-12-01

    .1029/2007JE003032 (2008) Johnson, R.E. Plasma-induced Sputtering of an Atmosphere. in Space Science Rev. 69, 215-253 (1994). Johnson, R.E., The Magnetospheric Plasma-Driven Evolution of Satellite Atmospheres, Astrophys. J. 609: L99-L102 (2004). Johnson, R.E., M.R. Combi, J.L. Fox, W-H. Ip, F. Leblanc, M.A. McGrath, V.I. Shematovich, D.F. Strobel, J.H. Waite Jr, Exospheres and Atmospheric Escape, Chapter in Comparative Aeronomy, Ed. A. Nagy, Space Sci. Rev. 139: 355-397, DOI 10.1007/s11214-008-9415-3 (2008) Johnson, R.E., Sputtering and heating of Titan's upper atmosphere, Phil. Trans. R. Soc. A 367, 753-771, doi:10.1098/rsta.2008.0244 (2009) Johnson, R.E., O.J. Tucker, M. Michael, E.C. Sittler, H.T. Smith, D.T. Young, and J.H. Waite, Mass Loss Processes in Titan's Upper Atmosphere, Springer-Verlag in press (2009) Strobel, D. F. Titan's hydrodynamically escaping atmosphere. Icarus 193, 588—594 (2008)

  1. Obituary: Tor Hagfors, 1930-2007

    Science.gov (United States)

    Aksnes, Kaare

    2007-12-01

    Association (EISCAT) and was in charge of the construction of its radar facilities in Scandinavia. In 1982 Tor was back in USA as Director of the National Astronomy and Ionosphere Center (NAIC), which manages the Arecibo Observatory. At the same time he was Professor of both Astronomy and Electrical Engineering at Cornell University in Ithaca, New York. In 1992 Hagfors accepted a call as Director of the Max-Planck Institut für Aeronomie in Lindau, Germany, where he remained until his retirement in 1998. During this period he was also Adjunct Professor at the Institute of Theoretical Astrophysics, University of Oslo, where he helped to start research projects in space research. The University of Tromsö, Norway; University of Nagoya, Japan; and University of Lancaster, UK, also benefited from visits by Tor as a Guest Professor. Hagfors was widely valued as a member of many national and international scientific committees and unions, e. g., as head of a committee on space research for the Norwegian Research Council. He received many honors, notably the Van der Pol Gold Medal (1987), a Senior Humboldt Fellowship (1989), Membership in the Norwegian Academy of Science (1995), Extraordinary Membership in the Royal Astronomical Society (1998), the Sir Granville Beynon Medal (2002), a Doctorate Honoris Causa from the University of Oulu (2002), and a Honorary Doctorate from the University of Tromsö (2003). Tor Hagfors had very wide interests; he was a brilliant researcher who published around 170 scientific papers. His many achievements in radio astronomy, in addition to what is already mentioned, included determination of the dielectric constant of the Moon's surface, radar mapping of the surfaces of Venus and of rapidly rotating planetary bodies, scattering studies of the surfaces of the Galilean satellites and of the interiors of comets and asteroids by radio sounding, and lastly the search for water on Mars by means of Mars Express data. He had a profound knowledge of not only

  2. IGRF-11描述的2005-2010年中国地区地磁长期变化及其误差分析%Geomagnetic secular variation in China during 2005-2010 described by IGRF-11 and its error analysis

    Institute of Scientific and Technical Information of China (English)

    陈斌; 顾左文; 高金田; 袁洁浩; 狄传芝

    2012-01-01

    The eleventh generation International Geomagnetic Reference Field (IGRF-11) was issued in December 2009 by the International Association of Geomagnetism and Aeronomy (IAGA). The IGRF-11 is the latest and comparatively precise IGRF. According to the IGRF-11 model, the geomagnetic secular variation (SVc) in China during 2005-2010 was calculated. The SVC and the geomagnetic secular variation (SVO) obtained from the geomagnetic data of practical observations in China are basically consistent, but there is obvious difference. The SVo and SVcat 34 observatories in China were analyzed and compared; the differences between the SVO and SVC and the mean square roots σ were obtained. The mean square roots σ are 0. 35 '/a and 0. 53 '/a for geomagnetic declination and inclination respectively; and the σ are 5. 12 nT/a, 8. 91 nT/a, 8. 89 nT/a, 3. 27 nT/a and 3. 59 nT/a for geomagnetic total intensity, horizontal component, northern component, eastern component and vertical component respectively. The reasons for the error of the geomagnetic secular variation in China during 2005-2010 described by the IGRF-11 are the regional and local magnetic anomalies in China, no external source field for the IGRF and the truncation order of the IGRF, non-homogeneous distribution of the geomagnetic observatories, stations and sites in the world, the errors of geomagnetic observations etc The China geomagnetic model (CGM) should be used in practical application, because the CGM is better than the IGRF and can describe the geomagnetic field and its secular variation in China with comparative precision.%第11代国际地磁参考场(IGRF-11)是国际地磁学与高空物理学联合会(IAGA)于2009年12月提出的最新与比较准确的IGRF.根据IGRF-11模型,计算了2005-2010年中国地区地磁长期变化(SVc).IGRF-11所描述的2005-2010年中国地区地磁长期变化与实际观测的地磁长期变化(SVo)是基本一致的,但亦有明显差异.分析比较了在中国地区34

  3. Orbiting observatory SOHO finds source of high-speed "wind" blowing from the Sun

    Science.gov (United States)

    1999-02-01

    ranging from 30,000 km/h at the surface to over 3 million km/h, the solar wind "grows" much faster than grass". "Looking at the spot where the solar wind actually appears is extremely important", says co-author Dr. Philippe Lemaire of the Institut d'Astrophysique Spatiale in Orsay, France. The Solar Ultraviolet Measurements of Emitted Radiation (SUMER) spectrometer on SOHO detected the solar wind by observing the ultraviolet spectrum over a large area of the solar north polar region. The SUMER instrument was built under the leadership of Dr. Klaus Wilhelm at the Max-Planck-Institut für Aeronomie in Lindau, Germany, with key contributions from the Institut d'Astrophysique Spatiale in Orsay, France, the NASA Goddard Space Flight Center in Greenbelt, Maryland, and the University of California at Berkeley, with financial support from German, French, US and Swiss national agencies. "Identification of the detailed structure of the source region of the fast solar wind is an important step in solving the solar wind acceleration problem. We can now focus our attention on the plasma conditions and the dynamic processes seen in the corners of the magnetic field structures", says Dr. Wilhelm, also co-author of the Science paper. A spectrum results from the separation of light into its component colours, which correspond to different wavelengths. Blue light has a shorter wavelength and is more energetic than red. A spectrum is similar to what is seen when a prism separates white light into a rainbow of distinct colours. By analysing light this way, astronomers learn a great deal about the object emitting the light, such as its temperature, chemical composition, and motion. The ultraviolet light observed by SUMER is actually invisible to the human eye and cannot penetrate the Earth's atmosphere. The hot gas in the solar wind source region emits light at certain ultraviolet wavelengths. When the hot gas flows towards Earth, as it does in the solar wind, the wavelengths of the

  4. Once a myth, now an object of study - How the perception of comets has changed over the centuries

    Science.gov (United States)

    2004-02-01

    In February 2004, Rosetta will be setting off on its long journey through our solar system to meet up with Comet Churyumov-Gerasimenko. It will take the European Space Agency (ESA) space probe ten years to reach its destination. The comet, which moves in an elliptical orbit around the Sun, will at rendezvous be some 675 million kilometres from the Sun, near the point in its orbit farthest from the Sun. The meeting point was not chosen at random: at this point the comet is still barely active, it is still in fact a frozen lump of ice and interplanetary dust, in all probability the matter from which our solar system emerged four and a half billion years ago. Rosetta’s job is to find out more about these strange bodies that travel through our solar system. As it moves on, the comet will begin to change. As it approaches the Sun, it will - like all comets - become active: in the warmth of the Sun’s rays, the ices evaporate, tearing small dust particles from the surface. This produces the comet head (the coma) and tail. Only these two phenomena are visible from Earth. The comet nucleus itself is far too tiny - Churyumov-Gerasimenko measures about 4 kilometres across - to be viewed from Earth. As Dr Uwe Keller of the Max Planck Institute for Aeronomy in Kaltenburg-Lindau, the scientist responsible for the Osiris camera carried by Rosetta, explains, “Formation of the coma and tail during solar flyby skims several metres of matter off the comet’s surface. In the case of a small comet like Churyumov-Gerasimenko, the shrinkage is a good 1% each time round.” As it flies past the Sun every 6.6 years it can look forward to a short future, especially on a cosmic timescale. Comets - a mystical view Visible cometary phenomena have fascinated human beings from time immemorial - and frightened them too. Even today mystical explanations prevail among some of the Earth’s peoples. The Andaman islanders, a primitive people living in the Gulf of Bengal, see comets as burning

  5. Preface

    Directory of Open Access Journals (Sweden)

    Baldev Arora

    2009-06-01

    Full Text Available Earth is a complex dynamic system and study of the geomagnetic field can provide
    insight to the dynamic processes operative in the outer core where the main field is
    produced by a geo-dynamo mechanism. By contrast the study of transient geomagnetic
    variations is an important tool for studying the complex solar wind-magnetosphere-
    ionosphere coupling. In addition the currents induced by the time varying external
    current system allow us to image the crust and the upper mantle in terms of
    electric conductivity. Lack of measurements and collection of geomagnetic data from
    certain strategic locations restricts the development of high quality models of main
    geomagnetic field as well as the current systems responsible for transient geomagnetic
    variations. Division V of the International Association of Geomagnetic Aeronomy
    (IAGA jointly with the Interdivisional Commission for Developing Countries organized
    a special symposium «Geomagnetic Measurements in Remote Regions» at General
    Assembly of IUGG held at Perugia (Italy during July 2-12, 2007. Papers were
    presented on data base numerical simulations identifying strategic gaps in the existing
    observatory network where new measurements of geomagnetic field could improve
    upon existing geomagnetic reference models. Special focus was on describing the
    novel design of equipment, modes of data collection and dissemination from remote
    regions. During the symposium, 21 presentations were presented and this issue of
    Annals of Geophysics compiles a selection of papers.
    It is significant that each paper in this special issue is multi-authored by several
    institutions and countries. This emphasizes the importance of worldwide collaboration
    when obtaining and analyzing data from geophysical observations in remote regions.
    With current technology magnetic observatories still require people to take

  6. Europe goes to Mars - preparations are well under way

    Science.gov (United States)

    2001-04-01

    -mail: psri@open.ac.uk HRSC (High/Super Resolution Stereo Camera), Gerhard Neukum, DLR, Institut für Planetenerkundung, Berlin, Germany, tel. +49 30 67055 300, fax. +49 30 67055 303, e-mail: gerhard.neukum@dlr.de MaRS (Radio Science Experiment), Martin Pätzold, University of Cologne, Germany, tel. +49 221 4703385, fax. +49 221 4705198, e-mail: paetzold@geo.uni-koeln.de MARSIS (Subsurface Sounding Radar/Altimeter), Giovanni Picardi, University of Rome, Italy, tel. +39 06 44585455, fax. +39 06 4873300, e-mail: picar@infocom.ing.uniroma1.it OMEGA (IR Mineralogical Mapping Spectrometer), Jean-Pierre Bibring, Institut d'Astrophysique Spatiale, Orsay, France, tel. +33 1 69858686, fax. +33 1 69858675, e-mail: bibring@ias.u-psud.fr PFS (Planetary Fourier Spectrometer), Vittorio Formisano, Istituto Fisica Spazio Interplanetario, Rome, Italy, tel. +39 6 49934362, fax. +39 6 49934383, e-mail: formisan@nike.ifsi.rm.cnr.it SPICAM (UV and IR Atmospheric Spectrometer), Jean-Loup Bertaux, Service d'Aéronomie, Verrières-le-Buisson, France, tel. +33 1 64474251, fax. +33 1 6920299, e-mail: jean-loup.bertaux@aerov.jussieu.fr. Additional contact: Christian Muller, Belgian Institute for Space Aeronomy. B.USOC earth observations coordination, Avenue Circulaire, 3, B-1180 Brussels, Belgium, tel. +32-2-3730372, fax: +32-2-3748423, e- mail: Christian.Muller@oma.be

  7. ESA's Rosetta mission and the puzzles that Hale-Bopp left behind

    Science.gov (United States)

    1997-04-01

    the origin of life on the Earth. The comet specialist Uwe Keller of the Max-Planck Institut fur Aeronomie, Germany, is one of the Giotto veterans who has helped with the planning of Rosetta. He was in charge of Giotto's camera. "Rosetta is the mission we are all waiting for," Dr Keller comments. "After I spent six years analysing our images of the Halley nucleus, I say that basic scientific assumptions about the nature of comets are still contradictory. We shall settle the arguments only by the close, prolonged inspection that Rosetta will make possible." Engineering the Rosetta mission To build up the speed needed to adopt the same orbit around the Sun as Comet Wirtanen, Rosetta must steal energy of motion from the planets, in a swingby of Mars and two swingbys of the Earth. During its far-flung manoeuvres in pursuit of the comet, Rosetta will inspect the asteroids Mimistrobell and Rodari at close quarters. When Rosetta is far from the Earth, or on the wrong side of the Sun, communication will be difficult. The spacecraft will therefore have a high degree of robotic self-reliance. It will also be capable of hibernating for more than two years without attention -- a technique devised by ESA for the later stages of the Giotto mission. Rosetta will rely on solar power, even when more than five times further than the Earth from the Sun. Special low-intensity solar cells are under development for Rosetta. Conditions in this farthest phase of Rosetta's voyage will be very chilly, but ESA's engineers are satisfied that the temperatures inside the spacecraft can be kept within limits by black paint, multilayer insulation and electric heaters. Despite its originality and sophistication, Rosetta will be just a flying box with solar arrays like wings, looking rather like a telecommunications satellite. "Keep it simple," is the motto of John Credland, ESA's project manager for Rosetta. "Simplicity brings reliability," he explains, "and that is my overriding concern for the

  8. The Sun as you never saw it before

    Science.gov (United States)

    1997-02-01

    went into creating LASCO and SOHO, and leave aside the many points of scientific importance in the images, I am happy to marvel at a new impression of the busy star that gives us life, and which affects our environment in many ways that we are only now beginning to understand." Transatlantic cooperation The Solar and Heliospheric Observatory SOHO is a project of international cooperation between ESA and NASA. ESA and the European aerospace industry built the spacecraft, and NASA launched it on 2 December 1995. Operating 1,500,000 kilometres out on the sunward side of the Earth, near the position called Lagrangian point L1, SOHO has an uninterrupted view of the Sun from an undisturbed vantage point, and a precision of pointing which makes delicate observations possible. SOHO carries 12 sets of instruments provided by scientific teams, each led by a European or an American principal investigator. They study the solar interior by helioseismology, the solar atmosphere seen by ultraviolet and visible light, and the solar wind and energetic particles. There is much transatlantic collaboration within the various teams. Besides the Naval Research Laboratory in Washington, LASCO involves the Max-Planck-Institüt für Aeronomie at Lindau (Germany), the Unversity of Birmingham (England) and Laboratoire d'Astronomie Spatiale at Marseille (France). Sharing LASCO's electronic systems, and many operations and analyses, is SOHO's extreme ultraviolet imager EIT. This is the responsibility of a team led from Orsay (France) and it observes activity in the Sun's hot atmosphere related to the wider events seen by LASCO. Roger Bonnet, who presides over the multinational effort as ESA's Director of Science, shares the enthusiasm for the Christmas movie. "For the first time we see the Sun clearly among the stars, thanks to SOHO and LASCO," Bonnet comments. "Now when we say that the Sun is a typical star, and a key to understanding the whole Universe, that is no longer a theoretical statement