WorldWideScience

Sample records for aeronomy

  1. Dissociative recombination in aeronomy

    Science.gov (United States)

    Fox, J. L.

    1989-01-01

    The importance of dissociative recombination in planetary aeronomy is summarized, and two examples are discussed. The first is the role of dissociative recombination of N2(+) in the escape of nitrogen from Mars. A previous model is updated to reflect new experimental data on the electronic states of N produced in this process. Second, the intensity of the atomic oxygen green line on the nightside of Venus is modeled. Use is made of theoretical rate coefficients for production of O (1S) in dissociative recombination from different vibrational levels of O2(+).

  2. Outstanding problems in Mars aeronomy

    Science.gov (United States)

    Luhmann, J. G.

    1995-01-01

    Although the Phobos-2 spacecraft recently obtained important results relevant to some of the major remaining questions in Mars aeronomy, much remains to be done. In particular, not since the Viking Landers have we made in-situ measurements of aeronomical quantities such as atmospheric and ionospheric densities and temperatures below 400 km altitude. We have never made magnetic field measurements at these altitudes. Without such measurements we cannot unambiguously resolve arguments concerning issues such as the significance of the planetary magnetic field in the solar wind interaction, or understand the atmospheric cycle that leads to escape to space. With the trio of future orbiters including Mars Observer, Mars-94, and Planet-B we should see a veritable explosion of new knowledge, but some gaps in aeronomical science coverage will still remain. This paper briefly reviews some of the major unsolved problems in Mars aeronomy, and points out which are expected to remain outstanding after this flotilla of missions.

  3. Aeronomy

    Science.gov (United States)

    Atreya, S. K.

    1984-01-01

    From the known composition (H2, CH4, C2H2(?) at Uranus, and H2, CH4, C2H6 at Neptune) and the inversion and photolysis region temperatures, reasonable theoretical models for the upper atmospheric distribution of the neutral and ionospheric species are constructed on the basis of the expected physical and chemical processes. The models indicate that C2H2 would condense over an extensive height range of Uranus. The extent of the haze is expected to be smaller and deeper in the polar region. Some ethane is also expected to condense, mostly in the vicinity of the temperature inversion. The behavior of the acetylene condensation with latitude and time appears to be consistent with its apparent abundance variation (detected by IUE), and the brightening of Uranus observed in ground based imaging. Neptune's polar region, on the other hand is expected to be more hazy or cloudy than the equatorial region.

  4. 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.

  5. An aeronomy mission to investigate the entry and orbiter environment of Mars

    Science.gov (United States)

    Brace, Larry H.

    1989-01-01

    The need for an aeronomy mission to Mars as a precursor to a manned Mars mission is discussed. The upper atmosphere and radiation environment of Mars are reviewed, focusing on the implications of the Martian atmosphere for a manned mission. Plans for an aeronomy mission to Mars are described, including the Mars Aeronomy Observer and the Earth/Mars Aeronomy Orbiter.

  6. Aeronomy of Ice in the Mesosphere (AIM)

    Science.gov (United States)

    2003-01-01

    The overall goal of the Aeronomy of Ice in the Mesosphere (AIM) experiment is to resolve why Polar Mesospheric Clouds form and why they vary. By measuring PMCs and the thermal, chemical and dynamical environment in which they form, we will quanti@ the connection between these clouds and the meteorology of the polar mesosphere. In the end, this will provide the basis for study of long-term variability in the mesospheric climate and its relationship to global change. The results of AIM will be a rigorous validation of predictive models that can reliably use past PMC changes and present trends as indicators of global change. The AIM goal will be achieved by measuring PMC extinction, brightness, spatial distribution, particle size distributions, gravity wave activity, dust influx to the atmosphere and precise, vertical profile measurements of temperature, H20, C&, 0 3 , C02, NO. and aerosols. These data can only be obtained by a complement of instruments on an orbiting spacecraft (S/C).

  7. 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

  8. A Perspective of the Science and Mission Challenges in Aeronomy

    Science.gov (United States)

    Spann, James F.

    2010-01-01

    There are significant fundamental problems for which aeronomy can provide solutions and a critical role in applied science and space weather that only aeronomy can address. Examples of unresolved problems include the interaction of neutral and charged, the role of mass and energy transfer across Earth's interface with space, and the predictability of ionospheric density and composition variability. These and other problems impact the productivity of space assets and thus have a tangible applied dimension. This talk will explore open science problems and barriers to potential mission solutions in an era of constrained resources.

  9. JOVE NASA-FIT program: Microgravity and aeronomy projects

    Science.gov (United States)

    Patterson, James D.; Mantovani, James G.; Rassoul, Hamid K.

    1994-01-01

    This semi-annual status report is divided into two sections: Scanning Tunneling Microscopy Lab and Aeronomy Lab. The Scanning Tunneling Microscopy (STM) research involves studying solar cell materials using the STM built at Florida Tech using a portion of our initial Jove equipment funding. One result of the participation in the FSEC project will be to design and build an STM system which is portable. This could serve as a prototype STM system which might be used on the Space Shuttle during a Spacelab mission, or onboard the proposed Space Station. The scanning tunneling microscope is only able to image the surface structure of electrically conductive crystals; by building an atomic force microscope (AFM) the surface structure of any sample, regardless of its conductivity, will be able to be imaged. With regards to the Aeronomy Lab, a total of four different mesospheric oxygen emission codes were created to calculate the intensity along the line of sight of the shuttle observations for 2972A, Herzberg I, Herzberg II, and Chamberlain bands. The thermosphere-ionosphere coupling project was completed with two major accomplishments: collection of 500 data points on modulation of neutral wind with geophysical variables, and establishment of constraints on behavior of the height of the ionosphere as a result of interaction between geophysical and geometrical factors. The magnetotail plasma project has been centered around familiarization with the subject in the form of a literature search and preprocessing of IMP-8 data.

  10. 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.

  11. Morrow, Reiff, Receive 2013 Space Physics and Aeronomy Richard Carrington Awards: Citation for Cherilynn Ann Morrow

    Science.gov (United States)

    Lopez, Ramon

    2014-08-01

    The Space Physics and Aeronomy Richard Carrington (SPARC) Education and Public Outreach Award for Cherilynn Morrow recognizes years of pioneering work on behalf of the space science community in the area of education and public outreach (E/PO).

  12. Mars Aeronomy Explorer (MAX): Study Employing Distributed Micro-Spacecraft

    Science.gov (United States)

    Shotwell, Robert F.; Gray, Andrew A.; Illsley, Peter M.; Johnson, M.; Sherwood, Robert L.; Vozoff, M.; Ziemer, John K.

    2005-01-01

    An overview of a Mars Aeronomy Explorer (MAX) mission design study performed at NASA's Jet Propulsion Laboratory is presented herein. The mission design consists of ten micro-spacecraft orbiters launched on a Delta IV to Mars polar orbit to determine the spatial, diurnal and seasonal variation of the constituents of the Martian upper atmosphere and ionosphere over the course of one Martian year. The spacecraft are designed to allow penetration of the upper atmosphere to at least 90 km. This property coupled with orbit precession will yield knowledge of the nature of the solar wind interaction with Mars, the influence of the Mars crustal magnetic field on ionospheric processes, and the measurement of present thermal and nonthermal escape rates of atmospheric constituents. The mission design incorporates alternative design paradigms that are more appropriate for-and in some cases motivate-distributed micro-spacecraft. These design paradigms are not defined by a simple set of rules, but rather a way of thinking about the function of instruments, mission reliability/risk, and cost in a systemic framework.

  13. 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

  14. Living With a Star, the Geospace Mission Definition Team and Aeronomy

    Science.gov (United States)

    Kintner, Paul M., Jr.; Meier, R. R.; Spann, Jim; Whitaker, Ann F. (Technical Monitor)

    2001-01-01

    To gain an understanding of the Sun-Earth system, including how and why the sun varies, how the earth responds, and the impacts on humanity, research is needed that has a integrated and systematic approach. The Living With a Star (LWS) program represents an important element in this regard both to continued progress in space science in general and in Aeronomy in particular. A fundamental question in Aeronomy is how the variable sun affects the ionosphere, thermosphere, and mesosphere. The LWS program focuses on those areas of scientific understanding that promote progress in areas that have human impact and can be investigated with space borne instruments. The Geospace Mission Definition Team is charged with investigating the science priorities identified by the LWS Science Architecture Team and developing an approach to making the necessary measurements in concert with other missions and programs. An important aspect of this approach is that all LWS measurement programs are operating simultaneously for several years. We will review some of the areas that the LWS SAT have emphasized in Aeronomy, including understanding the effects of solar variability on ionospheric density and irregularities, the effects of solar variability on the mass density of the atmosphere at LEO altitudes, and the effects of solar variability on near-surface temperatures and on ozone distribution.

  15. Recommendation for a set of solar EUV lines to be monitored for aeronomy applications

    OpenAIRE

    J. Lilensten; T. Dudok de Wit; Amblard, P. -O.; Aboudarham, J.; Auchère, F.; Kretzschmar, M

    2007-01-01

    International audience; In two recent studies, Dudok de Wit et al. (2005) and Kretzschmar et al. (2006) have shown that the solar Ultra-Violet spectrum between 25 and 195 nm can be reconstructed from the observation of a set of 6 to 10 carefully chosen spectral lines. The best set of lines, however, is application dependent. In this study, we demonstrate that a good candidate for aeronomy applications consists of the following 6 lines: H I at 102.572 nm, C III at 97.702 nm, O V at 62.973 nm, ...

  16. Optical aeronomy

    Science.gov (United States)

    Solomon, Stanley C.

    1991-01-01

    Optical measurements of thermospheric and ionospheric processes and their interpretation are reviewed and the chemical reactions and their effects on emissions are discussed. Also included are the phenomena which excite the airglow and aurora, i.e., the solar UV/EUV flux and auroral particle precipitation. Consideration is given to solar flux, atomic emissions, molecular emissions, hydrogen geocorona, and molecular oxygen and the green line nightglow.

  17. 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.

  18. Recommendation for a set of solar EUV lines to be monitored for aeronomy applications

    Directory of Open Access Journals (Sweden)

    J. Lilensten

    2007-06-01

    Full Text Available In two recent studies, Dudok de Wit et al. (2005 and Kretzschmar et al. (2006 have shown that the solar Ultra-Violet spectrum between 25 and 195 nm can be reconstructed from the observation of a set of 6 to 10 carefully chosen spectral lines. The best set of lines, however, is application dependent. In this study, we demonstrate that a good candidate for aeronomy applications consists of the following 6 lines: H I at 102.572 nm, C III at 97.702 nm, O V at 62.973 nm, He I at 58.433 nm, Fe XV at 28.415 nm and He II at 30.378 nm. The TRANSCAR model is used to quantify the impact of each individual line on the density, temperature and velocity profiles. Using a multidimensional scaling technique, we show how to select from this the best set of lines. Although this selection is motivated by the specification of the ionosphere, our set of lines is also found to be appropriate for reconstructing the variability of the solar spectrum between 25 and 195 nm.

  19. Fabry-Perot CCD annular-summing spectroscopy: study and implementation for aeronomy applications.

    Science.gov (United States)

    Coakley, M M; Roesler, F L; Reynolds, R J; Nossal, S

    1996-11-20

    The technique of Fabry-Perot CCD annular-summing spectroscopy, with particular emphasis on applications in aeronomy, is discussed. Parameter choices for optimizing performance by the use of a standard format CCD array are detailed. Spectral calibration methods, techniques for determining the ring pattern center, and effects imposed by limited radial resolution caused by superpixel size, variable by on-chip binning, are demonstrated. The technique is carefully evaluated experimentally relative to the conventional scanning Fabry-Perot that uses a photomultiplier detector. We evaluate three extreme examples typical of aeronomical spectroscopy using calculated signal-to-noise ratios. Predicted sensitivity gains of 10-30 are typical. Of the cases considered, the largest savings in integration time are estimated for the day sky thermospheric O(1)D case, in which the bright sky background dominates the CCD read noise. For profile measurements of faint night sky emission lines, such as exospheric hydrogen Balmer-α, long integration times are required to achieve useful signal-to-noise ratios. In such cases, CCD read noise is largely overcome. Predictions of a factor of 10-15 savings in integration time for night sky Balmer-α observations are supported by field tests. Bright, isolated night sky lines such as thermospheric O(1)D require shorter integration times, and more modest gains dependent on signal level are predicted. For such cases it appears from estimate results that the Fabry-Perot CCD annular-summing technique with a conventional rectangular format may be outperformed by a factor of 2-5 by special CCD formats or by unusual optical coupling configurations that reduce the importance of read noise, based on the ideal transmission for any additional optics used in these configurations.

  20. Effects of X-ray flares on the aeronomy of Mars: Simultaneous measurements of ionospheric effects of X-ray flares on Earth and Mars

    Science.gov (United States)

    Haider, Syed A.; Machado Santos, Angela; Abdu, Mangalathayil A.; Batista, Inez S.; Shah, Siddhi Y.; Thirupathaiah, P.

    2016-07-01

    MIRI: Validation and Testing Requirements We have studied X-ray aeronomy in the ionospheric E region of Mars during six X-ray flares that occurred on 28 March and 6 April, 2001; 17,18 March and 21 April, 2003 and 19 February, 2005 respectively. These flares were responded by the corresponding electron density profiles of Mars Global Surveyor (MGS). The time series of photoionization rate, photoelectron impact ionization rate, photoelectron flux, ion density, electron density and total Electron Content (TEC) are predicted for each flare day. The estimated production rate, flux and densities are increased by 1-2 orders of magnitude due to effects of these flares in the E region ionosphere of Mars. The normalized estimated TEC are compared with the normalized measured TEC of MGS profiles. At the peak flare time the normalized estimated and normalized measured TEC were enhanced by a factor of 5-10 and 2 respectively. The effects of these flares were also registered in the D region equatorial ionosphere of Earth at Fortaleza observatory. The flares of 6 April, 2001, 17 March and 21 April, 2003 also produced electron density enhancement in the E region ionosphere of Earth at College AK and Cachoeira Paulista observatories. The minimum frequency fmin, recorded in ionogram, increased by 100% (due to D region absorption) while the foE increased by 20%, in the Earth's ionosphere.

  1. Planetary Aeronomy and Related Studies

    Science.gov (United States)

    Hunten, D. M.; Bougher, S. W.; Sprague, A. L.

    1997-01-01

    Mercury atmosphere - Sprague and Hunten, in collaboration with Katharina Lodders of Washington University, proposed, mainly on cosmochemical grounds, that S atoms are an important constituent of the atmosphere (30 times more abundant than sodium). This paper has appeared in Icarus. We also suggest that condensed sulfur is an excellent candidate for the radar-bright polar caps, more plausible than water ice because the latter is only barely stable even in permanently-shadowed craters. The best prospect for detection of the vapor is through its resonance lines, a triplet near 1814 A. Mercury is too close to the Sun to be observed by any existing space telescope, but there is some prospect that the search could be made from a Shuttle-based spectrograph such as Lyle Broadfoot's USTAR. Sprague and Hunten have completed an elaborate data analysis of over 100 measurements of the Na D lines, obtained with the 61-inch telescope and our echelle spectrograph. Full account has been taken of the radiative-transfer problem that arises because the Na atmosphere is not optically thin. The output of this code is used in another program that makes an elaborate inverse interpolation in two angles and optical depth and computes the effect of the seeing (always bad for Mercury). The seeing is determined by fitting cuts across a computed image to part of the spectrum adjacent to the sodium lines, and typically ranges from slightly less than 4 arcsec to worse than 6 (diameter at l/e of a Gaussian). The final result is a list of Na abundances, with some information on spatial distribution. One particularly interesting result of further analysis is a strong abundance maximum in the morning relative to the afternoon, confirming an earlier result for potassium, based on much fewer measurements. The analysis are completed during the extension of the present grant. This work depends heavily on the Hapke parameters used to estimate the reflectance of Mercury's surface. The paper by Domingue et al. examines the credibility of the available parameters, which are derived from disk-unresolved photometry, and concludes that errors in the derived Na abundances could be as great as 30%.

  2. 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

  3. The General Assembly of International Association of Geomagnetism and Aeronomy-Inter- national Association of Seismology and Physics of the Earth's Interior Held in Hanoi%国际地磁学与高空物理学协会和国际地震学与地球内部物理学协会学术大会在河内举行

    Institute of Scientific and Technical Information of China (English)

    中国地震局地球物理研究所外事办公室

    2001-01-01

    @@ 2001年8月20~31日,国际地磁学与高空物理学协会(International Association of Geomagnetism and Aeronomy, IAGA)和国际地震学与地球内部物理学协会(International Association of Seismology and Physics of the Earth's Interior, IASPEI)联合学术大会在越南河内举行.这是IAGA和IASPEI组织的第一次联合学术大会.

  4. 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.

  5. 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.

  6. Low Latitude Aeronomy Study in Africa

    Science.gov (United States)

    2016-02-09

    was acquired and an aluminum base plate was attached to the optical dome for mounting on the top of the house for the instrument. The dome was...Preparation in Ivory Coast NCAR also worked closely with our Ivory Coast colleagues to make the necessary preparation for the site. An optical dome ...constructed a new hut to house the FPI with their funding (Figure 2). Figure 2. The hut (under construction earlier in 2015) in Korhogo Ivory

  7. 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...

  8. The Atmosphere as Laboratory: Aeronomy by Astronomy

    Science.gov (United States)

    Slanger, T. G.; Cosby, P. C.; Huestis, D. L.

    2002-01-01

    Astronomical sky spectra, which are byproducts of long-slit observations with echelle spectrographs on large telescopes, provide a unique platform for studying the optical emissions of excited molecules and atoms in the terrestrial atmosphere that can greatly extend present knowledge based on laboratory spectra. This paper summarizes some of the advances that have been made in our understanding of the lower electronic states of O2 and other species from the sky spectra and from direct observations of the Venus nightglow.

  9. Aeronomy of the current Martian atmosphere

    Science.gov (United States)

    Barth, C. A.; Stewart, A. I. F.; Bougher, S. W.; Hunten, D. M.; Bauer, S. J.; Nagy, A. F.

    1992-01-01

    The thermal structure of the Martian atmosphere, which varies diurnally, seasonally and episodically, is discussed. The atomic oxygen airglow at 1304 A is used to determine the density of atomic oxygen, and the 1216-A Lyman-alpha line is used to calculate the density of atomic hydrogen and, when coupled with the temperature measurement, the escape flux of atomic hydrogen. The most intense airglow is the IR atmospheric band of O2 at 1.27 micron that results from the photodissociation of ozone. The escape mechanism for atomic hydrogen is thermal, or Jeans, escape, while the atomic oxygen escape is caused by a nonthermal process, namely, the dissociative recombination of O2(+). The ratio of deuterium to hydrogen is enriched by a factor of 6. Three-dimensional models of the Mars thermospheric circulation show that planetary rotation has a significant effect on the wind, composition, and temperature structure.

  10. The 2010 Polar Aeronomy and Radio Science (PARS) Summer School

    Science.gov (United States)

    2011-12-30

    deployed at the NOAA Kasitsna Bay Laboratory in Homer, AK, near the town of Seldovia (denoted as “S” on the map) .... 47 Figure 39 Experiment to...Effects on GPS Jade Morton HAARP July 21 ELF/VLF Generation with HAARP Morris Cohen HAARP July 22 Students present results of their...at the NOAA Kasitsna Bay Laboratory in Homer, AK, near the town of Seldovia (denoted as “S” on the map) In Figure 38, the left panel shows ray

  11. 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.

  12. 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.

  13. Comparative aeronomy: Molecular ionospheres at Earth and Mars

    Science.gov (United States)

    Mendillo, Michael; Trovato, Jeffrey; Narvaez, Clara; Mayyasi, Majd; Moore, Luke; Vogt, Marissa F.; Fallows, Kathryn; 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 subsolar 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 photochemical-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.

  14. Rocket and laboratory studies in aeronomy and astrophysics

    Science.gov (United States)

    Feldman, P. D.

    1986-01-01

    Progress from March 1, 1986 to August 31, 1986 is covered and includes the work performed in response to a proposal entitled A Spartan Payload for Spatially Resolved Spectroscopy of Extended Faint Sources in the Extreme Ultraviolet (EUV). During this period, one rocket was launched, the reflight of the payload to observe Halley's comet on March 13, 1986. Most of the effort during this period was concentrated on detailed mechanical and electronic design of a Spartan payload and on the reduction and analysis of the data from the two Halley rocket flights and from the UVX experiment which flew on STS-61C in January 1986.

  15. 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.

  16. Electron temperature and density probe for small aeronomy satellites

    Science.gov (United States)

    Oyama, K.-I.; Hsu, Y. W.; Jiang, G. S.; Chen, W. H.; Cheng, C. Z.; Fang, H. K.; Liu, W. T.

    2015-08-01

    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 Te in low frequency mode and Ne 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 (fUHR). 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.

  17. Rocket and laboratory studies in aeronomy and astronomy

    Science.gov (United States)

    Feldman, P. D.

    1983-01-01

    Data extracted from semi-annual status reports presented include: a list of all sounding rocket launches performed under NASA sponsorship; a list of Ph.D. and M.A. degrees awarded to students who worked in these programs; a summary bibliography of all publications through 1983; the most recent list of the publications from the IUE program; a summary of instrument development supported by the Johns Hopkins sounding rocket program; and a list of faculty and post-doctoral research associates whose work was supported by this grant.

  18. 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.

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

    Science.gov (United States)

    Morrow, Cherilynn

    2014-08-01

    I am delighted to receive the SPARC award, which recognizes education and public outreach (E/PO) efforts that incorporate our community's scientific achievements while addressing authentic educational needs. No one is honored in isolation, and I owe a large debt of gratitude to many fellow pioneers, including the author of the citation above and my fellow SPARC awardee, Pat Reiff. Back in 1994, she was one of two committee members to be overtly supportive as I made the first ever E/PO presentations to the (then) NASA Space Science Advisory Committee. Today all of the recent space science decadal reports include explicit support for E/PO programs integrated within NASA and National Science Foundation research missions.

  1. NOAA Aeronomy Laboratory long-path OH experiment, Fritz Peak Observatory, Colorado

    Science.gov (United States)

    Mount, George H.

    1994-01-01

    Long path absorption of laser light over a 20.6 km path at Fritz Peak Observatory 17 km west of Boulder is described: elevation 2800 m, average beam height above terrain approximately 250 m, and operational since March 1991. System runs at maximum signal to noise with integration times longer than 64 seconds. Most of the data obtained to date are 15-minute averages due to the lengthy data analysis required.

  2. Precision ADCS of a spinning spacecraft for the Mars Aeronomy Explorer Mission

    Science.gov (United States)

    Mungas, Greg S.; Shotwell, Robert; Gray, Andrew

    2005-01-01

    This paper discusses a precision attitude and control technique for meeting these requirements utilizing a similar architecture that was adopted for the Laboratory of Atmospheric and Space Physics (LASP) SNOE (Student Nitrous Oxide Explorer) spinning spacecraft; SNOE has been operating with its ADCS architecture in low earth orbit (LEO) for over two years.

  3. The Aeronomy of Mars: Characterization by MAVEN of the Upper Atmosphere Reservoir That Regulates Volatile Escape

    Science.gov (United States)

    Bougher, S. W.; Cravens, T. E.; Grebowsky, J.; Luhmann, J.

    2015-12-01

    The Mars thermosphere-ionosphere-exosphere (TIE) system constitutes the atmospheric reservoir (i.e. available cold and hot planetary neutral and thermal ion species) that regulates present day escape processes from the planet. The characterization of this TIE system, including its spatial and temporal (e.g., solar cycle, seasonal, diurnal, episodic) variability is needed to determine present day escape rates. Without knowledge of the physics and chemistry creating this TIE region and driving its variations, it is not possible to constrain either the short term or long term histories of atmosphere escape from Mars. MAVEN (Mars Atmosphere and Volatile Evolution Mission) will make both in-situ and remote measurements of the state variables of the Martian TIE system. A full characterization of the thermosphere (˜100-250 km) and ionosphere (˜100-400 km) structure (and its variability) will be conducted with the collection of spacecraft in-situ measurements that systematically span most local times and latitudes, over a regular sampling of Mars seasons, and throughout the bottom half of the solar cycle. Such sampling will far surpass that available from existing spacecraft and ground-based datasets. In addition, remote measurements will provide a systematic mapping of the composition and structure of Mars neutral upper atmosphere and coronae (e.g. H, C, N, O), as well as probe lower altitudes. Such a detailed characterization is a necessary first step toward answering MAVEN's three main science questions (see Jakosky et al. 2014, this issue). This information will be used to determine present day escape rates from Mars, and provide an estimate of integrated loss to space throughout Mars history.

  4. Monochromatic imaging instrumentation for applications in aeronomy of the earth and planets

    Science.gov (United States)

    Baumgardner, Jeffrey; Flynn, Brian; Mendillo, Michael

    1992-01-01

    Monochromatic imaging instrumentation has been developed that uses narrow-band (12 A FWHP) interference filters or plane reflection gratings for 2D imaging and imaging spectrograph applications. By changing the optics in front of the filter or grating, the field of view of the instruments can be varied from 180 deg to 6 deg. In the case of the 2D monochromatic imager, the 12 mm-diameter filtered image is formed at about f/1 on the input photocathode of an intensified CCD camera (380 x 488 pixels). The sensitivities of the systems are about 50-100 R s (S/N about 2). Examples of data taken with both of these instruments include detection and mapping of Jupiter's sodium magnetonebula and stable auroral red arcs in the terrestrial ionosphere.

  5. A Revolutionary Aeronomy Concept to Explore the Coupling of the Solar-Terrestrial System

    Science.gov (United States)

    Spann, James

    2014-01-01

    The Geospace Dynamics Observatory (GDO) mission observes the near-Earth region in space called Geospace with unprecedented resolution, scale and sensitivity. At a distance of 60 Earth Radii (Re) in a near-polar circular orbit and at approximately 27-day period, GDO images the earth's full disk with: (1) a three-channel far ultraviolet imager, (2) an extreme ultraviolet imager of the plasmasphere, and (3) a spectrometer in the near to far ultraviolet range that probes any portion of the disk and simultaneously observes the limb.

  6. The International Symposium on Equatorial Aeronomy (10th) Held in Antalya, Turkey on May 17-23, 2000

    Science.gov (United States)

    2006-05-31

    Marriot et al. (1979), Reddy (1989), Somayajulu et al. (1993), Stening et al. (1996) and the references therein], the causative mechanism for its...1993)]. Marriot (1979) using Richmond’s (1973) steady-state and ’infinite counductivity model’ of the electrojet, found that the diurnal tide is the

  7. MOOSE: A Multi-Spectral Observatory Of Sensitive EMCCDs for innovative research in space physics and aeronomy

    Science.gov (United States)

    Samara, M.; Michell, R. G.; Hampton, D. L.; Trondsen, T.

    2012-12-01

    The Multi-Spectral Observatory Of Sensitive EMCCDs (MOOSE) consists of 5 imaging systems and is the result of an NSF-funded Major Research Instrumentation project. The main objective of MOOSE is to provide a resource to all members of the scientific community that have interests in imaging low-light-level phenomena, such as aurora, airglow, and meteors. Each imager consists of an Andor DU-888 Electron Multiplying CCD (EMCCD), combined with a telecentric optics section, made by Keo Scientific Ltd., with a selection of available angular fields of view. During the northern hemisphere winter the system is typically based and operated at Poker Flat Research Range in Alaska, but any or all imagers can be shipped anywhere in individual stand-alone cases. We will discuss the main components of the MOOSE project, including the imagers, optics, lenses and filters, as well as the Linux-based control software that enables remote operation. We will also discuss the calibration of the imagers along with the initial deployments and testing done. We are requesting community input regarding operational modes, such as filter and field of view combinations, frame rates, and potentially moving some imagers to other locations, either for tomography or for larger spatial coverage. In addition, given the large volume of auroral image data already available, we are encouraging collaborations for which we will freely distribute the data and any analysis tools already developed. Most significantly, initial science highlights relating to aurora, airglow and meteors will be discussed in the context of the creative and innovative ways that the MOOSE observatory can be used in order to address a new realm of science topics, previously unachievable with traditional single imager systems.

  8. 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.

  9. The Third General Scientific Assembly of the International Association of Geomagnetism and Aeronomy - Special sessions of auroral processes

    Science.gov (United States)

    Russell, C. T.

    1978-01-01

    Methods of timing magnetic substorms, the rapid fluctuations of aurorae, electromagnetic and electrostatic instabilities observed on the field lines of aurorae, the auroral microstructure, and the relationship of currents, electric field and particle precipitation to auroral form are discussed. Attention is given to such topics as D-perturbations as an indicator of substorm onset, the role of the magnetotail in substorms, spectral information derived from imaging data on aurorae, terrestrial kilometric radiation, and the importance of the mirror force in self-consistent models of particle fluxes, currents and potentials on auroral field lines.

  10. 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.

  11. A Proposal to Initiate Regional Studies of Ionospheric Irregularities in the African Region

    Science.gov (United States)

    2012-03-01

    Sandro M. Radicella Abdus Salam International Centre for Theoretical Physics Aeronomy and Radiopropagation Laboratory Strada Costiera, 11 Trieste...Physics Aeronomy and Radiopropagatio Laboratory Strada Costiera, 11 Trieste, Italy 34014 8. PERFORMING ORGANIZATION REPORT NUMBER N/A...at different longitudes (Gentile, et al., 2006). ICTP and Boston College (BC) through respectively the Aeronomy and Radiopropagation Laboratory (ARPL

  12. Seasonal Variation of the Quasi 5 Day Planetary Wave: Causes and Consequences for Polar Mesospheric Cloud Variability in 2007

    Science.gov (United States)

    2010-01-01

    oscillations. [5] The NASA Aeronomy of Ice in the Mesosphere (AIM) satellite is dedicated to the study of PMCs. AIM was launched into a sun synchronous orbit at...cloud imaging and particle size experiment on the Aeronomy of Ice in the Mesosphere mission: Instrument concept, design, calibration, and on‐orbit...A.W.Merkel, S.M. Bailey, J. M. Russell III, C. E. Randall, C. Jeppesen, and M. Callan (2009), The cloud imaging and particle size experiment on the Aeronomy of

  13. High-Altitude Data Assimilation System Experiments for the Northern Summer Mesosphere Season of 2007

    Science.gov (United States)

    2009-01-01

    variations in PMC frequency measured from the aeronomy of ice in the mesosphere (AIM) satellite. Synoptic maps of these diagnostic saturation ratios...compare well with seasonal variations in PM Cfrequency measured from the aeronomy of ice in themesosphere (AIM )satellite. Synoptic maps of these...data, such as provided by the aeronomy of ice in the mesosphere (AIM) satellite (Russell et al., 2008), are particularly valuable, either for direct

  14. Report on the HAARP 2008 Winter Campaign Focusing on Artificial Ionospheric Irregularities

    Science.gov (United States)

    2008-07-31

    Aeronomy (IUGG). DAYS BV SOLAKflOUJMV.’.\\.r. PVAi m IT :g <•> ;•; ;• » .••: .*• >• •• • J^ • *— V*V...Table Al. Definitive Kp, Ap, and Cp indices from the Association of Geomagnetism and Aeronomy International Service of Geomagnetic Indices...Ionospheric Monitoring System NRL Naval Research Laboratory NWRA NorthWest Research Associates ONR Office of Naval Research PARS Polar Aeronomy

  15. Tidally Induced Variations of PMC Altitudes and Ice Water Content Using a Data Assimilation System

    Science.gov (United States)

    2010-04-01

    SOFIE) and the Cloud Imaging and Particle Size (CIPS) instrument on the NASA 78 Aeronomy of Ice in the Mesosphere (AIM) satellite [Russell et al...Randall, C. Jeppesen and M. Callan, The cloud imaging and particle size experiment on 691 the aeronomy of ice in the mesosphere mission : Cloud...morphology for the northern 2007 692 season (2009), J. Atm. Sol.-Terr. Phys., 71, 356-364. 693 Russell, J.M. III et al., The Aeronomy of Ice in the

  16. HAARP 2011 Summer Student Research Campaign

    Science.gov (United States)

    2012-10-16

    lasting ten days to two weeks. The goal of this program, called the Polar Aeronomy and Radio Science (PARS) Summer School, was to acquaint university...Alaska, Fairbanks to conduct a comprehensive summer learning activity aimed at Graduate level students. Until 2008, this Polar Aeronomy and Radio...Research Associates ONR Office of Naval Research OPL Out-shifted Plasma Line PARS Polar Aeronomy and Radio Science PCA Polar Cap Absorption PDI

  17. On the Origin of Mid-Latitude Mesospheric Clouds: The July 2009 Cloud Outbreak

    Science.gov (United States)

    2011-09-01

    advanced micro- physical models. With the recent launch of the Aeronomy of Ice in the Mesosphere (AIM) satellite in 2007, an unprecedentedly detailed...Russell III, J.M., et al., 2009. Aeronomy of ice in the mesosphere (AIM): overview and early science results. J. Atmos. Sol. Terr. Phys. 71 (3–4), 289

  18. Assimilative Modeling of Observed Postmidnight Equatorial Plasma Depletions in June 2008 (Postprint)

    Science.gov (United States)

    2011-09-22

    of Geomagnetism and Aeronomy Working Group V‐MOD, 2010]. The global model of the PBMOD does not calculate self‐consistent fields of plasma...2006GL026161. International Association of Geomagnetism and Aeronomy Working Group V‐MOD (2010), International Geomagnetic Reference Field: The eleventh

  19. Solar Wind Driven Autoregression Model for Ionospheric Short Term Forecast (SWIF)

    Science.gov (United States)

    2008-06-01

    International Symposium on Equatorial Aeronomy (ISEA), 19-23 May 2008, Crete, Greece 6. “From DIAS to EURIPOS: the European Research Network of...International Symposium on Equatorial Aeronomy (ISEA), 19-23 May 2008, Crete, Greece EOARD Contract FA8655-07-M-4008, Final Report, June 2008

  20. Multiscale, Intermittent, Turbulent Fluctuations in Space Plasmas and Their Influence on the Interscale Behavior of the Space Environment

    Science.gov (United States)

    2012-06-26

    Belgium Institute of Spatial Aeronomy and Center of Excellence in Solar-Terrestrial Physics, 2010. Invited Lectures: 1. Invited Lecturer, (ROMA...NM 87545, USA 4Belgian Institute for Space Aeronomy , 1180 Brussels, Belgium 5Institute for Space Sciences, 077125 Bucharest, Romania 6Plasma and

  1. Operationally Responsive Spacelift: Supporting a Seven-Day Launch Schedule

    Science.gov (United States)

    2013-06-01

    Force Space Command AIM Aeronomy of Ice in the Mesosphere BMC Basic Mission Capable BOA Broad Ocean Area C&L Capabilities and Limitations CMR...The most recent Pegasus launch out of Vandenberg AFB was in April 2007. The Pegasus XL Rocket successfully delivered the 200kg Aeronomy of Ice in the

  2. The Community-based Whole Magnetosphere Model

    Science.gov (United States)

    2011-11-15

    Tribulations and Exultations in Coupling Models of the Magnetosphere with Ionosphere-Thermosphere Models, Plane- tary Aeronomy ISSI Meeting, Bern...Exultations in Coupling Models of the Magnetosphere CWMM-19 Ridley CWMM Final Report with Ionosphere-Thermosphere Models, Plane- tary Aeronomy ISSI

  3. Ionospheric Response to Solar Flares Using an Improved Version of SAMI2

    Science.gov (United States)

    2008-03-01

    Praxis Publishing, Ltd. Banks, P. M., and G. Kockarts (1973), Aeronomy , Academic Press, Inc. Chamberlin, P. C. (2005), Flare irradiance spectral...for climate change research, aeronomy , and space system engineering, Advances in Space Research, 34, 1736. Tsurutani, B. T., et al. (2005), The

  4. Spatial Heterodyne Imager for Mesospheric Radicals on STPSat-1

    Science.gov (United States)

    2010-10-22

    by many other sat- ellite experiments such as MLS, OSIRIS, or the suite of instruments on the NASA Aeronomy of Ice in the Meso- sphere (AIM... Aeronomy of Ice in the Mesosphere (AIM) mission: Overview and early science results, J. Atmos. Sol. Terr. Phys., 71, 289–299. Sander, S. P., et al

  5. Tidally Induced Variations of Polar Mesospheric Cloud Altitudes and Ice Water Content using a Data Assimilation System

    Science.gov (United States)

    2010-01-01

    instrument on the NASA Aeronomy of Ice in the Mesosphere (AIM) satellite [Russell et al., 2009; Hervig et al., 2009a] as well as the Student Nitric Oxide...Russell III, C. E. Randall, C. Jeppesen, and M. Callan (2009), The cloud imaging and particle size experiment on the aeronomy of ice in the mesosphere...mission: Cloud morphology for the northern 2007 season, J. Atmos. Sol.‐Terr. Phys., 71, 356–364. Russell, J. M., III, et al. (2009), The Aeronomy of

  6. 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...

  7. Evaluation of candidate geomagnetic field models for IGRF-12

    DEFF Research Database (Denmark)

    Thébault, Erwan; Finlay, Chris; Alken, Patrick

    2015-01-01

    Background: The 12th revision of the International Geomagnetic Reference Field (IGRF) was issued in December 2014 by the International Association of Geomagnetism and Aeronomy (IAGA) Division V Working Group V-MOD (http://www.ngdc.noaa.gov/IAGA/vmod/igrf.html). This revision comprises new spheric...

  8. 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.

  9. 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...

  10. Dissociative recombination of atmospheric ions : towards unravelling the physics behind airglows

    NARCIS (Netherlands)

    Petrignani, Annemieke

    2005-01-01

    This thesis presents experimental data on the dissociative recombination reaction between electrons and the molecular ions, oxygen, nitric oxide, and nitric-oxide-dimers, as well as a computational study of the reaction. The presented research is performed in the context of aeronomy. The products of

  11. 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.

  12. Absolute Positioning Using The Earth’s Magnetic Anomaly Field

    Science.gov (United States)

    2016-09-15

    Aeronomy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 RTP Reduction to the Pole ...35 ESDI Equivalent Source Dipole Inversion . . . . . . . . . . . . . . . . . . . . . . . . . . 38 NAMAD North American Magnetic Anomaly...of 1500 nano-Teslas. This indicates that navigation near the Earth’s poles may potentially be difficult [5]. Magnetospheric Effects on the Magnetic

  13. International Symposium on Molecular Spectroscopy (46th) Held in Columbus, Ohio on 17-21 June 1991,

    Science.gov (United States)

    1991-07-01

    Departmento de Estructura Atomico-Nolecular y Espectroscopie, Universidad Coaplutense de Madrid, 28040 Madrid, Spain. MF8. TORSIONAL SPECTRA OF CH3CH3 AND... Estructura de la Materia, Consejo Superior de Investigaciones Cientificas, 28006 Madrid, Spain; J. B. BURKHOLDER, C J. HOWARD, Aeronomy Laboratory...INFRARED SPECTRUM OF ACETE ............................ 15 min.(4:42) Y. G. SNEYERS, M. L. SENENT, Instituto do Estructura do la Materia, Consejo

  14. International Geomagnetic Reference Field—the eighth generation

    Science.gov (United States)

    Mandea, Mioara; Macmillan, Susan

    2000-12-01

    The eighth generation of the International Geomagnetic Reference Field (IGRF) was adopted in 1999 by the International Association of Geomagnetism and Aeronomy (IAGA) Division V, Working Group 8. This differs from the previous generation by the addition of the IGRF 2000 which comprises a main-field model for the epoch 2000.0 and a predictive secular-variation model for 2000.0-2005.0. This paper lists the IGRF coefficients and includes contour maps computed using IGRF 2000.

  15. [Forms of histograms constructed from measurements of alpha-decay of 228Ra in Lindau (Germany) and neutron fluxes in Moscow change synchronously according to the local time].

    Science.gov (United States)

    Zenchenko, K I; Zenchenko, T A; Kuzhevskiĭ, B M; Vilken, B; Axford, Y; Shnol', S E

    2001-01-01

    In joint experiments performed at Max Plank Institute of Aeronomy (Germany) and the Institute of Theoretical and Experimental Biophysics in Pushchino, the main manifestations of the phenomenon of macroscopic fluctuations were confirmed. An increased probability of the similarity in synchronous histograms in independent measurements performed by two installations in one laboratory and in two laboratories separated by a distance of 2000 km was shown. In the latter case, the similarity of histograms is most probable at the same local time.

  16. AE8/AP8 Implementations in AE9/AP9, IRBEM, and SPENVIS

    Science.gov (United States)

    2014-02-18

    period applies to orbit generation only; AE8/AP8 utilizes geomagnetic field models from other epochs as specified in the table below.) SHIELDOSE2 model...Cain, J. C., S. J. Hendricks, R. A. Langel, and W. V. Hudson (1967), A proposed model for the international geomagnetic reference field, 1965, J...trapped particle fluxes with the NASA models AP-8 and AE-8, Radiat. Meas., 26, pp. 947-952. International Association of Geomagnetism and Aeronomy

  17. 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

  18. PICASSO VISION instrument design, engineering model test results, and flight model development status

    Science.gov (United States)

    Näsilä, Antti; Holmlund, Christer; Mannila, Rami; Näkki, Ismo; Ojanen, Harri J.; Akujärvi, Altti; Saari, Heikki; Fussen, Didier; Pieroux, Didier; Demoulin, Philippe

    2016-10-01

    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 Technical Research Centre of Finland Ltd, Clyde Space Ltd. (UK) and Centre Spatial de Liège (BE). The test campaign for the engineering model of the PICASSO VISION instrument, a miniaturized nanosatellite spectral imager, has been successfully completed. The test results look very promising. The proto-flight model of VISION has also been successfully integrated and it is waiting for the final integration to the satellite platform.

  19. 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.

  20. 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 ...... for epoch 2015.0 and their predicted rates of change for 2015.0-2020.0. We also update the magnetic pole positions and discuss briefly the latest changes and possible future trends of the Earth’s magnetic field....

  1. 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

  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. International Geomagnetic Reference Field: the 12th generation

    OpenAIRE

    2015-01-01

    International audience; 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 2010.0, a main field model for epoch 2015.0, and a linear annual predictive secular variation model for 2015.0-2020.0. Here, we present the equations defining the IGRF model, p...

  4. Next Generation Transport Phenomenology Model

    Science.gov (United States)

    Strickland, Douglas J.; Knight, Harold; Evans, J. Scott

    2004-01-01

    This report describes the progress made in Quarter 3 of Contract Year 3 on the development of Aeronomy Phenomenology Modeling Tool (APMT), an open-source, component-based, client-server architecture for distributed modeling, analysis, and simulation activities focused on electron and photon transport for general atmospheres. In the past quarter, column emission rate computations were implemented in Java, preexisting Fortran programs for computing synthetic spectra were embedded into APMT through Java wrappers, and work began on a web-based user interface for setting input parameters and running the photoelectron and auroral electron transport models.

  5. The Contribution of a Geophysical Data Service: The International Service of Geomagnetic Indices

    Directory of Open Access Journals (Sweden)

    M Menvielle

    2013-01-01

    Full Text Available Geomagnetic indices are basic data in Solar-Terrestrial physics and in operational Space Weather activities. The International Service of Geomagnetic Indices (ISGI is in charge of the derivation and dissemination of the geomagnetic indices that are acknowledged by the International Association of Geomagnetism and Aeronomy (IAGA, an IUGG association. Institutes that are not part of ISGI started early in the Internet age to circulate on-line preliminary values of geomagnetic indices. In the absence of quality stamping, this resulted in a very confusing situation. The ISGI label was found to be the simplest and the safest way to insure quality stamping of circulated geomagnetic indices.

  6. 第11届国际地磁学与高空物理学协会科学会议介绍%Introduction of the IAGA 11th Scientific Assembly

    Institute of Scientific and Technical Information of China (English)

    张素琴; 杨冬梅; 陈斌

    2009-01-01

    国际地磁学与高空物理学协会(International Association of Geomagnetism and Aeronomy, IAGA)第11届科学会议于2009年8月23日至30日在匈牙利的索普隆市举行, 来自52个国家的790多人参加了这次会议. 其中, 参加此次会议的中国代表共13人.

  7. The 9th-Generation International Geomagnetic Reference Field

    Science.gov (United States)

    Macmillan, S.; Maus, S.; Bondar, T.; Chambodut, A.; Golovkov, V.; Holme, R.; Langlais, B.; Lesur, V.; Lowes, F.; Lühr, H.; Mai, W.; Mandea, M.; Olsen, N.; Rother, M.; Sabaka, T.; Thomson, A.; Wardinski, I.

    2003-12-01

    The International Association of Geomagnetism and Aeronomy has recently released the 9th-Generation International Geomagnetic Reference Field-the latest version of a standard mathematical description of the Earth's main magnetic field used widely in studies of the Earth's deep interior, its crust and its ionosphere and magnetosphere. The coefficients were recently finalized at the XXIII General Assembly of the International Union of Geophysics and Geodesy, held at Sapporo in Japan in 2003 July. The IGRF is the product of a huge collaborative effort between magnetic field modellers and the institutes involved in collecting and disseminating magnetic field data from satellites and from observatories and surveys around the world.

  8. The 10th generation international geomagnetic reference field

    Science.gov (United States)

    Maus, S.; Macmillan, S.; Chernova, T.; Choi, S.; Dater, D.; Golovkov, V.; Lesur, V.; Lowes, F.; Lühr, H.; Mai, W.; McLean, S.; Olsen, N.; Rother, M.; Sabaka, T.; Thomson, A.; Zvereva, T.; International Association of Geomagnetism, Aeronomy (IAGA), Division V, Working Group VMOD

    The International Association of Geomagnetism and Aeronomy (IAGA) on 12 December 2004 released the 10th generation International Geomagnetic Reference Field (IGRF)—the latest version of a standard mathematical description of the Earth's main magnetic field and used widely in studies of the Earth's deep interior, its crust, ionosphere and magnetosphere. The coefficients were finalised by a task force of IAGA. The IGRF is the product of a large collaborative effort between magnetic field modellers and the institutes involved in collecting and disseminating magnetic field data from satellites and observatories around the world.

  9. The 10th-Generation International Geomagnetic Reference Field

    Science.gov (United States)

    2005-06-01

    The International Association of Geomagnetism and Aeronomy (IAGA) on 2004 December 12 has released the 10th-Generation International Geomagnetic Reference Field-the latest version of a standard mathematical description of the Earth's main magnetic field used widely in studies of the Earth's deep interior, its crust, ionosphere and magnetosphere. The coefficients were finalized by a task force of IAGA. The IGRF is the product of a large collaborative effort between magnetic field modellers and the institutes involved in collecting and disseminating magnetic field data from satellites and observatories around the world.

  10. 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.

  11. 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.

  12. 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.

  13. CEDAR 88

    Science.gov (United States)

    Meriwether, John W., Jr.; Killeen, Timothy

    The third workshop session of the National Science Foundation's Coupling Energetics, and Dynamics of Atmospheric Regions (CEDAR) initiative took place at the National Bureau of Standards and National Center for Atmospheric Research institutions in Boulder, Colo., June 6-10, and was attended by 155 participants, including about 40 graduate students.The CEDAR initiative represents the fruit of many years of efforts by the aeronomy community and NSF to modernize the techniques used to understand the many processes of the upper atmosphere both theoretically and experimentally. Since the beginning of this initiative (under the old name of Ground-Based Optical Aeronomy) with a summer meeting in Logan, Utah, in 1983, there has been a workshop meeting every summer. The 1988 CEDAR meeting, in particular, reflected the growing maturity of the CEDAR initiative. The meeting was well attended, and, in general, we found fewer participants drawn to the meeting just by curiosity and more who came because they expected the workshop activities would be time well spent.

  14. Heliophysics: Active Stars, their Astrospheres, and Impacts on Planetary Environments

    Science.gov (United States)

    Schrijver, C. J.; Bagenal, F.; Sojka, J. J.

    2016-04-01

    Preface; 1. Introduction Carolus J. Schrijver, Frances Bagenal and Jan J. Sojka; 2. Solar explosive activity throughout the evolution of the Solar System Rachel Osten; 3. Astrospheres, stellar winds, and the interstellar medium Brian Wood and Jeffrey L. Linsky; 4. Effects of stellar eruptions throughout astrospheres Ofer Cohen; 5. Characteristics of planetary systems Debra Fischer and Ji Wang; 6. Planetary dynamos: updates and new frontiers Sabine Stanley; 7. Climates of terrestrial planets David Brain; 8. Upper atmospheres of the giant planets Luke Moore, Tom Stallard and Marina Garland; 9. Aeronomy of terrestrial upper atmospheres David E. Siskind and Stephen W. Bougher; 10. Moons, asteroids, and comets interacting with their surroundings Margaret G. Kivelson; 11. Dusty plasmas Mihály Horányi; 12. Energetic-particle environments in the Solar System Norbert Krupp; 13. Heliophysics with radio scintillation and occultation Mario M. Bisi; Appendix 1. Authors and editors; List of illustrations; List of tables; References; Index.

  15. 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.

  16. Billy M. McCormac (1920-1999)

    Science.gov (United States)

    Walt, Martin

    Billy M. McCormac died on September 13, 1999, at age 79. His many friends and colleagues will remember him for the legendary International Institutes on Space Science and Aeronomy, which he organized between 1965 and 1975.Billy was born and raised in Zanesville, Ohio, and graduated from Ohio State University in 1943 in the midst of World War II. He joined the Army as a 2nd Lieutenant and served in Europe and Korea. As a career officer he was sent to graduate school at the University of Virginia, where he received his Ph.D. in nuclear physics in 1957. He held various scientific positions in the Army until his retirement as a Lieutenant Colonel in 1963. His last military position was Chief of Electromagnetics at the Defense Atomic Support Agency, where he was responsible for experiments measuring the effects of the high-altitude nuclear weapon explosions in the Pacific.

  17. Comparison of transport equations based on Maxwellian and bi-Maxwellian distributions for anisotropic plasmas

    Science.gov (United States)

    Barakat, A. R.; Schunk, R. W.

    1982-01-01

    A wide variety of plasma flow conditions is found in aeronomy and space plasma physics. Transport equations based on an isotropic Maxwellian vilecity distribution function can be used to describe plasma flows which contain 'small' temperature anisotropies. However, for plasma flows characterized by large temperature anisotropies, transport equations based on an anisotropic bi-Maxwellian (or two-temperature) velocity distribution function are expected to provide a much better description of the plasma transport properties. The present investigation is concerned with the extent to which transport equations based on both Maxwellian and bi-Maxwellian series expansions can describe plasma flows characterized by non-Maxwellian velocity distributions, giving particular attention to a modelling of the anisotropic character of the distribution function. The obtained results should provide clues as to the extent to which a given series expansion can account for the anisotropic character of a plasma.

  18. 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.

  19. International Geomagnetic Reference Field: the 12th generation

    Science.gov (United States)

    Thébault, Erwan; Finlay, Christopher C.; Beggan, Ciarán D.; Alken, Patrick; Aubert, Julien; Barrois, Olivier; Bertrand, Francois; Bondar, Tatiana; Boness, Axel; Brocco, Laura; Canet, Elisabeth; Chambodut, Aude; Chulliat, Arnaud; Coïsson, Pierdavide; Civet, François; Du, Aimin; Fournier, Alexandre; Fratter, Isabelle; Gillet, Nicolas; Hamilton, Brian; Hamoudi, Mohamed; Hulot, Gauthier; Jager, Thomas; Korte, Monika; Kuang, Weijia; Lalanne, Xavier; Langlais, Benoit; Léger, Jean-Michel; Lesur, Vincent; Lowes, Frank J.; Macmillan, Susan; Mandea, Mioara; Manoj, Chandrasekharan; Maus, Stefan; Olsen, Nils; Petrov, Valeriy; Ridley, Victoria; Rother, Martin; Sabaka, Terence J.; Saturnino, Diana; Schachtschneider, Reyko; Sirol, Olivier; Tangborn, Andrew; Thomson, Alan; Tøffner-Clausen, Lars; Vigneron, Pierre; Wardinski, Ingo; Zvereva, Tatiana

    2015-05-01

    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 2010.0, a main field model for epoch 2015.0, and a linear annual predictive secular variation model for 2015.0-2020.0. Here, we present the equations defining the IGRF model, provide the spherical harmonic coefficients, and provide maps of the magnetic declination, inclination, and total intensity for epoch 2015.0 and their predicted rates of change for 2015.0-2020.0. We also update the magnetic pole positions and discuss briefly the latest changes and possible future trends of the Earth's magnetic field.

  20. Rate constant for the reaction of atomic oxygen with phosphine at 298 K

    Science.gov (United States)

    Stief, L. J.; Payne, W. A.; Nava, D. F.

    1987-01-01

    The rate constant for the reaction of atomic oxygen with phosphine has been measured at 298 K using flash photolysis combined with time-resolved detection of O(3P) via resonance fluorescence. Atomic oxygen was produced by flash photolysis of N2O or NO highly diluted in argon. The results were shown to be independent of (PH3), (O), total pressure and the source of O(3P). The mean value of all the experiments is k1 = (3.6 + or -0.8) x 10 to the -11th cu cm/s (1 sigma). Two previous measurements of k1 differed by more than an order of magnitude, and the results support the higher value obtained in a discharge flow-mass spectrometry study. A comparison with rate data for other atomic and free radical reactions with phosphine is presented, and the role of these reactions in the aeronomy or photochemistry of Jupiter and Saturn is briefly considered.

  1. International Geomagnetic Reference Field: the seventh generation.

    Science.gov (United States)

    Barton, C. E.

    A seventh-generation revision of the International Geomagnetic Reference Field (IGRF) was adopted by the International Association of Geomagnetism and Aeronomy (IAGA) at the XXI General Assembly of the International Union of Geodesy and Geophysics in July 1995. The new spherical harmonic models adopted are based on weighted averages of candidate models submitted by NASA's Goddard Space Flight Center, the Russian Institute of Terrestrial Magnetism, Ionospheric, and Radio Wave Propagation - IZMIRAN, and jointly by the US Naval Oceanographic Office and the British Geological Survey. The revised IGRF specifies the Earth's main field from 1900 to 2000 and is declared to be definitive from 1945 to 1990. This paper lists the IGRF coefficients, describes the derivation of the new IGRF models, and examines aspects of the IGRF's accuracy, continuity, and behaviour during the 20th century.

  2. International Geomagnetic Reference Field—the tenth generation

    Science.gov (United States)

    Macmillan, Susan; Maus, Stefan

    2005-12-01

    The International Geomagnetic Reference Field (IGRF) 10th Generation was adopted in 2004 by the International Association of Geomagnetism and Aeronomy (IAGA) Working Group V-MOD. It is the latest version of a standard mathematical description of the Earth's main magnetic field and is used widely in studies of the Earth's deep interior, its crust and its ionosphere and magnetosphere. This generation differs from the previous generation with the replacement of the secular-variation model for 2000.0-2005.0 with a main-field model at 2005.0 and a secular-variation model for 2005.0-2010.0. The IGRF is the product of a huge collaborative effort between magnetic field modellers and the institutes involved in collecting and disseminating magnetic field data from satellites and from observatories and surveys around the world. This paper lists the new coefficients and includes contour maps and pole positions.

  3. 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.

  4. 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).

  5. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Poppe, Andrew, E-mail: poppe@lasp.colorado.ed [Laboratory for Atmospheric and Space Physics, 1234 Innovation Drive, Boulder, CO 80303 (United States); Department of Physics, University of Colorado, 2000 Colorado Ave, Boulder, CO 80309 (United States); Colorado Center for Lunar Dust and Atmospheric Studies, University of Colorado at Boulder, Boulder, CO 80303 (United States); Jacobsmeyer, Brian [Laboratory for Atmospheric and Space Physics, 1234 Innovation Drive, Boulder, CO 80303 (United States); Department of Physics, University of Colorado, 2000 Colorado Ave, Boulder, CO 80309 (United States); James, David [Laboratory for Atmospheric and Space Physics, 1234 Innovation Drive, Boulder, CO 80303 (United States); Horanyi, Mihaly [Laboratory for Atmospheric and Space Physics, 1234 Innovation Drive, Boulder, CO 80303 (United States); Department of Physics, University of Colorado, 2000 Colorado Ave, Boulder, CO 80309 (United States); Colorado Center for Lunar Dust and Atmospheric Studies, University of Colorado at Boulder, Boulder, CO 80303 (United States)

    2010-10-21

    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.

  7. Periodicities in Solar Coronal Mass Ejections

    CERN Document Server

    Lou, Y Q; Fan, Z; Wang, S; Wang, J

    2003-01-01

    Mid-term quasi-periodicities in solar coronal mass ejections (CMEs) during the most recent solar maximum cycle 23 are reported here for the first time using the four-year data (February 5, 1999 to February 10, 2003) of the Large Angle Spectrometric Coronagraph (LASCO) onboard the Solar and Heliospheric Observatory (SOHO). In parallel, mid-term quasi-periodicities in solar X-ray flares (class >M5.0) from the Geosynchronous Operational Environment Satellites (GOES) and in daily averages of Ap index for geomagnetic disturbances from the World Data Center (WDC) at the International Association for Geomagnetism and Aeronomy (IAGA) are also examined for the same four-year time span. Several conceptual aspects of possible equatorially trapped Rossby-type waves at and beneath the solar photosphere are discussed.

  8. The LYRA Instrument Onboard PROBA2: Description and In-Flight Performance

    CERN Document Server

    Dominique, M; Schmutz, W; Dammasch, I E; Shapiro, A I; Kretzschmar, M; Zhukov, A N; Gillotay, D; Stockman, Y; BenMoussa, A; 10.1007/s11207-013-0252-5

    2013-01-01

    The Large Yield Radiometer (LYRA) is an XUV-EUV-MUV (soft X-ray to mid-ultraviolet) solar radiometer onboard the European Space Agency PROBA2 mission that was launched in November 2009. LYRA acquires solar irradiance measurements at a high cadence (nominally 20 Hz) in four broad spectral channels, from soft X-ray to MUV, that have been chosen for their relevance to solar physics, space weather and aeronomy. In this article, we briefly review the design of the instrument, give an overview of the data products distributed through the instrument website, and describe the way that data are calibrated. We also briefly present a summary of the main fields of research currently under investigation by the LYRA consortium.

  9. 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...

  10. 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

  11. 10th Generation International Geomagnetic Reference Field

    Science.gov (United States)

    Maus, Stefan; Macmillan, Susan

    2005-04-01

    The International Association of Geomagnetism and Aeronomy (IAGA) released the 10th Generation International Geomagnetic Reference Field (IGRF) on 12 December 2004. This is the latest version of a standard mathematical description of the Earth's main magnetic field, and is used widely in studies of the Earth's deep interior, crust, ionosphere, and magnetosphere. The coefficients were finalized by a task force of IAGA, Division V, Working Group V-MOD: Geomagnetic Field Modeling. The IGRF is the product of a large collaborative effort between magnetic field modelers and the institutes around the world involved in collecting and disseminating magnetic field data from satellites and observatories. The IGRF is a series of mathematical models of the Earth's main field and its annual rate of change (secular variation). The sources of the main magnetic field are electric currents in the Earth and the magnetization of crustal rocks.

  12. 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...

  13. 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.

  14. 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.

  15. 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.

  16. Candidates for office 2004-2006

    Science.gov (United States)

    Timothy L. Killeen. AGU member since 1981. Director of the National Center for Atmospheric Research (NCAR); Senior Scientist, High Altitude Observatory; Adjunct Professor, University of Michigan. Major areas of interest include space physics and aeronomy remote sensing, and interdisciplinary science education. B.S., Physics and Astronomy (first class honors), 1972, University College London; Ph.D., Atomic and Molecular Physics, 1975, University College London. University of Michigan: Researcher and Professor of Atmospheric, Oceanic, and Space Sciences, 1978-2000 Director of the Space Physics Research Laboratory 1993-1998 Associate Vice-President for Research, 1997-2000. Visiting senior scientist at NASA Goddard Space Flight Center, 1992. Program Committee, American Association for the Advancement of Science; Council Member, American Meteorological Society; Editor-in-Chief, Journal of Atmospheric and Solar-Terrestrial Physics; Chair, Jerome K.Weisner National Policy Symposium on the Integration of Research and Education, 1999. Authored over 140 publications, 57 in AGU journals. Significant publications include: Interaction of low energy positrons with gaseous atoms and molecules, Atomic Physics, 4, 1975; Energetics and dynamics of the thermosphere, Reviews of Geophysics, 1987; The upper mesosphere and lower thermosphere, AGU Geophysical Monograph, 1995, Excellence in Teaching and Research awards, College of Engineering, University of Michigan; recipient of two NASA Achievement Awards; former chair, NASA Space Physics Subcommittee; former chair, National Science Foundation (NSF) Coupling, Energetics and Dynamics of Atmospheric Regions (CEDAR) program; former member, NSF Advisory Committee for Geosciences, and chair of NSF's Atmospheric Sciences Subcommittee, 1999-2002 member, NASA Earth Science Enterprise Advisory Committee; member of various National Academy of Science/National Research Council Committees; cochair, American Association for the Advancement of Science

  17. 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.

  18. Laser Measurements of the H Atom + Ozone Rate Constant at Atmospheric Temperatures

    Science.gov (United States)

    Liu, Y.; Smith, G. P.; Peng, J.; Reppert, K. J.; Callahan, S. L.

    2015-12-01

    The exothermic H + O3 reaction produces OH(v) Meinel band emissions, used to derive mesospheric H concentrations and chemical heating rates. We have remeasured its rate constant to reduce resulting uncertainties and the measurement extend to lower mesospheric temperatures using modern laser techniques. H atoms are produced by pulsed ultraviolet laser trace photolysis of O3, followed by reaction of O(D) with added H2. A second, delayed, frequency-mixed dye laser measures the reaction decay rate with the remaining ozone by laser induced fluorescence. We monitor either the H atom decay by 2 photon excitation at 205 nm and detection of red fluorescence, or the OH(v=9) product time evolution with excitation of the B-X (0,9) band at 237 nm and emission in blue B-A bands. By cooling the enclosed low pressure flow cell we obtained measurements from 146-305 K. Small kinetic modeling corrections are made for secondary regeneration of H atoms. The results fully confirm the current NASA JPL recommendation for this rate constant, and establish its extrapolation down to the lower temperatures of the mesosphere. This work was supported by the NSF Aeronomy Program and an NSF Physics summer REU student grant.

  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. 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...

  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. 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.

  4. Sun-earth connection education through modern views of ancient

    Science.gov (United States)

    Thieman, J. R.

    The NASA Sun-Earth Connection Education Forum (SECEF) has the responsibility of using the latest science results from the study of solar physics, space physics, and aeronomy to inspire students in the classroom and to inform the public in general. SECEF works with NASA's Sun-Earth Connection spaceflight missions to accomplish this goal. Each year the missions and SECEF combine to promote their science through a major event designed to attract the attention of all. In late 2004 and 2005 the event will be the study of solar observatories created by ancient peoples and a comparison of their knowledge and culture to present understanding. Two solar observatory sites will be featured, Chaco Canyon in the U.S. and Chichen Itza in Mexico. There are many other places throughout the world that could also be featured as solar observatories and some of these may be described on the SECEF web site or used in future occurrences. Special emphasis is placed on events associated with the solstice and equinox dates. It is hoped that there will be happenings around the world on these days and SECEF will work with many museums, science centers, and other groups to help make this happen. Plans for the 2005 Ancient Observatories event and possible future events on the same subject will be described.

  5. 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.

  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. 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).

  9. Barreira do Inferno: Five years of ozone research

    Science.gov (United States)

    Kirchhoff, V. W. J. H.; Motta, A. G.; Azambuja, S. O.

    1983-12-01

    A five-year tropospheric ozone research project carried out from 1978 to 1983 under the aegis of the Institute of Space Research and the Launching Center at Barreira do Inferno is described. The principal means of obtaining data was by sondes launched twice a month from November 1978 until mid-1981. Measurements were made by ECC sondes and by Loki, Super-Loki, and Super-Arcas rockets equipped with optical and fluorescent sounding devices. The interest in ozone research is based on the ability of ozone to absorb ultraviolet radiation and thereby affect stratospheric temperature. Results revealed that average ozone concentration over the Brazilian state of Natal was 0.025 ppm (parts per million) with the maximum concentration occurring at 28 km altitude. It was also found that there was 30 percent higher ozone density over Natal than over regions of lower latitudes. In addition, 15 percent more ozone layer density was measured over Natal than over equatorial areas as determined by satellites. Total ozone measured by ECC sondes and by two Dobson spectrophotometers differed only by 4 percent. Higher concentrations of ozone are attributed to nitrogen concentrations, in contradiction with prevailing views. It is concluded that continued monitoring of ozone density is important for further theoretical investigation of the aeronomy of ozone.

  10. 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!

  11. Allan V. Cox: AGU President 1978”1980

    Science.gov (United States)

    Richman, Barbara T.

    When Allan V. Cox was presented AGU's John Adam Fleming Medal in 1969, John Verhoogen described Cox's work as “characterized by painstaking care, proper attention to and use of statistics, and great insight.” Those same thoughts were echoed on February 3, 1987, during the memorial service for Cox, who died in a bicycling accident on January 27. The Stanford Memorial Church was crowded with colleagues, students, and friends.The Fleming Medal was presented to Cox in recognition of his studies on the fluctuation of the geomagnetic field. These studies helped to confirm theories of continental drift and seafloor spreading. The medal is awarded annually by AGU for original research and technical leadership in geomagnetism, atmospheric electricity, aeronomy, and related sciences. In addition to the Fleming Medal, Cox received the Antarctic Service Medal in 1970, the Vetlesen Prize in 1971, and the Arthur L. Day Prize of the National Academy of Sciences in 1984. He was a Fellow of AGU and a member of the National Academy of Sciences.

  12. Simultaneous PMC and PMSE observations with a ground-based lidar and SuperDARN HF radar at Syowa Station, Antarctica

    Directory of Open Access Journals (Sweden)

    H. Suzuki

    2013-10-01

    Full Text Available A Rayleigh–Raman lidar system was installed in January 2011 at Syowa Station, Antarctica (69.0° S, 39.6° E. Polar mesospheric clouds (PMCs were detected by lidar at around 22:30 UTC (LT −3 h on 4 February 2011, which was the first day of observation. This was the first detection of PMCs over Syowa Station by lidar. On the same day, a Super Dual Auroral Radar Network (SuperDARN HF radar with oblique-incidence beams detected polar mesospheric summer echoes (PMSE between 21:30 and 23:00 UTC. This event is regarded as the last PMC activity around Syowa Station during the austral summer season (2010–2011, since no other PMC signals were detected by lidar in February 2011. This is consistent with results of PMC and mesopause temperature observations by satellite-born instruments of AIM (Aeronomy of Ice in the Mesosphere/CIPS (Cloud Imaging and Particle Size and AURA/MLS (Microwave Limb Sounder and horizontal wind measurements taken by a separate MF radar. Doppler velocity of PMSE observed by the HF radar showed motion toward Syowa Station (westward. This westward motion is consistent with the wind velocities obtained by the MF radar. However, the PMSE region showed horizontal motion from a north-to-south direction during the PMC event. This event indicates that the apparent horizontal motion of the PMSE region can deviate from neutral wind directions and observed Doppler velocities.

  13. Mechanics of Turbulence of Multicomponent Gases

    Science.gov (United States)

    Marov, Mikhail Ya.; Kolesnichenko, Aleksander V.

    2002-02-01

    Turbulence in multicomponent reacting gas mixtures is an important mechanism underlying numerous natural phenomena closely related to the study of our space environment. This book develops a new mathematical approach for modelling multicomponent gas turbulence that adequately describes the combined processes of dynamics and heat and mass transfer when chemical kinetics and turbulent mixing are equally important. The developed models include the evolutionary transfer equations for the single-point second correlation moments of turbulent fluctuations of thermohydrodynamical parameters. The phenomenological approach to the closure problem in hydrodynamic equations of mean motion at the level of the first order moments is based on the thermodynamics of irreversible processes and enables defining relationships in a more general form as compared to those conventionally deduced using the mixing path concept. Based on the developed approach, turbulent exchange factors for a planetary upper atmosphere are evaluated, and a turbulent model of a protoplanetary accretion gas-dust disk involving heat and mass transfer and coagulation is also considered. As compared to previously published books on the problem of turbulence, this book deals, for the first time, with the complicated models of reacting gas mixtures. It is intended for graduate and postgraduate students in the fields of fluid gas dynamics, astrophysics, space physics, planetary sciences, and aeronomy, and especially for those dealing with computer modelling of the processes in such natural media. The book may also be of interest to specialists in the relevant fields of ecology, engineering, and material processing.

  14. 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.

  15. CN and NH2 atmospheres of Comet C/1999 J3 (Linear)

    Science.gov (United States)

    Korsun, P. P.; Jockers, K.

    2000-09-01

    Observations of Comet C/1999 J3 were made at the 2-m telescope of the Pik Terskol Observatory on September 19, 1999. Narrow-band CCD images of the CN, NH2, and dust atmospheres have been recorded using the two-channel focal reducer of the Max-Plank-Institute for Aeronomy. To fit distributions of the CN and NH2 molecules in the comet atmosphere Monte Carlo model was adopted. Model calculations were successful with photodissociation lifetimes equal to τCN=1.5×105s and τ{CNparent}=3.2×104s for CN and its parent, τ{NH2}=1.0×105s and τ{NH2parent}=5.0×103s for NH2 and its parent, respectively. These results are in agreement with HCN as the main source of the CN radicals and NH3 as the main source of the NH2 radicals in the atmosphere of Comet C/1999 J3 (Linear). The gas-production rates of CN, Q(CN)=3.8×1025 mol-1, and NH2, Q(NH2)=2.6×1025 mol-1, have been determined as well. These values are about 0.24% and 0.16%, respectively, of the water production rate.

  16. The dust tail of the distant comet C/1999 J2 (Skiff)

    Science.gov (United States)

    Korsun, P.; Jockers, K.; Chorny, G.

    CCD observations of comet C/1999 J2 (Skiff) were made at the Pik Terskol Observatory on September 15, 1999. The 2-m telescope equipped with the two- channel focal reducer of the Max-Plank-Institute for Aeronomy has been used to study the cometary environment. In spite of large heliocentric distance, 7.24 A.U., a straight narrow dust tail with fairly well defined boundaries was recorded. This provides a unique opportunity to study the peculiarity of dust, which is not driven by water vapour. To fit the dust tail a Monte Carlo model was developed. We trace the trajectories of about 107 sample grains to construct the detailed brightness distribution in the comet tail. The simulated isophote field and the observed one agree very well. In our model we also take into account the heliocentric dependence of the dust production rate and ejection velocity, and the dust ejection anisotropy. To transform the particle distribution to brightness in the modeled tail we calculate the scattering cross section of the individual particles using Mie theory. The age, the ejection velocity, the dust-loss distribution, and the size distribution of the dust particles have been derived from the model giving the best fit. The intensity map is in agreement with icy grains.

  17. 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.

  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. 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.

  20. 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...

  1. Mini MAX-DOAS Measurements of Air Pollutants over China

    Science.gov (United States)

    Staadt, Steffen; Hao, Nan; Trautmann, Thomas

    2016-08-01

    This study continues the work of Clémer et al., (2010) and is aimed to improve trace gas retrievals with mini MAX-DOAS measurements in Nanjing. Based on that work, aerosol extinction vertical profiles are retrieved using the bePRO inversion algorithm developed by the Royal Belgian Institute for Space Aeronomy (BIRA- IASB). Afterwards, the tropospheric trace gas vertical profiles and vertical column densities (VCDs) are retrieved by applying the optimal estimation method to the O4 MAX-DOAS measurements. The Profiles for N O2 , S O2 , glyoxal, formaldehyde and nitrous acid are obtained with different results and different settings for the DOAS measurement. The AODs show small positive correlation against the AERONET values. For NO2, the retrieval shows reasonable concentrations in winter as opposed to summer and has small positive correlations with GOME-2 data. The SO2 VCDs are not correlated with the GOME-2 data, due to high uncertainties from MAX-DOAS and satellite retrievals, while the vertical mixing ratios (VMR) show good agreement with in-situ data (SORPES) at Nanjing. Nitrous acid shows a maximum in winter and a minimum in summer, while glyoxal has its maximum in August and September.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. Applying Forecast Models from the Center for Integrated Space Weather Modeling

    Science.gov (United States)

    Gehmeyr, M.; Baker, D. N.; Millward, G.; Odstrcil, D.

    2007-12-01

    The Center for Integrated Space Weather Modeling (CISM) has developed three forecast models (FMs) for the Sun-Earth chain. They have been matured by various degrees toward the operational stage. The Sun-Earth FM suite comprises empirical and physical models: the Planetary Equivalent Amplitude (AP-FM), the Solar Wind (SW- FM), and the Geospace (GS-FM) models. We give a brief overview of these forecast models and touch briefly on the associated validation studies. We demonstrate the utility of the models: AP-FM supporting the operations of the AIM (Aeronomy of Ice in the Mesosphere) mission soon after launch; SW-FM providing assistance with the interpretation of the STEREO beacon data; and GS-FM combining model and observed data to characterize the aurora borealis. We will then discuss space weather tools in a more general sense, point out where the current capabilities and shortcomings are, and conclude with a look forward to what areas need improvement to facilitate better real-time forecasts.

  7. The Cosmic Dust Experiment of AIM

    Science.gov (United States)

    Poppe, A.; James, D.; Horanyi, M.

    2008-12-01

    The Cosmic Dust Experiment (CDE) onboard the Aeronomy of Ice in the Mesosphere (AIM) mission is a dust impact experiment designed to monitor the variability of the cosmic dust in ux. The instrument consists of fourteen permanently polarized thin plastic film sensors that generate an electrical signal when an impacting dust particle penetrates them. The total surface area is about 0.1 square meters and the detection threshold is about a micron in particle radius. The variability of these small grains is assumed to follow the variability of the dominant 100 micron radius particles, hence the measured flux can be used in correlation studies with various Noctilucent Cloud (NLC) activity indexes. CDE has been observing the cosmic dust influx since June 2007. In this talk, we present the first nine months of reduced data, focusing on the observed temporal and spatial variability of the dust influx. Data collected after February 2008 show increased levels of background noise and preliminary work on reducing this data will also be presented.

  8. Kristian Birkeland: The first space scientist

    Science.gov (United States)

    Egeland, Alv

    2009-12-01

    More than one hundred years ago Kristian Birkeland (1867-1917) first addressed the question as to why auroras appear overhead when the Earth's magnetic field is disturbed. He laid foundations for our current understanding of geomagnetism and polar auroras. For the first time cosmic phenomena were scaled and simulated in a laboratory. Birkeland's terrella experiments were ingenious. Even though the famous Lord Kelvin, in 1892, wrote that no matter passes between the Sun and the Earth, Birkeland's first auroral theory from 1896 is based on charged particle of solar origin, illustrated by the following quotation: "the auroras are formed by corpuscular rays drawn in from space, and coming from the sun". Thus, the year 1896 marks the founding of space plasma physics. His most enduring contribution to auroral physics was his recognition that field-aligned currents are needed to couple auroral phenomena in the upper atmosphere to interplanetary space. The existence of field-aligned currents was controversial and disputed vigorously among scientists for more than 50 years. During The Birkeland Symposium in 1967 it was unanimously proposed that field-aligned currents in space should be called "Birkeland currents", which was accepted by the International Union for Geomagnetism and Aeronomy. Today, plasma physicists strongly believe that many significant cosmic phenomena result from streams of Birkeland currents.

  9. 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.

  10. Stratospheric trace gas and aerosol profiles at McMurdo and South Pole stations

    Energy Technology Data Exchange (ETDEWEB)

    Hofmann, D.J. (Univ. of Wyoming, Laramie); Rosen, J.M.; Kjome, N.T.; Olson, G.L.; Schmeltekopf, A.L.; Goldan, P.D.; Winkler, R.H.

    1979-10-01

    During January 1979, we conducted balloon soundings in Antarctica to measure stratospheric trace gas and aerosol profiles. For the first time, we took trace gas samples at Amundsen-Scott (South Pole) Station. Four days earlier a similar experiment had been conducted at McMurdo Station. The samples, obtained by automatically opening evacuated stainless steel spheres at several altitudes, were returned to the United States and analyzed by gas chromatography at the Aeronomy Laboratory of the National Oceanic and Atmospheric Administration in Boulder, CO. The excellent agreement between McMurdo and South Pole data up to 20 kilometers suggests that trace gas concentrations in the polar regions are very uniform over a time period of at least four days and that measurements at either station are probably representative of the general antarctic profile. The same conclusion may be drawn from data on the fluorocarbons. These constituents also are very inert in the troposphere, but they undergo photodissociation in the stratosphere. As a result, their concentration drops off rapidly with altitude in the stratosphere. In addition to measuring trace gases, we again measured the stratospheric sulfate aerosol profile at McMurdo Station. Finally, we conducted a number of condensation nuclei soundings from the clean air facility at South Pole Station.

  11. 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...

  12. 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).

  13. Solar extreme ultraviolet sensor and advanced langmuir probe

    Science.gov (United States)

    Voronka, N. R.; Block, B. P.; Carignan, G. R.

    1992-01-01

    For more than two decades, the staff of the Space Physics Research Laboratory (SPRL) has collaborated with the Goddard Space Flight Center (GSFC) in the design and implementation of Langmuir probes (LP). This program of probe development under the direction of Larry Brace of GSFC has evolved methodically with innovations to: improve measurement precision, increase the speed of measurement, and reduce the weight, size, power consumption and data rate of the instrument. Under contract NAG5-419 these improvements were implemented and are what characterize the Advanced Langmuir Probe (ALP). Using data from the Langmuir Probe on the Pioneer Venus Orbiter, Brace and Walter Hoegy of GSFC demonstrated a novel method of monitoring the solar extreme ultraviolet (EUV) flux. This led to the idea of developing a sensor similar to a Langmuir probe specifically designed to measure solar EUV (SEUV) that uses a similar electronics package. Under this contract, a combined instrument package of the ALP and SEUV sensor was to be designed, constructed, and laboratory tested. Finally the instrument was to be flight tested as part of sounding rocket experiment to acquire the necessary data to validate this method for possible use in future earth and planetary aeronomy missions. The primary purpose of this contract was to develop the electronics hardware and software for this instrument, since the actual sensors were suppied by GSFC. Due to budget constraints, only a flight model was constructed. These electronics were tested and calibrated in the laboratory, and then the instrument was integrated into the rocket payload at Wallops Flight Facility where it underwent environmental testing. After instrument recalibration at SPRL, the payload was reintegrated and launched from the Poker Flat Research Range near Fairbanks Alaska. The payload was successfully recovered and after refurbishment underwent further testing and developing to improve its performance for future use.

  14. Assimilation of GIRO Data into a Real-Time IRI

    Science.gov (United States)

    Galkin, I. A.; Reinisch, B. W.; Huang, X.; Bilitza, D.

    2012-01-01

    Increasingly accurate and detailed global 3-D specification of the Earth's space plasma environment is required to further understand its intricate organization and behavior. For a long time space physics and aeronomy research has been data starved due to the great variety of natural time scales involved in the plasma phenomenology. We have started developing a new approach to the global ionospheric specification called Real-Time Assimilative Mapping (RTAM). The IRI-RTAM will use data from the Global Ionospheric Radio Observatory (GIRO) to smoothly transform International Reference Ionosphere's (IRI's) background empirical maps of the ionospheric characteristics to match the observations. Such empirical assimilative modeling will provide a high-resolution, global picture of the ionospheric response to various short-term events observed during periods of storm activity or the impact of gravity waves coupling the ionosphere to the lower atmosphere, including timelines of the vertical restructuring of the plasma distribution. It will also contribute to the challenging task of providing a rapid insight into the temporal and spatial space weather development using the real-time GIRO data streams. The new assimilation technique "updates" the IRI electron density distribution while preserving the overall integrity of IRI s typical ionospheric feature representations. The technique adjusts the coefficients of the spherical/diurnal expansions used by the CCIR and URSI-88 model to obtain the global sub-peak electron density distribution. The set of global corrected coefficients can be generated as frequently as every 15 min and easily disseminated using a single real-time RTAM server operated by GIRO.

  15. 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.

  16. Coordinated Remote Sounding and Local Measurements of Water Vapour in the Middle Atmosphere

    Science.gov (United States)

    Stegman, J.; Khaplanov, M.; Gumbel, J.; Witt, G.; Lautie, N.; Murtagh, D. P.; Kirkwood, S.; Stebel, K.; Schmidlin, F. J.; Fricke, K. H.; Blum, U.

    2003-12-01

    A complete snapshot of the water vapour distribution from the tropopause to the mesopause has been obtained from simultaneous in-situ rocket and balloon measurements conducted from Esrange on the morning of December 16, 2001 within the Odin validation programme. An active optical technique based on the dissociation of water molecules by Lyman alpha radiation generated by an on-board multicapillary Ly-alpha lamp and the subsequent detection of the optical emission from the resulting electronically excited OH radical produced outside the rocket shock front was used by the rocket borne payload Hygrosonde-II. A similar instrument was carried on the stratospheric SKERRIES balloon. A continuous vertical water vapour profile extending from 8 km to about 80 km has been compiled from the combined up- and downleg rocket measurement and the balloon sounding. Meteorological rockets (falling spheres) provided by NASA were flown before and after the Hygrosonde-II and SKERRIES flights to provide temperature, density and wind profiles in the upper stratosphere and mesosphere. Additional information on the density profile is available from the Rayleigh lidar at Esrange operated by Bonn University. The lidar provides a mean state profile in the stratosphere and mesosphere up to 95 km altitude for the Hygrosonde-II campaign period as well as profiles before and after the rocket and balloon flights. Meteorological data for the stratospheric analysis have also been obtained from the ECMWF analysis. An analysis of the obtained distribution of middle atmospheric water relates its details to the large-scale motions and the dynamics of the region (Khaplanov et al., Middle Atmospheric Water Vapour and Dynamics During the Hygrosonde-2 Campaign, 16th ESA-PAC Symposium, 2003). At the time of the Hygrosonde-II measurements the Odin satellite was configured in aeronomy mode and provided continuous water measurements using sub-mm limb sounding. A comparison of these remotely sensed measurements

  17. Co-ordinated Remote Sounding and Local Measurements of Water Vapour In The Middle Atmosphere

    Science.gov (United States)

    Stegman, J.; Hygrosonde-Ii Team; Odin Team

    A complete snapshot of the water vapour distribution from the tropopause to the mesopause has been obtained from simultaneous in-situ rocket and balloon measure- ments conducted from Esrange on the morning of December 16, 2001 within the Odin validation programme. An active optical technique based on the dissociation of wa- ter molecules by Lyman-alpha radiation generated by an on-board multicapillary Ly­ alpha lamp and the subsequent detection of the optical emission from the resulting electronically excited OH-radical produced outside the rocket shock front was used by the rocket borne payload Hygrosonde-II. A similar instrument was carried on the stratospheric SKERRIES balloon. Meteorological rockets (falling spheres) provided by NASA were flown before and after the Hygrosonde-II and SKERRIES flights to provide temperature, density and wind profiles in the upper stratosphere and mesosphere. Additional information on the density profile is available from the Rayleigh lidar at Esrange operated by Bonn University. The lidar provides a mean state profile in the stratosphere and mesosphere up to 95 km altitude for the Hygrosonde-II campaign period as well as profiles before and after the rocket and balloon flights. Water vapour measurements were conducted by Hygrosonde-II from 46 to 90 km on the upleg and from 90 to 23 km on the downleg. From these measurements we expect to be able to retrieve a water vapour profile extending from 23 km to about 80 km. SKERRIES reached a floating level of 26 km and provided measurements from 8 km to 26 km on both up- and downleg. At the time of the Hygrosonde-II measurements the Odin satellite was configured in aeronomy mode and provided continuous water measurements using sub-mm limb sounding. A comparison of these remotely sensed measurements during Odin passes over Esrange with the local Hygrosonde-II/SKERRIES measurements will be pre- sented.

  18. Features of the ELF Electromagnetic Wave Propagation in the Homogeneous Ionosphere

    Science.gov (United States)

    Sergeev, Igor

    The quasi-stationary Maxwell equations of the gyrotropic waves have been examined. In con-trast to the approach used in the other papers (Sorokin et al., 2009; Sorokin et al., 2006; Sergeev and Sorokin, 2005) the general form of the electromagnetic equation of the gyrotropic waves has been considered. The dispersion equation analysis shows that attenuation of one of the mode tends to zero in the perpendicular to the magnetic field direction while along this direction the attenuation is finite. Basing on this feature we can suppose that low frequency electromagnetic fluctuations tend to expand along the magnetic field. It forms in the iono-sphere long areas with invariable direction of the electric field and current and weakly variable magnitude of these parameters. To check this conclusion the direct problem of the evolution of an electromagnetic fluctuation has been solved numerically. The results show that spherically symmetric fluctuation expands along the magnetic field lines by 5-30 times while in some cases the widening is fully absent. References Sorokin V.M., Sergeev I.Yu., Pokhotelov O.A. Low latitude gyrotropic waves in a finite thickness ionospheric conducting layer. Journal of Atmospheric and Solar-Terrestrial Physics, V. 71, P. 175-179, 2009. Sorokin V.M., Sergeev I.Yu., and Yaschenko A.K. Electromagnetic field generation by explosion in the ionosphere. Advances in Space Research, V. 38, No. 11, P. 2511-2515, 2006. Sergeev I.Yu. and Sorokin V.M. Mechanism of the LF Narrow-Band Spectrum Electromagnetic Disturbance Formation Observed on the Earth Surface during Spacecraft Launches. Geomag-netism and Aeronomy, Vol. 45, No. 4, P. 520-525, 2005.

  19. 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.

  20. Opportunities in Heliophysics

    Science.gov (United States)

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

    2014-12-01

    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. 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 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.

  1. Boundary layer structure over the ocean observed by LEANDRE 1 during a tramontane event

    Science.gov (United States)

    Flamant, C.; Pelon, J.; Flamant, P.; Durand, P.

    1992-01-01

    A new airborne backscatter lidar, has been developed by CNRS (Service d'Aeronomie, (SA) Laboratoire de Meteorologie Dynamique (LMD) and the Institut des Sciences de 1'Univers) in the frame of the LEANDRE research program. It has been qualified on board the ARAT in autumn 1989 and spring 1990 and was involved in its first cooperative campaign during PYREX in October and November 1990. During this campaign, lidar observations of the perturbations induced on tropospheric flow and boundary layer structure were performed, and results are presented. A large number of experiments were performed, for synoptic situation description (meteorological radiosoundings, constant level balloons) and local flow analysis (aircrafts, radars, sodars). For the first time in such an experiment, a lidar has been flown on a research aircraft to perform altitude resolved observations of these perturbations, and we will present here results obtained for deflected flow structure. In the presence of a synoptic northerly flow, part of it is deflected to the east by the Pyrenees, and accelerated over the Mediterranean by the mountain surroundings. In this case, a low level wind is generated (the Tramontane) bringing cold and dry air over the Mediterranean Sea. As the sea is still at a warm temperature in November (around 17 degrees), an Internal Marine Boundary Layer rapidly grows over the first tens of kilometers and stabilizes at about 1 km depth, corresponding to an altitude just below the Lifting Condensation Level. The whole Marine Atmospheric Boundary Layer (MABL) is characterized by highly turbulent motions bringing large humid particles from the surface up to its top. The lidar signal due to scattering by these particles is then representative of the turbulent kinetic energy in this layer.

  2. 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.

  3. Nonlinear Farley-Buneman instability with Dust Impurities.

    Science.gov (United States)

    Atamaniuk, B.; Volokitin, A. S.

    2009-04-01

    The regimes of nonlinear stabilization of instability of low frequency waves in magnetized, weakly ionized and inhomogeneous ionospheric dusty plasma are considered. In the lower ionosphere in the E--region, a complex process transforms wind energy into currents creating the E--region electrojet. If these currents exceed a certain critical amplitude, a streaming instability called the Farley--Buneman or a collisional two-stream instability develops. When the number of cooperating waves remains small due to a competition of processes of their instability and attenuation, the turbulence appears in the result of their stochastic behavior. Then even system with finite number of interacting waves can realize a turbulent state in active media. At conditions when electrons are magnetized and characteristic time of density oscillations exceed the rate of electron ion collisions and electron dust collision the drift of electrons perpendicular to magnetic field is the main motion. Consequently, the main nonlinearity appears in result of convection of a density perturbation in one wave by another wave in the perpendicular to magnetic field and mathematically is expressed in a specific vector form The strong collisional damping of waves allow to assume that a typical perturbed state of plasma can be described as finite set of interacting waves. This allow to avoid difficulties of 3D simulations and to make full study of nonlinear stabilization and influence of the dust component in the conditions when the number of interacting waves keeps small by the strong competition of processes wave damping and instabilities Keywords: Dusty Plasmas, Farley-Buneman Instability, Nonlinear Stabilization. REFERENCES 1. M. Oppenheim and N. Otani, Geophysical Research Letters, 22, pp. 353-356, 1995. 2. A.V. Volosevich and C.V. Meister, Int. Journal of Geomagnetism and aeronomy, 3 pp.151-156, 2002 3. A. S. Volokitin and B. Atamaniuk, Reduced nonlinear description of Farley-Buneman instability

  4. CN, NH2, and dust in the atmosphere of comet C/1999 J3 (LINEAR)

    Science.gov (United States)

    Korsun, P. P.; Jockers, K.

    2002-01-01

    Comet C/1999 J3 (LINEAR) was observed with 2 m telescope of the Pik Terskol Observatory on September 19, 1999. Narrow-band CCD images of the CN, NH2, and dust atmospheres were recorded with the Two-Channel focal reducer of the Max-Plank-Institute for Aeronomy. The distributions of the CN and NH2 molecules in the comet atmosphere were fitted with a Monte Carlo model. For the CN atmosphere the best agreement between observed and calculated surface profiles was reached with the CN photodissociation lifetime tau (CN)=1.5*E5 s and with the parent photodissociation lifetime tau (CNparent)=3.2*E4 s. This result indicates that HCN is the main source of the CN radicals in the atmosphere of comet C/1999 J3 (LINEAR). Regarding the NH2 radicals, there is no doubt that NH3 is the dominant source of this species in the comet atmosphere. The lifetimes tau (NH2)=1.0*E5 s for NH2 and tau (NH2 parent)=5.0*E3 s for its parent are close to theoretical calculations. The gas-production rates of CN, Q(CN)=3.8 *E25 mol s-1, and NH2, Q(NH2)=6.9*E25 mol s-1 have also been determined. The appearance of the comet and the obtained data show that the comet is a gaseous one. The Afrho values are 21.6 cm for the blue spectral window and 23.4 cm for the red one. The normalized spectral gradient of the cometary dust is low, 4.0% per 1000 Å. The ratio log((Afrho )443/Q(CN)) = -24.25 indicates a very low dust to gas ratio as well.

  5. Dust tail of the distant comet C/1999 J2 (Skiff)

    Science.gov (United States)

    Korsun, P. P.; Chörny, G. F.

    2003-11-01

    CCD observations of comet C/1999 J2 (Skiff) were made at the Pik Terskol Observatory on September 15, 1999. The 2-m telescope equipped with the two-channel focal reducer of the Max-Plank-Institute for Aeronomy was used to study the cometary environment. In spite of the large heliocentric distance, 7.24 AU, a straight dust tail with fairly well defined boundaries was recorded. These data provide an opportunity to study the peculiarity of dust, that is not driven by water vapor. To fit the dust tail, a Monte Carlo model was developed. We trace the trajectories of about 107 sample grains to construct the detailed brightness distribution in the comet tail. The simulated isophote field and the observed one agree very well. In our model we also take into account the heliocentric dependence of the dust production rate and ejection velocity, and the dust ejection anisotropy. To transform the particle population to brightness in the modelled tail we calculate the scattering cross section of a separate particle using Mie theory. The age, ejection velocity, dust size distribution, minimum and maximum size of the involved dust particles have been derived from the model giving the best fit. The intensity map is in agreement with a flow of the slowly travelling icy grains. It has been determined that the age of the dust tail of comet C/1999 J2 (Skiff) was, at the moment of the observations, about 540 days and that the main reason for its appearance is likely phase transition from amorphous to crystalline water ice activated at the heliocentric distance of 8.6 AU.

  6. Intercomparison of Odin/SMR ozone measurements with MIPAS and balloon sonde data

    Energy Technology Data Exchange (ETDEWEB)

    Jones, A.; Murtagh, D.; Urban, J.; Eriksson, P.; Rosevall, J. [Chalmers Univ. of Technology, Goteborg (Sweden). Dept. of Radio and Space Science

    2007-11-15

    The Odin satellite was launched into orbit in February 2001 as a joint initiative of Sweden, Canada, France and Finland to conduct research in aeronomy and astronomy. An optical spectrograph and infra-red imager system (OSIRIS) and an sub-millimetre radiometer (SMR) are onboard the satellite. Three versions (v1.2, v2.0 and v2.1)of global stratigraphic ozone data collected from the SMR were compared to Michelson Interferometer for Passive Atmospheric Soundings (MIPAS) ozone data and to ozone balloon sonde data collected in 2003. The purpose of this study was to evaluate the quality of the Odin/SMR ozone data which has been the focus of various stratospheric ozone studies. The v2.1 version showed the smallest systematic differences when compared to coincident MIPAS and sonde data. Between 17 and 55 km, v2.1 values agreed with MIPAS within 10 per cent (a maximum of 0.42 ppmv), while comparisons to sonde measurements showed an agreement of about 5 to 10 per cent between 22 and 35 km (less than 0.5 ppmv below 33 km). Tropical latitudes below 35 km presented the largest absolute systematic differences between v2.1 and sonde coincidences, where Odin/SMR was typically lower by about 0.9 (more than 10 per cent difference) at about 30 km. A comparison of the previous 2 Odin/SMR versions revealed considerably larger systematic differences, particularly at the higher and lower stratospheric altitudes. It was therefore suggested that scientific studies should rely on version v2.1 of Odin/SMR ozone data. 23 refs, 1 tab., 5 figs.

  7. 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.

  8. Multimodel comparison of the ionosphere variability during the 2009 sudden stratosphere warming

    Science.gov (United States)

    Pedatella, N. M.; Fang, T.-W.; Jin, H.; Sassi, F.; Schmidt, H.; Chau, J. L.; Siddiqui, T. A.; Goncharenko, L.

    2016-07-01

    A comparison of different model simulations of the ionosphere variability during the 2009 sudden stratosphere warming (SSW) is presented. The focus is on the equatorial and low-latitude ionosphere simulated by the Ground-to-topside model of the Atmosphere and Ionosphere for Aeronomy (GAIA), Whole Atmosphere Model plus Global Ionosphere Plasmasphere (WAM+GIP), and Whole Atmosphere Community Climate Model eXtended version plus Thermosphere-Ionosphere-Mesosphere-Electrodynamics General Circulation Model (WACCMX+TIMEGCM). The simulations are compared with observations of the equatorial vertical plasma drift in the American and Indian longitude sectors, zonal mean F region peak density (NmF2) from the Constellation Observing System for Meteorology, Ionosphere, and Climate (COSMIC) satellites, and ground-based Global Positioning System (GPS) total electron content (TEC) at 75°W. The model simulations all reproduce the observed morning enhancement and afternoon decrease in the vertical plasma drift, as well as the progression of the anomalies toward later local times over the course of several days. However, notable discrepancies among the simulations are seen in terms of the magnitude of the drift perturbations, and rate of the local time shift. Comparison of the electron densities further reveals that although many of the broad features of the ionosphere variability are captured by the simulations, there are significant differences among the different model simulations, as well as between the simulations and observations. Additional simulations are performed where the neutral atmospheres from four different whole atmosphere models (GAIA, HAMMONIA (Hamburg Model of the Neutral and Ionized Atmosphere), WAM, and WACCMX) provide the lower atmospheric forcing in the TIME-GCM. These simulations demonstrate that different neutral atmospheres, in particular, differences in the solar migrating semidiurnal tide, are partly responsible for the differences in the simulated

  9. Version 1.3 AIM SOFIE measured methane (CH4): Validation and seasonal climatology

    Science.gov (United States)

    Rong, P. P.; Russell, J. M.; Marshall, B. T.; Siskind, D. E.; Hervig, M. E.; Gordley, L. L.; Bernath, P. F.; Walker, K. A.

    2016-11-01

    The V1.3 methane (CH4) measured by the Aeronomy of Ice in the Mesosphere (AIM) Solar Occultation for Ice Experiment (SOFIE) instrument is validated in the vertical range of 25-70 km. The random error for SOFIE CH4 is 0.1-1% up to 50 km and degrades to 9% at ˜ 70 km. The systematic error remains at 4% throughout the stratosphere and lower mesosphere. Comparisons with CH4 data taken by the SCISAT Atmospheric Chemistry Experiment-Fourier Transform Spectrometer (ACE-FTS) and the Envisat Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) show an agreement within 15% in the altitude range 30-60 km. Below 25 km SOFIE CH4 is systematically higher (≥20%), while above 65 km it is lower by a similar percentage. The sign change from the positive to negative bias occurs between 55 km and 60 km (or 40 km and 45 km) in the Northern (or Southern) Hemisphere. Methane, H2O, and 2CH4 + H2O yearly differences from their values in 2009 are examined using SOFIE and MIPAS CH4 and the Aura Microwave Limb Sounder (MLS) measured H2O. It is concluded that 2CH4 + H2O is conserved with altitude up to an upper limit between 35 km and 50 km depending on the season. In summer this altitude is higher. In the Northern Hemisphere the difference relative to 2009 is the largest in late spring and the established difference prevails throughout summer and fall, suggesting that summer and fall are dynamically quiet. In both hemispheres during winter there are disturbances (with a period of 1 month) that travel downward throughout the stratosphere with a speed similar to the winter descent.

  10. Persistent longitudinal variations in 8 years of CIPS/AIM polar mesospheric clouds

    Science.gov (United States)

    Liu, Xiao; Yue, Jia; Xu, Jiyao; Yuan, Wei; Russell, James M.; Hervig, M. E.; Nakamura, Takuji

    2016-07-01

    The Cloud Imaging and Particle Size (CIPS) instrument on the Aeronomy of Ice in the Mesosphere (AIM) satellite provides an opportunity to study the longitudinal variation in polar mesospheric cloud (PMC). We examined the longitudinal variation in PMC albedo using 8 years (2007-2014) of observations from the CIPS instrument. The results show that the PMC albedo in the Southern Hemisphere (SH), especially in the latitude band of 80°S-85°S, is persistently low ( 65% relative to the rest of the hemisphere) within 60°W to 150°W longitude. In the Northern Hemisphere (NH), however, PMC albedo is found to be relatively zonally asymmetry. Harmonic analyses show that the persistent longitudinal variation in the SH PMC albedo is due to zonal wave numbers 1 through 4 (WN1-WN4) processes with minima in the longitude range of 60°W-150°W. The influence of temperature and H2O on the longitudinal variation of the PMC albedo is discussed based on results obtained using a simple 0-D PMC model and temperature from the Microwave Limb Sounder (MLS) and the Sounding of the Atmosphere with Broadband Emission Radiometry (SABER) and H2O from MLS. The modeled region of low ice mass in the SH is generally consistent with that of low PMC albedo seen in CIPS. Tidal analyses using the SABER temperatures indicate that the nonmigrating semidiurnal tides with modes of S0, W1, and E1 might be the main drivers of the persistent longitudinal variations of PMC albedo in the SH. Nonmigrating tides are much weaker in the NH and consistent with the observed lack of longitudinal variability in PMC albedo.

  11. 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.

  12. Mid-latitude mesospheric clouds and their environment from SOFIE observations

    Science.gov (United States)

    Hervig, Mark E.; Gerding, Michael; Stevens, Michael H.; Stockwell, Robert; Bailey, Scott M.; Russell, James M.; Stober, Gunter

    2016-11-01

    Observations from the Solar Occultation For Ice Experiment (SOFIE) on the Aeronomy of Ice in the Mesosphere (AIM) satellite are used to examine noctilucent clouds (NLC) and their environment at middle latitudes ( 56°N and 52°S). Because SOFIE is uniquely capable of measuring NLC, water vapor, and temperature simultaneously, the local cloud environment can be specified to examine what controls their formation at mid-latitudes. Compared to higher latitudes, mid-latitude NLCs are less frequent and have lower ice mass density, by roughly a factor of five. Compared to higher latitudes at NLC heights, mid-latitude water vapor is only 12% lower while temperatures are more than 10 K higher. As a result the reduced NLC mass and frequency at mid-latitudes can be attributed primarily to temperature. Middle and high latitude NLCs contain a similar amount of meteoric smoke, which was not anticipated because smoke abundance increases towards the equator in summer. SOFIE indicates that mid-latitude NLCs may or may not be associated with supersaturation with respect to ice. It is speculated that this situation is due in part to SOFIE uncertainties related to the limb measurement geometry combined with the non-uniform nature of NLCs. SOFIE is compared with concurrent NLC, temperature, and wind observations from Kühlungsborn, Germany (54°N) during the 2015 summer. The results indicate good agreement in temperature and NLC occurrence frequency, backscatter, and height. SOFIE indicates that NLCs were less frequent over Europe during 2015 compared to other longitudes, in contrast to previous years at higher latitudes that showed no clear longitude dependence. Comparisons of SOFIE and the Solar Backscatter Ultraviolet (SBUV) indicate good agreement in average ice water column (IWC), although differences in occurrence frequency were often large.

  13. 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.

  14. First imaging and identification of a noctilucent cloud from multiple sites in Hokkaido (43.2-44.4°N), Japan

    Science.gov (United States)

    Suzuki, Hidehiko; Sakanoi, Kazuyo; Nishitani, Nozomu; Ogawa, Tadahiko; Ejiri, Mitsumu K.; Kubota, Minoru; Kinoshita, Takenori; Murayama, Yasuhiro; Fujiyoshi, Yasushi

    2016-11-01

    Simultaneous imaging observations of a noctilucent cloud (NLC) from five sites in Hokkaido, Japan (43.17-45.36°N), were successfully carried out using digital cameras in the early hours of the morning (around 02:00 LST) on June 21, 2015. This is the first NLC event that has been captured from multiple sites in Japan. The simultaneous images obtained from multiple sites made it possible to calculate the exact altitude (=83.9 ± 0.1 km) and spatial distribution (47.5-50.0°N and 143.0-147.5°E) of the NLC by triangulation and image correlation methods. Based on a comparison of atmospheric parameters of the upper mesosphere provided by satellites and a middle-frequency (MF) radar in northern Hokkaido (Wakkanai) with the cloud distribution obtained from the Aeronomy of Ice in the Mesosphere satellite, this particular event is considered to be the result of southward advection of the NLC from a higher-latitude (i.e., colder) region. Anomalies in the upper mesospheric temperature of the northern hemispheric summer in 2015 were examined using AURA satellite data, because this is the first NLC event that has been identified in Japan. However, no remarkable temperature variations relative to other years were found in upper mesosphere. Based on a comparison between the NLC period and the record of sky conditions archived by the Japan Meteorological Agency, a high percentage of cloud (especially low-level) cover during the summer in Hokkaido cannot be ruled out as a possible reason why the NLC had not previously been sighted in Hokkaido.[Figure not available: see fulltext.

  15. Virtualization research on IGRF 10(International Geomagnetic Reference Field)model%IGRF国际地磁参考场模型可视化研究

    Institute of Scientific and Technical Information of China (English)

    王丹; 彭丰林; 马麦宁; 袁晓茹; 白春华; 孙立江

    2009-01-01

    IGRF(International Geomagnetic Reference Field)即全球地磁参考模型,是由国际地磁和高空物理学联合会(International Association of Geomagnetism and Aeronomy)发布的一系列关于地球主磁场及其年变率的数学模型.作为科学研究和工程应用的背景场、参考场广泛用于地球深部、地壳、电离层和磁层的研究.本文以最新的一代至第10代IGRF模型为基础,以Google公司开发的虚拟三维地球软件Google Earth为载体,进行了国际地磁参考场可视化研究.生成了一系列地磁要素的KML文件.并发布在世界数据中心中国地球物理学科中心的网站上,用户通过下载并打开这些文件就可以在Google Earth上查看到中国地区地磁场7个分量的可视化结果.本文所使用的方法也同样适用于第一代至第九代IGRF模型以及今后将要建立的IGRF模型.

  16. 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.

  17. Ground testing and flight demonstration of charge management of insulated test masses using UV-LED electron photoemission

    Science.gov (United States)

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

    2016-12-01

    The UV-LED mission demonstrates the precise control of the potential of electrically isolated test masses. Test mass charge control is essential for the operation of space accelerometers and drag-free sensors which are at the core of geodesy, aeronomy and precision navigation missions as well as gravitational wave experiments and 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 UVLEDs operating at 255 nm are superior to Hg lamps because of their smaller size, lower power draw, higher dynamic range, and higher control authority. We show laboratory data demonstrating the effectiveness and survivability of the UV-LED devices and performance of the charge management system. We also show flight data from a small satellite experiment that was one of the payloads on KACST’s SaudiSat-4 mission that demonstrates ‘AC charge control’ (UV-LEDs and bias are AC modulated with adjustable relative phase) between a spherical test mass and its housing. The result of the mission brings the UV-LED device Technology Readiness Level (TRL) to TRL-9 and the charge management system to TRL-7. We demonstrate the ability to control the test mass potential on an 89 mm diameter spherical test mass over a 20 mm gap in a drag-free system configuration, with potential measured using an ultra-high impedance contact probe. Finally, the key electrical and optical characteristics of the UV-LEDs showed less than 7.5% change in performance after 12 months in orbit.

  18. The SMM UV observations of Active Region 5395

    Science.gov (United States)

    Drake, Stephen A.; Gurman, Joseph B.

    1989-01-01

    The Ultraviolet Spectrometer and Polarimeter (UVSP) on the Solar Maximum Mission (SMM) spacecraft was used extensively to study the spatial morphology and time variability of solar active regions in the far UV (at approx. wavelength of 1370 A) since July 1985. The normal spatial resolution of UVSP observations in this 2nd-order mode is 10 sec., and the highest temporal resolution is 64 milliseconds. To make a full-field, 4 min. by 4 min. image this wavelength using 5 sec. raster steps takes about 3 minutes. UVSP can also make observations of the Sun at approx. wavelength of 2790 with 3 sec. spatial resolution when operated in its 1st-order mode; a full-field image at this wavelength (a so-called SNEW image) takes about 8 minutes. UVSP made thousands of observations (mostly in 2nd-order) of AR 5395 during its transit across the visible solar hemisphere (from 7 to 19 March, inclusive). During this period, UVSP's duty cycle for observing AR 5395 was roughly 40 percent, with the remaining 60 percent of the time being fairly evenly divided between aeronomy studies of the Earth's atmosphere and dead time due to Earth occultation of the Sun. UVSP observed many of the flares tagged to AR 5395, including 26 GOES M-level flares and 3 X-level flares, one of which produced so much UV emission that the safety software of UVSP turned off the detector to avoid damage due to saturation. Images and light curves of some of the more spectacular of the AR 5395 events are presented.

  19. Ionospheric Data Assimilation from a Data Provider's Perspective

    Science.gov (United States)

    Schaefer, R. K.; Paxton, L. J.; Bust, G.; Zhang, Y.; Romeo, G.; Comberiate, J.; Gelinas, L. J.

    2014-12-01

    The Ionosphere/Thermosphere system is a very dynamic and complex medium to model. Given sufficient data and proper data handling, assimilative models can give a good representation of this system. One good dataset for this purpose comes from UV imagers on spacecraft. In particular, the Oxygen recombination emission (135.6 nm) and the Nitrogen Lyman-Birge Hopfield band (both 140-150 nm and 165-180 nm) are being collected by instruments on the NASA TIMED/GUVI and DMSP/SSUSI instruments. Similar UV data will also be available in the future from the ICON and GOLD missions. Currently, the Air Force is using the oxygen emission to infer ionospheric electron densities in the USU GAIM model for ionospheric forecasts. We have also been integrating data for the IDA4D model assimilation (Bust et al, 2007). As the data product designer for these UV products, we have an unique perspective on issues related to assimilating this data. These issues concern model resolution scales (Schunk, et al, 2011), filtering of noisy data, and handling of second order effects. We will discuss our experience with these issues and point out some future directions for assimilation of UV data. Bust, G., Crowley, G., Curtis, N., Reynolds, A., Paxton, L., Coker, C., Bernhardt, P. "IDA4D - a new ionospheric imaging algorithm using non-linear ground-based and spaced- based data sources", American Geophysical Union, Fall Meeting 2007, abstract #SA11B-06. Schunk, R.W., Scherliess, L., and Thompson, D.C., 2011 "Ionospheric Data Assimilation: Problems Associated with Missing Physics", Aeronomy of the Earth's Atmosphere and Ionosphere. IAGA Special Sopron Book Series Volume 2, pp 437-442.

  20. 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.

  1. 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

  2. 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

  3. The Hundred Year Hunt for the Red Sprite

    Science.gov (United States)

    Lyons, W. A.; Schmidt, M.

    2003-12-01

    This presentation reviews an NSF Informal Science Education project directed by the PO of an ongoing NSF Physical Meteorology/Aeronomy-sponsored research program on red sprites. For over 100 years, anecdotal reports and citations in the literature have persisted of strange luminous apparitions occurring high above thunderstorms. They were long discounted by the scientific community - until 1989, when by pure chance, a video revealed two giant pillars of light extending tens of kilometers above a thunderstorm. Since then, thousands of events, now called sprites, have been imaged, many by the PI. Mesospheric sprites, at 40 to 90 km altitude, are induced by lightning discharges having highly unusual characteristics. Science is now gradually unraveling the nature of the giant lightning discharges which spawn sprites. In the process we have found even more unusual electrical discharges above thunderstorms, suggesting that many new discoveries await to be made. We produced and are distributing a planetarium DVD/video program (42 minutes length) entitled, "The Hundred Year Hunt for the Red Sprite." It documents the application of the scientific method to unraveling this century old mystery surrounding strange lights in the night sky. We also contrasted this story of discovery to the pseudo-science prevalent today in topics such as UFOs. With distribution to numerous planetaria and science centers, we believe over 200,000 persons will eventually view this program (which has won three major video production awards). Our long term goal is to inspire planetarium visitors to undertake their own self-directed learning programs. A companion educational web site (www.Sky-Fire.TV) allows students and adults sufficiently motivated by the planetarium experience to further investigate sprites and related basic science topics. The highly interactive web site challenges visitors to test their knowledge of sprites and lightning by participating in an on-line 20 question quiz game, which

  4. Development of a novel sweeping Langmuir probe instrument for monitoring the upper ionosphere on board a pico-satellite

    Science.gov (United States)

    Ranvier, Sylvain; De Keyser, Johan; Cardoen, Pepijn; Pieroux, Didier

    2014-05-01

    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 Belgian Institute for Space Aeronomy. PICASSO was initiated to join the QB50 project as scientific in-orbit demonstrator. The sweeping Langmuir probe (SLP) instrument 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 1e6/m³ at high latitude and high altitude up to 1e12/m³ at low/mid latitude and low altitude. The electron temperature is expected to lie between approximately 1000 K and 3000 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. 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, and 5) ionospheric dynamics via coordinated observations with EISCAT's heating radar. To achieve the scientific objectives described above, the instrument includes four thin cylindrical probes whose electrical potential is swept in such a way that both plasma density and electron temperature can be derived. In addition, since at least two probes will be out of the spacecraft's wake at any given time, differential measurements can be performed to increase the accuracy. 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

  5. The physical principles of the combined ELF/VLF method for single-station global location of lightning

    Science.gov (United States)

    Mushtak, V.; Price, C.; Williams, E.

    errors. These effects are simulated both qualitatively and quantitatively on the basis of classical geometrical optics (Snell's law) as well as by means of the two-dimensional telegraph equation method for calculating ELF fields in a non-uniform waveguide (Kirillov et al., 1997). REFERENCES: Kemp, D.T., Jones, D.Ll., 1971. Journal of Atmospheric and Terrestrial Physics 33,567-572. Boccippio, D.J. et al., 1998. Journal of Atmospheric and Solar-Terrestrial Physics 60,701-712. Price, C., Mustafa, A., Lyons, W., Nelson, T., 2002. Geophysical Research Letters 29, 1.1-1.4. Kirillov, V.V., Kopeykin, V.N., Mushtak, V.C., 1997. Geomagnetism and Aeronomy 37, 114-120 [in Russian].

  6. Calculation of the satellite "Sich-1M" orientation on onboard magnetometric measurements

    Science.gov (United States)

    Suhorukov, A.; Kozak, L.

    2005-04-01

    The satellite "Sich-1M" was launched on 24 December 2004. It came out onto the elliptic orbit with the perigee height near 280 km except planned earlier higher near circle orbit. In addition, the satellite has gotten a non-planned rotation (about 2 rotations per turn). Later the gravitational beam had been pulled out from the satellite which partly stabilized it. A rotation of the satellite was superseded by its oscillation with a period near 2-4 swings per turn and amplitude 50 degrees. The oscillations have an unstable character. Rotations and oscillations of the satellite set inessential limitations on realization of scientific tasks of the project "Variant" because there is a possibility to determine the satellite orientation for a given time moment with the help of measurements of ferrosonde magnetometer FZM or onboard magnetometer. The device FZM measures three components of magnetic field Bx, By, Bz of the Earth in coordinate system of the satellite. To determine the satellite orientation we have used the fact that each of the component of the magnetic field at the present time moment is a function of geographical coordinates of the satellite (latitude, longitude, height over sea level), its orientation and components of a vector of Earth magnetic field in this point, calculated from magnetosphere model. Thus, having direct satellite measurements of Bx, By, Bz at given time moment in given point, orbital elements and position of the satellite on the orbit and using the standard model of Earth's magnetosphere one can calculate the satellite orientation as function of time. For the calculation we have used the magnetosphere model "The International Geomagnetic Reference Field" (IGRF) which empirically calculates the components of magnetic field of the Earth and is recommended for scientific investigations by International Association of Geomagnetism and Aeronomy (IAGA). Coefficients of IGRF model are based on accessible information sources including

  7. 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.

  8. 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

  9. 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

  10. 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

  11. 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

  12. 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

  13. The Influence of Dust on the Farley-Buneman instability. Nonlinear regimes.

    Science.gov (United States)

    Atamaniuk, Barbara

    , pp. 273, 1996 3. A. V. Volosevich and C.-V. Meister, Coherent nonlinear interaction of waves in collisional ionospheric plasma, INTERNATIONAL JOURNAL OF GEOMAGNETISM AND AERONOMY, 3, pp. 151-156, 2002 4. A. S. Volokitin and B. Atamaniuk, Farley-Buneman Instability. Nonlinear regimes. Plasma Phys. Reports., 2007, in press 5. A. S. Volokitin and B. Atamaniuk, Reduced nonlinear description of Farley-Buneman instability. AIP Conference Proceedings Volume 974 in press

  14. 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.

  15. High Energy Electrons and Gamma Rays from the ATIC-2 Balloon Flight

    Science.gov (United States)

    Isbert, J. B.; ATIC Collaboration

    2004-08-01

    ) Max Plank Institute fur Aeronomie, Lindau,Germany (7) Purple Mountain Observatory, Chinese Academy of Sciences (CAS), China.

  16. 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

  17. 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。

  18. 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

  19. The ASSET intercomparison of stratosphere and lower mesosphere humidity analyses

    Directory of Open Access Journals (Sweden)

    H. E. Thornton

    2009-02-01

    Full Text Available This paper presents results from the first detailed intercomparison of stratosphere-lower mesosphere water vapour analyses; it builds on earlier results from the EU funded framework V "Assimilation of ENVISAT Data" (ASSET project. Stratospheric water vapour plays an important role in many key atmospheric processes and therefore an improved understanding of its daily variability is desirable. With the availability of high resolution, good quality Michelson Interferometer for Passive Atmospheric Sounding (MIPAS water vapour profiles, the ability of four different atmospheric models to assimilate these data is tested. MIPAS data have been assimilated over September 2003 into the models of the European Centre for Medium Range Weather Forecasts (ECMWF, the Belgian Institute for Space and Aeronomy (BIRA-IASB, the French Service d'Aéronomie (SA-IPSL and the UK Met Office. The resultant middle atmosphere humidity analyses are compared against independent satellite data from the Halogen Occultation Experiment (HALOE, the Polar Ozone and Aerosol Measurement (POAM III and the Stratospheric Aerosol and Gas Experiment (SAGE II. The MIPAS water vapour profiles are generally well assimilated in the ECMWF, BIRA-IASB and SA systems, producing stratosphere-mesosphere water vapour fields where the main features compare favourably with the independent observations. However, the models are less capable of assimilating the MIPAS data where water vapour values are locally extreme or in regions of strong humidity gradients, such as the southern hemisphere lower stratosphere polar vortex. Differences in the analyses can be attributed to the choice of humidity control variable, how the background error covariance matrix is generated, the model resolution and its complexity, the degree of quality control of the observations and the use of observations near the model boundaries. Due to the poor performance of the Met Office analyses the results are not included in

  20. 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

  1. 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

  2. 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

  3. 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

  4. 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.

  5. To Boldly Go: America's Next Era in Space. The Plasma Universe

    Science.gov (United States)

    2004-01-01

    Dr. France Cordova, NASA's Chief Scientist, chaired this, the eighth seminar in the Administrator's Seminar Series. She introduced the NASA Administrator, Daniel S. Goldin, who, in turn, introduced the subject of plasma. Plasma, an ionized gas, is a function of temperature and density. We ve learned that, at Jupiter, the radiation is dense. But, Goldin asked, what else do we know? Dr. Cordova then introduced Dr. James Van Allen, for whom the Van Allen radiation belt was named. Dr. Van Allen, a member of the University of Iowa faculty, discussed the growing interest in practical applications of space physics, including radiation fields and particles, plasmas and ionospheres. He listed a hierarchy of magnetic fields, beginning at the top, as pulsars, the Sun, planets, interplanetary medium, and interstellar medium. He pointed out that we have investigated eight of the nine known planets,. He listed three basic energy sources as 1) kinetic energy from flowing plasma such as constitutional solar wind or interstellar wind; 2) rotational energy of the planet, and 3) orbital energy of satellites. He believes there are seven sources of energetic particles and five potential places where particles may go. The next speaker, Dr. Ian Axford of New Zealand, has been associated with the Max Planck Institut fuer Aeronomie and plasma physics. He has studied solar and galactic winds and clusters of galaxies of which there are several thousand. He believes that the solar wind temperature is in the millions of degrees. The final speaker was Dr. Roger Blanford of the California Institute of Technology. He classified extreme plasmas as lab plasmas and cosmic plasmas. Cosmic plasmas are from supernovae remnants. These have supplied us with heavy elements and may come via a shock front of 10(sup 15) electron volts. To understand the physics of plasma, one must learn about x-rays, the maximum energy of acceleration by supernova remnants, particle acceleration and composition of cosmic

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

    Science.gov (United States)

    Olofsson, A. O. H.; Persson, C. M.; Koning, N.; Bergman, P.; Bernath, P. F.; Black, J. H.; Frisk, U.; Geppert, W.; Hasegawa, T. I.; Hjalmarson, Å.; Kwok, S.; Larsson, B.; Lecacheux, A.; Nummelin, A.; Olberg, M.; Sandqvist, Aa.; Wirström, E. S.

    2007-12-01

    Aims:Spectral line surveys are useful since they allow identification of new molecules and new lines in uniformly calibrated data sets. The subsequent multi-transition analysis will provide improved knowledge of molecular abundances, cloud temperatures and densities, and may also reveal previously unsuspected blends of molecular lines, which otherwise may lead to erroneous conclusions. Nonetheless, large portions of the sub-millimetre spectral regime remain unexplored due to severe absorptions by H{2}O and O{2} 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. Methods: 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 h each). An on-source integration time of 20 h was achieved for most bands. The entire campaign consumed 1100 orbits, each containing one hour of serviceable astro-observation. Results: We identified 280 spectral lines from 38 known interstellar molecules (including isotopologues) having intensities in the range 80 to 0.05 K. An additional 64 weak lines remain unidentified. Apart from the ground state rotational 1{1,0}-1{0,1} transitions of ortho-H{2}O, H{2}18O and H{2}17O, the high energy 6{2,4}-7{1,7} line of para-H{2}O (Eu=867 K) and the HDO(2{0,2}-1{1,1}) line have been observed, as well as the 1{0}-0{1} lines from NH{3} and its rare isotopologue 15NH{3}. We suggest assignments for some unidentified features, notably the new interstellar molecules ND and SH-. Severe blends have been detected in the

  7. Comparison of GOME tropospheric NO2 columns with NO2 profiles deduced from ground-based in situ measurements

    Directory of Open Access Journals (Sweden)

    D. Schaub

    2006-01-01

    Full Text Available Nitrogen dioxide (NO2 vertical tropospheric column densities (VTCs retrieved from the Global Ozone Monitoring Experiment (GOME are compared to coincident ground-based tropospheric NO2 columns. The ground-based columns are deduced from in situ measurements at different altitudes in the Alps for 1997 to June 2003, yielding a unique long-term comparison of GOME NO2 VTC data retrieved by a collaboration of KNMI (Royal Netherlands Meteorological Institute and BIRA/IASB (Belgian Institute for Space Aeronomy with independently derived tropospheric NO2 profiles. A first comparison relates the GOME retrieved tropospheric columns to the tropospheric columns obtained by integrating the ground-based NO2 measurements. For a second comparison, the tropospheric profiles constructed from the ground-based measurements are first multiplied with the averaging kernel (AK of the GOME retrieval. The second approach makes the comparison independent from the a priori NO2 profile used in the GOME retrieval. This allows splitting the total difference between the column data sets into two contributions: one that is due to differences between the a priori and the ground-based NO2 profile shapes, and another that can be attributed to uncertainties in both the remaining retrieval parameters (such as, e.g., surface albedo or aerosol concentration and the ground-based in situ NO2 profiles. For anticyclonic clear sky conditions the comparison indicates a good agreement between the columns (n=157, R=0.70/0.74 for the first/second comparison approach, respectively. The mean relative difference (with respect to the ground-based columns is −7% with a standard deviation of 40% and GOME on average slightly underestimating the ground-based columns. Both data sets show a similar seasonal behaviour with a distinct maximum of spring NO2 VTCs. Further analysis indicates small GOME columns being systematically smaller than the ground-based ones. The influence of different shapes in the a

  8. ESA takes part in Earth observation and space science experiments on board the Space Shuttle

    Science.gov (United States)

    1993-03-01

    interesting phenomena show up. The third European instrument, called MAS (Millimeter Wave Atmospheric Sounder) will be measuring the absorption spectra of water vapour and trace gases in the upper atmosphere. The measurement programme includes most notably ozone and chlorine monoxide, which plays an important role in the ozone cycle. MAS was developed under the responsibility of Dr. Gerd Hartmann of the Max-Planck- Institute fuer Aeronomy, Lindau, Germany. The complex space-to-ground communications links and the tools to control the instruments from the laboratories in Europe have been designed to be as flexible and user-friendly as possible. The series of Atlas missions is enabling ESA to gain valuable experience for the future utilisation of its Columbus Attached Laboratory; its science results are at the same time a contribution to today's advances in space science and environmental research, complementing a number of dedicated ESA satellites currently under development, such as SOHO, ERS-2 and ENVISAT-1. Note to Editors : At the invitation of the Belgian Minister for Science Policy a press conference will be held on 22 March 1993 at 16.00 hours at the Belgian Royal Meteorological Institute in Brussels (IRMB). The press conference will be followed by the inauguration of the Space Remote Operations Centre, from where the telescience operations for the ATLAS-2 mission will be carried out. Apart from the Minister, those participating will include: Dirk Frimout, Belgian astronaut and ESA staff member Dominique Crommelynck, IRMB, Principal Investigator for SOLCON Gerard Thuillier, CNRS France, Principal Investigator for SOLSPEC Further information can be obtained from the Belgian Science Policy Office, Mrs. M.C. Limbourg or Mr. J. Bernard : Tel : +32.2.238.34.11 - Fax : +32.2.230.59.12

  9. The CompreHensive collaborativE Framework (CHEF)

    Science.gov (United States)

    Knoop, P. A.; Hardin, J.; Killeen, T.; Middleton, D.

    2002-12-01

    Data integration, publication, and archiving have become important considerations in most fields of science as experiments and models increase in complexity, and the collaborations necessary to conduct the research grow broader. The development of well thought out strategies and standards for such data handling, however, only goes part way in supporting the scientific process. A primary driving force for such efforts is the need of scientists to access and work with data in a timely, reasonable, and often collaborative fashion. Internet-based collaborative environments are one way to help complete this picture, linking scientists to the data they seek and to one another (e.g., Towards a Robust, Agile, and Comprehensive Information Infrastructure for the Geosciences: A Strategic Plan For High Performance Simulation, NCAR, 2000, http://www.ncar.ucar.edu/Director/plan.pdf). The CompreHensive collaborativE Framework (CHEF, http://chefproject.org) is a generic, extensible, web-based, open-source environment for collaboration. CHEF's goal is to provide the basic building blocks from which a community can assemble a collaborative environment that fits their needs. The design of CHEF has been influenced by our experience developing the Space Physics and Aeronomy Research Collaboratory (SPARC, http://www.si.umich.edu/SPARC), which provides integrated access to a wide variety of heterogeneous data sources, including community-standardized data bases. The design has also been heavily influenced by our involvement with an effort to extract and codify the broad underlying technical and social elements that lead to successful collaboratories (http://www.scienceofcollaboratories.org). A collaborative environment is in itself also not the complete answer to data handling, rather, it provides a facilitating environment in which community efforts to integrate, publish, archive, and share data using standard formats and practices can be taken advantage of by the end-users, the

  10. 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)

  11. Formaldehyde and Glyoxal: New Products in the SCIAMACHY Operational Processor

    Science.gov (United States)

    Hrechanyy, Serhiy; de Smedt, Isabelle; Kretschel, Klaus; Lichtenberg, Günter; Meringer, Markus; Wittrock, Folkard

    In sommer of 2010 version 6 of the SCIAMACHY operational processor is planned to be deliv-ered to ESA. The SCIAMACHY Quality Working Group recommended an implementation of the formalde-hyde (HCHO) and glyoxal (CHOCHO) vertical columns into version 6 of the off-line processor. They are formed during the oxidation of volatile organic compounds (VOCs) emitted by plants, anthropogenic activities, and biomass burning. Due to a rather short lifetime of formaldehyde and glyoxal, their distribution maps, obtained by the SCIAMACHY, represent the emission fields of their precursors, VOCs. The descriptions of reference algorithm as well as all the cross-sections for formaldehyde and glyoxal retrievals were delivered to DLR by the Belgian Institute for Space Aeronomy (BIRA) (I. De Smedt, 2008) and by the IUP (F. Wittrock, 2006), respectively. Both retrievals are based on the DOAS technique. For the formaldehyde retrieval the spectral region of 328.5-346 nm was recommended. The absorption cross-sections of HCHO, O3, NO2, BrO, OClO, a Ring spectrum and a polynomial of the fifth order are included into the fitting procedure. Before conversion to the vertical columns, the slant columns have to be normal-ized by subtracting the slant columns measured over Pacific ocean, where the only source of formaldehyde is methane oxidation. After the conversion to the vertical columns, part of HCHO removed during the previous procedure has to be re-added to the final vertical column by adding of the mean vertical column calculated by the tropospheric chemistry model IMAGES (J.-F. Müller, 1995). This normalization is necessary to compensate for the offset introduced by the solar reference measurements and interferences by other absorbers. For the determination of glyoxal columns, the spectral region 435-457 nm was selected. In this case, the absorption cross-sections of CHOCHO, O3, NO2, H2O, O4, a Ring spectrum and a cubic polynomial are included in the fitting procedure. The normalization of

  12. 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

  13. 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

  14. 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

  15. 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

  16. 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

  17. 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

  18. 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

  19. Shoemaker-Levy 9/JUPITER Collision Update

    Science.gov (United States)

    1994-05-01

    Information Service (Tel.: +4989-32006276; Fax: +4989-3202362), to obtain a personal invitation. ESO is preparing special arrangements for the Chilean media; they will soon be announced directly to the involved. PHOTO CAPTION ESO PR PHOTO 10/94-1: PORTRAIT OF A DOOMED COMET These two photos from the ESO La Silla observatory show the individual nuclei of comet Shoemaker-Levy 9, now headed for collision with Jupiter on 16 - 22 July 1994. The wide-field photo (below, left) was obtained by Klaus Jockers and Galina Chernova (Max-Planck-Institute fur Aeronomie, Katlenburg, Lindau, Germany) on May 1, 1994. For this 5 min exposure in red light they used a CCD camera at the MPIfAe/Hoher List focal reducer at the ESO 1-metre telescope. The entire nuclear train (the "string of pearls") is very well seen, together with the sunlight-reflecting dust from the nuclei, all on one side. On this date, the comet was 654 million km from the Earth and the angular extension of the train was about 5.3 arcmin, corresponding to a projected length of just over 1 million km. A 15 min CCD image was obtained for astrometric purposes on May 11, 1994, by Jean-Francois Claeskens at the Danish 1.5 m telescope at La Silla; it is here reproduced in close-up to show well the individual nuclei, in particular the fainter ones. The bright object to the upper right is a 10th mag star. Note that the stars in the field are somewhat trailed, since the telescope was set to follow the motion of the comet. The first nucleus to hit Jupiter will be "A", here seen 42 mm from the left edge and 33 mm below the upper edge of the large picture. The last is "W", 43 mm above the lower edge and 9 mm from the right edge. The comet was 657 million km from the Earth and the train was somewhat longer, 5.8 arcmin, i.e. the projected length was now 1.1 million km. Technical information: Wide-Field: pixel size 1.5 arcsec; scale on photo: 5.1 arcsec/mm; field size: 12.2 x 6.6 arcmin; 5 min exposure; gunn-r filtre. Close-Up: pixel size 0