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Sample records for 3-13 km altitudes

  1. Pulsed Airborne Lidar Measurements of Atmospheric CO2 Column Absorption and Line Shapes from 3-13 km Altitudes

    NASA Technical Reports Server (NTRS)

    Abshire, J. B.; Riris, H.; Allan, G. R.; Weaver, C.; Hasselbrack, W.; Sun, X.

    2009-01-01

    altitudes were evident and comparison with in-situ measurements showed agreements to 6 ppm. This spring we improved the aircraft's nadir window. During July and August 2009 we made 9 additional 2 hour long flights and measured the atmospheric C02 absorption and line shapes using the 1572.33 nm C02 line. Measurements were made at stepped altitudes from 3-13 km over a variety of surface types in Nebraska, Illinois, the SGP ARM site, and near and over the Chesapeake Bay in North Carolina and Virginia. Strong laser signals and clear line shapes were observed at all altitudes, and some measurements were made through thin clouds. The flights over the ARM site were underflown with in-situ measurements made from the DOE Cessna. The Oklahoma and east coast t1ights were coordinated with a LaRC/ITT C02 lidar on the LaRC UC-12 aircraft, a LaRC insitu C02 sensor, and the Oklahoma flights also included a JPL C02 lidar on a Twin Otter aircraft. Ed Browell and Gary Spiers led the LaRC and JPL teams. More details of the t1ights, measurements and analysis will be described in the presentation.

  2. Pulsed Airborne Lidar measurements of Atmospheric CO2 Column Absorption and Line Shapes from 3-13 km altitudes

    NASA Astrophysics Data System (ADS)

    Abshire, J. B.; Riris, H.; Allan, G. R.; Weaver, C. J.; Hasselbrack, W. E.; Sun, X.

    2009-12-01

    increasing CO2 line absorptions with altitudes were evident and comparison with in-situ measurements showed agreements to 6 ppm. This spring we improved the aircraft’s nadir window. During July and August 2009 we made 9 additional 2 hour long flights and measured the atmospheric CO2 absorption and line shapes using the 1572.33 nm CO2 line. Measurements were made at stepped altitudes from 3-13 km over a variety of surface types in Nebraska, Illinois, the SGP ARM site, and near and over the Chesapeake Bay in North Carolina and Virginia. Strong laser signals and clear line shapes were observed at all altitudes, and some measurements were made through thin clouds. The flights over the ARM site were underflown with in-situ measurements made from the DOE Cessna. The Oklahoma and east coast flights were coordinated with a LaRC/ITT CO2 lidar on the LaRC UC-12 aircraft, a LaRC in-situ CO2 sensor, and the Oklahoma flights also included a JPL CO2 lidar on a Twin Otter aircraft. Ed Browell and Gary Spiers led the LaRC and JPL teams. More details of the flights, measurements and their analysis will be described in the presentation.

  3. Pulsed Airborne Lidar Measurements of Atmospheric CO2 Column Absorption and Line Shapes from 3-13 km Altitudes

    NASA Technical Reports Server (NTRS)

    Abshire, James; Riris, Haris; Allan, Graham; Weaver, Clark; Mao, Jianping; Sun, Xiaoli; Hasselbrack, William

    2010-01-01

    US Department of Energy's (DOE) SGP ARM site at altitudes from 3-8 km. These flights were coordinated with DOE investigators who flew an in-situ CO2 sensor on a Cessna aircraft under the path. The increasing CO2 line absorptions with altitudes were evident and comparison with in-situ measurements showed agreements to 6 ppm. In spring 2009 we improved the aircraft's nadir window and during July and August we made 9 additional 2 hour long flights and measured the atmospheric CO2 absorption and line shapes using the 1572.33 nm CO2 line. Measurements were made at stepped altitudes from 3-13 km over a variety of surface types in Nebraska, Illinois, the SGP ARM site, and near and over the Chesapeake Bay in North Carolina and eastern Virginia. Strong laser signals and clear CO2 line shapes were observed at all altitudes, and some measurements were made through thin clouds. The flights over the ARM site were underflown with in-situ measurements made from the DOE Cessna. Analysis shows that the average signal levels follow predicted values, the altimetry measurements had an uncertainty of about 4 m, and that the average optical line depths follow the number density calculated from in-situ sensor readings. The Oklahoma and east coast flights were coordinated with a LaRC/ITT CO2 lidar on the LaRC UC-12 aircraft, a LaRC in-situ CO2 sensor, and the Oklahoma flights also included a JPL CO2 lidar on a Twin Otter aircraft. More details of the flights, measurements, analysis and scaling to space will be described in the presentation.

  4. Analysis of Pulsed Airborne Lidar Measurements of Atmospheric CO2 Column Absorption from 3-13 km Altitudes

    NASA Technical Reports Server (NTRS)

    Abshire, James B.; Weaver, Clark J.; Riris, Haris; Mao, Jianping; Sun, Xiaoli; Allan, Graham R.; Hasselbrack, William; Browell, Edward V.

    2011-01-01

    We have developed a pulsed lidar technique for measuring the tropospheric CO2 concentrations as a candidate for NASA's ASCENDS space mission [1]. It uses two pulsed laser transmitters allowing simultaneous measurement of a CO2 absorption line in the 1575 nm band, O2 extinction in the Oxygen A-band, surface height and backscatter profile. The lasers are precisely stepped in wavelength across the CO2 line and an O2 line region during the measurement. The direct detection receiver measures the energies of the laser echoes from the surface along with the range profile of scattering in the path. The column densities for the CO2 and O2 gases are estimated from the ratio of the on- and off-line signals via the integrated path differential absorption (IPDA) technique. The time of flight of the laser pulses is used to estimate the height of the scattering surface and to reject laser photons scattered in the atmosphere. We developed an airborne lidar to demonstrate an early version of the CO2 measurement from the NASA Glenn Lear-25 aircraft. The airborne lidar stepped the pulsed laser's wavelength across the selected CO2 line with 20 wavelength steps per scan. The line scan rate is 450 Hz, the laser pulse widths are 1 usec, and laser pulse energy is 24 uJ. The time resolved laser backscatter is collected by a 20 cm telescope, detected by a NIR photomultiplier and is recorded on every other reading by a photon counting system [2]. During August 2009 we made a series of 2.5 hour long flights and measured the atmospheric CO2 absorption and line shapes using the 1572.33 nm CO2 line. Measurements were made at stepped altitudes from 3-13 km over locations in the US, including the SGP ARM site in Oklahoma, central Illinois, north-eastern North Carolina, and over the Chesapeake Bay and the eastern shore of Virginia. Although the received signal energies were weaker than expected for ASCENDS, clear CO2 line shapes were observed at all altitudes, and some measurements were made

  5. Neutral Wind Observations below 200 km altitudes

    NASA Astrophysics Data System (ADS)

    Watanabe, S.; Abe, T.; Habu, H.; Kakinami, Y.; Larsen, M. F.; Pfaff, R. F., Jr.; Yamamoto, M.

    2015-12-01

    Neutral Wind Observations below 200 km altitudesS. Watanabe1, T. Abe2, H. Habu2, Y. Kakinami3, M. Larsen4, R. Pfaff5, M. Yamamoto6, M-Y. Yamamoto31Hokkaido University/Hokkaido Information University, 2JAXA/ISAS, 3Kochi University of Technology, 4Clemson University, 5NASA/Goddard Space Flight Center, 6Kyoto University, Neutral wind in the thermosphere is one of the key parameters to understand the ionosphere-thermosphere coupling process. JAXA/ISAS successfully launched sounding rockets from Uchinoura Space Center (USC) on September 2, 2007, January 12, 2012, and July 20, 2013, and NASA launched sounding rockets from Kwajalein on May 7, 2013 and from Wallops on July 4, 2013. The rockets installed Lithium and/or TMA canisters as well as instruments for plasma and electric and magnetic fields. The atomic Lithium gases were released at altitudes between 150 km and 300 km in the evening on September 2, 2007, at altitude of ~100 km in the morning on January 12, 2012, at altitude of ~120km in the midnight on July 20, 2013, at altitude between 150 km and 300 km in the evening on May 7, 2013 and at altitude of ~150 km in the noon on July 4, 2013. The Lithium atoms were scattering sunlight by resonance scattering with wavelength of 670nm. However, the Lithium atoms scattered moon light on July 20, 2013. The moon light scattering is the first time to use for thermospheric wind measurement in the midnight. The Lithium clouds/trails and TMA trails showed clearly the neutral wind shears and atmospheric waves at ~150 km altitude in the lower thermosphere for all local time.

  6. Simulation of CO2 release at 800 km altitude

    NASA Astrophysics Data System (ADS)

    Setayesh, A.

    1993-08-01

    The SOCRATES contamination-interaction code has been used to simulate the reactions of 0 + CO2 yields CO2(v) + O, O + CO2 - CO(v) + O2, and CO2 + H - CO + OH(v) at an altitude of 800 km in both ram and wake directions of the spacecraft. These simulations show that the radiation from these reactions can be measurable for the parameters which have been used in these calculations. The investigation carries out the simulations as much as 30 km from the spacecraft. The radiative intensity of CO(v) and OH(v) show the highest and lowest, respectively.

  7. Transport System for Delivery Tourists At Altitude 140 km

    NASA Technical Reports Server (NTRS)

    Bolonkin, Alexander

    2002-01-01

    The author offers a new method and installation for flight in space. This method uses the centrifugal force of a rotating circular cable that provides a means for the launch of a payload into outer space, to keep the fixed space stations at high altitudes (up to 200 km). The method may also be useful for landing to space bodies, for launching of the space ships (crafts), and for moving and accelerating other artificial apparatuses. The offered installation may be used as a propulsion system for space ships and/or probes. This system uses the material of any space body (i.e. stones) for acceleration and change of the space vehicle trajectory. The suggested system may be also used as a high capacity energy accumulator.

  8. Dosimetry of secondary cosmic radiation up to an altitude of 30 km.

    PubMed

    Wissmann, F; Burda, O; Khurana, S; Klages, T; Langner, F

    2014-10-01

    Dosimetric measurements in the field of secondary cosmic radiation were extensively made during the last years. Since the majority of these measurements were performed on-board passenger aircraft at altitudes between 10 and 12 km, measurements at higher altitudes are desirable for the verification of the legal dose assessment procedures for aircrew. A simple solution is to use a high-altitude balloon that reaches altitudes as high as 30 km. In this work, it is shown that the dose rate profile up to 30 km can be measured with acceptable uncertainties using a Si-detector.

  9. Cape Canaveral, Florida range reference atmosphere 0-70 km altitude

    NASA Technical Reports Server (NTRS)

    Tingle, A. (Editor)

    1983-01-01

    The RRA contains tabulations for monthly and annual means, standard deviations, skewness coefficients for wind speed, pressure temperature, density, water vapor pressure, virtual temperature, dew-point temperature, and the means and standard deviations for the zonal and meridional wind components and the linear (product moment) correlation coefficient between the wind components. These statistical parameters are tabulated at the station elevation and at 1 km intervals from sea level to 30 km and at 2 km intervals from 30 to 90 km altitude. The wind statistics are given at approximately 10 m above the station elevations and at altitudes with respect to mean sea level thereafter. For those range sites without rocketsonde measurements, the RRAs terminate at 30 km altitude or they are extended, if required, when rocketsonde data from a nearby launch site are available. There are four sets of tables for each of the 12 monthly reference periods and the annual reference period.

  10. Recent Pulsed Airborne Lidar measurements of Atmospheric CO2 Column Absorption to 13 km altitudes

    NASA Astrophysics Data System (ADS)

    Abshire, J. B.; Riris, H.; Allan, G. R.; Weaver, C. J.; Mao, J.; Hasselbrack, W.; Sun, X.; Rodriguez, M. R.

    2010-12-01

    We have developed a lidar technique for measuring atmospheric CO2 concentrations as a candidate for NASA’s ASCENDS mission. It uses pulsed laser transmitters to simultaneously measure a CO2 absorption line in the 1570 nm band, O2 extinction in the Oxygen A-band and surface height and backscatter. The lidar measures the energy and time of flight of the laser echoes reflected from the atmosphere and surface. The lasers step in wavelength across the CO2 line and an O2 line pair during the measurement. The receiver uses a telescope and photon counting detectors, and measures the time resolved backscatter of the laser echoes. Signal processing is used to isolate the laser echo signals from the surface, estimate their range, and reject laser photons scattered in the atmosphere. The gas extinction and column densities for the CO2 and O2 gases are estimated via the IPDA technique. We developed a lidar to demonstrate the CO2 measurement from aricraft. The lidar steps the pulsed laser’s wavelength across a selected CO2 line with 20 or 30 steps per scan. The line scan rate is 450 Hz and laser pulse widths are 1 usec. The time resolved laser backscatter is collected by a 20 cm telescope, detected by a photomultiplier and is recorded by a photon counting system. During July and August 2009 we made 5 two hour long flights while installed on the NASA Glenn Lear-25 aircraft. We measured the atmospheric CO2 absorption and line shapes using the 1572.33 nm CO2 line. Measurements were made at stepped altitudes from 3-13 km over a variety of surfaces in Nebraska, Illinois, the SGP ARM site, and near and over the Chesapeake Bay. Strong laser signals and clear line shapes were observed at all altitudes, and some measurements were made through thin clouds. The Oklahoma and east coast flights were coordinated with the NASA LaRC/ITT CO2 lidar on their UC-12 aircraft, a LaRC in-situ CO2 sensor, and the Oklahoma flights also included a JPL CO2 lidar on a Twin Otter aircraft. Ed Browell

  11. Extending the Purple Crow Lidar Temperature Climatology Above 100 km Altitude Using an Inversion Approach

    NASA Astrophysics Data System (ADS)

    Jalali, A.; Sica, R. J.; Argall, S.; McCullough, E. M.

    2013-12-01

    Temperature retrievals from Rayleigh-scattering lidar measurements have been performed using the algorithm given by Chanin and Hauchecorne (1980; henceforth CH) for the last 3 decades. Recently Khanna et al. have presented an inversion approach to retrieve atmospheric temperature profiles. This method uses a nonlinear inversion method with a Monte Carlo technique to determine the statistical uncertainties for the retrieved nightly average temperature profiles. Using this approach, Purple Crow Lidar temperature profiles can now be extended 10 km higher in altitude compared to those calculated with the CH method, with reduced systematic uncertainty. Argall and Sica (2007) used the CH method to produce a climatology of the Purple Crow Lidar measurements from 1994 to 2004 which was compared with the CIRA-86 model. The CH method integrates temperatures downward, and requires the assumption of a 'seed' pressure at the highest altitude, taken from a model. Geophysical variation here, in the lower thermosphere, is sufficiently large to cause temperature retrievals to be unreliable for the top 10 or more km; uncertainties due to this pressure assumption cause the top two scale heights of temperatures from each profile to be discarded until the retrieval is no longer sensitive to the seed pressure. Khanna et al. (2012) use an inversion approach which allows the corrected lidar photocount profile to be integrated upward, as opposed to downward as required by the CH method. Khanna et al. (2012) showed that seeding the retrieval at the lowest instead of top height allows a much smaller uncertainty in the contribution of the seed pressure to the temperature compared to integrating from the top of the profile. Two other benefits to seeding the retrieval at the lower altitudes (around 30 km) include reduced geophysical variability, and the availability of routine pressure measurements from radiosondes. This presentation will show an extension of the Khanna et al. (2012) comparison

  12. GPS-aided gravimetry at 30 km altitude from a balloon-borne platform

    NASA Technical Reports Server (NTRS)

    Lazarewicz, Andrew R.; Evans, Alan G.

    1989-01-01

    A balloon-borne experiment, flown at 30 km altitude over New Mexico, was used to test dynamic differential Global Positioning System (GPS) tracking in support of gravimetry at high-altitudes. The experiment package contained a gravimeter (Vibrating String Accelerometer), a full complement of inertial instruments, a TI-4100 GPS receiver and a radar transponder. The flight was supported by two GPS receivers on the ground near the flight path. From the 8 hour flight, about a forty minute period was selected for analysis. Differential GPS phase measurements were used to estimate changes in position over the sample time interval, or average velocity. In addition to average velocity, differential positions and numerical averages of acceleration were obtained in three components. Gravitational acceleration was estimated by correcting for accelerations due to translational motion, ignoring all rotational effects.

  13. Low latitude thermospheric meridional winds between 250 and 450 km altitude - AE-E satellite data

    NASA Technical Reports Server (NTRS)

    Herrero, F. A.; Mayr, H. G.; Spencer, N. W.

    1988-01-01

    In situ measurements from the Atmosphere Explorer-E satellite are used to obtain the daily variations of the meridional wind at + or - 18 deg latitude for summer and winter between 1977 and 1979. Data are presented for altitudes around 270, 350, and 440 km. Two features showing significant seasonal variation are found: a late afternoon maximum of the poleward wind occurring in winter at 1800 LT and a nighttime maximum in the equatorward wind with the summer equatorward wind abating earlier and more rapidly than the winter wind. The characteristics of these seasonal variations are discussed in detail.

  14. The O+ Density Trough at 5000 km Altitude in the Polar Cap

    NASA Technical Reports Server (NTRS)

    Zeng, W.; Horowitz, J. L.; Cravens, P. D.; Rich, F. J.; Moore, T. E.

    2003-01-01

    At altitudes near 5000 km over the Southern polar cap region of the terrestrial magnetospherehonosphere, the Thermal Ion Dynamics Experiment (TIDE) onboard the Polar satellite has observed O+ ion density trough regions, in which the O+ densities were at least one order of magnitude lower than the surrounding O+ densities. In the O+ demify trough regions, the estimated O+ densities were generally lower than 0.01 per cc. The boundaries between normal density level regions and the trough density regions were usually abrupt transitions. From December 1, 1997 to November 30, 1998, polar cap O+ troughs in Polar/TIDE observations occurred at a frequency of about 48%. Statistical examination of the Polar perigee observations from December 1 , 1997 to November 30, 1998 shows that the Polar perigee passes evenly covered the southern polar cap region, while the O+ density trough was always located on the nightside portion of the polar cap magnetospherehonosphere, and that invariant latitude spans of such troughs could be as large as 230 in extent. The trough occurrence displayed strong seasonal dependence; in the winter season (e.g. for July in the southern hemisphere) the O+ ion density trough occurrence frequency ranged up to 92%, while in the summer season (e.g. for January in the southern hemisphere) it decreased to as infrequent as 15%. The O+ ion density trough occurrence appeared relatively independent of the geomagnetic Kp index, and IMF Bz, By conditions. However, as suggested by the seasonal dependence, the O+ ion density trough occurrence was strongly related to the solar zenith angle (SZA). In the SZA range 500 to 1250, the trough occurrence increased monotonically with SZA. Also, case-by-case examinations of near-simultaneous O+ densities and vertical velocities observed by the DMSP satellite group orbiting at 840 km altitude indicate that the O+ density troughs observed at 5000 km altitude exhibit moderate correlation or anti-correlation with topside ionosphere

  15. Neutral hydrogen flux measured at 100- to 200-km altitude in an electron aurora

    NASA Technical Reports Server (NTRS)

    Iglesias, G. E.; Anderson, H. R.

    1975-01-01

    Neutral hydrogen fluxes were measured at altitudes of 120-200 km by a rocket payload that also measured electron and proton fluxes and vector magnetic fields. An intense electron arc was crossed, while an upper limit to the flux of 0.5- to 20-keV protons was 1,000,000 per sq cm s sr keV. A neutral flux of 50,000,000 per sq cm s sr was observed, assuming hydrogen with greater than 1-keV energy, with greater north-south extent than the electron flux. Its pitch angle distribution was peaked toward 90 deg, tending toward isotropy in the center. This is fitted to a model describing spreading of an initial proton arc above 500 km.

  16. The O(+) Density Trough at 5000 km Altitude in the Polar Cap

    NASA Technical Reports Server (NTRS)

    Zeng, W.; Horwitz, J. L.; Craven, P. D.; Rich, F. J.; Moore, T. E.

    2004-01-01

    At altitudes near 5000 km over the southern polar cap region of the terrestrial magnetosphere/ionosphere, the Thermal Ion Dynamics Experiment (TIDE) on board the Polar satellite has observed O(+) ion density trough regions, in which the densities were at least one order of magnitude lower than the surrounding O(+) densities. In the 0" density trough regions, the estimated O+ densities were generally lower than 0.01 per cc. The boundaries between normal density level regions and the trough density regions were usually abrupt transitions. From 1 December 1997 to 30 November 1998, polar cap O(+) troughs in Polar/TIDE observations occurred at a frequency of about 48%. Statistical examination of the Polar perigee observations from 1 December 1997 to 30 November 1998 shows that the Polar perigee passes evenly covered the southern polar cap region, while the O(+) density trough was always located on the nightside portion of the polar cap magnetosphere/ionosphere, and that invariant latitude spans of such troughs could be as large as 23 deg. in extent. The trough occurrence displayed a strong seasonal dependence; in the winter season (e.g., for July in the Southern Hemisphere) the O(+) ion density trough occurrence frequency ranged up to 92%, while in the summer season (e.g., for January in the Southern Hemisphere) it decreased to as low as 15%. Our statistical results show that the trough occurrence was generally anticorrelated with solar wind dynamic pressure in the solar wind dynamic pressure range 0.8 - 2.6 nanopascal. The O(+) ion density trough occurrence appeared relatively independent of the geomagnetic Kp index, IMF Bz, and By conditions. However, as suggested by the seasonal dependence, the O(+) ion density trough occurrence was strongly related to the solar zenith angle (SZA). In the SZA range 50 deg. to 125 deg., the trough occurrence increased monotonically with SZA. In addition, we sought to determine consistent density and velocity signatures at lower

  17. Asymmetric Penetration of Shocked Solar Wind Down to 400-km Altitudes at Mars

    NASA Astrophysics Data System (ADS)

    Matsunaga, K.; Seki, K.; Hara, T.; Brain, D. A.

    2014-12-01

    The solar wind interaction with a planetary atmosphere produces the magnetic pile-up region near the planet. The Martian magnetic pile-up region prevents direct penetration of shocked solar wind (magnetosheath) plasma and the penetration boundary is typically located at altitudes above 800 km. Spacecraft measurements have shown, however, that magnetosheath plasma occasionally penetrates into low altitudes below 400 km. Here we used Mars Global Surveyor magnetic field and electron observations during the period from April 1999 to November 2006 to investigate the magnetosheath penetration events. We identified 240 events and found that both solar wind dynamic pressure (Psw) and the orientation of the interplanetary magnetic field (IMF) control the occurrence of the events. The magnetosheath penetration events during the low Psw periods tend to be distributed in low latitudes of the northern hemisphere where the crustal magnetic field is weak, while the event locations widely distributed in terms of the latitude under high Psw conditions. During the low Psw periods, a remarkable feature is that the observational probability is approximately 7 times larger during periods of the "away" IMF sector than during the "toward" sector. These results thus indicate that the magnetosheath penetrations into Martian upper atmosphere more often occur in the upward electric field hemisphere than in the downward electric field hemisphere. Large-amplitude undulation excited by the Kelvin-Helmholtz instability in the upward electric field hemisphere previously suggested from global hybrid simulation can be one of candidate processes to cause the asymmetric penetration during low Psw periods.

  18. Characterization of cosmic rays and direction dependence in the Polar Region up to 88 km altitude

    NASA Astrophysics Data System (ADS)

    Zábori, Balázs; Hirn, Attila; Deme, Sándor; Apáthy, István; Pázmándi, Tamás

    2016-02-01

    Aims: The sounding rocket experiment REM-RED was developed to operate on board the REXUS-17 rocket in order to measure the intensity of cosmic rays. The experiment was launched from the ESRANGE Space Center (68 °N, 21 °E) on the 17th of March 2015 at the beginning of the most intense geomagnetic storm within the preceding 10 years. The experiment provided the opportunity to measure the intensity of cosmic rays in the Polar Region up to an altitude of 88 km above sea level. Methods: The experiment employed Geiger-Müller (GM) counters oriented with their axes perpendicular to each other in order to measure the cosmic ray intensity during the flight of the rocket. This measurement setup allowed performing direction-sensitive measurements as well. During the ascent phase the rocket was spinning and hence stabilized along its longitudinal axis looking close to the zenith direction. This phase of the flight was used for studying the direction dependence of the charged particle component of the cosmic rays. Results: In comparison with earlier, similar rocket experiments performed with GM tubes at lower geomagnetic latitudes, significantly higher cosmic radiation flux was measured above 50 km. A non-isotropic behavior was found below 50 km and described in detail for the first time in the Polar Region. This behavior is in good agreement with the results of the TECHDOSE experiment that used the same type of GM tubes on board the BEXUS-14 stratospheric balloon.

  19. Evolution of Pinatubo aerosol near 19 km altitude over western North America

    NASA Technical Reports Server (NTRS)

    Goodman, Jindra; Snetsinger, K. G.; Pueschel, R. F.; Ferry, G. V.; Verma, S.

    1994-01-01

    Stratospheric aerosols, collected near 19 km altitude on wire impactors over western North America from August 20, 1991 to May 11, 1993, show strong influence of the June 1991 Mt. Pinatubo eruption. Lognormal size distributions are bimodal; each of the mode radii increases and reaches maximum value at about 15 months after eruption. The second (large particle) mode becomes well developed then, and about 40% of the droplets are larger than 0.4 micron radius. The eruption of Mt. Spurr (Alaska) may also have contributed to this. Sulfate mass loading decays exponentially (e-folding 216 days), similar to El Chichon. Silicates are present in samples only immediately after eruption. Two years after eruption, sulfate mass loading is about 0.4 micrograms/cu m, about an order of magnitude higher than background pre-volcanic values. Aerosol size distributions are still bimodal with a very well-defined large droplet mode.

  20. POLAR/TIDE Survey of Thermal O+ Characteristics near 5000km Altitude over the Polar Cap

    NASA Technical Reports Server (NTRS)

    Stevenson, B. A.; Horwitz, J. L.; Su, Y. J.; Elliott, Heather A.; Comfort, Richard H.; Moore, Thomas E.; Giles, Barbara A.; Craven, Paul D.; Chandler, Michael O.; Pollock, Craig J.

    1998-01-01

    We analyze measurements of thermal 0+ parameters from the Thermal Ion Dynamics Experiment (TIDE) on POLAR for April - May, 1996 obtained near 5000 km altitude within the polar cap ionosphere - magnetosphere interface region. Certain aspects of O+ parameters in this region were explored by Su et. al. [1998]. In this report, we hope to extend our understanding of the O+ behavior by examining relationships of densities, parallel velocities, and temperatures to the convection velocities, IMF By and Bz components. Preliminary results with the convection velocities are currently being analyzed. In doing so, we are guided in part by the Cleft Ion Fountain paradigm and model developed by Horwitz and Lockwood [1985] which involves downward O+ flows in the polar magnetosphere.

  1. Ion density and temperature variations at altitude of 500 km during moderate seismic activity

    NASA Astrophysics Data System (ADS)

    Bardhan, Ananna; Khurana, M. S.; Bahal, B. M.; Aggarwal, Malini; Sharma, D. K.

    2017-02-01

    Ionospheric ions (O+ and H+) and temperature (Ti) as precursory parameters to seismic activity have been analysed from year 1995 till 1998, using SROSS-C2 (average altitude range of ∼500 km) satellite measurements for moderate magnitude earthquakes. The details of seismic events during this period are downloaded from United State Geological Survey (USGS) and National Earthquake Information Centre (NEIC) website. 13 seismic events of moderate magnitude (M = 4-5.5) from 1995 to 1998, using SROSS-C2 satellite measurements have been analysed. During seismic affected period, considerable decrease in the density of heavier ion - O+ and increase in the ion temperature (Ti) is observed during all the selected events. Lighter ion - H+ doesn't show any significant change. Electric field and electromagnetic emissions generated due to seismogenic activity could be the plausible initializing agents responsible for change in ion concentration and temperature values during these events.

  2. Detection of EUV/Soft X-ray bremsstrahlung emission at terrestrial altitudes above 750 km

    NASA Astrophysics Data System (ADS)

    Katsiyannis, A.; Dominique, M.; De Keyser, J.; Berghmans, D.; Michel, K.; Dammasch, I. E.; Borremans, K.; De Donder, E.; Ben Moussa, A.

    2015-12-01

    LYRA is a fast radiometer on-board the PROBA-2 mission designed to observe the solar activity from UV to Soft X-rays and consists of three redundant units of four different optical bandpasses each. Since the start of operation in 2010, LYRA regularly observes disturbances with a characteristic signature that have no direct solar origin. Instead the frequency of occurrence correlates with the ApA_p index of geomagnetic activity on Earth's surface and the location of these detections coincides with the McIlwain L ≈ 3 zon. By comparing the wavelength sensitivity of the main PROBA-2 instruments, the wavelength range of the detected photons can be narrowed down to the range of 0.07-1 KeV (1-17 nm) and the altitudes of their source to those above PROBA-2's orbit (~750 km). A discussion on the magnetospheric origins of this emission is included.

  3. Aerobic capacity and running performance across a 1.6 km altitude difference in two sciurid rodents.

    PubMed

    Chappell, Mark A; Dlugosz, Elizabeth M

    2009-03-01

    Hypoxia at high altitudes is often assumed to constrain exercise capacity, but there have been few high- versus low-altitude comparisons of species native to a wide range of altitudes. Such studies are ecologically realistic, as wild-caught animals tested at their native altitude are presumably maximally acclimated (via phenotypic plasticity) or adapted (by evolutionary change) to that altitude. We compared aerobic performance, measured as maximum oxygen consumption in forced exercise (V(O(2),max)), and voluntary wheel-running in two species of sciurid rodents captured and tested at field sites that differed in altitude by 1.6 km (2165 m versus 3800 m). We found reduced V(O(2),max) at 3800 m in least chipmunks (Tamias minimus) but no significant effect of altitude on V(O(2),max) in golden-mantled ground squirrels (Spermophilus lateralis). Individuals of both species averaged several km day(-1) in wheels. Most behavioral indices of voluntary running (including mean and maximum speeds, time spent running, daily running distance, and the number and duration of running bouts) were unaffected by altitude, even in the species with reduced V(O(2),max) at high altitude. Metabolic rates during running and energy costs of transport differed to some extent across altitudes but in different ways in the two species. At both test sites, voluntary running by both species was almost exclusively at speeds well within aerobic limits. We conclude that substantial differences in altitude do not necessarily result in differences in aerobic capacity in small mammals and, even if V(O(2),max) is reduced at high altitude, there may be no effect on voluntary running behavior.

  4. Global Investigation of the Mg Atom and ion Layers using SCIAMACHY/Envisat Observations between 70 km and 150 km Altitude and WACCM-MG Model Results

    NASA Technical Reports Server (NTRS)

    Langowski, M.; vonSavigny, C.; Burrows, J. P.; Feng, W.; Plane, J. M. C.; Marsh, D. R.; Janches, Diego; Sinnhuber, M.; Aikin, A. C.

    2014-01-01

    Mg and Mg+ concentration fields in the upper mesosphere/lower thermosphere (UMLT) region are retrieved from SCIAMACHY/Envisat limb measurements of Mg and Mg+ dayglow emissions using a 2-D tomographic retrieval approach. The time series of monthly means of Mg and Mg+ for number density as well as vertical column density in different latitudinal regions are shown. Data from the limb mesosphere-thermosphere mode of SCIAMACHY/Envisat are used, which covers the 50 km to 150 km altitude region with a vertical sampling of 3.3 km and a highest latitude of 82 deg. The high latitudes are not covered in the winter months, because there is no dayglow emission during polar night. The measurements were performed every 14 days from mid-2008 until April 2012. Mg profiles show a peak at around 90 km altitude with a density between 750 cm(exp-3) and 2000 cm(exp-3). Mg does not show strong seasonal variation at mid-latitudes. The Mg+ peak occurs 5-15 km above the neutral Mg peak at 95-105 km. Furthermore, the ions show a significant seasonal cycle with a summer maximum in both hemispheres at mid- and high-latitudes. The strongest seasonal variations of the ions are observed at mid-latitudes between 20-40 deg and densities at the peak altitude range from 500 cm(exp-3) to 6000 cm(exp-3). The peak altitude of the ions shows a latitudinal dependence with a maximum at mid-latitudes that is up to 10 km higher than the peak altitude at the equator. The SCIAMACHY measurements are compared to other measurements and WACCM model results. In contrast to the SCIAMACHY results, the WACCM results show a strong seasonal variability for Mg with a winter maximum, which is not observable by SCIAMACHY, and globally higher peak densities. Although the peak densities do not agree the vertical column densities agree, since SCIAMACHY results show a wider vertical profile. The agreement of SCIAMACHY and WACCM results is much better for Mg+, showing the same seasonality and similar peak densities. However

  5. Energy status and oxidation reduction status in rat liver at high altitude /3.8 km/

    NASA Technical Reports Server (NTRS)

    Reed, R. D.; Pace, N.

    1980-01-01

    Adult male rats were exposed to 3.8-km altitude for intervals ranging from 1 h-60 d. Liver samples were taken under light ether anesthesia and were examined by enzymatic analyses. Within 1-6 h of hypoxic exposure, ATP levels decreased while ADP and AMP levels increased, producing a fall in calculated ATP/ADP and adenylate charge ratios. Concurrently, lactate/pyruvate and alpha-glycerophosphate/dihydroxyacetone phosphate ratios increased markedly. Direct measurements of cellular pyridine nucleotides indicated increased NADH/NAD and NADPH/NADP ratios. Levels of total adenosine phosphates and pyridine nucleotides decreased in a significant accompanying response. Many metabolite levels and calculated ratios returned to near-normal values within 1 week of exposure, indicating secondary intracellular adjustments to hypoxic stress; however, persistence of that stress is reflected in lactate concentrations and both substrate redox ratios. Results support and explore concepts that increased oxidation-reduction status and decreased energy status are primary events during hypoxia.

  6. The distribution of high altitude (70km) ice clouds in the Mars atmosphere from MGS TES limb radiance measurements

    NASA Astrophysics Data System (ADS)

    Clancy, T.; Wolff, M.

    One of the more interesting aspects of the atmospheric temperature profiles retrieved during the Pathfinder descent entry was the detection of cold 80km altitude temperatures below the saturation conditions for CO2 ice formation (Schofield et al., 1997). Disk average measurements of 70-80 km altitudes temperatures from ground-based sub-millimeter CO line observations are only 20K above CO2 saturation temperatures around the Mars Ls = 0 and 180 equinoctial seasons (Clancy, 1999). Clancy and Sandor (1998) suggested the relatively frequent occurrence of CO2 ice clouds in the 70-80 km altitude region, on the basis of the observed cold temperatures, Pathfinder images of blue (small size) ice clouds in the predawn sky, and Mariner 6 and 7 near-IR (4.3 micron) identification of CO2 ice in equatorial limb tangent views around Ls=200 in 1969 (Herr and Pimental, 1970). Before MGS observations, it remained unclear whether CO2 or water ice aerosols are ever present at >60km altitudes. Certainly dust aerosols had been identified at such high altitudes in Mariner 9 (Anderson and Leovy, 1978) and Viking (Jaquin et al., 1986) limb imaging, associated with the 1971 and 1977 global dust storms. The highest detached ice cloud identified from Viking limb data occurred at 55 km tangent altitude, at 16S, 72W and Ls = 176 (Jaquin et al., 1986; recently modeled by Montmessin et al., 2002). This seasonal period and location is actually fairly consistent with 70-80 km detached limb clouds that are observed prominently in the TES solarband limb scans, and appear restricted to fairly specific locations and seasons. The character of these high altitude limb clouds is displayed as a strong peak in scattered light is presented at 70-80 km altitudes, which is not resolved by the TES limb vertical resolution of ˜ 10 km and not detected in the coincident TES thermal IR spectral radiances. It is possible that co-adding of all limb IR spectra associated with TES solarband detections of these clouds

  7. Equatorial ionosphere observations from ionosonde satellite at an altitude of 350 km

    NASA Astrophysics Data System (ADS)

    Kotonaeva, Nadezhda; Danilkin, Nick

    Experimental study of the ionosphere from a MIR MAN SPACE STATUON (MMSS) was held in 1999. The new and interesting information was obtained in the study of the equatorial ionosphere. Critical frequencies and plasma frequencies distributions along the orbit at an altitude of MMSS had the appearance of two distinct peaks (crests) on both sides of the geomagnetic equator during the afternoon and evening local time. This corresponds to a typical daily distribution of plasma frequencies in areas of the equatorial anomaly (EA). The values of the critical frequency on the tops of EA "crest" exceeded the upper limit (16 MHz) of the ionosonde frequency often. In many cases, the measured values significantly exceeded the forecast model IRI. Analysis of the daytime values of the critical frequency on the tops of EA "crests" showed their approximate equality in the peaks of the southern and northern "crests". General analysis of the location of EA "crests" vertices during a night local time in the 1999 spring showed that the coordinates of the "crest" maxima are consistent with the finding of the geomagnetic equator, which corresponds to the theoretical predictions of the model provisions and IRI. MMSS was often lower than the height of the ionosphere maximum near the EA existence. At that time, satellite ionograms were recorded with previously unknown continuous trace of a characteristic shape with large group delay. This group delay is increasing monotonically with frequency increase. The trace was called "retardation of the lower trace" (RLT). The reason for it appearance is the oblique propagation of radio waves in a wide frequency range with the return to the satellite. A special kind of trajectory can be explained by large gradients of the electron density in a region of signal propagation. Gradients of plasma frequencies at the MMSS heights causing RLT were evaluated by a method of a trajectory synthesis. In the daytime they do not exceed 1 MHz / 100km. In the evening

  8. Dayside and nightside magnetic field responses at 780 km altitude to dayside reconnection

    NASA Astrophysics Data System (ADS)

    Snekvik, K.; Østgaard, N.; Tenfjord, P.; Reistad, J. P.; Laundal, K. M.; Milan, S. E.; Haaland, S. E.

    2017-02-01

    During southward interplanetary magnetic field, dayside reconnection will drive the Dungey cycle in the magnetosphere, which is manifested as a two-cell convection pattern in the ionosphere. We address the response of the ionospheric convection to changes in the dayside reconnection rate by examining magnetic field perturbations at 780 km altitude. The Active Magnetosphere and Planetary Electrodynamics Response Experiment data products derived from the Iridium constellation provide global maps of the magnetic field perturbations. Cluster data just upstream of the Earth's bow shock have been used to estimate the dayside reconnection rate. By using a statistical model where the magnetic field can respond on several time scales, we confirm previous reports of an almost immediate response both near noon and near midnight combined with a 10-20 min reconfiguration time of the two-cell convection pattern. The response of the ionospheric convection has been associated with the expansion of the polar cap boundary in the Cowley-Lockwood paradigm. In the original formulation of this paradigm the expansion spreads from noon to midnight in 15-20 min. However, also an immediate global response has been shown to be consistent with the paradigm when the previous dayside reconnection history is considered. In this paper we present a new explanation for how the immediate response can be accommodated in the Cowley-Lockwood paradigm. The new explanation is based on how MHD waves propagate in the magnetospheric lobes when newly reconnected open flux tubes are added to the lobes, and the magnetopause flaring angle increases.

  9. The Distribution of High Altitude (70KM) Ice Clouds in the Mars Atmospere from MGS TES and MOC LIMB Observations

    NASA Astrophysics Data System (ADS)

    Clancy, R. T.; Wolff, M.; Whitney, B.; Cantor, B.

    2004-11-01

    The Pathfinder descent entry detected extremely cold temperatures at 70-100 km altitudes (Schofield et al., 1997), suggesting the possibility of frequent CO2 ice cloud occurrence in the 70-80 km altitude region (Clancy and Sandor, 1998). However, prior to recent MGS limb measurements, it remained unclear whether CO2 or water ice aerosols are ever present at >60 km altitudes. Dust aerosols have been identified at such high altitudes in Mariner 9 (Anderson and Leovy, 1978), Viking (Jaquin et al., 1986), and MGS limb measurements (Clancy, 2003), associated with the 1971, 1977, and 2001 planet-encircling dust storms, respectively. The highest detached ice cloud identified from Viking limb data occurred at a projected tangent altitude of 55km, at 16S, 72W and Ls = 176° (Jaquin et al., 1986; recently modeled by Montmessin et al., 2002). The seasonal period and location of this detached limb cloud appears consistent with 55-75 km detached limb clouds that we have observed as prominent in MGS TES solarband limb scans and MGS MOC wide-angle (WA) limb images (1-3 pm local times). Their occurrence frequency approaches unity at the beginning and end of the aphelion northern summer season on Mars (centered at Ls =30° and 150° ), where they are confined to equatorial (15S-15N) latitudes and two relatively narrow longitude ranges (330-20W and 50-120W). Cloud altitudes of 65-75km are derived from the distribution of projected limb heights. Peak optical (visible) depths are quite significant (0.01) for the low pressure region of formation ( 1 microbar). It remains unclear as to their composition (water or CO2), although coadded MGS thermal IR spectra indicate potential for water ice identification and particle size information. We will present the spatial and temporal distribution of these mesospheric clouds indicated in the MSG TES and MOC visible limb data, and derived vertical profiles of optical depth and particle size based upon a monte carlo spherical RT analysis of the

  10. Seasonal variations of NO and O3 at altitudes of 18.3 and 21.3 km

    NASA Technical Reports Server (NTRS)

    Loewenstein, M.; Savage, H. F.; Whitten, R. C.

    1975-01-01

    Nitric oxide and ozone concentrations have been measured in situ from a high-altitude research aircraft. Data which show the variations of NO and O3 with the time of year are presented for altitudes of 18.3 and 21.3 km. The extreme values of the observed NO concentrations at 21.3 km are 1.2 billion per cu cm in summer and 0.2 billion per cu cm in winter. At 18.3 km the extreme values are 1.6 billion per cu cm in summer and 0.1 billion per cu cm in winter. The smoothed NO seasonal data show a variation of about a factor of 2.5 at 21.3 km and a factor of 4 at 18.3 km. The ozone data show the generally expected magnitude and seasonal variation. We have used a photochemical model employing the measured ozone concentrations, the mean solar zenith angle, and seasonal HNO3 data reported by others to predict the seasonal NO variation at 20 km. The result is a summer-to-winter NO ratio of 2.5 which is in fair agreement with the observed ratios.

  11. Modeling Relativistic Electron Precipitation Bremsstrahlung X-Ray Intensities at 10-100 km Manned Vehicle Altitudes

    NASA Astrophysics Data System (ADS)

    Habash Krause, L.; Gilchrist, B. E.; Nishikawa, K.; Williams, A.

    2013-12-01

    Relativistic electron precipitation (REP) events occur when beams or bunches of relativistic electrons of magnetospheric origin enter the Earth's atmosphere, typically at auroral latitudes. REP events are associated with a variety of space weather effects, including production of transitional and bremsstrahlung radiation, catalytic depletion of stratospheric ozone, and scintillation of transionospheric radio waves. This study examines the intensities of x-rays produced at airliner, manned balloon, and suborbital Reusable Launch Vehicle (sRLV) altitudes. The monoenergetic beam is modeled in cylindrical symmetry using the paraxial ray equation. Bremsstrahlung photon production is calculated using the traditional Sauter-Elwert cross-section, providing x-ray emission spectra differential in energy and angle. Attenuation is computed for a plane-stratified standard atmosphere, and the loss processes include photoionization, Rayleigh and Compton scattering, electron-positron pair production, and photonuclear interaction. Peak altitudes of electron energy deposition and bremsstrahlung x-ray production were calculated for beams of energies from 1 MeV through 100 MeV. The altitude peak of bremsstrahlung deposition was consistently and significantly lower that that of the electron deposition due to the longer mean free paths of x-rays compared to electrons within the atmosphere. For example, for a nadir-directed monoenergetic 5 MeV beam, the peak deposition altitude was calculated to be 42 km, but the resulting bremmstrahlung deposition peaked at 25 km. This has implications for crew and passenger safety, especially with the growth of the space tourism industry that relies on sRLVs with a nominal apogee of 100 km. A survey of results covering the 1-100 MeV spectrum for the three altitude ranges of interest will be presented.

  12. Modeling Relativistic Electron Precipitation Bremsstrahlung X-Ray Intensities at 10-100 km Manned Vehicle Altitudes

    NASA Technical Reports Server (NTRS)

    Krause, L. Habsh; Gilchrist, B. E.; Nishikawa, Ken-Ichi

    2013-01-01

    Relativisitic electron precipitation (REP) events occur when beams or bunches of relativistic electrons of magnetospheric origin enter the Earth's atmosphere, typically at auroral latitudes. REP events are associated with a variety of space weather effects, including production of transitional and bremsstrahlung radiation, catalytic depletion of stratospheric ozone, and scintillation of transionospheric radio waves. This study examines the intensities of x-rays produced at airliner, manned balloon, and space reuseable launch vehicles (sRLVs). The monoenergetic beam is modeled in cylindrical symetry using the paraxial ray equation. Bremsstrahlung photon production is calculated using the traditional Sauter-Elwert cross-section, providing x-ray emission spectra differential in energy and angle. Attenuation is computed for a plane-stratified standard atmosphere, and the loss processes include photoionization, Rayleigh and Compton scattering, electron-positron pair production, and photonuclear interaction. Peak altitudes of electron energy deposition and bremsstrahlung x-ray production were calculated for beams of energies from 1 MeV through 100 MeV. The altitude peak of bremsstrahlung deposition was consistently and significantly lower that that of the electron deposition due to the longer mean free paths of x-rays compared to electrons within the atmosphere. For example, for a nadir-directed monoenergetic 5 MeV beam, the peak deposition altitude was calculated to be 42 km, but the resulting bremsstrahlung deposition peaked at 25 km. This has implications for crew and passenger safety, especially with the growth of the space tourism industry. A survey of results covering the 1-100 MeV spectrum for the three altitude ranges of interest will be presented.

  13. Channel electron multiplier operated on a sounding rocket without a cryogenic vacuum pump from 120 - 75 km altitude

    NASA Astrophysics Data System (ADS)

    Dickson, S.; Gausa, M. A.; Robertson, S. H.; Sternovsky, Z.

    2012-12-01

    We demonstrate that a channel electron multiplier (CEM) can be operated on a sounding rocket in the pulse-counting mode from 120 km to 75 km altitude without the cryogenic evacuation used in the past. Evacuation of the CEM is provided only by aerodynamic flow around the rocket. This demonstration is motivated by the need for additional flights of mass spectrometers to clarify the fate of metallic compounds and ions ablated from micrometeorites and their possible role in the nucleation of noctilucent clouds. The CEMs were flown as guest instruments on the two sounding rockets of the CHAMPS (CHarge And mass of Meteoritic smoke ParticleS) rocket campaign which were launched into the mesosphere in October 2011 from Andøya Rocket Range, Norway. Modeling of the aerodynamic flow around the payload with Direct Simulation Monte-Carlo (DSMC) code showed that the pressure is reduced below ambient in the void beneath an aft-facing surface. An enclosure containing the CEM was placed above an aft-facing deck and a valve was opened on the downleg to expose the CEM to the aerodynamically evacuated region below. The CEM operated successfully from apogee down to ~75 km. A Pirani gauge confirmed pressures reduced to as low as 20% of ambient with the extent of reduction dependent upon altitude and velocity. Additional DSMC simulations indicate that there are alternate payload designs with improved aerodynamic pumping for forward mounted instruments such as mass spectrometers.

  14. Channel electron multiplier operated on a sounding rocket without a cryogenic vacuum pump from 120 to 80 km altitude

    NASA Astrophysics Data System (ADS)

    Dickson, Shannon; Gausa, Michael; Robertson, Scott; Sternovsky, Zoltan

    2013-04-01

    We demonstrate that a channel electron multiplier (CEM) can be operated on a sounding rocket in the pulse-counting mode from 120 km to 80 km altitude without the cryogenic evacuation used in the past. Evacuation of the CEM is provided only by aerodynamic flow around the rocket. This demonstration is motivated by the need for additional flights of mass spectrometers to clarify the fate of metallic compounds and ions ablated from micrometeorites and their possible role in the nucleation of noctilucent clouds. The CEMs were flown as guest instruments on two sounding rockets to the mesosphere. Modeling of the aerodynamic flow around the payload with Direct Simulation Monte-Carlo (DSMC) code showed that the pressure is reduced below ambient in the void behind (relative to the direction of motion) an aft-facing surface. An enclosure containing the CEM was placed forward of an aft-facing deck and a valve was opened during flight to expose the CEM to the aerodynamically evacuated region behind it. The CEM operated successfully from apogee down to ∼80 km. A Pirani gauge confirmed pressures reduced to as low as 20% of ambient with the extent of reduction dependent upon altitude and velocity. Additional DSMC simulations indicate that there are alternate payload designs with improved aerodynamic pumping for forward mounted instruments such as mass spectrometers.

  15. Relationship of O(+) Field-Aligned Flows and Densities to Convection Speed in the Polar Cap at 5000 km Altitude

    NASA Technical Reports Server (NTRS)

    Stevenson, B. A.; Horwitz, J. L.; Creel, B.; Elliott, H. A.; Comfort, R. H.; Su, Y. J.; Moore, T. E.; Craven, P. D.

    1999-01-01

    Measurements of thermal O(+) ion number fluxes, densities, field-aligned velocities, and convective velocities from the Thermal Ion Dynamics Experiment (TIDE) on POLAR obtained near 5000 km altitude over the Southern hemisphere are examined. We find that the O(+) parallel velocities and densities are strongly related to the convection speeds. The polar cap densities decrease rapidly with convection speed, with a linear least square fit formula to bin averaged data giving the relationship log(N(sub (sub _)O(+))) = -0.33* V(sub (sub _)conv)) + 0.07, with a linear regression coefficient of r = -0.96. The parallel bulk flow velocities are on average slightly downward (0 - 2 km/s) for V(sub (sub _)conv) < 2.5 km/s, but tend to be upward (0 - 4 km/s) for average V(sub (sub _)conv) > 2.5 km/s. We interpret these relationships in terms of the Cleft Ion Fountain paradigm [e.g., Horwitz and Lockwood, 1985]. The densities decline with convection speed owing to increased spreading and resulting dilution from the restricted cleft source over the polar cap area with convection speed. The parallel velocities tend to be downward for low convection speeds because they fall earthward after initial cleft injection at shorter distances into the polar cap for low convection speeds. At the higher convection speeds, the initially-upward flows are transported further into the polar cap and thus occupy a larger area of the polar cap.

  16. Cloud Microphysics in Hurricane Outflows: Observations in 'Bonnie' (1998) at 12 km Altitude

    NASA Technical Reports Server (NTRS)

    Pueschel, Rudolf F.; Hallett, J.; Strawa, A. W.; Ferry, G. V.; Bui, T. P.; Condon, Estelle P. (Technical Monitor)

    2000-01-01

    The water balance of a hurricane is controlled by boundary layer inflow, near vertical motion in the eyewall causing coalescence precipitation at above and residual ice precipitation at below freezing temperatures, and cirrus outflow at below -40 C aloft. In this paper we address the question of efficiency of water removal by this cirrus outflow which is important for the release of latent heat at high altitudes and its role in the dynamic flow at that level. During NASA's 1998 Convection and Moisture Experiment campaign we acquired microphysical outflow data in order to (1) determine the release and redistribution of latent heat near the top of hurricanes, (2) aid in TRMM algorithm development for remote sensing of precipitation, and (3) determine the optical/radiative characteristics of hurricane outflow. The data were acquired with Particle Measuring Systems two dimensional imaging spectrometers. On 23 August and again during the hurricane's landfall on 26 August, 1998, the NASA DC-8 aircraft penetrated hurricane 'Bonnie' four times each near 200 hPa pressure altitude. The eye crossing times were determined by (1) zero counts of cloud particles, (2) approximately 5 C increases in static and potential temperatures, and (3) minima in speeds and changes of direction of horizontal winds. The vertical winds showed shear between -6 m per second and +4 m per second and tangential winds approached 30 m per second in the eyewall. The particle volumes in the eyewall (determined by the pixels the particles shadowed in the direction of flight [x-direction] and normally to it by the number of diodes that they shadowed [y-direction]) ranged between 0.5 and 5.0 cubic centimeters per cubic meter. With a particle density near 0.2 g per cubic centimeter (determined from in situ melting and evaporation on a surface collector), the 1.0 g per meter corresponding mass of cloud ice ranged between 0.27 and 2.7 g per kilograms yielding horizontal fluxes between 8.1 and 81 g per square

  17. Range Reference Atmosphere 0-70 km Altitude, Barking Sands, Hawaii

    DTIC Science & Technology

    1983-12-01

    TABLE E. LIST OF PRIMARY PHYSICAL CONSTANTS P 0 = standard atmospheric pressure at sea level = 1.013250 x 10~ Newton ~m2 = 2116.22 lb/ft2 p0 = standard...S.D. MECAN KM P8 "a DEG K DEG K 0:0 K DCG K .000 22.139 2.701 .05 301.88 1.39 .49 292.17 2.0c -.48 329. 329. .005 22.090 2.694 .05 3c0.85 1.39 .49

  18. The latitudinal distribution of ozone to 35 km altitude from ECC ozonesonde observations, 1982-1990

    NASA Technical Reports Server (NTRS)

    Komhyr, W. D.; Oltmans, S. J.; Lathrop, J. A.; Kerr, J. B.; Matthews, W. A.

    1994-01-01

    Electrochemical concentration cell (ECC) ozone-sonde observations, made in recent years at ten stations whose locations range from the Arctic to Antarctica, have yielded a self-consistent ozone data base from which mean seasonal and annual latitudinal ozone vertical distributions to 35 km have been derived. Ozone measurement uncertainties are estimated, and results are presented in the Bass-Paur (1985) ozone absorption coefficient scale adopted for use with Dobson ozone spectrophotometers January 1, 1992. The data should be useful for comparison with model calculations of the global distribution of atmospheric ozone, for serving as apriori statistical information in deriving ozone vertical distributions from satellite and Umkehr observations, and for improving the satellite and Umkehr ozone inversion algorithms. Attention is drawn to similar results based on a less comprehensive data set published in Ozone in the Atmosphere, Proceedings of the 1988 Quadrennial Ozone Symposium where errors in data tabulations occurred for three of the stations due to inadvertent transposition of ozone partial pressure and air temperature values.

  19. Asymmetric penetration of solar wind perturbations down to 400-km altitudes at Mars observed by Mars Global Surveyor

    NASA Astrophysics Data System (ADS)

    Matsunaga, K.; Seki, K.; Hara, T.; Brain, D. A.

    2012-12-01

    Since Mars has no intrinsic global magnetic field, the exchange of energy, momentum, and material with the planet takes place through interaction between the solar wind and the Martin upper atmosphere. It is thought that solar wind encountering Mars can penetrate into the point where the solar wind dynamic pressure and the plasma thermal pressure in the Martin ionosphere are almost balanced and the solar wind flow is deflected around the boundary. However, the actual interaction can be complicated, since both plasma processes and the existence of crustal magnetic fields can modify the structure of the boundary. The Kelvin-Helmholtz (K-H) instability at the Martian ionopause is one of important candidate process to cause the modification. The dDistribution of ionopause surface waves generated by the K-H instability can should exhibit a clear asymmetry between hemispheres of upward and downward solar wind motional electric fields [e.g., Terada et al., 2002]. It is also suggested that the crustal magnetic fields can locally push the MPB (magnetic pileup boundary) upward [e.g., Brain et al., 2003]. It is also reported that the boundary between the solar wind and Martian ionosphere is located at an altitude of 380 km on average in the dayside [e.g., Mitchell et al., 2001]. However, this boundary location can change significantly depending on solar wind conditions. While it is considered that the solar wind can penetrate to lower altitudes than usual when the solar wind pressure is high, the frequency of the solar wind penetration and its quantitative dependence on the solar wind conditions are not yet well understood. In this study, we focused on penetration of solar wind electromagnetic disturbances, which are a characteristic feature of the shocked solar wind (magnetosheath), down to 400-km altitude at Mars. Using Mars Global Surveyor (MGS) data, we investigated the observational frequency and characteristics of the penetration events. We used data from the MGS

  20. Variation of electron and ion density distribution along Earth's magnetic field line deduced from whistler mode (wm) sounding of image/rpi satellite below altitude 5000 km

    NASA Astrophysics Data System (ADS)

    Hazra, Susmita

    This thesis provides a detailed survey and analysis of whistler mode (WM) echoes observed by IMAGE/RPI satellite during the years 2000-2005 below the altitude of 5000 km. Approximately 2500 WM echoes have been observed by IMAGE during this period. This includes mostly specularly reflected whistler mode (SRWM) echoes and ~400 magnetospherically reflected whistler mode (MRWM) echoes. Stanford 2D raytracing simulations and the diffusive equilibrium density model have been applied to 82 cases of MRWM echoes, observed during August-December of the year 2005 below 5000 km to determine electron and ion density measurements along Earth's magnetic field line. These are the first results of electron and ion density measurements from WM sounding covering L-shells ~1.6-4, a wide range of geomagnetic conditions (Kp 0+ to 7), and during solar minima (F10.2~70-120) in the altitude range 90 km to 4000 km. The electron and ion density profiles obtained from this analysis were compared with in situ measurements on IMAGE (passive recording; electron density (Ne)), DMSP (~850 km; Ne and ions), CHAMP (~350 km; Ne), Alouette (~500-2000 km; Ne and ions), ISIS-1, 2 (~600-3500 km; Ne, ions), AE (~130-2000 km; ions) satellites, bottom side sounding from nearby ionosonde stations (Ne), and those by GCPM (Global Core Plasma Model), IRI-2012 (International Reference Ionosphere). Based on this analysis it is found that: (1) Ne shows a decreasing trend from L-shell 1.6 to 4 on both the day and night sides of the plasmasphere up to altitude ~1000 km, which is also confirmed by the GCPM and IRI-2012 model. (2) Above ~2000 km altitude, GCPM underestimates Ne by ~30-90% relative to RPI passive measurements, WM sounding results. (3) Below 1500 km, the Ne is higher at day side than night side MLT (Magnetic Local Time). Above this altitude, significant MLT dependence of electron density is not seen. (4) Ion densities from WM sounding measurements are within 10-35% of those from the Alouette, AE, and

  1. Analysis of the nature of excessive cosmic radiation in the area of the Brazilian magnetic anomaly at altitudes 250-500km, from Kosmos-225 satellite data

    NASA Technical Reports Server (NTRS)

    Raychenko, L. V.

    1974-01-01

    Results are presented from a study of the region of anomalous cosmic radiation in the area of the Brazilian magnetic anomaly at the altitudes 250-500 km, using data measurements taken on the Kosmos-225 satellite (14-29 June 1968). The existence of a stable intensity anomaly discovered in the experiments on the second and third Soviet spacecraft-satellites is confirmed. The total vector of the geomagnetic field at different altitudes was compared with isoline maps. An altitude profile of the South Atlantic anomaly of radiation intensity was obtained, using data from the same instrument. The nature of the anomalies in cosmic radiation intensity over the regions of negative magnetic anomalies is discussed.

  2. Temperature characteristics at altitudes of 5-80 km with a self-calibrated Rayleigh-rotational Raman lidar: A summer case study

    NASA Astrophysics Data System (ADS)

    Li, Yajuan; Lin, Xin; Yang, Yong; Xia, Yuan; Xiong, Jun; Song, Shalei; Liu, Linmei; Chen, Zhenwei; Cheng, Xuewu; Li, Faquan

    2017-02-01

    Temperature profiles at altitudes of 5-80 km are obtained with a self-calibrated Rayleigh-rotational Raman lidar over Wuhan, China (30.5°N, 114.5°E). By using the synchronous Rayleigh lidar temperature, rotational Raman temperature in the lower atmosphere could be calibrated and retrieved, which is free of other instruments (like local radiosondes). The results are comparable to the radiosonde calibration method. Based on the self-calibration approach, one-night (August 4-5, 2014) lidar temperature profiles are presented with radiosondes, NRLMSISE-00 model and TIMED/SABER data. Some interesting temperature characteristics have been present for studies of waves propagating from near ground level into the mesosphere. Temperature perturbations are found to increase exponentially with a scale height of 10 km. The wavy structure shows minimal perturbations ('nodes') at some altitudes of 39, 52, 64 and 73 km. Dominant wavelengths and temperature variations are also analyzed at different time and altitudes. By comparison of the temperature and associate perturbations from the tropopause up to the stratopause, different amplitudes, phase fronts and vertical wavelengths are discovered as well. These discoveries indicate that some waves may originate in the lower atmosphere and propagate upward with decreasing static stability.

  3. Cape Kennedy Wind Component Statistics Monthly and Annual Reference Periods for All Flight Azimuths from 0 to 70 KM Altitude

    NASA Technical Reports Server (NTRS)

    Brown, S. C.

    1969-01-01

    Head-, tail-, and cross-wind component speeds for Cape Kennedy are tabulated for all flight azimuths for altitudes from 0 to 70 kilometers by monthly and annual reference periods. Wind speeds are given for 11 selected percentiles ranging from 0.135 percent to 99.865 percent for each reference period.

  4. Sildenafil does not improve steady state cardiovascular hemodynamics, peak power, or 15-km time trial cycling performance at simulated moderate or high altitudes in men and women.

    PubMed

    Kressler, Jochen; Stoutenberg, Mark; Roos, Bernard A; Friedlander, Anne L; Perry, Arlette C; Signorile, Joseph F; Jacobs, Kevin A

    2011-12-01

    Sildenafil improves oxygen delivery and maximal exercise capacity at very high altitudes (≥ 4,350 m), but it is unknown whether sildenafil improves these variables and longer-duration exercise performance at moderate and high altitudes where competitions are more common. The purpose of this study was to determine the effects of sildenafil on cardiovascular hemodynamics, arterial oxygen saturation (SaO(2)), peak exercise capacity (W (peak)), and 15-km time trial performance in endurance-trained subjects at simulated moderate (MA; ~2,100 m, 16.2% F(I)O(2)) and high (HA; ~3,900 m, 12.8% F(I)O(2)) altitudes. Eleven men and ten women completed two HA W (peak) trials after ingesting placebo or 50 mg sildenafil. Subjects then completed four exercise trials (30 min at 55% of altitude-specific W (peak) + 15-km time trial) at MA and HA after ingesting placebo or 50 mg sildenafil. All trials were performed in randomized, counterbalanced, and double-blind fashion. Sildenafil had little influence on cardiovascular hemodynamics at MA or HA, but did result in higher SaO(2) values (+3%, p < 0.05) compared to placebo during steady state and time trial exercise at HA. W (peak) at HA was 19% lower than SL (p < 0.001) and was not significantly affected by sildenafil. Similarly, the significantly slower time trial performance at MA (28.1 ± 0.5 min, p = 0.016) and HA (30.3 ± 0.6 min, p < 0.001) compared to SL (27.5 ± 0.6 min) was unaffected by sildenafil. We conclude that sildenafil is unlikely to exert beneficial effects at altitudes <4,000 m for a majority of the population.

  5. Estimation of precipitable water vapour using kinematic GNSS precise point positioning over an altitude range of 1 km

    NASA Astrophysics Data System (ADS)

    Webb, S. R.; Penna, N. T.; Clarke, P. J.; Webster, S.; Martin, I.

    2013-12-01

    The estimation of total precipitable water vapour (PWV) using kinematic GNSS has been investigated since around 2001, aiming to extend the use of static ground-based GNSS, from which PWV estimates are now operationally assimilated into numerical weather prediction models. To date, kinematic GNSS PWV studies suggest a PWV measurement agreement with radiosondes of 2-3 mm, almost commensurate with static GNSS measurement accuracy, but only shipborne experiments have so far been carried out. As a first step towards extending such sea level-based studies to platforms that operate at a range of altitudes, such as airplanes or land based vehicles, the kinematic GNSS estimation of PWV over an exactly repeated trajectory is considered. A data set was collected from a GNSS receiver and antenna mounted on a carriage of the Snowdon Mountain Railway, UK, which continually ascends and descends through 950 m of vertical relief. Static GNSS reference receivers were installed at the top and bottom of the altitude profile, and derived zenith wet delay (ZWD) was interpolated to the altitude of the train to provide reference values together with profile estimates from the 100 m resolution runs of the Met Office's Unified Model. We demonstrate similar GNSS accuracies as obtained from previous shipborne studies, namely a double difference relative kinematic GNSS ZWD accuracy within 14 mm, and a kinematic GNSS precise point positioning ZWD accuracy within 15 mm. The latter is a more typical airborne PWV estimation scenario i.e. without the reliance on ground-based GNSS reference stations. We show that the kinematic GPS-only precise point positioning ZWD estimation is enhanced by also incorporating GLONASS observations.

  6. Relationships between stratospheric clear air turbulence and synoptic meteorological parameters over the western United States between 12-20 km altitude

    NASA Technical Reports Server (NTRS)

    Scoggins, J. R.; Clark, T. L.; Possiel, N. C.

    1975-01-01

    Procedures for forecasting clear air turbulence in the stratosphere over the western United States from rawinsonde data are described and results presented. Approaches taken to relate meteorological parameters to regions of turbulence and nonturbulence encountered by the XB-70 during 46 flights at altitudes between 12-20 km include: empirical probabilities, discriminant function analysis, and mountainwave theory. Results from these techniques were combined into a procedure to forecast regions of clear air turbulence with an accuracy of 70-80 percent. A computer program was developed to provide an objective forecast directly from the rawinsonde sounding data.

  7. A theoretical framework for the changing spectral properties of meter-scale Farley-Buneman waves between 90 and 125 km altitudes

    NASA Astrophysics Data System (ADS)

    St.-Maurice, Jean-Pierre; Chau, Jorge L.

    2016-10-01

    Stimulated by recent observations described in a companion paper, we have revisited existing theories of the Farley-Buneman instability throughout the altitude range 90 to 125 km. We have assumed that the irregularities detected by radars at a given altitude are dominated by structures moving at the threshold speed in a direction associated with maximum linear growth rate conditions. We included recent nonisothermal electron and ion theories, which can modify threshold speeds by considerable amounts. We included altitude-dependent models of ion and electron temperature and of the ion motion in the phase velocity calculations. Our treatment of the instability explains why some spectra are slow (Doppler shifts typically 200 m/s) and narrow, while others are fast (1500 m/s or close to the E × B) and narrow. These narrow spectra have all the characteristics of what has been labeled as "Type III" and "Type IV" in the past. Our calculations also offer an explanation for the observation of a strong asymmetry in the number of events with positive Doppler shifts near the nominal ion-acoustic speed and those with negative Doppler shifts of the same magnitude.

  8. Correcting Mars Global Surveyor Thermal Emission Spectrometer (MGS-TES) High Altitude (40 - 65 km) Temperature Retrievals for Instrumental Correlated Noise and Biases

    NASA Astrophysics Data System (ADS)

    McConnochie, T. H.; Smith, M. D.

    2011-12-01

    Mars Global Surveyor Thermal Emission Spectrometer (MGS-TES) nadir-soundings have been used to derive atmospheric temperatures up to roughly 40 km [Conrath et al., JGR 105 2000, Smith et al., JGR 106, 2001], and MGS-TES limb soundings have been used to extend the atmospheric temperature data set to > 60 km in altitude [Smith et al., JGR 106, 2001]. The ~40 - ~65 km altitude range probed by the MGS-TES limb sounding is particularly important for capturing key dynamical features such as the warm winter polar mesosphere [e.g., Smith et al., JGR 106, 2001; McCleese et al., Nature Geoscience 1, 2008], and the response of thermal tides to dust opacity [e.g. Wilson and Hamilton, J. Atmos. Sci. 53, 1996]. Thus accurate and precise temperature profiles at these altitudes are particularly important for constraining global circulation models. They are also critical for interpreting observations of mesospheric condensate aerosols [e.g., Määttänen et al., Icarus 209, 2010; McConnochie et al., Icarus 210, 2010)]. We have indentified correlated noise components in the MGS-TES limb sounding radiances that propagate into very large uncertainties in the retrieved temperatures. We have also identified a slowly varying radiance bias in the limb sounding radiances. Note that the nadir-sounding-based MGS-TES atmospheric temperatures currently available from the Planetary Data System are not affected by either of these issues. These two issues affect the existing MGS-TES limb sounding temperature data set are as follows: Considering, for example, the 1.5 Pascal pressure level (which typically falls between 50 and 60 km altitude), correlated-noise induced standard errors for individual limb-sounding temperature retrievals were 3 - 5 K in Mars Year 24, rising to 5 - 15 K in Mars Year 25 and 10 - 15 K in Mars Year 26 and 27. The radiance bias, although consistent on ~10-sol time scales, is highly variable over the course of the MGS-TES mission. It results in temperatures (at the 1

  9. Global circulation of the Earth's atmosphere at altitudes from 0 to 135 Km simulated with the ARM model. Consideration of the solar activity contribution

    NASA Astrophysics Data System (ADS)

    Krivolutsky, A. A.; Cherepanova, L. A.; Dement'eva, A. V.; Repnev, A. I.; Klyuchnikova, A. V.

    2015-11-01

    The results of simulations of the global circulation and temperature regime in the altitude range from the lower tropospheric layers to 135 km are presented. They were obtained with the Atmospheric Research Model (ARM), an advanced modification of a version of the Cologne Middle Atmosphere Model (COMMA). The ARM is characterized by higher spatial resolution and better parameterizations of the radiation sources and heat sinks. At the lower boundary of the model, wavy sources of perturbations, which are caused by internal gravity waves and planetary waves, are specified. The results of the modeling of the global temperature and wind fields for the mean solar activity level are presented, and their changes, which are caused by variations of the UV-radiation fluxes in the solar activity cycle and by solar proton flares, are also considered.

  10. Three-micron extinction of the Titan haze in the 250-700 km altitude range: Possible evidence of a particle-aging process

    NASA Astrophysics Data System (ADS)

    Courtin, Régis; Kim, Sang Joon; Bar-Nun, Akiva

    2015-01-01

    Context. The chemical nature of the Titan haze is poorly understood. The investigation carried out by the Cassini-Huygens suite of instruments is bringing new insights into this question. Aims: This work aims at deriving the vertical variation of the spectral structure of the 3.3-3.4 μm absorption feature of the Titan haze from Cassini VIMS solar occultation data recorded between 250 and 700 km altitude. Methods: We computed the transmittance of Titan's atmosphere using a spherical shell model and a radiative transfer code including the influence of CH4, CH3D, and C2H6, as well as the effects of absorption and scattering by the haze particles. We derived the haze extinction from a comparison of the synthetic spectra with the VIMS solar occultation spectra. Results: We find a marked change in the relative amplitudes of the 3.33 and 3.38 μm features, which are characteristic of aromatic (double C=C chains or rings) or aliphatic (single C-C chains) structural groups, respectively. The pseudo-ratio of aromatics to aliphatics (uncorrected for the absolute band strengths) varies from 3.3 ± 1.9 at 580-700 km to 0.9 ± 0.1 at 350-450 km, and is 0.5 ± 0.1 around 250 km. The structural change from the aromatic to the aliphatic type between 580 and 480 km appears to correspond to a spontaneous aging of the particles - a transition between unannealed and hardened particles - while the further decrease of the pseudo-ratio of aromatics to aliphatics below 480 km may be related to the coating of the core particles by condensates such as heavy alkanes. VIMS transmission spectra data are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/573/A21

  11. Observations of a Breakdown of a Mountain Wave Near 84 km Altitude Over Cerro Pachon Chile from the Andes Lidar Observatory

    NASA Astrophysics Data System (ADS)

    Hecht, J. H.; Gelinas, L. J.; Rudy, R. J.; Walterscheid, R. L.; Taylor, M. J.; Pautet, P. D.; Fritts, D. C.; Smith, S. M.; Franke, S. J.; Mlynczak, M. G.

    2015-12-01

    Mountain waves are produced by flow over orography. They propagate almost vertically, and are characterized by nearly zero velocity phase speed. The altitude to which they typically propagate is not well documented. They are thought to mainly dissipate by absorption in a critical layer although large-amplitude wave breakdown is also thought to occur. There have been almost no direct observations of the breakdown of mountain waves in the upper mesosphere and lower thermosphere. The region over Cerro Pachon Chile (a 2715 meter mountain in the Andes where large astronomical telescopes are located) is especially favorable to the production of mountain waves. In 2009 Smith and colleagues reported on the first observations of such waves propagating into the mesopause region (85 to 95 km) from El Leoncito Argentina, where waves over Cerro Pachon could be seen using airglow observations. The Aerospace Corporation's Nightglow Imager (ANI) is located at the Andes Lidar Observatory near the crest of Cerro Pachon. ANI observes nighttime OH emission (near 1.6 microns) every 2 seconds over an approximate 73 degree field of view. ANI had previously been used to the breakdown of Kelvin-Helmholtz instability features not associated with a specific gravity wave. Here we present OH airglow observations, originating near 84 km, from 22 UT to 3 UT on 8/9 July 2012 that show the breakdown of a mountain wave into instability features that subsequently dissipate into turbulence. These multi-hour observations provide the most detailed images to date of the breakdown of a mountain wave. The causes for, and the results of, the breakdown of this mountain wave are discussed.

  12. Storm-time changes of geomagnetic field at MAGSAT altitudes (325-550 Km) and their comparison with changes at ground locations

    NASA Technical Reports Server (NTRS)

    Parada, N. D. J. (Principal Investigator); Kane, R. P.; Trivedi, N. B.

    1983-01-01

    The values of H, X, Y, Z at MAGSAT altitudes were first expressed as residuals delta H, delta X, delta Y, delta Z after subtracting the model HMD, XMD, YMD, ZMC. The storm-time variations of H showed that delta H (Dusk) was larger (negative) than delta H (Dawn) and occurred earlier, indicating a sort of hysteresis effect. Effects at MAGSAT altitudes were roughly the same (10% accuracy) as at ground, indicating that these effects were mostly of magnetospheric origin. The delta Y component also showed large storm-time changes. The latitudinal distribution of storm-time delta H showed north-south asymmetries varying in nature as the storm progressed. It seems that the central plane of the storm-time magnetospheric ring current undergoes latitudinal meanderings during the course of the storm.

  13. Venus Altitude Cycling Balloon

    NASA Astrophysics Data System (ADS)

    de Jong, M. L.

    2015-04-01

    A novel balloon concept is demonstrated that uses mechanical compression as altitude control mechanism to sustain long duration balloon probe flight in the cloud level region of Venus’ atmosphere between 45 and 58 km altitude.

  14. Aircraft measurements made during the spring maximum of ozone over Hawaii: Peroxides, CO, O3, NOy, condensation nuclei, selected hydrocarbons, halocarbons, and alkyl nitrates between 0.5 and 9 km altitude

    NASA Astrophysics Data System (ADS)

    Ridley, B. A.; Atlas, E. L.; Walega, J. G.; Kok, G. L.; Staffelbach, T. A.; Greenberg, J. P.; Grahek, F. E.; Hess, P. G.; Montzka, D. D.

    1997-08-01

    Between April 22 and May 11, 1992, ten flights of the University of Wyoming King Air were made during the maximum in tropospheric ozone over the central North Pacific Ocean in conjunction with the spring intensive of the second Mauna Loa Observatory Photochemistry Experiment. During the first week of flights, an episode of remarkably large total reactive nitrogen, NOy (˜2 ppbv) persisted in the 5-9 km altitude region for 3-4 days. Backtrajectory calculations combined with the trace gas and aerosol measurements confirm that its source was due primarily to export from northern latitude continental surface regions. The total amount of odd nitrogen transported over Hawaii during this event was estimated to be 1-2% of the annual emissions from subsonic aircraft or from stratospheric input. Throughout the measurement program layers of elevated O3, NOy, condensation nuclei (CN), and other species were frequently found between the onset of the marine boundary layer temperature inversion and 4-5 km altitude. Structure and strong gradients within these layers contribute to the daily variations seen at the 3.4 km elevation of the Mauna Loa Observatory during the nighttime downslope flow. The dryness of these low-altitude layers and the calculated air mass trajectories indicate that export from northern latitudes occurred mainly with subsidence to the Hawaii region rather than from transit just above the boundary layer inversion. There was no evidence of recent stratospheric input to the altitude region sampled below 9 km. However, the observations cannot distinguish whether O3 input from the stratosphere occurred earlier in the air mass histories at higher latitudes. Fine vertical scale anticorrelations between CN and O3 or NOy were also often observed particularly in the last week of the program when NOy mixing ratios were more typical of the remote troposphere. These features are attributed to new particle formation near the tops of cloud convection episodes and they

  15. Ground-based neutral gas environment simulation related to material degradation phenomena in the orbital altitudes of 200-500 km

    NASA Astrophysics Data System (ADS)

    Tagawa, Masahito; Yokota, Kumiko; Oyabu, Takashi; Ohira, Junki; Watanabe, Daiki; Yamasaki, Yuki

    The exterior surface of the spacecraft was covered by thermal control materials that mainly made of polymeric materials such as polyimide or fluorinated ethylenepropylene (FEP). It has been widely known that materials in low Earth orbit (LEO) are subjected to severe degradation caused by various space environmental factors. There are many environmental factors in space, however, atomic oxygen (AO) is one of the major concerns on the material degradation in LEO. The reaction mechanism of AO with materials has been studied by ground-based experiments using laser-detonation hyperthermal beam source, which enables to accelerate the electrically neutral AO up to 8 km/s (orbital velocity of spacecraft). Besides the AO-induced material degradation of hydrocarbons, it has been suspected that the chemically inert heavy molecules, such as N2, have influenced material erosions. In this presentation, effects of Ar collision (simulating the collision energy of N2 in space), sample temperature and vacuum ultraviolet exposures on the AO-induced material erosion were studied. Not only the mass-loss effect, but also the difference in surface chemistry by AO or Ar bombardment will also be presented.

  16. 43 CFR 3.13 - Report of field officer.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 43 Public Lands: Interior 1 2012-10-01 2011-10-01 true Report of field officer. 3.13 Section 3.13 Public Lands: Interior Office of the Secretary of the Interior PRESERVATION OF AMERICAN ANTIQUITIES § 3.13 Report of field officer. The field officer in charge of land owned or controlled by the...

  17. 43 CFR 3.13 - Report of field officer.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 43 Public Lands: Interior 1 2014-10-01 2014-10-01 false Report of field officer. 3.13 Section 3.13 Public Lands: Interior Office of the Secretary of the Interior PRESERVATION OF AMERICAN ANTIQUITIES § 3.13 Report of field officer. The field officer in charge of land owned or controlled by the...

  18. 43 CFR 3.13 - Report of field officer.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 43 Public Lands: Interior 1 2011-10-01 2011-10-01 false Report of field officer. 3.13 Section 3.13 Public Lands: Interior Office of the Secretary of the Interior PRESERVATION OF AMERICAN ANTIQUITIES § 3.13 Report of field officer. The field officer in charge of land owned or controlled by the...

  19. 43 CFR 3.13 - Report of field officer.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 43 Public Lands: Interior 1 2010-10-01 2010-10-01 false Report of field officer. 3.13 Section 3.13 Public Lands: Interior Office of the Secretary of the Interior PRESERVATION OF AMERICAN ANTIQUITIES § 3.13 Report of field officer. The field officer in charge of land owned or controlled by the...

  20. 43 CFR 3.13 - Report of field officer.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 43 Public Lands: Interior 1 2013-10-01 2013-10-01 false Report of field officer. 3.13 Section 3.13 Public Lands: Interior Office of the Secretary of the Interior PRESERVATION OF AMERICAN ANTIQUITIES § 3.13 Report of field officer. The field officer in charge of land owned or controlled by the...

  1. High-Altitude Illness

    MedlinePlus

    ... high-altitude illness:Acute mountain sicknessHigh-altitude pulmonary edema (also called HAPE), which affects the lungsHigh-altitude cerebral edema (also called HACE), which affects the brainThese illnesses ...

  2. 41 CFR 60-3.13 - Affirmative action.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 41 Public Contracts and Property Management 1 2010-07-01 2010-07-01 true Affirmative action. 60-3.13 Section 60-3.13 Public Contracts and Property Management Other Provisions Relating to Public... 3-UNIFORM GUIDELINES ON EMPLOYEE SELECTION PROCEDURES (1978) General Principles §...

  3. 40Km Into Lebanon,

    DTIC Science & Technology

    1987-07-01

    answer to the difficulties in Palestine, London organized a study of the problem under Lord Peel , a for- mer Secretary of State for India, who in 1937...issued the report of the Commission bearing his name. As Peel saw it, the only solution was to partition Palestine between the two communities. The...minority suggestions. The majority 22 40Km into Lebanon report recommended partition with an economic union, much as Peel had proposed in 1937. A

  4. 12 CFR 3.13 - Relation to other actions.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... proceedings under 12 U.S.C. 1818 (b) or (c) (12 CFR 19.0 through 19.21), or as a condition for approval of an... 12 Banks and Banking 1 2011-01-01 2011-01-01 false Relation to other actions. 3.13 Section 3.13 Banks and Banking COMPTROLLER OF THE CURRENCY, DEPARTMENT OF THE TREASURY MINIMUM CAPITAL...

  5. 12 CFR 3.13 - Relation to other actions.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... proceedings under 12 U.S.C. 1818 (b) or (c) (12 CFR 19.0 through 19.21), or as a condition for approval of an... 12 Banks and Banking 1 2013-01-01 2013-01-01 false Relation to other actions. 3.13 Section 3.13 Banks and Banking COMPTROLLER OF THE CURRENCY, DEPARTMENT OF THE TREASURY MINIMUM CAPITAL...

  6. High Altitude Launch for a Practical SSTO

    NASA Technical Reports Server (NTRS)

    Landis, Geoffrey A.; Denis, Vincent

    2003-01-01

    Existing engineering materials allow the construction of towers to heights of many kilometers. Orbital launch from a high altitude has significant advantages over sea-level launch due to the reduced atmospheric pressure, resulting in lower atmospheric drag on the vehicle and allowing higher rocket engine performance. high-altitude launch sites are particularly advantageous for single-stage to orbit (SSTO) vehicles, where the payload is typically 2% of the initial launch mass. An earlier paper enumerated some of the advantages of high altitude launch of SSTO vehicles. In this paper, we calculate launch trajectories for a candidate SSTO vehicle, and calculate the advantage of launch at launch altitudes 5 to 25 kilometer altitudes above sea level. The performance increase can be directly translated in to increased payload capability to orbit, ranging from 5 to 20% increase in the mass to orbit. For a candidate vehicle with an initial payload fraction of 2% of gross lift-off weight, this corresponds to 31 % increase in payload (for 5-km launch altitude) to 122% additional payload (for 25-km launch altitude).

  7. Gravity Waves Near 300 km Over the Polar Caps

    NASA Technical Reports Server (NTRS)

    Johnson, F. S.; Hanson, W. B.; Hodges, R. R.; Coley, W. R.; Carignan, G. R.; Spencer, N. W.

    1995-01-01

    Distinctive wave forms in the distributions of vertical velocity and temperature of both neutral particles and ions are frequently observed from Dynamics Explorer 2 at altitudes above 250 km over the polar caps. These are interpreted as being due to internal gravity waves propagating in the neutral atmosphere. The disturbances characterized by vertical velocity perturbations of the order of 100 m/s and horizontal wave lengths along the satellite path of about 500 km. They often extend across the entire polar cap. The associated temperature perturbations indicate that the horizontal phase progression is from the nightside to the dayside. Vertical displacements are inferred to be of the order of 10 km and the periods to be of the order of 10(exp 3) s. The waves must propagate in the neutral atmosphere, but they usually are most clearly recognizable in the observations of ion vertical velocity and ion temperature. By combining the neutral pressure calculated from the observed neutral concentration and temperature with the vertical component of the neutral velocity, an upward energy flux of the order of 0.04 erg/sq cm-s at 250 km has been calculated, which is about equal to the maximum total solar ultraviolet heat input above that altitude. Upward energy fluxes calculated from observations on orbital passes at altitudes from 250 to 560 km indicate relatively little attenuation with altitude.

  8. Athletes at High Altitude

    PubMed Central

    Khodaee, Morteza; Grothe, Heather L.; Seyfert, Jonathan H.; VanBaak, Karin

    2016-01-01

    Context: Athletes at different skill levels perform strenuous physical activity at high altitude for a variety of reasons. Multiple team and endurance events are held at high altitude and may place athletes at increased risk for developing acute high altitude illness (AHAI). Training at high altitude has been a routine part of preparation for some of the high level athletes for a long time. There is a general belief that altitude training improves athletic performance for competitive and recreational athletes. Evidence Acquisition: A review of relevant publications between 1980 and 2015 was completed using PubMed and Google Scholar. Study Design: Clinical review. Level of Evidence: Level 3. Results: AHAI is a relatively uncommon and potentially serious condition among travelers to altitudes above 2500 m. The broad term AHAI includes several syndromes such as acute mountain sickness (AMS), high altitude pulmonary edema (HAPE), and high altitude cerebral edema (HACE). Athletes may be at higher risk for developing AHAI due to faster ascent and more vigorous exertion compared with nonathletes. Evidence regarding the effects of altitude training on athletic performance is weak. The natural live high, train low altitude training strategy may provide the best protocol for enhancing endurance performance in elite and subelite athletes. High altitude sports are generally safe for recreational athletes, but they should be aware of their individual risks. Conclusion: Individualized and appropriate acclimatization is an essential component of injury and illness prevention. PMID:26863894

  9. 12 CFR 3.13 - Relation to other actions.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... Banks and Banking COMPTROLLER OF THE CURRENCY, DEPARTMENT OF THE TREASURY MINIMUM CAPITAL RATIOS; ISSUANCE OF DIRECTIVES Establishment of Minimum Capital Ratios for an Individual Bank § 3.13 Relation to... capital ratios for a bank may be established or revised through a written agreement or cease and...

  10. 12 CFR 3.13 - Relation to other actions.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... Banks and Banking COMPTROLLER OF THE CURRENCY, DEPARTMENT OF THE TREASURY MINIMUM CAPITAL RATIOS; ISSUANCE OF DIRECTIVES Establishment of Minimum Capital Ratios for an Individual Bank § 3.13 Relation to... capital ratios for a bank may be established or revised through a written agreement or cease and...

  11. Local fluctuations of ozone from 16 km to 45 km deduced from in situ vertical ozone profile

    NASA Technical Reports Server (NTRS)

    Moreau, G.; Robert, C.

    1994-01-01

    A vertical ozone profile obtained by an in situ ozone sonde from 16 km to 45 km, has allowed to observe local ozone concentration variations. These variations can be observed, thanks to a fast measurement system based on a UV absorption KrF excimer laser beam in a multipass cell. Ozone standard deviation versus altitude calculated from the mean is derived. Ozone variations or fluctuations are correlated with the different dynamic zones of the stratosphere.

  12. High Altitude Plasma Instrument (HAPI) data analysis

    NASA Technical Reports Server (NTRS)

    Burch, J. L.

    1994-01-01

    The objectives of the Dynamics Explorer mission are to investigate the coupling of energy, mass, and momentum among the earth's magnetosphere, ionosphere, and upper atmosphere. At launch, on August 3, 1981, DE-1 was placed into an elliptical polar orbit having an apogee of 23,130 km to allow global auroral imaging and crossings of auroral field lines at altitudes of several thousand kilometers. At the same time DE-2 was placed into a polar orbit, coplanar with that of DE-1 but with a perigee altitude low enough (309 km) for neutral measurements and an apogee altitude of 1012 km. The DE-1 High Altitude Plasma Instrument (HAPI) provided data on low and medium energy electrons and ions from August 13, 1981 until December 1, 1981, when a high-voltage failure occured. Analysis of HAPI data for the time period of this contract has produced new results on the source mechanisms for electron conical distributions, particle acceleration phenomena in auroral acceleration regions, Birkeland currents throughout the nightside auroral regions, the source region for auroral kilometric radiation (AKR), and plasma injection phenomena in the polar cusp.

  13. Acceleration of barium ions near 8000 km above an aurora

    NASA Technical Reports Server (NTRS)

    Stenbaek-Nielsen, H. C.; Hallinan, T. J.; Wescott, E. M.; Foeppl, H.

    1984-01-01

    A barium shaped charge, named Limerick, was released from a rocket launched from Poker Flat Research Range, Alaska, on March 30, 1982, at 1033 UT. The release took place in a small auroral breakup. The jet of ionized barium reached an altitude of 8100 km 14.5 min after release, indicating that there were no parallel electric fields below this altitude. At 8100 km the jet appeared to stop. Analysis shows that the barium at this altitude was effectively removed from the tip. It is concluded that the barium was actually accelerated upward, resulting in a large decrease in the line-of-sight density and hence the optical intensity. The parallel electric potential in the acceleration region must have been greater than 1 kV over an altitude interval of less than 200 km. The acceleration region, although presumably auroral in origin, did not seem to be related to individual auroral structures, but appeared to be a large-scale horizontal structure. The perpendicular electric field below, as deduced from the drift of the barium, was temporally and spatially very uniform and showed no variation related to individual auroral structures passing through.

  14. Observation of radio-wave-induced red hydroxyl emission at low altitude in the ionosphere.

    PubMed

    Kagan, L M; Nicolls, M J; Kelley, M C; Carlson, H C; Belikovich, V V; Bakhmet'eva, N V; Komrakov, G P; Trondsen, T S; Donovan, E

    2005-03-11

    We report the discovery of radio-wave-induced red emission of OH Meinel rotation-vibrational bands at 629.79 nm. These are the first measurements of artificial aurora below 100 km. We believe that the 629.79-nm OH emission was due to radio-wave focusing by sporadic ionization clouds near 80-85 km altitude, thus giving a technique to visualize the low-altitude sporadic ionization and providing insight into ionospheric interactions at these low altitudes.

  15. KM3NeT

    SciTech Connect

    Jong, M. de; Collaboration: KM3NeT Collaboration

    2015-07-15

    KM3NeT is a large research infrastructure, that will consist of a network of deep-sea neutrino telescopes in the Mediterranean Sea. The main objective of KM3NeT is the discovery and subsequent observation of high-energy neutrino sources in the Universe. A further physics perspective is the measurement of the mass hierarchy of neutrinos. A corresponding study, ORCA, is ongoing within KM3NeT. A cost effective technology for (very) large water Cherenkov detectors has been developed based on a new generation of low price 3-inch photo-multiplier tubes. Following the successful deployment and operation of two prototypes, the construction of the KM3NeT research infrastructure has started. The prospects of the different phases of the implementation of KM3NeT are summarised.

  16. Altitude and endurance training.

    PubMed

    Rusko, Heikki K; Tikkanen, Heikki O; Peltonen, Juha E

    2004-10-01

    The benefits of living and training at altitude (HiHi) for an improved altitude performance of athletes are clear, but controlled studies for an improved sea-level performance are controversial. The reasons for not having a positive effect of HiHi include: (1) the acclimatization effect may have been insufficient for elite athletes to stimulate an increase in red cell mass/haemoglobin mass because of too low an altitude (< 2000-2200 m) and/or too short an altitude training period (<3-4 weeks); (2) the training effect at altitude may have been compromised due to insufficient training stimuli for enhancing the function of the neuromuscular and cardiovascular systems; and (3) enhanced stress with possible overtraining symptoms and an increased frequency of infections. Moreover, the effects of hypoxia in the brain may influence both training intensity and physiological responses during training at altitude. Thus, interrupting hypoxic exposure by training in normoxia may be a key factor in avoiding or minimizing the noxious effects that are known to occur in chronic hypoxia. When comparing HiHi and HiLo (living high and training low), it is obvious that both can induce a positive acclimatization effect and increase the oxygen transport capacity of blood, at least in 'responders', if certain prerequisites are met. The minimum dose to attain a haematological acclimatization effect is > 12 h a day for at least 3 weeks at an altitude or simulated altitude of 2100-2500 m. Exposure to hypoxia appears to have some positive transfer effects on subsequent training in normoxia during and after HiLo. The increased oxygen transport capacity of blood allows training at higher intensity during and after HiLo in subsequent normoxia, thereby increasing the potential to improve some neuromuscular and cardiovascular determinants of endurance performance. The effects of hypoxic training and intermittent short-term severe hypoxia at rest are not yet clear and they require further study.

  17. Endurance training at altitude.

    PubMed

    Saunders, Philo U; Pyne, David B; Gore, Christopher J

    2009-01-01

    Since the 1968 Olympic Games when the effects of altitude on endurance performance became evident, moderate altitude training ( approximately 2000 to 3000 m) has become popular to improve competition performance both at altitude and sea level. When endurance athletes are exposed acutely to moderate altitude, a number of physiological responses occur that can comprise performance at altitude; these include increased ventilation, increased heart rate, decreased stroke volume, reduced plasma volume, and lower maximal aerobic power ((.)Vo(2max)) by approximately 15% to 20%. Over a period of several weeks, one primary acclimatization response is an increase in the volume of red blood cells and consequently of (.)Vo(2max). Altitudes > approximately 2000 m for >3 weeks and adequate iron stores are required to elicit these responses. However, the primacy of more red blood cells for superior sea-level performance is not clear-cut since the best endurance athletes in the world, from Ethiopia (approximately 2000 to 3000 m), have only marginally elevated hemoglobin concentrations. The substantial reduction in (.)Vo(2max) of athletes at moderate altitude implies that their training should include adequate short-duration (approximately 1 to 2 min), high-intensity efforts with long recoveries to avoid a reduction in race-specific fitness. At the elite level, athlete performance is not dependent solely on (.)Vo(2max), and the "smallest worthwhile change" in performance for improving race results is as little as 0.5%. Consequently, contemporary statistical approaches that utilize the concept of the smallest worthwhile change are likely to be more appropriate than conventional statistical methods when attempting to understand the potential benefits and mechanisms of altitude training.

  18. Height and altitude distribution of large volcanoes on Venus

    NASA Technical Reports Server (NTRS)

    Keddie, S. T.; Head, J. W.

    1994-01-01

    Magellan data reveal 156 large volcanoes on Venus (greater than 100 km in diameter) which range in height from 300 m to 5.55 km, with an average height of 1.42 km. On the basis of theory it has been predicted that the development of neutral buoyancy zones (NBZ) on Venus and thus the resulting volcanic deposits are strongly influenced by the altitude-controlled variations in surface pressure. The distribution and height of these large volcanoes as a function of altitude was examined to begin to test these predications. Although large volcanoes are relatively uniformly distributed in altitude, there may be a slight paucity of volcanoes at the lowest elevations and a slight surplus at mid-altitudes. In addition, it is observed that the volcanoes at the highest altitudes tend to be the tallest. The observed distributions at low-mid altitudes is consistent with the prediction of NBZ theory. The high altitude distribution and heights, however, emphasize the necessity of considering other factors, such as tectonic setting, edifice age, magma supply, and thermal gradient, in describing the location and development of large volcanoes on Venus.

  19. High altitude plumes at Mars morning terminator

    NASA Astrophysics Data System (ADS)

    Sanchez-Lavega, A.; Garcia Muñoz, A.; Garcia Melendo, E.; Perez-Hoyos, S.; Gomez Forrellad, J. M.; Pellier, C.; Delcroix, M.; Lopez Valverde, M. A.; González Galindo, F.; Jaeschke, W.; Parker, D.; Phillips, J.; Peach, D.

    2015-10-01

    In March and April 2012 two extremely high altitude plumes were observed at the Martian terminator reaching 200 -250 km or more above the surface[1]. They were located at about 195o West longitude and 45o South latitude (at Terra Cimmeria) and extended ˜500 -1,000 km in both North-South and East- West, and lasted for about 10 days. Both plumes exhibited day-to-day variability, and were seen at the morning terminator but not at the evening limb. Another large plume was captured on Hubble Space Telescope images in May 1997 at 99º West longitude and 3º South latitude, but its altitude cannot be pr ecisely determined.Broad-band photometry was performed of both events in the spectral range 255 nm -1052 nm. Based on the observed properties, we discuss different possible scenarios for the mechanism responsible for the formation of these plumes.

  20. 45-km horizontal path optical link demonstration

    NASA Astrophysics Data System (ADS)

    Biswas, Abhijit; Wright, Malcolm W.; Sanii, Babak; Page, Norman A.

    2001-06-01

    Observations made during a mountain-top-to-mountain-top horizontal optical link demonstration are described. The optical link spans a range of 46 Km at an average altitude of 2 Km above sea level. A multibeam beacon comprised of eight laser beams emerging from four multimode fiber coupled lasers (780 nm) is launched through a 0.6 m diameter telescope located at the JPL Table Mountain Facility (TMF) in Wrightwood, California. The multibeam beacon is received at Strawberry Peak located in the San Bernardino Mountains of California. The NASA, JPL developed optical communications demonstrator (OCD) receives the beacon, senses the atmospheric turbulence induced motion and using an upgraded fine steering loop actively points a communications laser beam (852 nm, 400 Mbps on-off key modulated, PN7 pseudo random bit sequence) to TMF. The eight-beam beacon allowed a four-fold reduction in normalized irradiance or scintillation index. This in turn was sufficient to eliminate beacon fades sensed by the OCD and enable performance evaluation of the fine steering loop. The residual tracking error was determined to be +/- 1.1 to +/- 1.7 (mu) rad compared to a model prediction of +/- 3.4 (mu) rad. The best link performance observed showed average bit error rates (BER) of 1E-5 over long durations (30 seconds); however, instantaneous BERs of at least 0.8E-6 over durations of 2 ms were observed. The paper also discusses results pertaining to atmospheric effects, link analysis, and overall performance.

  1. High Altitude Pilgrimage Medicine

    PubMed Central

    2014-01-01

    Abstract Religious pilgrims have been going to high altitude pilgrimages long before trekkers and climbers sojourned in high altitude regions, but the medical literature about high altitude pilgrimage is sparse. Gosainkunda Lake (4300 m) near Kathmandu, Nepal, and Shri Amarnath Yatra (3800 m) in Sri Nagar, Kashmir, India, are the two sites in the Himalayas from where the majority of published reports of high altitude pilgrimage have originated. Almost all travels to high altitude pilgrimages are characterized by very rapid ascents by large congregations, leading to high rates of acute mountain sickness (AMS). In addition, epidemiological studies of pilgrims from Gosainkunda Lake show that some of the important risk factors for AMS in pilgrims are female sex and older age group. Studies based on the Shri Amarnath Yatra pilgrims show that coronary artery disease, complications of diabetes, and peptic ulcer disease are some of the common, important reasons for admission to hospital during the trip. In this review, the studies that have reported these and other relevant findings will be discussed and appropriate suggestions made to improve pilgrims' safety at high altitude. PMID:25330393

  2. CAT altitude avoidance system

    NASA Technical Reports Server (NTRS)

    Gary, B. L. (Inventor)

    1982-01-01

    A method and apparatus are provided for indicating the altitude of the tropopause or of an inversion layer wherein clear air turbulence (CAT) may occur, and the likely severity of any such CAT, includes directing a passive microwave radiometer on the aircraft at different angles with respect to the horizon. The microwave radiation measured at a frequency of about 55 GHz represents the temperature of the air at an ""average'' range of about 3 kilometers, so that the sine of the angle of the radiometer times 3 kilometers equals the approximate altitude of the air whose temperature is measured. A plot of altitude (with respect to the aircraft) versus temperature of the air at that altitude, can indicate when an inversion layer is present and can indicate the altitude of the tropopause or of such an inversion layer. The plot can also indicate the severity of any CAT in an inversion layer. If CAT has been detected in the general area, then the aircraft can be flown at an altitude to avoid the tropopause or inversion layer.

  3. Environmental dynamics at orbital altitudes

    NASA Technical Reports Server (NTRS)

    Karr, G. R.

    1976-01-01

    The influence of real satellite aerodynamics on the determination of upper atmospheric density was investigated. A method of analysis of satellite drag data is presented which includes the effect of satellite lift and the variation in aerodynamic properties around the orbit. The studies indicate that satellite lift may be responsible for the observed orbit precession rather than a super rotation of the upper atmosphere. The influence of simplifying assumptions concerning the aerodynamics of objects in falling sphere analysis were evaluated and an improved method of analysis was developed. Wind tunnel data was used to develop more accurate drag coefficient relationships for studying altitudes between 80 and 120 Km. The improved drag coefficient relationships revealed a considerable error in previous falling sphere drag interpretation. These data were reanalyzed using the more accurate relationships. Theoretical investigations of the drag coefficient in the very low speed ratio region were also conducted.

  4. Geodetic altitude to a triaxial ellipsoidal planet

    NASA Technical Reports Server (NTRS)

    Tang, Charles C. H.

    1988-01-01

    An efficient theoretical model for determining geodetic altitudes with better than millimeter accuracy is proposed, with application to the TOPEX/Poseidon project. The triaxial ellipsoidal subsurface point of a satellite is used as the initial trial solution to achieve an efficient and simple iterative solution. It is found that the second-iteration solution is exact to an accuracy of at least 10 to the -9th km.

  5. Geodetic altitude to a triaxial ellipsoidal planet

    NASA Astrophysics Data System (ADS)

    Tang, Charles C. H.

    1988-09-01

    An efficient theoretical model for determining geodetic altitudes with better than millimeter accuracy is proposed, with application to the TOPEX/Poseidon project. The triaxial ellipsoidal subsurface point of a satellite is used as the initial trial solution to achieve an efficient and simple iterative solution. It is found that the second-iteration solution is exact to an accuracy of at least 10 to the -9th km.

  6. Altitude Registration of Limb-Scattered Radiation

    NASA Technical Reports Server (NTRS)

    Moy, Leslie; Bhartia, Pawan K.; Jaross, Glen; Loughman, Robert; Kramarova, Natalya; Chen, Zhong; Taha, Ghassan; Chen, Grace; Xu, Philippe

    2017-01-01

    One of the largest constraints to the retrieval of accurate ozone profiles from UV backscatter limb sounding sensors is altitude registration. Two methods, the Rayleigh scattering attitude sensing (RSAS) and absolute radiance residual method (ARRM), are able to determine altitude registration to the accuracy necessary for long-term ozone monitoring. The methods compare model calculations of radiances to measured radiances and are independent of onboard tracking devices. RSAS determines absolute altitude errors, but, because the method is susceptible to aerosol interference, it is limited to latitudes and time periods with minimal aerosol contamination. ARRM, a new technique introduced in this paper, can be applied across all seasons and altitudes. However, it is only appropriate for relative altitude error estimates. The application of RSAS to Limb Profiler (LP) measurements from the Ozone Mapping and Profiler Suite (OMPS) on board the Suomi NPP (SNPP) satellite indicates tangent height (TH) errors greater than 1 km with an absolute accuracy of +/-200 m. Results using ARRM indicate a approx. 300 to 400m intra-orbital TH change varying seasonally +/-100 m, likely due to either errors in the spacecraft pointing or in the geopotential height (GPH) data that we use in our analysis. ARRM shows a change of approx. 200m over 5 years with a relative accuracy (a long-term accuracy) of 100m outside the polar regions.

  7. Altitude registration of limb-scattered radiation

    NASA Astrophysics Data System (ADS)

    Moy, Leslie; Bhartia, Pawan K.; Jaross, Glen; Loughman, Robert; Kramarova, Natalya; Chen, Zhong; Taha, Ghassan; Chen, Grace; Xu, Philippe

    2017-01-01

    One of the largest constraints to the retrieval of accurate ozone profiles from UV backscatter limb sounding sensors is altitude registration. Two methods, the Rayleigh scattering attitude sensing (RSAS) and absolute radiance residual method (ARRM), are able to determine altitude registration to the accuracy necessary for long-term ozone monitoring. The methods compare model calculations of radiances to measured radiances and are independent of onboard tracking devices. RSAS determines absolute altitude errors, but, because the method is susceptible to aerosol interference, it is limited to latitudes and time periods with minimal aerosol contamination. ARRM, a new technique introduced in this paper, can be applied across all seasons and altitudes. However, it is only appropriate for relative altitude error estimates. The application of RSAS to Limb Profiler (LP) measurements from the Ozone Mapping and Profiler Suite (OMPS) on board the Suomi NPP (SNPP) satellite indicates tangent height (TH) errors greater than 1 km with an absolute accuracy of ±200 m. Results using ARRM indicate a ˜ 300 to 400 m intra-orbital TH change varying seasonally ±100 m, likely due to either errors in the spacecraft pointing or in the geopotential height (GPH) data that we use in our analysis. ARRM shows a change of ˜ 200 m over ˜ 5 years with a relative accuracy (a long-term accuracy) of ±100 m outside the polar regions.

  8. Neutral winds above 200Km at high latitudes

    NASA Technical Reports Server (NTRS)

    Meriwether, J. W.; Heppner, J. P.; Stolarik, J. D.; Wescott, E. M.

    1972-01-01

    Motion from multiple chemical releases between 200 and 300 km from 15 rockets launched from 4 high latitude locations are analyzed. The observations in the evening and midnight hours at magnetic altitudes or = 65 deg suggest that in these regions ion drag is the dominant force in driving neutral winds between 200 and 300 km. This conclusion is based on both the agreement between ion and neutral drift directions, and the fact that there are distinct changes in the wind associated with (a) the reversal in east-west ion drift at the Harang discontinuity, and (b) the transition from auroral belt, sunward ion drift and polar cap, anti-solar ion drift.

  9. Knob manager (KM) operators guide

    SciTech Connect

    1993-10-08

    KM, Knob Manager, is a tool which enables the user to use the SUNDIALS knob box to adjust the settings of the control system. The followings are some features of KM: dynamic knob assignments with the user friendly interface; user-defined gain for individual knob; graphical displays for operating range and status of each process variable is assigned; backup and restore one or multiple process variable; save current settings to a file and recall the settings from that file in future.

  10. Altitude Modulates Concussion Incidence

    PubMed Central

    Smith, David W.; Myer, Gregory D.; Currie, Dustin W.; Comstock, R. Dawn; Clark, Joseph F.; Bailes, Julian E.

    2013-01-01

    Background: Recent research indicates that the volume and/or pressure of intracranial fluid, a physiology affected by one’s altitude (ie, elevation above sea level), may be associated with the likelihood and/or severity of a concussion. The objective was to employ an epidemiological field investigation to evaluate the relationship between altitude and concussion rate in high school sports. Hypothesis: Because of the physiologies that occur during acclimatization, including a decline in intracranial compliance (a “tighter fit”), increased altitude may be related to a reduction in concussion rates in high school athletes. Study Design: Cohort study; Level of evidence, 3. Methods: Data on concussions and athlete exposures (AEs) between 2005-2006 and 2011-2012 were obtained from a large national sample of high schools (National High School Sports-Related Injury Surveillance System [High School RIO]) and were used to calculate total, competition, and practice concussion rates for aggregated sports and for football only. Results: Altitude of participating schools ranged from 7 to 6903 ft (median, 600 ft), and a total of 5936 concussions occurred in 20,618,915 exposures (2.88 per 10,000 AEs). When concussion rates were dichotomized by altitude using the median, elevated altitude was associated with a reduction in concussion rates overall (rate ratio [RR], 1.31; P < .001), in competition (RR, 1.31; P < .001), and in practice (RR, 1.29; P < .001). Specifically, high school sports played at higher altitude demonstrated a 31% reduction (95% confidence interval [CI], 25%-38%) in the incidence of total reported concussions. Likewise, concussion rates at increased altitude were reduced 30% for overall exposures, 27% for competition exposures, and 28% for practice exposures in football players (P < .001). Conclusion: The results of this epidemiological investigation indicate increased physiological responses to altitude may be associated with a reduction in sports

  11. High Altitude Medical Problems

    PubMed Central

    Hultgren, Herbert N.

    1979-01-01

    Increased travel to high altitude areas by mountaineers and nonclimbing tourists has emphasized the clinical problems associated with rapid ascent. Acute mountain sickness affects most sojourners at elevations above 10,000 feet. Symptoms are usually worse on the second or third day after arrival. Gradual ascent, spending one to three days at an intermediate altitude, and the use of acetazolamide (Diamox) will prevent or ameliorate symptoms in most instances. Serious and potentially fatal problems, such as high altitude pulmonary edema or cerebral edema, occur in approximately 0.5 percent to 1.0 percent of visitors to elevations above 10,000 feet—especially with heavy physical exertion on arrival, such as climbing or skiing. Early recognition, high flow oxygen therapy and prompt descent are crucially important in management. Our knowledge of the causes of these and other high altitude problems, such as retinal hemorrhage, systemic edema and pulmonary hypertension, is still incomplete. Even less is known of the effect of high altitudes on medical conditions common at sea level or on the action of commonly used drugs. ImagesFigure 2. PMID:483805

  12. Medicine at high altitude.

    PubMed

    Wright, Alex D

    2006-01-01

    Medicine at high altitude provides important insights into the acute and chronic effects of hypoxia. Acute mountain sickness (AMS) is a common syndrome occurring after acute ascent to over 2,500 m and is caused by increased capillary permeability. A number of factors have been identified that increase the risk of AMS, in particular exercise. Avoiding rapid ascent, undue exercise and the use of acetazolamide are useful preventative measures but severe symptoms may require oxygen, dexamethasone and descent. Acute mountain sickness is usually self-limiting but may progress into the serious syndromes of pulmonary and cerebral oedema. Acclimatisation and adaptation are important for workers and residents at high altitude and the improvement seen in maximum exercise has been incorporated into some training schedules for endurance athletes. Chronic and subacute high-altitude diseases largely result from polycythemia and pulmonary hypertension.

  13. Description of SHARC: The Strategic High-Altitude Radiance Code.

    DTIC Science & Technology

    1989-08-16

    for Paths from 60 to 300 km altitude in he 2-40 _.m spectral region. It models r-adiation due to NLTE (Non-Local Thermodynamic quilibrium) molecular...2 HIGH-ALTITUDE INFRARED RADIATION CONCEPTS ... ....... 4 2.1 Non-Local Thermodynamic Equilibrium .... ........ 4 2.2 Vibrational Temperature...Non-Local Thermodynamic Equilibrium) populations of higher vibrational states are included in the calculation. The equivalent-width, line-by-line LBL

  14. Low-Altitude Wind Shear Detection With Doppler Radar

    DTIC Science & Technology

    1987-02-01

    feasibility of using the next generation weather radar ( NEXRAD ) sys- tem to detect low-altitude horizontal wind shear near airports is investi- gated. We...requires that NEXRAD radar coverage havd’> lowest scan of 60 m above the surface in the airport area (within 20 km of the,,airport); the strongest...Availability Codes * Avail ~id/or Di’.t Special LIST OF FIGURES Figure 1. FAA requirements of altitude limits of NEXRAD coverage and resolu- tion in

  15. Estimation of high altitude Martian dust parameters

    NASA Astrophysics Data System (ADS)

    Pabari, Jayesh; Bhalodi, Pinali

    2016-07-01

    Dust devils are known to occur near the Martian surface mostly during the mid of Southern hemisphere summer and they play vital role in deciding background dust opacity in the atmosphere. The second source of high altitude Martian dust could be due to the secondary ejecta caused by impacts on Martian Moons, Phobos and Deimos. Also, the surfaces of the Moons are charged positively due to ultraviolet rays from the Sun and negatively due to space plasma currents. Such surface charging may cause fine grains to be levitated, which can easily escape the Moons. It is expected that the escaping dust form dust rings within the orbits of the Moons and therefore also around the Mars. One more possible source of high altitude Martian dust is interplanetary in nature. Due to continuous supply of the dust from various sources and also due to a kind of feedback mechanism existing between the ring or tori and the sources, the dust rings or tori can sustain over a period of time. Recently, very high altitude dust at about 1000 km has been found by MAVEN mission and it is expected that the dust may be concentrated at about 150 to 500 km. However, it is mystery how dust has reached to such high altitudes. Estimation of dust parameters before-hand is necessary to design an instrument for the detection of high altitude Martian dust from a future orbiter. In this work, we have studied the dust supply rate responsible primarily for the formation of dust ring or tori, the life time of dust particles around the Mars, the dust number density as well as the effect of solar radiation pressure and Martian oblateness on dust dynamics. The results presented in this paper may be useful to space scientists for understanding the scenario and designing an orbiter based instrument to measure the dust surrounding the Mars for solving the mystery. The further work is underway.

  16. Space Station Freedom altitude strategy

    NASA Technical Reports Server (NTRS)

    Mcdonald, Brian M.; Teplitz, Scott B.

    1990-01-01

    The Space Station Freedom (SSF) altitude strategy provides guidelines and assumptions to determine an altitude profile for Freedom. The process for determining an altitude profile incorporates several factors such as where the Space Shuttle will rendezvous with the SSF, when reboosts must occur, and what atmospheric conditions exist causing decay. The altitude strategy has an influence on all areas of SSF development and mission planning. The altitude strategy directly affects the micro-gravity environment for experiments, propulsion and control system sizing, and Space Shuttle delivery manifests. Indirectly the altitude strategy influences almost every system and operation within the Space Station Program. Evolution of the SSF altitude strategy has been a very dynamic process over the past few years. Each altitude strategy in turn has emphasized a different consideration. Examples include a constant Space Shuttle rendezvous altitude for mission planning simplicity, or constant micro-gravity levels with its inherent emphasis on payloads, or lifetime altitudes to provide a safety buffer to loss of control conditions. Currently a new altitude strategy is in development. This altitude strategy will emphasize Space Shuttle delivery optimization. Since propellant is counted against Space Shuttle payload-to-orbit capacity, lowering the rendezvous altitude will not always increase the net payload-to-orbit, since more propellant would be required for reboost. This altitude strategy will also consider altitude biases to account for Space Shuttle launch slips and an unexpected worsening of atmospheric conditions. Safety concerns will define a lower operational altitude limit, while radiation levels will define upper altitude constraints. The evolution of past and current SSF altitude strategies and the development of a new altitude strategy which focuses on operational issues as opposed to design are discussed.

  17. Anaerobic performance at altitude.

    PubMed

    Coudert, J

    1992-10-01

    Anaerobic metabolism is usually evaluated by the determination of the anaerobic capacity and the maximal anaerobic mechanical external power (Wmax). Conflicting results are reported on anaerobic capacity evaluated by maximal oxygen deficit and debt, and maximal blood lactate concentration during acute or chronic hypoxia (acclimatized subjects). Data on muscle biopsies (lactate concentration, changes in ATP, phosphocreatine and glycogen stores, glycolytic enzyme activities) and the few studies on lactate flux give in most cases evidence of a non-alteration of the anaerobic capacity for altitudes up to 5,500 m. No differences are observed in Wmax measured at high altitudes up to 5,200 m during intense short-term exercises: (1) jumps on a force platform which is a good indicator of alactic Wmax, and (2) 7-10 s sprints (i.e. force-velocity test) which solicit alactic metabolism but also lactic pathway. For exercises of duration equal or more than 30 s (i.e. Wingate test), there are conflicting results because a lower participation of aerobic metabolism during this test at high altitude can interfere with anaerobic performance. In conclusion, we can admit that anaerobic performances are not altered by high altitudes up to 5,200 m if the length of exposure does not exceed 5 weeks. After this period, muscle mass begins to decrease.

  18. Cardiovascular medicine at high altitude.

    PubMed

    Whayne, Thomas F

    2014-07-01

    Altitude physiology began with Paul Bert in 1878. Chronic mountain sickness (CMS) was defined by Carlos Monge in the 1940s in the Peruvian Andes as consisting of excess polycythemia. Hurtado et al performed studies in the Peruvian Andes in the 1950s to 1960s which defined acclimatization in healthy altitude natives, including polycythemia, moderate pulmonary hypertension, and low systemic blood pressure (BP). Electrocardiographic changes of right ventricular hypertrophy (RVH) were noted. Acclimatization of newcomers to altitude involves hyperventilation stimulated by hypoxia and is usually benign. Acute mountain sickness (AMS) in travelers to altitude is characterized by hypoxia-induced anorexia, dyspnea, headache, insomnia, and nausea. The extremes of AMS are high-altitude cerebral edema and high-altitude pulmonary edema. The susceptible high-altitude resident can lose their tolerance to altitude and develop CMS, also referred to as Monge disease. The CMS includes extreme polycythemia, severe RVH, excess pulmonary hypertension, low systemic BP, arterial oxygen desaturation, and hypoventilation.

  19. Comparison of sprite initiation altitudes between observations and models

    NASA Astrophysics Data System (ADS)

    Gamerota, W. R.; Cummer, S. A.; Li, J.; Stenbaek-Nielsen, H. C.; Haaland, R. K.; McHarg, M. G.

    2011-02-01

    Simultaneous analyses of measured sprite initiation altitudes with predicted initiation altitudes from simulations enable an examination of our understanding of the sprite initiation mechanism and the modeling techniques to simulate this mesospheric electrical phenomenon. In this work, we selected a subset of sprites optically observed from Langmuir Laboratory, NM; locations near Las Vegas, NM, in 2007 and near Portales, NM, in 2008; and a Duke University field station. The sprites were observed by high-speed imaging with time resolutions of at least 1 ms and by low light level imagers. Sprite initiation altitudes were determined by triangulation between Langmuir Laboratory and either Portales or Las Vegas, while star field analysis determined the approximate measured initiation altitudes for Duke observations. These video observations were coordinated with electromagnetic field measurements from Yucca Ridge Field Station and Duke University, respectively. With a 2-D finite difference time domain model, we simulated the lightning-driven electric fields and predict the likely altitude of sprite initiation and compare these findings with the measured initiation altitude of each sprite analyzed. Of 20 discrete sprite events analyzed, both the measured and the simulation-predicted initiation altitudes indicate that long-delayed sprites tend to initiate at lower altitude. The average discrepancy between the measurements and the simulation results is 0.35 km with a standard deviation of 3.6 km. This consistency not only confirms previous results about the relationship between sprite initiation altitude and time delay but also helps to develop confidence in the models to reveal the sprite physics.

  20. High Altitude Cerebral Edema

    DTIC Science & Technology

    1986-03-01

    English literature and Hultgren et al (3.1) described four more cases of HAPE within the next year. In 1960, Chiodi (5) first reported on a Peruvian...altitude and treatment with steroids and diuretics, CSF pressure was 85 mm H 0. In 1960, Chiodi .(5) described a patient 2 suffering with HACE who...Biol. Chem., 157, 297-302, 1945. 5. Chiodi H: "Mal de montana a forma cerebral; possible mecanismo etiopathogenico," An. Fac. Med. Lima., 43, 437

  1. High altitude diving depths.

    PubMed

    Paulev, Poul-Erik; Zubieta-Calleja, Gustavo

    2007-01-01

    In order to make any sea level dive table usable during high altitude diving, a new conversion factor is created. We introduce the standardized equivalent sea depth (SESD), which allows conversion of the actual lake diving depth (ALDD) to an equivalent sea dive depth. SESD is defined as the sea depth in meters or feet for a standardized sea dive, equivalent to a mountain lake dive at any altitude, such that [image omitted] [image omitted] [image omitted] Mountain lakes contain fresh water with a relative density that can be standardized to 1,000 kg m(-3), and sea water can likewise be standardized to a relative density of 1,033 kg m(-3), at the general gravity of 9.80665 m s(-2). The water density ratio (1,000/1,033) refers to the fresh lake water and the standardized sea water densities. Following calculation of the SESD factor, we recommend the use of our simplified diving table or any acceptable sea level dive table with two fundamental guidelines: 1. The classical decompression stages (30, 20, and 10 feet or 9, 6, and 3 m) are corrected to the altitude lake level, dividing the stage depth by the SESD factor. 2. Likewise, the lake ascent rate during diving is equal to the sea ascent rate divided by the SESD factor.

  2. Observations of High-altitude Negative Lightning Leaders

    NASA Astrophysics Data System (ADS)

    Edens, H. E.

    2011-12-01

    On 20 August 2010 a high-speed video recording was made of a bolt-from-the-blue (BFB) lightning flash where the negative leader exited the cloud near 9 km altitude and could be observed in clear air along most of its path to ground. The observation was augmented by data from Langmuir Laboratory's 3-D Lightning Mapping Array (LMA) as well as slow and fast Delta-E and broadband (up to 100 MHz) electric field waveform recordings. The various data sets are correlated in time and time-correlated LMA data is overlaid on the video frames, yielding a spectacular animation of a negative leader as it propagates from 9 km altitude down into air of increasingly higher pressure, contacting ground at 1.5 km altitude. At 9 km altitude, the tip of the negative leader exhibits impulsive emissions of light and retrograde luminosity waves that are seen to travel backward along the channel, away from the leader tip. As the leader propagates down in altitude the light emissions from the leader tip become more continuous in nature and the leader starts branching profusely. The leader velocity, on the order of 10^5 m/s, did not appear to change significantly. At the same storm, 30 minutes before the BFB flash occurred, a photograph was obtained of another negative leader from an intracloud (IC) flash that exited the cloud near the top, propagated several kilometers upward along a slanted path and terminated in clear air at 11 km altitude. The photograph was made with a Nikon D700 digital camera set at high sensitivity. The individual leader steps, which are on the order of 200 m length, are resolved as relatively straight segments of channel between sharp bends. At each bend (or kink) in the channel, clusters of 5 to 8 blue streamer filaments occur that are on the order of 100 m length. Small branches occur at most of the channel bends. One bend in the channel is accompanied by a space stem with blue streamers at both ends. The positive streamer emanating from the space stem and reaching

  3. On the High- and Low- Altitude Limits of the Auroral Electric Field Region

    NASA Technical Reports Server (NTRS)

    Reiff, P. H.; Lu, G.; Burch, J. L.; Winningham, J. D.; Frank, L. A.; Craven, J. D.; Peterson, W. K.; Heelis, R. A.

    1993-01-01

    Using measurements from the High Altitude Plasma Instrument (HAPI) on the Dynamics-Explorer 1 (DE-1) spacecraft and the Low Altitude Plasma Instrument (LAPI) on Dynamics Explorer 2 (DE 2), we investigate both die high altitude and low altitude extents of the auroral acceleration region. To infer the high altitude limit, we searched the HAPI data base for evidence of upward-directed auroral electric fields located above the spacecraft when the HAPI spacecraft is above 9000 km altitude. We find that such acceleration is common when DE-1 flies through die auroral oval at an altitude of 9,000-11,000 km. At altitudes above 11,000 km, the fraction of the orbits with evidence of at least a 1000 V potential drop above the spacecraft falls, becoming essentially zero above an altitude of 15,000 km. Above that altitude, small (100 V) potential drops are frequently observed, but only rarely are approx. 1 kV potentials observed, typically associated with polar cap or 'theta' arcs or westward traveling surges. To investigate the low-altitude limit of the auroral acceleration region, we use conjunctions of DE 1 and DE 2 along auroral field lines and match the upgoing fluxes of ionospheric ions observed by DE 2 with the flux of accelerated upgoing ions observed at DE 1. Calculating the ionospheric scale height from the ion and electron temperatures and assuming that the parallel flow velocity is independent of height above 800 km, we calculate the altitude at which the upwelling ionospheric ions are effectively completely lost to upward acceleration. The initial lowest-altitude acceleration process could be either a perpendicular acceleration or a parallel electric field, but it must be sufficient to give the entire distribution escape energy. We find that in the two cases studied, near the region of peak auroral potential drop the altitude of this acceleration was around 1700 km (near the O/H neutral crossover altitude), but was significantly higher (approx. 2000 km) near the

  4. On the high- and low-altitude limits of the auroral electric field region

    NASA Astrophysics Data System (ADS)

    Reiff, P. H.; Lu, G.; Burch, J. L.; Winningham, J. D.; Frank, L. A.; Craven, J. D.; Peterson, W. K.; Heelis, R. A.

    Using measurements from the High Altitude Plasma Instrument (HAPI) on the Dynamics-Explorer 1 (DE-1) spacecraft and the Low Altitude Plasma Instrument (LAPI) on Dynamics Explorer 2 (DE 2), we investigate both the high altitude and low altitude extents of the auroral acceleration region. To infer the high altitude limit, we searched the HAPI data base for evidence of upward-directed auroral electric fields located above the spacecraft when the HAPI spacecraft is above 9000 km altitude. We find that such acceleration is common when DE-1 flies through the auroral oval at an altitude of 9,000-11,000 km. At altitudes above 11,000 km, the fraction of the orbits with evidence of at least a 1000 V potential drop above the spacecraft falls, becoming essentially zero above an altitude of 15,000 km. Above that altitude, small (100 V) potential drops are frequently observed, but only rarely are -1 kV potentials observed, typically associated with polar cap or "theta" arcs or westward traveling surges. To investigate the low-altitude limit of the auroral acceleration region, we use conjunctions of DE 1 and DE 2 along auroral field lines and match the upgoing fluxes of ionospheric ions observed by DE 2 with the flux of accelerated upgoing ions observed at DE 1. Calculating the ionospheric scale height from the ion and electron temperatures and assuming that the parallel flow velocity is independent of height above 800 km, we calculate the altitude at which the upwelling ionospheric ions are effectively completely lost to upward acceleration. The initial lowest-altitude acceleration process could be either a perpendicular acceleration or a parallel electric field, but it must be sufficient to give the entire distribution escape energy. We find that in the two cases studied, near the region of peak auroral potential drop the altitude of this acceleration was around 1700 km (near the O/H neutral crossover altitude), but was significantly higher (˜2000 km) near the edges of the arc

  5. Altitude and latitude dependence of the equatorial electrojet

    NASA Astrophysics Data System (ADS)

    Singh, A.; Cole, K. D.

    1988-07-01

    A self-consistent and high-resolution dynamo model is used to investigate the effects of day-to-day or seasonal variation of altitude and latitude profiles of the E-plasma density in the equatorial ionosphere on equatorial electrojet (EEJ) structure. Variations in the E-layer peak altitude and amplitude are shown to significantly affect EEJ structure. The results indicate that, for any shape, the EEJ peak appears at or below the E-layer peak altitude. Distinct double peaks occur in the EEJ structure if the E-layer peak is above 105 km or if the gradient is large. The effect of the latitudinal variation of the integrated conductivities of ionospheric field lines upon the amplitude and altitude of the EEJ peak is discussed.

  6. High-Altitude Cassini Radar Imaging of Titan

    NASA Astrophysics Data System (ADS)

    West, R. D.; Stiles, B.; Anderson, Y.; Boehmer, R.; Callahan, P.; Gim, Y.; Hamilton, G.; Hensley, S.; Janssen, M.; Johnson, W. T.; Kelleher, K.; Lorenz, R.; Ostro, S.; Paganelli, F.; Shaffer, S.; Wye, L.; Zebker, H.

    2006-12-01

    The Cassini spacecraft is now about halfway through its primary Tour of the Saturn system. By the time of this meeting, the radar instrument will have collected seven synthetic aperture strips during close flyby's, with 13 more to come. These images have resolutions as fine as 300 m. We present here data acquired using another imaging mode, very high altitude synthetic aperture radar (SAR) imaging, which extends imaging radar coverage and increases coincidental coverage with other Cassini imaging instruments such as VIMS and ISS. We also discuss calibration of SAR images and other radar data from additional engineering observations. Here we examine the performance trade-offs, special processing issues, and science potential of the high- altitude image observations, and the latest results from the calibration data. The high-altitude data collections are distinct from the normal Titan radar images because the range is much larger (around 20,000 km vs 950 km to 5000 km for normal SAR passes). To increase the signal to noise ratio in these circumstances, the radar operates in the lowest bandwidth scatterometer mode while spacecraft pointing control is used to slowly pan the central beam across a small swath. These high altitude images incorporate 150-200 independent looks in order to let us discriminate features that may lie below the noise floor. So far, three high-altitude images have been acquired, during Titan flyby's T12, T13, and T15. In T12 imaging was attempted from 37000 km with an effective resolution around 5 km. In T13 the Huygens Probe landing site was imaged from 11000 km with effective resolution of 1 2 km. In T15 the Tsegehi area was imaged from 20000 km with effective resolution of 2 -3 km. Additional high altitude image segments are also planned during the T19 and T20 Titan flyby's. The calibration observations are conducted independently or coupled with a distant icy satellite observation. They consist of receive-only data in all four bandwidths

  7. Chicxulub High-Altitude Ballistic Ejecta from Central Belize

    NASA Technical Reports Server (NTRS)

    Pope, K. O.; Ocampo, A. C.

    2000-01-01

    Chicxulub ejecta are found in central Belize, 475 km southeast of the impact crater center. These deposits are ballistic ejecta launched along high-altitude trajectories above the atmosphere and deposited as a discontinuous sheet on the terminal Cretaceous land surface.

  8. Satellite altitude determination uncertainties

    NASA Technical Reports Server (NTRS)

    Siry, J. W.

    1972-01-01

    Satellite altitude determination uncertainties will be discussed from the standpoint of the GEOS-C satellite, from the longer range viewpoint afforded by the Geopause concept. Data are focused on methods for short-arc tracking which are essentially geometric in nature. One uses combinations of lasers and collocated cameras. The other method relies only on lasers, using three or more to obtain the position fix. Two typical locales are looked at, the Caribbean area, and a region associated with tracking sites at Goddard, Bermuda and Canada which encompasses a portion of the Gulf Stream in which meanders develop.

  9. Peregrine 100-km Sounding Rocket Project

    NASA Technical Reports Server (NTRS)

    Zilliac, Gregory

    2012-01-01

    The Peregrine Sounding Rocket Program is a joint basic research program of NASA Ames Research Center, NASA Wallops, Stanford University, and the Space Propulsion Group, Inc. (SPG). The goal is to determine the applicability of this technology to a small launch system. The approach is to design, build, and fly a stable, efficient liquefying fuel hybrid rocket vehicle to an altitude of 100 km. The program was kicked off in October of 2006 and has seen considerable progress in the subsequent 18 months. This research group began studying liquifying hybrid rocket fuel technology more than a decade ago. The overall goal of the research was to gain a better understanding of the fundamental physics of the liquid layer entrainment process responsible for the large increase in regression rate observed in these fuels, and to demonstrate the effect of increased regression rate on hybrid rocket motor performance. At the time of this reporting, more than 400 motor tests were conducted with a variety of oxidizers (N2O, GOx, LOx) at ever increasing scales with thrust levels from 5 to over 15,000 pounds (22 N to over 66 kN) in order to move this technology from the laboratory to practical applications. The Peregrine program is the natural next step in this development. A number of small sounding rockets with diameters of 3, 4, and 6 in. (7.6, 10.2, and 15.2 cm) have been flown, but Peregrine at a diameter of 15 in. (38.1 cm) and 14,000-lb (62.3-kN) thrust is by far the largest system ever attempted and will be one of the largest hybrids ever flown. Successful Peregrine flights will set the stage for a wide range of applications of this technology.

  10. DLR HABLEG- High Altitude Balloon Launched Experimental Glider

    NASA Astrophysics Data System (ADS)

    Wlach, S.; Schwarzbauch, M.; Laiacker, M.

    2015-09-01

    The group Flying Robots at the DLR Institute of Robotics and Mechatronics in Oberpfaffenhofen conducts research on solar powered high altitude aircrafts. Due to the high altitude and the almost infinite mission duration, these platforms are also denoted as High Altitude Pseudo-Satellites (HAPS). This paper highlights some aspects of the design, building, integration and testing of a flying experimental platform for high altitudes. This unmanned aircraft, with a wingspan of 3 m and a mass of less than 10 kg, is meant to be launched as a glider from a high altitude balloon in 20 km altitude and shall investigate technologies for future large HAPS platforms. The aerodynamic requirements for high altitude flight included the development of a launch method allowing for a safe transition to horizontal flight from free-fall with low control authority. Due to the harsh environmental conditions in the stratosphere, the integration of electronic components in the airframe is a major effort. For regulatory reasons a reliable and situation dependent flight termination system had to be implemented. In May 2015 a flight campaign was conducted. The mission was a full success demonstrating that stratospheric research flights are feasible with rather small aircrafts.

  11. 45 Km Horizontal Path Optical Link Experiment

    NASA Technical Reports Server (NTRS)

    Biswas, A.; Ceniceros, J.; Novak, M.; Jeganathan, M.; Portillo, A.; Erickson, D.; Depew, J.; Sanii, B.; Lesh, J. R.

    2000-01-01

    Mountain-top to mountain-top optical link experiments have been initiated at JPL, in order to perform a systems level evaluation of optical communications. Progress made so far is reported. ne NASA, JPL developed optical communications demonstrator (OCD) is used to transmit a laser signal from Strawberry Peak (SP), located in the San Bernadino mountains of California. This laser beam is received by a 0.6 m aperture telescope at JPL's Table Mountain Facility (TMF), located in Wrightwood, California. The optical link is bi-directional with the TMF telescope transmitting a continuous 4-wave (cw) 780 run beacon and the OCD sending back a 840 nm, 100 - 500 Mbps pseudo noise (PN) modulated, laser beam. The optical link path is at an average altitude of 2 km above sea level, covers a range of 46.8 km and provides an atmospheric channel equivalent to approx. 4 air masses. Average received power measured at either end fall well within the uncertainties predicted by link analysis. The reduction in normalized intensity variance (sigma(sup 2, sub I)) for the 4-beam beacon, compared to each individual beam, at SP, was from approx. 0.68 to 0.22. With some allowance for intra-beam mis-alignment, this is consistent with incoherent averaging. The sigma(sup2, sub I) measured at TMF approx. 0.43 +/- 0.22 exceeded the expected aperture averaged value of less than 0.1, probably because of beam wander. The focused spot sizes of approx. 162 +/- 6 microns at the TMF Coude and approx. 64 +/- 3 microns on the OCD compare to the predicted size range of 52 - 172 microns and 57 - 93 microns, respectively. This is consistent with 4 - 5 arcsec of atmospheric "seeing". The preliminary evaluation of OCD's fine tracking indicates that the uncompensated tracking error is approx. 3.3 micro rad compared to approx. 1.7 micro rad observed in the laboratory. Fine tracking performance was intermittent, primarily due to beacon fades on the OCD tracking sensor. The best bit error rates observed while

  12. Active Learning in the Atmospheric Science Classroom and beyond through High-Altitude Ballooning

    ERIC Educational Resources Information Center

    Coleman, Jill S. M.; Mitchell, Melissa

    2014-01-01

    This article describes the implementation of high-altitude balloon (HAB) research into a variety of undergraduate atmospheric science classes as a means of increasing active student engagement in real-world, problem-solving events. Because high-altitude balloons are capable of reaching heights of 80,000-100,000 ft (24-30 km), they provide a…

  13. Brain Food at High Altitude.

    PubMed

    Jain, Vishal

    2016-01-01

    Scenic view at high altitude is a pleasure to the eyes, but it has some shortcoming effects as well. High altitude can be divided into different categories, i.e., high altitude (3000-5000 ft), very high altitude (5000-8000 ft), and extreme altitude (above 8000 ft). Much of the population resides at high altitude, and others go there for tourism. Military personnel are also posted there to defend boundaries. As we ascent to high altitude, partial pressure of oxygen reduces, whereas concentration remains the same; this reduces the availability of oxygen to different body parts. This pathophysiological condition is known as hypobaric hypoxia (HH) which leads to oxidative stress and further causes cognitive dysfunction in some cases. Hypoxia causes neurodegeneration in different brain regions; however, the hippocampus is found to be more prone in comparison to other brain regions. As the hippocampus is affected most, therefore, spatial memory is impaired most during such condition. This chapter will give a brief review of the damaging effect of high altitude on cognition and also throw light on possible herbal interventions at high altitude, which can improve cognitive performance as well as provide protection against the deteriorating effect of hypobaric hypoxia at high altitude.

  14. Range Reference Atmosphere, 0.66 Km Altitude, Ascension Island, South Atlantic

    DTIC Science & Technology

    1984-01-01

    Windspeed or modulus of wind vector, a scalar quantity WBAR - The mean value of windspeed in table I X - A general component variable or coordinate axis Y ...A general component variable or coordinate axis - A general component mean value in the [x, y ) coordinate system f - A general component mean value in...the [x, y ] coordinate system a (alpha) - Rotation angle for the [x, y ] coordinate system 6A LO TABLE A. (concluded) 8 (theta) - Wind direction in the

  15. The drag coefficient of cylindrical spacecraft in orbit at altitudes greater than 150 km

    NASA Technical Reports Server (NTRS)

    Herrero, F. A.

    1983-01-01

    The spacecraft of the Geopotential Research Mission (GRM) are cylindrical in form and designed to fly with their longitudinal axes parallel to their direction of flight. The ratio of length to diameter of these spacecraft is roughly equal to 5.0. Other spacecraft previously flown had corresponding ratios roughly equal to 1.0, and therefore the drag produced by impacts on the lateral surfaces of those spacecraft was not as large as it will be on the GRM spacecraft. Since the drag coefficient is essentially the drag force divided by the frontal area in flight, lateral impacts, when taken into account make the GRM drag coefficient significantly larger than the coefficients used before for shorter spacecraft. A simple formula is derived for the drag coefficient of a cylindrical body flying with its long axis along the direction of flight, and it is used to estimate the drag for the GRM. The formula shows that the drag due to lateral surface impacts depends on the ratio of length-to-diameter and on a coefficient C sub LS (lateral surface impact coefficient) which can be determined from previous cylindrical spacecraft flown with the same attitude, or can be obtained from laboratory measurements of momentum accommodation coefficients.

  16. Edwards AFB, California. Range Reference Atmosphere 0-70 KM Altitude

    DTIC Science & Technology

    1983-08-01

    329. 16.000 3.34 4.62 .2165 5.05. 5.01 8.02 4.32 .70 322 . 27.000 -. 62 3.49 .2350 3.12 3.75 5.36 2.73 1.05 305. 28.000 -3.96 2.85 .2846 1.99 3.uj 5.56...8.15 2.62 -. 0465 .64 1.83 8.42 2.48 .23 322 . 22.00.0 -9.39 2.63 -. 1271 .49 1.72 9.57 2.59 .22 316. 23.000 -10.61 2.69 -. 0822 .35 1.67 10.76 2.63...99.999 99.999 999.99 210.12 3.Z2 -. 06 999.99 99.99 999.99 0. 322 . 19.000 99.999 99.999 999.99 212.18 2.44 .05 999.99 99.99 999.91 0. 319. 20.000 99.999

  17. Range Reference Atmosphere 0-30 km Altitude, Eglin AFB, Florida

    DTIC Science & Technology

    1983-08-01

    the entire area under the bivariate normal density function [equation (9)] is unity, upon integration for a given prob- ability ellipse, that given...ellipse contains p-percent of the total area . In the wind statistics, p-percent of the wind vectors fall within the speci- fied probability ellipse... distribucion of each of the six thermodynamic RRA param- * eters is described by its mean value, its standard deviation, and its skewness. Several of these

  18. Range Reference Atmosphere 0-70 KM Altitude, Point Mugu California

    DTIC Science & Technology

    1983-09-01

    downgrading schedules listed in paragraph 4- 207 of DoD 5200. 1-R. Block 16. Distribution Statement of the Report. Insert here the applicable...6.000 .382 .320 1.55 253.10 4.25 -.83 237.07 9.07 -.4Z 449. 525. 7.000 . 207 .182 1.52 245.56 4.32 -.8 230.64 9.44 -.56 431. 524. 8.000 .105 .088...999.99 233.18 3.87 -.06 999.99 99.99 999.99 0. 351 . -88 ti .’. 88 ° •.-’- 7 " " .-/ - .: - . - . : TA LE 111-7. MOISTURE RELATED STATISTICAL PARAMETERS

  19. Taquac, Guam Island. Range Reference Atmosphere 0-30 Km Altitude

    DTIC Science & Technology

    1983-09-01

    CENTERATLANTIC FLEET WEAPONS TRAINING FACILITYNAVAL AIR TEST CENTER D EASTERN SPACE AND MISSILE CENTER "ARMAMENT DIVISION WESTERN SPACE AND MISSILE CENTER AIR...Tables. o.............. 1 C. Data Quality Control Procedures. ....... ............ 2 D . Organization of the Chapters ........ .............. 3 CHAPTER...Computation of Statistical Parameters ...... ..... ................ 8 C. Statistical Wind Models ................. 10 D . Statistical Parameters With

  20. Range Reference Atmosphere 0-70 km Altitude, Cape Canaveral, Florida

    DTIC Science & Technology

    1983-02-01

    B. Scope of the Range Reference Atmosphere and Arrangement of Tables ................. 1 C. Data Quality Control Procedures ............ 2 D ...Coordinate System and Computation of Statistical Parameters ....................... 8 C. Statistical Wind Models ...................... . 10 D ...Levels ............................. 30 C. Computation of Statistical Parameters for Tables II and III ........................... 35 D . Derived Monthly

  1. Range Reference Atmosphere, 0-70 km Altitude, Vandenberg AFB, California,

    DTIC Science & Technology

    1983-04-01

    Because this function is simple, it can easily be graphed manually . How- ever, the generalized plotting technique for electronic computer plotters, as...I SI m .c . . 1 a S T * C,, tci CC .tt~C.) . C. . .. 00 (. 000 . I . 0 0 ,0 .) iiLt C i ) ltO)C.c’)4. - -r- CD 0 0 OSO-n. FM I r- D (P A 4 0-;I , 79 4...232.49 70.000 69.155 .0559 .0970 225.70 98 TABLE IV-4. HYDROSTATIC MODEL ATMOSPHERE APR!IL SIMt ION - IM300 UNDNCKR AF1 Z GEO. Ht. P 0 I Kŕ tci m1 G

  2. Infectious Diseases at High Altitude.

    PubMed

    Basnyat, Buddha; Starling, Jennifer M

    2015-08-01

    Travel to elevations above 2,500 m is an increasingly common activity undertaken by a diverse population of individuals. These may be trekkers, climbers, miners in high-altitude sites in South America, and more recently, soldiers deployed for high-altitude duty in remote areas of the world. What is also being increasingly recognized is the plight of the millions of pilgrims, many with comorbidities, who annually ascend to high-altitude sacred areas. There are also 400 million people who reside permanently in high mountain ranges, which cover one-fifth of the Earth's surface. Many of these high-altitude areas are in developing countries, for example, the Himalayan range in South Asia. Although high-altitude areas may not harbor any specific infectious disease agents, it is important to know about the pathogens encountered in the mountains to be better able to help both the ill sojourner and the native high-altitude dweller. Often the same pathogens prevalent in the surrounding lowlands are found at high altitude, but various factors such as immunomodulation, hypoxia, poor physiological adaptation, and harsh environmental stressors at high altitude may enhance susceptibility to these pathogens. Against this background, various gastrointestinal, respiratory, dermatological, neurological, and other infections encountered at high altitude are discussed.

  3. Altitude release mechanism

    DOEpatents

    Kulhanek, Frank C.

    1977-01-01

    An altitude release mechanism for releasing a radiosonde or other measuring instrument from a balloon carrying it up into the atmosphere includes a bottle partially filled with water, a tube sealed into the bottle having one end submerged in the water in the bottle and the free end extending above the top of the bottle and a strip of water-disintegrable paper held within the free end of the tube linking the balloon to the remainder of the package. As the balloon ascends, the lowered atmospheric air pressure causes the air in the bottle to expand, forcing the water in the bottle up the tubing to wet and disintegrate the paper, releasing the package from the balloon.

  4. 36 CFR 3.13 - What conditions apply to the use of Marine Sanitation Devices (MSD)?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 36 Parks, Forests, and Public Property 1 2014-07-01 2014-07-01 false What conditions apply to the use of Marine Sanitation Devices (MSD)? 3.13 Section 3.13 Parks, Forests, and Public Property NATIONAL... to the use of Marine Sanitation Devices (MSD)? (a) Discharging sewage from any vessel,...

  5. 36 CFR 3.13 - What conditions apply to the use of Marine Sanitation Devices (MSD)?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 36 Parks, Forests, and Public Property 1 2013-07-01 2013-07-01 false What conditions apply to the use of Marine Sanitation Devices (MSD)? 3.13 Section 3.13 Parks, Forests, and Public Property NATIONAL... to the use of Marine Sanitation Devices (MSD)? (a) Discharging sewage from any vessel,...

  6. 36 CFR 3.13 - What conditions apply to the use of Marine Sanitation Devices (MSD)?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 36 Parks, Forests, and Public Property 1 2010-07-01 2010-07-01 false What conditions apply to the use of Marine Sanitation Devices (MSD)? 3.13 Section 3.13 Parks, Forests, and Public Property NATIONAL... to the use of Marine Sanitation Devices (MSD)? (a) Discharging sewage from any vessel,...

  7. 36 CFR 3.13 - What conditions apply to the use of Marine Sanitation Devices (MSD)?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 36 Parks, Forests, and Public Property 1 2012-07-01 2012-07-01 false What conditions apply to the use of Marine Sanitation Devices (MSD)? 3.13 Section 3.13 Parks, Forests, and Public Property NATIONAL... to the use of Marine Sanitation Devices (MSD)? (a) Discharging sewage from any vessel,...

  8. 36 CFR 3.13 - What conditions apply to the use of Marine Sanitation Devices (MSD)?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 36 Parks, Forests, and Public Property 1 2011-07-01 2011-07-01 false What conditions apply to the use of Marine Sanitation Devices (MSD)? 3.13 Section 3.13 Parks, Forests, and Public Property NATIONAL... to the use of Marine Sanitation Devices (MSD)? (a) Discharging sewage from any vessel,...

  9. Microphysical Model of the Venus clouds between 40km and 80km

    NASA Astrophysics Data System (ADS)

    McGouldrick, Kevin

    2013-10-01

    I am continuing to adapt the Community Aerosol and Radiation Model for Atmospheres (CARMA) to successfully simulate the multi-layered clouds of Venus. The present version of the one-dimensional model now includes a simple parameterization of the photochemicial production of sulfuric acid around altitudes of 62km, and its thermochemical destruction below cloud base. Photochemical production in the model is limited by the availability of water vapor and insolation. Upper cloud particles are introduced into the model via binary homogeneous nucleation, while the lower and middle cloud particles are created via activation of involatile cloud condensation nuclei. Growth by condensation and coagulation and coalescence are also treated. Mass loadings and particle sizes compare favorably with the in situ observations by the Pioneer Venus Large Probe Particle Size Spectrometer, and mixing ratios of volatiles compare favorably with remotely sensed observations of water vapor and sulfuric acid vapor. This work was supported by the NASA Planetary Atmospheres Program, grant number NNX11AD79G.

  10. High Altitude Plasma Instrument (HAPI) data analysis. Final report

    SciTech Connect

    Burch, J.L.

    1994-01-01

    The objectives of the Dynamics Explorer mission are to investigate the coupling of energy, mass, and momentum among the earth's magnetosphere, ionosphere, and upper atmosphere. At launch, on August 3, 1981, DE-1 was placed into an elliptical polar orbit having an apogee of 23,130 km to allow global auroral imaging and crossings of auroral field lines at altitudes of several thousand kilometers. At the same time DE-2 was placed into a polar orbit, coplanar with that of DE-1 but with a perigee altitude low enough (309 km) for neutral measurements and an apogee altitude of 1012 km. The DE-1 High Altitude Plasma Instrument (HAPI) provided data on low and medium energy electrons and ions from August 13, 1981 until December 1, 1981, when a high-voltage failure occured. Analysis of HAPI data for the time period of this contract has produced new results on the source mechanisms for electron conical distributions, particle acceleration phenomena in auroral acceleration regions, Birkeland currents throughout the nightside auroral regions, the source region for auroral kilometric radiation (AKR), and plasma injection phenomena in the polar cusp.

  11. [Altitude and the cardiovascular system].

    PubMed

    Richalet, Jean-Paul

    2012-06-01

    A stay at high altitude exposes an individual to various environmental changes (cold, exercise, isolation) but the most stressful for the body is hypoxia. However, the cardiovascular system yields some efficient mechanisms of acclimatization to oxygen lack. Hypoxia activates the adrenergic system and induces a tachycardia that decreases during a prolonged stay at altitude. The desensitization of the adrenergic system leads to a decrease in maximal heart rate and a protection of the myocardium against an energy disequilibrium that could be potentially harmful for the heart. Hypoxia induces a peripheral vasodilation and a pulmonary vasoconstriction, leading to few changes in systemic blood pressure and an increase in pulmonary blood pressure (PHT) that can contribute to a high altitude pulmonary edema. Advice to a cardiac patient who plans to go to high altitude should take into account that all diseases aggravated by increased adrenergic activity or associated with a PHT or a hypoxemia (right-to-left shunt) will be aggravated at high altitude. As altitude increases, a patient with a coronary disease will present an ischemic threshold for a lower power output during an EKG exercise test. The only test allowing predicting the tolerance to high altitude is the hypoxia exercise test realized at 30% of maxVO(2)and at an equivalent altitude of 4,800m.

  12. Altitude measurement for model rocketry

    NASA Astrophysics Data System (ADS)

    Caughey, David A.

    2007-05-01

    The simple, ballistic time-of-flight equation for the maximum altitude of a vertically launched rocket neglects the effects of atmospheric drag. We show that the error introduced by using this equation to estimate the maximum altitude is typically less than 1% because of the effective cancellations of timing errors during the ascent and descent of the rocket.

  13. The GRAD high-altitude balloon flight over Antarctica

    NASA Technical Reports Server (NTRS)

    Eichhorn, G.; Coldwell, R. L.; Dunnam, F. E.; Rester, A. C.; Trombka, J. I.; Starr, R.

    1989-01-01

    The Gamma Ray Advanced Detector (GRAD) consists of a n-type germanium detector inside an active bismuth-germanate Compton and charged particle shield with additional active plastic shielding across the aperture. It will be flown on a high-altitude balloon at 36 km altitude at a latitude of 78 deg S over Antarctica for observations of gamma radiation emitted by the radioactive decay of Co-56 in the supernova SN1987A, for assessment of the performance of bismuth-germanate scintillation material in the radiation environment of near space, for gathering information on the gamma-ray background over Antarctica, and for testing fault-tolerant software.

  14. Effects of altitude on the climbing performance of Monarch butterflies

    NASA Astrophysics Data System (ADS)

    Kang, Chang-Kwon; Sridhar, Madhu; Landrum, David; Aono, Hikaru

    2016-11-01

    Millions of Monarchs annually travel up to 4,000km, the longest migration distance among insects. They fly and overwinter at high altitudes. However, the aerodynamic mechanism enabling the long-range flight of Monarch butterflies is unknown. To study the effects of altitude on the aerodynamic performance of Monarch butterflies, a unique combination of a motion tracking system and a variable pressure chamber that allows controlling the density is used. The condition inside the chamber is systematically varied to simulate high altitude conditions up to 3,000 m. An optical tracking technique is used to characterize the climbing trajectories of freely flying Monarch butterflies. Customized reflective markers are designed to minimize the effects of marker addition. Flapping amplitude and frequency as well as climbing trajectories are measured. Lift acting on the butterfly is also determined by considering the force balance. Results show that the average flight speed and the Reynolds number, in general, decreased with the altitude, whereas, interestingly, the lift coefficient increased with the altitude. More detailed measurements and analyses will be performed in the future to explain the lift enhancement by flying at higher altitudes. This work is partly supported by NSF Grant CBET-1335572 and in part by CK's startup fund provided by UAH.

  15. [Classification of altitude decompression sickness].

    PubMed

    Katuntsev, V P

    2000-01-01

    The article is devoted to the discussion of principles of and approaches to classification of altitude decompression sickness (DCS), one of the most methodically formidable aspects of the problem. Based on his own multiyear experience in altitude DCS investigations and critical review of literature, the author reasons his concept of clinical classification of altitude DCS. The author's concept places emphasis on obligatory consideration of three stages in DCS development: A--pre-disease (the premorbid syndrome), B--uncomplicated (light) and C--complicated (severe) forms. The objective sign of the premorbid state is "silent" gas bubbles in organism detectable by ultrasonic devices. Signs of uncomplicated altitude DCS are musculoarticular pains, local edema and skin itching. Complicated altitude DCS is diagnosed by systemic (respiratory, neurological and cardiovascular) disorders.

  16. El Chichon and 'mystery cloud' aerosols between 30 and 55 km Global observations from the SME visible spectrometer

    NASA Technical Reports Server (NTRS)

    Clancy, R. T.

    1986-01-01

    Visible limb radiances measured by the Solar Mesosphere Explorer (SME) are used to obtain volume scattering ratios for aerosol loading in the 30-55 km altitude range of the stratosphere. Global maps of these ratios are presented for the period January 1982 to August 1984. Significant aerosol scattering from the 'mystery cloud' and El Chichon aerosol layers are found above 30 km. A timescale of approximately 2 months between the appearance of the aerosol at 30.5 km and at 37.5 km is consistent with vertical transport of aerosol or vapor by eddy diffusion above 30 km. An anticorrelation exists between aerosol scattering and stratospheric temperatures. Periods of lower stratospheric temperatures may account for the formation of aerosol between 40 and 55 km altitude.

  17. Neutrons from thunderstorms at low atmospheric altitudes and related doses at aircraft

    NASA Astrophysics Data System (ADS)

    Drozdov, A.; Grigoriev, A.

    2013-02-01

    We conduct a simulation of thunderstorm neutron flashes at the lowest atmospheric altitudes below 10 km. The neutron generation mechanism is based on the nowadays conventional idea of possibility for photonuclear reactions to proceed on the atmospheric components owing to TGF photons. Our modeling includes generation of neutrons from TGF and their further propagation with account of interaction with background nuclei. Using the calculation results we investigate the neutron flux properties with respect to problem of their registration, and predict the radiation environment caused by thunderstorm neutrons on altitudes of civil airflights. It is shown, that good conditions for the neutron flashes observation are provided from the 3 km altitude, and, possibly, the neutrons can be registered at ground level. We also found that thunderstorm-neutron-related effective dose can reach the value of 0.5 mSv in the region close to the TGF source if it is located at an altitude of 10 km.

  18. Extending MGS-TES Temperature Retrievals in the Martian Atmosphere up to 90 Km: Retrieval Approach and Results

    NASA Technical Reports Server (NTRS)

    Feofilov, A. G.; Kutepov, A. A.; Rezac, L.; Smith, M. D.

    2015-01-01

    This paper describes a methodology for performing a temperature retrieval in the Martian atmosphere in the 50-90 km altitude range using spectrally integrated 15 micrometers C02 limb emissions measured by the Thermal Emission Spectrometer (TES), the thermal infrared spectrometer on board the Mars Global Surveyor (MGS). We demonstrate that temperature retrievals from limb observations in the 75-90 km altitude range require accounting for the non-local thermodynamic equilibrium (non-LTE) populations of the C02(v2) vibrational levels. Using the methodology described in the paper, we have retrieved approximately 1200 individual temperature profiles from MGS TES limb observations in the altitude range between 60 and 90 km. 0ur dataset of retrieved temperature profiles is available for download in supplemental materials of this paper. The temperature retrieval uncertainties are mainly caused by radiance noise, and are estimated to be about 2 K at 60 km and below, 4 K at 70 km, 7 K at 80 km, 10 K at 85 km, and 20 K at 90 km. We compare the retrieved profiles to Mars Climate Database temperature profiles and find good qualitative agreement. Quantitatively, our retrieved profiles are in general warmer and demonstrate strong variability with the following values for bias and standard deviations (in brackets) compared to the Martian Year 24 dataset of the Mars Climate Database: 6 (+/-20) K at 60 km, 7.5 (+/-25) K at 65 km, 9 (+/-27) K at 70 km, 9.5 (+/-27) K at 75 km, 10 (+/-28) K at 80 km, 11 (+/-29) K at 85 km, and 11.5 (+/-31) K at 90 km. Possible reasons for the positive temperature bias are discussed. carbon dioxide molecular vibrations

  19. High altitude reconnaissance aircraft

    NASA Technical Reports Server (NTRS)

    Yazdo, Renee Anna; Moller, David

    1990-01-01

    At the equator the ozone layer ranges from 65,000 to 130,000 plus feet, which is beyond the capabilities of the ER-2, NASA's current high altitude reconnaissance aircraft. The Universities Space Research Association, in cooperation with NASA, is sponsoring an undergraduate program which is geared to designing an aircraft that can study the ozone layer at the equator. This aircraft must be able to cruise at 130,000 feet for six hours at Mach 0.7, while carrying 3,000 lbs. of payload. In addition, the aircraft must have a minimum range of 6,000 miles. In consideration of the novel nature of this project, the pilot must be able to take control in the event of unforeseen difficulties. Three aircraft configurations were determined to be the most suitable - a joined-wing, a biplane, and a twin-boom conventional airplane. The performance of each configuration was analyzed to investigate the feasibility of the project.

  20. High Altitude Dermatology.

    PubMed

    Singh, Lt Col G K

    2017-01-01

    Approximately, 140 million people worldwide live permanently at high altitudes (HAs) and approximately another 40 million people travel to HA area (HAA) every year for reasons of occupation, sports or recreation. In India, whole of Ladakh region, part of Northwest Kashmir, Northern part of Sikkim and Tenga valley of Arunachal are considered inhabited areas of HAA. The low quantity of oxygen, high exposure of ultraviolet (UV) light, very low humidity, extreme subzero temperature in winter, high wind velocity, make this region difficult for lowlanders as well as for tourists. Acute mountain sickness, HA pulmonary edema, HA cerebral edema, and thromboembolic conditions are known to occur in HA. However, enough knowledge has not been shared on dermatoses peculiar to this region. Xerosis, UV-related skin disorders (tanning, photomelanosis, acute and chronic sunburn, polymorphic light eruption, chronic actinic dermatitis, actinic cheilitis, etc.), cold injuries (frostbite, chilblains, acrocyanosis, erythrocyanosis, etc.) nail changes (koilonychias), airborne contact dermatitis, insect bite reaction, and skin carcinoma (basal cell carcinomas, squamous cell carcinomas, and also rarely malignant melanoma) are the dermatoses seen in HAAs. Early diagnosis and knowledge of HA dermatoses may prevent serious consequences of disease and improve the quality of life for the visitors as well as for native of the place.

  1. High Altitude Dermatology

    PubMed Central

    Singh, Lt. Col. G K

    2017-01-01

    Approximately, 140 million people worldwide live permanently at high altitudes (HAs) and approximately another 40 million people travel to HA area (HAA) every year for reasons of occupation, sports or recreation. In India, whole of Ladakh region, part of Northwest Kashmir, Northern part of Sikkim and Tenga valley of Arunachal are considered inhabited areas of HAA. The low quantity of oxygen, high exposure of ultraviolet (UV) light, very low humidity, extreme subzero temperature in winter, high wind velocity, make this region difficult for lowlanders as well as for tourists. Acute mountain sickness, HA pulmonary edema, HA cerebral edema, and thromboembolic conditions are known to occur in HA. However, enough knowledge has not been shared on dermatoses peculiar to this region. Xerosis, UV-related skin disorders (tanning, photomelanosis, acute and chronic sunburn, polymorphic light eruption, chronic actinic dermatitis, actinic cheilitis, etc.), cold injuries (frostbite, chilblains, acrocyanosis, erythrocyanosis, etc.) nail changes (koilonychias), airborne contact dermatitis, insect bite reaction, and skin carcinoma (basal cell carcinomas, squamous cell carcinomas, and also rarely malignant melanoma) are the dermatoses seen in HAAs. Early diagnosis and knowledge of HA dermatoses may prevent serious consequences of disease and improve the quality of life for the visitors as well as for native of the place. PMID:28216727

  2. High-altitude aerostats as astronomical platforms

    NASA Astrophysics Data System (ADS)

    Bely, Pierre Y.; Ashford, Robert; Cox, Charles D.

    1995-06-01

    The tropopause, typically at 16 to 18 km altitude at the lower latitudes, dips to 8 km in the polar regions. This makes the cold, dry, and nonturbulent lower stratosphere accessible to tethered aerostats. Tethered aerostats can fly as high as 12 km and are extremely reliable, lasting for many years. In contrast to free-flying balloons, they can stay on station for weeks at a time, and payloads can be safely recovered for maintenance and adjustment and relaunched in a matter of hours. We propose to use such a platform, located first in the Arctic (near Fairbanks, Alaska), and then later in the Antarctic, to operate a new technology 4-meter telescope with diffraction-limited performance in the near-IR. Thanks to the low ambient temperature (200 degrees K), thermal emission from the optics is of the same order as that of the zodiacal light in the 2 to 3 micron band. Since this wavelength interval is the darkest part of the zodiacal light spectrum from optical wavelengths to 100 microns, the combination of high resolution images and a very dark sky make it the spectral region of choice for observing the redshifted light from galaxies and clusters of galaxies at moderate to high redshifts.

  3. Collisional Effects in Simulations of High Altitude Nuclear Explosions

    NASA Astrophysics Data System (ADS)

    Islam, Tanim

    2013-10-01

    The simulation of the later-time (> 1 second) debris dynamics of a high altitude nuclear explosion (HANE) require, at a minimum, an understanding of the interaction of the ionized blast material with the relatively collisional upper ionosphere and lower exosphere (<= 200 km). At these altitudes, the collisional mean free path of ionized atmospheric particles may become smaller than the length scale of the diamagnetic bubble. Here we report on the local dynamics about the debris/air interface for Starfish Prime like, and lower energy, HANEs at altitudes in which collisionality becomes important. We model the debris dynamics with the hybrid plasma simulation code KIM3D, and use a standard Miller-Combi particle pairing algorithm to model particle collisions. We demonstrate new dynamics associated with finite collisionality in mildly collisional HANEs.

  4. Altitude transitions in energy climbs

    NASA Technical Reports Server (NTRS)

    Weston, A. R.; Cliff, E. M.; Kelley, H. J.

    1982-01-01

    The aircraft energy-climb trajectory for configurations with a sharp transonic drag rise is well known to possess two branches in the altitude/Mach-number plane. Transition in altitude between the two branches occurs instantaneously, a 'corner' in the minimum-time solution obtained with the energy-state model. If the initial and final values of altitude do not lie on the energy-climb trajectory, then additional jumps (crude approximations to dives and zooms) are required at the initial and terminal points. With a singular-perturbation approach, a 'boundary-layer' correction is obtained for each altitude jump, the transonic jump being a so-called 'internal' boundary layer, different in character from the initial and terminal layers. The determination of this internal boundary layer is examined and some computational results for an example presented.

  5. Ear - blocked at high altitudes

    MedlinePlus

    ... and blocked ears; Flying and blocked ears; Eustachian tube dysfunction - high altitude ... The eustachian tube is a connection between the middle ear (the space deep to the eardrum) and the back of the ...

  6. A3 Altitude Test Facility

    NASA Technical Reports Server (NTRS)

    Dulreix, Lionel J.

    2009-01-01

    This slide presentation shows drawings, diagrams and photographs of the A3 Altitude Test Facility. It includes a review of the A3 Facility requirements, and drawings of the various sections of the facility including Engine Deck and Superstructure, Test Cell and Thrust Takeout, Structure and Altitude Support Systems, Chemical Steam generators, and the subscale diffuser. There are also pictures of the construction site, and the facility under construction. A Diagram of the A3 Steam system schematic is also shown

  7. Daytime Aspect Camera for Balloon Altitudes

    NASA Technical Reports Server (NTRS)

    Dietz, Kurt L.; Ramsey, Brian D.; Alexander, Cheryl D.; Apple, Jeff A.; Ghosh, Kajal K.; Swift, Wesley R.

    2002-01-01

    We have designed, built, and flight-tested a new star camera for daytime guiding of pointed balloon-borne experiments at altitudes around 40 km. The camera and lens are commercially available, off-the-shelf components, but require a custom-built baffle to reduce stray light, especially near the sunlit limb of the balloon. This new camera, which operates in the 600- to 1000-nm region of the spectrum, successfully provides daytime aspect information of approx. 10 arcsec resolution for two distinct star fields near the galactic plane. The detected scattered-light backgrounds show good agreement with the Air Force MODTRAN models used to design the camera, but the daytime stellar magnitude limit was lower than expected due to longitudinal chromatic aberration in the lens. Replacing the commercial lens with a custom-built lens should allow the system to track stars in any arbitrary area of the sky during the daytime.

  8. A Daytime Aspect Camera for Balloon Altitudes

    NASA Technical Reports Server (NTRS)

    Dietz, Kurt L.; Ramsey, Brian D.; Alexander, Cheryl D.; Apple, Jeff A.; Ghosh, Kajal K.; Swift, Wesley R.; Six, N. Frank (Technical Monitor)

    2001-01-01

    We have designed, built, and flight-tested a new star camera for daytime guiding of pointed balloon-borne experiments at altitudes around 40km. The camera and lens are commercially available, off-the-shelf components, but require a custom-built baffle to reduce stray light, especially near the sunlit limb of the balloon. This new camera, which operates in the 600-1000 nm region of the spectrum, successfully provided daytime aspect information of approximately 10 arcsecond resolution for two distinct star fields near the galactic plane. The detected scattered-light backgrounds show good agreement with the Air Force MODTRAN models, but the daytime stellar magnitude limit was lower than expected due to dispersion of red light by the lens. Replacing the commercial lens with a custom-built lens should allow the system to track stars in any arbitrary area of the sky during the daytime.

  9. The Gravity Field of Mercury After the Messenger Low-Altitude Campaign

    NASA Technical Reports Server (NTRS)

    Mazarico, Erwan; Genova, Antonio; Goossens, Sander; Lemoine, Frank G.; Smith, David E.; Zuber, Maria T.; Neumann, Gary A.; Solomon, Sean C.

    2015-01-01

    The final year of the MESSENGER mission was designed to take advantage of the remaining propellant onboard to provide a series of lowaltitude observation campaigns and acquire novel scientific data about the innermost planet. The lower periapsis altitude greatly enhances the sensitivity to the short-wavelength gravity field, but only when the spacecraft is in view of Earth. After more than 3 years in orbit around Mercury, the MESSENGER spacecraft was tracked for the first time below 200-km altitude on 5 May 2014 by the NASA Deep Space Network (DSN). Between August and October, periapsis passages down to 25-km altitude were routinely tracked. These periods considerably improved the quality of the data coverage. Before the end of its mission, MESSENGER will fly at very low altitudes for extended periods of time. Given the orbital geometry, however the periapses will not be visible from Earth and so no new tracking data will be available for altitudes lower than 75 km. Nevertheless, the continuous tracking of MESSENGER in the northern hemisphere will help improve the uniformity of the spatial coverage at altitudes lower than 150 km, which will further improve the overall quality of the Mercury gravity field.

  10. Pure Rotational Raman Lidar for Temperature Measurements from 5-40 Km Over Wuhan, China

    NASA Astrophysics Data System (ADS)

    Li, Yajuan; Song, Shalei; Yang, Yong; Li, Faquan; Cheng, Xuewu; Chen, Zhenwei; Liu, Linmei; McCormick, M. Patrick; Gong, Shunsheng

    2016-06-01

    In this paper a pure rotational Raman lidar (PRR) was established for the atmospheric temperature measurements from 5 km to 40 km over Wuhan, China (30.5°N, 114.5°E). To extract the expected PRR signals and simultaneously suppress the elastically backscattered light, a high-spectral resolution polychromator for light splitting and filtering was designed. Observational results revealed that the temperature difference measured by PRR lidar and the local radiosonde below 30 km was less than 3.0 K. The good agreement validated the reliability of the PRR lidar. With the 1-h integration and 150-m spatial resolution, the statistical temperature error for PRR lidar increases from 0.4 K at 10 km up to 4 K at altitudes of about 30 km. In addition, the whole night temperature profiles were obtained for study of the long-term observation of atmospheric fluctuations.

  11. Stratospheric microbiology at 20 km over the Pacific Ocean

    USGS Publications Warehouse

    Smith, David J.; Griffin, Dale W.; Schuerger, Andrew C.

    2010-01-01

    An aerobiology sampling flight at 20 km was conducted on 28 April 2008 over the Pacific Ocean (36.5° N, 118–149° W), a period of time that coincided with the movement of Asian dust across the ocean. The aim of this study was to confirm the presence of viable bacteria and fungi within a transoceanic, atmospheric bridge and to improve the resolution of flight hardware processing techniques. Isolates of the microbial strains recovered were analyzed with ribosomal ribonucleic acid (rRNA) sequencing to identify bacterial species Bacillus sp., Bacillus subtilis, Bacillus endophyticus, and the fungal genus Penicillium. Satellite imagery and ground-based radiosonde observations were used to measure dust movement and characterize the high-altitude environment at the time of collection. Considering the atmospheric residency time (7–10 days), the extreme temperature regime of the environment (-75°C), and the absence of a mechanism that could sustain particulates at high altitude, it is unlikely that our samples indicate a permanent, stratospheric ecosystem. However, the presence of viable fungi and bacteria in transoceanic stratosphere remains relevant to understanding the distribution and extent of microbial life on Earth.

  12. Spectral analysis of the multiple-altitude anomalous geomagnetic field

    NASA Astrophysics Data System (ADS)

    Tsvetkov, Yu. P.; Ivanov, V. V.; Petrov, V. G.; Filippov, S. V.; Brekhov, O. M.

    2016-11-01

    The spectra of the anomalous geomagnetic field measured at ground and balloon (30 km) altitudes were analyzed. The ground-based data were adapted from a map of the anomalous magnetic field of the Earth. A balloon surveys was carried out by the authors. It has been shown that the ground and balloon spectra of the anomalous magnetic field of the Earth substantially differ. Suppositions explaining the differences in the obtained spectra have been suggested.

  13. Altitude is positively correlated to race time during the marathon.

    PubMed

    Lara, Beatriz; Salinero, Juan José; Del Coso, Juan

    2014-04-01

    Completing a marathon (42.2 km) is one of the more challenging sports activities. Besides the distance, the ambient conditions of the race (altitude, temperature, etc) can increase the physiological demands of the event. The purpose of this study was to investigate the relation between the altitude of the city in which the marathon is held and the marathon race time. For this purpose, we sought the race times of 16 popular marathons performed at different altitudes above sea level (range from ≈0 to 2800 meters above sea level). In these competitions, we analyzed the race times of the female and male runners who finished from 21(st) to 100(th) position. We excluded the top 20 male and female finishers from the analysis because elite athletes usually compete in marathons held at low altitudes above sea level. Ambient temperature, the positive cumulative elevation gain, and the number of participants were used as control variables. Finishing time in the marathon was positively correlated with the altitude of the competition for both male (r=0.78; p<0.05) and female participants (r=0.73; p<0.05). On average, each increase of 1000 meters above sea level augmented marathon race time by 10.8±0.6% in men and 12.3±0.7% in women. Compared to race times in the Rotterdam marathon (held at 0 meters above sea level), the time taken to complete the marathon was significantly higher in competitions held at an altitude of over 700 meters. In conclusion, the time taken to complete a marathon strongly depends on the altitude of the city in which the marathon is held. Selecting marathon competitions close to 0 m above sea level is a good strategy to maximize marathon performance.

  14. Certification and safety aspects relating to the transport of passengers on high altitude balloons in Europe

    NASA Astrophysics Data System (ADS)

    Schoenmaker, Annelie

    2014-07-01

    High-altitude balloons typically fly between 25 and 50 km in altitude, which, while below the Karman line of 100 km, is yet far above the altitudes typically flown by aircraft. For example, the highest-flying commercial aircraft - the Concorde - had a maximum cruising altitude of only 18 km. zero2infinity, a Spanish company, is currently developing a pressurized pod named “bloon” which will be capable of lifting six people, including two pilot crew members and four paying passengers, to an altitude of 36 km through the use of high-altitude balloons. The boundary between Airspace and Outer Space has never been legally defined, mostly because of the lack of activities taking place between the altitude where airplanes fly and the lowest orbiting spacecraft. High-altitude balloons do fly at these in-between altitudes and the prospect of commercializing access to these parts of the stratosphere poses some questions in a new light. Given the relatively low altitude at which they fly, it may well be that these types of balloons would be considered to operate exclusively within air space. However, given the technology involved in crewed high altitude balloon flights, which is more similar to spacecraft engineering than to traditional hot-air or gas ballooning, it is necessary to evaluate the various legal regimes, codes, and regulations that would apply to such flights, especially regarding licenses and liabilities. For high altitude balloon flights commencing in Europe, the European Aviation Safety Agency (EASA) would very likely be the competent certification or licensing agency for these flights, although there would likely be input from various national aviation authorities as well. However, because the European Commission (EC) has not yet issued regulations regarding commercial spaceflight, particularly the use of high altitude balloons, new rules and regulations governing such flights may still need to be drafted and promulgated. With the development of

  15. Asteroid airburst altitude vs. strength

    NASA Astrophysics Data System (ADS)

    Robertson, Darrel; Wheeler, Lorien; Mathias, Donovan

    2016-10-01

    Small NEO asteroids (<Ø140m) may not be a threat on a national or global level but can still cause a significant amount of local damage as demonstrated by the Chelyabinsk event where there was over $33 million worth of damage (1 billion roubles) and 1500 were injured, mostly due to broken glass. The ground damage from a small asteroid depends strongly on the altitude at which they "burst" where most of the energy is deposited in the atmosphere. The ability to accurately predict ground damage is useful in determining appropriate evacuation or shelter plans and emergency management.Strong asteroids, such as a monolithic boulder, fail and create peak energy deposition close to the altitude at which ram dynamic pressure exceeds the material cohesive strength. Weaker asteroids, such as a rubble pile, structurally fail at higher altitude, but it requires the increased aerodynamic pressure at lower altitude to disrupt and disperse the rubble. Consequently the resulting airbursts have a peak energy deposition at similar altitudes.In this study hydrocode simulations of the entry and break-up of small asteroids were performed to examine the effect of strength, size, composition, entry angle, and speed on the resulting airburst. This presentation will show movies of the simulations, the results of peak burst height, and the comparison to semi-analytical models.

  16. The effect of ski training at altitude and racing on pituitary, adrenal and testicular function in men.

    PubMed

    Vasankari, T J; Rusko, H; Kujala, U M; Huhtaniemi, I T

    1993-01-01

    The effect of similar prolonged exercise on hormonal changes was studied at sea level and at moderate altitude. Four cross-country skiers participated in a 30-km race and five biathlonists in a 20-km race at sea level in Finland and during altitude training and racing at 1650 m in Les Saisies, France. Venous blood samples were taken at both altitudes before the race between 0800 and 0900 hours and 25-35 min after the race. Resting blood samples were also taken before and after the altitude training and the period of racing. Serum testosterone concentration was higher before the race at altitude than at sea level (19%, P < 0.02), and 30 min after the race growth hormone (GH) concentration was higher at sea level than at moderate altitude (P < 0.002). There were not significant differences in serum luteinising hormone between the altitudes. Serum cortisol concentration was higher after the altitude training and the period of racing than before (P < 0.02) but no difference was observed in testosterone. We concluded, that since the profiles of the anabolic-catabolic hormone concentrations measured are indicators of the performance level of athletes, our data indicated that to follow them during altitude training could be beneficial in optimizing training programme for individual athletes. We also concluded, that the lower GH concentration after racing at moderate altitude may have been a consequence of decreased racing speed and/or increased physical performance.

  17. Remote detection of the maximum altitude of equatorial ionospheric plasma bubbles

    NASA Technical Reports Server (NTRS)

    Benson, R. F.

    1981-01-01

    Nearly 200 post-sunset low-altitude passes of the Alouette 2 and ISIS 1 satellites near the dip equator are studied in order to find the maximum ionospheric plasma bubble altitudes, which are determined by calculating the apex altitude of the magnetic field line passing through the satellite when it is immersed in a bubble. The calculations are made only upon the observation of conjugate hemisphere ionospheric echoes, which result from ducted HF sounder signals that are guided along field-aligned irregularities within the plasma depletion. The maximum bubble altitudes corresponding to the three longitude sectors centered on zero deg, 75 deg W, and 105 deg E, are found to often exceed 1000 km, but seldom 3000 km. The electron density depletions within these field-aligned bubbles, as measured at the point of satellite encounter with the topside ionosphere, are generally less than a factor of two but may exceed a factor of ten.

  18. Operable Unit 3-13, Group 7, SFE-20 Hot Waste Tank System Remedial Action Report

    SciTech Connect

    Lee Davison

    2009-06-30

    This Remedial Action Report summarizes activities undertaken to remediate the Operable Unit 3-13, Group 7, SFE-20 Hot Waste Tank System at the Idaho Nuclear Technology and Engineering Center at the Idaho National Laboratory Site. The site addressed in this report was defined in the Operable Unit 3-13 Record of Decision and subsequent implementing documents. This report concludes that remediation requirements and cleanup goals established for the site have been accomplished and is hereafter considered a No Further Action site.

  19. Operable Unit 3-13, Group 7, SFE-20 Hot Waste Tank System Remedial Action Request

    SciTech Connect

    L. Davison

    2009-06-30

    This Remedial Action Report summarizes activities undertaken to remediate the Operable Unit 3-13, Group 7, SFE-20 Hot Waste Tank System at the Idaho Nuclear Technology and Engineering Center at the Idaho National Laboratory Site. The site addressed in this report was defined in the Operable Unit 3-13 Record of Decision and subsequent implementing documents. This report concludes that remediation requirements and cleanup goals established for the site have been accomplished and is hereafter considered a No Further Action site.

  20. Operable Unit 3-13, Group 3, Other Surface Soils (Phase II) Field Sampling Plan

    SciTech Connect

    G. L. Schwendiman

    2006-07-27

    This Field Sampling Plan describes the Operable Unit 3-13, Group 3, Other Surface Soils, Phase II remediation field sampling activities to be performed at the Idaho Nuclear Technology and Engineering Center located within the Idaho National Laboratory Site. Sampling activities described in this plan support characterization sampling of new sites, real-time soil spectroscopy during excavation, and confirmation sampling that verifies that the remedial action objectives and remediation goals presented in the Final Record of Decision for Idaho Nuclear Technology and Engineering Center, Operable Unit 3-13 have been met.

  1. Solar collector with altitude tracking

    DOEpatents

    Barak, Amitzur Z.

    1977-01-01

    A device is provided for turning a solar collector about an east-west horizontal axis so that the collector is tilted toward the sun as the EWV altitude of the sun varies each day. It includes one or more heat responsive elements and a shading means aligned so that within a range of EWV altitudes of the sun during daylight hours the shading means shades the element or elements while during the rest of the daylight hours the elements or elements are heated by the sun to assume heated, stable states. Mechanical linkage between the collector and the element is responsive to the states of the element or elements to tilt the collector in accordance with variations in the EWV altitude of the sun.

  2. Lightweight Liquid Helium Dewar for High-Altitude Balloon Payloads

    NASA Technical Reports Server (NTRS)

    Kogut, Alan; James, Bryan; Fixsen, Dale

    2013-01-01

    Astrophysical observations at millimeter wavelengths require large (2-to-5- meter diameter) telescopes carried to altitudes above 35 km by scientific research balloons. The scientific performance is greatly enhanced if the telescope is cooled to temperatures below 10 K with no emissive windows between the telescope and the sky. Standard liquid helium bucket dewars can contain a suitable telescope for telescope diameter less than two meters. However, the mass of a dewar large enough to hold a 3-to-5-meter diameter telescope would exceed the balloon lift capacity. The solution is to separate the functions of cryogen storage and in-flight thermal isolation, utilizing the unique physical conditions at balloon altitudes. Conventional dewars are launched cold: the vacuum walls necessary for thermal isolation must also withstand the pressure gradient at sea level and are correspondingly thick and heavy. The pressure at 40 km is less than 0.3% of sea level: a dewar designed for use only at 40 km can use ultra thin walls to achieve significant reductions in mass. This innovation concerns new construction and operational techniques to produce a lightweight liquid helium bucket dewar. The dewar is intended for use on high-altitude balloon payloads. The mass is low enough to allow a large (3-to-5-meter) diameter dewar to fly at altitudes above 35 km on conventional scientific research balloons without exceeding the lift capability of the balloon. The lightweight dewar has thin (250- micron) stainless steel walls. The walls are too thin to support the pressure gradient at sea level: the dewar launches warm with the vacuum space vented continuously during ascent to eliminate any pressure gradient across the walls. A commercial 500-liter storage dewar maintains a reservoir of liquid helium within a minimal (hence low mass) volume. Once a 40-km altitude is reached, the valve venting the vacuum space of the bucket dewar is closed to seal the vacuum space. A vacuum pump then

  3. The altitude of type 3 auroral irregularities - Radar interferometer observations and implications

    NASA Astrophysics Data System (ADS)

    Sahr, J. D.; Farley, D. T.; Swartz, W. E.; Providakes, J. F.

    1991-10-01

    Altitude measurements are presented of type 3 auroral irregularities, acquired in northern Scandinavia in March 1989 during the second E Region Rocket Radar Instability Study campaign, that provide conclusive arguments against the electrostatic ion cyclotron instability theory. Interferometric analyses of coherent radar observations with a portable radar interferometer show that type 3 events occur at typical electrojet altitudes (100-120 km), at which the ion collision frequency is greater than the ion gyrofrequency, and no cyclotron motion is possible.

  4. 7 CFR 3.13 - Contracting with private collection contractors and with entities that locate and recover...

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 1 2010-01-01 2010-01-01 false Contracting with private collection contractors and with entities that locate and recover unclaimed assets. 3.13 Section 3.13 Agriculture Office of the... Claims § 3.13 Contracting with private collection contractors and with entities that locate and...

  5. 7 CFR 3.13 - Contracting with private collection contractors and with entities that locate and recover...

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 1 2011-01-01 2011-01-01 false Contracting with private collection contractors and with entities that locate and recover unclaimed assets. 3.13 Section 3.13 Agriculture Office of the... Claims § 3.13 Contracting with private collection contractors and with entities that locate and...

  6. 16 CFR 3.13 - Adjudicative hearing on issues arising in rulemaking proceedings under the Fair Packaging and...

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 16 Commercial Practices 1 2010-01-01 2010-01-01 false Adjudicative hearing on issues arising in rulemaking proceedings under the Fair Packaging and Labeling Act. 3.13 Section 3.13 Commercial Practices... PROCEEDINGS Pleadings § 3.13 Adjudicative hearing on issues arising in rulemaking proceedings under the...

  7. CO2 LIDAR measurements over a 20-km slant path

    NASA Astrophysics Data System (ADS)

    Senft, Daniel C.; Fox, Marsha J.; Gonglewski, John D.; Dowling, James A.; Highland, Ronald G.; Shilko, Michael L.

    1997-01-01

    The Air Force Phillips Laboratory conducted a series of measurements in February, May and August 1995 at the Air Force Maui Optical Station (AMOS) facility on Maui, Hawaii, to determine system requirements for an airborne long path CO(subscript 2) DIAL system. The lidar incorporates a cavity-matched mode-locked 3-J laser with the 60 cm diameter AMOS Beam Director Telescope. The one-way beam propagation path length was 21.3 km, originating at the AMOS facility on Haleakala at an altitude of 3.050 km ASL, and terminating at a target site near sea level. Both heterodyne and direct detection techniques are compared with respect to radiometric performance and signal statistics. Minimum detectable absorption levels for DIAL systems using both detection techniques and a variety of targets are estimated from long- range measurements with controlled absorbers. The signal correlation as a function of interpulse temporal separation was determined for long-range direct detection measurements. Radiometric models including system optical characteristics, beam propagation considerations, target reflectivity characteristics,a nd atmospheric effects have been developed and validated experimentally. A new receiver system is currently being fabricated and the laser transmitter is being upgraded for pulse-to-pulse wavelength agility, prior to incorporation into a C-135E airborne platform for future flight experiments.

  8. Source altitude for experiments to simulate space-to-earth laser propagation.

    NASA Technical Reports Server (NTRS)

    Minott, P. O.

    1973-01-01

    The bias in scintillation measurements caused by the proximity of a spherical-wave source to the turbulence region of the atmosphere is predicted, and the laser-source altitude required for meaningful experiments simulating space-to-earth laser propagation is estimated. It is concluded that the source should be located at two or more times the maximum altitude of the tropopause to ensure that all measurements are not biased by more than 25%. Thus the vehicle used for experiments of this type should be capable of reaching a minimum altitude of 32 km.

  9. Mercury: Evidence for anorthosite and basalt from mid-infrared (7.3-13.5 micrometers) spectroscopy

    NASA Technical Reports Server (NTRS)

    Sprague, A. L.; Kozlowski, R. W. H.; Witteborn, F. C.; Cruikshank, D. P.; Wooden, D. H.

    1994-01-01

    Spectroscopic observations (7.3-13.5 micrometers) of three locations on the surface of Mercury are reported. The observed spectral radiance emanated from equatorial and low altitude regions between 12 and 32 deg mercurian longitude on 8 December 1990, from the longitudinal region 22-44 deg on 10 December 1990, and from the longitudinal region 110-130 deg on 12 July 1992; all locations are primarily intercrater plains. Spectra indicate compositional differences among these three locations. The emissivity maximum, or Christiansen emission peak, occurs at 8.1 micrometers in the 8 December 1990 spectra, but at shorter wavelengths in the data of 10 December 1990 and 12 July 1992. Emission peaks near 8 micrometers indicate rocks of intermediate or mafic composition. Spectra from 22 to 44 deg longitude resemble spectra of terrestrial basalt and diorite with SiO2 content between 49 and 55%. The Christiansen feature in spectra from near 110-130 deg longitude strongly suggests the presence of plagioclase, in particular labradorite, while the overall spectrum resembles anorthosite. The spectra from all three locations on Mercury show distinct and recognizable features, the principal Christiansen emission peak being the most prominent, but they also contain features that we have not yet identified. The general indication from the spectra is that Mercury's surface consists of minerals more depleted in oxidized iron than those on the Moon. We also explore the theoretical and observational complexities of ground-based mid-infrared spectroscopy of airless bodies in general and Mercury in particular. A spectroscopic study of quartzite in both reflectance and emittance illustrates the practical, spectral validity of Kirchhoff's law.

  10. 9 CFR 3.13 - Consignments to carriers and intermediate handlers.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ..., and Transportation of Dogs and Cats 1 Transportation Standards § 3.13 Consignments to carriers and intermediate handlers. (a) Carriers and intermediate handlers must not accept a dog or cat for transport in... a dog or cat to extend this time by up to 2 hours. (b) Carriers and intermediate handlers must...

  11. 9 CFR 3.13 - Consignments to carriers and intermediate handlers.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ..., and Transportation of Dogs and Cats 1 Transportation Standards § 3.13 Consignments to carriers and intermediate handlers. (a) Carriers and intermediate handlers must not accept a dog or cat for transport in... a dog or cat to extend this time by up to 2 hours. (b) Carriers and intermediate handlers must...

  12. 9 CFR 3.13 - Consignments to carriers and intermediate handlers.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ..., and Transportation of Dogs and Cats 1 Transportation Standards § 3.13 Consignments to carriers and intermediate handlers. (a) Carriers and intermediate handlers must not accept a dog or cat for transport in... a dog or cat to extend this time by up to 2 hours. (b) Carriers and intermediate handlers must...

  13. 9 CFR 3.13 - Consignments to carriers and intermediate handlers.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ..., and Transportation of Dogs and Cats 1 Transportation Standards § 3.13 Consignments to carriers and intermediate handlers. (a) Carriers and intermediate handlers must not accept a dog or cat for transport in... a dog or cat to extend this time by up to 2 hours. (b) Carriers and intermediate handlers must...

  14. 9 CFR 3.13 - Consignments to carriers and intermediate handlers.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ..., and Transportation of Dogs and Cats 1 Transportation Standards § 3.13 Consignments to carriers and intermediate handlers. (a) Carriers and intermediate handlers must not accept a dog or cat for transport in... a dog or cat to extend this time by up to 2 hours. (b) Carriers and intermediate handlers must...

  15. Production altitude and time delays of the terrestrial gamma flashes: Revisiting the Burst and Transient Source Experiment spectra

    NASA Astrophysics Data System (ADS)

    Østgaard, N.; Gjesteland, T.; Stadsnes, J.; Connell, P. H.; Carlson, B.

    2008-02-01

    On the basis of the RHESSI results it has been suggested that terrestrial gamma flashes (TGFs) are produced at very low altitudes. On the other hand some of the Burst and Transient Source Experiment (BATSE) spectra show unabsorbed fluxes of X rays in the 25-50 keV energy range, indicating a higher production altitude. To investigate this, we have developed a Monte Carlo code for X-ray propagation through the atmosphere. The most important features seen in the modeled spectra are (1) a low-energy cutoff which moves to lower energies as TGFs are produced at higher altitudes, (2) a high-energy cutoff which moves to lower energies as TGFs are observed at larger zenith angles, and (3) time delays are observed for TGFs produced at <=20 km (and some at 30 km) altitude when observed at larger zenith angle than the half-angle defining the initial isotropic X-ray beam. This is a pure Compton effect. The model results and an optimization procedure are used to estimate production altitudes of the BATSE TGFs. The main findings are (1) half or more of the BATSE TGFs are produced at low altitudes, <=20 km, (2) a significant portion of the BATSE TGFs are produced at higher altitudes, 30 km to 40 km, (3) for the TGFs produced at <=20 km (and some at 30 km) altitudes the dispersion signatures can be explained as a pure Compton effect, and (4) the softening of the BATSE spectra for increasing zenith angles and the time dispersions both indicate that the initial TGF distribution is beamed.

  16. Altitude preexposure recommendations for inducing acclimatization.

    PubMed

    Muza, Stephen R; Beidleman, Beth A; Fulco, Charles S

    2010-01-01

    For many low-altitude (<1500 m) residents, their travel itineraries may cause them to ascend rapidly to high (>2400 m) altitudes without having the time to develop an adequate degree of altitude acclimatization. Prior to departing on these trips, low-altitude residents can induce some degree of altitude acclimatization by ascending to moderate (>1500 m) or high altitudes during either continuous or intermittent altitude preexposures. Generally, the degree of altitude acclimatization developed is proportional to the altitude attained and the duration of exposure. The available evidence suggests that continuous residence at 2200 m or higher for 1 to 2 days or daily 1.5- to 4-h exposures to >4000 m induce ventilatory acclimatization. Six days at 2200 m substantially decreases acute mountain sickness (AMS) and improves work performance after rapid ascent to 4300 m. There is evidence that 5 or more days above 3000 m within the last 2 months will significantly decrease AMS during a subsequent rapid ascent to 4500 m. Exercise training during the altitude preexposures may augment improvement in physical performance. The persistence of altitude acclimatization after return to low altitude appears to be proportional to the degree of acclimatization developed. The subsequent ascent to high altitude should be scheduled as soon as possible after the last altitude preexposure.

  17. Simplified Analytical Solution for Martian OH*-layer Altitude

    NASA Astrophysics Data System (ADS)

    Grygalashvyly, Mykhaylo; Sonnemann, Gerd

    2016-04-01

    In the Earth atmosphere airglow emissions of OH* are used in very diverse branches of research from gravity waves (GWs) and tides observations to minor chemical constituents and temperature measurements. Moreover, the airglow observations have good potential as, for example, for water vapor profile retrieval in the mesopause region. Recently, hydroxyl emissions were found in Mars and in Venus atmospheres. Thus, the applicability potential has been increased in spurts. Even for Earth's atmosphere there is a lack of knowledge on morphology of OH*-layer, i.e. on altitude, number density and shape variability with the intro- and extra-annual cycles, due to planetary waves (PWs), GWs, and tides. The questions on relations between OH* layer altitude, number density (volume emission, intensity), surrounding temperature, and winds (meridional and vertical) are still open. Modern satellite airglow measurements are not enough precise with a typical error in determination of altitude ~2-3 km, while the ground-based measurements are restricted by local point of observations and integrated volume emission. Thus, retrievals of emission altitudes variations to derive are awkward. The difficulties are much stronger for the investigation of the Martian OH*-layer variability and altitude diagnostics. We introduce a simplified analytical approach for OH*-layer altitude in the Martian atmosphere. The expressions for the number density and height of the OH*-layer peak, as well as relationship between both parameters, are derived for night time conditions. These OH*-layer parameters are determined by the temperature, atomic oxygen density and their vertical gradients. The approximations can be useful for analysis of ground-based and satellite-borne airglow observations. We discuss the consequences following from the derived expression.

  18. High altitude, prolonged exercise, and the athlete biological passport.

    PubMed

    Schumacher, Yorck O; Garvican, Laura A; Christian, Ryan; Lobigs, Louisa M; Qi, Jiliang; Fan, Rongyun; He, Yingying; Wang, Hailing; Gore, Christopher J; Ma, Fuhai

    2015-01-01

    The Athlete Biological Passport (ABP) detects blood doping in athletes through longitudinal monitoring of erythropoietic markers. Mathematical algorithms are used to define individual reference ranges for these markers for each athlete. It is unclear if altitude and exercise can affect the variables included in these calculations in a way that the changes might be mistaken for blood manipulation. The aim of this study was to investigate the influence of the simultaneous strenuous exercise and low to high altitude exposure on the calculation algorithms of the ABP. 14 sea level (SL) and 11 altitude native (ALT) highly trained athletes participated in a 14-day cycling stage race taking place at an average altitude of 2496 m above sea level (min. 1014 m, max. 4120 m), race distances ranged between 96 and 227 km per day. ABP blood measures were taken on days -1,3,6,10,14 (SL) and -1,9,15 (ALT) of the race. Four results from three samples of two different SL athletes exceeded the individual limits at the 99% specificity threshold and one value at 99.9%. In ALT, three results from three samples of three different athletes were beyond the individual limits at 99%, one at 99.9%. The variations could be explained by the expected physiological reaction to exercise and altitude. In summary, the abnormalities observed in the haematological ABP´s of well-trained athletes during extensive exercise at altitude are limited and in line with expected physiological changes.

  19. News from KM3NeT

    SciTech Connect

    Katz, Ulrich F.; Collaboration: KM3NeT Collaboration

    2014-11-18

    KM3NeT is a future research infrastructure in the Mediterranean Sea, hosting a multi-cubic-kilometre neutrino telescope and nodes for Earth and Sea sciences. In this report we shortly summarise the genesis of the KM3NeT project and present key elements of its technical design. The physics objectives of the KM3NeT neutrino telescope and some selected sensitivity estimates are discussed. Finally, some first results from prototype operations and the next steps towards implementation – in particular the first construction phase in 2014/15 – are described.

  20. Lidar Altitude Data Read Routine

    Atmospheric Science Data Center

    2013-03-19

    ... Profile products. It is written in Interactive Data Language (IDL) and uses HDF routine calls to read the altitude data which are ... Data Read routine  (1.5 KB) Interactive Data Language (IDL) is available from  Exelis Visual Information Solutions . ...

  1. Altitude Compensating Nozzle Concepts Evaluation

    NASA Technical Reports Server (NTRS)

    Soni, Bharat

    2000-01-01

    This report contains the summary of work accomplished during summer of 2000 by Mr. Chad Hammons, undergraduate senior student, Mississippi State University/ERC in support of NASA/MSFC mission pertinent to Altitude compensating nozzle concepts evaluations. In particular, the development of automatic grid generator applicable in conducting sensitivity analysis involving Aerospike engine is described.

  2. Development of Aptitude at Altitude

    ERIC Educational Resources Information Center

    Hogan, Alexandra M.; Virues-Ortega, Javier; Botti, Ana Baya; Bucks, Romola; Holloway, John W.; Rose-Zerilli, Matthew J.; Palmer, Lyle J.; Webster, Rebecca J.; Baldeweg, Torsten; Kirkham, Fenella J.

    2010-01-01

    Millions of people currently live at altitudes in excess of 2500 metres, where oxygen supply is limited, but very little is known about the development of brain and behavioural function under such hypoxic conditions. We describe the physiological, cognitive and behavioural profile of a large cohort of infants (6-12 months), children (6-10 years)…

  3. Alaska High Altitude Photography Program

    NASA Technical Reports Server (NTRS)

    Petersen, Earl V.; Knutson, Martin A.; Ekstrand, Robert E.

    1986-01-01

    In 1978, the Alaska High Altitude Photography Program was initiated to obtain simultaneous black and white and color IR aerial photography of Alaska. Dual RC-10 and Zeiss camera systems were used for this program on NASA's U-2 and WB-57F, respectively. Data collection, handling, and distribution are discussed as well as general applications and the current status.

  4. Status of KM3NeT

    NASA Astrophysics Data System (ADS)

    Riccobene, G.

    2016-07-01

    The recent observation of cosmic neutrinos by IceCube has pushed the quest towards the identification of cosmic sources of high-energy particles. The KM3NeT Collaboration is now ready to launch the massive construction of detection units to be installed in deep sea to build a km-cubic size neutrino telescope. The main elements of the detector, the status of the project and the expected perfomances are briefly reported.

  5. A genetic mechanism for Tibetan high-altitude adaptation.

    PubMed

    Lorenzo, Felipe R; Huff, Chad; Myllymäki, Mikko; Olenchock, Benjamin; Swierczek, Sabina; Tashi, Tsewang; Gordeuk, Victor; Wuren, Tana; Ri-Li, Ge; McClain, Donald A; Khan, Tahsin M; Koul, Parvaiz A; Guchhait, Prasenjit; Salama, Mohamed E; Xing, Jinchuan; Semenza, Gregg L; Liberzon, Ella; Wilson, Andrew; Simonson, Tatum S; Jorde, Lynn B; Kaelin, William G; Koivunen, Peppi; Prchal, Josef T

    2014-09-01

    Tibetans do not exhibit increased hemoglobin concentration at high altitude. We describe a high-frequency missense mutation in the EGLN1 gene, which encodes prolyl hydroxylase 2 (PHD2), that contributes to this adaptive response. We show that a variant in EGLN1, c.[12C>G; 380G>C], contributes functionally to the Tibetan high-altitude phenotype. PHD2 triggers the degradation of hypoxia-inducible factors (HIFs), which mediate many physiological responses to hypoxia, including erythropoiesis. The PHD2 p.[Asp4Glu; Cys127Ser] variant exhibits a lower K(m) value for oxygen, suggesting that it promotes increased HIF degradation under hypoxic conditions. Whereas hypoxia stimulates the proliferation of wild-type erythroid progenitors, the proliferation of progenitors with the c.[12C>G; 380G>C] mutation in EGLN1 is significantly impaired under hypoxic culture conditions. We show that the c.[12C>G; 380G>C] mutation originated ∼8,000 years ago on the same haplotype previously associated with adaptation to high altitude. The c.[12C>G; 380G>C] mutation abrogates hypoxia-induced and HIF-mediated augmentation of erythropoiesis, which provides a molecular mechanism for the observed protection of Tibetans from polycythemia at high altitude.

  6. How simulated fluence of photons from terrestrial gamma ray flashes at aircraft and balloon altitudes depends on initial parameters

    NASA Astrophysics Data System (ADS)

    Hansen, R. S.; ØStgaard, N.; Gjesteland, T.; Carlson, B.

    2013-05-01

    Up to a few years ago, terrestrial gamma ray flashes (TGFs) were only observed by spaceborne instruments. The aircraft campaign ADELE was able to observe one TGF, and more attempts on aircraft observations are planned. There is also a planned campaign with stratospheric balloons, COBRAT. In this context an important question that arises is what count rates we can expect and how these estimates are affected by the initial properties of the TGFs. Based on simulations of photon propagation in air we find the photon fluence at different observation points at aircraft and balloon altitudes. The observed fluence is highly affected by the initial parameters of the simulated TGFs. One of the most important parameters is the number of initial photons in a TGF. In this paper, we give a semi-analytical approach to find the initial number of photons with an order of magnitude accuracy. The resulting number varies over several orders of magnitude, depending mostly on the production altitude of the TGF. The initial production altitude is also one of the main parameters in the simulations. Given the same number of initial photons, the fluence at aircraft and balloon altitude from a TGF produced at 10 km altitude is 2-3 orders of magnitude smaller then a TGF originating from 20 km altitude. Other important parameters are altitude distribution, angular distribution and amount of feedback. The differences in altitude, altitude distribution and amount of feedback are especially important for the fluence of photons observed at altitudes less than 20 km, and for instruments with a low-energy threshold larger than 100 keV. We find that the maximum radius of observation in 14 km for a TGF with the intensity of an average RHESSI TGF is smaller than the results reported by Smith et al. (2011), and our results support the conclusion in Gjesteland et al. (2012) and Østgaard et al. (2012) that TGFs probably are a more common phenomenon than previously reported.

  7. Altitude characteristics of selected air quality analyzers

    NASA Technical Reports Server (NTRS)

    White, J. H.; Strong, R.; Tommerdahl, J. B.

    1979-01-01

    The effects of altitude (pressure) on the operation and sensitivity of various air quality analyzers frequently flown on aircraft were analyzed. Two ozone analyzers were studied at altitudes from 600 to 7500 m and a nitrogen oxides chemiluminescence detector and a sulfur dioxide flame photometric detector were studied at altitudes from 600 to 3000 m. Calibration curves for altitude corrections to the sensitivity of the instruments are presented along with discussion of observed instrument behavior.

  8. [Children and pregnant women at high altitude].

    PubMed

    Rehakova, P; Rexhaj, E; Farron, F; Duplain, H

    2014-05-07

    Nowadays, high altitude resorts have become popular destinations for family vacations. Based on a limited number of publications and international guidelines, this article summarizes the effects of high altitude on children and pregnant women. Children also suffer from high altitude-related diseases, however their presentation and clinical significance are different from their adult counterparts. Careful planning of the itinerary with respect to altitude of the overnight stays, access to medical services and potential evacuation routes is the cornerstone of a successful vacation.

  9. Low-altitude trapped protons at the geomagnetic equator

    NASA Technical Reports Server (NTRS)

    Guzik, T. G.; Miah, M. A.; Mitchell, J. M.; Wefel, J. P.

    1989-01-01

    Geomagnetically trapped protons in the 0.6- to 9-MeV energy range were measured at latitudes near the geomagnetic equator by the Phoenix 1 experiment on board the S81-1 mission from May to November 1982. The protons show a distribution in latitude along the line of minimum magnetic field strength with a full width at half maximum of about 10 deg but with no appreciable longitudinal variation. Between 170 and 290 Km the peak proton flux shows a fifth-power altitude dependence, in contrast to previous measurements at higher altitudes, possibly demonstrating source attenuation. The efficiency of the telescope is calculated as a function of particle pitch angle and used to investigate the time dependence (1969-1982) of the intensity.

  10. High Altitude Ozone Research Balloon

    NASA Technical Reports Server (NTRS)

    Cauthen, Timothy A.; Daniel, Leslie A.; Herrick, Sally C.; Rock, Stacey G.; Varias, Michael A.

    1990-01-01

    In order to create a mission model of the high altitude ozone research balloon (HAORB) several options for flight preparation, altitude control, flight termination, and payload recovery were considered. After the optimal launch date and location for two separate HAORB flights were calculated, a method for reducing the heat transfer from solar and infrared radiation was designed and analytically tested. This provided the most important advantage of the HAORB over conventional balloons, i.e., its improved flight duration. Comparisons of different parachute configurations were made, and a design best suited for the HAORB's needs was determined to provide for payload recovery after flight termination. In an effort to avoid possible payload damage, a landing system was also developed.

  11. Rocket Altitude Test Facilities Register

    DTIC Science & Technology

    1987-03-01

    Classification of Document UNCLASSIFIED 5. Originator Advisory Group for Aerospace Research and Development North Atlantic Treaty Organization...Emphasis was put on facilities capable of performing research and development tests. This AGARDograph was prepared at the request of the Propulsion... RESEARCH & DEVELOPMENT 7RUEANCELLE 92200 NEUILLY SUR SEINE FRANCE AGARDo^raph N0^97 , Rocket Altitude Test Facilities Register /^ri c^ris

  12. Aero-thermo-dynamic analysis of the Spaceliner-7.1 vehicle in high altitude flight

    NASA Astrophysics Data System (ADS)

    Zuppardi, Gennaro; Morsa, Luigi; Sippel, Martin; Schwanekamp, Tobias

    2014-12-01

    SpaceLiner, designed by DLR, is a visionary, extremely fast passenger transportation concept. It consists of two stages: a winged booster, a vehicle. After separation of the two stages, the booster makes a controlled re-entry and returns to the launch site. According to the current project, version 7-1 of SpaceLiner (SpaceLiner-7.1), the vehicle should be brought at an altitude of 75 km and then released, undertaking the descent path. In the perspective that the vehicle of SpaceLiner-7.1 could be brought to altitudes higher than 75 km, e.g. 100 km or above and also for a speculative purpose, in this paper the aerodynamic parameters of the SpaceLiner-7.1 vehicle are calculated in the whole transition regime, from continuum low density to free molecular flows. Computer simulations have been carried out by three codes: two DSMC codes, DS3V in the altitude interval 100-250 km for the evaluation of the global aerodynamic coefficients and DS2V at the altitude of 60 km for the evaluation of the heat flux and pressure distributions along the vehicle nose, and the DLR HOTSOSE code for the evaluation of the global aerodynamic coefficients in continuum, hypersonic flow at the altitude of 44.6 km. The effectiveness of the flaps with deflection angle of -35 deg. was evaluated in the above mentioned altitude interval. The vehicle showed longitudinal stability in the whole altitude interval even with no flap. The global bridging formulae verified to be proper for the evaluation of the aerodynamic coefficients in the altitude interval 80-100 km where the computations cannot be fulfilled either by CFD, because of the failure of the classical equations computing the transport coefficients, or by DSMC because of the requirement of very high computer resources both in terms of the core storage (a high number of simulated molecules is needed) and to the very long processing time.

  13. Venusian atmospheric equilibrium chemistry at the Pioneer Venus anomalous event altitude

    NASA Technical Reports Server (NTRS)

    Craig, Roger A.

    1994-01-01

    No convincing explanation for the anomalous behavior of the Atmospheric Structure Experiment temperature sensors at approximately 13 km altitude has been found. It occurred on all of the widely-spaced probes, in a similar fashion. A preliminary effort has been made to determine atmospheric chemical species which might be present at 13 km. The purpose of this effort is to initiate suggestions of possible chemical interactions and to explore the effects of the presence of possible metal reactants including condensation. Equilibrium fractions of chemical species were calculated at a variety of conditions. Baseline calculations were made for the altitudes near 13 km. For comparison calculations were also made at 13 km but with the introduction of plausible metal atoms.

  14. Low Altitude Initiation of Ionospheric Upflow and Outflow

    NASA Astrophysics Data System (ADS)

    Burleigh, M.; Zettergren, M. D.; Rowland, D. E.; Klenzing, J.

    2015-12-01

    Significant amounts of ionospheric plasma can be transported to high altitudes (above 1000 km) in response to a variety of plasma heating and uplifting processes. Soft electron precipitation heats ambient, F-region ionospheric electrons creating electron pressure increases and upflows. Strong DC electric fields frictionally heat the ion population also resulting in ion upflows. Lastly, field-aligned thermospheric winds can contribute to ion motion at lower altitudes, while geomagnetically perpendicular winds may affect frictional heating. Once ions have been lifted to high altitudes, transverse ion acceleration by broadband ELF waves can give the upflowing ions sufficient energy to escape into the magnetosphere (ionospheric outflow). This study examines the thermospheric wind regulation of ionospheric upflow and outflow with a focus on how lower ionosphere dynamics feed source populations for transverse energization and determine the types, and amounts, of outflowing ions. The model used here for this study is a 2D ionospheric model based on a modified 16-moment transport description. It solves conservation of mass, momentum, and parallel and perpendicular energy for all relevant ionospheric species. This model encapsulates ionospheric upflow and outflow processes through the inclusion of DC electric fields, and empirical descriptions of heating by soft electron precipitation and BBELF waves. This model is used to conduct a parametric study of neutral wind effects on upflow and outflow and highlights how low-altitude processes affect ion outflow through the regulation of source plasma available to higher altitudes. This model is also used to construct a case study of ion outflows at the nightside polar cap boundary using data from the VISIONS sounding rocket campaign.

  15. In-situ Measurements of the Cosmic Radiation on the Aircraft Altitude over Korean Peninsula

    NASA Astrophysics Data System (ADS)

    Lee, J.; Park, I.; Lee, J.; Oh, S.; Kim, Y. C.

    2014-12-01

    This study presents the comparison between the measured and modeled cosmic radiation on aircraft altitude over Korean peninsula. We performed the measurement with a radiation spectrometer, Liulin-6K on board a Republic of Korea (ROK) Air Force aircraft accomplishing the high-altitude (above 9 km) flight over Korea, and the modeled data was obtained from the operational modeling program, CARI-6M developed by FAA. A number of measurements for the flight mission at high-altitude have been executed to evaluate the exposed dose of cosmic radiation. Both the measured and the calculated data show that the exposed radiation dose enhances dramatically as the altitude increases. The results reveal that the exposed dose rate of aircrews at high-altitude flight is 2-3 orders of magnitude (1-2 mSv/hour) higher than the exposure rate at sea level. It is inferred that the annual total dose of radiation for the aircrews at high-altitude could be higher than the annually public limit (1 mSv) recommended by ICRP. Finally, since neutrons are the dominant components reflecting among total cosmic radiation above 9 km, we try to analyze the relationship between the neutron count from the neutron monitor on the ground and the effective dose from the on board spectrometer. Based on these results, it is suggested that the annual criterion and the proper managing procedure of exposed dose for the flight aircrews of ROK Air Force should be regulated.

  16. Altitude-Related Illness: Advice to Travellers

    PubMed Central

    Crutcher, Rodney A.

    1990-01-01

    Altitude-related medical problems have received much attention in the recent medical literature. Family physicians must be knowledgeable about these problems so that they can give appropriate advice to travellers. The author, a practising family physician, discusses issues arising from both the modest cabin altitudes experienced in modern-day air travel and the greater altitudes experienced by skiers and trekkers, pilots and mountaineers, and lowland adventurers of all sorts. He reviews the process of acclimatization to altitude and the four principal forms of altitude illness. PMID:21233912

  17. Space Operations Center orbit altitude selection strategy

    NASA Technical Reports Server (NTRS)

    Indrikis, J.; Myers, H. L.

    1982-01-01

    The strategy for the operational altitude selection has to respond to the Space Operation Center's (SOC) maintenance requirements and the logistics demands of the missions to be supported by the SOC. Three orbit strategies are developed: two are constant altitude, and one variable altitude. In order to minimize the effect of atmospheric uncertainty the dynamic altitude method is recommended. In this approach the SOC will operate at the optimum altitude for the prevailing atmospheric conditions and logistics model, provided that mission safety constraints are not violated. Over a typical solar activity cycle this method produces significant savings in the overall logistics cost.

  18. Effects of Altitude on Turbojet Engine Performance

    NASA Technical Reports Server (NTRS)

    Fleming, William A

    1951-01-01

    Component and over-all performance characteristics of several turbojet engines investigated in the altitude facilities of the NACA Lewis Laboratory during the last several years are summarized to indicate the effects of altitude on turbojet engine performance. Data presented show that failure of turbojet engine performance to generalize for all altitudes can be traced to reductions in compressor efficiency, corrected air flow, and combustion efficiency at altitude. In addition, it is shown that although engines of different design may have equal thrusts at sea level, the thrusts at altitude may vary widely because of differences in compressor performance characteristics from one engine to another.

  19. The Impact of Moderate-Altitude Staging on Pulmonary Arterial Hemodynamics after Ascent to High Altitude

    DTIC Science & Technology

    2010-01-01

    et al., 1956; Sime et al., 1974). The magnitude of the PAP in- crease plays an important role in the development of high altitude pulmonary edema ...implications for travelers to high altitude. High altitude pulmonary edema (HAPE) is an important cause of high altitude morbidity and mortality, and...P., and Oelz O. (1991). Prevention of high-altitude pulmonary edema by nifedipine. N. Engl. J. Med. 325:1284–1289. Beidleman B.A., Fulco C.S., Muza

  20. Plasma cortisol and testosterone following 19-km and 42-km kayak races.

    PubMed

    Lutoslawska, G; Obminski, Z; Krogulski, A; Sendecki, W

    1991-12-01

    Plasma cortisol and testosterone levels were examined in five, elite, male kayakers before and after 19-km and 42-km kayak races. Both races resulted in significant elevation in plasma cortisol and observed increase is likely to depend on race duration, being much more pronounced after 42-km race compared to 19-km. It should be stressed that observed elevation in cortisol level after 42-km race was higher than reported previously after a marathon run. This finding is in line with reports on hormonal changes in response to arms exercise. Both contests caused a decrease in plasma testosterone level, but the difference between races was not significant. Testosterone/cortisol ratio dropped significantly immediately after the races and the observed decrease was more dominant after the 42-km distance. On the next day, 18 h after the races plasma cortisol, testosterone levels and T/C ratio returned to basal level indicating recuperation from post exercise changes.

  1. High Altitude Observatory YBJ and ARGO Project

    NASA Astrophysics Data System (ADS)

    Tan, Y.; ARGO Collaboration

    A 5800 m2 RPC (Resistive Plate Chamber) full coverage air shower array is under construction in the YangBaJing Cosmic Ray Observatory, Tibet of China, by the ChinaItaly ARGO Collaboration. YBJ is a large flat grassland with an area 10 × 70 km2 at 4300m altitude, about 90 north west from Lhasa. Its nearby power station, asphalt road to Lhasa, passing railway (will be constructed during the coming 5 years), optical fiber link to the INTERNET, rare snow and other favourable weather conditions are well suitable for setting an Astrophysical Observatory here. The installation of a large area carpet-like detector in this peculiar site will allow one to perform an all-sky and high duty cycle study of high energy gamma rays from 100GeV to 50 TeV as well as accurate measurements on UHE cosmic rays. To insure the stable and uniform working condition of RPCs, a 104 M2 carpet hall was constructed, the RPC installation have be started in it since last November. The natural distribution and daily variation of temperature in the hall, the data concerning the performances of the installed RPCs, have been measured, the results are presented. ce

  2. Gravity wave and tidal structures between 60 and 140 km inferred from space shuttle reentry data

    NASA Technical Reports Server (NTRS)

    Fritts, David C.; Wang, Ding-Yi; Blanchard, Robert C.

    1993-01-01

    This study presents an analysis of density measurements made using high-resolution accelerometers aboard several space shuttles at altitudes from 60 to 140 km during reentry into the earth's atmosphere. The observed density fluctuations are interpreted in terms of gravity waves and tides and provide evidence of the importance of such motions well into the thermosphere. Height profiles of fractional density variance reveal that wave amplitudes increase at a rate consistent with observations at lower levels up to about 90 km. The rate of amplitude growth decreases at greater heights, however, and appears to cease above about 110 km. Wave amplitudes are nevertheless large at these heights and suggest that gravity waves may play an important role in forcing of the lower thermosphere.

  3. Daytime vertical and zonal velocities from 150-km echoes: Their relevance to F-region dynamics

    NASA Astrophysics Data System (ADS)

    Chau, Jorge L.; Woodman, Ronald F.

    2004-09-01

    As it was suggested by Kudeki and Fawcett [1993], and later shown by Woodman and Villanueva [1995], vertical Doppler velocities of daytime 150-km echoes represent the vertical E × B drift velocities at F region altitudes. Recently a special experiment was conducted to compare not only the vertical but also the zonal velocities from 150-km echoes with those from an incoherent scatter radar (ISR) mode perpendicular to the magnetic field. The vertical velocity comparisons show that (1) there is a very good agreement between 150-km velocity and the mean F-region E × B drift, and (2) much better agreement is found with the extrapolated values from the ISR altitudinal profiles. On the other hand poor-to-good agreement is found between their zonal components. Our preliminary zonal velocity results, indicate that there is a poor agreement before noontime, while better agreement is found in the afternoon.

  4. Gravity wave and tidal structures between 60 and 140 km inferred from space shuttle reentry data

    SciTech Connect

    Fritts, D.C. ); Dingyi Wang ); Blanchard, R.C. )

    1993-03-15

    This study presents an analysis of density measurements made using high-resolution accelerometers aboard several space shuttles at altitudes from 60 to 140 km during reentry into the earth's atmosphere. The observed density fluctuations are interpreted in terms of gravity waves and tides and provide evidence of the importance of such motions well into the thermosphere. Height profiles of fractional density variance reveal that wave amplitudes increase at a rate consistent with observations at lower levels up to [approximately]90 km. The rate of amplitude growth decreases at greater heights, however, and appears to cease above [approximately]110 km. Wave amplitudes are nevertheless large at these heights and suggest that gravity waves may play an important role in forcing of the lower thermosphere.

  5. Monthly mean global climatology of temperature, wind, geopotential height and pressure for 0-120 km

    NASA Technical Reports Server (NTRS)

    Chandra, Sushil; Schoeberl, Mark R.; Fleming, Eric L.; Barnett, John J.

    1990-01-01

    This paper presents a monthly mean climatology of zonal mean temperature, zonal wind, and geopotential height with nearly pole-to-pole coverage (80 deg S-80 deg N) for 0-120 km which can be used as a function of altitude and pressure. This climatology reproduces most of the characteristic features of the atmosphere such as the lowering and cooling of the mesopause and the lowering and warming of the stratopause during the summer months at high latitudes. A series of zonal wind profiles is also presented comparing this climatological wind with monthly mean climatological direct wind measurements in the upper mesosphere and lower thermosphere. The two data sets compare well below 80 km, with some general seasonal trend agreement observed above 80 km. The zonal wind at the equator presented here simulates the observed features of the semiannual oscillation in the upper stratosphere and mesosphere.

  6. Rummy high-altitude pressure measurements and analysis

    SciTech Connect

    Banister, J.R.; Hereford, W.V.

    1982-01-01

    Five pressure-measurement canisters equipped with parachutes were deployed from an A7C aircraft on the Rummy test. Their altitudes above Yucca flat were over 8.5 km when the pressure pulse arrived. Three successful measurements were obtained. These time histories showed a more complicated behavior than histories obtained on Pahute Mesa tests because the Rummy event developed double spall closures over a large area. Excellent agreement was obtained between the observed pressure histories and those calculated from surface acceleration measurements. The Yucca Flat terrain was so level that pressure pulses were not appreciably changed or weakened by elevation differences.

  7. SAGE II aerosol validation - Selected altitude measurements, including particle micromeasurements

    NASA Technical Reports Server (NTRS)

    Oberbeck, Verne R.; Russell, Philip B.; Pueschel, Rudolf F.; Snetsinger, Kenneth G.; Ferry, Guy V.; Livingston, John M.; Rosen, James N.; Osborn, Mary T.; Kritz, Mark A.

    1989-01-01

    The validity of particulate extinction coefficients derived from limb path solar radiance measurements obtained during the Stratospheric Aerosol and Gas Experiment (SAGE) II is tested. The SAGE II measurements are compared with correlative aerosol measurements taken during January 1985, August 1985, and July 1986 with impactors, laser spectrometers, and filter samplers on a U-2 aircraft, an upward pointing lidar on a P-3 aircraft, and balloon-borne optical particle counters. The data for July 29, 1986 are discussed in detail. The aerosol measurements taken on this day at an altitude of 20.5 km produce particulate extinction values which validate the SAGE II values for similar wavelengths.

  8. High altitude balloons with ultra thin polyethylene films for scientific observations

    NASA Astrophysics Data System (ADS)

    Nishimura, J.; Saito, Y.; Matsuzaka, Y.; Namiki, M.; Toriumi, M.; Yokota, R.; Yamagami, T.; Hirosawa, H.; Matsushima, K.

    Development of a balloon flying at higher altitude is one of the most attractive trial for the balloon technology. We, the balloon group at the Institute of Space and Astronautical Science (ISAS), have been engaged in the development since 1991. Our concept is to make a light balloon to go higher. We have developed light equipment for house keeping modules and a ultra-thin film with a thickness of only 3.4 μm. Using these equipments and the film, we launched a balloon with a volume of 30,000 m3 to reach the highest altitude of 50.8 km, which is the highest altitude ever reached by Japanese balloons. In this spring, we are going to launch a balloon with a volume of 60,000 m3 , which is expected to make a new record of the balloon altitude. We are going to report the result of the experiment.

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

    DTIC Science & Technology

    2010-04-01

    69° N ( Andenes , Norway) and 85 235 km geometric altitude in Figure 5. In addition, we performed five short term integrations of the 236 forecast...intercomparison between two approaches to calculating winds and the Andenes data. 251 252 2.2 Ice Particle Trajectories and CARMA 253 254 As noted

  10. MODIS 3 km and 10 km aerosol optical depth for China: Evaluation and comparison

    NASA Astrophysics Data System (ADS)

    He, Qingqing; Zhang, Ming; Huang, Bo; Tong, Xuelian

    2017-03-01

    The recently released Moderate Resolution Imaging Spectrometer (MODIS) Collection 6 introduced a fine scale aerosol optical depth (AOD) distribution, the 3 km product, which is expected to perform well in analyzing aerosols and identifying local air pollution, especially in the severely polluted atmosphere of China. However, few detailed evaluations of regional variations have been conducted. In this paper, we evaluate MODIS 3 km and 10 km AOD products for China against ground-based measurements and compare their performance with respect to spatial and temporal variations. The ground validations indicate that the two products are generally correlated well to ground-based observations. Spatially, the 3 km product slightly outperform the 10 km product in well-developed areas of southern China. Temporally, both products perform worse during spring and summer. Atmospheric clouds and underlying surface are two key factors that influence the accuracy and number of retrievals for both products. The comparison analysis reveals the newly introduced AOD product clearly shows good relationships with the coarse resolution retrievals in spatial and temporal variation but significant differences regarding details. The 3 km AOD product provides better aerosol gradients, more retrievals in bare areas of western China and some spikes of diurnal variation in cloudy days. Seasonal comparisons show the 3 km AOD product is higher than the 10 km product in all seasons, especially during spring and summer. Although the 3 km product for China generally performs slightly worse than the 10 km product, the added information of the MODIS 3 km AOD product shows potential for studying local aerosol characterization, and may facilitate studies of air pollution.

  11. Pulmonary Adaptation to High Altitude.

    DTIC Science & Technology

    1982-08-01

    Fluorometric assays of high energy phosphates in respiratory and limb muscles plus a variety of histochemical techniques to more fully describe the...phenomenon--in the form of the critical level of CO2 required to maintain rhythmic breathing during sleep and explains the effect of acute oxygen therapy on...AD-AR140 51.4 PULMONARY ADAPTATION TO HIGH ALTITUDE(U) WISCONSIN i/i UNIV-MADISON J R DEMPSEY AUG 82 DAMD17-77-C-786 UNCLAS51FIED F/G 619 ML

  12. Altitude effects on growth of indigenous children in Oaxaca, Southern Mexico.

    PubMed

    Little, Bertis B; Malina, Robert M; Pena Reyes, Maria Eugenia; Bali Chavez, Guillermo

    2013-09-01

    The effect of altitude of residence on the growth status of 11,454 indigenous school children 6-14 years of age in Oaxaca, southern Mexico, was examined. Indicators of living conditions (human development index [HDI], index of community nutritional risk [INR], index of marginalization [IM], index of relative isolation [II]) were regressed on z-scores for height, weight and BMI, and the residuals were regressed on altitude of residence (km). Independent of other environmental conditions, altitude negatively affected height by approximately -0.07 z-scores per kilometer altitude above sea level. The estimated average decrease in stature was 0.92 cm per kilometer elevation. BMI was significantly increased, 1.2 units per kilometer elevation, consistent with earlier studies of growth status and altitude. In contrast, weight was not affected by altitude of residence. Approximately 36% of the reduction in height and 54% of the increase in BMI were due to altitude effects; the remaining changes in height and BMI were associated with environmental factors reflected in the indices of community well-being considered.

  13. A case study on the possible altitude-dependent effects of collisions on sodium airglow emission

    NASA Astrophysics Data System (ADS)

    Sarkhel, S.; Sekar, R.; Chakrabarty, D.; Sridharan, S.

    2010-10-01

    Simultaneous observations of a narrowband sodium (Na) airglow photometer corresponding to the D2 line in conjunction with a Na lidar from Gadanki (13.5°N, 79.2°E), India, reveal episodic enhancements in Na airglow intensity during 1930-0142 Indian standard time (IST; IST = UT + 5.5 h) on 18-19 March 2007. This variation is drastically different from the average Na airglow intensity variation for that duration during that month. Interestingly, the Na airglow intensity variation is found to be well correlated with the Na atom concentration variation only at 93.6 km during the period 2312-0142 IST, a period closer to the measurement of mesospheric ozone by the Sounding of Atmosphere using Broadband Emission Radiometry (SABER) instrument on board the Thermosphere Ionosphere Mesosphere Energetics and Dynamics (TIMED) satellite. Moreover, the correlation coefficient is not significant at 88.5 km, where the Na concentration is maximum. Estimations of the altitude profiles of the volume emission rate of Na airglow corresponding to the D2 line using measured parameters during local postmidnight hours reveal that the peak of volume emission rate is different from 93.6 km. It is suggested that the altitude variation in collisional quenching is needed to match the peak altitude of emission to the altitude where correlation between the Na atom concentration and Na airglow intensity is maximum. The fact that the measured atmospheric pressure reduces by a factor of ˜2.5 as altitude changes from 88.5 to 93.6 km supports this proposition. The case study brings out the sensitivity of Na airglow intensity to the altitude dependence of the collisional quenching that eventually affects Na airglow emission.

  14. Lidar Observations of Tropical High-altitude Cirrus Clouds: Results form Dual Wavelength Raman Lidar Measurements During the ALBATROSS Campaign 1996

    NASA Technical Reports Server (NTRS)

    Neuber, R.; Wegener, Alfred; Schrems, O.; McDermid, I. S.

    1997-01-01

    Results from dual wavelength Raman Lidar Observations of tropical high-altitude cirrus clouds are reported. Based on 107 hours of night-time measurements cirrus cloud were present in more than 50% of the observations at latitudes between 23.5 degress S and 23.5 degrees N and altitudes between 11 and 16km.

  15. Magnetospheric plasma studies using data from the dynamics high and low altitude plasma instruments

    NASA Astrophysics Data System (ADS)

    Barfield, J. N.

    1984-05-01

    Plasma measurements made on Dynamics Explorer 1 and 2 spacecraft are providing new information on the altitude dependence of polar-cap plasma populations, their sources, and the acceleration processes they undergo. This study found that the polar-rain electron population apparently exhibits no significant altitude dependence between altitudes of a few hundred to approximately 20,000 km. This result was expected from the magnetosheath-like energy spectrum of the low-altitude polar rain. In this case of the polar wind, a significant velocity increase was theoretically predicted to occur between the two spacecraft altitudes, and this effect was confirmed by DE-1 plasma measurements. A major result of this study of the accelerated polar wind is its significant conic component, which indicates that the ions are heated perpendicularly as they emerge from the polar-cap ionosphere. The gradual decrease in polar-wind energy observed to occur from the cusp across to the nightside polar cap suggests that the perpendicular heating process, probably in cyclotron waves, is most intense near the cusp region. Significant altitude effects are also observed in the plasmas that occupy magnetic flux tubes connected to polar-cap auroral arcs (or theta auroras). At DE-2, typical low-energy (approximately 100 eV) inverted-V electron distributtions are observed. At DE-1 the electron and positive-ion distribution functions are consistent with electrostatic potential drops that are at times below the typical DE-1 altitude of 15,000 to 20,000 km and at times above these altitudes.

  16. The estimation of 550 km x 550 km mean gravity anomalies. [from free atmosphere gravimetry data

    NASA Technical Reports Server (NTRS)

    Williamson, M. R.; Gaposchkin, E. M.

    1975-01-01

    The calculation of 550 km X 550 km mean gravity anomalies from 1 degree X 1 degree mean free-air gravimetry data is discussed. The block estimate procedure developed by Kaula was used, and estimates for 1452 of the 1654 blocks were obtained.

  17. ALT space shuttle barometric altimeter altitude analysis

    NASA Technical Reports Server (NTRS)

    Killen, R.

    1978-01-01

    The accuracy was analyzed of the barometric altimeters onboard the space shuttle orbiter. Altitude estimates from the air data systems including the operational instrumentation and the developmental flight instrumentation were obtained for each of the approach and landing test flights. By comparing the barometric altitude estimates to altitudes derived from radar tracking data filtered through a Kalman filter and fully corrected for atmospheric refraction, the errors in the barometric altitudes were shown to be 4 to 5 percent of the Kalman altitudes. By comparing the altitude determined from the true atmosphere derived from weather balloon data to the altitude determined from the U.S. Standard Atmosphere of 1962, it was determined that the assumption of the Standard Atmosphere equations contributes roughly 75 percent of the total error in the baro estimates. After correcting the barometric altitude estimates using an average summer model atmosphere computed for the average latitude of the space shuttle landing sites, the residual error in the altitude estimates was reduced to less than 373 feet. This corresponds to an error of less than 1.5 percent for altitudes above 4000 feet for all flights.

  18. Altitude Stress During Participation of Medical Congress.

    PubMed

    Kim, Soon Bae; Kim, Jong Sung; Kim, Sang Jun; Cho, Su Hee; Suh, Dae Chul

    2016-09-01

    Medical congresses often held in highlands. We reviewed several medical issues associated with altitude stress especially while physicians have participated medical congress held in high altitude. Altitude stress, also known as an acute mountain sickness (AMS), is caused by acute exposure to low oxygen level at high altitude which is defined as elevations at or above 1,200 m and AMS commonly occurs above 2,500 m. Altitude stress with various symptoms including insomnia can also be experienced in airplane. AMS and drunken state share many common features in symptoms, neurologic manifestations and even show multiple microbleeds in corpus callosum and white matter on MRI. Children are more susceptible to altitude stress than adults. Gradual ascent is the best method for the prevention of altitude stress. Adequate nutrition (mainly carbohydrates) and hydration are recommended. Consumption of alcohol can exacerbate the altitude-induced impairments in judgment and the visual senses and promote psychomotor dysfunction. For prevention or treatment of altitude stress, acetazolamide, phosphodiesterase inhibitors, dexamethasone and erythropoietin are helpful. Altitude stress can be experienced relatively often during participation of medical congress. It is necessary to remind the harmful effect of AMS because it can cause serious permanent organ damage even though the symptoms are negligible in most cases.

  19. Altitude Stress During Participation of Medical Congress

    PubMed Central

    Kim, Soon Bae; Kim, Jong Sung; Kim, Sang Jun; Cho, Su Hee

    2016-01-01

    Medical congresses often held in highlands. We reviewed several medical issues associated with altitude stress especially while physicians have participated medical congress held in high altitude. Altitude stress, also known as an acute mountain sickness (AMS), is caused by acute exposure to low oxygen level at high altitude which is defined as elevations at or above 1,200 m and AMS commonly occurs above 2,500 m. Altitude stress with various symptoms including insomnia can also be experienced in airplane. AMS and drunken state share many common features in symptoms, neurologic manifestations and even show multiple microbleeds in corpus callosum and white matter on MRI. Children are more susceptible to altitude stress than adults. Gradual ascent is the best method for the prevention of altitude stress. Adequate nutrition (mainly carbohydrates) and hydration are recommended. Consumption of alcohol can exacerbate the altitude-induced impairments in judgment and the visual senses and promote psychomotor dysfunction. For prevention or treatment of altitude stress, acetazolamide, phosphodiesterase inhibitors, dexamethasone and erythropoietin are helpful. Altitude stress can be experienced relatively often during participation of medical congress. It is necessary to remind the harmful effect of AMS because it can cause serious permanent organ damage even though the symptoms are negligible in most cases. PMID:27621942

  20. Applying WebMining on KM system

    NASA Astrophysics Data System (ADS)

    Shimazu, Keiko; Ozaki, Tomonobu; Furukawa, Koichi

    KM (Knowledge Management) systems have recently been adopted within the realm of enterprise management. On the other hand, data mining technology is widely acknowledged within Information systems' R&D Divisions. Specially, acquisition of meaningful information from Web usage data has become one of the most exciting eras. In this paper, we employ a Web based KM system and propose a framework for applying Web Usage Mining technology to KM data. As it turns out, task duration varies according to different user operations such as referencing a table-of-contents page, down-loading a target file, and writing to a bulletin board. This in turn makes it possible to easily predict the purpose of the user's task. By taking these observations into account, we segmented access log data manually. These results were compared with results abstained by applying the constant interval method. Next, we obtained a segmentation rule of Web access logs by applying a machine-learning algorithm to manually segmented access logs as training data. Then, the newly obtained segmentation rule was compared with other known methods including the time interval method by evaluating their segmentation results in terms of recall and precision rates and it was shown that our rule attained the best results in both measures. Furthermore, the segmented data were fed to an association rule miner and the obtained association rules were utilized to modify the Web structure.

  1. Km3Net Italy - Seafloor network

    NASA Astrophysics Data System (ADS)

    Papaleo, Riccardo

    2016-04-01

    The KM3NeT European project aims to construct a large volume underwater neutrino telescope in the depths of the Mediterranean Sea. INFN and KM3NeT collaboration, thanks to a dedicated funding of 21.000.000 € (PON 2007-2013), are committed to build and deploy the Phase 1 of the telescope, composed of a network of detection units: 8 towers, equipped with single photomultiplier optical modules, and 24 strings, equipped with multi-photomultipliers optical modules. All the towers and strings are connected to the main electro optical cable by means of a network of junction boxes and electro optical interlink cables. Each junction box is an active node able to provide all the necessary power to the detection units and to guarantee the data transmission between the detector and the on-shore control station. The KM3NeT Italia project foresees the realization and the installation of the first part of the deep sea network, composed of three junction boxes, one for the towers and two for the strings. In July 2015, two junction boxes have been deployed and connected to the new cable termination frame installed during the same sea campaign. The third and last one will be installed in November 2015. The status of the deep sea network is presented together with technical details of the project.

  2. High-altitude reconnaissance aircraft

    NASA Technical Reports Server (NTRS)

    Yazdi, Renee Anna

    1991-01-01

    At the equator the ozone layer ranges from 65,000 to 130,000+ ft, which is beyond the capabilities of the ER-2, NASA's current high-altitude reconnaissance aircraft. This project is geared to designing an aircraft that can study the ozone layer. The aircraft must be able to satisfy four mission profiles. The first is a polar mission that ranges from Chile to the South Pole and back to Chile, a total range of 6000 n.m. at 100,000 ft with a 2500-lb payload. The second mission is also a polar mission with a decreased altitude and an increased payload. For the third mission, the aircraft will take off at NASA Ames, cruise at 100,000 ft, and land in Chile. The final mission requires the aircraft to make an excursion to 120,000 ft. All four missions require that a subsonic Mach number be maintained because of constraints imposed by the air sampling equipment. Three aircraft configurations were determined to be the most suitable for meeting the requirements. The performance of each is analyzed to investigate the feasibility of the mission requirements.

  3. Rocket Engine Altitude Simulation Technologies

    NASA Technical Reports Server (NTRS)

    Woods, Jody L.; Lansaw, John

    2010-01-01

    John C. Stennis Space Center is embarking on a very ambitious era in its rocket engine propulsion test history. The first new large rocket engine test stand to be built at Stennis Space Center in over 40 years is under construction. The new A3 Test Stand is designed to test very large (294,000 Ibf thrust) cryogenic propellant rocket engines at a simulated altitude of 100,000 feet. A3 Test Stand will have an engine testing chamber where the engine will be fired after the air in the chamber has been evacuated to a pressure at the simulated altitude of less than 0.16 PSIA. This will result in a very unique environment with extremely low pressures inside a very large chamber and ambient pressures outside this chamber. The test chamber is evacuated of air using a 2-stage diffuser / ejector system powered by 5000 lb/sec of steam produced by 27 chemical steam generators. This large amount of power and flow during an engine test will result in a significant acoustic and vibrational environment in and around A3 Test Stand.

  4. Multiple Peaks in SABER Mesospheric OH Emission Altitude Profiles

    NASA Astrophysics Data System (ADS)

    Rozum, J. C.; Ware, G. A.; Baker, D. J.; Mlynczak, M. G.; Russell, J. M.

    2012-12-01

    Since January 2002, the SABER instrument aboard the TIMED satellite has been performing limb-scan measurements of the altitude distribution of the hydroxyl airglow. The majority of the SABER 1.6 μm and 2.0 μm OH volume emission rate (VER) profiles manifest a single peak at around 90 km, and are roughly gaussian in shape. However, a significant number (approximately 10% in nighttime) of these VER profiles have an irregular characteristic of multiple peaks that are comparable in brightness to the absolute maximum. The origin of these multiple peaks in SABER profiles is currently being studied. Single peak and irregular SABER OH VER profiles are compared with OH VER altitude curves obtained via theoretical vertical distribution models. In addition, we compare SABER profiles with OH VER altitude profiles obtained from rocket-borne radiometric experiments. The techniques of Liu and Shepherd's analysis of double-peaked emission profiles obtained by the Wind Imaging Interferometer (WINDII) using similar scan geometry are applied. The geographical distribution of the SABER nighttime multiple-peak VER profiles in the 1.6 μm and 2.0 μm channels is presented, as are the distributions of these profiles with respect to instrument-scan geometry parameters. It is noted that during the night, multiple peak profiles are more common at equatorial latitudes. A relationship has been found between the geographical distribution of two-peaked profiles and spatial orientation of the SABER instrument's viewing field.

  5. Barometric pressures at extreme altitudes on Mt. Everest: physiological significance.

    PubMed

    West, J B; Lahiri, S; Maret, K H; Peters, R M; Pizzo, C J

    1983-05-01

    Barometric pressures were measured on Mt. Everest from altitudes of 5,400 (base camp) to 8,848 m (summit) during the American Medical Research Expedition to Everest. Measurements at 5,400 m were made with a mercury barometer, and above this most of the pressures were obtained with an accurate crystal-sensor barometer. The mean daily pressures were 400.4 +/- 2.7 (SD) Torr (n = 35) at 5,400 m, 351.0 +/- 1.0 Torr (n = 16) at 6,300 m, 283.6 +/- 1.5 Torr (n = 6) at 8,050 m, and 253.0 Torr (n = 1) at 8,848 m. All these pressures are considerably higher than those predicted from the ICAO Standard Atmosphere. The chief reason is that pressures at altitudes between 2 and 16 km are latitude dependent, being higher near the equator because of the large mass of cold air in the stratosphere of that region. Data from weather balloons show that the pressure at the altitude of the summit of Mt. Everest varies considerably with season, being about 11.5 Torr higher in midsummer than in midwinter. Although the mountain has been climbed without supplementary O2, the very low O2 partial pressure at the summit means that it is at the limit of man's tolerance, and even day-by-day variations in barometric pressure apparently affect maximal O2 uptake.

  6. Intersystem collisional transfer of excitation in low altitude aurora

    NASA Astrophysics Data System (ADS)

    Benesch, W.

    1983-03-01

    The characteristics of auroral optical emission as a function of altitude are exploited as a source of data for the investigation of the intersystem collisional transfer (ICT) of excitation in the nitrogen molecule. The procedure is based on a recently proposed model for the generation of the red lower border of type B auroras as resulting from the effect of the increased collision frequency at lower altitudes on the distribution of population within the excited molecules. In particular, the 85 km turn-on altitude for the red lower border of auroral arcs provides an indicator for the determination of the density and pressure required for the onset of the ICT process at mesopause temperatures. Values are obtained for collision cross sections and rate constants for the coupling of neighboring vibrational levels in adjacent electronic states in nitrogen. The results are compared with the findings of several laboratory studies on similar collisional transfers among nested electronic states. A two-part process is suggested to account for the observed features of intersystem collisional transfer phenomena.

  7. Description of the strategic high-altitude atmospheric radiation code (SHARC). Scientific report, Jan 89-Oct 90

    SciTech Connect

    Duff, J.W.; Sundberg, R.L.; Gruninger, J.H.; Bernstein, L.S.; Robertson, D.C.

    1990-11-27

    The report describes an upgraded version of the strategic high-altitude radiance code, SHARC-2. SHARC calculates atmospheric radiance and transmittance over the 2-40 micrometer spectral region for arbitrary paths within 50 and 300 km altitude, including space viewing. It models radiation due to NLTE (Non-Local Thermodynamic Equilibrium) molecular emissions which are the dominant sources at these altitudes. This new version, which is now ready for distribution, has been upgraded to include a fully integrated auroral model with time-dependent chemistry, extention down to 50 km altitude, and radiation from the minor isotopes of CO2. In addition, there have been numerous internal upgrades to the various modules. These include a Voigt lineshape for the radiative excitation module; embedding of the auroral region into a quiescent atmosphere; and improvements in the radiation transport algorithms.

  8. Measurement of Altitude in Blind Flying

    NASA Technical Reports Server (NTRS)

    Brombacher, W G

    1934-01-01

    In this note, instruments for measuring altitude and rate of change of altitude in blind flying and landing of aircraft and their performance are discussed. Of those indicating the altitude above ground level, the sonic altimeter is the most promising. Its present bulk, intermittent operation, and more or less unsatisfactory means of indication are serious drawbacks to its use. The sensitive type aneroid altimeter is also discussed and errors in flying at a pressure level and in landing are discussed in detail.

  9. Theoretical atmospheric transmission in the mid-and far-infrared at four altitudes.

    PubMed

    Traub, W A; Stier, M T

    1976-02-01

    The ir transmission of the terrestrial atmosphere is calculated at four altitudes of interest: Mauna Kea at 4.2 km (2-1000 microm), aircraft at 14 km (5-1000 microm), and balloon at 28 km and 41 km (10-1000 microm). We show both high resolution spectra (0.05 cm(-1)) and broadband averages. The results are intended to serve both as a detailed guide to the interference that is expected from the atmosphere for astronomical spectroscopy and also as an indicator of the relative change in absorption and emission that can be expected at various observing altitudes. One salient result for the spectral region around 100 microm is that the absorption (and emissivity) of the atmosphere drops by a factor of 10 for each increase in altitude of 15 km throughout the aircraft and balloon range; thus balloon-borne astronomical photometry and spectroscopy should both enjoy a considerable advantage over aircraft observations in the 30-300-microm region.

  10. Hormonal contraceptives and travel to high altitude.

    PubMed

    Keyes, Linda E

    2015-03-01

    Women frequently ask about the safety and efficacy of using hormonal contraception (HC), either oral contraceptive pills (OC) or other forms, when traveling to high altitude locales. What are the risks and benefits of using HC at high altitude? Does HC affect acclimatization, exercise performance, or occurrence of acute mountain sickness? This article reviews current data regarding the risks and benefits of HC at high altitude, both demonstrated and theoretical, with the aim of helping health care providers to advise women traveling above 2500 meters. Most healthy women can safely use HC when traveling to high altitude, but should be aware of the potential risks and inconveniences.

  11. High altitude medicine education in China: exploring a new medical education reform.

    PubMed

    Luo, Yongjun; Luo, Rong; Li, Weiming; Huang, Jianjun; Zhou, Qiquan; Gao, Yuqi

    2012-03-01

    China has the largest plateau in the world, which includes the whole of Tibet, part of Qinghai, Xinjiang, Yunnan, and Sichuan. The plateau area is about 257.2×10(4) km(2), which accounts for about 26.8% of the total area of China. According to data collected in 2006, approximately twelve million people were living at high altitudes, between 2200 to 5200 m high, on the Qinghai-Tibetan Plateau. Therefore, there is a need for medical workers who are trained to treat individuals living at high altitudes. To train undergraduates in high altitude medicine, the College of High Altitude Military Medicine was set up at the Third Military Medical University (TMMU) in Chongqing in 1999. This is the only school to teach high altitude medicine in China. Students at TMMU study natural and social sciences, basic medical sciences, clinical medical sciences, and high altitude medicine. In their 5(th) year, students work as interns at the General Hospital of Tibet Military Command in Lhasa for 3 months, where they receive on-site teaching. The method of on-site teaching is an innovative approach for training in high altitude medicine for undergraduates. Three improvements were implemented during the on-site teaching component of the training program: (1) standardization of the learning progress; (2) integration of formal knowledge with clinical experience; and (3) coaching students to develop habits of inquiry and to engage in ongoing self-improvement to set the stage for lifelong learning. Since the establishment of the innovative training methods in 2001, six classes of high altitude medicine undergraduates, who received on-site teaching, have graduated and achieved encouraging results. This evidence shows that on-site teaching needs to be used more widely in high altitude medicine education.

  12. Radiation Safety Issues in High Altitude Commercial Aircraft

    NASA Technical Reports Server (NTRS)

    Wilson, John W.; Cucinotta, Francis A.; Shinn, Judy L.

    1995-01-01

    The development of a global economy makes the outlook for high speed commercial intercontinental flight feasible, and the development of various configurations operating from 20 to 30 km have been proposed. In addition to the still unresolved issues relating to current commercial operations (12-16 km), the higher dose rates associated with the higher operating altitudes makes il imperative that the uncertainties in the atmospheric radiation environment and the associated health risks be re-examined. Atmospheric radiation associated with the galactic cosmic rays forms a background level which may, under some circumstances, exceed newly recommended allowable exposure limits proposed on the basis of recent evaluations of the A -bomb survivor data (due to increased risk coefficients). These larger risk coefficients, within the context of the methodology for estimating exposure limits, are resulting in exceedingly low estimated allowable exposure limits which may impact even present day flight operations and was the reason for the CEC workshop in Luxembourg (1990). At higher operating altitudes, solar particles events can produce exposures many orders of magnitude above background levels and pose significant health risks to the most sensitive individuals (such as during pregnancy). In this case the appropriate quality factors are undefined, and some evidence exists which indicates that the quality factor for stochastic effects is a substantial underestimate.

  13. Change in turbopause altitude at 52 and 70° N

    NASA Astrophysics Data System (ADS)

    Hall, C. M.; Holmen, S. E.; Meek, C. E.; Manson, A. H.; Nozawa, S.

    2015-07-01

    The turbopause is the demarkation between atmospheric mixing by turbulence (below) and molecular diffusion (above). When studying concentrations of trace species in the atmosphere, and particularly long-term change, it may be important to understand processes present, together with their temporal evolution, that may be responsible for redistribution of atmospheric constituents. The general region of transition between turbulent and molecular mixing coincides with the base of the ionosphere, the lower region in which molecular oxygen is dissociated, and, at high latitude in summer, the coldest part of the whole atmosphere. This study updates previous reports of turbopause altitude, extending the time series by half a decade, and thus shedding new light on the nature of change over solar-cycle timescales. Assuming there is no trend in temperature, at 70° N there is evidence for a summer trend of ~ 1.2 km decade-1, but for winter and at 52° N there is no significant evidence for change at all. If the temperature at 90 km is estimated using meteor trail data, it is possible to estimate a cooling rate, which, if applied to the turbopause altitude estimation, fails to alter the trend significantly irrespective of season. While studies of atomic oxygen density, [O], using mid-latitude timeseries dating from 1975, show positive trends which can be explained by a lowering of the turbopause, [O] exhibits negative trends since 2002 that, although at a different latitude, are compatible with the observed increase in turbopause height reported here.

  14. Change in turbopause altitude at 52 and 70° N

    NASA Astrophysics Data System (ADS)

    Hall, Chris M.; Holmen, Silje E.; Meek, Chris E.; Manson, Alan H.; Nozawa, Satonori

    2016-02-01

    The turbopause is the demarcation between atmospheric mixing by turbulence (below) and molecular diffusion (above). When studying concentrations of trace species in the atmosphere, and particularly long-term change, it may be important to understand processes present, together with their temporal evolution that may be responsible for redistribution of atmospheric constituents. The general region of transition between turbulent and molecular mixing coincides with the base of the ionosphere, the lower region in which molecular oxygen is dissociated, and, at high latitude in summer, the coldest part of the whole atmosphere. This study updates previous reports of turbopause altitude, extending the time series by half a decade, and thus shedding new light on the nature of change over solar-cycle timescales. Assuming there is no trend in temperature, at 70° N there is evidence for a summer trend of ˜ 1.6 km decade-1, but for winter and at 52° N there is no significant evidence for change at all. If the temperature at 90 km is estimated using meteor trail data, it is possible to estimate a cooling rate, which, if applied to the turbopause altitude estimation, fails to alter the trend significantly irrespective of season. The observed increase in turbopause height supports a hypothesis of corresponding negative trends in atomic oxygen density, [O]. This supports independent studies of atomic oxygen density, [O], using mid-latitude time series dating from 1975, which show negative trends since 2002.

  15. Direct simulation of three-dimensional flow about the AFE vehicle at high altitudes

    NASA Technical Reports Server (NTRS)

    Celenligil, M. Cevdet; Moss, James N.; Bird, Graeme A.

    1988-01-01

    Three-dimensional hypersonic rarefied flow about the Aeroassist Flight Experiment (AFE) vehicle was studied using the direct simulation Monte Carlo (DSMC) technique. Results are presented for the transitional flow regime encountered between 120 and 200 km altitudes with a reentry velocity of 9.92 km/s. In the simulations, a five-species reacting real-gas model that accounts for internal energies (rotational and vibrational) is used. The results indicate that the transitional effects are significant even at an altitude of 200 km and influence the overall vehicle aerodynamics. For the cases considered, the aerodynamic coefficients, surface pressures, convective heating, and flow field structure variations with rarefaction effects are presented.

  16. Exhaust emission calibration of two J-58 afterburning turbojet engines at simulated high-altitude, supersonic flight conditions

    NASA Technical Reports Server (NTRS)

    Holdeman, J. D.

    1976-01-01

    Emissions of total oxides of nitrogen, nitric oxide, unburned hydrocarbons, carbon monoxide, and carbon dioxide from two J-58 afterburning turbojet engines at simulated high-altitude flight conditions are reported. Test conditions included flight speeds from Mach 2 to 3 at altitudes from 16.0 to 23.5 km. For each flight condition exhaust measurements were made for four or five power levels, from maximum power without afterburning through maximum afterburning. The data show that exhaust emissions vary with flight speed, altitude, power level, and radial position across the exhaust. Oxides of nitrogen emissions decreased with increasing altitude and increased with increasing flight speed. Oxides of nitrogen emission indices with afterburning were less than half the value without afterburning. Carbon monoxide and hydrocarbon emissions increased with increasing altitude and decreased with increasing flight speed. Emissions of these species were substantially higher with afterburning than without.

  17. Atomic oxygen between 80 and 120 km: Evidence for a rapid spatial variation in vertical transport near the ionosphere

    NASA Technical Reports Server (NTRS)

    Donahue, T. M.; Wasser, B.

    1977-01-01

    Analysis of OGO-6 OI green line photometer results was carried out for 8 cases when the alignment of the spacecraft was such that local emission rates could be determined below the altitude of maximum emission and down to about 80 km. Results show a variation on a scale of 6 deg to 8 deg in latitude between regions where the emission rate increases rapidly between 90 and 95 km and regions where it increases slowly from 80 km to 95 km. Latitude-altitude maps of iso-emissivity contours and iso-density contours for oxygen concentration are presented. The latter are computed under 3 assumptions concerning excitation mechanisms. Comparisons of the spatial variations of oxygen density with the results of a time dependent theory suggest the regions of strong downward transport alternate on a scale of about 1000 km with regions of weak transport near 90 km. In the first case conversion of O to O3 at night appears to be overwhelmed by downward transport of O.

  18. Tidal winds at mesopause altitudes over Arecibo (18 deg N, 67 deg W), 5-11 April 1989 (AIDA '89)

    NASA Technical Reports Server (NTRS)

    Roper, R. G.; Adams, G. W.; Brosnahan, J. W.

    1993-01-01

    A tidal analysis of the imaging Doppler interferometer scattering point parameter data at upper mesosphere-lower thermosphere altitudes (70-110 km) is presented, on the basis of the procedure developed by Groves (1959), over the interval April 5-11, 1989 at Aercibo as part of Project AIDA. This analysis reveals a typical equatorial easterly circulation, with mean meridional circulation becoming significant only above 96 km. A periodogram analysis shows the diurnal tide to be the most significant feature of the wind field at these altitudes, with zonal amplitudes up to some 50 m/s and meridional amplitudes approximately half this value. The semidiurnal tide is well developed in both zonal and meridional directions only above 96 km. Both 8- and 6-hr components become significant above 100 km, the 6-h component being as strong as both the 24- and 12-h tides at 100 km.

  19. Fire Fighting from High Altitude

    NASA Technical Reports Server (NTRS)

    Cobleigh, Brent; Ambrosia, Vince

    2007-01-01

    A viewgraph presentation on high altitude fire fighting is shown. The topics include: 1) Yellowstone Fire - 1988; 2) 2006 Western States Fire Mission Over-View; 3) AMS-Wildfire Scanner; 4) October 24-25 Mission: Yosemite NP and NF; 5) October 24-25 Mission MODIS Overpass; 6) October 24-25 Mission Highlights; 7) October 28-29 Mission Esperanza Fire, California; 8) Response to the Esperanza Fire in Southern California -- Timeline Oct 27-29 2006; 9) October 28-29 Mission Esperanza Fire Altair Flight Routing; 10) October 28-29 Mission Esperanza Fire Altair Over-Flights; 11) October 28-29 Mission Highlights; 12) Results from the Esperanza Fire Response; 13) 2007 Western States Fire Mission; and 14) Western States UAS Fire Mission 2007

  20. Twisted light transmission over 143 km

    NASA Astrophysics Data System (ADS)

    Krenn, Mario; Handsteiner, Johannes; Fink, Matthias; Fickler, Robert; Ursin, Rupert; Malik, Mehul; Zeilinger, Anton

    2016-11-01

    Spatial modes of light can potentially carry a vast amount of information, making them promising candidates for both classical and quantum communication. However, the distribution of such modes over large distances remains difficult. Intermodal coupling complicates their use with common fibers, whereas free-space transmission is thought to be strongly influenced by atmospheric turbulence. Here, we show the transmission of orbital angular momentum modes of light over a distance of 143 km between two Canary Islands, which is 50× greater than the maximum distance achieved previously. As a demonstration of the transmission quality, we use superpositions of these modes to encode a short message. At the receiver, an artificial neural network is used for distinguishing between the different twisted light superpositions. The algorithm is able to identify different mode superpositions with an accuracy of more than 80% up to the third mode order and decode the transmitted message with an error rate of 8.33%. Using our data, we estimate that the distribution of orbital angular momentum entanglement over more than 100 km of free space is feasible. Moreover, the quality of our free-space link can be further improved by the use of state-of-the-art adaptive optics systems.

  1. Twisted light transmission over 143 km.

    PubMed

    Krenn, Mario; Handsteiner, Johannes; Fink, Matthias; Fickler, Robert; Ursin, Rupert; Malik, Mehul; Zeilinger, Anton

    2016-11-29

    Spatial modes of light can potentially carry a vast amount of information, making them promising candidates for both classical and quantum communication. However, the distribution of such modes over large distances remains difficult. Intermodal coupling complicates their use with common fibers, whereas free-space transmission is thought to be strongly influenced by atmospheric turbulence. Here, we show the transmission of orbital angular momentum modes of light over a distance of 143 km between two Canary Islands, which is 50× greater than the maximum distance achieved previously. As a demonstration of the transmission quality, we use superpositions of these modes to encode a short message. At the receiver, an artificial neural network is used for distinguishing between the different twisted light superpositions. The algorithm is able to identify different mode superpositions with an accuracy of more than 80% up to the third mode order and decode the transmitted message with an error rate of 8.33%. Using our data, we estimate that the distribution of orbital angular momentum entanglement over more than 100 km of free space is feasible. Moreover, the quality of our free-space link can be further improved by the use of state-of-the-art adaptive optics systems.

  2. Predicted optical performance of the high-altitude balloon experiment (HABE) telescope in an adverse thermal environment

    SciTech Connect

    Akau, R.L.; Givler, R.C.; Eastman, D.R.

    1994-04-01

    The High-Altitude Balloon Experiment (HABE) telescope was designed to operate at an ambient temperature of {minus}55 C and an altitude of 26 km, using a precooled primary mirror. Although at this altitude the air density is only 1.4 percent of the value at sea level, the temperature gradients within the telescope are high enough to deform the optical wavefront. This problem is considerably lessened by precooling the primary mirror to {minus}35 C. This paper describes the application of several codes to determine the range of wavefront deformation during a mission.

  3. Ozone profile intercomparison based on simultaneous observations between 20 and 40 km

    NASA Technical Reports Server (NTRS)

    Aimedieu, P.; Krueger, A. J.; Robbins, D. E.; Simon, P. C.

    1983-01-01

    The vertical distribution of stratospheric ozone has been simultaneously measured by means of five different instruments carried on the same balloon payload. The launches were performed from Gap during the intercomparison campaign conducted in June 1981 in southern France. Data obtained between altitudes of 20 and 40 km are compared and discussed. Vertical profiles deduced from Electrochemical Concentration Cell sondes launched from the same location by small balloons and from short Umkehr measurements made at Mt Chiran (France) are also included in this comparison. Systematic differences of the order of 20 percent between ozone profiles deduced from solar u.v. absorption and in situ techniques are found.

  4. Compilation of atmospheric gas concentration profiles from 0 to 50 km

    NASA Technical Reports Server (NTRS)

    Smith, M. A. H.

    1982-01-01

    A set of 52 atmospheric gas concentration profiles between 0 and 50 km was compiled as a convenient reference data set for calculation of atmospheric infrared absorption or emission signals and for initialization of iterative procedures for retrieval of gas concentrations from measured data. The distributions of volume mixing ratio as a function of altitude generally correspond to typical diurnally averaged, seasonally averaged Northern Hemisphere midlatitude gas concentration profiles. Profiles are given for all gases included in current infrared atmospheric absorption line parameter compilations, and for a number of additional important trace gases.

  5. Ionosphere variations at 700 km altitude observed by the DEMETER satellite during the 29 March 2006 solar eclipse

    NASA Astrophysics Data System (ADS)

    Wang, X.; Berthelier, J. J.; Lebreton, J. P.

    2010-11-01

    We present an experimental and modeling study of the effects of the 29 March 2006 solar eclipse in the topside ionosphere. Measurements of the densities and temperatures of the thermal electrons and ions were provided by instruments aboard the Centre National d'Etudes Spatiales microsatellite DEMETER, which flew over Europe and Africa near the time of maximum solar obscuration. Data from several orbits, either on the same day or on days encompassing the eclipse day, were available to determine a reference state of the ionosphere along the orbit in absence of eclipse. The comparison between this latter and the actual observations along the eclipse orbit reveal a clear thermal effect with a fast drop of about 200 K of the electron and ion temperatures that follows the variations of the solar UV flux in the F region of the ionosphere conjugate to the satellite position. The plasma density decreases by about 30% but with a significant delay and is better correlated with the solar UV flux averaged over the previous 1 to 2 h in the conjugate F region. This delayed and prolonged decrease of density induces an increase of the electron temperature to be higher than the reference ionosphere. We have also performed a modeling of the ionosphere using the SAMI2 code, after having introduced adequate modifications to reproduce fairly realistic eclipse conditions. Applied to the DEMETER conditions of observation, the model reproduces the observations very well. This work shows that the plasma temperature responds very quickly along the magnetic field lines to the variations of the energy available from the photoelectrons while the plasma density variations are controlled by more complex and slower transport processes.

  6. Wave analysis in the atmosphere of Venus below 100-km altitude, simulated by the LMD Venus GCM

    NASA Astrophysics Data System (ADS)

    Lebonnois, Sébastien; Sugimoto, Norihiko; Gilli, Gabriella

    2016-11-01

    A new simulation of Venus atmospheric circulation obtained with the LMD Venus GCM is described and the simulated wave activity is analyzed. Agreement with observed features of the temperature structure, static stability and zonal wind field is good, such as the presence of a cold polar collar, diurnal and semi-diurnal tides. At the resolution used (96 longitudes × 96 latitudes), a fully developed superrotation is obtained both when the simulation is initialized from rest and from an atmosphere already in superrotation, though winds are still weak below the clouds (roughly half the observed values). The atmospheric waves play a crucial role in the angular momentum budget of the Venus's atmospheric circulation. In the upper cloud, the vertical angular momentum is transported by the diurnal and semi-diurnal tides. Above the cloud base (approximately 1 bar), equatorward transport of angular momentum is done by polar barotropic and mid- to high-latitude baroclinic waves present in the cloud region, with frequencies between 5 and 20 cycles per Venus day (periods between 6 and 23 Earth days). In the middle cloud, just above the convective layer, a Kelvin type wave (period around 7.3 Ed) is present at the equator, as well as a low-latitude Rossby-gravity type wave (period around 16 Ed). Below the clouds, large-scale mid- to high-latitude gravity waves develop and play a significant role in the angular momentum balance.

  7. An innovative rotational Raman lidar to measure the temperature profile from the surface to 30 km altitude

    NASA Astrophysics Data System (ADS)

    Hauchecorne, Alain; Keckhut, Philippe; Mariscal, Jean-François; d'Almeida, Eric; Dahoo, Pierre-Richard; Porteneuve, Jacques

    2016-06-01

    A concept of innovative rotational Raman lidar with daylight measurement capability is proposed to measure the vertical profile of temperature from the ground to the middle stratosphere. The optical filtering is made using a Fabry-Pérot Interferometer with line spacing equal to the line spacing of the Raman spectrum. The detection is made using a linear PMT array operated in photon counting mode. We plan to build a prototype and to test it at the Haute-Provence Observatory lidar facility. to achieve a time resolution permitting the observation of small-scale atmospheric processes playing a role in the troposphere-stratosphere interaction as gravity waves. If successful, this project will open the possibility to consider a Raman space lidar for the global observation of atmospheric temperature profiles.

  8. Processing techniques for global land 1-km AVHRR data

    USGS Publications Warehouse

    Eidenshink, Jeffery C.; Steinwand, Daniel R.; Wivell, Charles E.; Hollaren, Douglas M.; Meyer, David

    1993-01-01

    The U.S. Geological Survey's (USGS) Earth Resources Observation Systems (EROS) Data Center (EDC) in cooperation with several international science organizations has developed techniques for processing daily Advanced Very High Resolution Radiometer (AVHRR) 1-km data of the entire global land surface. These techniques include orbital stitching, geometric rectification, radiometric calibration, and atmospheric correction. An orbital stitching algorithm was developed to combine consecutive observations acquired along an orbit by ground receiving stations into contiguous half-orbital segments. The geometric rectification process uses an AVHRR satellite model that contains modules for forward mapping, forward terrain correction, and inverse mapping with terrain correction. The correction is accomplished by using the hydrologic features coastlines and lakes from the Digital Chart of the World. These features are rasterized into the satellite projection and are matched to the AVHRR imagery using binary edge correlation techniques. The resulting coefficients are related to six attitude correction parameters: roll, roll rate, pitch, pitch rate, yaw, and altitude. The image can then be precision corrected to a variety of map projections and user-selected image frames. Because the AVHRR lacks onboard calibration for the optical wavelengths, a series of time-variant calibration coefficients derived from vicarious calibration methods and are used to model the degradation profile of the instruments. Reducing atmospheric effects on AVHRR data is important. A method has been develop that will remove the effects of molecular scattering and absorption from clear sky observations, using climatological measurements of ozone. Other methods to remove the effects of water vapor and aerosols are being investigated.

  9. 45-km horizontal-path optical link experiment

    NASA Astrophysics Data System (ADS)

    Biswas, Abhijit; Ceniceros, Juan M.; Novak, Matthew J.; Jeganathan, Muthu; Portillo, Angel; Erickson, David M.; de Pew, Jon; Sanii, B.; Lesh, James R.

    1999-04-01

    Mountain-top to mountain-top optical link experiments have been initiated at JPL, in order to perform a systems level evaluation of optical communications. Progress made so far is reported. The NASA, JPL developed optical communications demonstrator (OCD) is used to transmit a laser signal from Strawberry Peak (SP), located in the San Bernadino mountains of California. This laser beam is received by a 0.6 m aperture telescope at JPL's Table Mountain Facility (TMF), located in Wrightwood, California. The optical link is bi-directional with the TMF telescope transmitting a continuous 4-wave (cw) 780 nm beacon and the OCD sending back an 840 nm, 100 - 500 Mbps pseudo noise (PN) modulated, laser beam. The optical link path is at an average altitude of 2 Km above sea level, covers a range of 46.8 Km and provides an atmospheric channel equivalent to approximately 4 air masses. Average received power measured at either end fall well within the uncertainties predicted by link analysis. The reduction in normalized intensity variance ((sigma) I2) for the 4- beam beacon, compared to each individual beam, at SP, was from approximately 0.68 to 0.22. With some allowance for intra-beam mis-alignment, this is consistent with incoherent averaging. The (sigma) I2 measured at TMF approximately 0.43 plus or minus 0.22 exceeded the expected aperture averaged value of less than 0.1, probably because of beam wander. The focused spot sizes of approximately 162 plus or minus 6 micrometer at the TMF Coude and approximately 64 plus or minus 3 micrometer on the OCD compare to the predicted size range of 52 - 172 micrometer and 57 - 93 micrometer, respectively. This is consistent with 4 - 5 arcsec of atmospheric 'seeing.' The preliminary evaluation of OCD's fine tracking indicates that the uncompensated tracking error is approximately 3.3 (mu) rad compared to approximately 1.7 (mu) rad observed in the laboratory. Fine tracking performance was intermittent, primarily due to beacon fades on the

  10. High Altitude Illnesses in Hawai‘i

    PubMed Central

    2014-01-01

    High Altitude Headache (HAH), Acute Mountain Sickness (AMS), and High Altitude Cerebral Edema (HACE) are all high altitude related illnesses in order of severity from the mildly symptomatic to the potentially life-threatening. High altitude illnesses occur when travelers ascend to high altitudes too rapidly, which does not allow enough time for the body to adjust. Slow graded ascent to the desired altitude and termination of ascent if AMS symptoms present are keys to illness prevention. Early recognition and rapid intervention of AMS can halt progression to HACE. Pharmacologic prophylaxis with acetazolamide is a proven method of prevention and treatment of high altitude illness. If prevention fails then treatment modalities include supplemental oxygen, supportive therapy, hyperbaric treatment, and dexamethasone. Given the multitude of visitors to the mountains of Hawai‘i, high altitude illness will continue to persist as a prevalent local condition. This paper will emphasize the prevention and early diagnosis of AMS so that the illness does not progress to HACE. PMID:25478293

  11. 77 FR 3091 - IFR Altitudes; Miscellaneous Amendments

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-23

    ... Altitudes and Changeover Points Amendment 498 Effective Date February 9, 2012 From To MEA Sec. 95.10 Amber... From To MEA MAA Sec. 95.3000 Low Altitude RNAV Routes Sec. 95.3223 RNAV Route T223 Is Amended To Read... FIX Amott, AK FIX 18000 45000 Total Changeover From/To distance distance Point from Track angle...

  12. 76 FR 59890 - IFR Altitudes; Miscellaneous Amendments

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-28

    ... Altitudes and Changeover Points From To MEA MAA Sec. 95.4000 High Altitude RNAV Routes Sec. 95.4037 RNAV Route Q37 Is Added to Read FORT STOCKTON, TX VORTAC CAVRN, TX FIX *25000 45000 *18000--GNSS MEA *DME/DME/IRU MEA CAVRN, TX FIX YORUB, NM FIX *25000 45000 *18000--GNSS MEA *DME/DME/IRU MEA YORUB, NM FIX...

  13. Density Altitude Maps of Iran and Iraq

    DTIC Science & Technology

    1991-05-01

    standard, DA is lower than PA. DA can also be expressed as the altitude in the ICAO standard atmosphere at which a given density occurs. The maps...produced in this study show the altitude in the ICAO standard atmosphere at which surface density occurs.

  14. Predicting km-scale shear zone formation

    NASA Astrophysics Data System (ADS)

    Gerbi, Christopher; Culshaw, Nicholas; Shulman, Deborah; Foley, Maura; Marsh, Jeffrey

    2015-04-01

    Because km-scale shear zones play a first-order role in lithospheric kinematics, accurate conceptual and numerical models of orogenic development require predicting when and where they form. Although a strain-based algorithm in the upper crust for weakening due to faulting appears to succeed (e.g., Koons et al., 2010, doi:10.1029/2009TC002463), a comparable general rule for the viscous crust remains unestablished. Here we consider two aspects of the geological argument for a similar algorithm in the viscous regime, namely (1) whether predicting km-scale shear zone development based on a single parameter (such as strain or shear heating) is reasonable; and (2) whether lithologic variability inherent in most orogenic systems precludes a simple predictive rule. A review of tectonically significant shear zones worldwide and more detailed investigations in the Central Gneiss belt of the Ontario segment of the Grenville Province reveals that most km-scale shear zones occur at lithological boundaries and involve mass transfer, but have fairly little else in common. As examples, the relatively flat-lying Twelve Mile Bay shear zone in the western Central Gneiss belt bounds the Parry Sound domain and is likely the product of both localized anatexis and later retrograde hydration with attendant metamorphism. Moderately dipping shear zones in granitoids of the Grenville Front Tectonic Zone apparently resulted from cooperation among several complementary microstructural processes, such as grain size reduction, enhanced diffusion, and a small degree of metamorphic reaction. Localization into shear zones requires the operation of some spatially restricted processes such as stress concentration, metamorphism/fluid access, textural evolution, and thermal perturbation. All of these could be due in part to strain, but not necessarily linearly related to strain. Stress concentrations, such as those that form at rheological boundaries, may be sufficient to nucleate high strain

  15. Characteristics and Drivers of High-Altitude Ladybird Flight: Insights from Vertical-Looking Entomological Radar

    PubMed Central

    Jeffries, Daniel L.; Chapman, Jason; Roy, Helen E.; Humphries, Stuart; Harrington, Richard; Brown, Peter M. J.; Handley, Lori-J. Lawson

    2013-01-01

    Understanding the characteristics and drivers of dispersal is crucial for predicting population dynamics, particularly in range-shifting species. Studying long-distance dispersal in insects is challenging, but recent advances in entomological radar offer unique insights. We analysed 10 years of radar data collected at Rothamsted Research, U.K., to investigate characteristics (altitude, speed, seasonal and annual trends) and drivers (aphid abundance, air temperature, wind speed and rainfall) of high-altitude flight of the two most abundant U.K. ladybird species (native Coccinella septempunctata and invasive Harmonia axyridis). These species cannot be distinguished in the radar data since their reflectivity signals overlap, and they were therefore analysed together. However, their signals do not overlap with other, abundant insects so we are confident they constitute the overwhelming majority of the analysed data. The target species were detected up to ∼1100 m above ground level, where displacement speeds of up to ∼60 km/h were recorded, however most ladybirds were found between ∼150 and 500 m, and had a mean displacement of 30 km/h. Average flight time was estimated, using tethered flight experiments, to be 36.5 minutes, but flights of up to two hours were observed. Ladybirds are therefore potentially able to travel 18 km in a “typical” high-altitude flight, but up to 120 km if flying at higher altitudes, indicating a high capacity for long-distance dispersal. There were strong seasonal trends in ladybird abundance, with peaks corresponding to the highest temperatures of mid-summer, and warm air temperature was the key driver of ladybird flight. Climatic warming may therefore increase the potential for long-distance dispersal in these species. Low aphid abundance was a second significant factor, highlighting the important role of aphid population dynamics in ladybird dispersal. This research illustrates the utility of radar for studying high-altitude

  16. Feasibility study for rocket ozone measurements in the 50 to 80 km region using a chemiluminescent technique

    NASA Technical Reports Server (NTRS)

    Goodman, P.

    1973-01-01

    A study has been conducted to determine the feasibility of increasing sensitivity for ozone detection. The detection technique employed is the chemiluminescent reaction of ozone with a rhodamine-B impregnated disk. Previously achieved sensitivities are required to be increased by a factor of about 20 to permit measurements at altitudes of 80 km. Sensitivity was increased by using a more sensitive photomultiplier tube, by increasing the gas velocity past the disk, by different disk preparation techniques, and by using reflective coatings in the disk chamber and on the uncoated side of the glass disk. Reflective coatings provided the largest sensitivity increase. The sum of all these changes was a sensitivity increased by an estimated factor of 70, more than sufficient to permit measurement of ambient ozone concentrations at altitudes of 80 km.

  17. Developmental functional adaptation to high altitude: review.

    PubMed

    Frisancho, A Roberto

    2013-01-01

    Various approaches have been used to understand the origins of the functional traits that characterize the Andean high-altitude native. Based on the conceptual framework of developmental functional adaptation which postulates that environmental influences during the period of growth and development have long lasting effects that may be expressed during adulthood, we initiated a series of studies addressed at determining the pattern of physical growth and the contribution of growth and development to the attainment of full functional adaptation to high-altitude of low and high altitude natives living under rural and urban conditions. Current research indicate that: (a) the pattern of growth at high altitude due to limited nutritional resources, physical growth in body size is delayed but growth in lung volumes is accelerated because of hypoxic stress); (b) low-altitude male and female urban natives can attain a full functional adaptation to high altitude by exposure to high-altitude hypoxia during the period of growth and development; (c) both experimental studies on animals and comparative human studies indicate that exposure to high altitude during the period of growth and development results in the attainment of a large residual lung volume; (d) this developmentally acquired enlarged residual lung volume and its associated increase in alveolar area when combined with the increased tissue capillarization and moderate increase in red blood cells and hemoglobin concentration contributes to the successful functional adaptation of the Andean high-altitude native to hypoxia; and (e) any specific genetic traits that are related to the successful functional adaptation of Andean high-altitude natives have yet to be identified.

  18. Diving at altitude: from definition to practice.

    PubMed

    Egi, S Murat; Pieri, Massimo; Marroni, Alessandro

    2014-01-01

    Diving above sea level has different motivations for recreational, military, commercial and scientific activities. Despite the apparently wide practice of inland diving, there are three major discrepancies about diving at altitude: threshold elevation that requires changes in sea level procedures; upper altitude limit of the applicability of these modifications; and independent validation of altitude adaptation methods of decompression algorithms. The first problem is solved by converting the normal fluctuation in barometric pressure to an altitude equivalent. Based on the barometric variations recorded from a meteorological center, it is possible to suggest 600 meters as a threshold for classifying a dive as an "altitude" dive. The second problem is solved by proposing the threshold altitude of aviation (2,400 meters) to classify "high" altitude dives. The DAN (Divers Alert Network) Europe diving database (DB) is analyzed to solve the third problem. The database consists of 65,050 dives collected from different dive computers. A total of 1,467 dives were found to be classified as altitude dives. However, by checking the elevation according to the logged geographical coordinates, 1,284 dives were disqualified because the altitude setting had been used as a conservative setting by the dive computer despite the fact that the dive was made at sea level. Furthermore, according to the description put forward in this manuscript, 72 dives were disqualified because the surface level elevation is lower than 600 meters. The number of field data (111 dives) is still very low to use for the validation of any particular method of altitude adaptation concerning decompression algorithms.

  19. Sleep at high altitude: guesses and facts.

    PubMed

    Bloch, Konrad E; Buenzli, Jana C; Latshang, Tsogyal D; Ulrich, Silvia

    2015-12-15

    Lowlanders commonly report a poor sleep quality during the first few nights after arriving at high altitude. Polysomnographic studies reveal that reductions in slow wave sleep are the most consistent altitude-induced changes in sleep structure identified by visual scoring. Quantitative spectral analyses of the sleep electroencephalogram have confirmed an altitude-related reduction in the low-frequency power (0.8-4.6 Hz). Although some studies suggest an increase in arousals from sleep at high altitude, this is not a consistent finding. Whether sleep instability at high altitude is triggered by periodic breathing or vice versa is still uncertain. Overnight changes in slow wave-derived encephalographic measures of neuronal synchronization in healthy subjects were less pronounced at moderately high (2,590 m) compared with low altitude (490 m), and this was associated with a decline in sleep-related memory consolidation. Correspondingly, exacerbation of breathing and sleep disturbances experienced by lowlanders with obstructive sleep apnea during a stay at 2,590 m was associated with poor performance in driving simulator tests. These findings suggest that altitude-related alterations in sleep may adversely affect daytime performance. Despite recent advances in our understanding of sleep at altitude, further research is required to better establish the role of gender and age in alterations of sleep at different altitudes, to determine the influence of acclimatization and of altitude-related illness, and to uncover the characteristics of sleep in highlanders that may serve as a study paradigm of sleep in patients exposed to chronic hypoxia due to cardiorespiratory disease.

  20. Jupiter's High-Altitude Clouds

    NASA Technical Reports Server (NTRS)

    2007-01-01

    The New Horizons Multispectral Visible Imaging Camera (MVIC) snapped this incredibly detailed picture of Jupiter's high-altitude clouds starting at 06:00 Universal Time on February 28, 2007, when the spacecraft was only 2.3 million kilometers (1.4 million miles) from the solar system's largest planet. Features as small as 50 kilometers (30 miles) are visible. The image was taken through a narrow filter centered on a methane absorption band near 890 nanometers, a considerably redder wavelength than what the eye can see. Images taken through this filter preferentially pick out clouds that are relatively high in the sky of this gas giant planet because sunlight at the wavelengths transmitted by the filter is completely absorbed by the methane gas that permeates Jupiter's atmosphere before it can reach the lower clouds.

    The image reveals a range of diverse features. The south pole is capped with a haze of small particles probably created by the precipitation of charged particles into the polar regions during auroral activity. Just north of the cap is a well-formed anticyclonic vortex with rising white thunderheads at its core. Slightly north of the vortex are the tendrils of some rather disorganized storms and more pinpoint-like thunderheads. The dark 'measles' that appear a bit farther north are actually cloud-free regions where light is completely absorbed by the methane gas and essentially disappears from view. The wind action considerably picks up in the equatorial regions where giant plumes are stretched into a long wave pattern. Proceeding north of the equator, cirrus-like clouds are shredded by winds reaching speeds of up to 400 miles per hour, and more pinpoint-like thunderheads are visible. Although some of the famous belt and zone structure of Jupiter's atmosphere is washed out when viewed at this wavelength, the relatively thin North Temperate Belt shows up quite nicely, as does a series of waves just north of the belt. The north polar region of

  1. A parametric study of dissociation and ionization models at 12 km/sec

    NASA Technical Reports Server (NTRS)

    Mitcheltree, R. A.

    1991-01-01

    Thermochemical nonequilibrium-solution dependence on available models for the chemical reaction rates is examined. Solutions from the Kang and Dunn (1973) reaction-rate set, the Park rate set of 1987, and the Park rate set of 1991 are compared. The blunt-nosed, axisymmetric geometry considered is a 60-deg sphere cone with nose radius of 1.07 m and cicular aft skirt. The nonequilibrium test case is 12 km/sec entry into the earth's atmosphere at 80 km altitude. The model variations are implemented into the Langley aerothermodynamics upwind relaxation algorithm code. While variations in the reaction rates have no effect on the surface pressure distribution and little effect on the convective heating, the effect on degree of ionization and radiative heating can be a factor of three.

  2. Cerebrovascular reactivity is increased with acclimatization to 3,454 m altitude.

    PubMed

    Flück, Daniela; Siebenmann, Christoph; Keiser, Stefanie; Cathomen, Adrian; Lundby, Carsten

    2015-08-01

    Controversy exists regarding the effect of high-altitude exposure on cerebrovascular CO2 reactivity (CVR). Confounding factors in previous studies include the use of different experimental approaches, ascent profiles, duration and severity of exposure and plausibly environmental factors associated with altitude exposure. One aim of the present study was to determine CVR throughout acclimatization to high altitude when controlling for these. Middle cerebral artery mean velocity (MCAv mean) CVR was assessed during hyperventilation (hypocapnia) and CO2 administration (hypercapnia) with background normoxia (sea level (SL)) and hypoxia (3,454 m) in nine healthy volunteers (26 ± 4 years (mean ± s.d.)) at SL, and after 30 minutes (HA0), 3 (HA3) and 22 (HA22) days of high-altitude (3,454 m) exposure. At altitude, ventilation was increased whereas MCAv mean was not altered. Hypercapnic CVR was decreased at HA0 (1.16% ± 0.16%/mm Hg, mean ± s.e.m.), whereas both hyper- and hypocapnic CVR were increased at HA3 (3.13% ± 0.18% and 2.96% ± 0.10%/mm Hg) and HA22 (3.32% ± 0.12% and 3.24% ± 0.14%/mm Hg) compared with SL (1.98% ± 0.22% and 2.38% ± 0.10%/mm Hg; P < 0.01) regardless of background oxygenation. Cerebrovascular conductance (MCAv mean/mean arterial pressure) CVR was determined to account for blood pressure changes and revealed an attenuated response. Collectively our results show that hypocapnic and hypercapnic CVR are both elevated with acclimatization to high altitude.

  3. Cerebrovascular reactivity is increased with acclimatization to 3,454 m altitude

    PubMed Central

    Flück, Daniela; Siebenmann, Christoph; Keiser, Stefanie; Cathomen, Adrian; Lundby, Carsten

    2015-01-01

    Controversy exists regarding the effect of high-altitude exposure on cerebrovascular CO2 reactivity (CVR). Confounding factors in previous studies include the use of different experimental approaches, ascent profiles, duration and severity of exposure and plausibly environmental factors associated with altitude exposure. One aim of the present study was to determine CVR throughout acclimatization to high altitude when controlling for these. Middle cerebral artery mean velocity (MCAvmean) CVR was assessed during hyperventilation (hypocapnia) and CO2 administration (hypercapnia) with background normoxia (sea level (SL)) and hypoxia (3,454 m) in nine healthy volunteers (26±4 years (mean±s.d.)) at SL, and after 30 minutes (HA0), 3 (HA3) and 22 (HA22) days of high-altitude (3,454 m) exposure. At altitude, ventilation was increased whereas MCAvmean was not altered. Hypercapnic CVR was decreased at HA0 (1.16%±0.16%/mm Hg, mean±s.e.m.), whereas both hyper- and hypocapnic CVR were increased at HA3 (3.13%±0.18% and 2.96%±0.10%/mm Hg) and HA22 (3.32%±0.12% and 3.24%±0.14%/mm Hg) compared with SL (1.98%±0.22% and 2.38%±0.10%/mm Hg; P<0.01) regardless of background oxygenation. Cerebrovascular conductance (MCAvmean/mean arterial pressure) CVR was determined to account for blood pressure changes and revealed an attenuated response. Collectively our results show that hypocapnic and hypercapnic CVR are both elevated with acclimatization to high altitude. PMID:25806704

  4. Application of Multilayer Feedforward Neural Networks to Precipitation Cell-Top Altitude Estimation

    NASA Technical Reports Server (NTRS)

    Spina, Michelle S.; Schwartz, Michael J.; Staelin, David H.; Gasiewski, Albin J.

    1998-01-01

    The use of passive 118-GHz O2 observations of rain cells for precipitation cell-top altitude estimation is demonstrated by using a multilayer feed forward neural network retrieval system. Rain cell observations at 118 GHz were compared with estimates of the cell-top altitude obtained by optical stereoscopy. The observations were made with 2 4 km horizontal spatial resolution by using the Millimeter-wave Temperature Sounder (MTS) scanning spectrometer aboard the NASA ER-2 research aircraft during the Genesis of Atlantic Lows Experiment (GALE) and the COoperative Huntsville Meteorological EXperiment (COHMEX) in 1986. The neural network estimator applied to MTS spectral differences between clouds, and nearby clear air yielded an rms discrepancy of 1.76 km for a combined cumulus, mature, and dissipating cell set and 1.44 km for the cumulus-only set. An improvement in rms discrepancy to 1.36 km was achieved by including additional MTS information on the absolute atmospheric temperature profile. An incremental method for training neural networks was developed that yielded robust results, despite the use of as few as 56 training spectra. Comparison of these results with a nonlinear statistical estimator shows that superior results can be obtained with a neural network retrieval system. Imagery of estimated cell-top altitudes was created from 118-GHz spectral imagery gathered from CAMEX, September through October 1993, and from cyclone Oliver, February 7, 1993.

  5. High altitude syndromes at intermediate altitudes: a pilot study in the Australian Alps.

    PubMed

    Slaney, Graham; Cook, Angus; Weinstein, Philip

    2013-10-01

    Our hypothesis is that symptoms of high altitude syndromes are detectable even at intermediate altitudes, as commonly encountered under Australian conditions (<2500 m above sea level). High altitude medicine has long recognised several syndromes associated with rapid ascent to altitudes above 2500 m, including high altitude pulmonary oedema (HAPE), high altitude cerebral oedema (HACE) and high altitude flatus expulsion (HAFE). Symptoms of high altitude syndromes are of growing concern because of the global trend toward increasing numbers of tourists and workers exposed to both rapid ascent and sustained physical activity at high altitude. However, in Australia, high altitude medicine has almost no profile because of our relatively low altitudes by international standards. Three factors lead us to believe that altitude sickness in Australia deserves more serious consideration: Australia is subject to rapid growth in alpine recreational industries; altitude sickness is highly variable between individuals, and some people do experience symptoms already at 1500 m; and there is potential for an occupational health and safety issue amongst workers. To test this hypothesis we examined the relationship between any high altitude symptoms and a rapid ascent to an intermediate altitude (1800 m) by undertaking an intervention study in a cohort of eight medical clinic staff, conducted during July of the 2012 (Southern Hemisphere) ski season, using self-reporting questionnaires, at Mansfield (316 m above sea level) and at the Ski Resort of Mt Buller (1800 m), Victoria, Australia. The intervention consisted of ascent by car from Mansfield to Mt Buller (approx. 40 min drive). Participants completed a self-reporting questionnaire including demographic data and information on frequency of normal homeostatic processes (fluid intake and output, food intake and output, symptoms including thirst and headaches, and frequency of passing wind or urine). Data were recorded in hourly periods

  6. Effect of altitude on some blood factors and its stability after leaving the altitude.

    PubMed

    Hematy, Yones; Setorki, Mahbubeh; Razavi, Akram; Doudi, Monir

    2014-09-01

    The underlying mechanisms of altitude training are still a matter of controversial discussion. The aim of this study was to compare the hemoglobin concentration, red blood cell count and volume between normal and high altitude situations and their persistence after returning back from higher altitudes. The study population included male students of Ardal Branch, Islamic Azad University. Twelve apparently healthy individual with high level of physical activity, mean age of 22.6 ± 1.50 years were selected through purposive and available sampling method. In this study, blood samples were collected at different time and altitudes in order to compare the changes of Red Blood Cell (RBC), Mean Cell Hemoglobin (MCH), Mean Corpuscular Hemoglobin Concentration (MCHC) and Mean Cell Volume (MCV). The first blood sampling was conducted at the altitude of 1830 m. The subsequent blood samplings were conducted 48 and 72 h after reaching the altitude of 4000 m and 24, 48 and 72 h after returning back to the altitude of 1830 m. The statistical method used in this study was repeated measurement ANOVA. Red Blood Cell (RBC) changes between onset of climbing to 1830 m and 24, 48 and 2 h after sojourn at 1830 m height (after returning from 4000 m altitude) was significant. Mean Cell Hemoglobin (MCH) showed no significant change in any of the altitudes. MCHC changes between onset of moving toward altitude 1830 meters and 24, 48 and 72 h after sojourn at 1830 m height (after returning from 4000 m altitude) was also significant in addition, MCHC showed a significant difference between 24 h staying at 1830 m altitude with 48 and 72 h staying at 4000 m altitude. Mean Cell Volume (MCV) showed no significant difference between 48 and 72 h staying at 4000 m altitude and also between 24, 48 and 72 h staying at 1830 m altitude; however, there was a significant difference between onset of moving toward 1830 m altitude with 24, 48 and 72 h staying at 1830 m altitude and also 48 and 72 h staying at

  7. Teleportation of entanglement over 143 km.

    PubMed

    Herbst, Thomas; Scheidl, Thomas; Fink, Matthias; Handsteiner, Johannes; Wittmann, Bernhard; Ursin, Rupert; Zeilinger, Anton

    2015-11-17

    As a direct consequence of the no-cloning theorem, the deterministic amplification as in classical communication is impossible for unknown quantum states. This calls for more advanced techniques in a future global quantum network, e.g., for cloud quantum computing. A unique solution is the teleportation of an entangled state, i.e., entanglement swapping, representing the central resource to relay entanglement between distant nodes. Together with entanglement purification and a quantum memory it constitutes a so-called quantum repeater. Since the aforementioned building blocks have been individually demonstrated in laboratory setups only, the applicability of the required technology in real-world scenarios remained to be proven. Here we present a free-space entanglement-swapping experiment between the Canary Islands of La Palma and Tenerife, verifying the presence of quantum entanglement between two previously independent photons separated by 143 km. We obtained an expectation value for the entanglement-witness operator, more than 6 SDs beyond the classical limit. By consecutive generation of the two required photon pairs and space-like separation of the relevant measurement events, we also showed the feasibility of the swapping protocol in a long-distance scenario, where the independence of the nodes is highly demanded. Because our results already allow for efficient implementation of entanglement purification, we anticipate our research to lay the ground for a fully fledged quantum repeater over a realistic high-loss and even turbulent quantum channel.

  8. Relative effects on atmospheric ozone of latitude and altitude of supersonic flight

    NASA Technical Reports Server (NTRS)

    Cunnold, D. M.; Alyea, F. N.; Prinn, R. G.

    1977-01-01

    Three calculations are reported of the potential depletion of ozone by supersonic aircraft. These calculations utilized a two-dimensional model and a three-dimensional photochemical-dynamical model of the atmosphere in which ozone and the dynamical variables of the atmosphere were derived simultaneously. All calculations were based on a continuous atmospheric injection of 1.8 million tons/yr of NO2. Injections of 45 deg N and 20 km, at equilibrium, resulted in a 36% increase in total odd nitrogen between 8 and 38 km and in global ozone depletion of approximately 12%. Injection at 45 deg N and 17 km produced a 27% increase in odd nitrogen, but, because much of this increase occurred below 20 km, the ozone depletion amounted to only 6%. Injection at 10 deg N and 29 km resulted in a 55% increase of odd nitrogen; however, although there was more depletion above 20 km altitude, there was less below that altitude, and the ozone depletion was only 12.5%. In all three calculations, at least half as much ozone depletion occurred in the Southern Hemisphere as in the Northern Hemisphere.

  9. Postnatal cardiopulmonary adaptations to high altitude.

    PubMed

    Huicho, Luis

    2007-09-30

    Postnatal cardiopulmonary adaptations to high altitude constitute a key component of any set of responses developed to face high altitude hypoxia. Such responses are required ultimately to meet the energy demands necessary for adequate functioning at cell and organism level. After a brief insight on general and cardiopulmonary comparative studies in growing and adult organisms, differences and possible explanations for varying cardiopulmonary pathology, pulmonary artery hypertension, persistent right ventricular predominance and subacute high altitude pulmonary hypertension in different populations of children living at high altitude are discussed. Potential long-term implications of early chronic hypoxic exposure on later diseases are also presented. It is hoped that this review will help the practicing physician working at high altitude to make informed decisions concerning individual pediatric patients, specifically with regard to diagnosis and management of altitude-related cardiopulmonary pathology. Finally, plausibility and the knowledge-base of public health interventions to reduce the risks posed by suboptimal or inadequate postnatal cardiopulmonary responses to high altitude are discussed.

  10. [Sildenafil and exercise performance at altitude].

    PubMed

    Peidro, Roberto M

    2015-01-01

    Barometric pressure and partial oxygen pressure decrease with increasing altitude. Hypobaric hypoxia produced is responsible for altitude-related diseases and it can cause severe decrements in exercise performance. The physiological adaptations to the altitude are multiple and they contribute to alter different athletic qualities. The VO2 worsening could be associated to increased pulmonary vascular resistance and nitric oxide diffusion alteration. Performance impairments at altitude can also be accentuated by hypoxia-induced elevations in pulmonary arterial pressure. Clinical studies have demonstrated the beneficial effects of sildenafil on the treatment of pulmonary hypertension. These effects have led to suggest that its indication for competitions at altitude might improve athletic performance. The investigations demonstrate different results depending on the altitude level and times and intensities of exercise. Some studies show performance improvements, although not in all participants. Individual responses vary widely between different athletes. This presentation examines the effects of altitude on exercise capacity and shows studies about the use of sildenafil to improve sport performance. This text also discusses the possible side effects and implications for the use of sildenafil in athletes, indication that is not the basic one of the drug. The physicians must know in each athlete the individual sildenafil side effects that could arise and that would influence negatively on health and performance.

  11. Carbon monoxide studies at high altitude.

    PubMed

    McGrath, J J

    1988-01-01

    In high altitude areas, ambient carbon monoxide (CO) concentrations are rising because of the increasing number of new residents and tourists, and their concomitant use of motor vehicles and heating appliances. There are, however, comparatively few studies of the acute or chronic physiological effects that may be caused by inhaling CO at high altitude. There are data supporting the concept that the effects of breathing CO at high altitude are additive, and data suggesting that the effects may be more than additive. Visual sensitivity and flicker fusion frequency are reduced in humans inhaling CO at high altitude. One provocative study suggests that the increase in coronary capillarity seen with chronic altitude exposure may be blocked by CO. We exposed male, laboratory rats for 6 weeks to 100 ppm CO, 4676 m (15,000 ft) simulated high altitude (SHA), and CO at SHA. SHA increase hematocrit ratio (Hct) and right ventricle weight, but decreased body weight. CO increased Hct and left ventricle weight. Our results indicate that 100 ppm CO does not exacerbate the effects produced by exposure to 4676 m altitude.

  12. High Altitude Launch for a Practical SSTO

    NASA Technical Reports Server (NTRS)

    Landis, Geoffrey A.; Denis, Vincent

    2003-01-01

    Existing engineering materials allow the construction of towers to heights of many kilometers. Orbital launch from a high altitude has significant advantages over sea-level launch due to the reduced atmospheric pressure, resulting in lower atmospheric drag on the vehicle and allowing higher rocket engine performance. High-altitude launch sites are particularly advantageous for single-stage to orbit (SSTO) vehicles, where the payload is typically 2 percent of the initial launch mass. An earlier paper enumerated some of the advantages of high altitude launch of SSTO vehicles. In this paper, we calculate launch trajectories for a candidate SSTO vehicle, and calculate the advantage of launch at launch altitudes 5 to 25 kilometer altitudes above sea level. The performance increase can be directly translated into increased payload capability to orbit, ranging from 5 to 20 percent increase in the mass to orbit. For a candidate vehicle with an initial payload fraction of 2 percent of gross lift-off weight, this corresponds to 31 percent increase in payload (for 5-kilometer launch altitude) to 122 percent additional payload (for 25-kilometer launch altitude).

  13. Performance of Portable Ventilators at Altitude

    DTIC Science & Technology

    2015-03-30

    Deploying ventilators that can maintain a consistent tidal volume ( VT ) delivery at various altitudes is imperative for lung protection when...and adult VT (250-750 mL) at 0 and 20 cm H2O positive end expiratory pressure and at inspired oxygen of 0.21 and 1.0. Airway pressure, volume, and...calibrated pneumotachograph connected to a training test lung in an altitude chamber. Set VT and delivered VT and changes in VT at each altitude were

  14. High-Altitude Hydration System

    NASA Technical Reports Server (NTRS)

    Parazynski, Scott E.; Orndoff, Evelyne; Bue, Grant C.; Schaefbauer, Mark E.; Urban, Kase

    2010-01-01

    Three methods are being developed for keeping water from freezing during high-altitude climbs so that mountaineers can remain hydrated. Three strategies have been developed. At the time of this reporting two needed to be tested in the field and one was conceptual. The first method is Passive Thermal Control Using Aerogels. This involves mounting the fluid reservoir of the climber s canteen to an inner layer of clothing for better heat retention. For the field test, bottles were mounted to the inner fleece layer of clothing, and then aerogel insulation was placed on the outside of the bottle, and circumferentially around the drink straw. When climbers need to drink, they can pull up the insulated straw from underneath the down suit, take a sip, and then put it back into the relative warmth of the suit. For the field test, a data logger assessed the temperatures of the water reservoir, as well as near the tip of the drink straw. The second method is Passive Thermal Control with Copper-Shielded Drink Straw and Aerogels, also mounted to inner layers of clothing for better heat retention. Braided wire emanates from the inside of the fleece jacket layer, and continues up and around the drink straw in order to use body heat to keep the system-critical drink straw warm enough to keep water in the liquid state. For the field test, a data logger will be used to compare this with the above concept. The third, and still conceptual, method is Active Thermal Control with Microcontroller. If the above methods do not work, microcontrollers and tape heaters have been identified that could keep the drink straw warm even under extremely cold conditions. Power requirements are not yet determined because the thermal environment inside the down suit relative to the external environment has not been established. A data logger will be used to track both the external and internal temperatures of the suit on a summit day.

  15. Daytime ClO over McMurdo in September 1987: Altitude profile retrieval accuracy

    NASA Technical Reports Server (NTRS)

    Barrett, J.; Solomon, P.; Jaramillo, M.; Dezafra, R. L.; Parrish, A.; Emmons, L.

    1988-01-01

    During the 1987 National Ozone Expedition, mm-wave emission line spectra of the 278.6 GHz rotational stratospheric ClO were observed at McMurdo Station, Antarctica. The results confirm the 1986 discovery of a lower stratospheric layer with approximately 100 times the normal amount of ClO; the 1987 observations, made with a spectrometer bandwidth twice that used in 1986, make possible a more accurate retrieval of the altitude profile of the low altitude component of stratospheric ClO from the pressure broadened line shape, down to approximately 16 km. The accuracy of the altitude profile retrievals is discussed, using the daytime (09:30 to 19:30, local time) data from 20 to 24 September, 1987 as an example. The signal strength averaged over this daytime period is approx. 85 percent of the midday peak value. The rate of ozone depletion implied by the observed ClO densities is also discussed.

  16. Very Early 3-13 micron Spectral Development of V1187 Sco (Nova Scorpii 2004 #2)

    NASA Astrophysics Data System (ADS)

    Russell, R. W.; Lynch, D. K.; Kim, D. L.; Perry, R. B.; Geballe, T. R.; Fisher, R. S.

    2004-12-01

    Moderate spectral resolution (30-200) data were obtained with the Aerospace Broadband Array Spectrograph System (BASS) on the NASA IRTF 3 m and with Michelle on Gemini North of V1187 Scorpii during the week following maximum light ( Aug. 3UT, 2004). We present a time-series of 3-13 micron spectra from Aug. 5 to Aug. 11 UT, 2004. The spectra initially exhibited the expected gray body continuum at about 1500 K, which cooled from night to night, followed by the appearance of numerous hydrogen lines, of which Humphreys alpha was one of the most prominent. The hydrogen lines increased in intensity until about Aug 8 UT, and then began a gradual decline. The higher spectral resolution Michelle data on Aug. 11 UT showed that essentially all of the features seen were hydrogen lines. The dependence with time of the line intensities will be shown and discussed. These data complement the spectroscopy presented in poster sessions by Lynch et al. (.8-5 microns with a variety of instruments and telescopes) and Woodward et al. (Spitzer data from Sept 28 UT, 2004) at this meeting. Thus, the observations show classical nova development typical of a very fast nova (t2 about 8 or 9 days) in the infrared with unprecedented thermal spectral coverage this close to maximum light. The unique time series began serendipitously using BASS at the IRTF, and included collaborative observations by the IRTF, UKIRT, Gemini and Keck. The series was crowned by the Spitzer spectrum cited above, accompanied by near-simultaneous observations from the IRTF and Gemini. We are grateful to Alan Tokunaga of the IRTF for granting us telescope time on short notice to extend our BASS coverage and to Jean Rene Roy for granting us time on Gemini. This work was supported at The Aerospace Corporation by the Independent Research and Development program.

  17. Temperature minima in the average thermal structure of the middle mesosphere (70 - 80 km) from analysis of 40- to 92-km SME global temperature profiles

    NASA Technical Reports Server (NTRS)

    Clancy, R. Todd; Rusch, David W.; Callan, Michael T.

    1994-01-01

    Global temperatures have been derived for the upper stratosphere and mesosphere from analysis of Solar Mesosphere Explorer (SME) limb radiance profiles. The SME temperature represent fixed local time observations at 1400 - 1500 LT, with partial zonal coverage of 3 - 5 longitudes per day over the 1982-1986 period. These new SME temperatures are compared to the COSPAR International Ionosphere Reference Atmosphere 86 (CIRA 86) climatology (Fleming et al., 1990) as well as stratospheric and mesospheric sounder (SAMS); Barnett and Corney, 1984), National Meteorological Center (NMC); (Gelman et al., 1986), and individual lidar and rocket observations. Significant areas of disagreement between the SME and CIRA 86 mesospheric temperatures are 10 K warmer SME temperatures at altitudes above 80 km. The 1981-1982 SAMS temperatures are in much closer agreement with the SME temperatures between 40 and 75 km. Although much of the SME-CIRA 86 disagreement probably stems from the poor vertical resolution of the observations comprising the CIRA 86 modelm, some portion of the differences may reflect 5- to 10-year temporal variations in mesospheric temperatures. The CIRA 86 climatology is based on 1973-1978 measurements. Relatively large (1 K/yr) 5- to 10-year trends in temperatures as functions of longitude, latitude, and altitude have been observed for both the upper stratosphere (Clancy and Rusch, 1989a) and mesosphere (Clancy and Rusch, 1989b; Hauchecorne et al., 1991). The SME temperatures also exhibit enhanced amplitudes for the semiannual oscillation (SAO) of upper mesospheric temperatures at low latitudes, which are not evident in the CIRA 86 climatology. The so-called mesospheric `temperature inversions' at wintertime midlatitudes, which have been observed by ground-based lidar (Hauschecorne et al., 1987) and rocket in situ measurements (Schmidlin, 1976), are shown to be a climatological aspect of the mesosphere, based on the SME observations.

  18. Paul Bikle's Record Altitude Sailplane Flight

    NASA Video Gallery

    On a cold and windy February afternoon 50 years ago, the late Paul Bikle, then director of NASA's Flight Research Center, soared into the stratosphere with one goal in mind - a world altitude recor...

  19. Aeronautic Instruments. Section II : Altitude Instruments

    NASA Technical Reports Server (NTRS)

    Mears, A H; Henrickson, H B; Brombacher, W G

    1923-01-01

    This report is Section two of a series of reports on aeronautic instruments (Technical Report nos. 125 to 132, inclusive). This section discusses briefly barometric altitude determinations, and describes in detail the principal types of altimeters and barographs used in aeronautics during the recent war. This is followed by a discussion of performance requirements for such instruments and an account of the methods of testing developed by the Bureau of Standards. The report concludes with a brief account of the results of recent investigations. For accurate measurements of altitude, reference must also be made to thermometer readings of atmospheric temperature, since the altitude is not fixed by atmospheric pressure alone. This matter is discussed in connection with barometric altitude determination.

  20. High-altitude cerebral oedema mimicking stroke

    PubMed Central

    Yanamandra, Uday; Gupta, Amul; Patyal, Sagarika; Varma, Prem Prakash

    2014-01-01

    High-altitude cerebral oedema (HACO) is the most fatal high-altitude illness seen by rural physicians practising in high-altitude areas. HACO presents clinically with cerebellar ataxia, features of raised intracranial pressure (ICP) and coma. Early identification is important as delay in diagnosis can be fatal. We present two cases of HACO presenting with focal deficits mimicking stroke. The first patient presented with left-sided hemiplegia associated with the rapid deterioration in the sensorium. Neuroimaging revealed features suggestive of vasogenic oedema. The second patient presented with monoplegia of the lower limb. Neuroimaging revealed perfusion deficit in anterior cerebral artery territory. Both patients were managed with dexamethasone and they improved dramatically. Clinical picture and neuroimaging closely resembled acute ischaemic stroke in both cases. Thrombolysis in these patients would have been disastrous. Recent travel to high altitude, young age, absence of atherosclerotic risk factors and features of raised ICP concomitantly directed the diagnosis to HACO. PMID:24671373

  1. Altitude Testing of Large Liquid Propellant Engines

    NASA Technical Reports Server (NTRS)

    Maynard, Bryon; Raines, Nickey

    2008-01-01

    Altitude Testing of the J2-X engine at 100,000 feet (start capability). Chemical Steam Generation for providing vacuum. Project Started Mar 07. Test Stand Activation around Late 2010. J-2X Testing around early 2011.

  2. NGC 1252: a high altitude, metal poor open cluster remnant

    NASA Astrophysics Data System (ADS)

    de la Fuente Marcos, R.; de la Fuente Marcos, C.; Moni Bidin, C.; Carraro, G.; Costa, E.

    2013-09-01

    If stars form in clusters but most stars belong to the field, understanding the details of the transition from the former to the latter is imperative to explain the observational properties of the field. Aging open clusters are one of the sources of field stars. The disruption rate of open clusters slows down with age but, as an object gets older, the distinction between the remaining cluster or open cluster remnant (OCR) and the surrounding field becomes less and less obvious. As a result, finding good OCR candidates or confirming the OCR nature of some of the best candidates still remain elusive. One of these objects is NGC 1252, a scattered group of about 20 stars in Horologium. Here we use new wide-field photometry in the UBVI passbands, proper motions from the Yale/San Juan SPM 4.0 catalogue and high-resolution spectroscopy concurrently with results from N-body simulations to decipher NGC 1252's enigmatic character. Spectroscopy shows that most of the brightest stars in the studied area are chemically, kinematically and spatially unrelated to each other. However, after analysing proper motions, we find one relevant kinematic group. This sparse object is relatively close (˜1 kpc), metal poor and is probably not only one of the oldest clusters (3 Gyr) within 1.5 kpc from the Sun but also one of the clusters located farthest from the disc, at an altitude of nearly -900 pc. That makes NGC 1252 the first open cluster that can be truly considered a high Galactic altitude OCR: an unusual object that may hint at a star formation event induced on a high Galactic altitude gas cloud. We also conclude that the variable TW Horologii and the blue straggler candidate HD 20286 are unlikely to be part of NGC 1252. NGC 1252 17 is identified as an unrelated, Population II cannonball star moving at about 400 km s-1.

  3. High altitude medicine for family physicians.

    PubMed Central

    McMurray, S. J.

    1994-01-01

    High altitude medicine deals with a continuum of diseases ranging from a mild discomfort to serious ailments affecting all organ systems, including the lungs, brain, and eyes. Decreased oxygen tension is the primary cause. The main principles of prevention are staging and graded ascent to allow acclimatization. Adventure travel to high altitude destinations is becoming increasingly popular; family physicians should be informed of the medical problems associated with such travel. Images p712-a p715-a p716-a PMID:8199523

  4. 76 FR 11675 - IFR Altitudes; Miscellaneous Amendments

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-03

    ... Altitudes and Changeover Points From To MEA Sec. 95.1001 Direct Routes--U.S. Color Routes Sec. 95.516 Green... MEA MAA Sec. 95.3000 Low Altitude RNAV Routes Sec. 95.3278 RNAV Route T278 Is Amended To Read in Part... *5000 *1500--MOCA *2000--GNSS MEA Sec. 95.6020 VOR Federal Airway V20 Is Amended To Read in...

  5. Python Engine Installed in Altitude Wind Tunnel

    NASA Technical Reports Server (NTRS)

    1949-01-01

    An engine mechanic checks instrumentation prior to an investigation of engine operating characteristics and thrust control of a large turboprop engine with counter-rotating propellers under high-altitude flight conditions in the 20-foot-dianieter test section of the Altitude Wind Tunnel at the Lewis Flight Propulsion Laboratory of the National Advisory Committee for Aeronautics, Cleveland, Ohio, now known as the John H. Glenn Research Center at Lewis Field.

  6. The source altitude, electric current, and intrinsic brightness of terrestrial gamma ray flashes

    NASA Astrophysics Data System (ADS)

    Cummer, Steven A.; Briggs, Michael S.; Dwyer, Joseph R.; Xiong, Shaolin; Connaughton, Valerie; Fishman, Gerald J.; Lu, Gaopeng; Lyu, Fanchao; Solanki, Rahulkumar

    2014-12-01

    Many details of how thunderstorms generate terrestrial gamma ray flashes (TGFs) and other forms of high-energy radiation remain uncertain, including the basic question of where they are produced. We exploit the association of distinct low-frequency radio emissions with generation of terrestrial gamma ray flashes (TGFs) to directly measure for the first time the TGF source altitude. Analysis of two events reveals source altitudes of 11.8 ± 0.4 km and 11.9 ± 0.9 km. This places the source region in the interior of the thunderstorm between the two main charge layers and implies an intrinsic TGF brightness of approximately 1018 runaway electrons. The electric current in this nontraditional lightning process is found to be strong enough to drive nonlinear effects in the ionosphere, and in one case is comparable to the highest peak current lightning processes on the planet.

  7. High altitude color photography as a tool for regional analysis: As demonstrated for southeastern Florida

    NASA Technical Reports Server (NTRS)

    Eyre, L. A.

    1972-01-01

    High altitude color and color infrared photography of the tri-county region of southeast Florida made it feasible to evaluate its potential for quantifying the dimensions of regional change. Attention was focused upon three main aspects of change in the region, which in fact overlap. These were; (1) the transformation of the southeast Florida wetlands; (2) the expansion of agriculture; and (3) the growth of the urbanized area. The development analyzed covered the period of thirteen years from 1956 to 1969. Results using this new 18 km photography were superior because of the degree of resolution, the combined power of color and color infrared interpretation, and the large area covered by each frame. The greatest advantage of high altitude imagery is the time-saving element, since it is possible to delineate and identify major geographic patterns over thousands of sq km very rapidly.

  8. Altitude profiles of O2 on Mars from SPICAM stellar occultations

    NASA Astrophysics Data System (ADS)

    Sandel, B. R.; Gröller, H.; Yelle, R. V.; Koskinen, T.; Lewis, N. K.; Bertaux, J.-L.; Montmessin, F.; Quémerais, E.

    2015-05-01

    We determine the first altitude profiles of O2 in the important photochemical region below 120 km in the atmosphere of Mars by analyzing Mars Express/SPICAM ultraviolet observations of six occultations of stars by the atmosphere. Over the range of 90-130 km the altitude-averaged mixing ratio of O2 relative to the major constituent CO2 varies in space and time in the range of 3.1 ×10-3 - 5.8 ×10-3 , with a mean value of 4.0 ×10-3 . This mean value exceeds by a factor of 3-4 those reported earlier for the lower atmosphere. However, some of the O2 abundance and mixing ratio profiles determined here are similar to those measured by Viking in 1976 in the upper atmosphere.

  9. Laboratory evaluation of an airborne ozone instrument that compensates for altitude/sensitivity effects

    NASA Technical Reports Server (NTRS)

    Gregory, G. L.; Hudgins, C. H.; Edahl, R. A., Jr.

    1983-01-01

    One problem encountered in the use of air-quality instrumentation on aircraft is the variation of instrument sensitivity with pressure as the result of altitude changes of the aircraft. Many instruments experience sensitivity changes of as much as a factor of 2 at altitudes of 6 km. Discussed are recent modifications to a chemiluminescent (ethylene) ozone detector that allow the instrument to automatically compensate for pressure/sensitivity effects. The modification provides automated mass flow rate control for both the sample and ethylene gas flows. The flow control systems maintain flow rate to within 15 percent for a 100-torr instantaneous pressure change, and flow rates are returned to the desired set points within 10 s after the pressure change. During simulated altitude changes (300 m/min from mean sea level to 3-km altitude), flow rates were controlled to within 3 percent of the set point. Laboratory data are summarized verifying the operation of the instrument for a pressure range of 760 torr (sea level) to 350 torr (approximately 20,000 ft) and an ozone concentration range from 20 to approximately 700 ppb.

  10. Anisotropic fluid modeling of ionospheric upflow: Effects of low-altitude anisotropy and thermospheric winds

    NASA Astrophysics Data System (ADS)

    Burleigh, M.; Zettergren, M.

    2017-01-01

    A new anisotropic fluid model is developed to describe ionospheric upflow responses to magnetospheric forcing by electric fields and broadband ELF waves at altitudes of 90-2500 km. This model is based on a bi-Maxwellian ion distribution and solves time-dependent, nonlinear equations of conservation of mass, momentum, parallel energy, and perpendicular energy for six ion species important to E, F, and topside ionospheric regions. It includes chemical and collisional interactions with the neutral atmosphere, photoionization, and electron impact ionization. This model is used to examine differences between isotropic and anisotropic descriptions of ionospheric upflow driven by DC electric fields, possible effects of low-altitude (<500 km) wave heating, and impacts of neutral winds on ion upflow. Results indicate that isotropic models may overestimate field-aligned ion velocity responses by as much as ˜48%. Simulations also show significant ionospheric responses at low altitudes to wave heating for very large power spectral densities, but ion temperature anisotropies below the F region peak are dominated by frictional heating from DC electric fields. Neutral winds are shown to play an important role regulating ion upflow. Thermospheric winds can enhance or suppress upward fluxes driven by DC and BBELF fields by 10-20% for the cases examined. The time history of the neutral winds also affects the amount of ionization transported to higher altitudes by DC electric fields.

  11. Cabin cruising altitudes for regular transport aircraft.

    PubMed

    2008-04-01

    The adverse physiological effects of flight, caused by ascent to altitude and its associated reduction in barometric pressure, have been known since the first manned balloon flights in the 19th century. It soon became apparent that the way to protect the occupant of an aircraft from the effects of ascent to altitude was to enclose either the individual, or the cabin, in a sealed or pressurized environment. Of primary concern in commercial airline transport operations is the selection of a suitable cabin pressurization schedule that assures adequate oxygen partial pressures for all intended occupants. For the past several decades, 8000 ft has been accepted as the maximum operational cabin pressure altitude in the airline industry. More recent research findings on the physiological and psycho-physiological effects of mild hypoxia have provided cause for renewed discussion of the "acceptability" of a maximum cabin cruise altitude of 8000 ft; however, we did not find sufficient scientific data to recommend a change in the cabin altitude of transport category aircraft. The Aerospace Medical Association (AsMA) should support further research to evaluate the safety, performance and comfort of occupants at altitudes between 5000 and 10,000 ft.

  12. Early history of high-altitude physiology.

    PubMed

    West, John B

    2016-02-01

    High-altitude physiology can be said to have begun in 1644 when Torricelli described the first mercury barometer and wrote the immortal words "We live submerged at the bottom of an ocean of the element air." Interestingly, the notion of atmospheric pressure had eluded his teacher, the great Galileo. Blaise Pascal was responsible for describing the fall in pressure with increasing altitude, and Otto von Guericke gave a dramatic demonstration of the enormous force that could be developed by atmospheric pressure. Robert Boyle learned of Guericke's experiment and, with Robert Hooke, constructed the first air pump that allowed small animals to be exposed to a low pressure. Hooke also constructed a small low-pressure chamber and exposed himself to a simulated altitude of about 2400 meters. With the advent of ballooning, humans were rapidly exposed to very low pressures, sometimes with tragic results. For example, the French balloon, Zénith, rose to over 8000 m, and two of the three aeronauts succumbed to the hypoxia. Paul Bert was the first person to clearly state that the deleterious effects of high altitude were caused by the low partial pressure of oxygen (PO2), and later research was accelerated by high-altitude stations and expeditions to high altitude.

  13. KM3NeT: towards a km 3-scale neutrino telescope in the Mediterranean Sea

    NASA Astrophysics Data System (ADS)

    Distefano, C.; KM3NeT Consortium

    2009-05-01

    The observation of high energy neutrinos ( ≳1 TeV) from astrophysical sources would substantially improve our knowledge and understanding of the non-thermal processes in these sources, and would in particular pinpoint the accelerators of cosmic rays. Theoretical predictions indicate that km 3-scale detectors are needed to detect astrophysical neutrino fluxes. That is the reason why the three Mediterranean experiments, ANTARES, NEMO and NESTOR are working together on preparing KM3NeT, a large deep-sea neutrino telescope in the Mediterranean Sea which will survey a large part of the Galactic disc, including the Galactic Centre. It will complement the IceCube telescope currently under construction at the South Pole. Furthermore, the improved optical properties of sea water, compared to Antarctic ice, will allow for a better angular resolution and hence a better background rejection. The construction of this detector will require the solution of technological problems common to many deep submarine installations, and will help paving the way for other deep-sea research facilities. In this paper the major activities and the status of KM3NeT are presented.

  14. KM3NeT: towards a km3-scale neutrino telescope in the Mediterranean Sea

    NASA Astrophysics Data System (ADS)

    Km3NeT Consortium; Distefano, C.; KM3NeT Consortium

    2009-05-01

    The observation of high energy neutrinos (≳1 TeV) from astrophysical sources would substantially improve our knowledge and understanding of the non-thermal processes in these sources, and would in particular pinpoint the accelerators of cosmic rays. Theoretical predictions indicate that km3-scale detectors are needed to detect astrophysical neutrino fluxes. That is the reason why the three Mediterranean experiments, ANTARES, NEMO and NESTOR are working together on preparing KM3NeT, a large deep-sea neutrino telescope in the Mediterranean Sea which will survey a large part of the Galactic disc, including the Galactic Centre. It will complement the IceCube telescope currently under construction at the South Pole. Furthermore, the improved optical properties of sea water, compared to Antarctic ice, will allow for a better angular resolution and hence a better background rejection. The construction of this detector will require the solution of technological problems common to many deep submarine installations, and will help paving the way for other deep-sea research facilities. In this paper the major activities and the status of KM3NeT are presented.

  15. Passive microwave observations of thunderstorms from high-altitude aircraft

    NASA Technical Reports Server (NTRS)

    Heymsfield, Gerald M.; Fulton, Richard

    1988-01-01

    A high-altitude (20 km) aircraft made overflights of severe and nonsevere Midwest thunderstorms in the central and southeast U.S. during 2 separate experiments. Down-looking instruments on the aircraft are the imaging Multi-Channel Cloud Radiometer with channels in the visible, IR, and near IR, and two passive microwave instruments, the imaging Advanced Microwave Moisture Sounder at 92 (atmospheric window) and 183 GHz (centered on a water vapor line) and the 45 deg foward-of-nadir Multi-Channel Precipitation Radiometer at the 18 and 37 GHz window channels. Over land, the 92 GHz frequency distinguishes quite well the precipitating region from the nonprecipitating anvil region. The interpretation of the microwave measurements is complicated by differences in the cloud microphysics between different climatic regions.

  16. High resolution spectroscopy from low altitude satellites. [gamma ray astronomy

    NASA Technical Reports Server (NTRS)

    Nakano, G. H.; Imhof, W. L.

    1978-01-01

    The P 78 1 satellite to be placed in a synchronous polar orbit at an altitude of 550-660 km will carry two identical high resolution spectrometers each consisting of a single (approximately 85 cc) intrinsic germanium IGE detector. The payload also includes a pair of phoswitch scintillators, an array of CdTe detectors and several particle detectors, all of which are mounted on the wheel of the satellite. The intrinsic high purity IGE detectors receive cooling from two Stirling cycle refrigerators and facilitate the assembly of large and complex detector arrays planned for the next generation of high sensitivity instruments such as those planned for the gamma ray observatory. The major subsystems of the spectrometer are discussed as well as its capabilities.

  17. A nominal set of high-altitude EMP environments

    SciTech Connect

    Longmire, C.L.; Hamilton, R.M.; Hahn, J.M.

    1987-02-01

    This report presents high-altitude EMP (HEMP) environments calculated by the CHAP code for a nominal large yield burst at 400 km over the central US. Nominal, unclassified weapon output parameters were used, along with unclassified EMP theory and calculational techniques. While the resulting environments do not represent upper bounds, they should be useful in developing understanding of the effect of HEMP on electrical and electronic systems. The calculated environments illustrate the wide variability of the HEMP from a single burst, depending on ground range and azimuth from ground zero. Analytic fits to the HEMP fields are provided to facilitate coupling calculations. The CHAP results are justified by a detailed examination of Compton currents, air conductivities, and the resulting fields. It is shown that both HEMP theory and the calculations conserve energy scrupulously.

  18. SAGE II aerosol validation: selected altitude measurements, including particle micromeasurements.

    PubMed

    Oberbeck, V R; Livingston, J M; Russell, P B; Pueschel, R F; Rosen, J N; Osborn, M T; Kritz, M A; Snetsinger, K G; Ferry, G V

    1989-06-20

    Correlative aerosol measurements taken at a limited number of altitudes during coordinated field experiments are used to test the validity of particulate extinction coefficients derived from limb path solar radiance measurements taken by the Stratospheric Aerosol and Gas Experiment (SAGE) II Sun photometer. In particular, results are presented from correlative measurement missions that were conducted during January 1985, August 1985, and July 1986. Correlative sensors included impactors, laser spectrometers, and filter samplers aboard an U-2-airplane, an upward pointing lidar aboard a P-3 airplane, and balloon-borne optical particle counters (dustsondes). The main body of this paper focuses on the July 29, 1986, validation experiment, which minimized the many difficulties (e.g., spatial and temporal inhomogeneities, imperfect coincidences) that can complicate the validation process. On this day, correlative aerosol measurements taken at an altitude of 20.5 km agreed with each other within their respective uncertainties, and particulate extinction values calculated at SAGE II wavelengths from these measurements validated corresponding SAGE II values. Additional validation efforts on days when measurement and logistical conditions were much less favorable for validation are discussed in an appendix.

  19. Atmospheric Sampling of Aerosols to Stratospheric Altitudes using High Altitude Balloons

    NASA Astrophysics Data System (ADS)

    Jerde, E. A.; Thomas, E.

    2010-12-01

    Although carbon dioxide represents a long-lived atmospheric component relevant to global climate change, it is also understood that many additional contributors influence the overall climate of Earth. Among these, short-lived components are more difficult to incorporate into models due to uncertainties in the abundances of these both spatially and temporally. Possibly the most significant of these short-lived components falls under the heading of “black carbon” (BC). There are numerous overlapping definitions of BC, but it is basically carbonaceous in nature and light absorbing. Due to its potential as a climate forcer, an understanding of the BC population in the atmosphere is critical for modeling of radiative forcing. Prior measurements of atmospheric BC generally consist of airplane- and ground-based sampling, typically below 5000 m and restricted in time and space. Given that BC has a residence time on the order of days, short-term variability is easily missed. Further, since the radiative forcing is a result of BC distributed through the entire atmospheric column, aircraft sampling is by definition incomplete. We are in the process of planning a more comprehensive sampling of the atmosphere for BC using high-altitude balloons. Balloon-borne sampling is a highly reliable means to sample air through the entire troposphere and into the lower stratosphere. Our system will incorporate a balloon and a flight train of two modules. One module will house an atmospheric sampler. This sampler will be single-stage (samples all particle sizes together), and will place particles directly on an SEM sample stub for analysis. The nozzle depositing the sample will be offset from the center of the stub, placing the aerosol particles toward the edge. At various altitudes, the stub will be rotated 45 degrees, providing 6-8 sample “cuts” of particle populations through the atmospheric column. The flights will reach approximately 27 km altitude, above which the balloons

  20. Evolution of Titan's atmospheric aerosol under high-altitude ultraviolet irradiation

    NASA Astrophysics Data System (ADS)

    Tigrine, S.; Carrasco, N.; Mahjoub, A.; Fleury, B.; Cernogora, G.; Nahon, L.; Pernot, P.; Gudipati, M.

    2015-10-01

    The Cassini-Huygens space mission revealed that the chemistry initiating Titan's aerosols formation starts in the upper layers of the atmosphere (~1000 km). The grains then sediment until deposition at the surface. Despite all the data collected, the photochemical evolution of the aerosols between 1000 and 600 km is still unknown, especially regarding their optical properties. The aim of this work is to investigate the photochemical aging processes of those aerosols and how they interact with the VUV solar radiations. We put our results in perspective with the Cassini data for different atmospheric altitudes.

  1. Macroscopic time and altitude distribution of plasma turbulence induced in ionospheric modification experiments

    SciTech Connect

    Rose, H.; Dubois, D.; Russell, D.; Hanssen, A.

    1996-03-01

    This is the final report of a three-year Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). This research concentrated on the time dependence of the heater, induced-turbulence, and electron-density profiles excited in the ionosphere by a powerful radio-frequency heater wave. The macroscopic density is driven by the ponderomotive pressure and the density self-consistently determines the heater propagation. For typical parameters of the current Arecibo heater, a dramatic quasi-periodic behavior was found. For about 50 ms after turn-on of the heater wave, the turbulence is concentrated at the first standing-wave maximum of the heater near reflection altitude. From 50--100 ms the standing-wave pattern drops by about 1--2 km in altitude and the quasi-periodicity reappears at the higher altitudes with a period of roughly 50 ms. This behavior is due to the half-wavelength density depletion grating that is set up by the ponderomotive pressure at the maxima of the heater standing-wave pattern. Once the grating is established the heater can no longer propagate to higher altitudes. The grating is then unsupported by the heater at these altitudes and decays, allowing the heater to propagate again and initiate another cycle. For stronger heater powers, corresponding to the Arecibo upgrade and the HAARP heater now under construction, the effects are much more dramatic.

  2. A Hyperspectral Thermal Emission Spectrometer (HyTES) for High Altitude Applications

    NASA Astrophysics Data System (ADS)

    Mihaly, J. M.; Johnson, W. R.; Eng, B. T.; Staniszewski, Z. K.; Hook, S. J.

    2015-12-01

    The Hyperspectral Thermal Emission Spectrometer (HyTES) is an airborne imaging spectrometer developed by JPL and originally configured on the Twin Otter aircraft. The instrument utilizes a thermal infrared Dyson imaging spectrometer and provides 256 spectral channels between 7.5 and 12 micrometers with 512 spatial pixels cross-track over a 50 degree field of view. HyTES has successfully completed multiple campaigns on the low altitude Twin Otter platform and is now capable of routinely capturing multi-species gas plumes over urban and other science-applicable environments. Current system upgrades and modifications are underway to configure HyTES on the ER-2 high altitude aircraft. The ER-2 aircraft will fly at an altitude greater than 18 km (60,000 ft) and provide a wide swath width with 35 m ground pixel size. High altitude observations from HyTES on the ER-2 platform will be used to support HyspIRI TIR measurement development. The modifications to the system maintain the capability of the HyTES instrument on the Twin Otter aircraft and a new vacuum enclosure significantly reduces both the mass and volume of the instrument scanhead. The current instrument performance, upgrades, and specifications of the high altitude system will be presented.

  3. Design study for a gound microwave power transmission system for use with a high-altitude powered platform

    NASA Technical Reports Server (NTRS)

    Brown, W. C.

    1983-01-01

    The conceptual design of a ground-based microwave power transmission system is described. This system is intended to supply electrical power via an air link to a high-altitude (21 km) powered platform. The platform must be equipped with the required instrumentation (RECTENNA) to convert the RF energy to dc power.

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

    DTIC Science & Technology

    2010-01-01

    based horizontal meteor winds observed at 69°N ( Andenes , Norway) and 85 km geometric altitude in Figure 5. In addition, we performed five short term...calculating winds and the Andenes data. 2.2. Ice Particle Trajectories and CARMA [22] As noted earlier, our approach is a two‐step process. We first use

  5. Extremely Low Ionospheric Peak Altitudes in the Polar-Hole Region

    NASA Technical Reports Server (NTRS)

    Benson, Robert F.; Grebowsky, Joseph M.

    1999-01-01

    Vertical electron-density (N (sub e)) profiles, deduced from newly-available ISIS-II digital ionospheric topside-sounder data, are used to investigate the "polar-hole" region within the winter, nighttime polar cap ionosphere during solar minimum. The hole region is located around 0200 MLT near the poleward side of the auroral oval. Earlier investigations had revealed very low N (sub e) values in this region (down to 200/cu cm near 300 km). In the present study, such low N, values (approx. 100/cu cm) were only found near the ISIS (International Satellite for Ionospheric Study)-II altitude of 1400 km. The peak ionospheric concentration below the spacecraft remained fairly constant (approx. 10 (exp 5)/cu cm across the hole region but the altitude of the peak dropped dramatically. This peak dropped, surprisingly, to the vicinity of 100 km. These observations suggest that the earlier satellite in situ measurements, interpreted as deep holes in the ionospheric F-region concentration, could have been made during conditions of an extreme decrease in the altitude of the ionospheric N (sub e) peak. The observations, in combination with other data, indicate that the absence of an F-layer peak may be a frequent occurrence at high latitudes.

  6. Nitric oxide in adaptation to altitude.

    PubMed

    Beall, Cynthia M; Laskowski, Daniel; Erzurum, Serpil C

    2012-04-01

    This review summarizes published information on the levels of nitric oxide gas (NO) in the lungs and NO-derived liquid-phase molecules in the acclimatization of visitors newly arrived at altitudes of 2500 m or more and adaptation of populations whose ancestors arrived thousands of years ago. Studies of acutely exposed visitors to high altitude focus on the first 24-48 h with just a few extending to days or weeks. Among healthy visitors, NO levels in the lung, plasma, and/or red blood cells fell within 2h, but then returned toward baseline or slightly higher by 48 h and increased above baseline by 5 days. Among visitors ill with high-altitude pulmonary edema at the time of the study or in the past, NO levels were lower than those of their healthy counterparts. As for highland populations, Tibetans had NO levels in the lung, plasma, and red blood cells that were at least double and in some cases orders of magnitude greater than other populations regardless of altitude. Red blood cell-associated nitrogen oxides were more than 200 times higher. Other highland populations had generally higher levels although not to the degree shown by Tibetans. Overall, responses of those acclimatized and those presumed to be adapted are in the same direction, although the Tibetans have much larger responses. Missing are long-term data on lowlanders at altitude showing how similar they become to the Tibetan phenotype. Also missing are data on Tibetans at low altitude to see the extent to which their phenotype is a response to the immediate environment or expressed constitutively. The mechanisms causing the visitors' and the Tibetans' high levels of NO and NO-derived molecules at altitude remain unknown. Limited data suggest processes including hypoxic upregulation of NO synthase gene expression, hemoglobin-NO reactions, and genetic variation. Gains in understanding will require integrating appropriate methods and measurement techniques with indicators of adaptive function under hypoxic

  7. Nitric oxide in adaptation to altitude

    PubMed Central

    Laskowski, Daniel; Erzurum, Serpil C.

    2012-01-01

    This review summarizes published information on levels of nitric oxide gas (NO) in the lungs and NO-derived liquid phase molecules in the acclimatization of visitors newly arrived at altitudes of 2500m or more and adaptation of populations whose ancestors arrived thousands of years ago. Studies of acutely exposed visitors to high altitude focus on the first 24–48 hours with just a few extending to days or weeks. Among healthy visitors, NO levels in the lung, plasma and/or red blood cells fell within three hours, but then returned toward baseline or slightly higher by 48 hours, and increased above baseline by 5 days. Among visitors ill with high-altitude pulmonary edema at the time of the study or in the past, NO levels were lower than their healthy counterparts. As for highland populations, Tibetans had NO levels in the lung, plasma and red blood cells that were at least double and in some cases orders of magnitude greater than other populations regardless of altitude. Red blood cell associated nitrogen oxides were more than two hundred times higher. Other highland populations had generally higher levels although not to the degree showed by Tibetans. Overall, responses of those acclimatized and those presumed to be adapted are in the same direction although the Tibetans have much larger responses. Missing are long-term data on lowlanders at altitude showing how similar they become to the Tibetan phenotype. Also missing are data on Tibetans at low altitude to see the extent to which their phenotype is a response to the immediate environment or expressed constitutively. The mechanisms causing the visitors’ and the Tibetans’ high levels of NO and NO-derived molecules at altitude remain unknown. Limited data suggest processes including hypoxic upregulation of NO synthase gene expression, hemoglobin-NO reactions and genetic variation. Gains in understanding will require integrating appropriate methods and measurement techniques with indicators of adaptive function

  8. 14 CFR 23.1527 - Maximum operating altitude.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Maximum operating altitude. 23.1527 Section... Information § 23.1527 Maximum operating altitude. (a) The maximum altitude up to which operation is allowed... established. (b) A maximum operating altitude limitation of not more than 25,000 feet must be established...

  9. 14 CFR 23.1527 - Maximum operating altitude.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Maximum operating altitude. 23.1527 Section... Information § 23.1527 Maximum operating altitude. (a) The maximum altitude up to which operation is allowed... established. (b) A maximum operating altitude limitation of not more than 25,000 feet must be established...

  10. 14 CFR 23.1527 - Maximum operating altitude.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Maximum operating altitude. 23.1527 Section... Information § 23.1527 Maximum operating altitude. (a) The maximum altitude up to which operation is allowed... established. (b) A maximum operating altitude limitation of not more than 25,000 feet must be established...

  11. 14 CFR 91.119 - Minimum safe altitudes: General.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 2 2013-01-01 2013-01-01 false Minimum safe altitudes: General. 91.119... § 91.119 Minimum safe altitudes: General. Except when necessary for takeoff or landing, no person may operate an aircraft below the following altitudes: (a) Anywhere. An altitude allowing, if a power...

  12. 14 CFR 91.119 - Minimum safe altitudes: General.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 2 2014-01-01 2014-01-01 false Minimum safe altitudes: General. 91.119... § 91.119 Minimum safe altitudes: General. Except when necessary for takeoff or landing, no person may operate an aircraft below the following altitudes: (a) Anywhere. An altitude allowing, if a power...

  13. 14 CFR 91.119 - Minimum safe altitudes: General.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 2 2012-01-01 2012-01-01 false Minimum safe altitudes: General. 91.119... § 91.119 Minimum safe altitudes: General. Except when necessary for takeoff or landing, no person may operate an aircraft below the following altitudes: (a) Anywhere. An altitude allowing, if a power...

  14. 14 CFR 23.1527 - Maximum operating altitude.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Maximum operating altitude. 23.1527 Section... Information § 23.1527 Maximum operating altitude. (a) The maximum altitude up to which operation is allowed... established. (b) A maximum operating altitude limitation of not more than 25,000 feet must be established...

  15. 14 CFR 91.119 - Minimum safe altitudes: General.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false Minimum safe altitudes: General. 91.119... § 91.119 Minimum safe altitudes: General. Except when necessary for takeoff or landing, no person may operate an aircraft below the following altitudes: (a) Anywhere. An altitude allowing, if a power...

  16. 14 CFR 91.119 - Minimum safe altitudes: General.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 2 2011-01-01 2011-01-01 false Minimum safe altitudes: General. 91.119... § 91.119 Minimum safe altitudes: General. Except when necessary for takeoff or landing, no person may operate an aircraft below the following altitudes: (a) Anywhere. An altitude allowing, if a power...

  17. 14 CFR 23.1527 - Maximum operating altitude.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Maximum operating altitude. 23.1527 Section... Information § 23.1527 Maximum operating altitude. (a) The maximum altitude up to which operation is allowed... established. (b) A maximum operating altitude limitation of not more than 25,000 feet must be established...

  18. Responses of the autonomic nervous system in altitude adapted and high altitude pulmonary oedema subjects

    NASA Astrophysics Data System (ADS)

    Mathew, Lazar; Purkayastha, S. S.; Jayashankar, A.; Radhakrishnan, U.; Sen Gupta, J.; Nayar, H. S.

    1985-06-01

    Studies were carried out to ascertain the role of sympatho-parasympathetic responses in the process of adaptation to altitude. The assessment of status of autonomic balance was carried out in a group of 20 young male subjects by recording their resting heart rate, blood pressure, oral temperature, mean skin temperature, extremity temperatures, pupillary diameter, cold pressor response, oxygen consumption, cardioacceleration during orthostasis and urinary excretion of catecholamines; in a thermoneutral laboratory. The same parameters were repeated on day 3 and at weekly intervals for a period of 3 weeks, after exposing them to 3,500 m; and also after return to sea level. At altitude, similar studies were carried out in a group of 10 acclimatized lowlanders, 10 high altitude natives and 6 patients who had recently recovered from high altitude pulmonary oedema. In another phase, similar studies were done in two groups of subjects, one representing 15 subjects who had stayed at altitude (3,500 4,000 m) without any ill effects and the other comprising of 10 subjects who had either suffered from high altitude pulmonary oedema (HAPO) or acute mountain sickness (AMS). The results revealed sympathetic overactivity on acute induction to altitude which showed gradual recovery on prolonged stay, the high altitude natives had preponderance to parasympathetic system. Sympathetic preponderance may not be an essential etiological factor for the causation of maladaptation syndromes.

  19. High altitude pulmonary edema in mountain climbers.

    PubMed

    Korzeniewski, Krzysztof; Nitsch-Osuch, Aneta; Guzek, Aneta; Juszczak, Dariusz

    2015-04-01

    Every year thousands of ski, trekking or climbing fans travel to the mountains where they stay at the altitude of more than 2500-3000m above sea level or climb mountain peaks, often exceeding 7000-8000m. High mountain climbers are at a serious risk from the effects of adverse environmental conditions prevailing at higher elevations. They may experience health problems resulting from hypotension, hypoxia or exposure to low temperatures; the severity of those conditions is largely dependent on elevation, time of exposure as well as the rate of ascent and descent. A disease which poses a direct threat to the lives of mountain climbers is high altitude pulmonary edema (HAPE). It is a non-cardiogenic pulmonary edema which typically occurs in rapidly climbing unacclimatized lowlanders usually within 2-4 days of ascent above 2500-3000m. It is the most common cause of death resulting from the exposure to high altitude. The risk of HAPE rises with increased altitude and faster ascent. HAPE incidence ranges from an estimated 0.01% to 15.5%. Climbers with a previous history of HAPE, who ascent rapidly above 4500m have a 60% chance of illness recurrence. The aim of this article was to present the relevant details concerning epidemiology, pathophysiology, clinical symptoms, prevention, and treatment of high altitude pulmonary edema among climbers in the mountain environment.

  20. [Effects of high altitude on bronchial asthma].

    PubMed

    Schultze-Werninghaus, G

    2008-03-01

    Sojourns in the high mountains have been recommended to patients with asthma for many decades. It is the aim of this contribution to summarise the published studies about the effects of a stay at > 1500 m above sea level on asthmatic patients. These data from 428 adolescent and adult patients indicate an improvement of asthma symptoms and lung function during sojourns at high altitude. In many patients a reduction of the steroid therapy was achievable. Profound changes in the immune system have been demonstrated at high altitude, with a reduction of B- and T-helper cell activation. Total and mite-specific immunoglobulin E antibodies decrease significantly during longer sojourns. These changes are associated with a reduction of airway inflammation (e. g., reduction of eosinophil activation, NO exhalation and bronchial hyper-responsiveness). The fact that also patients with non-allergic asthma demonstrate a reduction of their airway inflammation at high altitude suggests that the high altitude climate has beneficial effects on asthma beyond the effects of allergen avoidance. High UV exposure and low humidity could be important additional factors, to explain the reductions in asthma severity in the high mountain climate. Larger controlled studies should be performed to prove the positive effects of the high altitude climate on asthma.

  1. Wind study for high altitude platform design

    NASA Technical Reports Server (NTRS)

    Strganac, T. W.

    1979-01-01

    An analysis of upper air winds was performed to define the wind environment at potential operating altitudes for high altitude powered platform concepts. Wind conditions of the continental United States, Pacific area (Alaska to Sea of Japan), and European area (Norwegian and Mediterranean Sea) were obtained using a representative network of sites selected based upon adequate high altitude sampling, geographic dispersion, and observed upper wind patterns. A data base of twenty plus years of rawinsonde gathered wind information was used in the analysis. Annual variations from surface to 10 mb pressure altitude were investigated to encompass the practical operating range for the platform concepts. Parametric analysis for the United States and foreign areas was performed to provide a basis for vehicle system design tradeoffs. This analysis of wind magnitudes indicates the feasibility of annual operation at a majority of sites and more selective seasonal operation for the extreme conditions between the pressure altitudes of 100 to 25 mb based upon the assumed design speeds.

  2. Pulmonary Embolism Masquerading as High Altitude Pulmonary Edema at High Altitude.

    PubMed

    Pandey, Prativa; Lohani, Benu; Murphy, Holly

    2016-12-01

    Pandey, Prativa, Benu Lohani, and Holly Murphy. Pulmonary embolism masquerading as high altitude pulmonary edema at high altitude. High Alt Med Biol. 17:353-358, 2016.-Pulmonary embolism (PE) at high altitude is a rare entity that can masquerade as or occur in conjunction with high altitude pulmonary edema (HAPE) and can complicate the diagnosis and management. When HAPE cases do not improve rapidly with descent, other diagnoses, including PE, ought to be considered. From 2013 to 2015, we identified eight cases of PE among 303 patients with initial diagnosis of HAPE. Upon further evaluation, five had deep vein thrombosis (DVT). One woman had a contraceptive ring and seven patients had no known thrombotic risks. PE can coexist with or mimic HAPE and should be considered in patients presenting with shortness of breath from high altitude regardless of thrombotic risk.

  3. Pulmonary Embolism Masquerading as High Altitude Pulmonary Edema at High Altitude

    PubMed Central

    Lohani, Benu; Murphy, Holly

    2016-01-01

    Abstract Pandey, Prativa, Benu Lohani, and Holly Murphy. Pulmonary embolism masquerading as high altitude pulmonary edema at high altitude. High Alt Med Biol. 17:353–358, 2016.—Pulmonary embolism (PE) at high altitude is a rare entity that can masquerade as or occur in conjunction with high altitude pulmonary edema (HAPE) and can complicate the diagnosis and management. When HAPE cases do not improve rapidly with descent, other diagnoses, including PE, ought to be considered. From 2013 to 2015, we identified eight cases of PE among 303 patients with initial diagnosis of HAPE. Upon further evaluation, five had deep vein thrombosis (DVT). One woman had a contraceptive ring and seven patients had no known thrombotic risks. PE can coexist with or mimic HAPE and should be considered in patients presenting with shortness of breath from high altitude regardless of thrombotic risk. PMID:27768392

  4. MODIS 3km Aerosol Product: Algorithm and Global Perspective

    NASA Technical Reports Server (NTRS)

    Remer, L. A.; Mattoo, S.; Levy, R. C.; Munchak, L.

    2013-01-01

    After more than a decade of producing a nominal 10 km aerosol product based on the dark target method, the MODIS aerosol team will be releasing a nominal 3 km product as part of their Collection 6 release. The new product differs from the original 10 km product only in the manner in which reflectance pixels are ingested, organized and selected by the aerosol algorithm. Overall, the 3 km product closely mirrors the 10 km product. However, the finer resolution product is able to retrieve over ocean closer to islands and coastlines, and is better able to resolve fine aerosol features such as smoke plumes over both ocean and land. In some situations, it provides retrievals over entire regions that the 10 km product barely samples. In situations traditionally difficult for the dark target algorithm, such as over bright or urban surfaces the 3 km product introduces isolated spikes of artificially high aerosol optical depth (AOD) that the 10 km algorithm avoids. Over land, globally, the 3 km product appears to be 0.01 to 0.02 higher than the 10 km product, while over ocean, the 3 km algorithm is retrieving a proportionally greater number of very low aerosol loading situations. Based on collocations with ground-based observations for only six months, expected errors associated with the 3 km land product are determined to be greater than for the 10 km product: 0.05 0.25 AOD. Over ocean, the suggestion is for expected errors to be the same as the 10 km product: 0.03 0.05 AOD. The advantage of the product is on the local scale, which will require continued evaluation not addressed here. Nevertheless, the new 3 km product is expected to provide important information complementary to existing satellite-derived products and become an important tool for the aerosol community.

  5. Sonic Thermometer for High-Altitude Balloons

    NASA Technical Reports Server (NTRS)

    Bognar, John

    2012-01-01

    The sonic thermometer is a specialized application of well-known sonic anemometer technology. Adaptations have been made to the circuit, including the addition of supporting sensors, which enable its use in the high-altitude environment and in non-air gas mixtures. There is a need to measure gas temperatures inside and outside of superpressure balloons that are flown at high altitudes. These measurements will allow the performance of the balloon to be modeled more accurately, leading to better flight performance. Small thermistors (solid-state temperature sensors) have been used for this general purpose, and for temperature measurements on radiosondes. A disadvantage to thermistors and other physical (as distinct from sonic) temperature sensors is that they are subject to solar heating errors when they are exposed to the Sun, and this leads to issues with their use in a very high-altitude environment

  6. Tests of artificial flight at high altitudes

    NASA Technical Reports Server (NTRS)

    Gradenwitz, Arthur

    1920-01-01

    If we wish to form an accurate idea of the extraordinary progress achieved in aeronautics, a comparison must be made of the latest altitude records and the figures regarded as highest attainable limit some ten years ago. It is desirable, for two reasons, that we should be able to define the limit of the altitudes that can be reached without artificial aid. First, to know to what extent the human body can endure the inhalation of rarified air. Second, the mental capacity of the aviator must be tested at high altitudes and the limit known below which he is able to make reliable observations without being artificially supplied with oxygen. A pneumatic chamber was used for the most accurate observations.

  7. Paschen Considerations for High Altitude Airships

    NASA Technical Reports Server (NTRS)

    Ferguson, D. C.; Hillard, G. B.

    2004-01-01

    Recently, there have been several proposals submitted to funding agencies for long-lived high altitude (about 70,000 feet) airships for communications, surveillance, etc. In order for these airships to remain at altitude, high power, high efficiency, lightweight solar arrays must be used, and high efficiency power management and distribution systems must be employed. The needs for high power and high efficiency imply high voltage systems. However, the air pressure at these extreme altitudes is such that electrical power systems will be near the Paschen discharge minimum over a wide range of electrode separations. In this paper, preliminary calculations are made for acceptable high voltage design practices under ambient, hydrogen and helium gas atmospheres.

  8. Low-Altitude Magnetic Topology with MAVEN SWEA and MAG

    NASA Astrophysics Data System (ADS)

    Mitchell, David; Xu, Shaosui; Mazelle, Christian; Luhmann, Janet; McFadden, James; Connerney, John; Liemohn, Michael; Dong, Chuanfei; Bougher, Stephen; Fillingim, Matthew

    2016-04-01

    The Solar Wind Electron Analyzer (SWEA) and Magnetometer (MAG) onboard the MAVEN spacecraft measure electron pitch angle and energy distributions at 2-second resolution (~8 km along the orbit track) to determine the topology of magnetic fields from both external and crustal sources. Electrons from different regions of the Mars environment can be distinguished by their energy distributions. Thus, pitch angle resolved energy spectra can be used to determine the plasma source regions sampled by a field line at large distances from the spacecraft. From 12/1/2014 to 2/15/2015, when periapsis was at high northern latitudes, SWEA observed ionospheric photoelectrons at low altitudes (140-200 km) and high solar zenith angles (120-145 degrees) on ~35% of the orbits. Since this electron population is unambiguously produced in the dayside ionosphere, these observations demonstrate that the deep Martian nightside is at times magnetically connected to the sunlit hemisphere. The BATS-R-US Mars multi-fluid MHD model suggests the presence of closed crustal magnetic field lines over the northern hemisphere that straddle the terminator and extend to high SZA. Simulations with the SuperThermal Electron Transport (STET) model show that photoelectron transport along such field lines can take place without significant attenuation. Precipitation of photoelectrons onto the night-side atmosphere should cause ionization and possibly auroral emissions in localized regions. On one orbit, the O2+ energy flux measured by STATIC correlates well with precipitating photoelectron fluxes.

  9. Images of Bottomside Irregularities Observed at Topside Altitudes

    NASA Astrophysics Data System (ADS)

    Gentile, L. C.; Burke, W. J.; Shomo, S. R.; Roddy, P. A.; Pfaff, R. F.

    2011-12-01

    We have analyzed plasma and field measurements acquired by the Communication/ Navigation Outage Forecasting System (C/NOFS) satellite during an eight-hour interval on 13 - 14 January 2010 when strong to moderate 250 MHz scintillation activity was observed at nearby Scintillation Network Decision Aid (SCINDA) ground stations. C/NOFS consistently detected relatively small-scale density and electric field irregularities embedded within large-scale (~100 km) structures at topside altitudes. Significant spectral power measured at the Fresnel (~1 km) scale size suggests that C/NOFS was magnetically conjugate to bottomside irregularities similar to those directly responsible for the observed scintillations. Simultaneous ion drift and plasma density measurements indicate three distinct types of large-scale irregularities: (1) upward moving depletions, (2) downward moving depletions, and (3) upward moving density enhancements. The first type has the characteristics of equatorial plasma bubbles, the second and third do not. The data suggest that both they and embedded small-scale irregularities may be regarded as Alfvénic images of bottomside irregularities. This interpretation is consistent with predictions of previously reported theoretical modeling and with satellite observations of upward directed Poynting flux in the low-latitude ionosphere.

  10. Images of bottomside irregularities observed at topside altitudes

    NASA Astrophysics Data System (ADS)

    Burke, William J.; Gentile, Louise C.; Shomo, Shannon R.; Roddy, Patrick A.; Pfaff, Robert F.

    2012-03-01

    We analyzed plasma and field measurements acquired by the Communication/Navigation Outage Forecasting System (C/NOFS) satellite during an eight-hour period on 13-14 January 2010 when strong to moderate 250 MHz scintillation activity was observed at nearby Scintillation Network Decision Aid (SCINDA) ground stations. C/NOFS consistently detected relatively small-scale density and electric field irregularities embedded within large-scale (˜100 km) structures at topside altitudes. Significant spectral power measured at the Fresnel (˜1 km) scale size suggests that C/NOFS was magnetically conjugate to bottomside irregularities similar to those directly responsible for the observed scintillations. Simultaneous ion drift and plasma density measurements indicate three distinct types of large-scale irregularities: (1) upward moving depletions, (2) downward moving depletions, and (3) upward moving density enhancements. The first type has the characteristics of equatorial plasma bubbles; the second and third do not. The data suggest that both downward moving depletions and upward moving density enhancements and the embedded small-scale irregularities may be regarded as Alfvénic images of bottomside irregularities. This interpretation is consistent with predictions of previously reported theoretical modeling and with satellite observations of upward-directed Poynting flux in the low-latitude ionosphere.

  11. Images of Bottomside Irregularities Observed at Topside Altitudes

    NASA Technical Reports Server (NTRS)

    Burke, William J.; Gentile, Louise C.; Shomo, Shannon R.; Roddy, Patrick A.; Pfaff, Robert F.

    2012-01-01

    We analyzed plasma and field measurements acquired by the Communication/ Navigation Outage Forecasting System (C/NOFS) satellite during an eight-hour period on 13-14 January 2010 when strong to moderate 250 MHz scintillation activity was observed at nearby Scintillation Network Decision Aid (SCINDA) ground stations. C/NOFS consistently detected relatively small-scale density and electric field irregularities embedded within large-scale (approx 100 km) structures at topside altitudes. Significant spectral power measured at the Fresnel (approx 1 km) scale size suggests that C/NOFS was magnetically conjugate to bottomside irregularities similar to those directly responsible for the observed scintillations. Simultaneous ion drift and plasma density measurements indicate three distinct types of large-scale irregularities: (1) upward moving depletions, (2) downward moving depletions, and (3) upward moving density enhancements. The first type has the characteristics of equatorial plasma bubbles; the second and third do not. The data suggest that both downward moving depletions and upward moving density enhancements and the embedded small-scale irregularities may be regarded as Alfvenic images of bottomside irregularities. This interpretation is consistent with predictions of previously reported theoretical modeling and with satellite observations of upward-directed Poynting flux in the low-latitude ionosphere.

  12. Low altitude cloud height and methane humidity retrievals on Titan in the near-IR

    NASA Astrophysics Data System (ADS)

    Adamkovics, M.; Hayes, A.; Mitchell, J.; De Pater, I.; Young, E.

    2013-12-01

    The formation of low altitude clouds on Titan, with cloud-top altitudes below ~10km, likely occurs by a fundamentally different mechanism than for the clouds commonly observed to have cloud-tops in the upper troposphere, above ~15km [1]. Near-infrared spectroscopy of clouds has been the method of choice for determining cloud altitudes [2], however, uncertainties in aerosols scattering properties and opacities, together with limitations in laboratory measurements of gas opacities (in particular for methane), lead to uncertainties in how accurately the altitude of low clouds can be retrieved [3]. Here we revisit near-IR spectra obtained with Keck and Cassini using new laboratory methane line data in the HITRAN 2012 database [4] to address the problem of measuring the altitudes of low clouds. We discuss the role of topography in relation to the formation of low clouds and other diagnostics of conditions near the surface, such as the tropospheric methane humidity. We reanalyze measurements the tropospheric humidity variation [5] and describe observational strategies for improved diagnostics of the tropospheric humidity on Titan . Acknowledgements: Funding for this work is provided by the NSF grant AST-1008788 and NASA OPR grant NNX12AM81G. References: [1] Brown, et al. (2009) ApJ, 706, L110-L113. [2] Ádámkovics et al. (2010) Icarus, 208, 868-877. [3] Griffith et al. (2012) Icarus, 218, 975-988. [4] Rothman et al. (2013) AIP Conf. Proc., 1545, 223-231. [5] Penteado & Griffith (2010) Icarus, 206, 345-351.

  13. Determination of the altitude of the nitric acid layer from very high resolution ground-based IR solar spectra

    NASA Technical Reports Server (NTRS)

    Blatherwick, R. D.; Murcray, F. J.; Murcray, D. G.; Locker, M. H.

    1991-01-01

    A ground-based solar spectrum at a spectral resolution of about 0.002/cm is used to determine the altitude of the HNO3 layer. The 870/cm spectral region, which is essentially free from absorptions from other species, is employed. The data were obtained with the University of Denver 2.5-m maximum path difference Fourier Transform interferometer spectrometer system. A set of 13 HNO3 vertical profiles were used in the analysis. The best fit obtained for the 'starting' profile (which is centered at 24 km), and the best fit for the profile centered at 26 km are shown. For displacements of greater than 2 km, the discrepancy between the synthetic and observed spectra becomes readily discernible by inspection of the spectra. It is shown that the 'best fit' rms residuals are quite sensitive to the assumed altitude of the HNO3 layer.

  14. Progress on low altitude cloud icing research

    NASA Technical Reports Server (NTRS)

    Jeck, R. K.

    1981-01-01

    The icing environment at altitudes below 10,000 feet were studied. The following questions are asked, are: (1) existing aircraft certification criteria applicable; (2) too stringent on icing for helos; (3) based on accurate data; (4) appropriate for low (10,000 ft) altitudes? The research plan is outlined: review historical icing data, obtain new measurements, collect modern icing data from other groups, and recommend LWC, OAT, and MVD criteria for helicopters. Estimated accuracies and known sources of error are included. It is concluded that the net effect of possible sources of error of both signs is uncertain.

  15. Development of a Radio Acoustic Sounding System (RASS) for continuous temperature profiling upto lower stratospheric altitudes

    NASA Astrophysics Data System (ADS)

    Chandrasekhar Sarma, T. V.; Tsuda, Toshitaka

    2012-07-01

    The Gadanki (13.46°N, 79.17°E) MST radar is a high power VHF pulsed coherent Doppler radar established for remote probing of atmospheric phenomena in the Mesosphere Stratosphere Troposphere regions. Radio Acoustic Sounding System (RASS) was developed using this radar to obtain height profiles of atmospheric temperature up to lower stratospheric altitudes. RASS uses the effect of temperature on the speed of sound in air as a means to sense the atmospheric temperature. It is the combination of a Doppler radar and acoustic exciters. The radar was augmented with acoustic exciters that were designed and constructed for this purpose. The Doppler radar profiles the speed of refractive index perturbations induced by the acoustic source. RASS has been demonstrated to be a reliable ground-based remote profiling technique to obtain altitude profiles of atmospheric virtual temperature, Tv over the past two decades. This work describes the design of the system and its application to the observation of height profiles of atmospheric virtual temperature up to and beyond tropical tropopause altitudes. Observations were made during 2007, 2008 and 2009 over periods extending up to 72 hours. These observations demonstrate temperature profiling capability up to about 18 km in altitude, though on an occasion height coverage upto 22.8km was obtained briefly; lowest height covered is from about 1.5km onwards. During the period of the RASS observations simultaneous data from radiosonde was used to validate the temperature measurements. Simultaneous satellite-based measurement of outgoing long wave radiation (OLR) and precipitation from ground-based instruments was used to study the atmospheric phenomena of gravity waves and atmospheric stability during a convection event.

  16. Status Update Report for the Peregrine 100km Sounding Rocket Project

    NASA Technical Reports Server (NTRS)

    Dyer, Jonny; Zilliac, Greg; Doran, Eric; Marzona, Mark Thadeus; Lohner, Kevin; Karlik, Evan; Cantwell, Brian; Karabeyoglu, Arif

    2008-01-01

    The Peregrine Sounding Rocket Program is a joint basic research program of NASA Ames Research Center, NASA Wallops, Stanford University and the Space Propulsion Group, Inc. (SPG). The goal is to determine the applicability of liquifying hybrid technology to a small launch system. The approach is to design, build, test and y a stable, efficient liquefying fuel hybrid rocket vehicle to an altitude of 100 km. The program was kicked o in October of 2006 and has seen considerable progress in the subsequent 18 months. Two virtually identical vehicles will be constructed and own out of the NASA Sounding Rocket Facility at Wallops Island. This paper presents the current status of the project as of June 2008. For background on the project, the reader is referred to last year's paper.

  17. Shuttle high resolution accelerometer package experiment results - Atmospheric density measurements between 60-160 km

    NASA Technical Reports Server (NTRS)

    Blanchard, R. C.; Hinson, E. W.; Nicholson, J. Y.

    1988-01-01

    Indirect or inferred values of atmospheric density encountered by the Shuttle Orbiter during reentry have been calculated from acceleration measurements made by the High Resolution Accelerometer Package (HiRAP) and the Orbiter Inertial Measurement Unit (IMU) liner accelerometers. The atmospheric density data developed from this study represent a significant gain with respect to the body of data collected to date by various techniques in the altitude range of 60 to 160 km. The data are unique in that they cover a very wide horizontal range during each flight and provide insight into the actual density variations encountered along the reentry flight path. The data, which were collected over about 3 years, are also characterized by variations in solar activity, geomagnetic index, and local solar time. Comparison of the flight-derived densities with various atmospheric models have been made, and analyses have attempted to characterize the data and to show correlation with selected physical variables.

  18. Quiet-time plasma irregularities at 1400 km in the cleft region

    NASA Technical Reports Server (NTRS)

    Kayser, S. E.; Maier, E. J.; Brace, L. H.

    1978-01-01

    The quiet north polar cleft at 1400 km was studied by Isis-2 instruments, and data from the retarding potential analyzer and the cylindrical electrostatic probe show that thermal plasma density fluctuations are distributed in a region between 75 deg and 82 deg invariant latitude and approximately dawn to dusk. Cleft shape and shape variations are described. Thermal ions and thermal electrons usually fluctuated together, but suprathermal electrons fluctuated independently. Data on thermal plasma patterns correlates fairly well with observations of soft particles and auroral optical emissions and not as well with measurements of high-energy particles. The data suggest that the energy source for the thermal irregularities is associated with soft particles and that precipitating high-energy particles do not drive the thermal plasma at these altitudes.

  19. Study on the performance of electromagnetic particle detectors of LHAASO-KM2A

    NASA Astrophysics Data System (ADS)

    Zhang, Zhongquan; Hou, Chao; Cao, Zhen; Chang, Jingfan; Feng, Cunfeng; Hanapia, Erlan; Gong, Guanghua; Liu, Jia; Lv, Hongkui; Sheng, Xiangdong; Zhang, Shaoru; Zhu, Chengguang

    2017-02-01

    The electromagnetic particle detectors (EDs) for one square kilometer detector array (KM2A) of large high altitude air shower observation (LHAASO) are designed to measure the densities and arrival times of secondary particles in extensive air showers (EASs). ED is a type of plastic scintillator detector with an active area of 1 m2. This study investigates the design and performance of prototype ED. Approximately 20 photoelectrons are collected by the 1st dynode of a photomultiplier tube (PMT). The prototype ED exhibited good detection efficiency and time resolution. The detection for the wide dynamic particle density varying from 1 to 10 000 particles/m2 is realized with the design of the PMT divider for the readout of both the anode and 6th dynode.

  20. Pioneer Venus 12.5 km Anomaly Workshop Report, volume 1

    NASA Technical Reports Server (NTRS)

    Seiff, A.; Sromovsky, L.; Borucki, W.; Craig, R.; Juergens, D.; Young, R. E.; Ragent, B.

    1995-01-01

    A workshop was convened at Ames Research Center on September 28 and 29, 1993, to address the unexplained electrical anomalies experienced in December 1978 by the four Pioneer Venus probes below a Venus altitude of 12.5 km. These anomalies caused the loss of valuable data in the deep atmosphere, and, if their cause were to remain unexplained, could reoccur on future Venus missions. The workshop participants reviewed the evidence and studied all identified mechanisms that could consistently account for all observed anomalies. Both hardware problems and atmospheric interactions were considered. Based on a workshop recommendation, subsequent testing identified the cause as being an insulation failure of the external harness. All anomalous events are now explained.

  1. Variability in low altitude astronomical refraction as a function of altitude.

    PubMed

    Sampson, Russell D; Lozowski, Edward P; Fathi-Nejad, Arsha

    2008-12-01

    Low altitude astronomical refraction (LAAR) of the setting Sun was measured over a sea horizon from a coastal location in Barbados, West Indies. The altitude of the upper limb of the Sun and the apparent horizon were determined using a digital video camera (Canon XL2) and a digital SLR camera (Canon EOS 5D). A total of 14 sunsets were measured between 2005 and 2007. From these measurements LAAR variability was estimated at 14 standard altitudes of the refracted Sun between 0 degrees .01 and 4 degrees .5. The relative variability decreases with increasing altitude from +/- 0.0195 of mean refraction at an altitude of 0 degrees .01 to +/- 0.0142 at 4 degrees .5. If extrapolated to an altitude of 15 degrees , a linear fit to the data produces a relative variability of +/- 0.0038 and an absolute variability of +/- 0(").45. Statistical analysis of the relative variability in LAAR appears to support the decreasing trend. However, error propagation analysis further suggests that the observed values of refraction may exceed the accuracy of the measurement system at altitudes higher than 2 degrees .

  2. Altitude variations in the thermosphere mass density response to geomagnetic activity during the recent solar minimum

    NASA Astrophysics Data System (ADS)

    Liu, X.; Thayer, J. P.; Burns, A.; Wang, W.; Sutton, E.

    2014-03-01

    Accelerometer data from coplanar orbits of Challenging Minisatellite Payload (CHAMP) and Gravity Recovery and Climate Experiment (GRACE) satellites were used to study the complex altitude and latitude variations of the thermosphere mass density response to geomagnetic activity during 1-10 December 2008 near 09 LT. Helium number densities near 500 km altitude were extracted from the CHAMP and GRACE measurements and clearly show the presence of a winter hemisphere helium bulge. This recent extreme solar minimum indicates that wintertime helium concentrations exceed NRLMSISE-00 model estimates by 30%-70% during quiet geomagnetic activity after adjusting F10.7 input into MSIS. The perturbation in mass density from quiet to active conditions is found to be less enhanced in the winter hemisphere at the higher GRACE altitudes (25%) than at the lower CHAMP altitudes (60%) and is attributed to dynamic behavior in the helium/oxygen transition. The investigation revealed the maximum storm time density perturbation to occur near the He/O transition region with a much weaker maximum near the O/N2 transition region. The altitude of maximum density perturbation occurs where the perturbation in the weighted pressure scale height is equal and opposite to the perturbation in the weighted mean molecular weight scale height. The altitude structure of density scale height perturbation is significantly influenced by the changes in the molecular weight scale height and can account for 50% of the change in mass density scale height in a region correspondingly close to the He/O transition during the 2008 solar minimum period.

  3. Comparing the contributions of ionospheric outflow and high-altitude production to O+ loss at Mars

    NASA Astrophysics Data System (ADS)

    Liemohn, Michael; Curry, Shannon; Fang, Xiaohua; Johnson, Blake; Fraenz, Markus; Ma, Yingjuan

    2013-04-01

    The Mars total O+ escape rate is highly dependent on both the ionospheric and high-altitude source terms. Because of their different source locations, they appear in velocity space distributions as distinct populations. The Mars Test Particle model is used (with background parameters from the BATS-R-US magnetohydrodynamic code) to simulate the transport of ions in the near-Mars space environment. Because it is a collisionless model, the MTP's inner boundary is placed at 300 km altitude for this study. The MHD values at this altitude are used to define an ionospheric outflow source of ions for the MTP. The resulting loss distributions (in both real and velocity space) from this ionospheric source term are compared against those from high-altitude ionization mechanisms, in particular photoionization, charge exchange, and electron impact ionization, each of which have their own (albeit overlapping) source regions. In subsequent simulations, the MHD values defining the ionospheric outflow are systematically varied to parametrically explore possible ionospheric outflow scenarios. For the nominal MHD ionospheric outflow settings, this source contributes only 10% to the total O+ loss rate, nearly all via the central tail region. There is very little dependence of this percentage on the initial temperature, but a change in the initial density or bulk velocity directly alters this loss through the central tail. However, a density or bulk velocity increase of a factor of 10 makes the ionospheric outflow loss comparable in magnitude to the loss from the combined high-altitude sources. The spatial and velocity space distributions of escaping O+ are examined and compared for the various source terms, identifying features specific to each ion source mechanism. These results are applied to a specific Mars Express orbit and used to interpret high-altitude observations from the ion mass analyzer onboard MEX.

  4. Reducing body fat with altitude hypoxia training in swimmers: role of blood perfusion to skeletal muscles.

    PubMed

    Chia, Michael; Liao, Chin-An; Huang, Chih-Yang; Lee, Wen-Chih; Hou, Chien-Wen; Yu, Szu-Hsien; Harris, M Brennan; Hsu, Tung-Shiung; Lee, Shin-Da; Kuo, Chia-Hua

    2013-02-28

    Swimmers tend to have greater body fat than athletes from other sports. The purpose of the study was to examine changes in body composition after altitude hypoxia exposure and the role of blood distribution to the skeletal muscle in swimmers. With a constant training volume of 12.3 km/day, young male swimmers (N = 10, 14.8 ± 0.5 years) moved from sea-level to a higher altitude of 2,300 meters. Body composition was measured before and after translocation to altitude using dual-energy X-ray absorptiometry (DXA) along with 8 control male subjects who resided at sea level for the same period of time. To determine the effects of hypoxia on muscle blood perfusion, total hemoglobin concentration (THC) was traced by near-infrared spectroscopy (NIRS) in the triceps and quadriceps muscles under glucose-ingested and insulin-secreted conditions during hypoxia exposure (16% O2) after training. While no change in body composition was found in the control group, subjects who trained at altitude had unequivocally decreased fat mass (-1.7 ± 0.3 kg, -11.4%) with increased lean mass (+0.8 ± 0.2 kg, +1.5%). Arterial oxygen saturation significantly decreased with increased plasma lactate during hypoxia recovery mimicking 2,300 meters at altitude (~93% versus ~97%). Intriguingly, hypoxia resulted in elevated muscle THC, and sympathetic nervous activities occurred in parallel with greater-percent oxygen saturation in both muscle groups. In conclusion, the present study provides evidence that increased blood distribution to the skeletal muscle under postprandial condition may contribute to the reciprocally increased muscle mass and decreased body mass after a 3-week altitude exposure in swimmers.

  5. High altitude bird migration at temperate latitudes: a synoptic perspective on wind assistance.

    PubMed

    Dokter, Adriaan M; Shamoun-Baranes, Judy; Kemp, Michael U; Tijm, Sander; Holleman, Iwan

    2013-01-01

    At temperate latitudes the synoptic patterns of bird migration are strongly structured by the presence of cyclones and anticyclones, both in the horizontal and altitudinal dimensions. In certain synoptic conditions, birds may efficiently cross regions with opposing surface wind by choosing a higher flight altitude with more favourable wind. We observed migratory passerines at mid-latitudes that selected high altitude wind optima on particular nights, leading to the formation of structured migration layers at varying altitude up to 3 km. Using long-term vertical profiling of bird migration by C-band Doppler radar in the Netherlands, we find that such migration layers occur nearly exclusively during spring migration in the presence of a high-pressure system. A conceptual analytic framework providing insight into the synoptic patterns of wind assistance for migrants that includes the altitudinal dimension has so far been lacking. We present a simple model for a baroclinic atmosphere that relates vertical profiles of wind assistance to the pressure and temperature patterns occurring at temperate latitudes. We show how the magnitude and direction of the large scale horizontal temperature gradient affects the relative gain in wind assistance that migrants obtain through ascending. Temperature gradients typical for northerly high-pressure systems in spring are shown to cause high altitude wind optima in the easterly sectors of anticyclones, thereby explaining the frequent observations of high altitude migration in these synoptic conditions. Given the recurring synoptic arrangements of pressure systems across temperate continents, the opportunities for exploiting high altitude wind will differ between flyways, for example between easterly and westerly oceanic coasts.

  6. 2005 Annual Operations Report for INTEC Operable Unit 3-13, Group 1, Tank Farm Interim Action

    SciTech Connect

    D. Shanklin

    2006-07-19

    This annual operations report describes the requirements followed and activities conducted to inspect, monitor, and maintain the items installed during performance of the Waste Area Group 3, Operable Unit 3-13, Group 1, Tank Farm Interim Action, at the Idaho Nuclear Technology and Engineering Center. This report describes inspection and monitoring activities fro the surface-sealed areas within the tank farm, concrete-lined ditches and culverts in and around the tank farm, the lift station, and the lined evaporation pond. These activities are intended to assure that the interim action is functioning adequately to meet the objectives stated in the Operable Unit 3-13, Record of Decision for the Group 1, Tank Farm Interim Action, (DOE/ID-10660) and as amended by the agreement to resolve dispute, which was effective in February 2003.

  7. 2006 Annual Operations Report for INTEC Operable Unit 3-13, Group 1, Tank Farm Interim Action

    SciTech Connect

    D. E. Shanklin

    2007-02-14

    This annual operations report describes the requirements followed and activities conducted to inspect, monitor, and maintain the items installed during performance of the Waste Area Group 3, Operable Unit 3-13, Group 1, Tank Farm Interim Action, at the Idaho Nuclear Technology and Engineering Center. This report covers the time period from January 1 through December 31, 2006, and describes inspection and monitoring activities for the surface-sealed areas within the tank farm, concrete-lined ditches and culverts in and around the tank farm, the lift station, and the lined evaporation pond. These activities are intended to assure that the interim action is functioning adequately to meet the objectives stated in the Operable Unit 3-13, Record of Decision for the Group 1, Tank Farm Interim Action (DOE/ID-10660) as described in the Group 1 Remedial Design/Remedial Action Work Plan (DOE/ID-10772).

  8. Dietary Recommendations for Cyclists during Altitude Training.

    PubMed

    Michalczyk, Małgorzata; Czuba, Miłosz; Zydek, Grzegorz; Zając, Adam; Langfort, Józef

    2016-06-18

    The concept of altitude or hypoxic training is a common practice in cycling. However, several strategies for training regimens have been proposed, like "live high, train high" (LH-TH), "live high, train low" (LH-TL) or "intermittent hypoxic training" (IHT). Each of them combines the effect of acclimatization and different training protocols that require specific nutrition. An appropriate nutrition strategy and adequate hydration can help athletes achieve their fitness and performance goals in this unfriendly environment. In this review, the physiological stress of altitude exposure and training will be discussed, with specific nutrition recommendations for athletes training under such conditions. However, there is little research about the nutrition demands of athletes who train at moderate altitude. Our review considers energetic demands and body mass or body composition changes due to altitude training, including respiratory and urinary water loss under these conditions. Carbohydrate intake recommendations and hydration status are discussed in detail, while iron storage and metabolism is also considered. Last, but not least the risk of increased oxidative stress under hypoxic conditions and antioxidant supplementation suggestions are presented.

  9. High-altitude physiology: lessons from Tibet

    NASA Astrophysics Data System (ADS)

    Wagner, Peter D.; Simonson, Tatum S.; Wei, Guan; Wagner, Harrieth; Wuren, Tanna; Yan, Ma; Qin, Ga; Ge, Rili

    2013-05-01

    Polycythemia is a universal lowlander response to altitude; healthy Andean high-altitude natives also have elevated [Hb]. While this may enhance O2 transport to tissues, studies have shown that acute isovolumic changes in [Hb] do not affect exercise capacity. Many high-altitude Tibetans have evolved sea-level values of [Hb], providing a natural opportunity to study this issue. In 21 young healthy male Tibetans with [Hb] between 15 and 23 g/dl, we measured VO2MAX and O2 transport capacity at 4200m. VO2MAX was higher when [Hb] was lower (P<0.05), enabled by both higher cardiac output and muscle O2 diffusional conductance, but neither ventilation nor the alveolar-arterial PO2 difference (AaPO2) varied with [Hb]. In contrast, Andean high altitude natives remain polycythemic with larger lungs and higher lung diffusing capacity, a smaller exercising AaPO2, and lower ventilation. The challenges now are (1) to understand the different adaptive pathways used by Andeans and Tibetans, and (2) to determine in Tibetans whether, during evolution, reduced [Hb] appeared first, causing compensatory cardiac and muscle adaptations, or if enhanced cardiac function and muscle O2 transport capacity appeared first, permitting secondary reduction in [Hb]. For (2), further research is necessary to determine the basis of enhanced cardiac function and muscle O2 transport, and identify molecular targets of evolution in heart and muscle. Putative mutations can then be timed and compared to appearance of those affecting [Hb].

  10. Altitude Preexposure Recommendations for Inducing Acclimatization

    DTIC Science & Technology

    2010-01-01

    acetazolamide ( Kronenberg and Cain, 1968). Acute exposure to high altitude increases heart rate and cardiac output to maintain systemic oxygen delivery...emphasizing the regulation of breathing. Physiologist. 11:37–57. Kronenberg R.S., and Cain S.M. (1968). Hastening respiratory acclimatization to

  11. Breathing and sleep at high altitude.

    PubMed

    Ainslie, Philip N; Lucas, Samuel J E; Burgess, Keith R

    2013-09-15

    We provide an updated review on the current understanding of breathing and sleep at high altitude in humans. We conclude that: (1) progressive changes in pH initiated by the respiratory alkalosis do not underlie early (<48 h) ventilatory acclimatization to hypoxia (VAH) because this still proceeds in the absence of such alkalosis; (2) for VAH of longer duration (>48 h), complex cellular and neurochemical re-organization occurs both in the peripheral chemoreceptors as well as within the central nervous system. The latter is likely influenced by central acid-base changes secondary to the extent of the initial respiratory responses to initial exposure to high altitude; (3) sleep at high altitude is disturbed by various factors, but principally by periodic breathing; (4) the extent of periodic breathing during sleep at altitude intensifies with duration and severity of exposure; (5) complex interactions between hypoxic-induced enhancement in peripheral and central chemoreflexes and cerebral blood flow--leading to higher loop gain and breathing instability--underpin this development of periodic breathing during sleep; (6) because periodic breathing may elevate rather than reduce mean SaO2 during sleep, this may represent an adaptive rather than maladaptive response; (7) although oral acetazolamide is an effective means to reduce periodic breathing by 50-80%, recent studies using positive airway pressure devices to increase dead space, hyponotics and theophylline are emerging but appear less practical and effective compared to acetazolamide. Finally, we suggest avenues for future research, and discuss implications for understanding sleep pathology.

  12. The Power of Aircraft Engines at Altitude

    NASA Technical Reports Server (NTRS)

    Ragazzi, Paolo

    1939-01-01

    The subject of the present paper is confined to the investigations and methods employed by the Fiat company in their studies on the altitude performance of an air-cooled engine of the production type. The experimental set-up as well as test engine data are provided.

  13. SRB Altitude Switch Assembly Wire Harness Failure

    NASA Technical Reports Server (NTRS)

    Blanche, Jim

    2002-01-01

    This paper presents an assessment of two wire harness failures that had occurred in Solid Rocket Booster Altitude Switch Assemblies S/N 200001 and S/N 20002. A list of modifications to EDU #4 and modification of qualification units 2000001 and 2000002 are also presented.

  14. Dietary Recommendations for Cyclists during Altitude Training

    PubMed Central

    Michalczyk, Małgorzata; Czuba, Miłosz; Zydek, Grzegorz; Zając, Adam; Langfort, Józef

    2016-01-01

    The concept of altitude or hypoxic training is a common practice in cycling. However, several strategies for training regimens have been proposed, like “live high, train high” (LH-TH), “live high, train low” (LH-TL) or “intermittent hypoxic training” (IHT). Each of them combines the effect of acclimatization and different training protocols that require specific nutrition. An appropriate nutrition strategy and adequate hydration can help athletes achieve their fitness and performance goals in this unfriendly environment. In this review, the physiological stress of altitude exposure and training will be discussed, with specific nutrition recommendations for athletes training under such conditions. However, there is little research about the nutrition demands of athletes who train at moderate altitude. Our review considers energetic demands and body mass or body composition changes due to altitude training, including respiratory and urinary water loss under these conditions. Carbohydrate intake recommendations and hydration status are discussed in detail, while iron storage and metabolism is also considered. Last, but not least the risk of increased oxidative stress under hypoxic conditions and antioxidant supplementation suggestions are presented. PMID:27322318

  15. The morbid anatomy of high altitude

    PubMed Central

    Heath, Donald

    1979-01-01

    The morbid anatomical changes which take place in man and animals exposed to the chronic hypoxia of residence at high altitude are briefly reviewed. ImagesFig. 1Fig. 2Fig. 3Fig. 5Fig. 4Fig. 6Fig. 7Fig. 8 PMID:493205

  16. Sickle Cell Trait, Exercise, and Altitude.

    ERIC Educational Resources Information Center

    Eichner, Edward R.

    1986-01-01

    Sickle cell trait is generally benign and does not shorten life, but it may confer some small risk with extremes of exercise or altitude. Research concerning these risks is presented, and it is concluded sickle cell trait is no barrier to outstanding athletic performance. (Author/MT)

  17. Sextant measures spacecraft altitude without gravitational reference

    NASA Technical Reports Server (NTRS)

    1966-01-01

    Horizon-sensing sextant measures the altitude of an orbiting spacecraft without gravitational reference by optically measuring the dip angle to the horizon along a line of sight in each of two planes. The sextant scans over a relatively limited field of view.

  18. Altitude Adaptation: A Glimpse Through Various Lenses

    PubMed Central

    2015-01-01

    Abstract Simonson, Tatum S. Altitude adaptation: A glimpse through various lenses. High Alt Med Biol 16:125–137, 2015.—Recent availability of genome-wide data from highland populations has enabled the identification of adaptive genomic signals. Some of the genomic signals reported thus far among Tibetan, Andean, and Ethiopian are the same, while others appear unique to each population. These genomic findings parallel observations conveyed by decades of physiological research: different continental populations, resident at high altitude for hundreds of generations, exhibit a distinct composite of traits at altitude. The most commonly reported signatures of selection emanate from genomic segments containing hypoxia-inducible factor (HIF) pathway genes. Corroborative evidence for adaptive significance stems from associations between putatively adaptive gene copies and sea-level ranges of hemoglobin concentration in Tibetan and Amhara Ethiopians, birth weights and metabolic factors in Andeans and Tibetans, maternal uterine artery diameter in Andeans, and protection from chronic mountain sickness in Andean males at altitude. While limited reports provide mechanistic insights thus far, efforts to identify and link precise genetic variants to molecular, physiological, and developmental functions are underway, and progress on the genomics front continues to provide unprecedented movement towards these goals. This combination of multiple perspectives is necessary to maximize our understanding of orchestrated biological and evolutionary processes in native highland populations, which will advance our understanding of both adaptive and non-adaptive responses to hypoxia. PMID:26070057

  19. [High altitude anemia: validity of definition criteria].

    PubMed

    Yepez, R; Estevez, E; Galan, P; Chauliac, M; Davila, M; Calle, A; Estrella, R; Masse-Raimbault, A M; Hercberg, S

    1994-01-01

    The effect of iron and folate supplementation on the hemoglobin response and iron status was studied in male and female equatorian medical students: 66 in Quito (2,800 m altitude) and 40 in Guayaquil (sea level). At the end of the supplementation, there was a nearly complete disappearance of biochemical evidence of iron deficiency in the two groups of students. In Quito, 30% of the men and 26% of the women increased their hemoglobin concentration by more than 1 g/dl after one month of supplementation and could be considered as true anemics, compared to 31% of the men and 29% of the women in Guayaquil. This study shows that at sea level, cut-off points defined by WHO for hemoglobin, taking as reference the impact of a supplementation trial, have a specificity of 100% but poor sensitivity (58%). For people living at high altitudes, cut-off limits adjusted for altitude seem unsuitable: the specificity is 98% but the sensitivity is 0%. Studies taking into account all the factors impacting on the hemoglobin level could be useful for defining cut-off points for high-altitude anemia better than those currently recommended.

  20. Performance of portable ventilators at altitude

    DTIC Science & Technology

    2015-04-20

    BirdVSO2 and theLTV- 1000 at ranges of altitudes from sea level to 9,800 ft using lung models of adult respiratory distress syndrome and severe asthma ...Trauma. 2010;69(6):1574Y1577. 11. Tourtier JP, Forsans E, Leclerc T, Libert N, Ramsang S, Tazarourte K, Man M, Borne M. Acute severe asthma : performance

  1. Altitude Adaptation: A Glimpse Through Various Lenses.

    PubMed

    Simonson, Tatum S

    2015-06-01

    Simonson, Tatum S. Altitude adaptation: A glimpse through various lenses. High Alt Med Biol 16:125-137, 2015.--Recent availability of genome-wide data from highland populations has enabled the identification of adaptive genomic signals. Some of the genomic signals reported thus far among Tibetan, Andean, and Ethiopian are the same, while others appear unique to each population. These genomic findings parallel observations conveyed by decades of physiological research: different continental populations, resident at high altitude for hundreds of generations, exhibit a distinct composite of traits at altitude. The most commonly reported signatures of selection emanate from genomic segments containing hypoxia-inducible factor (HIF) pathway genes. Corroborative evidence for adaptive significance stems from associations between putatively adaptive gene copies and sea-level ranges of hemoglobin concentration in Tibetan and Amhara Ethiopians, birth weights and metabolic factors in Andeans and Tibetans, maternal uterine artery diameter in Andeans, and protection from chronic mountain sickness in Andean males at altitude. While limited reports provide mechanistic insights thus far, efforts to identify and link precise genetic variants to molecular, physiological, and developmental functions are underway, and progress on the genomics front continues to provide unprecedented movement towards these goals. This combination of multiple perspectives is necessary to maximize our understanding of orchestrated biological and evolutionary processes in native highland populations, which will advance our understanding of both adaptive and non-adaptive responses to hypoxia.

  2. Safely Enabling Low-Altitude Airspace Operations

    NASA Technical Reports Server (NTRS)

    Kopardekar, Parimal

    2015-01-01

    Near-term Goal: Enable initial low-altitude airspace and UAS operations with demonstrated safety as early as possible, within 5 years. Long-term Goal: Accommodate increased UAS operations with highest safety, efficiency, and capacity as much autonomously as possible (10-15 years).

  3. Coherent scatter radar observations of 150-km echoes and vertical plasma drifts in the Brazilian sector

    NASA Astrophysics Data System (ADS)

    Rodrigues, F. S.; de Paula, E. R.; Hysell, D. L.; Chau, J. L.

    2008-12-01

    Coherent scatter echoes coming from the valley region (~150 km altitude) in the equatorial ionosphere during daytime have been detected by the Jicamarca radar in Peru for several decades (Basley, 1945). More recently, it was found that the vertical Doppler shift of these echoes corresponds to the vertical velocity of the F-region background plasma (Kudeki and Fawcett, 1993; Woodman and Villanueva,1995, Chau and Woodman, 2004). Jicamarca now uses observations of 150-km echoes to provide estimates of the diurnal variation of the equatorial vertical plasma drifts in addition to traditional incoherent scatter radar drift measurements. These 150-km echoes have also been observed in other longitude sectors (e.g. Tsunoda and Ecklund,2004; Patra et al., 2008). Additionally, these echoes have also been detected in a semi-routine basis with a small, low-power radar in Sao Luis, Brazil. Initial results of our analysis suggest that vertical plasma drifts can be estimated from these observations. These measurements combined with simultaneous measurements made by the Jicamarca radar and the C/NOFS satellite can help us better understand the day-to-day variability and longitudinal variation of equatorial electric fields. In this talk we will present examples of 150-km echoes observations made with the Sao Luis radar. We will describe how vertical drifts can be estimated from the observations and how the vertical drifts over Sao Luis compare with the drifts measured simultaneously at Jicamarca. These new measurements can provide important new information about the low-latitude electrodynamics, and consequently to the C/NOFS mission.

  4. Mini review of high altitude health problems in Ladakh.

    PubMed

    Norboo, T; Saiyed, H N; Angchuk, P T; Tsering, P; Angchuk, S T; Phuntsog, S T; Yahya, M; Wood, Steve; Bruce, N G; Ball, K P

    2004-05-01

    Ladakh is a sparsely populated area of Indian Himalaya lying at 3-4500 m altitude mainly consisting of arid desert. This paper will discuss high altitude health problems in Ladakh under the following headings. 1. Acute altitude illness: acute mountain sickness (AMS), high altitude pulmonary edema (HAPE) and high altitude cerebral edema (HACE). 2. Effects of prolonged and permanent exposure to high altitude: (subacute and chronic mountain sickness). 3. Environmental dust and domestic fire pollution resulting in non-occupational pneumoconiosis and high prevalence of respiratory morbidity.

  5. Is high altitude pulmonary edema relevant to Hawai'i?

    PubMed

    Cornell, Seth Lewis

    2014-11-01

    High altitude clinical syndromes have been described in the medical literature but may be under recognized in the state of Hawai'i. As tourism increases, high altitude injuries may follow given the easy access to high altitude attractions. Visitors and clinicians should be aware of the dangers associated with the rapid ascent to high altitudes in the perceived comfort of a vehicle. This paper will review the basic pathophysiology, prevention, and treatment of the most serious of the high altitude clinical syndromes, high altitude pulmonary edema.

  6. Is High Altitude Pulmonary Edema Relevant to Hawai‘i?

    PubMed Central

    2014-01-01

    High altitude clinical syndromes have been described in the medical literature but may be under recognized in the state of Hawai‘i. As tourism increases, high altitude injuries may follow given the easy access to high altitude attractions. Visitors and clinicians should be aware of the dangers associated with the rapid ascent to high altitudes in the perceived comfort of a vehicle. This paper will review the basic pathophysiology, prevention, and treatment of the most serious of the high altitude clinical syndromes, high altitude pulmonary edema. PMID:25478294

  7. Cone structure and focusing of VLF and LF electromagnetic waves at high altitudes in the ionosphere

    NASA Technical Reports Server (NTRS)

    Alpert, Ya. L.; Green, J. L.

    1994-01-01

    The frequency and angle dependencies of the electric field radiated by an electric dipole E = E(sub 0) cos omega(t) are studied through numerical calculations of absolute value of E in the VLF and LF frequency bands where F is less than or equal 0.02 to 0.05 f(sub b) in a model ionosphere over an altitude region of 800-6000 km where the wave frequency and electron gyrofrequency varies between F approximately 4-500 kHz and f(sub b) is approximately equal (1.1 to 0.2) MHz respectively. It is found that the amplitudes of the electric field have large maxima in four regions: close to the direction of the Earth magnetic field line B(sub 0) (it is called the axis field E(sub 0), in the Storey E(sub St), reversed Storey E(sub RevSt), and resonance E(sub Res) cones. The maximal values of E(sub 0), E(sub Res), and E(sub RevSt) are the most pronounced close to the lower hybrid frequency, F approximately F(sub L). The flux of the electric field is concentrated in very narrow regions, with the apex angles of the cones Delta-B is approximately (0.1-1) deg. The enhancement and focusing of the electric field increases with altitude starting at Z greater than 800 km. At Z greater than or equal to 1000 up to 6000 km, the relative value of absolute value of E, in comparison with its value at Z = 800 km is about (10(exp 2) to 10(exp 4)) times larger. Thus the flux of VLF and LF electromagnetic waves generated at high altitudes in the Earth's ionosphere are trapped into very narrow conical beams similar to laser beams.

  8. A High-Altitude Search for Vulcanoids: Progress Report

    NASA Astrophysics Data System (ADS)

    Durda, D. D.; Stern, S. A.; Terrell, D. C.; Weidenschilling, S. J.

    2002-09-01

    We are conducting a unique, high-altitude observing campaign to search for vulcanoids, a population of small, asteroid-like bodies hypothesized to reside in the dynamically stable region interior to Mercury's orbit (i.e., orbits with aphelia <0.21 AU). This airborne search campaign utilizes our versatile and highly capable SWUIS-A (Southwest Universal Imaging System - Airborne) instrument flown with the flight astronomer (SAS and DDD) to an altitude of 49,000 MSL aboard NASA F/A-18B aircraft in order to obtain darker twilight conditions for near-Sun observing than are possible from the ground. The first observing run was successfully completed at NASA's Dryden Flight Research Center during the March/April 2002 vernal equinox observing opportunity. On each of the three evening flights we recorded image data covering 250 square degrees of sky centered on the ecliptic from solar elongations of 6-18 deg. Initial reduction of portions of the Mar/Apr 2002 data set demonstrates that we are reliably detecting objects to magnitude V = 9.5 at 15 degrees solar elongation. This is at least a magnitude fainter than the best previous ground-based searches and comparable to the faintest stars visible in our space-based SOHO LASCO C3 coronagraph vulcanoids search. The SWUIS-A instrument itself is capable of imaging objects as faint as magnitude V = 13, corresponding to vulcanoids less than 10 km across, with a sufficiently dark sky background; we are working to mitigate sky background brightness to reach these deeper magnitude limits for a second F/A-18B observing run during the September 2002 autumnal equinox observing opportunity. We thank NASA research pilots Rick Searfoss, Dana Purifoy, and Craig Bomben. This research is supported by the NASA Planetary Astronomy program, NASA's Dryden Flight Research Center, and the National Geographic Society.

  9. The effect of sudden depressurization on pilots at cruising altitude.

    PubMed

    Muehlemann, Thomas; Holper, Lisa; Wenzel, Juergen; Wittkowski, Martin; Wolf, Martin

    2013-01-01

    The standard flight level for commercial airliners is ∼12 km (40 kft; air pressure: ∼ 200 hPa), the maximum certification altitude of modern airliners may be as high as 43-45 kft. Loss of structural integrity of an airplane may result in sudden depressurization of the cabin potentially leading to hypoxia with loss of consciousness of the pilots. Specialized breathing masks supply the pilots with oxygen. The aim of this study was to experimentally simulate such sudden depressurization to maximum design altitude in a pressure chamber while measuring the arterial and brain oxygenation saturation (SaO(2) and StO(2)) of the pilots. Ten healthy subjects with a median age of 50 (range 29-70) years were placed in a pressure chamber, breathing air from a cockpit mask. Pressure was reduced from 753 to 148 hPa within 20 s, and the test mask was switched to pure O(2) within 2 s after initiation of depressurization. During the whole procedure SaO(2) and StO(2) were measured by pulse oximetry, respectively near-infrared spectroscopy (NIRS; in-house built prototype) of the left frontal cortex. During the depressurization the SaO(2) dropped from median 93% (range 91-98%) to 78% (62-92%) by 16% (6-30%), while StO(2) decreased from 62% (47-67%) to 57% (43-62%) by 5% (3-14%). Considerable drops in oxygenation were observed during sudden depressurization. The inter-subject variability was high, for SaO(2) depending on the subjects' ability to preoxygenate before the depressurization. The drop in StO(2) was lower than the one in SaO(2) maybe due to compensation in blood flow.

  10. High-altitude structure of the magnetic anomalies using the gradient measurements in stratosphere

    NASA Astrophysics Data System (ADS)

    Tsvetkov, Yu.; Rotanova, N.; Belikova, M.

    2003-04-01

    HIGH-ALTITUDE STRUCTURE OF THE MAGNETIC ANOMALIES USING THE GRADIENT MEASUREMENTS IN STRATOSPHERE Yu. Tsvetkov, N. ROTANOVA, M. Belikova Institute of Terrestrial Magnetism, Ionosphere and Radio Wave Propagation RAS, Troitsk, Moscow Region, 142190, Russia rotanova@izmiran.rssi.ru/FAX: +7-095-3340124 Method of the recalculation of the anomaly magnetic field over the range of the altitudes of 20-40 km is suggested. Technique is based on the experimental data of the anomaly magnetic field, its vertical gradient and the gradient increment along vertical line, obtained from the aerostat gradient magnetic surveys in stratosphere. The high-altitude structure of the magnetic anomalies, obtained for the Baikal region has been constructed. These results were used to obtain the estimations of the deep magnetic sources. The numerous values of the low boundary of the sources are 30-35 km. These estimations of the depth coincide with the ones, obtained from the results of the spectral analysis of the same magnetic anomalies.

  11. A comparison of measured and calculated upwelling radiance over water as a function of sensor altitude

    NASA Technical Reports Server (NTRS)

    Coney, T. A.; Salzman, J. A.

    1979-01-01

    A comparison is made between remote sensing data measured over water at altitudes ranging from 30 m to 15.2 km and data calculated for corresponding altitudes using surface measurements and an atmospheric radiative transfer model. Data were acquired on June 22, 1978 in Lake Erie, a cloudless, calm, near haze free day. Suspended solids and chlorophyll concentrations were 0.59 + or - 0.02 mg/1 and 2.42 + or - 0.03 micrograms/1 respectively throughout the duration of the experiment. Remote sensor data were acquired by two multispectral scanners each having 10 bands between 410 nm and 1040 nm. Calculated and measured nadir radiances for altitudes of 152 m and 12.5 km agree to within 16% and 14% respectively. The variation in measured radiance with look angle was poorly simulated by the model. It was concluded that an accurate assessment of the source of error will require the inclusion in the analysis of the contributions made by the sea state and specular sky reflectance.

  12. Ionospheric ion composition from satellite measurements made during 1970-1980 - Altitude profiles

    NASA Technical Reports Server (NTRS)

    Hoegy, W. R.; Grebowsky, J. M.; Brace, L. H.

    1991-01-01

    Ion-mass spectrometers were carried by a number of satellites in the 1970s. The ion-composition measurements from two of these missions, the Orbiting Geophysical Observatory-6 and the Atmosphere Explorer-C, are collected into an ion composition data base to evaluate several widely used empirical and theoretical models for the species H(+), He(+), N(+), O(+), NO(+), N2(+), and O2(+). The data base covers all latitudes and local times, and the altitude range from 150 km to 1200 km, but here altitude plots are presented of the ion densities at noon and at dip latitudes of 20-40 deg N. The satellite data are compared with an early ion-density profile, with the Koehnlein and IRI-90 empirical models, and with the Utah State University theoretical ionosphere model. These comparisons serve to verify some aspects of the models, but they also reveal some outstanding differences. The solar activity dependence of H(+), He(+), N(+), and O(+) is demonstrated, although this has not been possible for the molecular ions because low altitude measurements have not been made near solar maximum.

  13. The paradox of extreme high-altitude migration in bar-headed geese Anser indicus

    PubMed Central

    Hawkes, L. A.; Balachandran, S.; Batbayar, N.; Butler, P. J.; Chua, B.; Douglas, D. C.; Frappell, P. B.; Hou, Y.; Milsom, W. K.; Newman, S. H.; Prosser, D. J.; Sathiyaselvam, P.; Scott, G. R.; Takekawa, J. Y.; Natsagdorj, T.; Wikelski, M.; Witt, M. J.; Yan, B.; Bishop, C. M.

    2013-01-01

    Bar-headed geese are renowned for migratory flights at extremely high altitudes over the world's tallest mountains, the Himalayas, where partial pressure of oxygen is dramatically reduced while flight costs, in terms of rate of oxygen consumption, are greatly increased. Such a mismatch is paradoxical, and it is not clear why geese might fly higher than is absolutely necessary. In addition, direct empirical measurements of high-altitude flight are lacking. We test whether migrating bar-headed geese actually minimize flight altitude and make use of favourable winds to reduce flight costs. By tracking 91 geese, we show that these birds typically travel through the valleys of the Himalayas and not over the summits. We report maximum flight altitudes of 7290 m and 6540 m for southbound and northbound geese, respectively, but with 95 per cent of locations received from less than 5489 m. Geese travelled along a route that was 112 km longer than the great circle (shortest distance) route, with transit ground speeds suggesting that they rarely profited from tailwinds. Bar-headed geese from these eastern populations generally travel only as high as the terrain beneath them dictates and rarely in profitable winds. Nevertheless, their migration represents an enormous challenge in conditions where humans and other mammals are only able to operate at levels well below their sea-level maxima. PMID:23118436

  14. The paradox of extreme high-altitude migration in bar-headed geese Anser indicus.

    PubMed

    Hawkes, L A; Balachandran, S; Batbayar, N; Butler, P J; Chua, B; Douglas, D C; Frappell, P B; Hou, Y; Milsom, W K; Newman, S H; Prosser, D J; Sathiyaselvam, P; Scott, G R; Takekawa, J Y; Natsagdorj, T; Wikelski, M; Witt, M J; Yan, B; Bishop, C M

    2013-01-07

    Bar-headed geese are renowned for migratory flights at extremely high altitudes over the world's tallest mountains, the Himalayas, where partial pressure of oxygen is dramatically reduced while flight costs, in terms of rate of oxygen consumption, are greatly increased. Such a mismatch is paradoxical, and it is not clear why geese might fly higher than is absolutely necessary. In addition, direct empirical measurements of high-altitude flight are lacking. We test whether migrating bar-headed geese actually minimize flight altitude and make use of favourable winds to reduce flight costs. By tracking 91 geese, we show that these birds typically travel through the valleys of the Himalayas and not over the summits. We report maximum flight altitudes of 7290 m and 6540 m for southbound and northbound geese, respectively, but with 95 per cent of locations received from less than 5489 m. Geese travelled along a route that was 112 km longer than the great circle (shortest distance) route, with transit ground speeds suggesting that they rarely profited from tailwinds. Bar-headed geese from these eastern populations generally travel only as high as the terrain beneath them dictates and rarely in profitable winds. Nevertheless, their migration represents an enormous challenge in conditions where humans and other mammals are only able to operate at levels well below their sea-level maxima.

  15. The paradox of extreme high-altitude migration in bar-headed geese Anser indicus

    USGS Publications Warehouse

    Hawkes, L.A.; Balachandran, S.; Batbayar, N.; Butler, P.J.; Chua, B.; Douglas, D.C.; Frappell, P.B.; Hou, Y.; Milsom, W.K.; Newman, S.H.; Prosser, D.J.; Sathiyaselvam, P.; Scott, G.R.; Takekawam, J.Y.; Natsagdorj, T.; Wikelski, M.; Witt, M.J.; Yan, B.; Bishop, C.M.

    2012-01-01

    Bar-headed geese are renowned for migratory flights at extremely high altitudes over the world's tallest mountains, the Himalayas, where partial pressure of oxygen is dramatically reduced while flight costs, in terms of rate of oxygen consumption, are greatly increased. Such a mismatch is paradoxical, and it is not clear why geese might fly higher than is absolutely necessary. In addition, direct empirical measurements of high-altitude flight are lacking. We test whether migrating bar-headed geese actually minimize flight altitude and make use of favourable winds to reduce flight costs. By tracking 91 geese, we show that these birds typically travel through the valleys of the Himalayas and not over the summits. We report maximum flight altitudes of 7290 m and 6540 m for southbound and northbound geese, respectively, but with 95 per cent of locations received from less than 5489 m. Geese travelled along a route that was 112 km longer than the great circle (shortest distance) route, with transit ground speeds suggesting that they rarely profited from tailwinds. Bar-headed geese from these eastern populations generally travel only as high as the terrain beneath them dictates and rarely in profitable winds. Nevertheless, their migration represents an enormous challenge in conditions where humans and other mammals are only able to operate at levels well below their sea-level maxima.

  16. The impact of moderate-altitude staging on pulmonary arterial hemodynamics after ascent to high altitude.

    PubMed

    Baggish, Aaron L; Fulco, Charles S; Muza, Stephen; Rock, Paul B; Beidleman, Beth; Cymerman, Allen; Yared, Kibar; Fagenholz, Peter; Systrom, David; Wood, Malissa J; Weyman, Arthur E; Picard, Michael H; Harris, N Stuart

    2010-01-01

    Staged ascent (SA), temporary residence at moderate altitude en route to high altitude, reduces the incidence and severity of noncardiopulmonary altitude illness such as acute mountain sickness. To date, the impact of SA on pulmonary arterial pressure (PAP) is unknown. We tested the hypothesis that SA would attenuate the PAP increase that occurs during rapid, direct ascent (DA). Transthoracic echocardiography was used to estimate mean PAP in 10 healthy males at sea level (SL, P(B) approximately 760 torr), after DA to simulated high altitude (hypobaric chamber, P(B) approximately 460 torr), and at 2 times points (90 min and 4 days) during exposure to terrestrial high altitude (P(B) approximately 460 torr) after SA (7 days, moderate altitude, P(B) approximately 548 torr). Alveolar oxygen pressure (Pao(2)) and arterial oxygenation saturation (Sao(2)) were measured at each time point. Compared to mean PAP at SL (mean +/- SD, 14 +/- 3 mmHg), mean PAP increased after DA to 37 +/- 8 mmHg (Delta = 24 +/- 10 mmHg, p < 0.001) and was negatively correlated with both Pao(2) (r(2) = 0.57, p = 0.011) and Sao(2) (r(2) = 0.64, p = 0.005). In comparison, estimated mean PAP after SA increased to only 25 +/- 4 mmHg (Delta = 11 +/- 6 mmHg, p < 0.001), remained unchanged after 4 days of high altitude residence (24 +/- 5 mmHg, p = not significant, or NS), and did not correlate with either parameter of oxygenation. SA significantly attenuated the PAP increase associated with continuous direct ascent to high altitude and appeared to uncouple PAP from both alveolar hypoxia and arterial hypoxemia.

  17. A Study of High Altitude Hypersonic Flow-Field Radiation

    NASA Technical Reports Server (NTRS)

    Moreau, Stephane; Park, Chul; Edwards, Thomas A. (Technical Monitor)

    1994-01-01

    This paper presents the results of the works carried out jointly at Stanford University and Ames Research Center under a grant from the Ballistic Missile Defense Organization (BMDO) (formerly the Strategic Defense Initiative Organization) to explain and understand the results of the two flight experiments, Bow Shock Ultra-Violet 1 and Bow Shock Ultra-Violet 2, carried out by the Organization. A portion of the material contained in this paper has been reported elsewhere in open literature. However, this paper provides (1) the details of scientific contents not available in those literature, (2) the links among those and the logical order of the efforts involved, and (3) some materials not contained in any open literature. The first author is responsible for execution of the work; the second author directed the work of the first author. In the two flight experiments mentioned above, the spectra of radiation in the ultraviolet wavelength range incident on the stagnation point of a blunt body were measured at the flight speeds of 3.8 and 5.2 km/sec over a wide range of altitudes. The results were compared first with the calculations made using the original version of the NEQAIR/STRAP codes written earlier by the second author. At low altitudes, the calculations agreed with the measurement. However, at high altitudes, the calculations underestimated the intensity of the radiation by several orders of magnitudes. A shock tube experiment was carried out at CALSPAN and a plasma-torch experiment was carried out at Stanford University to produce experimental data to help explain the discrepancy. In addition, the shock tube experiment at Ames Research Center carried out independently of the BMDO was also found to be relevant to this question. In this paper, several theoretical models are developed and calculations using the models were carried out to explain the results not only of the flight experiments but also of the CALSPAN, Stanford, and Ames experiments. The are: (1

  18. Why Are High-Altitude Natives So Strong at Altitude? Maximal Oxygen Transport to the Muscle Cell in Altitude Natives.

    PubMed

    Lundby, Carsten; Calbet, Jose A L

    2016-01-01

    In hypoxia aerobic exercise performance of high-altitude natives is suggested to be superior to that of lowlanders; i.e., for a given altitude natives are reported to have higher maximal oxygen uptake (VO2max). The likely basis for this is a higher pulmonary diffusion capacity, which in turn ensures higher arterial O2 saturation (SaO2) and therefore also potentially a higher delivery of O2 to the exercising muscles. This review focuses on O2 transport in high-altitude Aymara. We have quantified femoral artery O2 delivery, arterial O2 extraction and calculated leg VO2 in Aymara, and compared their values with that of acclimatizing Danish lowlanders. All subjects were studied at 4100 m. At maximal exercise SaO2 dropped tremendously in the lowlanders, but did not change in the Aymara. Therefore arterial O2 content was also higher in the Aymara. At maximal exercise however, fractional O2 extraction was lower in the Aymara, and the a-vO2 difference was similar in both populations. The lower extraction levels in the Aymara were associated with lower muscle O2 conductance (a measure of muscle diffusion capacity). At any given submaximal exercise intensity, leg VO2 was always of similar magnitude in both groups, but at maximal exercise the lowlanders had higher leg blood flow, and hence also higher maximum leg VO2. With the induction of acute normoxia fractional arterial O2 extraction fell in the highlanders, but remained unchanged in the lowlanders. Hence high-altitude natives seem to be more diffusion limited at the muscle level as compared to lowlanders. In conclusion Aymara preserve very high SaO2 during hypoxic exercise (likely due to a higher lung diffusion capacity), but the effect on VO2max is reduced by a lower ability to extract O2 at the muscle level.

  19. Long-term variation of OH peak emission altitude and volume emission rate over Indian low latitudes

    NASA Astrophysics Data System (ADS)

    Sivakandan, M.; Ramkumar, T. K.; Taori, A.; Rao, Venkateshwara; Niranjan, K.

    2016-02-01

    Using 13 (April 2002-December 2014) years of Sounding of the Atmosphere using Broadband Emission Radiometry (SABER/TIMED) 1.6 μm OH airglow emission data, we have studied the long-term variation of OH peak emission altitude and volume emission rate (VER) for 0-10°N latitude and 70-90°E longitude grid. We have noted that, during day time the OH peak emission altitude is varying from 80 to 87 km with mean value of 83.5 km and from 82 to 88 km with mean value of 85 km during night time. The signature of semi-annual oscillation (SAO), annual oscillation (AO) and quasi-biennial oscillation (QBO) in the OH peak emission altitude as well as the VER is evident. Our analysis reveals that the SAO and QBO signatures but not the AO signature are very strong in the equatorial region during night time. Apart from the SAO, AO and QBO signatures, the presence of oscillation related to the El Niño oscillation (ENSO) is also noted. After the removal of these oscillations, we find the evidence of the influence of solar activity and a long term trend in the OH emission layer. It is also found good correlation between the mesospheric and stratospheric variations (ECMWF data).

  20. Long-term variation of OH peak emission altitude and volume emission rate over Indian low latitudes

    NASA Astrophysics Data System (ADS)

    Sivakandan, Mani; Thokuluwa, Ramkumar; Kandula, Niranjan; Taori, Alok

    2016-07-01

    Using 13 (April 2002 -December 2014) years of Sounding of the Atmosphere using Broadband Emission Radiometry (SABER/TIMED) 1.6µm OH airglow emission data, we have studied the long-term variation of OH peak emission altitude and volume emission rate (VER) for 0-10 N latitude and 70-90 E longitude grid. We have noted that, during day time the OH peak emission altitude is varying from 80 to 87 km with mean value of 83.5 km and from 82 to 88 km with mean value of 85 km during night time. The signature of semi-annual oscillation (SAO), annual oscillation (AO) and quasi-biennial oscillation (QBO) in the OH peak emission altitude as well as the VER is evident. Our analysis reveals that the SAO and QBO signatures but not the AO signature are very strong in the equatorial region during night time. Apart from the SAO, AO and QBO signatures, the presence of oscillation related to the El Niño oscillation (ENSO) is also noted. After the removal of these oscillations, we find the evidence of the influence of solar activity and a long term trend in the OH emission layer. It is also found good correlation between the mesospheric and stratospheric variations (ECMWF data).

  1. A hypersonic shock tunnel test of the Aeroassist Flight Experiment (AFE) vehicle at high altitude test conditions

    NASA Technical Reports Server (NTRS)

    Wittliff, C. E.; O'Connor, A. C.; Sweet, S. J.

    1992-01-01

    The Aeroassist Flight Experiment (AFE) vehicle is a 4.26 m-diameter raked and blunted elliptic cone that is intended to obtain aerodynamic and aerothermodynamic data on blunt bodies at velocities near 10 km/s and altitudes above 75 km. Previous wind tunnel tests of this configuration have been at Mach numbers of 10 or lower. The present test program consisted of five test conditions at Mach numbers between 15 and 20 and simulated altitudes from 75 km to 97 km. Static longitudinal aerodynamic coefficients, the lift-to-drag ratio, and the trim angle-of-attack were obtained for angles-of-attack between 7 deg and 27 deg. The effects of angle-of-attack and shock Reynolds number, Re2, have been studied. These results indicate the AFE configuration is longitudinally stable. The variation of normal force slope, CNalpha and lift-to-drag slope, (L/D)alpha as well as the trim angle-of-attack with Re2 are documented. The trim angle-of-attack increases with decreasing values of shock Reynolds number (increasing altitude) while the lift-to-drag ratio at the trimmed conditions is relatively constant.

  2. 7 CFR 29.1035 - Mixed color (KM).

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 2 2014-01-01 2014-01-01 false Mixed color (KM). 29.1035 Section 29.1035 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... Type 92) § 29.1035 Mixed color (KM). Distinctly different colors of the type mingled together....

  3. 7 CFR 29.1035 - Mixed color (KM).

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 2 2013-01-01 2013-01-01 false Mixed color (KM). 29.1035 Section 29.1035 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... Type 92) § 29.1035 Mixed color (KM). Distinctly different colors of the type mingled together....

  4. 7 CFR 29.1035 - Mixed color (KM).

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 2 2012-01-01 2012-01-01 false Mixed color (KM). 29.1035 Section 29.1035 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... Type 92) § 29.1035 Mixed color (KM). Distinctly different colors of the type mingled together....

  5. 7 CFR 29.1035 - Mixed color (KM).

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Mixed color (KM). 29.1035 Section 29.1035 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... Type 92) § 29.1035 Mixed color (KM). Distinctly different colors of the type mingled together....

  6. 7 CFR 29.1035 - Mixed color (KM).

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 2 2011-01-01 2011-01-01 false Mixed color (KM). 29.1035 Section 29.1035 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... Type 92) § 29.1035 Mixed color (KM). Distinctly different colors of the type mingled together....

  7. Acute high-altitude illness: a clinically orientated review

    PubMed Central

    Smedley, Tom

    2013-01-01

    Acute high-altitude illness is an encompassing term for the range of pathology that the unacclimatised individual can develop at increased altitude. This includes acute mountain sickness, high-altitude cerebral oedema and high-altitude pulmonary oedema. These conditions represent an increasing clinical problem as more individuals are exposed to the hypobaric hypoxic environment of high altitude for both work and leisure. In this review of acute high-altitude illness, the epidemiology, risk factors and pathophysiology are explored, before their prevention and treatment are discussed. Appropriate ascent rate remains the most effective acute high-altitude illness prevention, with pharmacological prophylaxis indicated in selected individuals. Descent is the definitive treatment for acute high-altitude illness, with the adjuncts of oxygen and specific drug therapies. PMID:26516505

  8. Design and Development of a High Altitude Protective Assembly.

    DTIC Science & Technology

    CWU-3/P ANTIGRAVITY SUITS, CWU-12/P ANTIEXPOSURE SUITS, HAPA(HIGH ALTITUDE PROTECTIVE ASSEMBLIES), *HIGH ALTITUDE PROTECTIVE ASSEMBLIES, LPU-3/P LIFE PRESERVERS, MA-3 VENTILATION GARMENTS, PARACHUTE HARNESSES, PARTIAL PRESSURE SUITS.

  9. DETAIL OF VACUUM PIPE OPENING WITHIN ALTITUDE CHAMBER R, FACING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    DETAIL OF VACUUM PIPE OPENING WITHIN ALTITUDE CHAMBER R, FACING SOUTHEAST - Cape Canaveral Air Force Station, Launch Complex 39, Altitude Chambers, First Street, between Avenue D and Avenue E, Cape Canaveral, Brevard County, FL

  10. INTERIOR OF ALTITUDE CHAMBER L FROM TOP LEVEL OF ACCESS ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    INTERIOR OF ALTITUDE CHAMBER L FROM TOP LEVEL OF ACCESS PLATFORMS, FACING WEST - Cape Canaveral Air Force Station, Launch Complex 39, Altitude Chambers, First Street, between Avenue D and Avenue E, Cape Canaveral, Brevard County, FL

  11. EXTERIOR VIEW OF AIRLOCK FOR ALTITUDE CHAMBER R, FACING SOUTHEAST ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    EXTERIOR VIEW OF AIRLOCK FOR ALTITUDE CHAMBER R, FACING SOUTHEAST - Cape Canaveral Air Force Station, Launch Complex 39, Altitude Chambers, First Street, between Avenue D and Avenue E, Cape Canaveral, Brevard County, FL

  12. UPPER HALF OF THE INTERIOR OF ALTITUDE CHAMBER R, LOOKING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    UPPER HALF OF THE INTERIOR OF ALTITUDE CHAMBER R, LOOKING UP FROM BOTTOM LEVEL, FACING NORTHEAST - Cape Canaveral Air Force Station, Launch Complex 39, Altitude Chambers, First Street, between Avenue D and Avenue E, Cape Canaveral, Brevard County, FL

  13. INTERIOR OF ALTITUDE CHAMBER L, LOOKING UP FROM BOTTOM LEVEL ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    INTERIOR OF ALTITUDE CHAMBER L, LOOKING UP FROM BOTTOM LEVEL OF INTERNAL PLATFORMS, FACING EAST - Cape Canaveral Air Force Station, Launch Complex 39, Altitude Chambers, First Street, between Avenue D and Avenue E, Cape Canaveral, Brevard County, FL

  14. EXTERIOR OF ALTITUDE CHAMBERS R (TO LEFT) AND L (TO ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    EXTERIOR OF ALTITUDE CHAMBERS R (TO LEFT) AND L (TO RIGHT), FACING NORTHEAST - Cape Canaveral Air Force Station, Launch Complex 39, Altitude Chambers, First Street, between Avenue D and Avenue E, Cape Canaveral, Brevard County, FL

  15. VIEW OF THE CONTROL ROOM FOR THE ALTITUDE CHAMBERS, FACING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW OF THE CONTROL ROOM FOR THE ALTITUDE CHAMBERS, FACING SOUTHWEST - Cape Canaveral Air Force Station, Launch Complex 39, Altitude Chambers, First Street, between Avenue D and Avenue E, Cape Canaveral, Brevard County, FL

  16. BOTTOM LEVEL OF ALTITUDE CHAMBER L, FACING SOUTHWEST Cape ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    BOTTOM LEVEL OF ALTITUDE CHAMBER L, FACING SOUTHWEST - Cape Canaveral Air Force Station, Launch Complex 39, Altitude Chambers, First Street, between Avenue D and Avenue E, Cape Canaveral, Brevard County, FL

  17. DETAIL OF DOMED BOTTOM, ALTITUDE CHAMBER R, FACING EAST ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    DETAIL OF DOMED BOTTOM, ALTITUDE CHAMBER R, FACING EAST - Cape Canaveral Air Force Station, Launch Complex 39, Altitude Chambers, First Street, between Avenue D and Avenue E, Cape Canaveral, Brevard County, FL

  18. VIEW OF PUMP ROOM FOR ALTITUDE CHAMBERS, FACING SOUTHWEST ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW OF PUMP ROOM FOR ALTITUDE CHAMBERS, FACING SOUTHWEST - Cape Canaveral Air Force Station, Launch Complex 39, Altitude Chambers, First Street, between Avenue D and Avenue E, Cape Canaveral, Brevard County, FL

  19. EXTERIOR AND INTERIOR VIEW OF AIRLOCK FOR ALTITUDE CHAMBER R, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    EXTERIOR AND INTERIOR VIEW OF AIRLOCK FOR ALTITUDE CHAMBER R, FACING SOUTH - Cape Canaveral Air Force Station, Launch Complex 39, Altitude Chambers, First Street, between Avenue D and Avenue E, Cape Canaveral, Brevard County, FL

  20. DETAIL OF REPRESSURIZATION AIR PIPE, ALTITUDE CHAMBER L, FACING SOUTHWEST ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    DETAIL OF RE-PRESSURIZATION AIR PIPE, ALTITUDE CHAMBER L, FACING SOUTHWEST - Cape Canaveral Air Force Station, Launch Complex 39, Altitude Chambers, First Street, between Avenue D and Avenue E, Cape Canaveral, Brevard County, FL

  1. DETAIL OF DOMED BOTTOM, ALTITUDE CHAMBER L, FACING NORTHWEST ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    DETAIL OF DOMED BOTTOM, ALTITUDE CHAMBER L, FACING NORTHWEST - Cape Canaveral Air Force Station, Launch Complex 39, Altitude Chambers, First Street, between Avenue D and Avenue E, Cape Canaveral, Brevard County, FL

  2. DETAIL OF WALLMOUNTED STAIRS ON INTERIOR OF ALTITUDE CHAMBER L, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    DETAIL OF WALL-MOUNTED STAIRS ON INTERIOR OF ALTITUDE CHAMBER L, FACING SOUTHWEST - Cape Canaveral Air Force Station, Launch Complex 39, Altitude Chambers, First Street, between Avenue D and Avenue E, Cape Canaveral, Brevard County, FL

  3. INTERIOR OF AIRLOCK FROM INTERIOR OF ALTITUDE CHAMBER R, FACING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    INTERIOR OF AIRLOCK FROM INTERIOR OF ALTITUDE CHAMBER R, FACING NORTHWEST - Cape Canaveral Air Force Station, Launch Complex 39, Altitude Chambers, First Street, between Avenue D and Avenue E, Cape Canaveral, Brevard County, FL

  4. LOWER HALF OF THE INTERIOR OF ALTITUDE CHAMBER R, LOOKING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    LOWER HALF OF THE INTERIOR OF ALTITUDE CHAMBER R, LOOKING UP FROM BOTTOM LEVEL, FACING NORTHEAST - Cape Canaveral Air Force Station, Launch Complex 39, Altitude Chambers, First Street, between Avenue D and Avenue E, Cape Canaveral, Brevard County, FL

  5. DETAIL OF PLATFORM SUPPORT BRACKET, ALTITUDE CHAMBER L, FACING NORTHWEST ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    DETAIL OF PLATFORM SUPPORT BRACKET, ALTITUDE CHAMBER L, FACING NORTHWEST - Cape Canaveral Air Force Station, Launch Complex 39, Altitude Chambers, First Street, between Avenue D and Avenue E, Cape Canaveral, Brevard County, FL

  6. INTERIOR OF ALTITUDE CHAMBER R, LOOKING DOWN FROM AIRLOCK, FACING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    INTERIOR OF ALTITUDE CHAMBER R, LOOKING DOWN FROM AIRLOCK, FACING NORTHWEST - Cape Canaveral Air Force Station, Launch Complex 39, Altitude Chambers, First Street, between Avenue D and Avenue E, Cape Canaveral, Brevard County, FL

  7. EXTERIOR OF ALTITUDE CHAMBERS R (TO LEFT) AND L (TO ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    EXTERIOR OF ALTITUDE CHAMBERS R (TO LEFT) AND L (TO RIGHT), FACING NORTHWEST - Cape Canaveral Air Force Station, Launch Complex 39, Altitude Chambers, First Street, between Avenue D and Avenue E, Cape Canaveral, Brevard County, FL

  8. DETAIL OF THE EXTERIOR OF THE DOMED LID, ALTITUDE CHAMBER ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    DETAIL OF THE EXTERIOR OF THE DOMED LID, ALTITUDE CHAMBER R, FACING NORTHWEST - Cape Canaveral Air Force Station, Launch Complex 39, Altitude Chambers, First Street, between Avenue D and Avenue E, Cape Canaveral, Brevard County, FL

  9. DETAIL OF THE INTERIOR OF THE DOMED LID, ALTITUDE CHAMBER ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    DETAIL OF THE INTERIOR OF THE DOMED LID, ALTITUDE CHAMBER R, FACING NORTHWEST - Cape Canaveral Air Force Station, Launch Complex 39, Altitude Chambers, First Street, between Avenue D and Avenue E, Cape Canaveral, Brevard County, FL

  10. Wave-like perturbations observed at low altitudes by the Pioneer Venus Orbiter Neutral Mass Spectrometer during orbiter entry

    NASA Technical Reports Server (NTRS)

    Kasprzak, W. T.; Niemann, H. B.; Hedin, A. E.; Bougher, S. W.

    1993-01-01

    Wave-like perturbations have been observed in the nightside neutral density data acquired for He, N, O, N2 and CO2 by the Pioneer Venus Orbiter Neutral Mass Spectrometer (ONMS) during entry in late 1992. The data cover an altitude range of 133-200 km from 0.5-4.5 hours local solar time and occur at medium solar activity (F(sub 10.7) = 120). The perturbations, with an effective wavelength along the orbit of about 100 to 600 km, have similar amplitudes for the various species and helium is out of phase with respect to the heavier mass species. The measurements are comparable to those observed in 1978-80 at solar maximum activity (F(sub 10.7) = 200) above 145 km. Between 133 and 160 km the rms amplitudes grow with altitude at a rate of about (1.6, 2.1, 2.7, 4.4) x 10(exp 3)/km for N, O, N2, and CO2, respectively. The average rms amplitudes above 145 km of 0.08 for N and O and 0.1 for N2 are comparable in magnitude to those observed in the earlier 1978-80 data of 0.06, 0.08, and 0.095 respectively. CO2 is an exception for which the entry value is 0.17 compared to 0.09 earlier. By combining the two overlapping data sets there is a suggestion that the CO2 amplitudes grow in value with altitude up to about 140-170 km and then decrease in amplitude. Like the earlier data, the entry data are consistent with the interpretation that the neutral density perturbations are due to gravity waves propagating upward from the lower thermosphere.

  11. High Altitude Balloons as a Platform for Space Radiation Belt Science

    NASA Astrophysics Data System (ADS)

    Mazzino, L.; Buttenschoen, A.; Farr, Q.; Hodgson, C.; Johnson, W.; Mann, I. R.; Rae, J.; University of Alberta High Altitude Balloons (UA-HAB)

    2011-12-01

    The goals of the University of Alberta High Altitude Balloons Program (UA-HAB) are to i) use low cost balloons to address space radiation science, and ii) to utilise the excitement of "space mission" involvement to promote and facilitate the recruitment of undergraduate and graduate students in physics, engineering, and atmospheric sciences to pursue careers in space science and engineering. The University of Alberta High Altitude Balloons (UA-HAB) is a unique opportunity for University of Alberta students (undergraduate and graduate) to engage in the hands-on design, development, build, test and flight of a payload to operate on a high altitude balloon at around 30km altitude. The program development, including formal design and acceptance tests, reports and reviews, mirror those required in the development of an orbital satellite mission. This enables the students to gain a unique insight into how space missions are flown. UA-HAB is a one and half year program that offers a gateway into a high-altitude balloon mission through hands on experience, and builds skills for students who may be attracted to participate in future space missions in their careers. This early education will provide students with the experience necessary to better assess opportunities for pursuing a career in space science. Balloons offer a low-cost alternative to other suborbital platforms which can be used to address radiation belt science goals. In particular, the participants of this program have written grant proposal to secure funds for this project, have launched several 'weather balloon missions', and have designed, built, tested, and launched their particle detector called "Maple Leaf Particle Detector". This detector was focussed on monitoring cosmic rays and space radiation using shielded Geiger tubes, and was flown as one of the payloads from the institutions participating in the High Altitude Student Platform (HASP), organized by the Louisiana State University and the Louisiana

  12. Exploring KM Features of High-Performance Companies

    NASA Astrophysics Data System (ADS)

    Wu, Wei-Wen

    2007-12-01

    For reacting to an increasingly rival business environment, many companies emphasize the importance of knowledge management (KM). It is a favorable way to explore and learn KM features of high-performance companies. However, finding out the critical KM features of high-performance companies is a qualitative analysis problem. To handle this kind of problem, the rough set approach is suitable because it is based on data-mining techniques to discover knowledge without rigorous statistical assumptions. Thus, this paper explored KM features of high-performance companies by using the rough set approach. The results show that high-performance companies stress the importance on both tacit and explicit knowledge, and consider that incentives and evaluations are the essentials to implementing KM.

  13. Field-aligned electron density irregularities near 500 km Equator to polar cap topside sounder observations

    NASA Astrophysics Data System (ADS)

    Benson, R. F.

    1985-06-01

    In addition to spread F, evidence for field-aligned electron density irregularities is commonly observed on Alouette 2 topside sounder ionograms recorded near perigee (500 km). This evidence is provided by distinctive signal returns from sounder-generated Z mode waves. At low latitudes these waves become guided in wave ducts caused by field-aligned electron density irregularities and give rise to strong long-duration echoes. At high latitudes, extending well into the polar cap, these Z mode waves (and stimulated electrostatic waves at the plasma frequency) produce a series of vertical bars on the ionogram display as the satellite traverses discrete field-aligned density structures. The radio frequency (RF) noise environment to be expected in the 400 to 500 km altitude region from low to high latitudes was examined by analyzing perigee Alouette 2 topside sounder data. All observed noise bands were scaled on nearly 200 topside sounder ionograms recorded near perigee at low, mid, and high latitude telemetry stations. The minimum and maximum frequencies of each noise band were entered into a data base or computer analysis. The signals of primary interest in the perigee study were found to be sounder-generated.

  14. Field-aligned electron density irregularities near 500 km Equator to polar cap topside sounder observations

    NASA Technical Reports Server (NTRS)

    Benson, R. F.

    1985-01-01

    In addition to spread F, evidence for field-aligned electron density irregularities is commonly observed on Alouette 2 topside sounder ionograms recorded near perigee (500 km). This evidence is provided by distinctive signal returns from sounder-generated Z mode waves. At low latitudes these waves become guided in wave ducts caused by field-aligned electron density irregularities and give rise to strong long-duration echoes. At high latitudes, extending well into the polar cap, these Z mode waves (and stimulated electrostatic waves at the plasma frequency) produce a series of vertical bars on the ionogram display as the satellite traverses discrete field-aligned density structures. The radio frequency (RF) noise environment to be expected in the 400 to 500 km altitude region from low to high latitudes was examined by analyzing perigee Alouette 2 topside sounder data. All observed noise bands were scaled on nearly 200 topside sounder ionograms recorded near perigee at low, mid, and high latitude telemetry stations. The minimum and maximum frequencies of each noise band were entered into a data base or computer analysis. The signals of primary interest in the perigee study were found to be sounder-generated.

  15. Field-aligned electron density irregularities near 500 km Equator to polar cap topside sounder observations

    SciTech Connect

    Benson, R.F.

    1985-06-01

    In addition to spread F, evidence for field-aligned electron density irregularities is commonly observed on Alouette 2 topside sounder ionograms recorded near perigee (500 km). This evidence is provided by distinctive signal returns from sounder-generated Z mode waves. At low latitudes these waves become guided in wave ducts caused by field-aligned electron density irregularities and give rise to strong long-duration echoes. At high latitudes, extending well into the polar cap, these Z mode waves (and stimulated electrostatic waves at the plasma frequency) produce a series of vertical bars on the ionogram display as the satellite traverses discrete field-aligned density structures. The radio frequency (RF) noise environment to be expected in the 400 to 500 km altitude region from low to high latitudes was examined by analyzing perigee Alouette 2 topside sounder data. All observed noise bands were scaled on nearly 200 topside sounder ionograms recorded near perigee at low, mid, and high latitude telemetry stations. The minimum and maximum frequencies of each noise band were entered into a data base or computer analysis. The signals of primary interest in the perigee study were found to be sounder-generated. 15 references.

  16. Prototype of readout electronics for the LHAASO KM2A electromagnetic particle detectors

    NASA Astrophysics Data System (ADS)

    Liu, Xiang; Chang, Jing-Fan; Wang, Zheng; Fan, Lei

    2016-07-01

    The KM2A (one kilometer square extensive air shower array) is the largest detector array in the LHAASO (Large High Altitude Air Shower Observatory) project. The KM2A consists of 5242 EDs (Electromagnetic particle Detectors) and 1221 MDs (Muon Detectors). The EDs are distributed and exposed in the wild. Two channels, anode and dynode, are employed for the PMT (photomultiplier tube) signal readout. The readout electronics designed in this paper aims at accurate charge and arrival time measurement of the PMT signals, which cover a large amplitude range from 20 P.E. (photoelectrons) to 2 × 105 P.E. By using a “trigger-less” architecture, we digitize signals close to the PMTs. All digitized data is transmitted to DAQ (Data Acquisition) via a simplified White Rabbit protocol. Compared with traditional high energy experiments, high precision of time measurement over such a large area and suppression of temperature effects in the wild become the key techniques. Experiments show that the design has fulfilled the requirements in this project. Supported by National Natural Science Foundation of China (11375210) and the Knowledge Innovation Fund of IHEP, Beijing

  17. The High Altitude Gamma Ray Observatory, HAWC

    NASA Astrophysics Data System (ADS)

    González, M. M.

    2011-10-01

    The Volcano Sierra Negra in Puebla, Mexico was selected to host HAWC (High Altitude Water Cherenkov), a unique obervatory of wide field of view (2π sr) capable of observing the sky continously at energies from 0.5 TeV to 100 TeV. HAWC is an array of 300 large water tanks (7.3 m diameter × 5 m depth) at an altitude of 4100 m. a. s. l. Each tank is instrumented with three upward-looking photomultipliers tubes. The full array will be capable of observing the most energetic gamma rays from the most violent events in the universe. HAWC will be 15 times more sensitive than its predecesor, Milagro. We present HAWC, the scientific case and capabilities.

  18. [Effect of altitude on iron absorption].

    PubMed

    Pizarro, F; Zavaleta, N; Hertrampf, E; Berlanga, R; Camborda, L; Olivares, M

    1998-03-01

    Iron bioavailability was evaluated in people living in high altitudes. Absorption was estimated from a reference dose of ferrous ascorbate and from a standard diet of wheat flour, using extrinsic tag radioisotope technique of 55Fe and 59Fe. Twenty four volunteers, healthy women, with ages ranging from 28 to 45 years, participated. Of those, eleven lived at 3450 meters above sea level (m.a.s.l.) in Huancayo city-Peru (study group), and 13 lived in Santiago de Chile at 630 m.a.s.l. (control group). Iron absorption from reference dose of ferrous ascorbate was 32.0% and 31.1% in the study and control groups respectively. The geometric mean of iron absorption from the standard diet, corrected to 40% of absorption of reference dose, was 9.0% and 6.9% in the study and control groups respectively (NS). The results suggest that altitude does not produce a high iron absorption in highlander residents.

  19. Dust observations at orbital altitudes surrounding Mars.

    PubMed

    Andersson, L; Weber, T D; Malaspina, D; Crary, F; Ergun, R E; Delory, G T; Fowler, C M; Morooka, M W; McEnulty, T; Eriksson, A I; Andrews, D J; Horanyi, M; Collette, A; Yelle, R; Jakosky, B M

    2015-11-06

    Dust is common close to the martian surface, but no known process can lift appreciable concentrations of particles to altitudes above ~150 kilometers. We present observations of dust at altitudes ranging from 150 to above 1000 kilometers by the Langmuir Probe and Wave instrument on the Mars Atmosphere and Volatile Evolution spacecraft. Based on its distribution, we interpret this dust to be interplanetary in origin. A comparison with laboratory measurements indicates that the dust grain size ranges from 1 to 12 micrometers, assuming a typical grain velocity of ~18 kilometers per second. These direct observations of dust entering the martian atmosphere improve our understanding of the sources, sinks, and transport of interplanetary dust throughout the inner solar system and the associated impacts on Mars's atmosphere.

  20. HAWC - The High Altitude Water Cherenkov Detector

    NASA Astrophysics Data System (ADS)

    Tepe, Andreas; HAWC Collaboration

    2012-07-01

    The high altitude water Cherenkov observatory (HAWC) is an instrument for the detection of high energy cosmic gamma-rays. Its predecessor Milagro has successfully proven that the water Cherenkov technology for gamma-ray astronomy is a useful technique. HAWC is currently under construction at Sierra Negra in Mexico at an altitude of 4100 m and will include several improvements compared to Milagro. Two complementary DAQ systems of the HAWC detector allow for the observation of a large fraction of the sky with a very high duty cycle and independent of environmental conditions. HAWC will observe the gamma-ray sky from about 100 GeV up to 100 TeV. Also the cosmic ray flux anisotropy on different angular length scales is object of HAWC science. Because of HAWC's large effective area and field of view, we describe its prospects to observe gamma-ray bursts (GRBs) as an example for transient sources.

  1. Development of a high altitude Spin Parachute

    NASA Technical Reports Server (NTRS)

    Silbert, M. N.

    1981-01-01

    A specially configured 16.6 foot (5.1 meter) Disc Gap Band (DGB) Spin Parachute has been designed, developed, integrated with a sounding rocket, and qualified by flight testing. Design requirements include (1) stable parachute should successfully deploy in the altitude region of 260,000 feet (80 kilometers) from a Super Arcas launch vehicle; (2) after deployment, parachute and payload spin rate should be greater than three rpm; (3) four electric field sensors should be mounted on parachute shroud lines and have provisions to be electrically connected to the suspended payload; and (4) time above 100,000 feet (30 kilometers) should exceed five minutes. The successful meeting of these requirements provided the first known high-altitude deployment of a Spin Parachute.

  2. Marshall Space Flight Center Propulsion Systems Department (PSD) KM Initiative

    NASA Technical Reports Server (NTRS)

    Caraccioli, Paul; Varnadoe, Tom; McCarter, Mike

    2006-01-01

    NASA Marshall Space Flight Center s Propulsion Systems Department (PSD) is four months into a fifteen month Knowledge Management (KM) initiative to support enhanced engineering decision making and analyses, faster resolution of anomalies (near-term) and effective, efficient knowledge infused engineering processes, reduced knowledge attrition, and reduced anomaly occurrences (long-term). The near-term objective of this initiative is developing a KM Pilot project, within the context of a 3-5 year KM strategy, to introduce and evaluate the use of KM within PSD. An internal NASA/MSFC PSD KM team was established early in project formulation to maintain a practitioner, user-centric focus throughout the conceptual development, planning and deployment of KM technologies and capabilities with in the PSD. The PSD internal team is supported by the University of Alabama's Aging Infrastructure Systems Center Of Excellence (AISCE), Intergraph Corporation, and The Knowledge Institute. The principle product of the initial four month effort has been strategic planning of PSD KM implementation by first determining the "as is" state of KM capabilities and developing, planning and documenting the roadmap to achieve the desired "to be" state. Activities undertaken to support the planning phase have included data gathering; cultural surveys, group work-sessions, interviews, documentation review, and independent research. Assessments and analyses have been performed including industry benchmarking, related local and Agency initiatives, specific tools and techniques used and strategies for leveraging existing resources, people and technology to achieve common KM goals. Key findings captured in the PSD KM Strategic Plan include the system vision, purpose, stakeholders, prioritized strategic objectives mapped to the top ten practitioner needs and analysis of current resource usage. Opportunities identified from research, analyses, cultural/KM surveys and practitioner interviews include

  3. 14 CFR 121.661 - Initial approach altitude: Flag operations.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 3 2013-01-01 2013-01-01 false Initial approach altitude: Flag operations... § 121.661 Initial approach altitude: Flag operations. When making an initial approach to a radio navigation facility under IFR, no person may descend below the pertinent minimum altitude for...

  4. 10 CFR 862.6 - Voluntary minimum altitude.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 4 2013-01-01 2013-01-01 false Voluntary minimum altitude. 862.6 Section 862.6 Energy... § 862.6 Voluntary minimum altitude. In addition to complying with all applicable FAA prohibitions or restrictions, aircraft are requested to maintain a minimum altitude of 2,000 feet above the terrain of...

  5. 14 CFR 29.1527 - Maximum operating altitude.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Maximum operating altitude. 29.1527 Section 29.1527 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT... Limitations § 29.1527 Maximum operating altitude. The maximum altitude up to which operation is allowed,...

  6. 14 CFR 121.661 - Initial approach altitude: Flag operations.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 3 2012-01-01 2012-01-01 false Initial approach altitude: Flag operations... § 121.661 Initial approach altitude: Flag operations. When making an initial approach to a radio navigation facility under IFR, no person may descend below the pertinent minimum altitude for...

  7. 10 CFR 862.6 - Voluntary minimum altitude.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 4 2012-01-01 2012-01-01 false Voluntary minimum altitude. 862.6 Section 862.6 Energy... § 862.6 Voluntary minimum altitude. In addition to complying with all applicable FAA prohibitions or restrictions, aircraft are requested to maintain a minimum altitude of 2,000 feet above the terrain of...

  8. 14 CFR 27.1527 - Maximum operating altitude.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Maximum operating altitude. 27.1527 Section 27.1527 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT... § 27.1527 Maximum operating altitude. The maximum altitude up to which operation is allowed, as...

  9. 14 CFR 121.661 - Initial approach altitude: Flag operations.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 3 2014-01-01 2014-01-01 false Initial approach altitude: Flag operations... § 121.661 Initial approach altitude: Flag operations. When making an initial approach to a radio navigation facility under IFR, no person may descend below the pertinent minimum altitude for...

  10. 14 CFR 27.1527 - Maximum operating altitude.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Maximum operating altitude. 27.1527 Section 27.1527 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT... § 27.1527 Maximum operating altitude. The maximum altitude up to which operation is allowed, as...

  11. VIEW OF THE TOPS OF ALTITUDE CHAMBER R (TO LEFT) ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW OF THE TOPS OF ALTITUDE CHAMBER R (TO LEFT) AND ALTITUDE CHAMBER L (TO RIGHT) FROM THE 42’-0” LEVEL OF ACCESS PLATFORMS, FACING NORTHWEST - Cape Canaveral Air Force Station, Launch Complex 39, Altitude Chambers, First Street, between Avenue D and Avenue E, Cape Canaveral, Brevard County, FL

  12. 14 CFR 121.661 - Initial approach altitude: Flag operations.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 3 2011-01-01 2011-01-01 false Initial approach altitude: Flag operations... § 121.661 Initial approach altitude: Flag operations. When making an initial approach to a radio navigation facility under IFR, no person may descend below the pertinent minimum altitude for...

  13. 14 CFR 91.515 - Flight altitude rules.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 2 2013-01-01 2013-01-01 false Flight altitude rules. 91.515 Section 91... Multiengine Airplanes and Fractional Ownership Program Aircraft § 91.515 Flight altitude rules. (a..., hill, or other obstruction to flight, for day operations; and (2) The altitudes prescribed in §...

  14. 14 CFR 91.515 - Flight altitude rules.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 2 2014-01-01 2014-01-01 false Flight altitude rules. 91.515 Section 91... Multiengine Airplanes and Fractional Ownership Program Aircraft § 91.515 Flight altitude rules. (a..., hill, or other obstruction to flight, for day operations; and (2) The altitudes prescribed in §...

  15. 14 CFR 91.515 - Flight altitude rules.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 2 2011-01-01 2011-01-01 false Flight altitude rules. 91.515 Section 91... Multiengine Airplanes and Fractional Ownership Program Aircraft § 91.515 Flight altitude rules. (a..., hill, or other obstruction to flight, for day operations; and (2) The altitudes prescribed in §...

  16. 14 CFR 27.1527 - Maximum operating altitude.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Maximum operating altitude. 27.1527 Section 27.1527 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT... § 27.1527 Maximum operating altitude. The maximum altitude up to which operation is allowed, as...

  17. 14 CFR 29.1527 - Maximum operating altitude.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Maximum operating altitude. 29.1527 Section 29.1527 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT... Limitations § 29.1527 Maximum operating altitude. The maximum altitude up to which operation is allowed,...

  18. 14 CFR 29.1527 - Maximum operating altitude.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Maximum operating altitude. 29.1527 Section 29.1527 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT... Limitations § 29.1527 Maximum operating altitude. The maximum altitude up to which operation is allowed,...

  19. 10 CFR 862.6 - Voluntary minimum altitude.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 4 2014-01-01 2014-01-01 false Voluntary minimum altitude. 862.6 Section 862.6 Energy... § 862.6 Voluntary minimum altitude. In addition to complying with all applicable FAA prohibitions or restrictions, aircraft are requested to maintain a minimum altitude of 2,000 feet above the terrain of...

  20. 10 CFR 862.6 - Voluntary minimum altitude.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 4 2011-01-01 2011-01-01 false Voluntary minimum altitude. 862.6 Section 862.6 Energy... § 862.6 Voluntary minimum altitude. In addition to complying with all applicable FAA prohibitions or restrictions, aircraft are requested to maintain a minimum altitude of 2,000 feet above the terrain of...

  1. 14 CFR 27.1527 - Maximum operating altitude.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Maximum operating altitude. 27.1527 Section 27.1527 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT... § 27.1527 Maximum operating altitude. The maximum altitude up to which operation is allowed, as...

  2. 14 CFR 29.1527 - Maximum operating altitude.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Maximum operating altitude. 29.1527 Section 29.1527 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT... Limitations § 29.1527 Maximum operating altitude. The maximum altitude up to which operation is allowed,...

  3. 14 CFR 91.515 - Flight altitude rules.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 2 2012-01-01 2012-01-01 false Flight altitude rules. 91.515 Section 91... Multiengine Airplanes and Fractional Ownership Program Aircraft § 91.515 Flight altitude rules. (a..., hill, or other obstruction to flight, for day operations; and (2) The altitudes prescribed in §...

  4. 14 CFR 27.1527 - Maximum operating altitude.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Maximum operating altitude. 27.1527 Section 27.1527 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT... § 27.1527 Maximum operating altitude. The maximum altitude up to which operation is allowed, as...

  5. 14 CFR 121.661 - Initial approach altitude: Flag operations.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Initial approach altitude: Flag operations... § 121.661 Initial approach altitude: Flag operations. When making an initial approach to a radio navigation facility under IFR, no person may descend below the pertinent minimum altitude for...

  6. 14 CFR 29.1527 - Maximum operating altitude.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Maximum operating altitude. 29.1527 Section 29.1527 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT... Limitations § 29.1527 Maximum operating altitude. The maximum altitude up to which operation is allowed,...

  7. Human Behaviour and Development under High-Altitude Conditions

    ERIC Educational Resources Information Center

    Virues-Ortega, Javier; Garrido, Eduardo; Javierre, Casimiro; Kloezeman, Karen C.

    2006-01-01

    Although we are far from a universally accepted pattern of impaired function at altitude, there is evidence indicating motor, perceptual, memory and behavioural deficits in adults. Even relatively low altitudes (2500 m) may delay reaction time, and impair motor function. Extreme altitude exposure (greater than 5000 m) may result in more pronounced…

  8. Gravity anomalies near the east Pacific rise with wavelengths shorter than 3300 km recovered from GEOS-3/ATS-6 satellite-to-satellite Doppler tracking data

    NASA Technical Reports Server (NTRS)

    Marsh, J. G.; Marsh, B. D.; Conrad, T. D.; Wells, W. T.; Williamson, R. G.

    1977-01-01

    The velocity of the GEOS-3 satellite measured by Doppler as a function of time from the ATS-6 satellite was used to recover gravity anomalies in the region of the East Pacific. The orbit GEOS-3 at an altitude of 840 km was perturbed by spatial changes in Earth's gravitational field. These perturbations were measured via ATS-6 which is in a synchronous orbit at an altitude of about 40,000 km. The range-rate data were reduced using a gravitational field model complete to the 12 degree and order. A simulation of the possible effects causing the remaining range-rate residuals relative to the 12, 12 field shows that in general the dominant effect is the neglect of the higher degree and order coefficients of the gravitational field model.

  9. Hazards of Altitude Testing at AEDC

    DTIC Science & Technology

    1992-08-01

    12 kbar. Initiation can also take place by XDT (Unknown-to- Detonation - Transition) under conditions less severe than for SDT. This might occur... XDT of approximately 3 kbar. DETONATION REQUIREMENTS AND DISTRIBUTION FUNCTION Ullianl reported the "TNT EquivalentI1 of a series of aborted flights...HAZARDS OF ALTITUDE TESTING AT AEDC Paul K. Salzman TRW San Bernardino, CA ABSTRACT The detonability (explosion) hazards associated with testing

  10. 75 FR 40720 - IFR Altitudes; Miscellaneous Amendments

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-14

    ... From To MEA MAA Sec. 95.3000 LOW ALTITUDE RNAV ROUTES Sec. 95.3227 RNAV ROUTE T227 IS AMENDED TO READ... 17500 *1300--MOCA From To MEA Sec. 95.6001 VICTOR ROUTES-U.S. Sec. 95.6001 VOR FEDERAL AIRWAY V1 IS... *2500--MOCA *3000--GNSS MEA Sec. 95.6003 VOR FEDERAL AIRWAY V3 IS AMENDED TO READ IN PART MODENA,...

  11. 77 FR 38477 - IFR Altitudes; Miscellaneous Amendments

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-28

    ... & Changeover Points From To MEA MAA Sec. 95.3000 Low Altitude RNAV Routes Sec. 95.3306 RNAV Route T306 is Added... MEA * DME/DME/IRU MEA ROCCY, UT FIX RATTLESNAKE, NM * 22000 45000 VORTAC. * 18000--GNSS MEA * DME/DME/IRU MEA Sec. 95.4148 RNAV Route Q148 is Amended to Read in Part STEVS, WA FIX ZAXUL, WA FIX.. *...

  12. 77 FR 65256 - IFR Altitudes; Miscellaneous Amendments

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-26

    ... & Changeover Points From To MEA MAA Sec. 95.4000 HIGH ALTITUDE RNAV ROUTES Sec. 95.4062 RNAV ROUTE Q62 Is... MEA Sec. 95.6001 VICTOR ROUTES--U.S. Sec. 95.6001 VOR FEDERAL AIRWAY V1 Is Amended to Read in Part...--MOCA *2700--GNSS MEA DES MOINES R-105 UNUSABLE, USE OTTUMWA R-287 BUSSY, IA FIX OTTUMWA, IA...

  13. 77 FR 50909 - IFR Altitudes; Miscellaneous Amendments

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-23

    ... From To MEA MAA Sec. 95.3000 Low Altitude RNAV Routes Sec. 95.3310 RNAV Route T310 Is Amended To Read... From To MEA Sec. 95.6001 Victor Routes-U.S. Sec. 95.6001 VOR Federal Airway V1 Is Amended To Read in... V10 Is Amended To Read in Part Emporia, KS VORTAC Wetzl, KS FIX *5000 *2600--MOCA *3000--GNSS...

  14. 76 FR 21622 - IFR Altitudes; Miscellaneous Amendments

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-18

    ... Changeover Points From To MEA MAA Sec. 95.3000 Low Altitude RNAV Routes Sec. 95.3231 RNAV Route T231 Is... *18000--GNSS MEA DME/DME/IRU MEA ZORUN, NV FIX GALLI, NV FIX *2 45000 4000 *18000--GNSS MEA DME/DME/IRU MEA GALLI, NV FIX BIG PINEY, WY VOR/DME *2 45000 3000 *18000--GNSS MEA DME/DME/IRU MEA BIG PINEY,...

  15. 78 FR 57472 - IFR Altitudes; Miscellaneous Amendments

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-19

    ... & Changeover Point From To MEA MAA Sec. 95.3000 Low Altitude RNAV Routes Sec. 95.3212 RNAV Route T212 Is... Is Amended To Read in Part FAREV, KY WP JEDER, KY WP *18000 45000 *18000--GNSS MEA *DME/DME/IRU MEA Sec. 95.4436 RNAV Route Q436 Is Added To Read EMMMA, MI FIX DIXSN, MI WP *18000 45000 *18000--GNSS...

  16. 78 FR 44874 - IFR Altitudes; Miscellaneous Amendments

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-25

    ... Point From To MEA MAA Sec. 95.3000 Low Altitude RNAV Routes Sec. 95.3291 RNAV Route T291 Is Added To...--GNSS MEA *DME/DME/IRU MEA KOATA, OR WP KIMBERLY, OR VORTAC *29000 45000 *18000--GNSS MEA *DME/DME/IRU MEA Sec. 95.4068 RNAV Route Q68 Is Added To Read CHARLESTON, WV VORTAC TOMCA, WV WP *18000...

  17. 78 FR 9583 - IFR Altitudes; Miscellaneous Amendments

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-11

    ... Changeover Points FROM TO MEA MAA Sec. 95.3000 Low Altitude RNAV Routes Sec. 95.3254 RNAV Route T254 is... 3000 15000 FROM TO MEA MAA --------- Sec. 95.6001 Victor Routes-U.S. Sec. 95.6010 VOR Federal Airway V10 is Amended to Read in Part REVLOC, PA VOR/DME JUNEY, PA FIX........ *5000 *5000--GNSS MEA...

  18. 78 FR 32979 - IFR Altitudes; Miscellaneous Amendments

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-03

    ... & Changeover Points Amendment 507 Effective Date June 27, 2013 From To MEA Sec. 95.1001 DIRECT ROUTES--U.S... River, AK NDB..... *7000 *6000-MOCA ] From To MEA MAA Sec. 95.3000 Low Altitude RNAV Routes Sec. 95.3266... *6000-MOCA From To MEA Sec. 95.6001 VICTOR ROUTES--U.S. Sec. 95.6003 VOR Federal Airway V3 Is Amended...

  19. 75 FR 24790 - IFR Altitudes; Miscellaneous Amendments

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-06

    ... From To MEA Sec. 95.1001 Direct Routes-U.S. Color Routes Sec. 95.510 GREEN Federal Airway G10 is... Requred Below 8000 From To MEA MAA Sec. 95.3000 Low Altitude RNAV Routes Sec. 95.3254 RNAV Route T254 is... Crepo, TX FIX Lake Charles, LA VORTAC 2200 15000 ] From To MEA Sec. 95.6001 Victor Routes-U.S. Sec....

  20. 75 FR 82228 - IFR Altitudes; Miscellaneous Amendments

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-30

    ... From To MEA MAA Sec. 95.3000 Low Altitude RNAV Routes Sec. 95.3227 RNAV Route T227 Is Amended To Read... Route Q8 Is Amended To Read in Part Galena, AK VOR/DME Anchorage, AK VOR/DME 18000 45000 From To MEA Sec..., OH VOR/DME Morow, OH FIX 3100 Morow, OH FIX Hires, OH FIX *5000 *2700--MOCA *3000--GNSS MEA Hires,...

  1. 75 FR 52437 - IFR Altitudes; Miscellaneous Amendments

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-26

    ... amended to read as follows: Revisions to IFR Altitudes & Changeover Points From To MEA MAA Sec. 95.3000... Read in Part WALNUT RIDGE, AR VORTAC DEVAC, AL FIX *20000 33000 *18000--GNSS MEA *DME/DME/IRU MEA From To MEA Sec. 95.6001 Victor Routes-U.S. Sec. 95.6003 VOR Federal Airway V3 Is Amended To Read in...

  2. 76 FR 46202 - IFR Altitudes; Miscellaneous Amendments

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-02

    ... Amendment 495 Effective Date August 25, 2011 From To MEA MAA Sec. 95.3000 Low Altitude RNAV Routes Sec. 95... 2000 17500 Borke, NJ FIX Banka, NJ FIX 2000 17500 From To MEA Sec. 95.6001 Victor Routes--U.S. Sec. 95... Airway V36 Is Amended To Read in Part Elmira, NY VOR/DME..... Hawly, PA FIX * 4500 * GNSS MEA. Elmira...

  3. 77 FR 14269 - IFR Altitudes; Miscellaneous Amendments

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-09

    ... Points From To MEA MAA Sec. 95.3000 Low Altitude RNAV Routes Sec. 95.3223 RNAV Route T223 Is Amended to... 18000 45000 GNSS REQUIRED From To MEA Sec. 95.6001 Victor Routes--U.S. Sec. 95.6002 VOR Federal Airway... Amended to Read in Part SERTS, OK FIX LIONS, OK FIX *4500 *3100--MOCA *3700--GNSS MEA LIONS, OK FIX...

  4. High Altitude Cooking and Food Safety

    MedlinePlus

    ... Administrative Forms Standard Forms Skip Navigation Z7_0Q0619C0JGR010IFST1G5B10H1 Web Content Viewer (JSR 286) Actions ${title} Loading... / Topics / ... High Altitude Cooking and Food Safety Z7_0Q0619C0JGR010IFST1G5B10H3 Web Content Viewer (JSR 286) Actions ${title} Loading... Z7_ ...

  5. Altitude Compensating Nozzle Cold Flow Test Results

    NASA Technical Reports Server (NTRS)

    Ruf, J. H.; McDaniels, D. M.

    2002-01-01

    A suite of four altitude compensating nozzle (ACN) concepts were evaluated by NASA MSFC in the Nozzle Test Facility. The ACN concepts were a dual bell, a dual expander, an annular plug nozzle and an expansion deflection nozzle. Two reference bell nozzles were also tested. Axial thrust and nozzle wall static pressures were measured for each nozzle over a wide range of nozzle pressure ratios. The nozzle hardware and test program are described. Sample test results are presented.

  6. Guide to Altitude Decompression Sickness Research

    DTIC Science & Technology

    2010-05-01

    altitude exposure ONLY. Subjects were not given a Physiological Training Card (AF Form 1274; orange ) after completion of this training. Successful...remove any user-installed programs such as x-form. 5) Turn on the arm power by rotating the arm power switch to the right. The orange light will...that results of these breath, blood and/or urine tests shall be made available to the Company and its designated employees or agents . THE

  7. Limiting factors for exercise at extreme altitudes.

    PubMed

    West, J B

    1990-05-01

    Man can only survive and do work in the severe oxygen deprivation of great altitudes by an enormous increase in ventilation which has the advantage of defending the alveolar PO2 against the reduced inspired PO2. Nevertheless the arterial PO2 on the summit of Mt Everest at rest is less than 30 Torr, and it decreases with exercise because of diffusion limitation within the lung. One of the consequences of the hyperventilation is that the marked respiratory alkalosis increases the oxygen affinity of the haemoglobin and assists in loading of oxygen by the pulmonary capillary. Although ventilation is greatly increased, it is a paradox that cardiac output for a given work level is the same in acclimatized subjects at high altitude as at sea level. Stroke volume is reduced but not because of impaired myocardial contractility because this is preserved up to extreme altitudes. Indeed the normal myocardium is one of the few tissues whose function is unimpaired by the very severe hypoxia. There is evidence that oxygen delivery to exercising muscle is diffusion limited along the pathway between the peripheral capillary and the mitochondria. At the altitude of Mt Everest, maximal oxygen uptake is reduced to 20-25% of its sea level value, and it is exquisitely sensitive to barometric pressure. Seasonal variations of barometric pressure affect the ability of man to reach the summit without supplementary oxygen. In spite of the greatly reduced aerobic capacity, anaerobiosis is greatly curtailed, and it is predicted that above 7500 m, there is no rise in blood lactate on exercise. The paradoxically low lactate is possibly related to plasma bicarbonate depletion.

  8. Relative Match Intensities at High Altitude in Highly-Trained Young Soccer Players (ISA3600)

    PubMed Central

    Buchheit, Martin; Hammond, Kristal; Bourdon, Pitre C.; Simpson, Ben M.; Garvican-Lewis, Laura A.; Schmidt, Walter F.; Gore, Christopher J.; Aughey, Robert J.

    2015-01-01

    To compare relative match intensities of sea-level versus high-altitude native soccer players during a 2-week camp at 3600 m, data from 7 sea-level (Australian U17 National team, AUS) and 6 high-altitude (a Bolivian U18 team, BOL) native soccer players were analysed. Two matches were played at sea-level and three at 3600 m on Days 1, 6 and 13. The Yo-Yo Intermittent recovery test (vYo-YoIR1) was performed at sea-level, and on Days 3 and 10. Match activity profiles were measured via 10-Hz GPS. Distance covered >14.4 km.h-1 (D>14.4 km·h-1) and >80% of vYo-YoIR1 (D>80%vYo-YoIR1) were examined. Upon arrival at altitude, there was a greater decrement in vYo-YoIR1 (Cohen’s d +1.0, 90%CL ± 0.8) and D>14.4 km·h-1 (+0.5 ± 0.8) in AUS. D>14.4 km.h-1 was similarly reduced relative to vYo-YoIR1 in both groups, so that D>80%vYo-YoIR1 remained similarly unchanged (-0.1 ± 0.8). Throughout the altitude sojourn, vYo-YoIR1 and D>14.4 km·h-1 increased in parallel in AUS, so that D>80%vYo-YoIR1 remained stable in AUS (+6.0%/match, 90%CL ± 6.7); conversely D>80%vYo-YoIR1 decreased largely in BOL (-12.2%/match ± 6.2). In sea-level natives competing at high-altitude, changes in match running performance likely follow those in high-intensity running performance. Bolivian data confirm that increases in ‘fitness’ do not necessarily translate into greater match running performance, but rather in reduced relative exercise intensity. Key points When playing at high-altitude, players may alter their activities during matches in relation to their transient maximal physical capacities, possibly to maintain a ‘tolerable’ relative exercise intensity. While there is no doubt that running performance per se in not the main determinant of match outcomes (Carling, 2013), fitness levels influence relative match intensity (Buchheit et al., 2012, Mendez-Villanueva et al., 2013), which in-turn may impact on decision making and skill performance (Rampinini et al., 2008). In the context of

  9. Photographer : JPL Range : 106,250,000 km. ( 66 million miles) P-22830C This, Voyager 1 image shows

    NASA Technical Reports Server (NTRS)

    1980-01-01

    Photographer : JPL Range : 106,250,000 km. ( 66 million miles) P-22830C This, Voyager 1 image shows Saturn and three of its satellites. A series of dark and light cloud bands appears through high altitude haze in the northern hemisphere. Cosiderable structure can be seen in the rings. The Cassini division, between the A-ring and B-ring, is readily visible. The shadow of rings on the planet's disk can also be seeen. The three satellites visible are, left to right, Enceladus (off the left edge of rings), Dione (just below the planet), and Tethys (at right edge of frame). The spacecraft will make its closest approach, 124,200 km. (77,174 miles) abovr the cloud tops, at 3:45 pm PST on Nov. 12, 1980. Nine months later, in August 1981, Voyager 2 will encounter Saturn and then continue on to Uranus.

  10. The effect of altitude on welding

    SciTech Connect

    Liu, S.; Olson, D.L.

    1996-12-31

    Welding at high altitude has typically been reported as more difficult, particularly in the aspect of porosity control. As a consequence, welding of a similar assembly in cities of high elevation such as Denver, Colorado (USA) and Mexico City (Mexico) may require different parameters from those selected for welding in Houston, Texas (USA), Kobe (Japan), and Hamburg (Germany). The atmospheric pressures in these locations are different and the solubilities of bases such as hydrogen in the weld metal are also expected to be different. In this work, the formation of hydrogen and carbon monoxide porosity in low carbon steel weld metals was investigated. The thermodynamic conditions of the chemical reactions that occur in the weld poor were examined. The effects of ambient pressure on the H-O and C-O reactions were estimated for a range of pressures that varied from sea level to approximately 10,000 feet elevation. It was determined that the amounts of carbon monoxide and water in the pores varied measurably with altitude. Since the water vapor molecules that are entrapped in a pore react favorably with the iron atoms on the surface of the pore to form hydrogen and iron oxide, the amount of retained carbon monoxide and hydrogen would also vary with altitude. Finally, welds performed at lower ambient pressure (in locations of higher elevation) are expected to exhibit a larger amount of porosity because of reaction thermodynamics and nucleation kinetics.

  11. Use of ultrasound in altitude decompression modeling

    NASA Technical Reports Server (NTRS)

    Olson, Robert M.; Pilmanis, Andrew A.

    1993-01-01

    A model that predicts the probability of developing decompression sickness (DCS) with various denitrogenation schedules is being developed by the Armstrong Laboratory, using human data from previous exposures. It was noted that refinements are needed to improve the accuracy and scope of the model. A commercially developed ultrasonic echo imaging system is being used in this model development. Using this technique, bubbles images from a subject at altitude can be seen in the gall bladder, hepatic veins, vena cava, and chambers of the heart. As judged by their motion and appearance in the vena cava, venous bubbles near the heart range in size from 30 to 300 M. The larger bubbles skim along the top, whereas the smaller ones appear as faint images near the bottom of the vessel. Images from growing bubbles in a model altitude chamber indicate that they grow rapidly, going from 20 to 100 M in 3 sec near 30,000 ft altitude. Information such as this is valuable in verifying those aspects of the DCS model dealing with bubble size, their growth rate, and their site of origin.

  12. The High Altitude Water Cherenkov Observatory

    NASA Astrophysics Data System (ADS)

    Mostafa, Miguel; HAWC Collaboration

    2016-03-01

    The High Altitude Water Cherenkov (HAWC) Observatory is a continuously operated, wide field of view experiment comprised of an array of 300 water Cherenkov detectors (WCDs) to study transient and steady emission of TeV gamma and cosmic rays. Each 200000 l WCD is instrumented with 4 PMTs providing charge and timing information. The array covers ~22000 m2 at an altitude of 4100 m a.s.l. inside the Pico de Orizaba national park in Mexico. The high altitude, large active area, and optical isolation of the PMTs allows us to reliably estimate the energy and determine the arrival direction of gamma and cosmic rays with significant sensitivity over energies from several hundred GeV to a hundred TeV. Continuously observing 2 / 3 of the sky every 24 h, HAWC plays a significant role as a survey instrument for multi-wavelength studies. The performance of HAWC makes possible the detection of both transient and steady emissions, the study of diffuse emission and the measurement of the spectra of gamma-ray sources at TeV energies. HAWC is also sensitive to the emission from GRBs above 100 GeV. I will highlight the results from the first year of operation of the full HAWC array, and describe the ongoing site work to expand the array by a factor of 4 to explore the high energy range.

  13. Altitude and arteriolar hyalinosis after kidney transplantation.

    PubMed

    Cippà, Pietro E; Grebe, Scott O; Fehr, Thomas; Wüthrich, Rudolf P; Mueller, Thomas F

    2016-09-01

    The kidney is very susceptible to hypoxic injury. Calcineurin inhibitors (CNIs) induce vasoconstriction and might reduce renal tissue oxygenation. We aimed to investigate if the synergistic deleterious effects of CNI-treatment and hypoxia of high altitude living might accelerate the development of arteriolar hyalinosis in kidney allografts. We stratified all patients who received a kidney graft from 2000 to 2010 in our centre (n = 477) in three groups according to the residential elevation (below 400, between 400 to 600 and above 600 m above sea level) and we retrospectively re-evaluated all transplant biopsies performed during follow-up, specifically looking at the degree of arteriolar hyalinosis, the hallmark of chronic CNI nephrotoxicity. Living at high altitude was markedly associated with a higher degree of arteriolar hyalinosis (P < 0.001). Haemoglobin levels confirmed the functional relevance of different arterial oxygenation among the groups (P = 0.01). Thus, patients living at high altitude seem to be more susceptible to the development of arteriolar hyalinosis after kidney transplantation.

  14. Rationale and operational plan for a U.S. high-altitude magnetic survey

    USGS Publications Warehouse

    Hildenbrand, Thomas G.; Acuna, Mario; Bracken, Robert E.; Hardwick, Doug; Hinze, William J.; Keller, Gordon R.; Phillips, Jeff; Roest, Walter

    2002-01-01

    On August 8, 2002, twenty-one scientists from the federal, private and academic sectors met at a workshop in Denver, Co., to discuss the feasibility of collecting magnetic anomaly data on a Canberra aircraft (Figure 1). The need for this 1-day workshop arose because of an exciting and cost-effective opportunity to collect invaluable magnetic anomaly data during a Canberra mission over the U.S. in 2003 and 2004. High Altitude Mapping Missions (HAMM) is currently planning a mission to collect Interferometric Synthetic Aperture Radar (IFSAR) imagery at an altitude of about 15 km and with a flight-line spacing of about 18 km over the conterminous U.S. and Alaska. The additional collection of total and vector magnetic field data would represent a secondary mission objective (i.e., a "piggy-back" magnetometer system). Because HAMM would fund the main flight costs of the mission, the geomagnetic community would obtain invaluable magnetic data at a nominal cost. These unique data would provide new insights on fundamental tectonic and thermal processes and give a new view of the structural and lithologic framework of the crust and possibly the upper mantle. This document highlights: (1) the reasons to conduct this national survey and (2) a preliminary operational plan to collect high-altitude magnetic data of a desired quality and for the expected resources. Although some operational plan issues remain to be resolved, the important conclusions of the workshop are that the Canberra is a very suitable platform to measure the magnetic field and that the planned mission will result in quality high-altitude magnetic data to greatly expand the utility of our national magnetic database.

  15. Mercury's Crustal Magnetic Field from Low-Altitude Measurements by MESSENGER.

    NASA Astrophysics Data System (ADS)

    Johnson, C. L.; Phillips, R. J.; Purucker, M. E.; Anderson, B. J.; Byrne, P. K.; Denevi, B. W.; Fan, K. A.; Feinberg, J. M.; Hauck, S. A., II; Head, J. W., III; Korth, H.; James, P. B.; Mazarico, E.; Neumann, G. A.; Philpott, L. C.; Siegler, M. A.; Strauss, B. E.; Tsyganenko, N. A.; Solomon, S. C.

    2015-12-01

    Magnetized rocks can record the history of a planet's magnetic field, a key constraint for understanding interior evolution. From orbital vector magnetic field measurements of Mercury taken by the MESSENGER spacecraft at altitudes below 150 km, we have detected fields indicative of crustal magnetization. Fields from non-crustal sources, which dominate the observations even at low altitudes, were estimated and subtracted from the observations using both magnetospheric models and signal filtering. The resulting high-pass filtered fields have amplitudes of a few to 20 nT. The first low-altitude signals were detected over the Suisei Planitia region and were confirmed by upward continuation to be of crustal origin. At least some contribution from thermoremanent magnetization is required to account for these signals, and we infer a lower bound on the average age of magnetization of 3.7-3.9 Ga on the basis of correlation of crustal magnetic fields with volcanic units of that age range. Ancient field strengths that range from those similar to Mercury's present dipole field to Earth-like values are consistent with the magnetic field observations and with the low iron content of Mercury's crust derived from MESSENGER elemental composition data. Here, we extend these initial results with observations obtained at spacecraft altitudes below 60 km at all body-fixed longitudes from ~40°N to ~75°N. The strongest crustal fields occur in the region 120°E to 210°E, and weaker signals characterize the northern volcanic plains. We test the hypothesis that the longest-wavelength crustal field signals in this region reflect magnetization contrasts between the Caloris basin and the surrounding intercrater plains and circum-Caloris plains. We report the spatial distribution of observed crustal fields, together with magnetization models derived from them and the implications of these models, particularly for the depth distribution of sources compatible with the observations.

  16. Linear and Nonlinear Infrasound Propagation to 1000 km

    DTIC Science & Technology

    2015-12-15

    to their average sea level values and the ambient temperature is set to 15oC, giving a static sound speed of 340 m/s. The source is centered at an...alters the governing equations, but results in quantifiable dispersion characteristics. It is shown that this method leaves sound speeds and...2. Profiles of a) density, b) sound speed, and c) attenuation as a function of altitude -- 13 3. FDTD Pressure fluctuation snapshots, with

  17. Wave-Like Perturbations Observed at Low Altitudes by the Pioneer Venus Orbiter Neutral Mass Spectrometer During Orbiter Entry

    NASA Technical Reports Server (NTRS)

    Kasprzak, W. T.; Niemann, H. B.; Hedin, A. E.; Bougher, S. W.

    1993-01-01

    Wave-like perturbations have been observed in the nightside neutral density data acquired for He, N, O, N2 and CO2 by the Pioneer Venus Orbiter Neutral Mass Spectrometer (ONMS) during entry in late 1992. The data cover an altitude range of 133-200 km from 0.5-4.5 hours local solar time and occur at medium solar activity (F(sub 10.7) = 120) The perturbations, with an effective wavelength along the orbit of about 100 to 600 km, have similar amplitudes for the various species and helium is out of phase with respect to the heavier mass species. The measurements are comparable to those observed in 1978-80 at solar maximum activity (F(sub 10.7) = 200) above 145 km. Between 133 and 160 km the rms amplitudes grow with altitude at a rate of about (1.6, 2.1, 2.7, 4.4) x 10(exp -3)/ km for N, O, N2, and CO2 respectively. The average rms amplitudes above 145 km of 0.08 for N and O and 0.1 for N2 are comparable in magnitude to those observed in the earlier 1978-80 data of 0.06, 0.08 and 0.095 respectively. CO2 is an exception for which the entry value is 0.17 compared to 0.09 earlier. By combining the two overlapping data sets there is a suggestion that the CO2 amplitudes grow in value with altitude up to about 140-170 km and then decrease in amplitude. Like the earlier data, the entry data are consistent with the interpretation that the neutral density perturbations are due to gravity waves propagating upward from the lower thermosphere. Earlier data sampled a higher altitude region where dissipation is important in limiting and ultimately reversing the growth of gravity waves while the lower altitude entry data probed the region where growth of these waves can be observed.

  18. Growth of Han migrants at high altitude in central Asia.

    PubMed

    Weitz, Charles A; Garruto, Ralph M

    2004-01-01

    Han Chinese of low-altitude descent have been living in Qinghai Province of Western China for at least two millennia. For most of this time they have lived at elevations under 2,500 m. However, during the last four decades an increasing number of Han have moved into high-altitude towns at elevations over 3,000 m, and some above 4,000 m. There are now sufficient numbers of Han descendants who have been born and raised at high altitude to allow a comparison of their morphological and physiological growth patterns with low-altitude Han to detect the effect of hypoxia. The field study reported here was conducted by collaborating Chinese and American researchers over a 6-year period, and included 1,227 Han living at high altitude in Qinghai and at low altitude near Beijing. This study demonstrates that Han born and raised at high altitude are smaller and lighter than those at low altitude-particularly as children and adolescents. Slower growth at high altitude may be a consequence of hypoxia, but it also corresponds to poorer economic conditions in rural Qinghai Province, and thus may reflect nutritional inadequacies. Differences in altitude and/or nutrition do not seem to affect thorax dimensions, since, relative to stature, chest dimensions are similar at both high and low altitudes. Nevertheless, lung volumes are higher among Han at high altitude, possibly reflecting the influence of hypoxia on alveolar growth. The hematological values of Han growing up at 3,200 m are not different from those at low altitude-an unusual finding relative to other low-altitude groups that may reflect population differences in response to hypoxia. At 3,800 m and 4,300 m, however, Han show elevated hemoglobin relative to Han at low altitude.

  19. 41 CFR 304-3.13 - After I begin travel to a meeting, what should I do if a non-Federal source offers to pay for one...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 41 Public Contracts and Property Management 4 2012-07-01 2012-07-01 false After I begin travel to... expenses without my or my agency's prior knowledge? 304-3.13 Section 304-3.13 Public Contracts and Property Management Federal Travel Regulation System PAYMENT OF TRAVEL EXPENSES FROM A NON-FEDERAL SOURCE...

  20. The peak altitude of H3+ auroral emission: comparison with the ultraviolet

    NASA Astrophysics Data System (ADS)

    Blake, J.; Stallard, T.; Miller, S.; Melin, H.; O'Donoghue, J.; Baines, K.

    2013-09-01

    The altitude of Saturn's peak auroral emission has previously been measured for specific cases in both the ultraviolet (UV) and the infrared (IR). Gerard et al [2009] concludes that the night side H2 UV emission is within the range of 800 to 1300 km above the 1-bar pressure surface. However, using colour ratio spectroscopy, Gustin et al [2009] located the emission layer at or above 610 km. Measurements of the infrared auroral altitude was conducted by Stallard et al [2012] on H3+ emissions from nine VIMS Cassini images, resulting in a measurement of 1155 ± 25 km above the 1-bar pressure surface. Here we present data analysed in a manner similar to Stallard et al [2012] on the observations of H3+ emission in twenty images taken by the Visual Infrared Mapping Spectrometer (VIMS) aboard the spacecraft Cassini from the years 2006, 2008 and 2012. The bins covered were 3.39872, 3.51284, 3.64853, 4.18299 and 4.33280 μm. These observations were selected from a set of 15,000 as they contained a useful alignment of the aurorae on the limb and the body of the planet. The specific conditions that had to be met for each image were as follows; minimum integration time of 75 milliseconds per pixel, minimum number of pixels in the x and y direction of 32, the image must include the latitude range of 70 to 90 degrees for either hemisphere and the sub spacecraft angle must be between 0 and 20 degrees. This alignment allowed for the altitudinal profiles to be analysed in terms of the difference between the latitude of aurorae on the limb and on the body of Saturn; thus permitting an investigation into the effects of misalignment. In this instance, misalignment was defined as the difference between the latitude of the peak emission latitude on the planet and the latitude of the limb; assuming the aurorae to be approximately circular. A statistical study by Badman et al [2011] showed that centre of the oval is on average offset anti sunward of the pole by about 1.6 degrees. To

  1. Global Trends in Glacial Cirque Floor Altitudes and Their Relationships with Climate, Equilibrium Line Altitudes, and Mountain Range Heights

    NASA Astrophysics Data System (ADS)

    Mitchell, S. G.; Humphries, E.

    2013-12-01

    Glacial erosion at the base of cirque headwalls and the creation of threshold slopes above cirque floors may contribute to the 'glacial buzzsaw' effect in limiting the altitude of some mountain ranges. Since glacial extent and therefore glacial erosion rate depends on the equilibrium line altitude (ELA) of a region, the altitude of cirque formation should be a function of the ELA. Several regional studies have shown that cirque floors form at an altitude approximating average Quaternary ELAs in some mountain ranges, but a global correlation has not yet been demonstrated. We examined the correlation between cirque altitudes and global ELA trends by compiling existing and new cirque altitude and morphometry data from > 30 mountain ranges at a wide range of latitudes. Where available, we calculate or present the average cirque altitude, relief, and latitude. We compared these altitudes to both the global East Pacific ELA and local ELAs where available. For the locations analyzed, the majority of average cirque altitudes fall between the Eastern Pacific modern and LGM ELAs, and mountain range height is typically limited to < 600 m above that altitude. This evidence supports the hypothesis that cirque formation is dependent upon the ELA, and that cirques likely form as a result of average, rather than extreme, glacial conditions. Furthermore, the correlation between cirque altitude and ELA, along with the restricted window of relief, implies that cirque formation is a factor in limiting peak altitude in ranges that rise above the ELA.

  2. Interplanetary dust particles, not wind blown dust, control high altitude ice clouds on Mars

    NASA Astrophysics Data System (ADS)

    Hartwick, Victoria; Toon, Owen B.

    2016-10-01

    Water ice clouds on Mars are commonly observed at high altitudes. However, current generation Mars three-dimensional general circulation models (GCM) struggle to reproduce clouds above approximately 20-30 km. On Mars, as on Earth, ice cloud formation likely initiates by heterogeneous nucleation, which requires a population of suspended ice nuclei contiguous with supersaturated atmospheric water vapor. Although supersaturation is observed at high altitudes and has been reproduced in models, models predict very few ice nuclei. The small number of ice nuclei in the upper atmosphere is due to the assumption in Mars GCMs that the only source of ice nuclei is dust from the Martian surface. However, terrestrial mesospheric noctilucent clouds have been shown to form by ice nucleation on particles originating from ablated micrometeroids. Therefore, it is reasonable to assume that a population of micrometeoric ablation biproducts on Mars exists and can act as a site for cloud nucleation at high altitudes. We present simulations using the Community Atmosphere Model for Mars (MarsCAM) based on the National Center for Atmospheric Research (NCAR) Community Atmosphere Model for Earth,coupled with a physically based, state-of-the-art cloud and dust physics model, the Community Aerosol and Radiation Model for Atmospheres (CARMA) to show that ablating micrometeoroids can yield abundant ice nuclei throughout the upper atmosphere of Mars. We find that simulations including a constant annual micrometeoroid flux allows us to reproduce the observed properties of high altitude water ice clouds including vertical distribution and particle size. In general, effective radius decreases with increasing altitude. We have additionally explored the impact of variable ablation rates. Preliminary results suggest that relatively high ablation rates, near or greater than 50%, are required to reproduce observed cloud features.

  3. Intensity of nightside MARSIS AIS surface reflections and implications for low-altitude ionospheric densities

    NASA Astrophysics Data System (ADS)

    Němec, F.; Morgan, D. D.; Diéval, C.; Gurnett, D. A.

    2015-04-01

    Spacecraft radar sounding signals at frequencies higher than the ionospheric peak plasma frequency are not reflected by the ionosphere. Instead, they make it to the ground where they are reflected by the planetary surface. We analyze the intensity of the surface reflections measured by the Mars Advanced Radar for Subsurface and Ionosphere Sounding (MARSIS) ionospheric radar sounder on board the Mars Express spacecraft. Apart from the surface reflectivity and the spacecraft altitude, the detected intensity of surface reflections is controlled primarily by the signal attenuation during the ionospheric propagation. We focus on the nightside region, where the ionospheric densities in the main layer are too low to cause a significant attenuation and allow sampling of the surface reflections at frequencies down to 3 MHz. The attenuation occurs mainly at altitudes below 100 km, where the electron-neutral collision frequency is a maximum. The intensity of surface reflections can thus serve as a proxy for electron densities at low altitudes not accessible by the direct ionospheric radar sounding. We analyze the intensity of surface reflections as a function of relevant controlling parameters. The intensity of surface reflections is lower at higher solar zenith angles on the nightside and during the periods of larger solar activity. Moreover, it exhibits a seasonal variation that is related to the dust storm occurrence. The intensity of surface reflections is lower in areas of closed magnetic field lines, suggesting that nightside electron densities behave rather differently at low altitudes than at higher altitudes. This is confirmed by comparison with simultaneous observations of the main ionospheric layer.

  4. A High Altitude Infrared Radiance Model

    DTIC Science & Technology

    1974-12-27

    50 and 100 km using a photochemical model that includes vertical transport by eddy diffusion. In a later paper . Anderson (1971 b) gives a...2 shows a typical nitric oxide concentration curve, based on mid-latitude measurements. While ozone abundances below about 50 km must take into...and 4000 wave numbers. Results are presented here based c/) estimated abundance profiles of the four species C02, H20, 03 and NO. The

  5. Radar-anomalous, high-altitude features on Venus

    NASA Technical Reports Server (NTRS)

    Muhleman, Duane O.; Butler, Bryan J.

    1992-01-01

    Over nearly all of the surface of Venus the reflectivity and emissivity at centimeter wavelengths are about 0.15 and 0.85 respectively. These values are consistent with moderately dense soils and rock populations, but the mean reflectivity is about a factor of 2 greater than that for the Moon and other terrestrial planets. Pettingill and Ford, using Pioneer Venus reflectivities and emissivities, found a number of anomalous features on Venus that showed much higher reflectivities and much lower emissivities with both values approaching 0.5. These include Maxwell Montes, a number of high regions in Aphrodite Terra and Beta Regio, and several isolated mountain peaks. Most of the features are at altitudes above the mean radius by 2 to 3 km or more. However, such features have been found in the Magellan data at low altitudes and the anomalies do not exist on all high structures, Maat Mons being the most outstanding example. A number of papers have been written that attempt to explain the phenomena in terms of the geochemistry balance of weathering effects on likely surface minerals. The geochemists have shown that the fundamentally basaltic surface would be stable at the temperatures and pressures of the mean radius in the form of magnetite, but would evolve to pyrite and/or pyrrhotite in the presence of sulfur-bearing compounds such as SO2. Pyrite will be stable at altitudes above 4 or 5 km on Venus. Although the geochemical arguments are rather compelling, it is vitally important to rationally look at other explanations for radar and radio emission measurements such as that presented by Tryka and Muhleman. The radar reflectivity values are retrieved from the raw Magellan backscatter measurements by fitting the Hagfors' radar scattering model in which a surface roughness parameters and a normal incidence electrical reflectivity are estimated. The assumptions of the theory behind the model must be considered carefully before the results can be believed. These include

  6. Prototype detector development for measurement of high altitude Martian dust using a future orbiter platform

    NASA Astrophysics Data System (ADS)

    Pabari, Jayesh; Patel, Darshil; Chokhawala, Vimmi; Bogavelly, Anvesh

    2016-07-01

    Dust devils mostly occur during the mid of Southern hemisphere summer on Mars and play a key role in the background dust opacity. Due to continuous bombardment of micrometeorites, secondary ejecta come out from the Moons of the Mars and can easily escape. This phenomenon can contribute dust around the Moons and therefore, also around the Mars. Similar to the Moons of the Earth, the surfaces of the Martian Moons get charged and cause the dust levitation to occur, adding to the possible dust source. Also, interplanetary dust particles may be able to reach the Mars and contribute further. It is hypothesized that the high altitude Martian dust could be in the form of a ring or tori around the Mars. However, no such rings have been detected to the present day. Typically, width and height of the dust torus is ~5 Mars radii wide (~16950 km) in both the planes as reported in the literature. Recently, very high altitude dust at about 1000 km has been found by MAVEN mission and it is expected that the dust may be concentrated at about 150 to 500 km. However, a langmuir probe cannot explain the source of such dust particles. It is a puzzling question to the space scientist how dust has reached to such high altitudes. A dedicated dust instrument on future Mars orbiter may be helpful to address such issues. To study origin, abundance, distribution and seasonal variation of Martian dust, a Mars Orbit Dust Experiment (MODEX) is proposed. In order to measure the Martian dust from a future orbiter, design of a prototype of an impact ionization dust detector has been initiated at PRL. This paper presents developmental aspects of the prototype dust detector and initial results. The further work is underway.

  7. Evaluating KM Journal Content: An Assessment of Trends (2000-2005)

    DTIC Science & Technology

    2006-03-01

    Creating a KM Systems Thinking Framework...........................................................17 What is a KM-specific Journal...loop Learning ................................................................... 27 Figure 6. Combining KM Frameworks into a KM Systems Thinking Framework...30 Figure 7. KM Systems Thinking Framework .................................................................. 31 Figure 8. Content

  8. Lightning leader altitude progression in terrestrial gamma-ray flashes

    NASA Astrophysics Data System (ADS)

    Cummer, Steven A.; Lyu, Fanchao; Briggs, Michael S.; Fitzpatrick, Gerard; Roberts, Oliver J.; Dwyer, Joseph R.

    2015-09-01

    Radio emissions continue to provide insight into the production of terrestrial gamma ray flashes (TGFs) by thunderstorms, including the critical question of the conditions under which they are generated. We have identified several TGF-associated lightning radio emissions in which the altitudes of in-cloud lightning leader pulses that precede and follow the TGF can be measured. We combine these with high absolute timing accuracy TGF observations from the Fermi satellite to determine the development of the lightning channel before, during, and after the TGF production. All of these TGFs were produced several milliseconds after the leader had initiated and when the leaders reached 1-2 km in length. After the TGFs, the leaders all continued to ascend for several more kilometers with no dramatic change in their characteristics, although they all exhibited high average velocities of 0.8-1.0 × 106 m/s. Implications in the context of TGF models are discussed. These results paint the first clear picture of the lightning processes that occur before, during, and after TGF production.

  9. Medium altitude airborne Geiger-mode mapping LIDAR system

    NASA Astrophysics Data System (ADS)

    Clifton, William E.; Steele, Bradley; Nelson, Graham; Truscott, Antony; Itzler, Mark; Entwistle, Mark

    2015-05-01

    Over the past 15 years the Massachusetts Institute of Technology, Lincoln Laboratory (MIT/LL), Defense Advanced Research Projects Agency (DARPA) and private industry have been developing airborne LiDAR systems based on arrays of Geiger-mode Avalanche Photodiode (GmAPD) detectors capable of detecting a single photon. The extreme sensitivity of GmAPD detectors allows operation of LiDAR sensors at unprecedented altitudes and area collection rates in excess of 1,000 km2/hr. Up until now the primary emphasis of this technology has been limited to defense applications despite the significant benefits of applying this technology to non-military uses such as mapping, monitoring critical infrastructure and disaster relief. This paper briefly describes the operation of GmAPDs, design and operation of a Geiger-mode LiDAR, a comparison of Geiger-mode and traditional linear mode LiDARs, and a description of the first commercial Geiger-mode LiDAR system, the IntelliEarth™ Geospatial Solutions Geiger-mode LiDAR sensor.

  10. Bursts of transverse ion acceleration at rocket altitudes

    NASA Technical Reports Server (NTRS)

    Arnoldy, R. L.; Lynch, K. A.; Kintner, P. M.; Vago, J.; Chesney, S.; Moore, T. E.; Pollock, C. J.

    1992-01-01

    High-time-resolution ion mass spectrometer distribution function measurements and wave data from a sounding rocket flight over an aurora have revealed the fine structure of the transverse ion acceleration mechanism in the upper ionosphere. The transversely accelerated ion (TAI) events can occur in a volume with a cross-field dimension as small as several tens of meters and thus appear as 50-100 ms ion bursts due to the rocket payload motion. Bulk heating to a characteristic energy of several eV and tail heating in the direction perpendicular to B of a few percent of ambient ions to a characteristic energy the order of 10 eV occur for both hydrogen and oxygen ions. The TAI at 90 deg pitch angle occur in localized regions of intense lower hybrid waves and in regions of density depletion. On close examination of the correlation between the wave bursts and the TAI it is believed that the waves produce the ion acceleration. The TAI occur during periods of field-aligned auroral electron bursts. Finally, near 1000 km altitude they occur about once every second. If the event presented here is considered average, the flux of TAI oxygen ions above 7 eV could account for the ion conic fluxes measured by the ISIS spacecraft.

  11. High energy neutrino detection with KM3NeT

    NASA Astrophysics Data System (ADS)

    Migliozzi, Pasquale; KM3NeT Collaboration

    2016-05-01

    The KM3NeT Collaboration has started the construction of a next generation high-energy neutrino telescope in the Mediterranean Sea: the largest and most sensitive neutrino research infrastructure. The full KM3NeT detector will be a several cubic kilometres distributed, networked infrastructure. In Italy, off the coast of Capo Passero, and in France, off the coast of Toulon. Thanks to its location in the Northern hemisphere and to its large instrumented volume, KM3NeT will be the optimal instrument to search for neutrinos from the Southern sky and in particular from the Galactic plane, thus making it complementary to IceCube. In this work the technologically innovative component of the detector, the status of construction and the first results from prototypes of the KM3NeT detector will be described as well as its capability to discover neutrino sources are reported.

  12. Akeno 20 km (2) air shower array (Akeno Branch)

    NASA Technical Reports Server (NTRS)

    Teshima, M.; Ohoka, H.; Matsubara, Y.; Hara, T.; Hatano, Y.; Hayashida, N.; He, C. X.; Honda, M.; Ishikawa, F.; Kamata, K.

    1985-01-01

    As the first stage of the future huge array, the Akeno air shower array was expanded to about 20 sq. km. by adding 19 scintillation detectors of 2.25 sq m area outside the present 1 sq. km. Akeno array with a new data collection system. These detectors are spaced about 1km from each other and connected by two optical fiber cables. This array has been in partial operation from 8th, Sep. 1984 and full operation from 20th, Dec. 1984. 20 sq m muon stations are planned to be set with 2km separation and one of them is now under construction. The origin of the highest energy cosmic rays is studied.

  13. High-altitude illnesses: physiology, risk factors, prevention, and treatment.

    PubMed

    Taylor, Andrew T

    2011-01-01

    High-altitude illnesses encompass the pulmonary and cerebral syndromes that occur in non-acclimatized individuals after rapid ascent to high altitude. The most common syndrome is acute mountain sickness (AMS) which usually begins within a few hours of ascent and typically consists of headache variably accompanied by loss of appetite, nausea, vomiting, disturbed sleep, fatigue, and dizziness. With millions of travelers journeying to high altitudes every year and sleeping above 2,500 m, acute mountain sickness is a wide-spread clinical condition. Risk factors include home elevation, maximum altitude, sleeping altitude, rate of ascent, latitude, age, gender, physical condition, intensity of exercise, pre-acclimatization, genetic make-up, and pre-existing diseases. At higher altitudes, sleep disturbances may become more profound, mental performance is impaired, and weight loss may occur. If ascent is rapid, acetazolamide can reduce the risk of developing AMS, although a number of high-altitude travelers taking acetazolamide will still develop symptoms. Ibuprofen can be effective for headache. Symptoms can be rapidly relieved by descent, and descent is mandatory, if at all possible, for the management of the potentially fatal syndromes of high-altitude pulmonary and cerebral edema. The purpose of this review is to combine a discussion of specific risk factors, prevention, and treatment options with a summary of the basic physiologic responses to the hypoxia of altitude to provide a context for managing high-altitude illnesses and advising the non-acclimatized high-altitude traveler.

  14. Study of impact demagnetization at Mars using Monte Carlo modeling and multiple altitude data

    NASA Astrophysics Data System (ADS)

    Lillis, Robert J.; Purucker, Michael E.; Halekas, Jasper S.; Louzada, Karin L.; Stewart-Mukhopadhyay, Sarah T.; Manga, Michael; Frey, Herbert V.

    2010-07-01

    The magnetic field signatures of large demagnetized impact basins on Mars offer a unique opportunity to study the magnetic properties of the crust and the processes of basin formation and impact shock demagnetization. We present a framework for determining the effects on such signatures due to the dominant direction, strength, thickness, and vertical and horizontal coherence wavelengths of the surrounding crustal magnetization, as well as the demagnetization radius and the width of the demagnetization gradient zone caused by impact shock. By comparing model results with observed magnetic field profiles at 185 km and 400 km over the five largest apparently demagnetized impact structures, we find that (1) the dominant lateral size of coherently magnetized regions of crust falls in the range ˜325 km to 600 km, (2) the magnetic field observed over a circular demagnetized region is such that clear demagnetization signatures should only be visible in magnetic field maps at 185 km and 400 km altitude for demagnetization diameters larger than ˜600 km and ˜1000 km, respectively, (3) demagnetization radii can be meaningfully constrained despite relatively poor constraints on associated demagnetization gradient zone widths, (4) the ratio of demagnetization diameter to the outer topographic ring diameter is close to 0.8 for the Isidis, Hellas, Argyre, and Utopia basins, suggesting that similar basin-forming and shock demagnetization processes occurred in each of these four ancient impacts, and (5) if used in conjunction with impact simulations, such modeling may lead to improved constraints on peak pressure contours and impact energies for these basins.

  15. Science requirements and feasibility/design studies of a very-high-altitude aircraft for atmospheric research

    NASA Technical Reports Server (NTRS)

    Russell, Philip B.; Lux, David P.; Reed, R. Dale; Loewenstein, Max; Wegener, Steven

    1991-01-01

    The advantages and shortcomings of currently available aircraft for use in very high altitude missions to study such problems as polar ozone or stratosphere-troposphere exchange pose the question of whether to develop advanced aircraft for atmospheric research. To answer this question, NASA conducted a workshop to determine science needs and feasibility/design studies to assess whether and how those needs could be met. It was determined that there was a need for an aircraft that could cruise at an altitude of 30 km with a range of 6,000 miles with vertical profiling down to 10 km and back at remote points and carry a payload of 3,000 lbs.

  16. Influence of the superposition approximation on calculated effective dose rates from galactic cosmic rays at aerospace-related altitudes

    NASA Astrophysics Data System (ADS)

    Copeland, Kyle

    2015-07-01

    The superposition approximation was commonly employed in atmospheric nuclear transport modeling until recent years and is incorporated into flight dose calculation codes such as CARI-6 and EPCARD. The useful altitude range for this approximation is investigated using Monte Carlo transport techniques. CARI-7A simulates atmospheric radiation transport of elements H-Fe using a database of precalculated galactic cosmic radiation showers calculated with MCNPX 2.7.0 and is employed here to investigate the influence of the superposition approximation on effective dose rates, relative to full nuclear transport of galactic cosmic ray primary ions. Superposition is found to produce results less than 10% different from nuclear transport at current commercial and business aviation altitudes while underestimating dose rates at higher altitudes. The underestimate sometimes exceeds 20% at approximately 23 km and exceeds 40% at 50 km. Thus, programs employing this approximation should not be used to estimate doses or dose rates for high-altitude portions of the commercial space and near-space manned flights that are expected to begin soon.

  17. How does music aid 5 km of running?

    PubMed

    Bigliassi, Marcelo; León-Domínguez, Umberto; Buzzachera, Cosme F; Barreto-Silva, Vinícius; Altimari, Leandro R

    2015-02-01

    This research investigated the effects of music and its time of application on a 5-km run. Fifteen well-trained male long-distance runners (24.87 ± 2.47 years; 78.87 ± 10.57 kg; 178 ± 07 cm) participated in this study. Five randomized experimental conditions during a 5-km run on an official track were tested (PM: motivational songs, applied before 5 km of running; SM: slow motivational songs, applied during 5 km of running; FM: fast and motivational songs, applied during 5 km of running; CS: calm songs, applied after 5 km of running; CO: control condition). Psychophysiological assessments were performed before (functional near-infrared spectroscopy, heart rate variability [HRV], valence, and arousal), during (performance time, heart rate, and rate of perceived exertion [RPE]), and after (mood, RPE, and HRV) tests. The chosen songs were considered pleasurable and capable of activating. Furthermore, they activated the 3 assessed prefrontal cortex (PFC) areas (medial, right dorsolateral, and left dorsolateral) similarly, generating positive emotional consequences by autonomous system analysis. The first 800 m was accomplished faster for SM and FM compared with other conditions (p ≤ 0.05); moreover, there was a high probability of improving running performance when music was applied (SM: 89%; FM: 85%; PM: 39%). Finally, music was capable of accelerating vagal tonus after 5 km of running with CS (p ≤ 0.05). In conclusion, music was able to activate the PFC area, minimize perceptions, improve performance, and accelerate recovery during 5 km of running.

  18. Ion chromatographic determination of anions collected on filters at altitudes between 9.6 and 13.7 kilometers

    NASA Technical Reports Server (NTRS)

    Otterson, D. A.

    1977-01-01

    The investigation of atmospheric pollution to determine the anion-containing particulates in the atmosphere at altitudes between 9.6 and 13.7 km is discussed. Air samples collected on cellulose fiber discs impregnated with dibutoxyethylphthalate require very sensitive methods of analysis. It is concluded that ion chromatography is suited for the determination of anions collected on the filters. Methods to control contamination and interfering side reactions are described.

  19. Atmospheric Effects of the Total Solar Eclipse of 4 December 2002 Simulated with a High-Altitude Global Model

    DTIC Science & Technology

    2007-07-25

    temperature decreases and associated meridional wind changes in the lower mesosphere during eclipses [Ballard et al., 1969; Quiroz and Henry, 1973...atmosphere have reported temperature decreases in the 5–12 K range at 50–60 km altitude during eclipse passages [Ballard et al., 1969; Quiroz and...Henry, 1973; Randhawa, 1974; Schmidlin and Olsen, 1984]. Quiroz and Henry [1973] and Schmidlin and Olsen [1984] also reported substantial increases in

  20. Altitude Testing of Large Liquid Propellant Engines

    NASA Technical Reports Server (NTRS)

    Maynard, Bryon T.; Raines, Nickey G.

    2010-01-01

    The National Aeronautics and Space Administration entered a new age on January 14, 2004 with President Bush s announcement of the creation the Vision for Space Exploration that will take mankind back to the Moon and on beyond to Mars. In January, 2006, after two years of hard, dedicated labor, engineers within NASA and its contractor workforce decided that the J2X rocket, based on the heritage of the Apollo J2 engine, would be the new engine for the NASA Constellation Ares upper stage vehicle. This engine and vehicle combination would provide assured access to the International Space Station to replace that role played by the Space Shuttle and additionally, would serve as the Earth Departure Stage, to push the Crew Excursion Vehicle out of Earth Orbit and head it on a path for rendezvous with the Moon. Test as you fly, fly as you test was chosen to be the guiding philosophy and a pre-requisite for the engine design, development, test and evaluation program. An exhaustive survey of national test facility assets proved the required capability to test the J2X engine at high altitude for long durations did not exist so therefore, a high altitude/near space environment testing capability would have to be developed. After several agency concepts the A3 High Altitude Testing Facility proposal was selected by the J2X engine program on March 2, 2007 and later confirmed by a broad panel of NASA senior leadership in May 2007. This facility is to be built at NASA s John C. Stennis Space Center located near Gulfport, Mississippi. 30 plus years of Space Shuttle Main Engine development and flight certification testing makes Stennis uniquely suited to support the Vision For Space Exploration Return to the Moon. Propellant handling infrastructure, engine assembly facilities, a trained and dedicated workforce and a broad and varied technical support base will all ensure that the A3 facility will be built on time to support the schedule needs of the J2X engine and the ultimate flight