The NASA program on upper atmospheric research

NASA Technical Reports Server (NTRS)

1976-01-01

The purpose of the NASA Upper Atmospheric Research Program is to develop a better understanding of the physical and chemical processes that occur in the earth's upper atmosphere with emphasis on the stratosphere.

Characterization of a 16-Bit Digitizer for Lidar Data Acquisition

NASA Technical Reports Server (NTRS)

Williamson, Cynthia K.; DeYoung, Russell J.

2000-01-01

A 6-MHz 16-bit waveform digitizer was evaluated for use in atmospheric differential absorption lidar (DIAL) measurements of ozone. The digitizer noise characteristics were evaluated, and actual ozone DIAL atmospheric returns were digitized. This digitizer could replace computer-automated measurement and control (CAMAC)-based commercial digitizers and improve voltage accuracy.

Indicators of climate change for the African continent derived from radiosondes

NASA Astrophysics Data System (ADS)

Añel, J. A.; Gimeno, L.; Tesouro, M.; de La Torre, L.; Nieto, R.; Ribera, P.; García, R.; Hernández, E.

2003-04-01

Here we study the interannual variability of different parameters calculated from radiosonde data in the African continent. Data used in the analysis were a subset of the National Climatic Data Center Upper Air Digital Files of the National Oceanic and Atmospheric Administration (USA) (CARDS). This work show the climatic trends in the studied region during the period and from 1973 to 1998). Results show that radiosonde stations were useful for this analysis in the African continent. Main oscillations and the relationship with the Northern Annular Mode and El Niño-Southern Oscillation were also studied.

Numerical study of heating the upper atmosphere by acoustic-gravity waves from a local source on the Earth's surface and influence of this heating on the wave propagation conditions

NASA Astrophysics Data System (ADS)

Karpov, I. V.; Kshevetskii, S. P.

2017-11-01

The propagation of acoustic-gravity waves (AGW) from a source on the Earth's surface to the upper atmosphere is investigated with methods of mathematical modeling. The applied non-linear model of wave propagation in the atmosphere is based on numerical integration of a complete set of two-dimensional hydrodynamic equations. The source on the Earth's surface generates waves with frequencies near to the Brunt-Vaisala frequency. The results of simulation have revealed that some region of heating the atmosphere by propagated upward and dissipated AGWs arises above the source at altitudes nearby of 200 km. The horizontal scale of this heated region is about 1000 km in the case of the source that radiates AGWs during approximately 1 h. The appearing of the heated region has changed the conditions of AGW propagation in the atmosphere. When the heated region in the upper atmosphere has been formed, further a waveguide regime of propagation of waves with the periods shorter the Brunt-Vaisala period is realized. The upper boundary of the wave-guide coincides with the arisen heated region in the upper atmosphere. The considered mechanism of formation of large-scale disturbances in the upper atmosphere may be useful for explanation of connections of processes in the upper and lower atmospheric layers.

The great American solar eclipse of August 21, 2017; new understanding of the response of the upper atmosphere and ionosphere.

NASA Astrophysics Data System (ADS)

Drob, D. P.; Huba, J.; Kordella, L.; Earle, G. D.; Ridley, A. J.

2017-12-01

The great American solar eclipse of August 21, 2017 provides a unique opportunity to study the basic physics of the upper atmosphere and ionosphere. While the effects of solar eclipses on the upper atmosphere and ionosphere have been studied since the 1930s, and later matured in the last several decades, recent advances in first principles numerical models and multi-instrument observational capabilities continue to provide new insights. Upper atmospheric eclipse phenomena such as ionospheric conjugate effects and the generation of a thermospheric bow wave that propagates into the nightside are simulated with high-resolution first principles upper atmospheric models and compared with observations to validate this understanding.

Treading Old Paths in New Ways: Upper Secondary Students Using a Digital Tool of the Professional Historian

ERIC Educational Resources Information Center

Nygren, Thomas; Vikström, Lotta

2013-01-01

This article presents problems and possibilities associated with incorporating into history teaching a digital demographic database made for professional historians. We detect and discuss the outcome of how students in Swedish upper secondary schools respond to a teaching approach involving digitized registers comprising 19th century individuals…

Trajectory Software With Upper Atmosphere Model

NASA Technical Reports Server (NTRS)

Barrett, Charles

2012-01-01

The Trajectory Software Applications 6.0 for the Dec Alpha platform has an implementation of the Jacchia-Lineberry Upper Atmosphere Density Model used in the Mission Control Center for International Space Station support. Previous trajectory software required an upper atmosphere to support atmosphere drag calculations in the Mission Control Center. The Functional operation will differ depending on the end-use of the module. In general, the calling routine will use function-calling arguments to specify input to the processor. The atmosphere model will then compute and return atmospheric density at the time of interest.

Parameterizing Gravity Waves and Understanding Their Impacts on Venus' Upper Atmosphere

NASA Technical Reports Server (NTRS)

Brecht, A. S.; Bougher, S. W.; Yigit, Erdal

2018-01-01

The complexity of Venus’ upper atmospheric circulation is still being investigated. Simulations of Venus’ upper atmosphere largely depend on the utility of Rayleigh Friction (RF) as a driver and necessary process to reproduce observations (i.e. temperature, density, nightglow emission). Currently, there are additional observations which provide more constraints to help characterize the driver(s) of the circulation. This work will largely focus on the impact parameterized gravity waves have on Venus’ upper atmosphere circulation within a three dimensional hydrodynamic model (Venus Thermospheric General Circulation Model).

Ada (Trade Name)/SQL (Structured Query Language) Binding Specification

DTIC Science & Technology

1988-06-01

TYPES iS package ADA-SOL Is type DWPLOYEEyNAME Is new STRING ( 1 .. 30 ); type BOSSNAME is new EMPLOYEENAME; type EMPLOYEE SALARY is digits 7 range 0.00...minimum number of significant decimal digits . All real numbers between the lower and upper bounds, inclusive, belong to the subtype, and are...and the elements of strings. Format <character> -:- < digit > I <letter> ! <special character> < digit > ::- 0111213141516171819 <letter> ::- <upper case

Upper atmosphere has cooled steadily for three decades

NASA Astrophysics Data System (ADS)

Wendel, JoAnna

2014-11-01

Increasing amounts of greenhouse gases released by human activities do not just affect only the lower atmosphere: Scientists project that anthropogenic carbon emissions have caused a cooling trend in the upper atmosphere, between 200 and 400 kilometers, over the past few decades. Cooling in this atmospheric region can affect the operations of satellites and the orbits of space junk. However, data about cooling trends in the upper atmosphere are still incomplete, and better data are needed to confirm this projection.

Climate and atmospheric modeling studies. Climate applications of Earth and planetary observations. Chemistry of Earth and environment

NASA Technical Reports Server (NTRS)

1990-01-01

The research conducted during the past year in the climate and atmospheric modeling programs concentrated on the development of appropriate atmospheric and upper ocean models, and preliminary applications of these models. Principal models are a one-dimensional radiative-convective model, a three-dimensional global climate model, and an upper ocean model. Principal applications have been the study of the impact of CO2, aerosols and the solar 'constant' on climate. Progress was made in the 3-D model development towards physically realistic treatment of these processes. In particular, a map of soil classifications on 1 degree x 1 degree resolution has been digitized, and soil properties have been assigned to each soil type. Using this information about soil properties, a method was developed to simulate the hydraulic behavior of soils of the world. This improved treatment of soil hydrology, together with the seasonally varying vegetation cover, will provide a more realistic study of the role of the terrestrial biota in climate change. A new version of the climate model was created which follows the isotopes of water and sources of water (or colored water) throughout the planet. Each isotope or colored water source is a fraction of the climate model's water. It participates in condensation and surface evaporation at different fractionation rates and is transported by the dynamics. A major benefit of this project has been to improve the programming techniques and physical simulation of the water vapor budget of the climate model.

The UARS (Upper Atmosphere Research Satellite): A program to study global ozone change

NASA Technical Reports Server (NTRS)

1989-01-01

NASA's Upper Atmosphere Research Satellite (UARS) program, its goals and objectives are described. Also included are its significance to upper atmosphere science, the experimental and theoretical investigations that comprise it, and the compelling issues of global change, driven by human activities, that led NASA to plan and implement it.

Marshall Space Flight Center Digital Manufacturing

NASA Technical Reports Server (NTRS)

Arays, Edward; Phillips, Steven

2008-01-01

This presentation highlights the history of DELMIA at MSFC; provides an overview of the Constellation Program; examines the manufacturing of Ares 1 Upper Stage; explains the digital manufacturing implementation for Ares 1 Upper Stage; and, discusses manufacturing and development problems and challenges.

NASA's Upper Atmosphere Research Program (UARP) and Atmospheric Chemistry Modeling and Analysis Program (ACMAP): Research Summaries 1997-1999

NASA Technical Reports Server (NTRS)

Kurylo, M. J.; DeCola, P. L.; Kaye, J. A.

2000-01-01

Under the mandate contained in the FY 1976 NASA Authorization Act, the National Aeronautics and Space Administration (NASA) has developed and is implementing a comprehensive program of research, technology development, and monitoring of the Earth's upper atmosphere, with emphasis on the upper troposphere and stratosphere. This program aims at expanding our chemical and physical understanding to permit both the quantitative analysis of current perturbations as well as the assessment of possible future changes in this important region of our environment. It is carried out jointly by the Upper Atmosphere Research Program (UARP) and the Atmospheric Chemistry Modeling and Analysis Program (ACMAP), both managed within the Research Division in the Office of Earth Science at NASA. Significant contributions to this effort have also been provided by the Atmospheric Effects of Aviation Project (AEAP) of NASA's Office of Aero-Space Technology. The long-term objectives of the present program are to perform research to: understand the physics, chemistry, and transport processes of the upper troposphere and the stratosphere and their control on the distribution of atmospheric chemical species such as ozone; assess possible perturbations to the composition of the atmosphere caused by human activities and natural phenomena (with a specific emphasis on trace gas geographical distributions, sources, and sinks and the role of trace gases in defining the chemical composition of the upper atmosphere); understand the processes affecting the distributions of radiatively active species in the atmosphere, and the importance of chemical-radiative-dynamical feedbacks on the meteorology and climatology of the stratosphere and troposphere; and understand ozone production, loss, and recovery in an atmosphere with increasing abundances of greenhouse gases. The current report is composed of two parts. Part 1 summarizes the objectives, status, and accomplishments of the research tasks supported under NASA UARP and ACMAP in a document entitled, Research Summaries 1997- 1999. Part 2 is entitled Present State of Knowledge of the Upper Atmosphere 1999 An Assessment Report.

Microbial Isolates from the Upper Atmosphere Support Panspermia Hypothesis

NASA Astrophysics Data System (ADS)

Yang, Yinjie; Yokobori, Shin-Ichi; Yamagishi, Akihiko

Terrestrial microbes may be transported into the upper atmosphere via various means. Due to the environmental similarity of the upper atmosphere to outer space, knowledge of microbes in the upper atmosphere would be valuable for assessing the chances and limits of microbial transfer from the earth to extraterrestrial bodies (i.e., Panspermia of terrestrial microbes). We collected air dust samples in the upper troposphere and the stratosphere over Japan by using aircrafts or balloons. Microbial isolates from the samples were endospore-forming species (Bacillus, Paenibacillus, Streptomyces) and non-spore-forming Deinococci. Besides the evidence of microbial presence in the upper atmosphere, we show the possible presence of terrestrial microbes in space by extrapolated height-dependent distribution of microbes. High resistance to radiation and desiccation was common for our upper-atmospheric isolates and likely the most important feature enabled their survival in the environment of elevated radiation and desiccation. In this regard, Panspermia of viable Deinococci and endospores would be more likely than other terrestrial microbes. Specifically, the Deinococcus isolates exhibited extreme resistance to radiation (several times higher than bacterial endospores), the principle threat for microbial survival during interplanetary transfer. Based on detailed characterization of the Deinococcus isolates, we proposed two new species Deinococcus aerius sp. nov. and Deinococcus aetherius sp. nov., which are now candidate microbes for exposure experiment in space.

Observation and Modeling of Tsunami-Generated Gravity Waves in the Earth’s Upper Atmosphere

DTIC Science & Technology

2015-10-08

Observation and modeling of tsunami -generated gravity waves in the earth’s upper atmosphere 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6...ABSTRACT Build a compatible set of models which 1) calculate the spectrum of atmospheric GWs excited by a tsunami (using ocean model data as input...for public release; distribution is unlimited. Observation and modeling of tsunami -generated gravity waves in the earth’s upper atmosphere Sharon

The thermal structure and energy balance of the Uranian upper atmosphere

NASA Technical Reports Server (NTRS)

French, R. G.; Dunham, E. W.; Allen, D. A.; Elias, J. H.; Frogel, J. A.; Elliot, J. L.; Liller, W.

1983-01-01

Uranus upper atmosphere occultation observations are reported for August 15-16, 1980, and April 26, 1981. Mean atmospheric light curves of 154 + or - 15 K and 132 + or - 15 K, respectively, are derived from the light curves. A comparison of all available Uranus occultation data since March 1977 suggests a significant mean atmospheric temperature change, with a typical 15 K/year variation. It is suggested that molecular and eddy diffusion, together with atmospheric dynamics, are potentially as important as radiation in the upper atmosphere heat balance of Uranus. The close agreement of occultation immersion and emersion temperatures further suggests that effective meridional transport occurs on Uranus.

A review of supernumerary and absent limbs and digits of the upper limb.

PubMed

Klaassen, Zachary; Choi, Monica; Musselman, Ruth; Eapen, Deborah; Tubbs, R Shane; Loukas, Marios

2012-03-01

For years people have been enamored by anomalies of the human limbs, particularly supernumerary and absent limbs and digits. Historically, there are a number of examples of such anomalies, including royal families of ancient Chaldea, tribes from Arabia, and examples from across nineteenth century Europe. The development of the upper limbs in a growing embryo is still being elucidated with the recent advent of homeobox genes, but researchers agree that upper limbs develop between stages 12-23 through a complex embryological process. Maternal thalidomide intake during limb development is known to cause limb reduction and subsequent amelia or phocomelia. Additionally, a number of clinical reports have illustrated different limb anomaly cases, with each situation unique in phenotype and developmental abnormality. Supernumerary and absent limbs and digits are not unique to humans, and a number of animal cases have also been reported. This review of the literature illustrates the historical, anatomical, and clinical aspects of supernumerary and absent limbs and digits for the upper limb.

Upper atmosphere pollution measurements (GASP)

NASA Technical Reports Server (NTRS)

Rudey, R. A.; Holdeman, J. D.

1975-01-01

The environmental effects are discussed of engine effluents of future large fleets of aircraft operating in the stratosphere. Topics discussed include: atmospheric properties, aircraft engine effluents, upper atmospheric measurements, global air sampling, and data reduction and analysis

Studies in upper and lower atmosphere coupling

NASA Technical Reports Server (NTRS)

Chiu, Y. T.; Rice, C. J.; Sharp, L. R.

1979-01-01

The theoretical and data-analytic work on upper and lower atmosphere coupling performed under a NASA Headquarters contract during the period April 1978 to March 1979 are summarized. As such, this report is primarily devoted to an overview of various studies published and to be published under this contract. Individual study reports are collected as exhibits. Work performed under the subject contract are in the following four areas of upper-lower atmosphere coupling: (1) Magnetosphere-ionosphere electrodynamic coupling in the aurora; (2) Troposphere-thermosphere coupling; (3) Ionosphere-neutral-atmosphere coupling; and (4) Planetary wave dynamics in the middle atmosphere.

Ion neutral mass spectrometer results from the first flyby of Titan.

PubMed

Waite, J Hunter; Niemann, Hasso; Yelle, Roger V; Kasprzak, Wayne T; Cravens, Thomas E; Luhmann, Janet G; McNutt, Ralph L; Ip, Wing-Huen; Gell, David; De La Haye, Virginie; Müller-Wordag, Ingo; Magee, Brian; Borggren, Nathan; Ledvina, Steve; Fletcher, Greg; Walter, Erin; Miller, Ryan; Scherer, Stefan; Thorpe, Rob; Xu, Jing; Block, Bruce; Arnett, Ken

2005-05-13

The Cassini Ion Neutral Mass Spectrometer (INMS) has obtained the first in situ composition measurements of the neutral densities of molecular nitrogen, methane, molecular hydrogen, argon, and a host of stable carbon-nitrile compounds in Titan's upper atmosphere. INMS in situ mass spectrometry has also provided evidence for atmospheric waves in the upper atmosphere and the first direct measurements of isotopes of nitrogen, carbon, and argon, which reveal interesting clues about the evolution of the atmosphere. The bulk composition and thermal structure of the moon's upper atmosphere do not appear to have changed considerably since the Voyager 1 flyby.

Cosmic Radiation Detection and Observations

NASA Astrophysics Data System (ADS)

Ramirez Chavez, Juan; Troncoso, Maria

Cosmic rays consist of high-energy particles accelerated from remote supernova remnant explosions and travel vast distances throughout the universe. Upon arriving at earth, the majority of these particles ionize gases in the upper atmosphere, while others interact with gas molecules in the troposphere and producing secondary cosmic rays, which are the main focus of this research. To observe these secondary cosmic rays, a detector telescope was designed and equipped with two silicon photomultipliers (SiPMs). Each SiPM is coupled to a bundle of 4 wavelength shifting optical fibers that are embedded inside a plastic scintillator sheet. The SiPM signals were amplified using a fast preamplifier with coincidence between detectors established using a binary logic gate. The coincidence events were recorded with two devices; a digital counter and an Arduino micro-controller. For detailed analysis of the SiPM waveforms, a DRS4 sensory digitizer captured the waveforms for offline analysis with the CERN software package Physics Analysis Workstation in a Linux environment. Results from our experiments would be presented. Hartnell College STEM Internship Program.

Digital Game-Based Learning to Encourage Secondary Students to Purse STEM Related Careers Using Arecibo Observatory

NASA Astrophysics Data System (ADS)

Ortiz-Correa, Z. M.; Lautenbach, J.; Franco-Diaz, E.; Raizada, S.; Ghosh, T.; Rivera-Valentín, E.; Ortiz, A.

2017-12-01

This project was developed to encourage secondary students to pursue STEM related careers through exposure to the interdisciplinary nature of the Arecibo Observatory (AO) in Puerto Rico. The idea for this project was initiated due to the NSF-funded Research Experience for Teachers (RET) Summer Program. The AO RET summer program allows teaching faculty from public schools to collaborate with scientist on their ongoing research or instrument development projects at the AO for five weeks. Subsequently, the research is disseminated among secondary students through several workshops and hands-on activities. Through the workshops and hands-on activities underrepresented secondary students will learn about the research conducted at the AO to study Earth's upper atmosphere, asteroids and other Solar System bodies, as well as stars and galaxies beyond. Afterwards, students will develop virtual worlds simulating the different AO facilities (Lidar Laboratory, Radio Telescope, Planetary Radar System, HF Facility, Visitor Center, among others) and showing their functions using digital game-based learning.

Seeing Earth Through the Eyes of an Astronaut

NASA Technical Reports Server (NTRS)

Dawson, Melissa

2014-01-01

The Human Exploration Science Office within the ARES Directorate has undertaken a new class of handheld camera photographic observations of the Earth as seen from the International Space Station (ISS). For years, astronauts have attempted to describe their experience in space and how they see the Earth roll by below their spacecraft. Thousands of crew photographs have documented natural features as diverse as the dramatic clay colors of the African coastline, the deep blues of the Earth's oceans, or the swirling Aurora Borealis of Australia in the upper atmosphere. Dramatic recent improvements in handheld digital single-lens reflex (DSLR) camera capabilities are now allowing a new field of crew photography: night time-lapse imagery.

Acoustic explorations of the upper ocean boundary layer

NASA Astrophysics Data System (ADS)

Vagle, Svein

2005-04-01

The upper ocean boundary layer is an important but difficult to probe part of the ocean. A better understanding of small scale processes at the air-sea interface, including the vertical transfer of gases, heat, mass and momentum, are crucial to improving our understanding of the coupling between atmosphere and ocean. Also, this part of the ocean contains a significant part of the total biomass at all trophic levels and is therefore of great interest to researchers in a range of different fields. Innovative measurement plays a critical role in developing our understanding of the processes involved in the boundary layer, and the availability of low-cost, compact, digital signal processors and sonar technology in self-contained and cabled configurations has led to a number of exciting developments. This talk summarizes some recent explorations of this dynamic boundary layer using both active and passive acoustics. The resonant behavior of upper ocean bubbles combined with single and multi-frequency broad band active and passive devices are now giving us invaluable information on air-sea gas transfer, estimation of biological production, marine mammal behavior, wind speed and precipitation, surface and internal waves, turbulence, and acoustic communication in the surf zone.

Modelling of plasma processes in cometary and planetary atmospheres

NASA Astrophysics Data System (ADS)

Campbell, L.; Brunger, M. J.

2013-02-01

Electrons from the Sun, often accelerated by magnetospheric processes, produce low-density plasmas in the upper atmospheres of planets and their satellites. The secondary electrons can produce further ionization, dissociation and excitation, leading to enhancement of chemical reactions and light emission. Similar processes are driven by photoelectrons produced by sunlight in upper atmospheres during daytime. Sunlight and solar electrons drive the same processes in the atmospheres of comets. Thus for both understanding of planetary atmospheres and in predicting emissions for comparison with remote observations it is necessary to simulate the processes that produce upper atmosphere plasmas. In this review, we describe relevant models and their applications and address the importance of electron-impact excitation cross sections, towards gaining a quantitative understanding of the phenomena in question.

Impacts of space weather events on the structure of the upper atmosphere

NASA Astrophysics Data System (ADS)

Lee, Y.; Mahaffy, P. R.; Benna, M.; Elrod, M. K.

2017-12-01

Due to the absence of the intrinsic magnetic field, Mars' upper atmosphere is vulnerable to the solar wind, which directly strips away the Martian upper atmosphere via various mechanisms, resulting in interesting global phenomena that are observable. The Mars Atmosphere and Volatile EvolutioN (MAVEN) has observed the responses of the upper atmosphere such as Interplanetary Coronal Mass Ejections (ICMEs) and Solar flare events spanning from November 2014 to the present. A comprehensive set of observations taken by the MAVEN instrument package enables the better characterization of the thermospheric and ionospheric behavior affected by various space weather events. The observed impacts include changes in the upper atmospheric and ionospheric density and temperature, enhancements of atmospheric loss rate of ions and neutrals, and changes in important boundary layers. The measurements by plasma and field instruments allows the upstream monitoring of the solar EUV, solar energetic particles, and Interplanetary Magnetic Field (IMF) simultaneously and provide additional information of the near-Mars space weather disturbances. In addition, at low altitudes near the periapsis of the spacecraft, the simultaneous measurements of the magnetic field and properties of the thermosphere and ionosphere allow the analysis of the effects of the local crustal magnetic fields. Here, adding to the reported MAVEN observations of the space weather impacts at Mars, we analyze the responses of the upper atmosphere to the mars-impacting space weather events observed by MAVEN. We focus mainly on the responses of the density and temperature structures, which in turn allow us to examine the effects on the important atmospheric layers such as the M2 layer and transition region from the thermosphere to exosphere.

Space fireworks for upper atmospheric wind measurements by sounding rocket experiments

NASA Astrophysics Data System (ADS)

Yamamoto, M.

2016-01-01

Artificial meteor trains generated by chemical releases by using sounding rockets flown in upper atmosphere were successfully observed by multiple sites on ground and from an aircraft. We have started the rocket experiment campaign since 2007 and call it "Space fireworks" as it illuminates resonance scattering light from the released gas under sunlit/moonlit condition. By using this method, we have acquired a new technique to derive upper atmospheric wind profiles in twilight condition as well as in moonlit night and even in daytime. Magnificent artificial meteor train images with the surrounding physics and dynamics in the upper atmosphere where the meteors usually appear will be introduced by using fruitful results by the "Space firework" sounding rocket experiments in this decade.

Preliminary design study of a high resolution meteor radar

NASA Technical Reports Server (NTRS)

Lee, W.; Geller, M. A.

1973-01-01

A design study for a high resolution meteor radar system is carried out with the objective of measuring upper atmospheric winds and particularly studying short period atmospheric waves in the 80 to 120 km altitude region. The transmitter that is to be used emits a peak power of 4 Mw. The system is designed to measure the wind velocity and height of a meteor trail very accurately. This is achieved using a specially developed digital reduction procedure to determine wind velocity and range together with an interferometer for measuring both the azimuth and elevation angles of the region with a long baseline vernier measurement being used to refine the elevation angle measurement. The resultant accuracies are calculated to be + or - 0.9 m/s for the wind, + or - 230 m for the range and + or - 0.12 deg for the elevation angle, giving a height accuracy of + or - 375 m. The prospects for further development of this system are also discussed.

Upper Atmospheric Response to the April 2010 Storm as Observed by GOCE, CHAMP, and GRACE and Modeled by TIME-GCM

NASA Astrophysics Data System (ADS)

Hagan, Maura; Häusler, Kathrin; Lu, Gang; Forbes, Jeffrey; Zhang, Xiaoli; Doornbos, Eelco; Bruinsma, Sean

2014-05-01

We present the results of an investigation of the upper atmosphere during April 2010 when it was disturbed by a fast-moving coronal mass ejection. Our study is based on comparative analysis of observations made by the Gravity field and steady-state Ocean Circulation Explorer (GOCE), Challenging Minisatellite Payload (CHAMP), and Gravity Recovery And Climate Experiment (GRACE) satellites and a set of simulations with the National Center for Atmospheric Research (NCAR) thermosphere-ionosphere-mesosphere-electrodynamics general circulation model (TIME-GCM). We compare and contrast the satellite observations with TIME-GCM results from a realistic simulation based on prevailing meteorological and solar geomagnetic conditions. We diagnose the comparative importance of the upper atmospheric signatures attributable to meteorological forcing with those attributable to storm effects by diagnosing a series of complementary control TIME-GCM simulations. These results also quantify the extent to which lower and middle atmospheric sources of upper atmospheric variability precondition its response to the solar geomagnetic storm.

NASA's upper atmosphere research satellite: A program to study global ozone change

NASA Technical Reports Server (NTRS)

Luther, Michael R.

1992-01-01

The Upper Atmosphere Research Satellite (UARS) is a major initiative in the NASA Office of Space Science and Applications, and is the prototype for NASA's Earth Observing System (EOS) planned for launch in the 1990s. The UARS combines a balanced program of experimental and theoretical investigations to perform diagnostic studies, qualitative model analysis, and quantitative measurements and comparative studies of the upper atmosphere. UARS provides theoretical and experimental investigations which pursue four specific research topics: atmospheric energy budget, chemistry, dynamics, and coupling processes. An international cadre of investigators was assembled by NASA to accomplish those scientific objectives. The observatory, its complement of ten state of the art instruments, and the ground system are nearing flight readiness. The timely UARS program will play a major role in providing data to understand the complex physical and chemical processes occurring in the upper atmosphere and answering many questions regarding the health of the ozone layer.

Maui Analysis of Upper Atmospheric Injections

NASA Technical Reports Server (NTRS)

Dressler, Rainer A.

2008-01-01

Maui Analysis of Upper Atmospheric Injections (MAUI) will observe the Space Shuttle engine exhaust plumes from the Maui Space Surveillance Site in Hawaii. The observations will occur when the Space Shuttle fires its engines at night or twilight. A telescope and all-sky imagers will take images and data while the Space Shuttle flies over the Maui site. The images will be analyzed to better understand the interaction between the spacecraft plume and the upper atmosphere of Earth.

Rocket Ozone Data Recovery for Digital Archival

NASA Astrophysics Data System (ADS)

Hwang, S. H.; Krueger, A. J.; Hilsenrath, E.; Haffner, D. P.; Bhartia, P. K.

2014-12-01

Ozone distributions in the photochemically-controlled upper stratosphere and mesosphere were first measured using spectrometers on V-2 rockets after WWII. The IGY(1957-1958) spurred development of new optical and chemical instruments for flight on meteorological and sounding rockets. In the early 1960's, the US Navy developed an Arcas rocket-borne optical ozonesonde and NASA GSFC developed chemiluminescent ozonesonde onboard Nike_Cajun and Arcas rocket. The Navy optical ozone program was moved in 1969 to GSFC where rocket ozone research was expanded and continued until 1994 using Super Loki-Dart rocket at 11 sites in the range of 0-65N and 35W-160W. Over 300 optical ozone soundings and 40 chemiluminescent soundings were made. The data have been used to produce the US Standard Ozone Atmosphere, determine seasonal and diurnal variations, and validate early photochemical models. The current effort includes soundings conducted by Australia, Japan, and Korea using optical techniques. New satellite ozone sounding techniques were initially calibrated and later validated using the rocket ozone data. As satellite techniques superseded the rocket methods, the sponsoring agencies lost interest in the data and many of those records have been discarded. The current task intends to recover as much of the data as possible from the private records of the experimenters and their publications, and to archive those records in the WOUDC (World Ozone and Ultraviolet Data Centre). The original data records are handwritten tabulations, computer printouts that are scanned with OCR techniques, and plots digitized from publications. This newly recovered digital rocket ozone profile data from 1965 to 2002 could make significant contributions to the Earth science community in atmospheric research including long-term trend analysis.

SUMS preliminary design and data analysis development. [shuttle upper atmosphere mass spectrometer experiment

NASA Technical Reports Server (NTRS)

Hinson, E. W.

1981-01-01

The preliminary analysis and data analysis system development for the shuttle upper atmosphere mass spectrometer (SUMS) experiment are discussed. The SUMS experiment is designed to provide free stream atmospheric density, pressure, temperature, and mean molecular weight for the high altitude, high Mach number region.

A comparative study of Venus and Mars - Upper atmospheres, ionospheres and solar wind interactions

NASA Technical Reports Server (NTRS)

Mahajan, K. K.; Kar, J.

1990-01-01

The neutral atmospheres of Mars and Venus are discussed. A comparative study is presented of the upper atmospheres, ionospheres, and solar wind interactions of these two planets. The review is mainly concerned with the region about 100 km above the surface of the planets.

Digital Competence at the Beginning of Upper Secondary School: Identifying Factors Explaining Digital Inclusion

ERIC Educational Resources Information Center

Hatlevik, Ove Edvard; Christophersen, Knut-Andreas

2013-01-01

During the last decade, information and communication technology has been given an increasingly large importance in our society. There seems to be a consensus regarding the necessity of supporting and developing school-based digital competence. In order to sustain digital inclusion, schools need to identify digital deficiencies and digital…

Modeling the Influences of Upper-Elementary School Students' Digital Reading Literacy, Socioeconomic Factors, and Self-Regulated Learning Strategies

ERIC Educational Resources Information Center

Chen, Shin-Feng

2017-01-01

Background: Reading is an interactive and constructive process of making meaning by engaging a variety of materials and sources and by participating in reading communities at school or in daily life. Aim: The purpose of this study was to explore the factors affecting digital reading literacy among upper-elementary school students. Method: A…

A quasi-static model of global atmospheric electricity. II - Electrical coupling between the upper and lower atmosphere

NASA Technical Reports Server (NTRS)

Roble, R. G.; Hays, P. B.

1979-01-01

The paper presents a model of global atmospheric electricity used to examine the effect of upper atmospheric generators on the global electrical circuit. The model represents thunderstorms as dipole current generators randomly distributed in areas of known thunderstorm frequency; the electrical conductivity in the model increases with altitude, and electrical effects are coupled with a passive magnetosphere along geomagnetic field lines. The large horizontal-scale potential differences at ionospheric heights map downward into the lower atmosphere where the perturbations in the ground electric field are superimposed on the diurnal variation. Finally, changes in the upper atmospheric conductivity due to solar flares, polar cap absorptions, and Forbush decreases are shown to alter the downward mapping of the high-latitude potential pattern and the global distribution of fields and currents.

Effectiveness of three-dimensional digital animation in teaching human anatomy in an authentic classroom context.

PubMed

Hoyek, Nady; Collet, Christian; Di Rienzo, Franck; De Almeida, Mickael; Guillot, Aymeric

2014-01-01

Three-dimensional (3D) digital animations were used to teach the human musculoskeletal system to first year kinesiology students. The purpose of this study was to assess the effectiveness of this method by comparing two groups from two different academic years during two of their official required anatomy examinations (trunk and upper limb assessments). During the upper limb section, the teacher used two-dimensional (2D) drawings embedded into PowerPoint(®) slides and 3D digital animations for the first group (2D group) and the second (3D group), respectively. The same 3D digital animations were used for both groups during the trunk section. The only difference between the two was the multimedia used to present the information during the upper limb section. The 2D group surprisingly outperformed the 3D group on the trunk assessment. On the upper limb assessment no difference in the scores on the overall anatomy examination was found. However, the 3D group outperformed the 2D group in questions requiring spatial ability. Data supported that 3D digital animations were effective instructional multimedia material tools in teaching human anatomy especially in recalling anatomical knowledge requiring spatial ability. The importance of evaluating the effectiveness of a new instructional material outside laboratory environment (e.g., after a complete semester and on official examinations) was discussed. © 2014 American Association of Anatomists.

Studies of planetary upper atmospheres through occultations

NASA Technical Reports Server (NTRS)

Elliot, J. L.

1982-01-01

The structure, composition, dynamics and energy balance of planetary upper atmospheres through interpretation of steller occultation data from Uranus is discussed. The wave-optical problem of modelling strong scintillation for arbitrary turbulent atmospheres is studied, as well as influence of turbulence. It was concluded that quasi-global features of atmospheric structure are accurately determined by numerical inversion. Horizontally inhomogeneous structures are filtered out and have little effect on temperature profiles.

The solar-terrestrial environment. An introduction to geospace - the science of the terrestrial upper atmosphere, ionosphere and magnetosphere.

NASA Astrophysics Data System (ADS)

Hargreaves, J. K.

This textbook is a successor to "The upper atmosphere and solar-terrestrial relations" first published in 1979. It describes physical conditions in the upper atmosphere and magnetosphere of the Earth. This geospace environment begins 70 kilometres above the surface of the Earth and extends in near space to many times the Earth's radius. It is the region of near-Earth environment where the Space Shuttle flies, the aurora is generated, and the outer atmosphere meets particles streaming out of the sun. The account is introductory. The intent is to present basic concepts, and for that reason the mathematical treatment is not complex. There are three introductory chapters that give basic physics and explain the principles of physical investigation. The principal material contained in the main part of the book covers the neutral and ionized upper atmosphere, the magetosphere, and structures, dynamics, disturbances and irregularities. The concluding chapter deals with technological applications.

Climate and atmospheric modeling studies

NASA Technical Reports Server (NTRS)

1992-01-01

The climate and atmosphere modeling research programs have concentrated on the development of appropriate atmospheric and upper ocean models, and preliminary applications of these models. Principal models are a one-dimensional radiative-convective model, a three-dimensional global model, and an upper ocean model. Principal applications were the study of the impact of CO2, aerosols, and the solar 'constant' on climate.

MAVEN observations of the response of Mars to an interplanetary coronal mass ejection.

PubMed

Jakosky, B M; Grebowsky, J M; Luhmann, J G; Connerney, J; Eparvier, F; Ergun, R; Halekas, J; Larson, D; Mahaffy, P; McFadden, J; Mitchell, D F; Schneider, N; Zurek, R; Bougher, S; Brain, D; Ma, Y J; Mazelle, C; Andersson, L; Andrews, D; Baird, D; Baker, D; Bell, J M; Benna, M; Chaffin, M; Chamberlin, P; Chaufray, Y-Y; Clarke, J; Collinson, G; Combi, M; Crary, F; Cravens, T; Crismani, M; Curry, S; Curtis, D; Deighan, J; Delory, G; Dewey, R; DiBraccio, G; Dong, C; Dong, Y; Dunn, P; Elrod, M; England, S; Eriksson, A; Espley, J; Evans, S; Fang, X; Fillingim, M; Fortier, K; Fowler, C M; Fox, J; Gröller, H; Guzewich, S; Hara, T; Harada, Y; Holsclaw, G; Jain, S K; Jolitz, R; Leblanc, F; Lee, C O; Lee, Y; Lefevre, F; Lillis, R; Livi, R; Lo, D; Mayyasi, M; McClintock, W; McEnulty, T; Modolo, R; Montmessin, F; Morooka, M; Nagy, A; Olsen, K; Peterson, W; Rahmati, A; Ruhunusiri, S; Russell, C T; Sakai, S; Sauvaud, J-A; Seki, K; Steckiewicz, M; Stevens, M; Stewart, A I F; Stiepen, A; Stone, S; Tenishev, V; Thiemann, E; Tolson, R; Toublanc, D; Vogt, M; Weber, T; Withers, P; Woods, T; Yelle, R

2015-11-06

Coupling between the lower and upper atmosphere, combined with loss of gas from the upper atmosphere to space, likely contributed to the thin, cold, dry atmosphere of modern Mars. To help understand ongoing ion loss to space, the Mars Atmosphere and Volatile Evolution (MAVEN) spacecraft made comprehensive measurements of the Mars upper atmosphere, ionosphere, and interactions with the Sun and solar wind during an interplanetary coronal mass ejection impact in March 2015. Responses include changes in the bow shock and magnetosheath, formation of widespread diffuse aurora, and enhancement of pick-up ions. Observations and models both show an enhancement in escape rate of ions to space during the event. Ion loss during solar events early in Mars history may have been a major contributor to the long-term evolution of the Mars atmosphere. Copyright © 2015, American Association for the Advancement of Science.

Composition and structure of the martian upper atmosphere: analysis of results from viking.

PubMed

McElroy, M B; Kong, T Y; Yung, Y L; Nier, A O

1976-12-11

Densities for carbon dioxide measured by the upper atmospheric mass spectrometers on Viking 1 and Viking 2 are analyzed to yield height profiles for the temperature of the martian atmosphere between 120 and 200 kilometers. Densities for nitrogen and argon are used to derive vertical profiles for the eddy diffusion coefficient over the same height range. The upper atmosphere of Mars is surprisingly cold with average temperatures for both Viking 1 and Viking 2 of less than 200 degrees K, and there is significant vertical structure. Model calculations are presented and shown to be in good agreement with measured concentrations of carbon monoxide, oxygen, and nitric oxide.

Investigation of Dynamic and Physical Processes in the Upper Troposphere and Lower Stratosphere

NASA Technical Reports Server (NTRS)

Selkirk, Henry B.; Pfister, Leonhard (Technical Monitor)

2002-01-01

Research under this Cooperative Agreement has been funded by several NASA Earth Science programs: the Atmospheric Effects of Radiation Program (AEAP), the Upper Atmospheric Research Program (UARP), and most recently the Atmospheric Chemistry and Modeling Assessment Program (ACMAP). The purpose of the AEAP was to understand the impact of the present and future fleets of conventional jet traffic on the upper troposphere and lower stratosphere, while complementary airborne observations under UARP seek to understand the complex interactions of dynamical and chemical processes that affect the ozone layer. The ACMAP is a more general program of modeling and data analysis in the general area of atmospheric chemistry and dynamics, and the Radiation Sciences program.

Artist Concept of MAVEN Imaging Ultraviolet Spectrograph at Work

NASA Image and Video Library

2014-11-07

This artist concept depicts the Imaging Ultraviolet Spectrograph IUVS on NASA MAVEN spacecraft scanning the upper atmosphere of Mars. IUVS uses limb scans to map the chemical makeup and vertical structure across Mars upper atmosphere.

Performance analysis for the cryogenic etalon spectrometer on the Upper Atmospheric Research Satellite

NASA Technical Reports Server (NTRS)

Roche, A. E.; Forney, P. B.; Kumer, J. B.; Naes, L. G.; Nast, T. C.

1983-01-01

The Upper Atmospheric Research Satellite (UARS) program has the objective of providing an 18-month to 2-year platform for observations of the upper atmosphere, giving particular attention to the stratosphere, mesosphere, and lower thermosphere. The primary aims of the mission are related to the measurement of the solar energy input between 120 and 500 km, the acquisition of global maps of the vertical and horizontal distribution of a series of critical trace and minor species, and the investigation of the dynamics of the upper atmosphere. One of several instruments designed to perform neutral species measurements on board the satellite is the Cryogenic Limb Array Etalon Spectrometer (CLAES). The CLAES experiment is concerned with measurements of concentrations of species of interest to the ozone layer balance. Attention is given to the performance requirements of the instrument and the effects of these requirements on the cryogenic design.

Superthermal electron processes in the upper atmosphere of Uranus: Aurora and electroglow

NASA Technical Reports Server (NTRS)

Waite, J. H., Jr.; Chandler, M. O.; Yelle, R. V.; Sandel, B. R.

1987-01-01

Strong ultraviolet emissions from the upper atmosphere of Uranus suggest that both auroral and electroglow phenomena are of significant aeronomical consequences in the structure of the upper atmosphere. Combined modeling and data analysis were performed to determine the effect of electroglow and auroral phenomena on the global heat and atomic hydrogen budgets in the Uranus upper atmosphere. The results indicate that the auroral and electroglow heat sources are not adequate to explain the high exospheric temperature observed at Uranus, but that the atomic hydrogen supplied by these processes is more than sufficient to explain the observations. The various superthermal electron distributions modeled have significantly different efficiencies for the various processes such as UV emission, heating, ionization, and atomic hydrogen production, and produce quite different H2 band spectra. However, additional information on the UV spectra and global parameters is needed before modeling can be used to distinguish between the possible mechanisms for electroglow.

Digitisation of Historical Observations for ERA-CLIM

NASA Astrophysics Data System (ADS)

Stickler, A.; Brönnimann, S.; Valente, M. A.; Sterin, A.; Jourdain, S.; Guzman, J.; Allan, R.; Dee, D.

2012-04-01

Aside from improvements in the assimilation and numerical modelling schemes, new reanalyses can significantly profit from the recovery, imaging and digitisation of historical observations. Here, we present the status and selected examples of the digitisation of historical surface, aerological and radiation measurements in the framework of ERA-CLIM, an EU FP7 project designed to prepare the data necessary for a new reanalysis going back to the beginning of the 20th century. One peculiarity of this reanalysis is the fact that it will, for the first time, assimilate upper-air data from the time before 1948. The data rescue activities of ERA-CLIM specifically focus on the data-sparse regions, such as the Tropics, the polar regions and the world's oceans before 1957. From the time before 1957, large amounts of surface data from former colonies and from overseas territories of European countries (e.g. Portugal and France) are being digitised. These surface data make up ca. 55% of the estimated total station days that have been inventorised. Another 45% of the inventorised data consist of upper-air (aerological) observations. A relatively tiny fraction (< 1%) are atmospheric transmission measurements from 13 stations worldwide (1902-50). In case of the very early upper-air observations before the 1930s, even Europe and North America still hold an important quantity of data to be recovered in digital form. The inventory of all identified data sources and their digital imaging have almost been completed. The digitisation is still ongoing and will partly be continued for some time. However, due to the vast amount of records identified and the large amount of data, especially in the case of upper-air (1638 inventory entries, 1.3 mio. station days) and surface data (1.55 mio. station days), a prioritisation in agreement with the goals and deliverables of the project turned out to be necessary. The largest single sources of upper-air data found were the NOAA Central Library Foreign Data section (27%, data from many countries) and Indian upper-air and weather bulletins (27%), followed by many smaller sources, each making up less than 5% of the total amount of data. For the whole project, 16% of the upper-air data inventory entries stem from aircraft, registering balloon, kite or captive balloon measurements, 25% from radiosondes, and the largest part, 60%, are pilot balloon wind observations. Quality control and reformatting of the data have started and will soon be finished so that the first version of the data can be delivered on time in June.

Pluto Haze

NASA Image and Video Library

2015-09-10

Two different versions of an image of Pluto's haze layers, taken by New Horizons as it looked back at Pluto's dark side nearly 16 hours after close approach, from a distance of 480,000 miles (770,000 kilometers), at a phase angle of 166 degrees. Pluto's north is at the top, and the sun illuminates Pluto from the upper right. These images are much higher quality than the digitally compressed images of Pluto's haze downlinked and released shortly after the July 14 encounter, and allow many new details to be seen. The left version has had only minor processing, while the right version has been specially processed to reveal a large number of discrete haze layers in the atmosphere. In the left version, faint surface details on the narrow sunlit crescent are seen through the haze in the upper right of Pluto's disk, and subtle parallel streaks in the haze may be crepuscular rays- shadows cast on the haze by topography such as mountain ranges on Pluto, similar to the rays sometimes seen in the sky after the sun sets behind mountains on Earth. http://photojournal.jpl.nasa.gov/catalog/PIA19880

Semiannual progress report, April - September 1991

NASA Technical Reports Server (NTRS)

1991-01-01

Research conducted during the past year in the climate and modeling programs has concentrated on the development of appropriate atmospheric and upper ocean models, and preliminary applications of these models. Principal models are a one-dimensional radiative-convective model, a three dimensional global climate model, and an upper ocean model. Principal applications have been the study of the impact of CO2, aerosols, and the solar constant on climate. Progress was made in the 3-D model development towards physically realistic treatment of these processes. In particular, a map of soil classifications on 1 degree by 1 degree resolution has now been digitized, and soil properties have been assigned to each soil type. Using this information about soil properties, a method has been developed to simulate the hydraulic behavior of the soils of the world. This improved treatment of soil hydrology, together with the seasonally varying vegetation cover, will provide a more realistic study of the role of the terrestrial biota in climate change. A new version of the climate model was created which follows the isotopes of water and sources of water throughout the planet.

The Earth's Middle Atmosphere: COSPAR Plenary Meeting, 29th, Washington, DC, 28 Aug.-5 Sep., 1992

NASA Technical Reports Server (NTRS)

Grosse, W. L. (Editor); Ghazi, A. (Editor); Geller, M. A. (Editor); Shepherd, G. G. (Editor)

1994-01-01

The conference presented the results from the Upper Atmosphere Research Satellite (UARS) in the areas of wind, temperature, composition, and energy input into the upper atmosphere. Also presented is the current status of validation of the UARS temperature and wind instruments measuring at and above the menopause. The two UARS instruments involved were the High Resolution Doppler Imager (HRDI) and the WIND Imaging Interferometer (WINDII). Papers are presented covering almost all aspects of middle atmospheric science, including dynamics, layering in the middle atmosphere, atmospheric composition, solar and geomagnetic effects, electrodynamics, and the ionosphere.

Space Shuttle Orbiter Digital Outer Mold Line Scanning

NASA Technical Reports Server (NTRS)

Campbell, Charles H.; Wilson, Brad; Pavek, Mike; Berger, Karen

2012-01-01

The Space Shuttle Orbiters Discovery and Endeavor have been digitally scanned to produce post-flight configuration outer mold line surfaces. Very detailed scans of the windward side of these vehicles provide resolution of the detailed tile step and gap geometry, as well as the reinforced carbon carbon nose cap and leading edges. Lower resolution scans of the upper surface provide definition of the crew cabin windows, wing upper surfaces, payload bay doors, orbital maneuvering system pods and the vertical tail. The process for acquisition of these digital scans as well as post-processing of the very large data set will be described.

Wave-mean flow interactions in the upper atmosphere

NASA Technical Reports Server (NTRS)

Lindzen, R. S.

1973-01-01

The nature of internal gravity waves is described with special emphasis on their ability to transport energy and momentum. The conditions under which these fluxes interact with the mean state of the atmosphere are described and the results are applied to various problems of the upper atmosphere, including the quasi-biennial oscillation, the heat budget of the thermosphere, the general circulation of the mesosphere, turbulence in the mesosphere, and the 4-day circulation of the Venusian atmosphere.

Microwave Limb Sounder/El Niño Watch - Water Vapor Measurement, October, 1997

NASA Image and Video Library

1997-10-30

This image shows atmospheric water vapor in Earth upper troposphere, about 10 kilometers 6 miles above the surface, as measured by NASA Microwave Limb Sounder MLS instrument flying aboard the Upper Atmosphere Research Satellite.

Review of spectroscopic parameters for upper atmospheric measurements

NASA Technical Reports Server (NTRS)

Smith, M. A. H. (Editor)

1985-01-01

The workshop included communication of spectroscopic data requirements for the planned upper atmosphere research satellite (UARS) mission, review of the status of currently available spectroscopic parameters, and recommendation of additional studies. The objectives were accomplished and resulted in a series of general and specific recommendations for laboratory spectroscopy research to meet the needs of UARS and other atmospheric remote sensing programs.

Characterizing Sky Spectra Using SDSS BOSS Data

NASA Astrophysics Data System (ADS)

Florez, Lina Maria; Strauss, Michael A.

2018-01-01

In the optical/near-infrared spectra gathered by a ground-based telescope observing very faint sources, the strengths of the emission lines due to the Earth’s atmosphere can be many times larger than the fluxes of the sources we are interested in. Thus the limiting factor in faint-object spectroscopy is the degree to which systematics in the sky subtraction can be minimized. Longwards of 6000 Angstroms, the night-sky spectrum is dominated by multiple vibrational/rotational transitions of the OH radical from our upper atmosphere. While the wavelengths of these lines are the same in each sky spectrum, their relative strengths vary considerably as a function of time and position on the sky. The better we can model their strengths, the better we can hope to subtract them off. We expect that the strength of lines from common upper energy levels will be correlated with one another. We used flux-calibrated sky spectra from the Sloan Digital Sky Survey Baryon Oscillation Spectroscopic Survey (SDSS BOSS) to explore these correlations. Our aim is to use these correlations for creating improved sky subtraction algorithms for the Prime Focus Spectrograph (PFS) on the 8.2-meter Subaru Telescope. When PFS starts gathering data in 2019, it will be the most powerful multi-object spectrograph in the world. Since PFS will be gathering data on sources as faint as 24th magnitude and fainter, it's of upmost importance to be able to accurately measure and subtract sky spectra from the data that we receive.

Space Shuttle ice nuclei

NASA Astrophysics Data System (ADS)

Turco, R. P.; Toon, O. B.; Whitten, R. C.; Cicerone, R. J.

1982-08-01

Estimates are made showing that, as a consequence of rocket activity in the earth's upper atmosphere in the Shuttle era, average ice nuclei concentrations in the upper atmosphere could increase by a factor of two, and that an aluminum dust layer weighing up to 1000 tons might eventually form in the lower atmosphere. The concentrations of Space Shuttle ice nuclei (SSIN) in the upper troposphere and lower stratosphere were estimated by taking into account the composition of the particles, the extent of surface poisoning, and the size of the particles. Calculated stratospheric size distributions at 20 km with Space Shuttle particulate injection, calculated SSIN concentrations at 10 and 20 km altitude corresponding to different water vapor/ice supersaturations, and predicted SSIN concentrations in the lower stratosphere and upper troposphere are shown.

NASA's Upper Atmosphere Research Program UARP and Atmospheric Chemistry Modeling and Analysis Program (ACMAP): Research Summaries 1994 - 1996. Report to Congress and the Environmental Protection Agency

NASA Technical Reports Server (NTRS)

Kendall, Rose (Compiler); Wolfe, Kathy (Compiler)

1997-01-01

Under the mandate contained in the FY 1976 NASA Authorization Act, the National Aeronautics and Space Administration (NASA) has developed and is implementing a comprehensive program of research, technology, and monitoring of the Earth's upper atmosphere, with emphasis on the stratosphere. This program aims at expanding our understanding to permit both the quantitative analysis of current perturbations as well as the assessment of possible future changes in this important region of our environment. It is carried out jointly by the Upper Atmosphere Research Program (UARP) and the Atmospheric Chemistry Modeling and Analysis Program (ACMAP), both managed within the Science Division in the Office of Mission to Planet Earth at NASA. Significant contributions to this effort are also provided by the Atmospheric Effects of Aviation Project (AEAP) of NASA's Office of Aeronautics. The long-term objectives of the present program are to perform research to: understand the physics, chemistry, and transport processes of the upper atmosphere and their effect on the distribution of chemical species in the stratosphere, such as ozone; understand the relationship of the trace constituent composition of the lower stratosphere and the lower troposphere to the radiative balance and temperature distribution of the Earth's atmosphere; and accurately assess possible perturbations of the upper atmosphere caused by human activities as well as by natural phenomena. In compliance with the Clean Air Act Amendments of 1990, Public Law 101-549, NASA has prepared a report on the state of our knowledge of the Earth's upper atmosphere, particularly the stratosphere, and on the progress of UARP and ACMAP. The report for the year 1996 is composed of two parts. Part 1 summarizes the objectives, status, and accomplishments of the research tasks supported under NASA UARP and ACMAP in a document entitled, Research Summary 1994-1996. Part 2 is entitled Present State of Knowledge of the Upper Atmosphere 1996.- An Assessment Report. It consists primarily of the Executive Summary and Chapter Summaries of the World Meteorological Organization Global Ozone Research and Monitoring Project Report No. 37, Scientific Assessment of Ozone Depletion: 1994, sponsored by NASA, the National Oceanic and Atmospheric Administration (NOAA), the UK Department of the Environment, the United Nations Environment Program, and the World Meteorological Organization. Other sections of Part 11 include summaries of the following: an Atmospheric Ozone Research Plan from NASA's Office of Mission to Planet Earth; summaries from a series of Space Shuttle-based missions and two recent airborne measurement campaigns; the Executive Summary of the 1995 Scientific Assessment of the Atmospheric Effects of Stratospheric Aircraft, and the most recent evaluation of photochemical and chemical kinetics data (Evaluation No. 12 of the NASA Panel for Data Evaluation) used as input parameters for atmospheric models.

Obituary: Lloyd V. Wallace (1927 - 2015)

NASA Astrophysics Data System (ADS)

Born in 1927 in Detroit, Michigan, in humble circumstances, Lloyd developed an early interest in solar and planetary astronomy and was a protégé of Ralph Nichols, a physics professor at the University of Western Ontario. Later he moved back to the United States and obtained his Ph.D in Astronomy at the University of Michigan in 1957 under Leo Goldberg. It was while he was at the University of Michigan that he met and married his wife, Ruth. At various times in his early career, and as the result of a complex series of events, he held Canadian, British, and United States citizenships and even found time to become an expert professional electrician. On acquiring his degree he obtained a position with Joe Chamberlain at the Yerkes Observatory and began a lifetime association with Chamberlain and Don Hunten (then a visitor to Yerkes) in atmospheric and spectroscopic research. In 1962 they moved to Tucson where Chamberlain became the head of the Space Division at the Kitt Peak National Observatory, a unit set up by the first director, Aden Meinel, to apply advances in technology to astronomical research. Lloyd was hired as the principal experimenter in the observatory's sounding rocket program, which was set up by the National Science Foundation to provide staff and visitor access to the upper atmosphere for research purposes. With this program he supervised a series of 39 Aerobee rocket flights from the White Sands Missile range to investigate upper atmosphere emissions, aeronomic processes, and make astronomical observations over a period of about 10 years. He was also involved in the first attempts to establish a remotely controlled 50&rdquo telescope on Kitt Peak and efforts within the Division to create an Earth orbiting astronomical telescope. In parallel with these activities Lloyd conducted research which was largely focused on spectroscopic investigations. In the early days these included measurement of upper atmospheric emissions, particularly visual dayglow, the discovery of Raman lines in Uranus, Lightning spectrum, and auroral emissions. During this time he also pursued theoretical studies of resonant line transfer and some of the first modelling of the thermal structure of outer planet atmospheres. With the conclusion of the rocket program he turned his attention to high-resolution studies of the sun and cool stars and to long-term study of the variability of atmospheric pollutants (HCl, HF. CO2) over Kitt Peak. His solar and cool star studies led to the production of several high-resolution digital atlases extending from the UV to the thermal IR, and in addition, studies of line variability and the molecular content of sunspots. Lloyd was a very private and genuine person, but with a very sharp wit. He was highly productive with 135 published papers bearing his name.

Large Abundances of Polycyclic Aromatic Hydrocarbons in Titan's Upper Atmosphere

NASA Technical Reports Server (NTRS)

Lopez-Puertas, M.; Dinelli, B. M.; Adriani, A.; Funke, B.; Garcia-Comas, M.; Moriconi, M. L.; D'Aversa, E.; Boersma, C.; Allamandola, L. J.

2013-01-01

In this paper, we analyze the strong unidentified emission near 3.28 micron in Titan's upper daytime atmosphere recently discovered by Dinelli et al.We have studied it by using the NASA Ames PAH IR Spectroscopic Database. The polycyclic aromatic hydrocarbons (PAHs), after absorbing UV solar radiation, are able to emit strongly near 3.3 micron. By using current models for the redistribution of the absorbed UV energy, we have explained the observed spectral feature and have derived the vertical distribution of PAH abundances in Titan's upper atmosphere. PAHs have been found to be present in large concentrations, about (2-3) × 10(exp 4) particles / cubic cm. The identified PAHs have 9-96 carbons, with a concentration-weighted average of 34 carbons. The mean mass is approx 430 u; the mean area is about 0.53 sq. nm; they are formed by 10-11 rings on average, and about one-third of them contain nitrogen atoms. Recently, benzene together with light aromatic species as well as small concentrations of heavy positive and negative ions have been detected in Titan's upper atmosphere. We suggest that the large concentrations of PAHs found here are the neutral counterpart of those positive and negative ions, which hence supports the theory that the origin of Titan main haze layer is located in the upper atmosphere.

Benchmark solutions for the galactic ion transport equations: Energy and spatially dependent problems

NASA Technical Reports Server (NTRS)

Ganapol, Barry D.; Townsend, Lawrence W.; Wilson, John W.

1989-01-01

Nontrivial benchmark solutions are developed for the galactic ion transport (GIT) equations in the straight-ahead approximation. These equations are used to predict potential radiation hazards in the upper atmosphere and in space. Two levels of difficulty are considered: (1) energy independent, and (2) spatially independent. The analysis emphasizes analytical methods never before applied to the GIT equations. Most of the representations derived have been numerically implemented and compared to more approximate calculations. Accurate ion fluxes are obtained (3 to 5 digits) for nontrivial sources. For monoenergetic beams, both accurate doses and fluxes are found. The benchmarks presented are useful in assessing the accuracy of transport algorithms designed to accommodate more complex radiation protection problems. In addition, these solutions can provide fast and accurate assessments of relatively simple shield configurations.

Effects of Lightning in the Upper Atmosphere

NASA Astrophysics Data System (ADS)

Sentman, Davis D.; Pasko, Victor P.; Morrill, Jeff S.

2010-02-01

AGU Chapman Conference on Effects of Thunderstorms and Lightning in the Upper Atmosphere; University Park, Pennsylvania, 10-14 May 2009; The serendipitous observation in 1989 of electrical discharge in the high atmosphere induced by thundercloud lightning launched a new field of geophysical investigation. From this single unexpected observation sprang a vigorous and fertile new research field that simultaneously encompasses geophysical disciplines that are normally pursued independently, such as meteorology and lightning, plasma and gas discharge physics, atmospheric chemistry, ionospheric physics, and energetic particle physics. Transient electrical discharge in the upper atmosphere spans the full range of altitudes between the tropopause and the ionosphere and takes a variety of forms that carry the whimsical names red sprites, blue jets, gigantic jets, elves (emissions of light and very low frequency perturbations from electromagnetic pulse sources), and sprite halos, collectively known as transient luminous events (TLEs). To date, TLEs have been observed from ground and airborne or spaceborne platforms above thunderstorm systems worldwide, and radio observations made concomitantly with optical observations have shown that they are produced by the transient far fields of thundercloud lightning. TLEs appear to be large-scale (tens of kilometers in dimension), upper atmospheric versions of conventional gas discharge akin to weakly ionized, collision-dominated systems found in laboratory discharge devices (millimeter-centimeter dimensions), with characteristic energies of a few electron volts. The dominant physical processes have been identified as described by the familiar kinetic theory of the photochemistry of the upper atmosphere, but with electric field-driven electron impact ionization playing the role of photolysis or energetic precipitating particle-induced ionization.

The precipitation of energetic heavy ions into the upper atmosphere of Jupiter

NASA Technical Reports Server (NTRS)

Horanyi, M.; Cravens, T. E.; Waite, J. H., Jr.

1987-01-01

Evidence for auroral particle precipitation at Jupiter was provided by the ultraviolet spectrometers onboard the Voyagers 1 and 2 spacecraft and by the International Ultraviolet Explorer (IUE). Magnetospheric measurements made by instruments onboard the Voyager spacecraft show that energetic sulfur and oxygen ions are precipitating into the upper atmosphere of Jupiter. A theoretical model has been constructed describing the interaction of precipitating oxygen with the Jovian atmosphere. The auroral energy is deposited in the atmosphere by means of ionization, excitation, and dissociation and heating of the atmospheric gas. Energetic ion and electron precipitation are shown to have similar effects on the atmosphere and ionosphere of Jupiter.

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

NASA Astrophysics Data System (ADS)

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

2013-12-01

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

Virginia Space Grant Consortium Upper Atmospheric Payload Balloon System (Vps)

NASA Technical Reports Server (NTRS)

Marz, Bryan E.; Ash, Robert L.

1996-01-01

This document provides a summary of the launch and post-launch activities of Virginia Space Grant Consortium Upper Atmospheric Payload Balloon System, V(ps). It is a comprehensive overview covering launch activities, post-launch activities, experimental results, and future flight recommendations.

Study of internal gravity waves in the meteor zone

NASA Technical Reports Server (NTRS)

Gavrilov, N. M.

1987-01-01

An important component of the dynamical regime of the atmosphere at heights near 100 km are internal gravity waves (IGW) with periods from about 5 min to about 17.5 hrs which propagate from the lower atmospheric layers and are generated in the uppermost region of the atmosphere. As IGW propagate upwards, their amplitudes increase and they have a considerable effect on upper atmospheric processes: (1) they provide heat flux divergences comparable with solar heating; (2) they influence the gaseous composition and produce wave variations of the concentrations of gaseous components and emissions of the upper atmosphere; and (3) they cause considerable acceleration of the mean stream. It was concluded that the periods, wavelengths, amplitudes and velocities of IGW propagation in the meteor zone are now measured quite reliably. However, for estimating the influence of IGW on the thermal regime and the circulation of the upper atmosphere these parameters are not as important as the values of wave fluxes of energy, heat, moment and mass.

The Geospace Dynamics Observatory; a Mission of Discovery for Geospace

NASA Technical Reports Server (NTRS)

Spann, James; Paxton, Larry; Burch, James; Reardon, Patrick; Krause, Linda; Gallagher, Dennis; Hopkins, Randall

2013-01-01

A few examples of potential advances include: 1. Unparalleled advances in the connection of the upper atmosphere to the Sun. In the aurora and lower latitudes, extending the duration of uninterrupted images would advance understanding of the transfer of energy from the Sun to the upper atmosphere and the response of the space environment. 2. Advances in the influence of waves and tides on the upper atmosphere. Increasing both the signal to noise and the duration ofthe observations would reveal contributions that are not identifiable using other approaches. 3. The ability to probe the mechanisms that control the evolution of planetary atmospheres. The vantage point provided by this mission allows the flux of hydrogen (which is tied to the escape of water from a planet) to be mapped globally. It also allows unique observations of changes in the atmospheric structure and their causes.

Using high-resolution digital aerial imagery to map land cover

USGS Publications Warehouse

Dieck, J.J.; Robinson, Larry

2014-01-01

The Upper Midwest Environmental Sciences Center (UMESC) has used aerial photography to map land cover/land use on federally owned and managed lands for over 20 years. Until recently, that process used 23- by 23-centimeter (9- by 9-inch) analog aerial photos to classify vegetation along the Upper Mississippi River System, on National Wildlife Refuges, and in National Parks. With digital aerial cameras becoming more common and offering distinct advantages over analog film, UMESC transitioned to an entirely digital mapping process in 2009. Though not without challenges, this method has proven to be much more accurate and efficient when compared to the analog process.

Modeled sulfate concentrations in North Dakota streams, 1993-2008, based on spatial basin characteristics

USGS Publications Warehouse

Galloway, Joel M.; Vecchia, Aldo V.

2014-01-01

Modeled sulfate concentrations generally were highest (greater than 750 milligrams per liter) in basins in western North Dakota and lowest (less than 250 milligrams per liter) in basins in the upper Sheyenne River and upper James River. Area-weighted means for the basin characteristics also were computed for 10-digit and 8-digit hydrologic units for streams in North Dakota and modeled sulfate concentrations were computed from the characteristics. The resulting distribution of modeled sulfate concentrations was similar to the distribution of estimates for the 12-digit hydrologic units, but less variable because the basin characteristics were averaged over larger areas.

The upper atmosphere of Uranus

NASA Technical Reports Server (NTRS)

Strobel, Darrell F.; Yelle, Roger V.; Shemansky, Donald E.; Atreya, Sushil K.

1991-01-01

Voyager measurements of the upper atmosphere of Uranus are analyzed and developed. The upper atmosphere of Uranus is predominantly H2, with at most 10 percent He by volume, and the dominant constituent of the exosphere is H. The thermosphere is warm, with an asymptotic isothermal temperature of about 800 K. Atomic hydrogen at this temperature forms an extensive thermal corona and creates gas drag that severely limits the lifetime of small ring particles. The upper atmosphere emits copious amounts of UV radiation from pressures greater than 0.01 microbar. The depth of this emission level imposes a powerful constraint on permissible emission mechanisms. Electron excitation from a thin layer near the exobase appears to violate this constraint. Solar fluorescence is consistent with the observed trend in solar zenith-angle variation of the emissions and is absent from the night side of the planet. On Uranus, it accounts for the observed Lyman beta to H2 bands intensity ratio and an important fraction of the observed intensity (about 55 percent).

Present state of knowledge of the upper atmosphere 1990: An assessment report

NASA Technical Reports Server (NTRS)

Watson, R. T.; Kurylo, M. J.; Prather, M. J.; Ormond, F. M.

1990-01-01

NASA is charged with the responsibility to report on the state of the knowledge of the Earth's upper atmosphere, particularly the stratosphere. Part 1 of this report, issued earlier this year, summarized the objectives, status, and accomplishments of the research tasks supported under NASA's Upper Atmosphere Research Program during the last two years. New findings since the last report to Congress was issued in 1988 are presented. Several scientific assessments of the current understanding of the chemical composition and physical structure of the stratosphere are included, in particular how the abundance and distribution of ozone is predicted to change in the future. These reviews include: a summary of the most recent international assessment of stratospheric ozone; a study of future chlorine and bromine loading of the atmosphere; a review of the photochemical and chemical kinetics data that are used as input parameters for the atmospheric models; a new assessment of the impact of Space Shuttle launches on the stratosphere; a summary of the environmental issues and needed research to evaluate the impact of the newly re-proposed fleet of stratospheric supersonic civil aircraft; and a list of the contributors to this report and the science assessments which have formed our present state of knowledge of the upper atmosphere and ozone depletion.

Venus Atmospheric Maneuverable Platform (VAMP)

NASA Astrophysics Data System (ADS)

Griffin, K.; Sokol, D.; Lee, G.; Dailey, D.; Polidan, R.

2013-12-01

We have explored a possible new approach to Venus upper atmosphere exploration by applying recent Northrop Grumman (non-NASA) development programs to the challenges associated with Venus upper atmosphere science missions. Our concept is a low ballistic coefficient (<50 Pa), semi-buoyant aircraft that deploys prior to entering the Venus atmosphere, enters the Venus atmosphere without an aeroshell, and provides a long-lived (months to years), maneuverable vehicle capable of carrying science payloads to explore the Venus upper atmosphere. In 2012 we initiated a feasibility study for a semi-buoyant maneuverable vehicle that could operate in the upper atmosphere of Venus. In this presentation we report results from the ongoing study and plans for future analyses and prototyping to advance and refine the concept. We will discuss the overall mission architecture and concept of operations from launch through Venus arrival, orbit, entry, and atmospheric science operations. We will present a strawman concept of VAMP, including ballistic coefficient, planform area, percent buoyancy, inflation gas, wing span, vehicle mass, power supply, propulsion, materials considerations, structural elements, subsystems, and packaging. The interaction between the VAMP vehicle and the supporting orbiter will also be discussed. In this context, we will specifically focus upon four key factors impacting the design and performance of VAMP: 1. Feasibility of and options for the deployment of the vehicle in space 2. Entry into the Venus atmosphere, including descent profile, heat rate, total heat load, stagnation temperature, control, and entry into level flight 3. Characteristics of flight operations and performance in the Venus atmosphere: altitude range, latitude and longitude access, day/night performance, aircraft performance (aerodynamics, power required vs. power available, propulsion, speed, percent buoyancy), performance sensitivity to payload weight 4. Science payload accommodation, constraints, and opportunities We will discuss interdependencies of the above factors and the manner in which the VAMP strawman's characteristics affect the CONOPs and the science objectives. We will show how the these factors provide constraints as well as enable opportunities for novel long duration scientific studies of the Venus upper atmosphere that support VEXAG goals 2 and 3. We will also discuss how the VAMP platform itself can facilitate some of these science measurements.

Space Shuttle Projects

NASA Image and Video Library

1992-09-12

This STS-48 onboard photo is of the Upper Atmosphere Research Satellite (UARS) in the grasp of the RMS (Remote Manipulator System) during deployment, September 1991. UARS gathers data related to the chemistry, dynamics, and energy of the ozone layer. UARS data is used to study energy input, stratospheric photo chemistry, and upper atmospheric circulation. UARS helps us understand and predict how the nitrogen and chlorine cycles, and the nitrous oxides and halo carbons which maintain them, relate to the ozone balance. It also observes diurnal variations in short-lived stratospheric chemical species important to ozone destruction. Data from UARS enables scientists to study ozone depletion in the upper atmosphere.

Space Shuttle Projects

NASA Image and Video Library

1991-09-12

This STS-48 onboard photo is of the Upper Atmosphere Research Satellite (UARS) in the grasp of the RMS (Remote Manipulator System) during deployment, September 1991. UARS gathers data related to the chemistry, dynamics, and energy of the ozone layer. UARS data is used to study energy input, stratospheric photo chemistry, and upper atmospheric circulation. UARS helps us understand and predict how the nitrogen and chlorine cycles, and the nitrous oxides and halo carbons which maintain them, relate to the ozone balance. It also observes diurnal variations in short-lived stratospheric chemical species important to ozone destruction. Data from UARS enables scientists to study ozone depletion in the upper atmosphere.

DIGITAL Q METER

DOEpatents

Briscoe, W.L.

1962-02-13

A digital Q meter is described for measuring the Q of mechanical or electrical devices. The meter comprises in combination a transducer coupled to an input amplifier, and an upper and lower level discriminator coupled to the amplifier and having their outputs coupled to an anticoincidence gate. The output of the gate is connected to a scaler. The lower level discriminator is adjusted to a threshold level of 36.8 percent of the operating threshold level of the upper level discriminator. (AEC)

Theoretical and experimental investigations of upper atmosphere dynamics

NASA Technical Reports Server (NTRS)

Roper, R. G.; Edwards, H. D.

1980-01-01

A brief overview of the significant contributions made to the understanding of the dynamics of the Earth's upper atmosphere is presented, including the addition of winds and diffusion to the semi-empirical Global Reference Atmospheric Model developed for the design phase of the Space Shuttle, reviews of turbulence in the lower thermosphere, the dynamics of the equatorial mesopause, stratospheric warming effects on mesopause level dynamics, and the relevance of these studies to the proposed Middle Atmosphere Program (1982-85). A chronological bibliography, with abstracts of all papers published, is also included.

Dynamics of the Venus upper atmosphere: Outstanding problems and new constraints expected from Venus Express

NASA Astrophysics Data System (ADS)

Bougher, S. W.; Rafkin, S.; Drossart, P.

2006-11-01

A consistent picture of the dynamics of the Venus upper atmosphere from ˜90 to 200 km has begun to emerge [e.g., Bougher, S.W., Alexander, M.J., Mayr, H.G., 1997. Upper Atmosphere Dynamics: Global Circulation and Gravity Waves. Venus II, CH. 2.4. University of Arizona Press, Tucson, pp. 259-292; Lellouch, E., Clancy, T., Crisp, D., Kliore, A., Titov, D., Bougher, S.W., 1997. Monitoring of Mesospheric Structure and Dynamics. Venus II, CH. 3.1. University of Arizona Press, Tucson, pp. 295-324]. The large-scale circulation of the Venus upper atmosphere (upper mesosphere and thermosphere) can be decomposed into two distinct flow patterns: (1) a relatively stable subsolar-to-antisolar (SS-AS) circulation cell driven by solar heating, and (2) a highly variable retrograde superrotating zonal (RSZ) flow. Wave-like perturbations have also been observed. However, the processes responsible for maintaining (and driving variations in) these SS-AS and RSZ winds are not well understood. Variations in winds are thought to result from gravity wave breaking and subsequent momentum and energy deposition in the upper atmosphere [Alexander, M.J., 1992. A mechanism for the Venus thermospheric superrotation. Geophys. Res. Lett. 19, 2207-2210; Zhang, S., Bougher, S.W., Alexander, M.J., 1996. The impact of gravity waves on the Venus thermosphere and O2 IR nightglow. J. Geophys. Res. 101, 23195-23205]. However, existing data sets are limited in their spatial and temporal coverage, thereby restricting our understanding of these changing circulation patterns. One of the major goals of the Venus Express (VEX) mission is focused upon increasing our understanding of the circulation and dynamical processes of the Venus atmosphere up to the exobase [Titov, D.V., Lellouch, E., Taylor, F.W., 2001. Venus Express: Response to ESA's call for ideas for the re-use of the Mars Express platform. Proposal to European Space Agency, 1-74]. Several VEX instruments are slated to obtain remote measurements (2006-2008) that will complement those obtained earlier by the Pioneer Venus Orbiter (PVO) between 1978 and 1992. These VEX measurements will provide a more comprehensive investigation of the Venus upper atmosphere (90-200 km) structure and dynamics over another period in the solar cycle and for variable lower atmosphere conditions. An expanded climatology of Venus upper atmosphere structure and wind components will be developed. In addition, gravity wave parameters above the cloud tops will be measured (or inferred), and used to constrain gravity wave breaking models. In this manner, the gravity wave breaking mechanism (thought to regulate highly variable RSZ winds) can be tested using Venus general circulation models (GCMs).

Spatial and Temporal Variability of Surface Energy Fluxes During Autumn Ice Advance: Observations and Model Validation

NASA Astrophysics Data System (ADS)

Persson, O. P. G.; Blomquist, B.; Grachev, A. A.; Guest, P. S.; Stammerjohn, S. E.; Solomon, A.; Cox, C. J.; Capotondi, A.; Fairall, C. W.; Intrieri, J. M.

2016-12-01

From Oct 4 to Nov 5, 2015, the Office of Naval Research - sponsored Sea State cruise in the Beaufort Sea with the new National Science Foundation R/V Sikuliaq obtained extensive in-situ and remote sensing observations of the lower troposphere, the advancing sea ice, wave state, and upper ocean conditions. In addition, a coupled atmosphere, sea ice, upper-ocean model, based on the RASM model, was run at NOAA/PSD in a hindcast mode for this same time period, providing a 10-day simulation of the atmosphere/ice/ocean evolution. Surface energy fluxes quantitatively represent the air-ice, air-ocean, and ice-ocean interaction processes, determining the cooling (warming) rate of the upper ocean and the growth (melting) rate of sea ice. These fluxes also impact the stratification of the lower troposphere and the upper ocean. In this presentation, both direct and indirect measurements of the energy fluxes during Sea State will be used to explore the spatial and temporal variability of these fluxes and the impacts of this variability on the upper ocean, ice, and lower atmosphere during the autumn ice advance. Analyses have suggested that these fluxes are impacted by atmospheric synoptic evolution, proximity to existing ice, ice-relative wind direction, ice thickness and snow depth. In turn, these fluxes impact upper-ocean heat loss and timing of ice formation, as well as stability in the lower troposphere and upper ocean, and hence heat transport to the free troposphere and ocean mixed-layer. Therefore, the atmospheric structure over the advancing first-year ice differs from that over the nearby open water. Finally, these observational analyses will be used to provide a preliminary validation of the spatial and temporal variability of the surface energy fluxes and the associated lower-tropospheric and upper-ocean structures in the simulations.

Internal gravity waves in the upper atmosphere, generated by tropospheric jet streams

NASA Technical Reports Server (NTRS)

Chunchuzov, Y. P.; Torgashin, Y. M.

1979-01-01

A mechanism of internal gravity wave generation by jet streams in the troposphere is considered. Evaluations of the energy and pulse of internal gravity waves emitted into the upper atmosphere are given. The obtained values of flows can influence the thermal and dynamic regime of these layers.

Gone with the Wind: Three Years of MAVEN Measurements of Atmospheric Loss at Mars

NASA Astrophysics Data System (ADS)

Brain, David; MAVEN Team

2017-10-01

The Mars Atmosphere and Volatile EvolutioN (MAVEN) mission is making measurements of the Martian upper atmosphere and near space environment, and their interactions with energy inputs from the Sun. A major goal of the mission is to evaluate the loss of atmospheric gases to space in the present epoch, and over Martian history. MAVEN is equipped with instruments that measure both the neutral and charged upper atmospheric system (thermosphere, ionosphere, exosphere, and magnetosphere), inputs from the Sun (extreme ultraviolet flux, solar wind and solar energetic particles, and interplanetary magnetic field), and escaping atmospheric particles. The MAVEN instruments, coupled with models, allow us to more completely understand the physical processes that control atmospheric loss and the particle reservoirs for loss.Here, we provide an overview of the significant results from MAVEN over approximately 1.5 Mars years (nearly three Earth years) of observation, from November 2014 to present. We argue that the MAVEN measurements tell us that the loss of atmospheric gases to space was significant over Martian history, and present the seasonal behavior of the upper atmosphere and magnetosphere. We also discuss the influence of extreme events such as solar storms, and a variety of new discoveries and observations of the Martian system made by MAVEN.

BOREAS AFM-5 Level-1 Upper Air Network Data

NASA Technical Reports Server (NTRS)

Barr, Alan; Hrynkiw, Charmaine; Newcomer, Jeffrey A. (Editor); Hall, Forrest G. (Editor); Smith, David E. (Technical Monitor)

2000-01-01

The Boreal Ecosystem-Atmosphere Study (BOREAS) Airborne Fluxes and Meteorology (AFM)-5 team collected and processed data from the numerous radiosonde flights during the project. The goals of the AFM-05 team were to provide large-scale definition of the atmosphere by supplementing the existing Atmospheric Environment Service (AES) aerological network, both temporally and spatially. This data set includes basic upper-air parameters collected from the network of upper-air stations during the 1993, 1994, and 1996 field campaigns over the entire study region. The data are contained in tabular ASCII files. The level-1 upper-air network data are available from the Earth Observing System Data and Information System (EOSDIS) Oak Ridge National Laboratory (ORNL) Distributed Active Archive Center (DAAC). The data files also are available on a CD-ROM (see document number 20010000884).

Collaborative Tools in Upper Secondary School--Why?

ERIC Educational Resources Information Center

Mathiasen, Helle; Degn, Hans-Peter; Dalsgaard, Christian; Bech, Christian W.; Gregersen, Claus

2013-01-01

The paper will discuss potentials of digital media to support student engagement and student production in Danish upper secondary education with a specific focus on group work and collaboration. With the latest school reform, upper secondary education in Denmark has experienced an increased focus on problem-based and self-governed work of…

Solar magnetism eXplorer (SolmeX). Exploring the magnetic field in the upper atmosphere of our closest star

NASA Astrophysics Data System (ADS)

Peter, Hardi; Abbo, L.; Andretta, V.; Auchère, F.; Bemporad, A.; Berrilli, F.; Bommier, V.; Braukhane, A.; Casini, R.; Curdt, W.; Davila, J.; Dittus, H.; Fineschi, S.; Fludra, A.; Gandorfer, A.; Griffin, D.; Inhester, B.; Lagg, A.; Landi Degl'Innocenti, E.; Maiwald, V.; Sainz, R. Manso; Martínez Pillet, V; Matthews, S.; Moses, D.; Parenti, S.; Pietarila, A.; Quantius, D.; Raouafi, N.-E.; Raymond, J.; Rochus, P.; Romberg, O.; Schlotterer, M.; Schühle, U.; Solanki, S.; Spadaro, D.; Teriaca, L.; Tomczyk, S.; Trujillo Bueno, J.; Vial, J.-C.

2012-04-01

The magnetic field plays a pivotal role in many fields of Astrophysics. This is especially true for the physics of the solar atmosphere. Measuring the magnetic field in the upper solar atmosphere is crucial to understand the nature of the underlying physical processes that drive the violent dynamics of the solar corona—that can also affect life on Earth. SolmeX, a fully equipped solar space observatory for remote-sensing observations, will provide the first comprehensive measurements of the strength and direction of the magnetic field in the upper solar atmosphere. The mission consists of two spacecraft, one carrying the instruments, and another one in formation flight at a distance of about 200 m carrying the occulter to provide an artificial total solar eclipse. This will ensure high-quality coronagraphic observations above the solar limb. SolmeX integrates two spectro-polarimetric coronagraphs for off-limb observations, one in the EUV and one in the IR, and three instruments for observations on the disk. The latter comprises one imaging polarimeter in the EUV for coronal studies, a spectro-polarimeter in the EUV to investigate the low corona, and an imaging spectro-polarimeter in the UV for chromospheric studies. SOHO and other existing missions have investigated the emission of the upper atmosphere in detail (not considering polarization), and as this will be the case also for missions planned for the near future. Therefore it is timely that SolmeX provides the final piece of the observational quest by measuring the magnetic field in the upper atmosphere through polarimetric observations.

Organic chemistry in Titan's upper atmosphere and its astrobiological consequences: I. Views towards Cassini plasma spectrometer (CAPS) and ion neutral mass spectrometer (INMS) experiments in space

NASA Astrophysics Data System (ADS)

Ali, A.; Sittler, E. C.; Chornay, D.; Rowe, B. R.; Puzzarini, C.

2015-05-01

The discovery of carbocations and carbanions by Ion Neutral Mass Spectrometer (INMS) and the Cassini Plasma Spectrometer (CAPS) instruments onboard the Cassini spacecraft in Titan's upper atmosphere is truly amazing for astrochemists and astrobiologists. In this paper we identify the reaction mechanisms for the growth of the complex macromolecules observed by the CAPS Ion Beam Spectrometer (IBS) and Electron Spectrometer (ELS). This identification is based on a recently published paper (Ali et al., 2013. Planet. Space Sci. 87, 96) which emphasizes the role of Olah's nonclassical carbonium ion chemistry in the synthesis of the organic molecules observed in Titan's thermosphere and ionosphere by INMS. The main conclusion of that work was the demonstration of the presence of the cyclopropenyl cation - the simplest Huckel's aromatic molecule - and its cyclic methyl derivatives in Titan's atmosphere at high altitudes. In this study, we present the transition from simple aromatic molecules to the complex ortho-bridged bi- and tri-cyclic hydrocarbons, e.g., CH2+ mono-substituted naphthalene and phenanthrene, as well as the ortho- and peri-bridged tri-cyclic aromatic ring, e.g., perinaphthenyl cation. These rings could further grow into tetra-cyclic and the higher order ring polymers in Titan's upper atmosphere. Contrary to the pre-Cassini observations, the nitrogen chemistry of Titan's upper atmosphere is found to be extremely rich. A variety of N-containing hydrocarbons including the N-heterocycles where a CH group in the polycyclic rings mentioned above is replaced by an N atom, e.g., CH2+ substituted derivative of quinoline (benzopyridine), are found to be dominant in Titan's upper atmosphere. The mechanisms for the formation of complex molecular anions are discussed as well. It is proposed that many closed-shell complex carbocations after their formation first, in Titan's upper atmosphere, undergo the kinetics of electron recombination to form open-shell neutral radicals. These radical species subsequently might form carbanions via radiative electron attachment at low temperatures with thermal electrons. The classic example is the perinaphthenyl anion in Titan's upper atmosphere. Therefore, future astronomical observations of selected carbocations and corresponding carbanions are required to settle the key issue of molecular anion chemistry on Titan. Other than earth, Titan is the only planetary body in our solar system that is known to have reservoirs of permanent liquids on its surface. The synthesis of complex biomolecules either by organic catalysis of precipitated solutes “on hydrocarbon solvent” on Titan or through the solvation process indeed started in its upper atmosphere. The most notable examples in Titan's prebiotic atmospheric chemistry are conjugated and aromatic polycyclic molecules, N-heterocycles including the presence of imino >Cdbnd N-H functional group in the carbonium chemistry. Our major conclusion in this paper is that the synthesis of organic compounds in Titan's upper atmosphere is a direct consequence of the chemistry of carbocations involving the ion-molecule reactions. The observations of complexity in the organic chemistry on Titan from the Cassini-Huygens mission clearly indicate that Titan is so far the only planetary object in our solar system that will most likely provide an answer to the question of the synthesis of complex biomolecules on the primitive earth and the origin of life.

Cupid's Arrow: An Innovative Nanosat to Sample Venus' Upper Atmosphere

NASA Technical Reports Server (NTRS)

Bienstock, Bernie; Darrach, Murray; Madzunkov, Stojan; Sotin, Christophe

2016-01-01

In NASA's Discovery 2014 AO, the opportunity to propose a Technology Demonstration Opportunity (TDO) to enhance the primary mission was specified. For the Venus Emissivity, Radio Science, InSAR, Topography, and Spectroscopy (VERITAS) mission, we elected to include the Cupid's Arrow nanosat TDO to sample and measure the abundances of noble gases and their isotopic ratios in Venus's upper atmosphere below the homopause. This paper will provide a basic overview of the VERITAS mission, with a focus on the Cupid's Arrow concept including a description of the mission, spacecraft design, and JPL's quadrupole ion trap mass spectrometer (QITMS) instrument specifications and design. In previous planetary entry probe mission designs, particularly at Venus, engineers w ere focused on entry and descent. A landed probe was also proposed for the New Frontiers SAGE mission. For Cupid's Arrow, the nanosat is designed to skim through the upper atmosphere, just below the homopause, in order to sample the atmosphere, perform the analysis, and then exit the atmosphere to transmit its data to the orbiting VERITAS spacecraft. Cupid's Arrow is a compelling addition to the VERITAS geology mission. A key missing link in our understanding of Venus' evolution is the noble gas abundances and their isotopic ratios. Not since Pioneer Venus have these measurements been made in the Venus atmosphere and never in the upper atmosphere, just below the homopause, to the degree of accuracy that will be accomplished by VERITAS' Cupid's Arrow nanosat.Such measurements were ranked as the number 1 investigation of the number 1 objective of the goal "Atmospheric Formation, Evolution, and Climate History ".

The Neutral Gas and Ion Mass Spectrometer on the Mars Atmosphere and Volatile Evolution Mission

NASA Technical Reports Server (NTRS)

Mahaffy, Paul R.; Benna, Mehdi; King, Todd; Harpold, Daniel N.; Arvey, Robert; Barciniak, Michael; Bendt, Mirl; Carrigan, Daniel; Errigo, Therese; Holmes, Vincent;

Solar and terrestrial physics. [effects of solar activities on earth environment

NASA Technical Reports Server (NTRS)

1975-01-01

The effects of solar radiation on the near space and biomental earth, the upper atmosphere, and the magnetosphere are discussed. Data obtained from the OSO satellites pertaining to the solar cycle variation of extreme ultraviolet (EUV) radiation are analyzed. The effects of solar cycle variation of the characteristics of the solar wind are examined. The fluid mechanics of shock waves and the specific relationship to the characteristics of solar shock waves are investigated. The solar and corpuscular heating of the upper atmosphere is reported based on the findings of the AEROS and NATE experiments. Seasonal variations of the upper atmosphere composition are plotted based on OGO-6 mass spectrometer data.

Digital Leisure and Perceived Family Functioning in Youth of Upper Secondary Education

ERIC Educational Resources Information Center

Valdemoros-San-Emeterio, M-Angeles; Sanz-Arazuri, Eva; Ponce-de-León-Elizondo, Ana

2017-01-01

The "Network Society" is identified by accelerated changes that occur between real and virtual worlds. The progress of digital devices has generated a new model of leisure that has conditioned family interactions. The aim of this research was to identify the relationship between digital leisure experiences and perceived family…

MAVEN - Mars Atmosphere and Volatile EvolutioN Mission

NASA Technical Reports Server (NTRS)

Grebowsky, Joseph M.; Jakosky, Bruce M.

2011-01-01

NASA's MAVEN mission (to be launched in late 2013) is the first mission to Mars devoted to sampling all of the upper atmosphere neutral and plasma environments, including the well-mixed atmosphere, the exosphere, ionosphere, outer magnetosphere and near-Mars solar wind. It will fill in some measurement gaps remaining from the successful Mars Global Surveyor and the on-going Mars Express missions. The primary science objectives of MAVEN are: 1. Provide a comprehensive picture of the present state of the upper atmosphere and ionosphere of Mars; 2. Understand the processes controlling the present state; and 3. Determine how loss of volatiles to outer space in the present epoch varies with changing solar condition - EUY, solar wind and interplanetary magnetic field measurements will provide the varying solar energy inputs into the system. Knowing how these processes respond to the Sun's energy inputs in the current epoch will provide a framework for projecting atmospheric processes back in time to profile MARS' atmospheric evolution and to explore "where the water went", A description will be given of the science objectives, the instruments, and the current status of the project, emphasizing the value of having collaborations between the MAVEN project and the Mars upper atmosphere science community.

A SEARCH FOR MAGNESIUM IN EUROPA'S ATMOSPHERE

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hoerst, S. M.; Brown, M. E., E-mail: sarah.horst@colorado.edu

Europa's tenuous atmosphere results from sputtering of the surface. The trace element composition of its atmosphere is therefore related to the composition of Europa's surface. Magnesium salts are often invoked to explain Galileo Near Infrared Mapping Spectrometer spectra of Europa's surface, thus magnesium may be present in Europa's atmosphere. We have searched for magnesium emission in the Hubble Space Telescope Faint Object Spectrograph archival spectra of Europa's atmosphere. Magnesium was not detected and we calculate an upper limit on the magnesium column abundance. This upper limit indicates that either Europa's surface is depleted in magnesium relative to sodium and potassium,more » or magnesium is not sputtered as efficiently resulting in a relative depletion in its atmosphere.« less

Spectroscopic database

NASA Technical Reports Server (NTRS)

Husson, N.; Barbe, A.; Brown, L. R.; Carli, B.; Goldman, A.; Pickett, H. M.; Roche, A. E.; Rothman, L. S.; Smith, M. A. H.

1985-01-01

Several aspects of quantitative atmospheric spectroscopy are considered, using a classification of the molecules according to the gas amounts in the stratosphere and upper troposphere, and reviews of quantitative atmospheric high-resolution spectroscopic measurements and field measurements systems are given. Laboratory spectroscopy and spectral analysis and prediction are presented with a summary of current laboratory spectroscopy capabilities. Spectroscopic data requirements for accurate derivation of atmospheric composition are discussed, where examples are given for space-based remote sensing experiments of the atmosphere: the ATMOS (Atmospheric Trace Molecule) and UARS (Upper Atmosphere Research Satellite) experiment. A review of the basic parameters involved in the data compilations; a summary of information on line parameter compilations already in existence; and a summary of current laboratory spectroscopy studies are used to assess the data base.

Space Experiments with Particle Accelerators: SEPAC

NASA Technical Reports Server (NTRS)

Burch, J. L.; Roberts, W. T.; Taylor, W. W. L.; Kawashima, N.; Marshall, J. A.; Moses, S. L.; Neubert, T.; Mende, S. B.; Choueiri, E. Y.

1994-01-01

The Space Experiments with Particle Accelerators (SEPAC), which flew on the Atmospheric Laboratory for Applications and Science (ATLAS) 1 mission, used new techniques to study natural phenomena in the Earth's upper atmosphere, ionosphere and magnetosphere by introducing energetic perturbations into the system from a high power electron beam with known characteristics. Properties of auroras were studied by directing the electron beam into the upper atmosphere while making measurements of optical emissions. Studies were also performed of the critical ionization velocity phenomenon.

Heterodyne detection of CO2 emission lines and wind velocities in the atmosphere of Venus

NASA Technical Reports Server (NTRS)

Betz, A. L.; Johnson, M. A.; Mclaren, R. A.; Sutton, E. C.

1975-01-01

Strong 10 micrometer line emission from (c-12)(o-16)2 in the upper atmosphere of Venus was detected by heterodyne techniques. Observations of the absolute Doppler shift of the emission features indicate mean zonal wind velocities less than 10 m/sec in the upper atmosphere near the equator. No evidence was found of the 100 m/sec wind velocity implied by the apparent 4-day rotation period of ultraviolet cloud features.

Double blanket effect caused by two layers of black carbon aerosols escalates warming in the Brahmaputra River Valley.

PubMed

Rahul, P R C; Bhawar, R L; Ayantika, D C; Panicker, A S; Safai, P D; Tharaprabhakaran, V; Padmakumari, B; Raju, M P

2014-01-14

First ever 3-day aircraft observations of vertical profiles of Black Carbon (BC) were obtained during the Cloud Aerosol Interaction and Precipitation Enhancement Experiment (CAIPEEX) conducted on 30(th) August, 4(th) and 6(th) September 2009 over Guwahati (26° 11'N, 91° 44'E), the largest metropolitan city in the Brahmaputra River Valley (BRV) region. The results revealed that apart from the surface/near surface loading of BC due to anthropogenic processes causing a heating of 2 K/day, the large-scale Walker and Hadley atmospheric circulations associated with the Indian summer monsoon help in the formation of a second layer of black carbon in the upper atmosphere, which generates an upper atmospheric heating of ~2 K/day. Lofting of BC aerosols by these large-scale circulating atmospheric cells to the upper atmosphere (4-6 Km) could also be the reason for extreme climate change scenarios that are being witnessed in the BRV region.

Generation of atmospheric wavefronts using binary micromirror arrays.

PubMed

Anzuola, Esdras; Belmonte, Aniceto

2016-04-10

To simulate in the laboratory the influence that a turbulent atmosphere has on light beams, we introduce a practical method for generating atmospheric wavefront distortions that considers digital holographic reconstruction using a programmable binary micromirror array. We analyze the efficiency of the approach for different configurations of the micromirror array and experimentally demonstrate the benchtop technique. Though the mirrors on the digital array can only be positioned in one of two states, we show that the holographic technique can be used to devise a wide variety of atmospheric wavefront aberrations in a controllable and predictable way for a fraction of the cost of phase-only spatial light modulators.

Neutron spectral measurements in the upper atmosphere

NASA Technical Reports Server (NTRS)

Zobel, W.; Love, T. A.; Delorenzo, J. T.; Mcnew, C. O.

1972-01-01

An experiment to measure neutrons in the upper atmosphere was performed on a balloon flight from Palestine, Texas, at an altitude of about 32 km. The experimental arrangement is discussed briefly, and results of a preliminary analysis of the data for neutrons in the energy range 3 to 30 MeV are given.

Aeronomy of the Venus Upper Atmosphere

NASA Astrophysics Data System (ADS)

Gérard, J.-C.; Bougher, S. W.; López-Valverde, M. A.; Pätzold, M.; Drossart, P.; Piccioni, G.

2017-11-01

We present aeronomical observations collected using remote sensing instruments on board Venus Express, complemented with ground-based observations and numerical modeling. They are mostly based on VIRTIS and SPICAV measurements of airglow obtained in the nadir mode and at the limb above 90 km. They complement our understanding of the behavior of Venus' upper atmosphere that was largely based on Pioneer Venus observations mostly performed over thirty years earlier. Following a summary of recent spectral data from the EUV to the infrared, we examine how these observations have improved our knowledge of the composition, thermal structure, dynamics and transport of the Venus upper atmosphere. We then synthesize progress in three-dimensional modeling of the upper atmosphere which is largely based on global mapping and observations of time variations of the nitric oxide and O2 nightglow emissions. Processes controlling the escape flux of atoms to space are described. Results based on the VeRA radio propagation experiment are summarized and compared to ionospheric measurements collected during earlier space missions. Finally, we point out some unsolved and open questions generated by these recent datasets and model comparisons.

Tracing Acoustic-Gravity Waves from the Ocean into the Ionosphere

NASA Astrophysics Data System (ADS)

Zabotin, N. A.; Godin, O. A.; Bullett, T. W.; Negrea, C.

2013-12-01

Ionospheric manifestations of tsunamis provide dramatic evidence of a connection between wave processes in the ocean and in the atmosphere. But tsunamis are only a transient feature of a more general phenomenon, infragravity waves (IGWs). IGWs are permanently present surface gravity waves in the ocean with periods longer than the longest periods (~30 s) of wind-generated waves. IGWs propagate transoceanic distances and, because of their long wavelengths (from ~1 km to hundreds of km), provide a mechanism for coupling wave processes in the ocean, atmosphere, and the solid Earth. The notion that tsunamis may generate waves in the upper atmosphere has existed for a long time but no quantitative coupling theory for the background waves has been proposed. We provide a strict physical justification for the influence of the background IGWs on the upper atmosphere. Taking into account both fluid compressibility and the gravity in a coupled atmosphere-ocean system, we show that there exist two distinct regimes of IGW penetration into the atmosphere. At higher frequencies, one has evanescent waves in the atmosphere propagating horizontally along the ocean surface. At lower frequencies, IGWs continuously radiate their energy into the upper atmosphere in the form of acoustic gravity waves (AGWs). The transition frequency depends on the ocean depth; it varies slowly near 3 mHz for typical depth values and drops to zero sharply only for extremely large depths. Using semi-empirical model of the IGW power spectrum, we derive an estimate of the flux of the mechanical energy and mechanical momentum from the deep ocean into the atmosphere due to background IGWs and predict specific forcing on the atmosphere in coastal regions. We compare spectra of wave processes in the ionosphere measured using Dynasonde technique over Wallops Island, VA and San Juan, PR and interpret the differences in terms of the oceanic effects. We conclude that AGWs of oceanic origin may have an observable impact on the upper atmosphere and describe techniques for experimental verification of this finding.

Cassini versus Saturn Illustration

NASA Image and Video Library

2017-04-04

As depicted in this illustration, Cassini will plunge into Saturn's atmosphere on Sept. 15, 2017. Using its attitude control thrusters, the spacecraft will work to keep its antenna pointed at Earth while it sends its final data, including the composition of Saturn's upper atmosphere. The atmospheric torque will quickly become stronger than what the thrusters can compensate for, and after that point, Cassini will begin to tumble. When this happens, its radio connection to Earth will be severed, ending the mission. Following loss of signal, the spacecraft will burn up like a meteor in Saturn's upper atmosphere. https://photojournal.jpl.nasa.gov/catalog/PIA21440

Concentrations of ethane (C2H6) in the lower stratosphere and upper troposphere and acetylene (C2H2) in the upper troposphere deduced from Atmospheric Trace Molecule Spectroscopy/Spacelab 3 spectra

NASA Technical Reports Server (NTRS)

Rinsland, C. P.; Russell, J. M., III; Zander, R.; Farmer, C. B.; Norton, R. H.

1987-01-01

This paper reports the results of the spectroscopic analysis of C2H6 and C2H2 absorption spectra obtained by the Atmospheric Trace Molecule Spectroscopy (ATMOS) instrument flown on the Shuttle as part of the Spacelab 3 mission. The spectra were recorded during sunset occultations occurring between 25 deg N and 31 deg N latitudes, yielding volume-mixing ratio profiles of C2H6 in the lower stratosphere and the upper troposphere, and an upper tropospheric profile of C2H2. These results compare well with previous in situ and remote sounding data obtained at similar latitudes and with model calculations. The results demonstrate the feasibility of the ATMOS instrument to sound the lower atmosphere from space.

Estimation of absolute water surface temperature based on atmospherically corrected thermal infrared multispectral scanner digital data

NASA Technical Reports Server (NTRS)

Anderson, James E.

1986-01-01

Airborne remote sensing systems, as well as those on board Earth orbiting satellites, sample electromagnetic energy in discrete wavelength regions and convert the total energy sampled into data suitable for processing by digital computers. In general, however, the total amount of energy reaching a sensor system located at some distance from the target is composed not only of target related energy, but, in addition, contains a contribution originating from the atmosphere itself. Thus, some method must be devised for removing or at least minimizing the effects of the atmosphere. The LOWTRAN-6 Program was designed to estimate atmospheric transmittance and radiance for a given atmospheric path at moderate spectral resolution over an operational wavelength region from 0.25 to 28.5 microns. In order to compute the Thermal Infrared Multispectral Scanner (TIMS) digital values which were recorded in the absence of the atmosphere, the parameters derived from LOWTRAN-6 are used in a correction equation. The TIMS data were collected at 1:00 a.m. local time on November 21, 1983, over a recirculating cooling pond for a power plant in southeastern Mississippi. The TIMS data were analyzed before and after atmospheric corrections were applied using a band ratioing model to compute the absolute surface temperature of various points on the power plant cooling pond. The summarized results clearly demonstrate the desirability of applying atmospheric corrections.

Doppler Data and Density Profile from Cassini Saturn Atmospheric Entry

NASA Astrophysics Data System (ADS)

Wong, M.; Boone, D.; Roth, D. C.

2017-12-01

After thirteen years of surveying the Saturnian system and providing a multitude of ground-breaking science data, the Cassini spacecraft will perform its final act on September 15, 2017 when it plunges into Saturn's upper atmosphere. This `close contact' with uncharted territory will deliver sets of data about Saturn that were not previously obtainable. In addition to new information obtained from various science instruments onboard, the doppler signal, primarily used for navigation purposes throughout the tour, will in this circumstance furnish a glimpse of the atmospheric density along Cassini's path through the upper atmosphere. In this talk we will discuss preliminary results from our analysis of the doppler data and its implication on the atmospheric density.

Digital atlas of the upper Washita River basin, southwestern Oklahoma

USGS Publications Warehouse

Becker, Carol J.; Masoner, Jason R.; Scott, Jonathon C.

2008-01-01

Numerous types of environmental data have been collected in the upper Washita River basin in southwestern Oklahoma. However, to date these data have not been compiled into a format that can be comprehensively queried for the purpose of evaluating the effects of various conservation practices implemented to reduce agricultural runoff and erosion in parts of the upper Washita River basin. This U.S. Geological Survey publication, 'Digital atlas of the upper Washita River basin, southwestern Oklahoma' was created to assist with environmental analysis. This atlas contains 30 spatial data sets that can be used in environmental assessment and decision making for the upper Washita River basin. This digital atlas includes U.S. Geological Survey sampling sites and associated water-quality, biological, water-level, and streamflow data collected from 1903 to 2005. The data were retrieved from the U.S. Geological Survey National Water Information System database on September 29, 2005. Data sets are from the Geology, Geography, and Water disciplines of the U.S. Geological Survey and cover parts of Beckham, Caddo, Canadian, Comanche, Custer, Dewey, Grady, Kiowa, and Washita Counties in southwestern Oklahoma. A bibliography of past reports from the U.S. Geological Survey and other State and Federal agencies from 1949 to 2004 is included in the atlas. Additionally, reports by Becker (2001), Martin (2002), Fairchild and others (2004), and Miller and Stanley (2005) are provided in electronic format.

Digital equalization of time-delay array receivers on coherent laser communications.

PubMed

Belmonte, Aniceto

2017-01-15

Field conjugation arrays use adaptive combining techniques on multi-aperture receivers to improve the performance of coherent laser communication links by mitigating the consequences of atmospheric turbulence on the down-converted coherent power. However, this motivates the use of complex receivers as optical signals collected by different apertures need to be adaptively processed, co-phased, and scaled before they are combined. Here, we show that multiple apertures, coupled with optical delay lines, combine retarded versions of a signal at a single coherent receiver, which uses digital equalization to obtain diversity gain against atmospheric fading. We found in our analysis that, instead of field conjugation arrays, digital equalization of time-delay multi-aperture receivers is a simpler and more versatile approach to accomplish reduction of atmospheric fading.

Role of Earth's plasmasphere in coupling of upper atmosphere

NASA Astrophysics Data System (ADS)

Singh, A. K.; Mishra, Sandhya; Dohare, S. K.

2010-02-01

The near-Earth space environment is a complex, ever changing system of magnetized plasmas whose behaviour has a profound impact upon our technology dependent society. The exploration of the cold, relatively dense, inner region of upper atmosphere (the plasmasphere) and its unexpectedly sharp outer boundary (the plasma pause) has proceeded through a combination of in-situ observations and ground based whistler observations. Studies have shown that plasmasphere is highly variable both spatially and temporally responding to changes in geomagnetic indices, ring current, penetration and shielding electric fields and subauroral electric fields. Consequently the plasmasphere exhibits erosion, emptying and refilling during active times. Infact, it is the electric field that plays one of the most important roles in coupling of upper atmosphere. The atmospheric dynamo is the main generator of the large-scale electric field in the upper atmosphere. It arises because of a special situation which electrons and ions move with different velocities across the magnetic field because of different collisions between electrons and neutral particles and ions with neutral particles. This process leads to charge separation and consequently to an electric field. In the present paper, storm/ quiet period VLF whistler data recorded at lower latitudes/mid latitudes are analyzed and attempt has been made to look at plasmasphere response on coupling of ionosphere and magnetosphere.

Extending the NASA Ames Mars General Circulation Model to Explore Mars’ Middle Atmosphere

NASA Astrophysics Data System (ADS)

Brecht, Amanda; Hollingsworth, J.; Kahre, M.; Schaeffer, J.

2013-10-01

The NASA Ames Mars General Circulation Model (MGCM) upper boundary has been extended to ~120 km altitude (p ~10-5 mbar). The extension of the MGCM upper boundary initiates the ability to understand the connection between the lower and upper atmosphere of Mars through the middle atmosphere 70 - 120 km). Moreover, it provides the opportunity to support future missions (i.e. the 2013 MAVEN mission). A major factor in this extension is the incorporation of the Non-Local Thermodynamic Equilibrium (NLTE) heating (visible) and cooling (infrared). This modification to the radiative transfer forcing (i.e., RT code) has been significantly tested in a 1D vertical column and now has been ported to the full 3D Mars GCM. Initial results clearly show the effects of NLTE in the upper middle atmosphere. Diagnostic of seasonal mean fields and large-scale wave activity will be shown with insight into circulation patterns in the middle atmosphere. Furthermore, sensitivity tests with the resolution of the pressure and temperature grids, in which the k-coefficients are calculated upon, have been performed in the 1D RT code. Our progress on this research will be presented. Brecht is supported by NASA’s Postdoctoral Program at the Ames Research Center, administered by Oak Ridge Associated Universities through a contract with NASA.

The atmosphere of Pluto as observed by New Horizons

NASA Astrophysics Data System (ADS)

Gladstone, G. Randall; Stern, S. Alan; Ennico, Kimberly; Olkin, Catherine B.; Weaver, Harold A.; Young, Leslie A.; Summers, Michael E.; Strobel, Darrell F.; Hinson, David P.; Kammer, Joshua A.; Parker, Alex H.; Steffl, Andrew J.; Linscott, Ivan R.; Parker, Joel Wm.; Cheng, Andrew F.; Slater, David C.; Versteeg, Maarten H.; Greathouse, Thomas K.; Retherford, Kurt D.; Throop, Henry; Cunningham, Nathaniel J.; Woods, William W.; Singer, Kelsi N.; Tsang, Constantine C. C.; Schindhelm, Eric; Lisse, Carey M.; Wong, Michael L.; Yung, Yuk L.; Zhu, Xun; Curdt, Werner; Lavvas, Panayotis; Young, Eliot F.; Tyler, G. Leonard; Bagenal, F.; Grundy, W. M.; McKinnon, W. B.; Moore, J. M.; Spencer, J. R.; Andert, T.; Andrews, J.; Banks, M.; Bauer, B.; Bauman, J.; Barnouin, O. S.; Bedini, P.; Beisser, K.; Beyer, R. A.; Bhaskaran, S.; Binzel, R. P.; Birath, E.; Bird, M.; Bogan, D. J.; Bowman, A.; Bray, V. J.; Brozovic, M.; Bryan, C.; Buckley, M. R.; Buie, M. W.; Buratti, B. J.; Bushman, S. S.; Calloway, A.; Carcich, B.; Conard, S.; Conrad, C. A.; Cook, J. C.; Cruikshank, D. P.; Custodio, O. S.; Ore, C. M. Dalle; Deboy, C.; Dischner, Z. J. B.; Dumont, P.; Earle, A. M.; Elliott, H. A.; Ercol, J.; Ernst, C. M.; Finley, T.; Flanigan, S. H.; Fountain, G.; Freeze, M. J.; Green, J. L.; Guo, Y.; Hahn, M.; Hamilton, D. P.; Hamilton, S. A.; Hanley, J.; Harch, A.; Hart, H. M.; Hersman, C. B.; Hill, A.; Hill, M. E.; Holdridge, M. E.; Horanyi, M.; Howard, A. D.; Howett, C. J. A.; Jackman, C.; Jacobson, R. A.; Jennings, D. E.; Kang, H. K.; Kaufmann, D. E.; Kollmann, P.; Krimigis, S. M.; Kusnierkiewicz, D.; Lauer, T. R.; Lee, J. E.; Lindstrom, K. L.; Lunsford, A. W.; Mallder, V. A.; Martin, N.; McComas, D. J.; McNutt, R. L.; Mehoke, D.; Mehoke, T.; Melin, E. D.; Mutchler, M.; Nelson, D.; Nimmo, F.; Nunez, J. I.; Ocampo, A.; Owen, W. M.; Paetzold, M.; Page, B.; Pelletier, F.; Peterson, J.; Pinkine, N.; Piquette, M.; Porter, S. B.; Protopapa, S.; Redfern, J.; Reitsema, H. J.; Reuter, D. C.; Roberts, J. H.; Robbins, S. J.; Rogers, G.; Rose, D.; Runyon, K.; Ryschkewitsch, M. G.; Schenk, P.; Sepan, B.; Showalter, M. R.; Soluri, M.; Stanbridge, D.; Stryk, T.; Szalay, J. R.; Tapley, M.; Taylor, A.; Taylor, H.; Umurhan, O. M.; Verbiscer, A. J.; Versteeg, M. H.; Vincent, M.; Webbert, R.; Weidner, S.; Weigle, G. E.; White, O. L.; Whittenburg, K.; Williams, B. G.; Williams, K.; Williams, S.; Zangari, A. M.; Zirnstein, E.

2016-03-01

Observations made during the New Horizons flyby provide a detailed snapshot of the current state of Pluto's atmosphere. Whereas the lower atmosphere (at altitudes of less than 200 kilometers) is consistent with ground-based stellar occultations, the upper atmosphere is much colder and more compact than indicated by pre-encounter models. Molecular nitrogen (N2) dominates the atmosphere (at altitudes of less than 1800 kilometers or so), whereas methane (CH4), acetylene (C2H2), ethylene (C2H4), and ethane (C2H6) are abundant minor species and likely feed the production of an extensive haze that encompasses Pluto. The cold upper atmosphere shuts off the anticipated enhanced-Jeans, hydrodynamic-like escape of Pluto's atmosphere to space. It is unclear whether the current state of Pluto's atmosphere is representative of its average state - over seasonal or geologic time scales.

The atmosphere of Pluto as observed by New Horizons.

PubMed

Gladstone, G Randall; Stern, S Alan; Ennico, Kimberly; Olkin, Catherine B; Weaver, Harold A; Young, Leslie A; Summers, Michael E; Strobel, Darrell F; Hinson, David P; Kammer, Joshua A; Parker, Alex H; Steffl, Andrew J; Linscott, Ivan R; Parker, Joel Wm; Cheng, Andrew F; Slater, David C; Versteeg, Maarten H; Greathouse, Thomas K; Retherford, Kurt D; Throop, Henry; Cunningham, Nathaniel J; Woods, William W; Singer, Kelsi N; Tsang, Constantine C C; Schindhelm, Eric; Lisse, Carey M; Wong, Michael L; Yung, Yuk L; Zhu, Xun; Curdt, Werner; Lavvas, Panayotis; Young, Eliot F; Tyler, G Leonard

2016-03-18

Observations made during the New Horizons flyby provide a detailed snapshot of the current state of Pluto's atmosphere. Whereas the lower atmosphere (at altitudes of less than 200 kilometers) is consistent with ground-based stellar occultations, the upper atmosphere is much colder and more compact than indicated by pre-encounter models. Molecular nitrogen (N2) dominates the atmosphere (at altitudes of less than 1800 kilometers or so), whereas methane (CH4), acetylene (C2H2), ethylene (C2H4), and ethane (C2H6) are abundant minor species and likely feed the production of an extensive haze that encompasses Pluto. The cold upper atmosphere shuts off the anticipated enhanced-Jeans, hydrodynamic-like escape of Pluto's atmosphere to space. It is unclear whether the current state of Pluto's atmosphere is representative of its average state--over seasonal or geologic time scales. Copyright © 2016, American Association for the Advancement of Science.

Digital Literacy and Sustainability--A Field Study in EFL Teacher Development

ERIC Educational Resources Information Center

Allen, Christopher; Berggren, Jan

2016-01-01

This project introduces the concept of digital literacy at a practical level to a group of EFL teachers within the context of a single work place; a technologically well-resourced upper secondary school in Sweden. English teachers were provided with a theoretical and practical overview of the digital literacy concept as described by Dudeney,…

Digital Fabrication as an Instructional Technology for Supporting Upper Elementary and Middle School Science and Mathematics Education

ERIC Educational Resources Information Center

Tillman, Daniel

2012-01-01

The purpose of this three-paper manuscript dissertation was to study digital fabrication as an instructional technology for supporting elementary and middle school science and mathematics education. Article one analyzed the effects of digital fabrication activities that were designed to contextualize mathematics education at a summer mathematics…

Comparisons of planetary wave propagation to the upper atmosphere during stratospheric warming events at different QBO phases

NASA Astrophysics Data System (ADS)

Koval, Andrey V.; Gavrilov, Nikolai M.; Pogoreltsev, Alexander I.; Savenkova, Elena N.

2018-06-01

The dynamical coupling of the lower and upper atmosphere by planetary waves (PWs) is studied. Numerical simulations of planetary wave (PW) amplitudes during composite sudden stratospheric warming (SSW) events in January-February are made using a model of general circulation of the middle and upper atmosphere with initial and boundary conditions typical for the westerly and easterly phases of quasi-biennial oscillation (QBO). The changes in PW amplitudes in the middle atmosphere before, during and after SSW event for the different QBO phases are considered. Near the North Pole, the increase in the mean temperature during SSW reaches 10-30 K at altitudes 30-50 km for four pairs of the model runs with the eQBO and wQBO, which is characteristic for the sudden stratospheric warming event. Amplitudes of stationary PWs in the middle atmosphere of the Northern hemisphere may differ up to 30% during wQBO and eQBO before and during the SSW. After the SSW event SPW amplitudes are substantially larger during wQBO phase. PW refractivity indices and Eliassen-Palm flux vectors are calculated. The largest EP-fluxes in the middle atmosphere correspond to PWs with zonal wavenumber m=1. Simulated changes in PW amplitudes correspond to inhomogeneities of the global circulation, refractivity index and EP-flux produced by the changes in QBO phases. Comparisons of differences in PW characteristics and circulation between the wQBO and eQBO show that PWs could provide effective coupling mechanism and transport dynamical changes from local regions of the lower atmosphere to distant regions of the upper atmosphere of both hemispheres.

Three-dimensional dynamical and chemical modelling of the upper atmosphere

NASA Technical Reports Server (NTRS)

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

1976-01-01

Progress in coding a 3-D upper atmospheric model and in modeling the ozone perturbation resulting from the shuttle booster exhaust is reported. A time-dependent version of a 2-D model was studied and the sulfur cycle in the stratosphere was investigated. The role of meteorology in influencing stratospheric composition measurements was also studied.

Ultraviolet emissions from the upper atmospheres of the planets

NASA Technical Reports Server (NTRS)

Moos, H. W.

1981-01-01

Some recent results on planetary upper atmospheres obtained by means of orbiting ultraviolet observatories are reviewed with emphasis on Jupiter and Io torus. Consideration is given to long-term variation in Jovian Ly alpha emission, UV polar auroras on Jupiter, and UV emission from the Io torus. Requirements for UV planetary astronomy are briefly discussed.

The generalization of upper atmospheric wind and temperature based on the Voigt line shape profile.

PubMed

Zhang, Chunmin; He, Jian

2006-12-25

The principle of probing the upper atmospheric wind field, which is the Voigt profile spectral line shape, is presented for the first time. By the Fourier Transform of Voigt profile, with the Imaging Spectroscope and the Doppler effect of electromagnetic wave, the distribution and calculation formulae of the velocity field, temperature field, and pressure field of the upper atmosphere wind field are given. The probed source is the two major aurora emission lines originated from the metastable O(1S) and O(1D) at 557.7nm and 630.0nm. From computer simulation and error analysis, the Voigt profile, which is the correlation of the Gaussian profile and Lorentzian profile, is closest to the actual airglow emission lines.

Nitrogen Chemistry in Titan's Upper Atmosphere

NASA Technical Reports Server (NTRS)

McKay, Christopher P.; Cuzzi, Jeffrey (Technical Monitor)

1996-01-01

In Titan's upper atmosphere N2 is dissociated to N by solar UV and high energy electrons. This flux of N provides for interesting organic chemistry in the lower atmosphere of Titan. Previously the main pathway for the loss of this N was thought to be the formation of HCN, followed by diffusion of this HCN to lower altitudes leading ultimately to condensation. However, recent laboratory simulations of organic chemistry in Titan's atmosphere suggest that formation of the organic haze may be an important sink for atmospheric N. Because estimates of the eddy diffusion profile on Titan have been based on the HCN profile, inclusion of this additional sink for N will affect estimates for all transport processes in Titan's atmosphere. This and other implications of this sink for the N balance on Titan are considered.

High-resolution optical measurements of atmospheric winds from space. I - Lower atmosphere molecular absorption

NASA Technical Reports Server (NTRS)

Hays, P. B.

1982-01-01

A high-resolution spectroscopic technique, analogous to that used in the thermosphere to measure the vector wind fields in the upper troposphere and stratosphere, is described which uses narrow features in the spectrum of light scattered from the earth's lower atmosphere to provide Doppler information on atmospheric scattering and absorption. It is demonstrated that vector winds can be measured from a satellite throughout the lower atmosphere, using a multiple-etalon Fabry-Perot interferometer of modest aperture. It is found that molecular oxygen and water vapor absorption lines in the spectrum of sunlight scattered by the atmosphere are Doppler-shifted by the line of sight wind, so that they may be used to monitor the global wind systems in the upper troposphere and stratosphere.

Venus Atmospheric Maneuverable Platform (VAMP)

NASA Astrophysics Data System (ADS)

Shapiro Griffin, Kristen L.; Sokol, D.; Dailey, D.; Lee, G.; Polidan, R.

2013-10-01

We have explored a possible new approach to Venus upper atmosphere exploration by applying Northrop Grumman (non-NASA) development programs to the challenges associated with Venus upper atmosphere science missions. Our concept is a low ballistic coefficient (<50 Pa), semi-buoyant aircraft that deploys prior to entering the Venus atmosphere, enters the atmosphere without an aeroshell, and provides a long-lived (months to years), maneuverable vehicle capable of carrying science payloads to explore the Venus upper atmosphere. In this presentation we report results from our ongoing study and plans for future analyses and prototyping. We discuss the overall mission architecture and concept of operations from launch through Venus arrival, orbit, entry, and atmospheric science operations. We present a strawman concept of VAMP, including ballistic coefficient, planform area, percent buoyancy, inflation gas, wing span, vehicle mass, power supply, propulsion, materials considerations, structural elements, subsystems, and packaging. The interaction between the VAMP vehicle and the supporting orbiter will also be discussed. In this context, we specifically focus upon four key factors impacting the design and performance of VAMP: 1. Feasibility of and options for the deployment of the vehicle in space 2. Entry into the Venus atmosphere, including descent profile, heat rate, total heat load, stagnation temperature, control, and entry into level flight 3. Characteristics of flight operations and performance in the Venus atmosphere: altitude range, latitude and longitude access, day/night performance, aircraft performance (aerodynamics, power required vs. power available, propulsion, speed, percent buoyancy), performance sensitivity to payload weight 4. Science payload accommodation, constraints, and opportunities We discuss interdependencies of the above factors and the manner in which the VAMP strawman’s characteristics affect the CONOPs and the science objectives. We show how these factors provide constraints as well as enable opportunities for novel long duration scientific studies of the Venus upper atmosphere that support VEXAG goals 2 and 3.

New Discoveries Resulted from Lidar Investigation of Middle and Upper Atmosphere Temperature, Composition, Chemistry and Dynamics at McMurdo, Antarctica

NASA Astrophysics Data System (ADS)

Chu, X.; Yu, Z.; Fong, W.; Chen, C.; Huang, W.; Lu, X.; Gardner, C. S.; McDonald, A.; Fuller-Rowell, T. J.; Vadas, S.

2013-12-01

The scientific motivation to explore the neutral properties of the polar middle and upper atmosphere is compelling. Human-induced changes in the Earth's climate system are one of the most challenging social and scientific issues in this century. Besides monitoring climate change, to fully explore neutral-ion coupling in the critical region between 100 and 200 km is an objective of highest priority for the upper atmosphere science community. Meteorological sources of wave energy from the lower atmosphere are responsible for producing significant variability in the upper atmosphere. Energetic particles and fields originating from the magnetosphere regularly alter the state of the ionosphere. These influences converge through the tight coupling between the ionosphere plasma and neutral thermosphere gas in the space-atmosphere interaction region (SAIR). Unfortunately measurements of the neutral thermosphere are woefully incomplete and in critical need to advance our understanding of and ability to predict the SAIR. Lidar measurements of neutral thermospheric winds, temperatures and species can enable these explorations. To help address these issues, in December 2010 we deployed an Fe Boltzmann temperature lidar to McMurdo (77.8S, 166.7E), Antarctica via collaboration between the United States Antarctic Program and Antarctica New Zealand. Since then an extensive dataset (~3000 h) has been collected by this lidar during its first 32 months of operation, leading to several important new discoveries. The McMurdo lidar campaign will continue for another five years to acquiring long-term datasets for polar geospace research. In this paper we provide a comprehensive overview of the lidar campaign and scientific results, emphasizing several new discoveries in the polar middle and upper atmosphere research. In particular, the lidar has detected neutral Fe layers reaching 170 km in altitude, and derived neutral temperature from 30 to 170 km for the first time in the world. Such discoveries may have opened the new door to observing the neutral thermosphere with ground-based instruments. Extreme Fe events in summer were observed and understood as the interesting interactions among the meteoric metal atoms, sub-visible ice particles and energetic particles during aurora precipitation. Furthermore, the McMurdo middle and upper atmosphere is found to be very dynamical, especially in winter when inertia-gravity waves and eastward propagating planetary waves are predominant in the mesosphere and lower thermosphere and in the stratosphere, respectively. Despite small amplitudes below 100 km, the diurnal and semidiurnal tidal amplitudes exhibit fast growth from 100 to 110 km depending on the geomagnetic activities. These observations pose great challenges to our understanding of the Earth's upper atmosphere but also provide excellent opportunities to exploring how the electrodynamics and neutral dynamics work together at this high southern latitude to produce many intriguing geophysical phenomena.

The microwave limb sounder for the Upper Atmosphere Research Satellite

NASA Technical Reports Server (NTRS)

Waters, J. W.; Peckham, G. E.; Suttie, R. A.; Curtis, P. D.; Maddison, B. J.; Harwood, R. S.

1988-01-01

The Microwave Limb Sounder was designed to map the concentrations of trace gases from the stratosphere to the lower thermosphere, to improve understanding of the photochemical reactions which take place in this part of the atmosphere. The instrument will measure the intensity of thermal radiation from molecules in the atmosphere at frequencies corresponding to rotational absorption bands of chlorine monoxide, ozone, and water vapor. Molecular concentration profiles will be determined over a height range of 15 to 80 km (20 to 45 km for C10). The 57 deg inclination orbit proposed for the Upper Atmosphere Research Satellite will allow global coverage.

Atmospheric Photochemistry

NASA Technical Reports Server (NTRS)

Massey, Harrie; Potter, A. E.

1961-01-01

The upper atmosphere offers a vast photochemical laboratory free from solid surfaces, so all reactions take place in the gaseous phase. At 30 km altitude the pressure has fallen to about one-hundredth of that at ground level, and we shall, rather arbitrarily, regard the upper atmosphere as beginning at that height. By a little less than 100 km the pressure has fallen to 10(exp -3) mm Hg and is decreasing by a power of ten for every 15 km increase in altitude. Essentially we are concerned then with the photochemistry of a nitrogen-oxygen mixture under low-pressure conditions in which photo-ionization, as well as photodissociation, plays an important part. Account must also be taken of the presence of rare constituents, such as water vapour and its decomposition products, including particularly hydroxyl, oxides of carbon, methane and, strangely enough, sodium, lithium and calcium. Many curious and unfamiliar reactions occur in the upper atmosphere. Some of them are luminescent, causing the atmosphere to emit a dim light called the airglow. Others, between gaseous ions and neutral molecules, are almost a complete mystery at this time. Similar interesting phenomena must occur in other planetary atmospheres, and they might be predicted if sufficient chemical information were available.

Middle Atmosphere Program. Handbook for MAP. Volume 13: Ground-based Techniques

NASA Technical Reports Server (NTRS)

Vincent, R. A. (Editor)

1984-01-01

Topics of activities in the middle Atmosphere program covered include: lidar systems of aerosol studies; mesosphere temperature; upper atmosphere temperatures and winds; D region electron densities; nitrogen oxides; atmospheric composition and structure; and optical sounding of ozone.

Characteristics of atmospheric gravity waves observed using the MU (Middle and Upper atmosphere) radar and GPS (Global Positioning System) radio occultation.

PubMed

Tsuda, Toshitaka

2014-01-01

The wind velocity and temperature profiles observed in the middle atmosphere (altitude: 10-100 km) show perturbations resulting from superposition of various atmospheric waves, including atmospheric gravity waves. Atmospheric gravity waves are known to play an important role in determining the general circulation in the middle atmosphere by dynamical stresses caused by gravity wave breaking. In this paper, we summarize the characteristics of atmospheric gravity waves observed using the middle and upper atmosphere (MU) radar in Japan, as well as novel satellite data obtained from global positioning system radio occultation (GPS RO) measurements. In particular, we focus on the behavior of gravity waves in the mesosphere (50-90 km), where considerable gravity wave attenuation occurs. We also report on the global distribution of gravity wave activity in the stratosphere (10-50 km), highlighting various excitation mechanisms such as orographic effects, convection in the tropics, meteorological disturbances, the subtropical jet and the polar night jet.

Characteristics of atmospheric gravity waves observed using the MU (Middle and Upper atmosphere) radar and GPS (Global Positioning System) radio occultation

PubMed Central

TSUDA, Toshitaka

2014-01-01

The wind velocity and temperature profiles observed in the middle atmosphere (altitude: 10–100 km) show perturbations resulting from superposition of various atmospheric waves, including atmospheric gravity waves. Atmospheric gravity waves are known to play an important role in determining the general circulation in the middle atmosphere by dynamical stresses caused by gravity wave breaking. In this paper, we summarize the characteristics of atmospheric gravity waves observed using the middle and upper atmosphere (MU) radar in Japan, as well as novel satellite data obtained from global positioning system radio occultation (GPS RO) measurements. In particular, we focus on the behavior of gravity waves in the mesosphere (50–90 km), where considerable gravity wave attenuation occurs. We also report on the global distribution of gravity wave activity in the stratosphere (10–50 km), highlighting various excitation mechanisms such as orographic effects, convection in the tropics, meteorological disturbances, the subtropical jet and the polar night jet. PMID:24492645

Whole Atmosphere Simulation of Anthropogenic Climate Change

NASA Astrophysics Data System (ADS)

Solomon, Stanley C.; Liu, Han-Li; Marsh, Daniel R.; McInerney, Joseph M.; Qian, Liying; Vitt, Francis M.

2018-02-01

We simulated anthropogenic global change through the entire atmosphere, including the thermosphere and ionosphere, using the Whole Atmosphere Community Climate Model-eXtended. The basic result was that even as the lower atmosphere gradually warms, the upper atmosphere rapidly cools. The simulations employed constant low solar activity conditions, to remove the effects of variable solar and geomagnetic activity. Global mean annual mean temperature increased at a rate of +0.2 K/decade at the surface and +0.4 K/decade in the upper troposphere but decreased by about -1 K/decade in the stratosphere-mesosphere and -2.8 K/decade in the thermosphere. Near the mesopause, temperature decreases were small compared to the interannual variation, so trends in that region are uncertain. Results were similar to previous modeling confined to specific atmospheric levels and compared favorably with available measurements. These simulations demonstrate the ability of a single comprehensive numerical model to characterize global change throughout the atmosphere.

Digital Storytelling: A Tool for Identifying and Developing Cultural Competence with Preservice Teachers in an Introduction to Middle Level Education Course

ERIC Educational Resources Information Center

Ruppert, Nancy; Adcock, Lee T.; Crave, Jared

2017-01-01

Using five themes associated with a diversity intensive undergraduate course, preservice teachers in an upper level introduction to middle grade course described their knowledge of cultural competence using digital storytelling as the tool. Findings suggest digital storytelling provides a tool to explore and describe how cultural competence is…

H20 and CH4 abundances under non-LTE conditions from MIPAS upper atmosphere measurements.

NASA Astrophysics Data System (ADS)

Koukouli, M. E.; Imk-Iaa Mipas/Envisat Team

Vertical profiles of water vapour and methane have been retrieved from measurements of the Earth's Upper Atmosphere made by the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) on board the polar orbiting ENVISAT satellite. The spectral range targeted is 685-2410 cm-1 (4.1-14.6 μm) and the retrieval altitude range is ˜25-80 km. The Generic RAdiative traNsfer AnD non-LTE population Algorithm (GRANADA), jointly developed by IAA and IMK, has been used to analyse two days' worth of upper atmosphere orbits, from July 2002 and June 2003. The vertical profiles retrieved are compared and calibrated against other known water vapour experiments (e.g. HALOE) in the corresponding vertical and spacial co-locations. Global three-dimensional maps are also presented and validated against modelling results (e.g. Garcia and Solomon). The total hydrogen content of the Earth's middle atmosphere will also be investigated as means of identifying possible sinks or sources in the water vapour and methane day-night variability. A comprehensive systematic error analysis will complement the presentation of the results.

Incorporating Planetary-Scale Waves Into the VTGCM: Understanding the Waves Impact on the Upper Atmosphere of Venus.

NASA Technical Reports Server (NTRS)

Brecht, A. S.; Bougher, S. W.; Shields, D.; Liu, H.

2017-01-01

Venus has proven to have a very dynamic upper atmosphere. The upper atmosphere of Venus has been observed for many decades by multiple means of observation (e.g. ground-based, orbiters, probes, fly-by missions going to other planets). As of late, the European Space Agency Venus Express (VEX) orbiter has been a main observer of the Venusian atmosphere. Specifically, observations of Venus' O2 IR nightglow emission have been presented to show its variability. Nightglow emission is directly connected to Venus' circulation and is utilized as a tracer for the atmospheric global wind system. More recent observations are adding and augmenting temperature and density (e.g. CO, CO2, SO2) datasets. These additional datasets provide a means to begin analyzing the variability and study the potential drivers of the variability. A commonly discussed driver of variability is wave deposition. Evidence of waves has been observed, but these waves have not been completely analyzed to understand how and where they are important. A way to interpret the observations and test potential drivers is by utilizing numerical models.

Physical Mechanisms Controlling Upper Tropospheric Water Vapor as Revealed by MLS Data from UARS

NASA Technical Reports Server (NTRS)

Newell, Reginald E.; Douglass, Anne (Technical Monitor)

2002-01-01

The third year and final report on the physical mechanisms controlling upper tropospheric water vapor revealed by the Microwave Limb Sounder (MLS) on the Upper Atmosphere Research Satellite (UARS) is presented.

Winds and Waves (4 Min - 11 Yrs) in the Upper Middle Atmosphere (60-110 Km) at Saskatoon, Canada (52 Deg N, 107 Deg W): MF Radar (2.2 Mhz) Soundings 1973 - 1983

NASA Technical Reports Server (NTRS)

Manson, A. H.; Meek, C. E.; Gregory, J. B.

1984-01-01

Examples of gravity waves (GW), tides, planetary waves (PW), and circulation effects in the upper middle atmosphere are presented. Energy densities of GW, tides, and PW are compared. Fourier and spectral analyses are applied to the data.

Enhancements in lower stratospheric CH3CN observed by the upper atmosphere research Sattellite Microwave Limb Sounder following boreal forest fires

NASA Technical Reports Server (NTRS)

Livesey, N. J.; Fromm, M. D.; Waters, J. W.; Manney, G. L.; Santee, M. L.; Read, W. G.

2004-01-01

On 25 August 1992, the Microwave Limb Sounder (MLS) on the Upper Atmosphere Research Satellite observed a significant enhancement in the abundance of lower stratospheric methyl cyanide (CH3CN) at 100??hPa (16??km altitude) in a small region off the east coast of Florida.

Detection of CO and HCN in Pluto's atmosphere with ALMA

NASA Astrophysics Data System (ADS)

Lellouch, E.; Gurwell, M.; Butler, B.; Fouchet, T.; Lavvas, P.; Strobel, D. F.; Sicardy, B.; Moullet, A.; Moreno, R.; Bockelée-Morvan, D.; Biver, N.; Young, L.; Lis, D.; Stansberry, J.; Stern, A.; Weaver, H.; Young, E.; Zhu, X.; Boissier, J.

2017-04-01

Observations of the Pluto-Charon system, acquired with the ALMA interferometer on June 12-13, 2015, have led to the detection of the CO(3-2) and HCN(4-3) rotational transitions from Pluto (including the hyperfine structure of HCN), providing a strong confirmation of the presence of CO, and the first observation of HCN in Pluto's atmosphere. The CO and HCN lines probe Pluto's atmosphere up to ∼450 km and ∼900 km altitude, respectively, with a large contribution due to limb emission. The CO detection yields (i) a much improved determination of the CO mole fraction, as 515 ± 40 ppm for a 12 μbar surface pressure (ii) strong constraints on Pluto's mean atmospheric dayside temperature profile over ∼50-400 km, with clear evidence for a well-marked temperature decrease (i.e., mesosphere) above the 30-50 km stratopause and a best-determined temperature of 70 ± 2 K at 300 km, somewhat lower than previously estimated from stellar occultations (81 ± 6 K), and in agreement with recent inferences from New Horizons / Alice solar occultation data. The HCN line shape implies a high abundance of this species in the upper atmosphere, with a mole fraction >1.5 × 10-5 above 450 km and a value of 4 × 10-5 near 800 km. Assuming HCN at saturation, this would require a warm (>92 K) upper atmosphere layer; while this is not ruled out by the CO emission, it is inconsistent with the Alice-measured CH4 and N2 line-of-sight column densities. Taken together, the large HCN abundance and the cold upper atmosphere imply supersaturation of HCN to a degree (7-8 orders of magnitude) hitherto unseen in planetary atmospheres, probably due to a lack of condensation nuclei above the haze region and the slow kinetics of condensation at the low pressure and temperature conditions of Pluto's upper atmosphere. HCN is also present in the bottom ∼100 km of the atmosphere, with a 10-8-10-7 mole fraction; this implies either HCN saturation or undersaturation there, depending on the precise stratopause temperature. The HCN column is (1.6 ± 0.4)× 1014 cm-2 , suggesting a surface-referred vertically-integrated net production rate of ∼2 × 107 cm-2 s-1. Although HCN rotational line cooling affects Pluto's atmosphere heat budget, the amounts determined in this study are insufficient to explain the well-marked mesosphere and upper atmosphere's ∼70 K temperature, which if controlled by HCN cooling would require HCN mole fractions of (3-7) ×10-4 over 400-800 km. We finally report an upper limit on the HC3N column density (<2 × 1013 cm-2) and on the HC15N / HC14N ratio (<1/125).

Wideband Spectroscopy: The Design and Implementation of a 3 GHz Bandwidth, 8192 Channel, Polyphase Digital Spectrometer

NASA Technical Reports Server (NTRS)

Monroe, Ryan M.

2011-01-01

A family of state-of-the-art digital Fourier transform spectrometers has been developed, with a combination of high bandwidth and fine resolution unavailable elsewhere. Analog signals consisting of radiation emitted by constituents in planetary atmospheres or galactic sources are downconverted and subsequently digitized by a pair of interleaved Analog-to-Digital Converters, (ADC). This 6 Gsps (giga-sample per second) digital representation of the analog signal is then processed through an FPGA-based streaming Fast Fourier Transform (FFT), the key development described below. Digital spectrometers have many advantages over previously used analog spectrometers, especially in terms of accuracy and resolution, both of which are particularly important for the type of scientific questions to be addressed with next-generation radiometers. the implementation, results and underlying math for this spectrometer, as well as, potential for future extension to even higher bandwidth, resolution and channel orthogonality, needed to support proposed future advanced atmospheric science and radioastronomy, are discussed.

Wideband Spectroscopy: The Design and Implementation of a 3 GHz, 2048 Channel Digital Spectrometer

NASA Technical Reports Server (NTRS)

Monroe, Ryan M.

2011-01-01

A state-of-the-art digital Fourier Transform spectrometer has been developed, with a combination of high bandwidth and fine resolution unavailable elsewhere. Analog signals consisting of radiation emitted by constituents in planetary atmospheres or galactic sources are downconverted and subsequently digitized by a pair of interleaved Analog-to-Digital Converters (ADC). This 6 Gsps (giga sample per second) digital representation of the analog signal is then processed through an FPGA-based streaming Fast Fourier Transform (FFT), the key development described below. Digital spectrometers have many advantages over previously used analog spectrometers, especially in terms of accuracy and resolution, both of which are particularly important for the type of scientific questions to be addressed with next-generation radiometers. The implementation, results and underlying math for this spectrometer, as well as potential for future extension to even higher bandwidth, resolution and channel orthogonality, needed to support proposed future advanced atmospheric science and radioastronomy, are discussed.

The upper atmosphere and ionosphere of Mars

NASA Technical Reports Server (NTRS)

Brace, Larry H.

1992-01-01

The topics discussed include the following: the dynamic atmosphere of Mars; possible similarities with Earth and Venus; the atmosphere and ionosphere of Mars; solar wind interactions; future approved missions; and possible future mission.

Land cover mapping of the upper Kuskokwim Resource Managment Area using LANDSAT and a digital data base approach

USGS Publications Warehouse

Markon, Carl J.

1988-01-01

Digital land cover and terrain data for the Upper Kuskokwim Resource Hanagement Area (UKRMA) were produced by the U.S. Geological Survey, Earth Resources Observation Systems Field Office, Anchorage, Alaska for the Bureau of Land Management. These and other environmental data, were incorporated into a digital data base to assist in the management and planning of the UKRMA. The digital data base includes land cover classifications, elevation, slope, and aspect data centering on the UKRMA boundaries. The data are stored on computer compatible tapes at a 50-m pixel size. Additional digital data in the data base include: (a) summer and winter Landsat multispectral scanner (MSS) data registered to a 50-m Universal Transverse Mercator grid; (b) elevation, slope, aspect, and solar illumination data; (c) soils and surficial geology; and (e) study area boundary. The classification of Landsat MSS data resulted in seven major classes and 24 subclasses. Major classes include: forest, shrubland, dwarf scrub, herbaceous, barren, water, and other. The final data base will be used by resource personnel for management and planning within the UKRMA.

Future monitoring of charged particle energy deposition into the upper atmosphere and comments on possible relationships between atmospheric phenomena and solar and/or geomagnetic activity

NASA Technical Reports Server (NTRS)

Williams, D. J.; Grubb, R. N.; Evans, D. S.; Sauer, H. H.

1974-01-01

The charged particle observations proposed for the new low altitude weather satellites, TIROS-N, are described that will provide the capability of routine monitoring of the instantaneous total energy deposition into the upper atmosphere by the precipitation of charged particles from higher altitudes. Estimates are given to assess the potential importance of this type of energy deposition. Discussion and examples are presented illustrating the importance in distinguishing between solar and geomagnetic activity as possible causative sources.

The high-resolution Doppler imager on the Upper Atmosphere Research Satellite

NASA Technical Reports Server (NTRS)

Hays, Paul B.; Abreu, Vincent J.; Dobbs, Michael E.; Gell, David A.; Grassl, Heinz J.; Skinner, Wilbert R.

1993-01-01

The high-resolution Doppler imager (HRDI) on the Upper Atmosphere Research Satellite is a triple-etalon Fabry-Perot interferometer designed to measure winds in the stratosphere, mesosphere, and lower thermosphere. Winds are determined by measuring the Doppler shifts of rotational lines of the O2 atmospheric band, which are observed in emission in the mesosphere and lower thermosphere and in absorption in the stratosphere. The interferometer has high resolution (0.05/cm), good offhand rejection, aud excellent stability. This paper provides details of the design and capabilities of the HRDI instrument.

Aircraft Configured for Flight in an Atmosphere Having Low Density

NASA Technical Reports Server (NTRS)

Teter, Jr., John E. (Inventor); Croom, Mark A. (Inventor); Smith, Stephen C. (Inventor); Gelhausen, Paul A. (Inventor); Hunter, Craig A. (Inventor); Riddick, Steven E. (Inventor); Guynn, Mark D. (Inventor); Paddock, David A. (Inventor)

2012-01-01

An aircraft is configured for flight in an atmosphere having a low density. The aircraft includes a fuselage, a pair of wings, and a rear stabilizer. The pair of wings extends from the fuselage in opposition to one another. The rear stabilizer extends from the fuselage in spaced relationship to the pair of wings. The fuselage, the wings, and the rear stabilizer each present an upper surface opposing a lower surface. The upper and lower surfaces have X, Y, and Z coordinates that are configured for flight in an atmosphere having low density.

A transceiver module of the Mu radar

NASA Technical Reports Server (NTRS)

Kato, S.; Ogawa, T.; Tsuda, T.; Sato, T.; Kimura, I.; Fukao, S.

1983-01-01

The transceiver (TR) module of a middle and upper atmospheric radar is described. The TR module used in the radar is mainly composed of two units: a mixer (MIX unit) and a power amplifier (PA unit). The former generates the RF wave for transmission and converts the received echo to the IF signal. A 41.5-MHz local signal fed to mixers passes through a digitally controlled 8-bit phase shifter which can change its value up to 1,000 times in a second, so that the MU radar has the ability to steer its antenna direction quickly and flexibly. The MIX unit also contains a buffer amplifier and a gate for the transmitting signal and preamplifier for the received one whose noise figure is less than 5 dB. The PA unit amplifies the RF signal supplied from the MIX unit up to 63.7 dBm (2350 W), and feeds it to the crossed Yagi antenna.

Digital solar edge tracker for the Halogen Occultation Experiment

NASA Technical Reports Server (NTRS)

Mauldin, L. E., III; Moore, A. S.; Stump, C. W.; Mayo, L. S.

1987-01-01

The optical and electronic design of the Halogen Occultation Experiment (Haloe) elevation sun sensor is described. The Haloe instrument is a gas-correlation radiometer now being developed at NASA Langley for the Upper Atmosphere Research Satellite. The system uses a Galilean telescope to form a solar image on a linear silicon photodiode array. The array is a self-scanned monolithic CCD. The addresses of both solar edges imaged on the array are used by the control/pointing system to scan the Haloe science instantaneous field of view (IFOV) across the vertical solar diameter during instrument calibration and then to maintain the science IFOV 4 arcmin below the top edge during the science data occultation event. Vertical resolution of 16 arcsec and a radiometric dynamic range of 100 are achieved at the 700-nm operating wavelength. The design provides for loss of individual photodiode elements without loss of angular tracking capability.

Age estimation by canines' pulp/tooth ratio in an Iranian population using digital panoramic radiography.

PubMed

Dehghani, Mahdieh; Shadkam, Elaheh; Ahrari, Farzaneh; Dehghani, Mahboobe

2018-04-01

Age estimation in adults is an important issue in forensic science. This study aimed to estimate the chronological age of Iranians by means of pulp/tooth area ratio (AR) of canines in digital panoramic radiographs. The sample consisted of panoramic radiographs of 271 male and female subjects aged 16-64 years. The pulp/tooth area ratio (AR) of upper and lower canines was calculated by AutoCAD software. Data were subjected to correlation and regression analysis. There was a significant and inverse correlation between age and pulp/tooth area ratio of upper and lower canines (r=-0.794 for upper canine and r=-0.282 for lower canine; p-value<0.001). Linear regression equations were derived separately for upper, lower and both canines. The mean difference between actual and estimated age using upper canine was 6.07±1.7. The results showed that the pulp/tooth area ratios of canines are a reliable method for age estimation in Iranians. The pulp/tooth area ratio of upper canine was better correlated with chronological age than that of lower canine. Copyright © 2018 Elsevier B.V. All rights reserved.

Toward a New Capability for Upper Atmospheric Research using Atomic Oxygen Lidar

NASA Astrophysics Data System (ADS)

Clemmons, J. H.; Steinvurzel, P.; Mu, X.; Beck, S. M.; Lotshaw, W. T.; Rose, T. S.; Hecht, J. H.; Westberg, K. R.; Larsen, M. F.; Chu, X.; Fritts, D. C.

2017-12-01

Progress on development of a lidar system for probing the upper atmosphere based on atomic oxygen resonance is presented and discussed. The promise of a fully-developed atomic oxygen lidar system, which must be based in space to measure the upper atmosphere, for yielding comprehensive new insights is discussed in terms of its potential to deliver global, height-resolved measurements of winds, temperature, and density at a high cadence. An overview of the system is given, and its measurement principles are described, including its use of 1) a two-photon transition to keep the optical depth low; 2) laser tuning to provide the Doppler information needed to measure winds; and 3) laser tuning to provide a Boltzmann temperature measurement. The current development status is presented with a focus on what has been done to demonstrate capability in the laboratory and its evolution to a funded sounding rocket investigation designed to make measurements of three-dimensional turbulence in the upper mesosphere and lower thermosphere.

NASA’s MAVEN Mission Observes Ups and Downs of Water Escape from Mars

NASA Image and Video Library

2017-12-08

After investigating the upper atmosphere of the Red Planet for a full Martian year, NASA’s MAVEN mission has determined that the escaping water does not always go gently into space. Sophisticated measurements made by a suite of instruments on the Mars Atmosphere and Volatile Evolution, or MAVEN, spacecraft revealed the ups and downs of hydrogen escape – and therefore water loss. The escape rate peaked when Mars was at its closest point to the sun and dropped off when the planet was farthest from the sun. The rate of loss varied dramatically overall, with 10 times more hydrogen escaping at the maximum. “MAVEN is giving us unprecedented detail about hydrogen escape from the upper atmosphere of Mars, and this is crucial for helping us figure out the total amount of water lost over billions of years,” said Ali Rahmati, a MAVEN team member at the University of California at Berkeley who analyzed data from two of the spacecraft’s instruments. Hydrogen in Mars’ upper atmosphere comes from water vapor in the lower atmosphere. An atmospheric water molecule can be broken apart by sunlight, releasing the two hydrogen atoms from the oxygen atom that they had been bound to. Several processes at work in Mars’ upper atmosphere may then act on the hydrogen, leading to its escape. Read more: go.nasa.gov/2dAgAV4 NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

Venus Atmospheric Maneuverable Platform (VAMP)

NASA Astrophysics Data System (ADS)

Polidan, R.; Lee, G.; Sokol, D.; Griffin, K.; Bolisay, L.; Barnes, N.

2014-04-01

Over the past years we have explored a possible new approach to Venus upper atmosphere exploration by applying recent Northrop Grumman (non-NASA) development programs to the challenges associated with Venus upper atmosphere science missions. Our concept is a low ballistic coefficient (<50 Pa), semibuoyant aircraft that deploys prior to entering the Venus atmosphere, enters the Venus atmosphere without an aeroshell, and provides a long-lived (months to years), maneuverable vehicle capable of carrying science payloads to explore the Venus upper atmosphere. VAMP targets the global Venus atmosphere between 55 and 70 km altitude and would be a platform to address VEXAG goals I.A, I.B, and I.C. We will discuss the overall mission architecture and concept of operations from launch through Venus arrival, orbit, entry, and atmospheric science operations. We will present a strawman concept of VAMP, including ballistic coefficient, planform area, percent buoyancy, inflation gas, wing span, vehicle mass, power supply, propulsion, materials considerations, structural elements, subsystems, and packaging. The interaction between the VAMP vehicle and the supporting orbiter will also be discussed. In this context, we will specifically focus upon four key factors impacting the design and performance of VAMP: 1. Science payload accommodation, constraints, and opportunities 2. Characteristics of flight operations and performance in the Venus atmosphere: altitude range, latitude and longitude access, day/night performance, aircraft performance, performance sensitivity to payload weight 3. Feasibility of and options for the deployment of the vehicle in space 4. Entry into the Venus atmosphere, including descent profile, heat rate, total heat load, stagnation temperature, control, and entry into level flight We will discuss interdependencies of the above factors and the manner in which the VAMP strawman's characteristics affect the CONOPs and the science objectives. We will show how the these factors provide constraints as well as enable opportunities for novel long duration scientific studies of the Venus upper atmosphere that support VEXAG goals I.A, I.B, and I.C.. We will also discuss how the VAMP platform itself can facilitate some of these science measurements.

Digital amateur observations of Venus at 0.9μm

NASA Astrophysics Data System (ADS)

Kardasis, E.

2017-09-01

Venus atmosphere is extremely dynamic, though it is very difficult to observe any features on it in the visible and even in the near-IR range. Digital observations with planetary cameras in recent years routinely produce high-quality images, especially in the near-infrared (0.7-1μm), since IR wavelengths are less influenced by Earth's atmosphere and Venus's atmosphere is partially transparent in this spectral region. Continuous observations over a few hours may track dark atmospheric features in the dayside and determine their motion. In this work we will present such observations and some dark-feature motion measurements at 0.9μm. Ground-based observations at this wavelength are rare and are complementary to in situ observations by JAXA's Akatsuki orbiter, that studies the atmospheric dynamics of Venus also in this band with the IR1 camera.

MAVEN Contamination Venting and Outgassing Analysis

NASA Technical Reports Server (NTRS)

Petro, Elaine M.; Hughes, David W.; Secunda, Mark S.; Chen, Philip T.; Morrissey, James R.; Riegle, Catherine A.

2014-01-01

Mars Atmosphere and Volatile EvolutioN (MAVEN) is the first mission to focus its study on the Mars upper atmosphere. MAVEN will study the evolution of the Mars atmosphere and climate, by examining the conduit through which the atmosphere has to pass as it is lost to the upper atmosphere. An analysis was performed for the MAVEN mission to address two distinct concerns. The first goal of the analysis was to perform an outgassing study to determine where species outgassed from spacecraft materials would redistribute to and how much of the released material might accumulate on sensitive surfaces. The second portion of the analysis serves to predict what effect, if any, Mars atmospheric gases trapped within the spacecraft could have on instrument measurements when re-released through vents. The re-release of atmospheric gases is of interest to this mission because vented gases from a higher pressure spacecraft interior could bias instrument measurements of the Mars atmosphere depending on the flow rates and directions.

The Latest on the Venus Thermospheric General Circulation Model: Capabilities and Simulations

NASA Technical Reports Server (NTRS)

Brecht, A. S.; Bougher, S. W.; Parkinson, C. D.

2017-01-01

Venus has a complex and dynamic upper atmosphere. This has been observed many times by ground-based, orbiters, probes, and fly-by missions going to other planets. Two over-arching questions are generally asked when examining the Venus upper atmosphere: (1) what creates the complex structure in the atmosphere, and (2) what drives the varying dynamics. A great way to interpret and connect observations to address these questions utilizes numerical modeling; and in the case of the middle and upper atmosphere (above the cloud tops), a 3D hydrodynamic numerical model called the Venus Thermospheric General Circulation Model (VTGCM) can be used. The VTGCM can produce climatological averages of key features in comparison to observations (i.e. nightside temperature, O2 IR nightglow emission). More recently, the VTGCM has been expanded to include new chemical constituents and airglow emissions, as well as new parameterizations to address waves and their impact on the varying global circulation and corresponding airglow distributions.

The Upgraded European Digital Upper Atmosphere Server: new DIAS products for the high latitude ionosphere, the topside ionosphere and the plasmasphere

NASA Astrophysics Data System (ADS)

Belehaki, Anna; Kutiev, Ivan; Zolesi, Bruno; Tsagouri, Ioanna; Dialetis, Dimitris; Marinov, Pencho; Fidanova, Stefka; Cander, Lili; Pietrella, Marco; Tziotziou, Kostas; Lykiardopoulos, Angelos

2013-04-01

Knowledge of the state of the upper atmosphere, and in particular its ionized part, is very important in several applications affected by space weather, especially the communications and navigation systems that rely on radio transmission. To better classify the ionosphere and forecast its disturbances over Europe, a data and model infrastructure platform called the European Digital Upper Atmosphere Server (DIAS) has been established in the National Observatory of Athens by a European consortium formed around eight ionospheric stations, and funded by the European Commission. The DIAS system operates since 2006 and the basic products that are delivered are real-time and historical ionograms, frequency plots and maps of the ionosphere on the foF2, M(3000)F2, MUF and bottomside electron density, as well as long term and short term forecasting up to 24 hour ahead. The DIAS system supports more than 500 subscribed users, including telecommunication companies, satellite operators, space agencies, radio amateurs, research organizations and the space weather scientific community. In 2012 the system has been upgraded, in close collaboration between the National Observatory of Athens, the Istituto Nazionale di Geofisica e Vulcanologia and the Bulgarian Academy of Sciences, with funding from the ESA/SSA Programme. The first group of new products results from the implementation of the TaD model (Topside Sounder Model assisted by Digisonde) that makes possible the generation of maps of the electron density at heights up to GNSS orbits, and of TEC and partial TEC maps (topside and plasmaspheric) over Europe. The TaD is based on the simple empirical functions for the transition height, the topside electron density scale height and their ratio, based on the Alouette/ISIS database, and models separately the oxygen, hydrogen and helium ions density profiles. The model takes as input the plasma characteristics at the height of maximum electron concentration that are provided in real-time by the DIAS Digisondes. To further improve its accuracy, we adjust the modeled TEC parameter with the GNSS-TEC parameter calculated at the Digisondes location. This adjustment forces the model to correctly reproduce the topside scale height, even in cases when the scale height at hmF2 is not available. This adjustment is very important for the application of TaD in an operational environment. The second group of new products consists of long term prediction and of nowcasting maps of the foF2 parameter that cover the whole European region - including Scandinavia. Long term prediction maps have been extended to 80 deg N applying the CCIR coefficients for the region above 65 deg N, while from 32 to 60 deg N we continue to apply SIRM (Simplified Ionospheric Regional Model), as in the case of middle latitude maps that are released routinely by the DIAS system. Between 60 and 65 deg N there is a buffer zone where an interpolation routine is applied. Nowcasting maps are based on the SIRMUP (SIRM updated in real-time) concept, however, a different effective sunspot number (Reff) is estimated for each latitudinal zone, from which a synthetic Reff is calculated.

Early MAVEN Deep Dip campaign reveals thermosphere and ionosphere variability.

PubMed

Bougher, S; Jakosky, B; Halekas, J; Grebowsky, J; Luhmann, J; Mahaffy, P; Connerney, J; Eparvier, F; Ergun, R; Larson, D; McFadden, J; Mitchell, D; Schneider, N; Zurek, R; Mazelle, C; Andersson, L; Andrews, D; Baird, D; Baker, D N; Bell, J M; Benna, M; Brain, D; Chaffin, M; Chamberlin, P; Chaufray, J-Y; Clarke, J; Collinson, G; Combi, M; Crary, F; Cravens, T; Crismani, M; Curry, S; Curtis, D; Deighan, J; Delory, G; Dewey, R; DiBraccio, G; Dong, C; Dong, Y; Dunn, P; Elrod, M; England, S; Eriksson, A; Espley, J; Evans, S; Fang, X; Fillingim, M; Fortier, K; Fowler, C M; Fox, J; Gröller, H; Guzewich, S; Hara, T; Harada, Y; Holsclaw, G; Jain, S K; Jolitz, R; Leblanc, F; Lee, C O; Lee, Y; Lefevre, F; Lillis, R; Livi, R; Lo, D; Ma, Y; Mayyasi, M; McClintock, W; McEnulty, T; Modolo, R; Montmessin, F; Morooka, M; Nagy, A; Olsen, K; Peterson, W; Rahmati, A; Ruhunusiri, S; Russell, C T; Sakai, S; Sauvaud, J-A; Seki, K; Steckiewicz, M; Stevens, M; Stewart, A I F; Stiepen, A; Stone, S; Tenishev, V; Thiemann, E; Tolson, R; Toublanc, D; Vogt, M; Weber, T; Withers, P; Woods, T; Yelle, R

2015-11-06

The Mars Atmosphere and Volatile Evolution (MAVEN) mission, during the second of its Deep Dip campaigns, made comprehensive measurements of martian thermosphere and ionosphere composition, structure, and variability at altitudes down to ~130 kilometers in the subsolar region. This altitude range contains the diffusively separated upper atmosphere just above the well-mixed atmosphere, the layer of peak extreme ultraviolet heating and primary reservoir for atmospheric escape. In situ measurements of the upper atmosphere reveal previously unmeasured populations of neutral and charged particles, the homopause altitude at approximately 130 kilometers, and an unexpected level of variability both on an orbit-to-orbit basis and within individual orbits. These observations help constrain volatile escape processes controlled by thermosphere and ionosphere structure and variability. Copyright © 2015, American Association for the Advancement of Science.

Overview of the Upper Atmosphere Research Satellite: Observations from 1991 to 2002

NASA Technical Reports Server (NTRS)

Jackman, Charles H.; Douglass, Anne R.

2003-01-01

The Upper Atmosphere Research Satellite (UARS) was launched in September 1991 by the Space Shuttle Discovery and continues to make relevant atmospheric measurements (as of October 2002). This successful satellite has fostered a better understanding of the middle atmospheric processes, especially those important in the control of ozone. Seven of the original ten instruments aboard the UARS are still functional and six instruments regularly make measurements. The UARS is in a stable observing configuration, in spite of experiencing several anomalies over its lifetime. It is expected that the UARS will overlap the Earth Observing System (EOS) Aura satellite (scheduled launch in January 2004) for several months before the end of the UARS mission.

Model of the vertical structure of the optical parameters of the Neptune atmosphere.

NASA Astrophysics Data System (ADS)

Morozhenko, A. V.

Analyzes the wavelength dependence of the geometric albedo of Neptune's disk and estimates some parameters of the planet's atmosphere by the method based on the determination of deviations of the vertical structure of the cloud layer from the homogeneity condition. The ratio between the methane and gas scale heights is found to be about 0.4. For the upper atmosphere, components of methane, aerosol, the mean geometric radius of particles, the turbulent mixing coefficient are determined. Two solutions were found for deeper atmospheric layers. The first one suggests a rather dense cloud; in the second solution the lower cloud layer is an extension of the upper aerosol layer.

Improved Mars Upper Atmosphere Climatology

NASA Technical Reports Server (NTRS)

Bougher, S. W.

2004-01-01

The detailed characterization of the Mars upper atmosphere is important for future Mars aerobraking activities. Solar cycle, seasonal, and dust trends (climate) as well as planetary wave activity (weather) are crucial to quantify in order to improve our ability to reasonably depict the state of the Mars upper atmosphere over time. To date, our best information is found in the Mars Global Surveyor (MGS) Accelerometer (ACC) database collected during Phase 1 (Ls = 184 - 300; F10.7 = 70 - 90) and Phase 2 (Ls = 30 - 90; F10.7 = 90 - 150) of aerobraking. This database (100 - 170 km) consists of thermospheric densities, temperatures, and scale heights, providing our best constraints for exercising the coupled Mars General Circulation Model (MGCM) and the Mars Thermospheric General Circulation Model (MTGCM). The Planetary Data System (PDS) contains level 0 and 2 MGS Accelerometer data, corresponding to atmospheric densities along the orbit track. Level 3 products (densities, temperatures, and scale heights at constant altitudes) are also available in the PDS. These datasets provide the primary model constraints for the new MGCM-MTGCM simulations summarized in this report. Our strategy for improving the characterization of the Mars upper atmospheres using these models has been three-fold : (a) to conduct data-model comparisons using the latest MGS data covering limited climatic and weather conditions at Mars, (b) to upgrade the 15-micron cooling and near-IR heating rates in the MGCM and MTGCM codes for ad- dressing climatic variations (solar cycle and seasonal) important in linking the lower and upper atmospheres (including migrating tides), and (c) to exercise the detailed coupled MGCM and MTGCM codes to capture and diagnose the planetary wave (migrating plus non-migrating tidal) features throughout the Mars year. Products from this new suite of MGCM-MTGCM coupled simulations are being used to improve our predictions of the structure of the Mars upper atmosphere for the upcoming MRO aerobraking exercises in 2006. A Michigan website, containing MTGCM output fields from previous climate simulations, is being expanded to include new MGCM-MTGCM simulations addressing planetary wave influences upon thermospheric aerobraking fields (densities and temperatures). In addition, similar MTGCM output fields have been supplied to the MSFC MARSGRAM - 200X empirical model, which will be used in mission operations for conducting aerobraking maneuvers.

NIR-Driven Moist Upper Atmospheres of Synchronously Rotating Temperate Terrestrial Exoplanets

NASA Technical Reports Server (NTRS)

Fujii, Yuka; Del Genio, Anthony D.; Amundsen, David S.

2017-01-01

H2O is a key molecule in characterizing atmospheres of temperate terrestrial planets, and observations of transmission spectra are expected to play a primary role in detecting its signatures in the near future. The detectability of H2O absorption features in transmission spectra depends on the abundance of water vapor in the upper part of the atmosphere. We study the three-dimensional distribution of atmospheric H2O for synchronously rotating Earth-sized aquaplanets using the general circulation model (GCM) ROCKE-3D, and examine the effects of total incident flux and stellar spectral type. We observe a more gentle increase of the water vapor mixing ratio in response to increased incident flux than one-dimensional models suggest, in qualitative agreement with the climate-stabilizing effect of clouds around the substellar point previously observed in GCMs applied to synchronously rotating planets. However, the water vapor mixing ratio in the upper atmosphere starts to increase while the surface temperature is still moderate. This is explained by the circulation in the upper atmosphere being driven by the radiative heating due to absorption by water vapor and cloud particles, causing efficient vertical transport of water vapor. Consistently, the water vapor mixing ratio is found to be well-correlated with the near-infrared portion of the incident flux. We also simulate transmission spectra based on the GCM outputs, and show that for the more highly irradiated planets, the H2O signatures may be strengthened by a factor of a few, loosening the observational demands for a H2O detection.

Sensitivity of idealised baroclinic waves to mean atmospheric temperature and meridional temperature gradient changes

NASA Astrophysics Data System (ADS)

Rantanen, Mika; Räisänen, Jouni; Sinclair, Victoria A.; Järvinen, Heikki

2018-06-01

The sensitivity of idealised baroclinic waves to different atmospheric temperature changes is studied. The temperature changes are based on those which are expected to occur in the Northern Hemisphere with climate change: (1) uniform temperature increase, (2) decrease of the lower level meridional temperature gradient, and (3) increase of the upper level temperature gradient. Three sets of experiments are performed, first without atmospheric moisture, thus seeking to identify the underlying adiabatic mechanisms which drive the response of extra-tropical storms to changes in the environmental temperature. Then, similar experiments are performed in a more realistic, moist environment, using fixed initial relative humidity distribution. Warming the atmosphere uniformly tends to decrease the kinetic energy of the cyclone, which is linked both to a weaker capability of the storm to exploit the available potential energy of the zonal mean flow, and less efficient production of eddy kinetic energy in the wave. Unsurprisingly, the decrease of the lower level temperature gradient weakens the resulting cyclone regardless of the presence of moisture. The increase of the temperature gradient in the upper troposphere has a more complicated influence on the storm dynamics: in the dry atmosphere the maximum eddy kinetic energy decreases, whereas in the moist case it increases. Our analysis suggests that the slightly unexpected decrease of eddy kinetic energy in the dry case with an increased upper tropospheric temperature gradient originates from the weakening of the meridional heat flux by the eddy. However, in the more realistic moist case, the diabatic heating enhances the interaction between upper- and low-level potential vorticity anomalies and hence helps the surface cyclone to exploit the increased upper level baroclinicity.

The Variability of Atmospheric Deuterium Brightness at Mars: Evidence for Seasonal Dependence

NASA Astrophysics Data System (ADS)

Mayyasi, Majd; Clarke, John; Bhattacharyya, Dolon; Deighan, Justin; Jain, Sonal; Chaffin, Michael; Thiemann, Edward; Schneider, Nick; Jakosky, Bruce

2017-10-01

The enhanced ratio of deuterium to hydrogen on Mars has been widely interpreted as indicating the loss of a large column of water into space, and the hydrogen content of the upper atmosphere is now known to be highly variable. The variation in the properties of both deuterium and hydrogen in the upper atmosphere of Mars is indicative of the dynamical processes that produce these species and propagate them to altitudes where they can escape the planet. Understanding the seasonal variability of D is key to understanding the variability of the escape rate of water from Mars. Data from a 15 month observing campaign, made by the Mars Atmosphere and Volatile Evolution Imaging Ultraviolet Spectrograph high-resolution echelle channel, are used to determine the brightness of deuterium as observed at the limb of Mars. The D emission is highly variable, with a peak in brightness just after southern summer solstice. The trends of D brightness are examined against extrinsic as well as intrinsic sources. It is found that the fluctuations in deuterium brightness in the upper atmosphere of Mars (up to 400 km), corrected for periodic solar variations, vary on timescales that are similar to those of water vapor fluctuations lower in the atmosphere (20-80 km). The observed variability in deuterium may be attributed to seasonal factors such as regional dust storm activity and subsequent circulation lower in the atmosphere.

Observations of seasonal variations in atmospheric greenhouse trapping and its enhancement at high sea surface temperature

NASA Technical Reports Server (NTRS)

Hallberg, Robert; Inamdar, Anand K.

1993-01-01

Greenhouse trapping is examined theoretically using a version of the radiative transfer equations that demonstrates how atmospheric greenhouse trapping can vary. Satellite observations of atmospheric greenhouse trapping are examined for four months representing the various seasons. The cause of the super greenhouse effect at the highest SSTs is examined, and four processes are found to contribute. The middle and upper troposphere must be particularly moist and the temperature lapse rate must be increasingly unstable over the warmest regions to explain the observed distribution of atmospheric greenhouse trapping. Since the highest SSTs are generally associated with deep convection, this suggests that deep convection acts to moisten the middle and upper troposphere in regions of the highest SSTs relative to other regions. The tropical atmospheric circulation acts to both increase the temperature lapse rate and greatly increase the atmospheric water vapor concentration with spatially increasing SST.

[The response of the upper respiratory tract to the impact of atmospheric pollution].

PubMed

Mukhamadiev, R A; Ismagilov, Sh M

2015-01-01

The present literature review characterizes the environmental conditions in the Russian Federation in general and the Republic of Tatarstan in particular with special reference to the influence of atmospheric pollution on the development and the clinical picture of the diseases of the respiratory organs including pathology of the upper respiratory tract in the populations of the industrial centres and other environmentally unfriendly areas. The views of the domestic and foreign authors concerning the role of the environmental factors in the clinical picture of the upper respiratory tract disorders are described in detail. The authors emphasize the necessity of the further investigationsinto this problem and the development of the methods for the prevention of diseases of the upper respiratory react.

Planet-B: A Japanese Mars aeronomy observer

NASA Technical Reports Server (NTRS)

Tsuruda, K.

1992-01-01

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

Refinement of myotome values in the upper limb: Evidence from brachial plexus injuries.

PubMed

Bell, S W; Brown, M J C; Hems, T J

2017-02-01

We reviewed patients with partial supraclavicular brachial plexus injuries in order to refine the myotome values of the upper limb. Forty-two patients with defined partial injuries to the supraclavicular brachial plexus were reviewed from a prospective database. The injuries patterns covered C5, C5-6, C5-7, C5-8, C7-T1 and C8-T1 roots. Upper plexus injuries were classified on the basis of surgical exploration and intraoperative stimulation and lower plexus injuries from MRI. Flexor Carpi Radialis (FCR) was paralyzed in C5-7 injuries, in addition to paralysis of deltoid, supraspinatus, infraspinatus and biceps, when compared to C5-6 injuries. Complete paralysis of Flexor Digitorum Profundus (FDP) and Flexor Digitorum Superficialis (FDS) to all digits was identified in C7-T1 injuries. In C5-8 injuries weakness was noted in FDP of ulnar digits and intrinsics innervated by the ulnar nerve, while in C8-T1 injuries paralysis was noted in the FDP to the radial digits. All patients with C8-T1 injuries had paralysis of FDS and the thenar muscles. In upper plexus injuries paralysis of FCR indicated involvement of C7 root in addition to C5 and C6 roots. The results provide new detail of innervation of muscles acting on the hand. Flexor muscles and intrinsic muscles of the thumb and radial fingers (median nerve) have an important contribution from T1, while for those acting on the ulnar digits (ulnar nerve) the main contribution is from C8 with some input from C7. T1 also gives consistent innervation to extensor pollicis longus. A revised myotome chart for the upper limb is proposed. Copyright © 2015 Royal College of Surgeons of Edinburgh (Scottish charity number SC005317) and Royal College of Surgeons in Ireland. Published by Elsevier Ltd. All rights reserved.

Effects of Subsonic Aircraft on Aerosols and Cloudiness in the Upper Troposphere and Lower Stratosphere

NASA Technical Reports Server (NTRS)

Detwiler, Andrew G.

1997-01-01

This work was accomplished primarily by Allison G. Wozniak, a graduate research assistant who has completed the Master of Science in Meteorology program at the South Dakota School of Mines and Technology. Ms. Wozniak was guided and assisted in her work by L. R. Johnson and the principal investigator. Invaluable guidance was supplied by Dr. James Holdeman, NASA Lewis, the manager of the Global Atmospheric Sampling Program (GASP). Dr. Gregory Nastrom, St. Cloud (Minnesota) State University, who has used the GASP data set to provide unique views of the distribution of ozone, clouds, and atmospheric waves and turbulence, in the upper troposphere/lower stratosphere region, was also extremely helpful. Finally, Dr. Terry Deshler, University of Wyoming, supplied observations from the university's upper atmospheric monitoring program for comparison to GASP data.

The upper atmosphere of Venus: A tentative explanation of its rotation

NASA Technical Reports Server (NTRS)

Boyer, C.

1986-01-01

The upper atmosphere of Venus seems to revolve every 4 days, while the planet rotates in 243 days. Mariner 10 UV data on the changing positions of dark spots in the upper Venusian clouds have supported estimations of speeds ranging from 120-240 m/s. High rates of acceleration and deceleration occur on the night side, the former between -110 to -90 deg and the latter continuing to -50 deg. Arch and Y formations have been seen repeatedly between -110 to -70 deg. The highest are seen at about -90 deg and the lowest at about -30 deg. The temperature of the cloud layer at 60 km altitude is about 20 C, the pressure is nearly one earth atmosphere, and complex molecules, including O, C, H, N and S and combinations of these are present in abundance.

The Solar-Terrestrial Environment

NASA Astrophysics Data System (ADS)

Hargreaves, John Keith

1995-05-01

The book begins with three introductory chapters that provide some basic physics and explain the principles of physical investigation. The principal material contained in the main part of the book covers the neutral and ionized upper atmosphere, the magnetosphere, and structures, dynamics, disturbances, and irregularities. The concluding chapter deals with technological applications. The account is introductory, at a level suitable for readers with a basic background in engineering or physics. The intent is to present basic concepts, and for that reason, the mathematical treatment is not complex. SI units are given throughout, with helpful notes on cgs units where these are likely to be encountered in the research literature. This book is suitable for advanced undergraduate and graduate students who are taking introductory courses on upper atmospheric, ionospheric, or magnetospheric physics. This is a successor to The Upper Atmosphere and Solar-Terrestrial Relations, published in 1979.

Energy loss of solar p modes due to the excitation of magnetic sausage tube waves: Importance of coupling the upper atmosphere

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gascoyne, A.; Jain, R.; Hindman, B. W., E-mail: a.d.gascoyne@sheffield.ac.uk, E-mail: r.jain@sheffield.ac.uk

2014-07-10

We consider damping and absorption of solar p modes due to their energy loss to magnetic tube waves that can freely carry energy out of the acoustic cavity. The coupling of p modes and sausage tube waves is studied in a model atmosphere composed of a polytropic interior above which lies an isothermal upper atmosphere. The sausage tube waves, excited by p modes, propagate along a magnetic fibril which is assumed to be a vertically aligned, stratified, thin magnetic flux tube. The deficit of p-mode energy is quantified through the damping rate, Γ, and absorption coefficient, α. The variation ofmore » Γ and α as a function of frequency and the tube's plasma properties is studied in detail. Previous similar studies have considered only a subphotospheric layer, modeled as a polytrope that has been truncated at the photosphere. Such studies have found that the resulting energy loss by the p modes is very sensitive to the upper boundary condition, which, due to the lack of an upper atmosphere, have been imposed in a somewhat ad hoc manner. The model presented here avoids such problems by using an isothermal layer to model the overlying atmosphere (chromosphere, and, consequently, allows us to analyze the propagation of p-mode-driven sausage waves above the photosphere. In this paper, we restrict our attention to frequencies below the acoustic cut off frequency. We demonstrate the importance of coupling all waves (acoustic, magnetic) in the subsurface solar atmosphere with the overlying atmosphere in order to accurately model the interaction of solar f and p modes with sausage tube waves. In calculating the absorption and damping of p modes, we find that for low frequencies, below ≈3.5 mHz, the isothermal atmosphere, for the two-region model, behaves like a stress-free boundary condition applied at the interface (z = –z{sub 0}).« less

Energy Loss of Solar p Modes due to the Excitation of Magnetic Sausage Tube Waves: Importance of Coupling the Upper Atmosphere

NASA Astrophysics Data System (ADS)

Gascoyne, A.; Jain, R.; Hindman, B. W.

2014-07-01

We consider damping and absorption of solar p modes due to their energy loss to magnetic tube waves that can freely carry energy out of the acoustic cavity. The coupling of p modes and sausage tube waves is studied in a model atmosphere composed of a polytropic interior above which lies an isothermal upper atmosphere. The sausage tube waves, excited by p modes, propagate along a magnetic fibril which is assumed to be a vertically aligned, stratified, thin magnetic flux tube. The deficit of p-mode energy is quantified through the damping rate, Γ, and absorption coefficient, α. The variation of Γ and α as a function of frequency and the tube's plasma properties is studied in detail. Previous similar studies have considered only a subphotospheric layer, modeled as a polytrope that has been truncated at the photosphere. Such studies have found that the resulting energy loss by the p modes is very sensitive to the upper boundary condition, which, due to the lack of an upper atmosphere, have been imposed in a somewhat ad hoc manner. The model presented here avoids such problems by using an isothermal layer to model the overlying atmosphere (chromosphere, and, consequently, allows us to analyze the propagation of p-mode-driven sausage waves above the photosphere. In this paper, we restrict our attention to frequencies below the acoustic cut off frequency. We demonstrate the importance of coupling all waves (acoustic, magnetic) in the subsurface solar atmosphere with the overlying atmosphere in order to accurately model the interaction of solar f and p modes with sausage tube waves. In calculating the absorption and damping of p modes, we find that for low frequencies, below ≈3.5 mHz, the isothermal atmosphere, for the two-region model, behaves like a stress-free boundary condition applied at the interface (z = -z 0).

Royal London space analysis: plaster versus digital model assessment.

PubMed

Grewal, Balpreet; Lee, Robert T; Zou, Lifong; Johal, Ama

2017-06-01

With the advent of digital study models, the importance of being able to evaluate space requirements becomes valuable to treatment planning and the justification for any required extraction pattern. This study was undertaken to compare the validity and reliability of the Royal London space analysis (RLSA) undertaken on plaster as compared with digital models. A pilot study (n = 5) was undertaken on plaster and digital models to evaluate the feasibility of digital space planning. This also helped to determine the sample size calculation and as a result, 30 sets of study models with specified inclusion criteria were selected. All five components of the RLSA, namely: crowding; depth of occlusal curve; arch expansion/contraction; incisor antero-posterior advancement and inclination (assessed from the pre-treatment lateral cephalogram) were accounted for in relation to both model types. The plaster models served as the gold standard. Intra-operator measurement error (reliability) was evaluated along with a direct comparison of the measured digital values (validity) with the plaster models. The measurement error or coefficient of repeatability was comparable for plaster and digital space analyses and ranged from 0.66 to 0.95mm. No difference was found between the space analysis performed in either the upper or lower dental arch. Hence, the null hypothesis was accepted. The digital model measurements were consistently larger, albeit by a relatively small amount, than the plaster models (0.35mm upper arch and 0.32mm lower arch). No difference was detected in the RLSA when performed using either plaster or digital models. Thus, digital space analysis provides a valid and reproducible alternative method in the new era of digital records. © The Author 2016. Published by Oxford University Press on behalf of the European Orthodontic Society. All rights reserved. For permissions, please email: journals.permissions@oup.com

Preliminary survey of propulsion using chemical energy stored in the upper atmosphere

NASA Technical Reports Server (NTRS)

Baldwin, Lionel V; Blackshear, Perry L

1958-01-01

Ram-jet cycles that use the chemical energy of dissociated oxygen for propulsion in the ionosphere are presented. After a review of the properties and compositions of the upper atmosphere, the external drag, recombination kinetics, and aerodynamic-heating problems of an orbiting ram jet are analyzed. The study indicates that the recombination ram jet might be useful for sustaining a satellite at an altitude of about 60 miles. Atmospheric composition and recombination-rate coefficients were too uncertain for more definite conclusions. The ram jet is a marginal device even in the optimistic view.

Near-Inertial and Thermal Upper Ocean Response to Atmospheric Forcing in the North Atlantic Ocean

DTIC Science & Technology

2010-06-01

meridional transport of heat (Hoskins and Valdes, 1990). Formation of North Atlantic Subtropical Mode Water is thought to take place during the...North Atlantic Ocean MIT/WHOI Joint Program in Oceanography/ Applied Ocean Science and Engineering Massachusetts Institute of Technology Woods Hole...Oceanographic Institution MITIWHOI 2010-16 Near-inertial and Thermal Upper Ocean Response to Atmospheric Forcing in the North Atlantic Ocean by

Vertically Propagating Waves in the Upper Atmosphere of Saturn From Cassini Radio Occultations

NASA Astrophysics Data System (ADS)

Schinder, P. J.; Flasar, F. M.; Kliore, A. J.; French, R. G.; Marouf, E. A.; Nagy, A.; Rappaport, N.; Anabtawi, A.; Asmar, S.; Barbinis, E.; Fleischman, D. U.; Goltz, G. L.; Johnston, D. V.; Rochblatt, D.; McGhee, C. A.

2005-12-01

We present results from 12 ingress and egress soundings done within 10 degrees of Saturn's equator. Above the 100-mbar level, near the tropopause, the vertical profiles of temperature are marked by undulatory structure that may be associated with vertically propagating waves. We determine the properties and spectra of these waves, and speculate on their origins and their dynamical effects on the upper atmosphere.

Ground-based Observations for the Upper Atmosphere at King Sejong Station, Antarctica

NASA Astrophysics Data System (ADS)

Jee, Geonhwa; Kim, Jeong-Han; Lee, Changsup; Kim, Yong Ha

2014-06-01

Since the operation of the King Sejong Station (KSS) started in Antarctic Peninsula in 1989, there have been continuous efforts to perform the observation for the upper atmosphere. The observations during the initial period of the station include Fabry-Perot Interferometer (FPI) and Michelson Interferometer for the mesosphere and thermosphere, which are no longer in operation. In 2002, in collaboration with York University, Canada, the Spectral Airglow Temperature Imager (SATI) was installed to observe the temperature in the mesosphere and lower thermosphere (MLT) region and it has still been producing the mesopause temperature data until present. The observation was extended by installing the meteor radar in 2007 to observe the neutral winds and temperature in the MLT region during the day and night in collaboration with Chungnam National University. We also installed the all sky camera in 2008 to observe the wave structures in the MLT region. All these observations are utilized to study on the physical characteristics of the MLT region and also on the wave phenomena such as the tide and gravity wave in the upper atmosphere over KSS that is well known for the strong gravity wave activity. In this article, brief introductions for the currently operating instruments at KSS will be presented with their applications for the study of the upper atmosphere

Energy Dissipation in the Upper Atmospheres of TRAPPIST-1 Planets

NASA Astrophysics Data System (ADS)

Cohen, Ofer; Glocer, Alex; Garraffo, Cecilia; Drake, Jeremy J.; Bell, Jared M.

2018-03-01

We present a method to quantify the upper limit of the energy transmitted from the intense stellar wind to the upper atmospheres of three of the TRAPPIST-1 planets (e, f, and g). We use a formalism that treats the system as two electromagnetic regions, where the efficiency of the energy transmission between one region (the stellar wind at the planetary orbits) to the other (the planetary ionospheres) depends on the relation between the conductances and impedances of the two regions. Since the energy flux of the stellar wind is very high at these planetary orbits, we find that for the case of high transmission efficiency (when the conductances and impedances are close in magnitude), the energy dissipation in the upper planetary atmospheres is also very large. On average, the Ohmic energy can reach 0.5–1 W m‑2, about 1% of the stellar irradiance and 5–15 times the EUV irradiance. Here, using constant values for the ionospheric conductance, we demonstrate that the stellar wind energy could potentially drive large atmospheric heating in terrestrial planets, as well as in hot Jupiters. More detailed calculations are needed to assess the ionospheric conductance and to determine more accurately the amount of heating the stellar wind can drive in close-orbit planets.

Ionization Efficiency in the Dayside Martian Upper Atmosphere

NASA Astrophysics Data System (ADS)

Cui, J.; Wu, X.-S.; Xu, S.-S.; Wang, X.-D.; Wellbrock, A.; Nordheim, T. A.; Cao, Y.-T.; Wang, W.-R.; Sun, W.-Q.; Wu, S.-Q.; Wei, Y.

2018-04-01

Combining the Mars Atmosphere and Volatile Evolution measurements of neutral atmospheric density, solar EUV/X-ray flux, and differential photoelectron intensity made during 240 nominal orbits, we calculate the ionization efficiency, defined as the ratio of the secondary (photoelectron impact) ionization rate to the primary (photon impact) ionization rate, in the dayside Martian upper atmosphere under a range of solar illumination conditions. Both the CO2 and O ionization efficiencies tend to be constant from 160 km up to 250 km, with respective median values of 0.19 ± 0.03 and 0.27 ± 0.04. These values are useful for fast calculation of the ionization rate in the dayside Martian upper atmosphere, without the need to construct photoelectron transport models. No substantial diurnal and solar cycle variations can be identified, except for a marginal trend of reduced ionization efficiency approaching the terminator. These observations are favorably interpreted by a simple scenario with ionization efficiencies, as a first approximation, determined by a comparison between relevant cross sections. Our analysis further reveals a connection between regions with strong crustal magnetic fields and regions with high ionization efficiencies, which are likely indicative of more efficient vertical transport of photoelectrons near magnetic anomalies.

[Analysis on concentration variety characteristics of atmospheric ozone under the boundary layer in Beijing].

PubMed

Zong, Xue-Mei; Wang, Geng-Chen; Chen, Hong-Bin; Wang, Pu-Cai; Xuan, Yue-Jian

2007-11-01

Based on the atmospheric ozone sounding data, the average monthly and seasonal variety principles of atmospheric ozone concentration during six years are analyzed under the boundary layer in Beijing. The results show that the monthly variation of atmospheric ozone are obvious that the minimum values appear in January from less than 10 x 10(-9) on ground to less than 50 x 10(-9) on upper layer (2 km), but the maximum values appear in June from 85 x 10(-9) on ground to more than 90 x 10(-9) on upper layer. The seasonal variation is also clear that the least atmospheric ozone concentration is in winter and the most is in summer, but variety from ground to upper layer is largest in winter and least in summer. According to the type of outline, the outline of ozone concentration is composite of three types which are winter type, summer type and spring-autumn type. The monthly ozone concentration in different heights is quite different. After analyzing the relationship between ozone concentration and meteorological factors, such as temperature and humidity, we find ozone concentration on ground is linear with temperature and the correlation coefficient is more than 85 percent.

Thrombosis of digital arteries associated with tamoxifen use: case report.

PubMed

Hutchison, Richard L; Rayan, Ghazi M

2012-02-01

Arterial thrombosis in the upper extremity occurs often at the wrist. We report a unique case of thrombosis that involved multiple digital arteries, without radial or ulnar artery involvement, which developed only after using tamoxifen despite chronic occupational blunt percussive hand use. Revascularization was achieved after thrombectomy. Multiple digital arterial thromboses may complicate the use of tamoxifen. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Extratropical Influence of Upper Tropospheric Water Vapor on Greenhouse Warming

NASA Technical Reports Server (NTRS)

Hu, H.; Liu, W.

1998-01-01

The purpose of this paper is to re-examine the impact of upper tropospheric water vapor on greenhouse warming in midlatitudes by analyzing the recent observations of the upper tropospheric water vapor from the Microwave Limb Sounder (MLS) on the Upper Atmosphere Research Satellite (UARS), in conjuction with other space-based measurement and model simulation products.

Solar Magnetism eXplorer (Solme X)

NASA Technical Reports Server (NTRS)

Peter, Hardi; Abbo, L.; Andretta, V.; Auchere, F.; Bemporad, A.; Berrilli, F.; Bommier, V.; Cassini, R.; Curdt, W.; Davila, J.;

A Model of Titan-like Chemistry to Connect Experiments and Cassini Observations

NASA Astrophysics Data System (ADS)

Raymond, Alexander W.; Sciamma-O’Brien, Ella; Salama, Farid; Mazur, Eric

2018-02-01

A numerical model is presented for interpreting the chemical pathways that lead to the experimental mass spectra acquired in the Titan Haze Simulation (THS) laboratory experiments and for comparing the electron density and temperature of the THS plasma to observations made at Titan by the Cassini spacecraft. The THS plasma is a pulsed glow-discharge experiment designed to simulate the reaction of N2/CH4-dominated gas in Titan's upper atmosphere. The transient, one-dimensional model of THS chemistry tracks the evolution of more than 120 species in the direction of the plasma flow. As the minor species C2H2 and C2H4 are added to the N2/CH4-based mixture, the model correctly predicts the emergence of reaction products with up to five carbon atoms in relative abundances that agree well with measured mass spectra. Chemical growth in Titan's upper atmosphere transpires through ion–neutral and neutral–neutral chemistry, and the main reactions involving a series of known atmospheric species are retrieved from the calculation. The model indicates that the electron density and chemistry are steady during more than 99% of the 300 μs long discharge pulse. The model also suggests that the THS ionization fraction and electron temperature are comparable to those measured in Titan's upper atmosphere. These findings reaffirm that the THS plasma is a controlled analog environment for studying the first and intermediate steps of chemistry in Titan's upper atmosphere.

Modeling the Atmospheric Phase Effects of a Digital Antenna Array Communications System

NASA Technical Reports Server (NTRS)

Tkacenko, A.

2006-01-01

In an antenna array system such as that used in the Deep Space Network (DSN) for satellite communication, it is often necessary to account for the effects due to the atmosphere. Typically, the atmosphere induces amplitude and phase fluctuations on the transmitted downlink signal that invalidate the assumed stationarity of the signal model. The degree to which these perturbations affect the stationarity of the model depends both on parameters of the atmosphere, including wind speed and turbulence strength, and on parameters of the communication system, such as the sampling rate used. In this article, we focus on modeling the atmospheric phase fluctuations in a digital antenna array communications system. Based on a continuous-time statistical model for the atmospheric phase effects, we show how to obtain a related discrete-time model based on sampling the continuous-time process. The effects of the nonstationarity of the resulting signal model are investigated using the sample matrix inversion (SMI) algorithm for minimum mean-squared error (MMSE) equalization of the received signal

A NEAR-INFRARED SPECTROSCOPIC SURVEY OF COOL WHITE DWARFS IN THE SLOAN DIGITAL SKY SURVEY

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kilic, Mukremin; Kowalski, Piotr M.; Von Hippel, Ted

2009-07-15

We present near-infrared photometric observations of 15 and spectroscopic observations of 38 cool white dwarfs (WDs). This is the largest near-infrared spectroscopic survey of cool WDs to date. Combining the Sloan Digital Sky Survey photometry and our near-infrared data, we perform a detailed model atmosphere analysis. The spectral energy distributions of our objects are explained fairly well by model atmospheres with temperatures ranging from 6300 K down to 4200 K. Two WDs show significant absorption in the infrared, and are best explained with mixed H/He atmosphere models. Based on the up-to-date model atmosphere calculations by Kowalski and Saumon, we findmore » that the majority of the stars in our sample have hydrogen-rich atmospheres. We do not find any pure helium atmosphere WDs below 5000 K, and we find a trend of increasing hydrogen to helium ratio with decreasing temperature. These findings present an important challenge to understanding the spectral evolution of WDs.« less

On the chemistry of Jupiter's upper atmosphere

USGS Publications Warehouse

Saslaw, W.C.; Wildey, R.L.

1967-01-01

We conduct a first investigation into the ion-molecule chemistry of the upper Jovian atmosphere. Experimental results show that intense ultraviolet radiation reacts with the constituents of the Jovian atmosphere to produce C2H4, C2H6, C3H8, and higher polymers. The general procedure for calculating both equilibrium and nonequilibrium abundances of these products is formulated and applied to the case of the surface passage of a satellite shadow. A specific example is made of ethylene, for which an analytical approximation gives 1010 molecules in an atmospheric column of 1 cm2 cross section after a very rapid rise to equilibrium. Such a concentration of ethylene does not substantially affect the infrared radiation in the shadow. ?? 1967.

A Shuttle Upper Atmosphere Mass Spectrometer /SUMS/ experiment

NASA Technical Reports Server (NTRS)

Blanchard, R. C.; Duckett, R. J.; Hinson, E. W.

1982-01-01

A magnetic mass spectrometer is currently being adapted to the Space Shuttle Orbiter to provide repeated high altitude atmosphere data to support in situ rarefied flow aerodynamics research, i.e., in the high velocity, low density flight regime. The experiment, called Shuttle Upper Atmosphere Mass Spectrometer (SUMS), is the first attempt to design mass spectrometer equipment for flight vehicle aerodynamic data extraction. The SUMS experiment will provide total freestream atmospheric quantitites, principally total mass density, above altitudes at which conventional pressure measurements are valid. Experiment concepts, the expected flight profile, tradeoffs in the design of the total system and flight data reduction plans are discussed. Development plans are based upon a SUMS first flight after the Orbiter initial development flights.

How Many Convective Zones Are There in the Atmosphere of Venus?

NASA Astrophysics Data System (ADS)

Moroz, V. I.; Rodin, A. V.

2002-11-01

The qualitative characteristics of the vertical structure of the atmospheres of Venus and the Earth essentially differ. For instance, there are at least two, instead of one, zones with normal (thermal) convection on Venus. The first one is near the surface (a boundary layer); the second is at the altitudes of the lower part of the main cloud layer between 49 and 55 km. Contrary to the hypotheses proposed by Izakov (2001, 2002), the upper convective zone prevents energy transfer from the upper clouds to the subcloud atmosphere by ``anomalous turbulent heat conductivity.'' It is possible, however, that the anomalous turbulent heat conductivity takes part in the redistribution of the heat fluxes within the lower (subcloud) atmosphere.

Developing the Vision: Preparing Teachers to Deliver a Digital World-Class Education System

ERIC Educational Resources Information Center

Lane, Jenny M.

2012-01-01

In 2008 Australians were promised a "Digital Education Revolution" by the government to dramatically change classroom education and build a "world-class education system". Eight billion dollars have been spent providing computer equipment for upper secondary classrooms, yet there is little evidence that a revolution has…

NIR-driven Moist Upper Atmospheres of Synchronously Rotating Temperate Terrestrial Exoplanets

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fujii, Yuka; Del Genio, Anthony D.; Amundsen, David S.

H{sub 2}O is a key molecule in characterizing atmospheres of temperate terrestrial planets, and observations of transmission spectra are expected to play a primary role in detecting its signatures in the near future. The detectability of H{sub 2}O absorption features in transmission spectra depends on the abundance of water vapor in the upper part of the atmosphere. We study the three-dimensional distribution of atmospheric H{sub 2}O for synchronously rotating Earth-sized aquaplanets using the general circulation model (GCM) ROCKE-3D, and examine the effects of total incident flux and stellar spectral type. We observe a more gentle increase of the water vapormore » mixing ratio in response to increased incident flux than one-dimensional models suggest, in qualitative agreement with the climate-stabilizing effect of clouds around the substellar point previously observed in GCMs applied to synchronously rotating planets. However, the water vapor mixing ratio in the upper atmosphere starts to increase while the surface temperature is still moderate. This is explained by the circulation in the upper atmosphere being driven by the radiative heating due to absorption by water vapor and cloud particles, causing efficient vertical transport of water vapor. Consistently, the water vapor mixing ratio is found to be well-correlated with the near-infrared portion of the incident flux. We also simulate transmission spectra based on the GCM outputs, and show that for the more highly irradiated planets, the H{sub 2}O signatures may be strengthened by a factor of a few, loosening the observational demands for a H{sub 2}O detection.« less

Database for the geologic map of Upper Geyser Basin, Yellowstone National Park, Wyoming

USGS Publications Warehouse

Abendini, Atosa A.; Robinson, Joel E.; Muffler, L. J. Patrick; White, D. E.; Beeson, Melvin H.; Truesdell, A. H.

2015-01-01

This dataset contains contacts, geologic units, and map boundaries from Miscellaneous Investigations Series Map I-1371, "The Geologic map of upper Geyser Basin, Yellowstone, National Park, Wyoming". This dataset was constructed to produce a digital geologic map as a basis for ongoing studies of hydrothermal processes.

46 CFR 154.1345 - Gas detection.

Code of Federal Regulations, 2013 CFR

2013-10-01

... detector; (iii) If the vessel carries cargo that is heavier than the atmosphere of the space, each tube's... atmosphere of the space, each tube's open end in the upper part of the space; (v) If the vessel carries cargo that is heavier than the atmosphere of the space and another cargo that is lighter than the atmosphere...

46 CFR 154.1345 - Gas detection.

Code of Federal Regulations, 2012 CFR

2012-10-01

... detector; (iii) If the vessel carries cargo that is heavier than the atmosphere of the space, each tube's... atmosphere of the space, each tube's open end in the upper part of the space; (v) If the vessel carries cargo that is heavier than the atmosphere of the space and another cargo that is lighter than the atmosphere...

46 CFR 154.1345 - Gas detection.

Code of Federal Regulations, 2014 CFR

2014-10-01

... detector; (iii) If the vessel carries cargo that is heavier than the atmosphere of the space, each tube's... atmosphere of the space, each tube's open end in the upper part of the space; (v) If the vessel carries cargo that is heavier than the atmosphere of the space and another cargo that is lighter than the atmosphere...

Natural variability of tropical upper stratospheric ozone inferred from the Atmosphere Explorer backscatter ultraviolet experiment

NASA Technical Reports Server (NTRS)

Frederick, J. E.; Abrams, R. B.; Dasgupta, R.; Guenther, B.

1981-01-01

Analysis of backscattered ultraviolet radiances observed at tropical latitudes by the Atmosphere Explorer-E satellite reveals both annual and semiannual cycles in upper stratospheric ozone. The annual variation dominates the signal at wavelengths which sense ozone primarily above 45 km while below this, to the lowest altitude sensed, 35 km, the semiannual component has comparable amplitude. Comparison of radiance measurements taken with the same instrument at solar minimum during 1976 and solar maximum in 1979 show no significant differences. This suggests that variations in upper stratospheric ozone over the solar cycle are small, although the data presently available do not allow a definite conclusion.

Overview on recent upper atmosphere atomic oxygen measurements

NASA Astrophysics Data System (ADS)

Zhu, Yajun; Kaufmann, Martin; Chen, Qiuyu; Martin, Riese

2017-04-01

In recent years, new global datasets of atomic oxygen in the upper mesosphere and lower thermosphere have been presented. They are based on airglow measurements from low earth satellites. Surprisingly, the atomic oxygen abundance differs by 30-50% for similar atmospheric conditions. This paper gives an overview on the various atomic oxygen datasets available so far and presents most recent results obtained from measurements on Envisat. Differences between the datasets are discussed.

An implementation plan for priorities in solar-system space physics

NASA Technical Reports Server (NTRS)

Krimigis, Stamatios M.; Athay, R. Grant; Baker, Daniel; Fisk, Lennard A.; Fredricks, Robert W.; Harvey, John W.; Jokipii, Jack R.; Kivelson, Margaret; Mendillo, Michael; Nagy, Andrew F.

1985-01-01

The scientific objectives and implementation plans and priorities of the Space Science Board in areas of solar physics, heliospheric physics, magnetospheric physics, upper atmosphere physics, solar-terrestrial coupling, and comparative planetary studies are discussed and recommended programs are summarized. Accomplishments of Skylab, Solar Maximum Mission, Nimbus-7, and 11 other programs are highlighted. Detailed mission plans in areas of solar and heliospheric physics, plasma physics, and upper atmospheric physics are also described.

Upper Atmosphere Heating From Ocean-Generated Acoustic Wave Energy

DOE PAGES

Bowman, D. C.; Lees, J. M.

2018-04-27

We present that colliding sea surface waves generate the ocean microbarom, an acoustic signal that may transmit significant energy to the upper atmosphere. Previous estimates of acoustic energy flux from the ocean microbarom and mountain-wind interactions are on the order of 0.01 to 1 mW/m 2, heating the thermosphere by tens of Kelvins per day. We captured upgoing ocean microbarom waves with a balloon-borne infrasound microphone; the maximum acoustic energy flux was approximately 0.05 mW/m 2. This is about half the average value reported in previous ground-based microbarom observations spanning 8 years. The acoustic flux from the microbarom episode describedmore » here may have heated the thermosphere by several Kelvins per day while the source persisted. Lastly, we suggest that ocean wave models could be used to parameterize acoustically generated heating of the upper atmosphere based on sea state.« less

THE VARIABILITY OF HCN IN TITAN’S UPPER ATMOSPHERE AS IMPLIED BY THE CASSINI ION-NEUTRAL MASS SPECTROMETER MEASUREMENTS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cui, J.; Cao, Y.-T.; Lavvas, P. P.

2016-07-20

HCN is an important constituent in Titan’s upper atmosphere, serving as the main coolant in the local energy budget. In this study, we derive the HCN abundance at the altitude range of 960–1400 km, combining the Ion-Neutral Mass Spectrometer data acquired during a large number of Cassini flybys with Titan. Typically, the HCN abundance declines modestly with increasing altitude and flattens to a near constant level above 1200 km. The data reveal a tendency for dayside depletion of HCN, which is clearly visible below 1000 km but weakens with increasing altitude. Despite the absence of convincing anti-correlation between HCN volumemore » mixing ratio and neutral temperature, we argue that the variability in HCN abundance makes an important contribution to the large temperature variability observed in Titan’s upper atmosphere.« less

Upper Atmosphere Heating From Ocean-Generated Acoustic Wave Energy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bowman, D. C.; Lees, J. M.

We present that colliding sea surface waves generate the ocean microbarom, an acoustic signal that may transmit significant energy to the upper atmosphere. Previous estimates of acoustic energy flux from the ocean microbarom and mountain-wind interactions are on the order of 0.01 to 1 mW/m 2, heating the thermosphere by tens of Kelvins per day. We captured upgoing ocean microbarom waves with a balloon-borne infrasound microphone; the maximum acoustic energy flux was approximately 0.05 mW/m 2. This is about half the average value reported in previous ground-based microbarom observations spanning 8 years. The acoustic flux from the microbarom episode describedmore » here may have heated the thermosphere by several Kelvins per day while the source persisted. Lastly, we suggest that ocean wave models could be used to parameterize acoustically generated heating of the upper atmosphere based on sea state.« less

Monitoring Saturn's Upper Atmosphere Density Variations Using Helium 584 Airglow

NASA Astrophysics Data System (ADS)

Parkinson, Chris

2017-10-01

The study of He 584 Å brightnesses is interesting as the EUV (Extreme UltraViolet) planetary airglow have the potential to yield useful information about mixing and other important parameters in its thermosphere. Resonance scattering of sunlight by He atoms is the principal source of the planetary emission of He 585 Å. The principal parameter involved in determining the He 584 Å albedo are the He volume mixing ratio, f_He, well below the homopause. Our main science objective is to estimate the helium mixing ratio in the lower atmosphere. Specifically, He emissions come from above the homopause where optical depth trau=1 in H2 and therefore the interpretation depends mainly on two parameters: He mixing ratio of the lower atmosphere and K_z. The occultations of Koskinen et al (2015) give K_z with an accuracy that has never been possible before and the combination of occultations and airglow therefore provide estimates of the mixing ratio in the lower atmosphere. We make these estimates at several locations that can be reasonably studied with both occultations and airglow and then average the results. Our results lead to a greatly improved estimate of the mixing ratio of He in the upper atmosphere and below. The second objective is to constrain the dynamics in the atmosphere by using the estimate of the He mixing ratio from the main objective. Once we have an estimate of the He mixing ratio in the lower atmosphere that agrees with both occultations and airglow, helium becomes an effective tracer species as any variations in the Cassini UVIS helium data are direct indicator of changes in K_z i.e., dynamics. Our third objective is to connect this work to our Cassini UVIS data He 584 Å airglow analyses as they both cover the time span of the observations and allow us to monitor changes in the airglow observations that may correlate with changes in the state of the atmosphere as revealed by the occultations Saturn's upper thermosphere. This work helps to determine the mixing ratio of He and constrain dynamics in the upper atmosphere, both of which are high level science objectives of the Cassini mission.

Preliminary Results on Mars and the Siding Spring Meteor Shower from MAVEN’s Imaging UV Spectrograph

NASA Astrophysics Data System (ADS)

Deighan, Justin; Schneider, Nicholas

2015-04-01

The MAVEN mission to Mars is designed to study the upper atmosphere and its response to external drivers, searching for clues to the cause of long-term atmospheric loss. MAVEN carries the Imaging UV Spectrograph (IUVS) for remote sensing studies of the atmosphere through vertical scans from the limb through the corona, UV imaging of the planet and stellar occultations. Each observational mode has successfully observed the spectral features and spatial distributions as intended, confirming and expanding our understanding of the Mars upper atmosphere as observed by the Mariner spacecraft and Mars Express. Furthermore, IUVS witnessed the aftermath of an intense meteor shower on Mars caused by Comet Siding Spring. For a period of many hours, the planet’s UV spectrum was dominated by emission from ionized magnesium deposited by meteor ablation in the upper atmosphere. Initial results from the originally-planned Mars observations include:• Significant persistent structures in the thermospheric day glow emissions, dependent primarily on solar zenith angle, along with significant variability on daily timescales• Nitric oxide nightglow and low-level auroral emissions of substantially greater nightside extent than previously seen• The first vertical profiles of the D/H ratio in the atmosphere and their evolution with Mars season• The most complete maps and vertical profiles of H, C and O in the Mars corona• The first global snapshot of the middle atmosphere obtained by a day-long stellar occultation campaignOther results from the missions’s preliminary phases will be included.

Present State of Knowledge of the Upper Atmosphere 1996: An Assessment Report to Congress and the Environmental Protection Agency

NASA Technical Reports Server (NTRS)

Kurylo, M. J.; Kaye, J. A.; Decola, P. L.; Friedl, R. R.; Peterson, D. B.

1997-01-01

This document is issued in response to the Clean Air Act Amendment of 1990, Public Law 101-549, which mandates that the National Aeronautics and Space Administration (NASA) and other key agencies submit triennial report to congress and the Environmental Protection Agency. NASA is charged with the responsibility to report on the state of our knowledge of the Earth's upper atmosphere, particularly the Stratosphere. Part 1 of this report summarizes the objectives, status, and accomplishments of the research tasks supported under NASA's Upper Atmosphere Research Program and Atmospheric Chemistry Modeling and Analysis Program for the period of 1994-1996. Part 2 (this document) presents summaries of several scientific assessments, reviews, and summaries. These include the executive summaries of two scientific assessments: (Section B) 'Scientific Assessment of Ozone Depletion: 1994'; (Section C) 'l995 Scientific Assessment of the Atmospheric Effects of Stratospheric Aircraft); end of mission/series statements for three stratospherically-focused measurement campaigns: (Section D) 'ATLAS End-of-Series Statement'; (Section E) 'ASHOE/MAESA End-of-Mission Statement'; (Section F) 'TOTE/VOTE End-of-Mission Statement'; a summary of NASA's latest biennial review of fundamental photochemical processes important to atmospheric chemistry 'Chemical Kinetics and Photochemical Data for Use in Stratospheric Modeling'; and (Section H) the section 'Atmospheric Ozone Research" from the Mission to Planet Earth Science Research Plan, which describes NASA's current and future research activities related to both tropospheric and stratospheric chemistry.

Active Upper-atmosphere Chemistry and Dynamics from Polar Circulation Reversal on Titan

NASA Technical Reports Server (NTRS)

Teanby, Nicholas A.; Irwin, Patrick Gerard Joseph; Nixon, Conor A.; DeKok, Remco; Vinatier, Sandrine; Coustenis, Athena; Sefton-Nash, Elliot; Calcutt, Simon B.; Flasar, Michael F.

2012-01-01

Saturn's moon Titan has a nitrogen atmosphere comparable to Earth's, with a surface pressure of 1.4 bar. Numerical models reproduce the tropospheric conditions very well but have trouble explaining the observed middle-atmosphere temperatures, composition and winds. The top of the middle-atmosphere circulation has been thought to lie at an altitude of 450 to 500 kilometres, where there is a layer of haze that appears to be separated from the main haze deck. This 'detached' haze was previously explained as being due to the colocation of peak haze production and the limit of dynamical transport by the circulation's upper branch. Herewe report a build-up of trace gases over the south pole approximately two years after observing the 2009 post-equinox circulation reversal, from which we conclude that middle-atmosphere circulation must extend to an altitude of at least 600 kilometres. The primary drivers of this circulation are summer-hemisphere heating of haze by absorption of solar radiation and winter-hemisphere cooling due to infrared emission by haze and trace gases; our results therefore imply that these effects are important well into the thermosphere (altitudes higher than 500 kilometres). This requires both active upper-atmosphere chemistry, consistent with the detection of high-complexity molecules and ions at altitudes greater than 950 kilometres, and an alternative explanation for the detached haze, such as a transition in haze particle growth from monomers to fractal structures.

LVGEMS Time-of-Flight Mass Spectrometry on Satellites

NASA Technical Reports Server (NTRS)

Herrero, Federico

2013-01-01

NASA fs investigations of the upper atmosphere and ionosphere require measurements of composition of the neutral air and ions. NASA is able to undertake these observations, but the instruments currently in use have their limitations. NASA has extended the scope of its research in the atmosphere and now requires more measurements covering more of the atmosphere. Out of this need, NASA developed multipoint measurements using miniaturized satellites, also called nanosatellites (e.g., CubeSats), that require a new generation of spectrometers that can fit into a 4 4 in. (.10 10 cm) cross-section in the upgraded satellites. Overall, the new mass spectrometer required for the new depth of atmospheric research must fulfill a new level of low-voltage/low-power requirements, smaller size, and less risk of magnetic contamination. The Low-Voltage Gated Electrostatic Mass Spectrometer (LVGEMS) was developed to fulfill these requirements. The LVGEMS offers a new spectrometer that eliminates magnetic field issues associated with magnetic sector mass spectrometers, reduces power, and is about 1/10 the size of previous instruments. LVGEMS employs the time of flight (TOF) technique in the GEMS mass spectrometer previously developed. However, like any TOF mass spectrometer, GEMS requires a rectangular waveform of large voltage amplitude, exceeding 100 V -- that means that the voltage applied to one of the GEMS electrodes has to change from 0 to 100 V in a time of only a few nanoseconds. Such electronic speed requires more power than can be provided in a CubeSat. In the LVGEMS, the amplitude of the rectangular waveform is reduced to about 1 V, compatible with digital electronics supplies and requiring little power.

Measurement of solar extinction in tower plants with digital cameras

NASA Astrophysics Data System (ADS)

Ballestrín, J.; Monterreal, R.; Carra, M. E.; Fernandez-Reche, J.; Barbero, J.; Marzo, A.

2016-05-01

Atmospheric extinction of solar radiation between the heliostat field and the receiver is accepted as a non-negligible source of energy loss in the increasingly large central receiver plants. However, the reality is that there is currently no reliable measurement method for this quantity and at present these plants are designed, built and operated without knowing this local parameter. Nowadays digital cameras are used in many scientific applications for their ability to convert available light into digital images. Its broad spectral range, high resolution and high signal to noise ratio, make them an interesting device in solar technology. In this work a method for atmospheric extinction measurement based on digital images is presented. The possibility of defining a measurement setup in circumstances similar to those of a tower plant increases the credibility of the method. This procedure is currently being implemented at Plataforma Solar de Almería.

The satellite power system - Assessment of the environmental impact on middle atmosphere composition and on climate

NASA Technical Reports Server (NTRS)

Whitten, R. C.; Borucki, W. J.; Park, C.; Pfister, L.; Woodward, H. T.; Turco, R. P.; Capone, L. A.; Riegel, C. A.; Kropp, T.

1982-01-01

Numerical models were developed to calculate the total deposition of watervapor, hydrogen, CO2, CO, SO2, and NO in the middle atmosphere from operation of heavy lift launch vehicles (HLLV) used to build a satellite solar power system (SPS). The effects of the contaminants were examined for their effects on the upper atmosphere. One- and two-dimensional models were formulated for the photochemistry of the upper atmosphere and for rocket plumes and reentry. An SPS scenario of 400 launches per year for 10 yr was considered. The build-up of the contaminants in the atmosphere was projected to have no significant effects, even at the launch latitude. Neither would there by any dangerous ozone depletion. It was found that H, OH, and HO2 species would double in the thermosphere. No measurable changes in climate were foreseen.

Digital atmospheres: affective practices of care in Elefriends.

PubMed

Tucker, Ian M; Goodings, Lewis

2017-05-01

This article develops the concept of digital atmosphere to analyse the affective power of social media to shape practices of care and support for people living with mental distress. Using contemporary accounts of affective atmospheres, the article focuses on feelings of distress, support and care that unfold through digital atmospheres. The power of social media intersects with people's support and care-seeking practices in multiple ways and not in a straightforward model of 'accessing or providing support'. Indeed, we find that the caring relations developed through social media often need to be cared for themselves. The article draws on online and interview data from a larger project investigating how practices of care and support are (re)configured in the mental health-related social media site Elefriends. Users have to negotiate the disruption of moving support online, as well as the possibility of becoming subject to a fragility in care, in which caring for oneself becomes bound up in the ambiguities of caring for others. We argue that understanding how experiences of distress are shaped by social media is essential for understanding the implications of the increased digitisation of mental healthcare. © 2017 Foundation for the Sociology of Health & Illness.

International cooperation between Japanese IUGONET and EU ESPAS projects on development of the metadata database for upper atmospheric study

NASA Astrophysics Data System (ADS)

Yatagai, Akiyo; Ritschel, Bernd; Iyemori, Tomohiko; Koyama, Yukinobu; Hori, Tomoaki; Abe, Shuji; Tanaka, Yoshimasa; Shinbori, Atsuki; UeNo, Satoru; Sato, Yuka; Yagi, Manabu

2013-04-01

The upper atmospheric observational study is the area which an international collaboration is crucially important. The Japanese Inter-university Upper atmosphere Global Observation NETwork project (2009-2014), IUGONET, is an inter-university program by the National Institute of Polar Research (NIPR), Tohoku University, Nagoya University, Kyoto University, and Kyushu University to build a database of metadata for ground-based observations of the upper atmosphere. In order to investigate the mechanism of long-term variations in the upper atmosphere, we need to combine various types of in-situ observations and to accelerate data exchange. The IUGONET institutions have been archiving observed data by radars, magnetometers, photometers, radio telescopes, helioscopes, etc. in various altitude layers from the Earth's surface to the Sun. The IUGONET has been developing systems for searching metadata of these observational data, and the metadata database (MDB) has already been operating since 2011. It adopts DSPACE system for registering metadata, and it uses an extension of the SPASE data model of describing metadata, which is widely used format in the upper atmospheric society including that in USA. The European Union project ESPAS (2011-2015) has the same scientific objects with IUGONET, namely it aims to provide an e-science infrastructure for the retrieval and access to space weather relevant data, information and value added services. It integrates 22 partners in European countries. The ESPAS also plans to adopt SPASE model for defining their metadata, but search system is different. Namely, in spite of the similarity of the data model, basic system ideas and techniques of the system and web portal are different between IUGONET and ESPAS. In order to connect the two systems/databases, we are planning to take an ontological method. The SPASE keyword vocabulary, derived from the SPASE data model shall be used as standard for the description of near-earth and space data content and context. The SPASE keyword vocabulary is modeled as Simple Knowledge Organizing System (SKOS) ontology. The SPASE keyword vocabulary also can be reused in domain-related but also cross-domain projects. The implementation of the vocabulary as ontology enables the direct integration into semantic web based structures and applications, such as linked data and the new Information System and Data Center (ISDC) data management system.

The Assessment of Digital Project Work in the EFL Classroom

ERIC Educational Resources Information Center

Berggren, Jan; Allen, Christopher

2017-01-01

This paper reports on a project aiming at describing professional practice in the assessment of collaborative digital projects among a group of inservice English as a Foreign Language (EFL) teachers within the context of a single workplace, a technologically well-resourced upper secondary school in Sweden. In a previous project (Allen &…

Evidence for disequilibrium of ortho and para hydrogen on Jupiter from Voyager IRIS measurements

NASA Technical Reports Server (NTRS)

Conrath, B. J.; Gierasch, P. J.

1983-01-01

Preliminary results of an analysis of the ortho state/para state ratio (parallel/antiparallel) for molecular H2 in the Jovian atmosphere using Voyager IR spectrometer (IRIS) data are reported. The study was undertaken to expand the understanding of the thermodynamics of a predominantly H2 atmosphere, which takes about 100 million sec to reach equilibrium. IRIS data provided 4.3/cm resolution in the 300-700/cm spectral range dominated by H2 lines. Approximately 600 spectra were examined to detect any disequilibrium between the hydrogen species. The results indicate that the ortho-para ratio is not in an equilibrium state in the upper Jovian troposphere. A thorough mapping of the para-state molecules in the upper atmosphere could therefore aid in mapping the atmospheric flowfield.

ISAMS and MLS for NASA's Upper Atmosphere Research Satellite

NASA Astrophysics Data System (ADS)

Llewellyn-Jones, D.; Dickinson, P. H. G.

1990-04-01

The primary goal of NASA's Upper Atmosphere Research Satellite (UARS), planned to be launched in 1991, is to compile data about the structure and behavior of the stratospheric ozone layer, and especially about the threat of the chlorine-based pollutants to its stablility. Two of the payload instruments, manufactured in the UK, are described: the Improved Stratospheric and Mesospheric Sounder (ISAMS), a radiometer designed to measure thermal emission from selected atmospheric constituents at the earth's limb, then making it possible to obtain nearly global coverage of the vertical distribution of temperature and composition from 80 deg S to 80 deg N latitude; and the Microwave Limb Sounder (MLS), a limb sounding radiometer, measuring atmospheric thermal emission from selected molecular spectral lines at mm wavelength, in the frequency regions of 63, 183, and 205 GHz.

Preface to Long-term trends in the upper atmosphere and ionosphere

NASA Astrophysics Data System (ADS)

Laštovička, J.; Lübken, F.-J.

2017-10-01

The anthropogenic emissions of greenhouse gases influence the atmosphere at nearly all altitudes between the ground and the topside ionosphere and upper thermosphere, thus affecting not only life on the surface, but also the space-based technological systems on which we increasingly rely. This special issue deals with long-term trends in the mesosphere, thermosphere, ionosphere, and partly also in the stratosphere, which are predominantly (but not only) caused by anthropogenic factors, particularly by the increasing concentration of carbon dioxide in the atmosphere. The special issue is based on selected papers from the 9th IAGA/ICMA/SCOSTEP workshop ;Long-Term Changes and Trends in the Atmosphere; held in September 2016 in Kühlungsborn, Germany. The 10th workshop will be held in June 2018 in Hefei, China.

Using digital photo technology to improve visualization of gastric lumen CT images

NASA Astrophysics Data System (ADS)

Pyrgioti, M.; Kyriakidis, A.; Chrysostomou, S.; Panaritis, V.

2006-12-01

In order to evaluate the gastric lumen CT images better, a new method is being applied to images using an Image Processing software. During a 12-month period, 69 patients with various gastric symptoms and 20 normal (as far as it concerns the upper gastrointestinal system) volunteers underwent computed tomography of the upper gastrointestinal system. Just before the examination the patients and the normal volunteers underwent preparation with 40 ml soda water and 10 ml gastrografin. All the CT images were digitized with an Olympus 3.2 Mpixel digital camera and further processed with an Image Processing software. The administration per os of gastrografin and soda water resulted in the distension of the stomach and consequently better visualization of all the anatomic parts. By using an Image Processing software in a PC, all the pathological and normal images of the stomach were better diagnostically estimated. We believe that the photo digital technology improves the diagnostic capacity not only of the CT image but also in MRI and probably many other imaging methods.

Upper atmospheric gravity wave details revealed in nightglow satellite imagery

PubMed Central

Miller, Steven D.; Straka, William C.; Yue, Jia; Smith, Steven M.; Alexander, M. Joan; Hoffmann, Lars; Setvák, Martin; Partain, Philip T.

2015-01-01

Gravity waves (disturbances to the density structure of the atmosphere whose restoring forces are gravity and buoyancy) comprise the principal form of energy exchange between the lower and upper atmosphere. Wave breaking drives the mean upper atmospheric circulation, determining boundary conditions to stratospheric processes, which in turn influence tropospheric weather and climate patterns on various spatial and temporal scales. Despite their recognized importance, very little is known about upper-level gravity wave characteristics. The knowledge gap is mainly due to lack of global, high-resolution observations from currently available satellite observing systems. Consequently, representations of wave-related processes in global models are crude, highly parameterized, and poorly constrained, limiting the description of various processes influenced by them. Here we highlight, through a series of examples, the unanticipated ability of the Day/Night Band (DNB) on the NOAA/NASA Suomi National Polar-orbiting Partnership environmental satellite to resolve gravity structures near the mesopause via nightglow emissions at unprecedented subkilometric detail. On moonless nights, the Day/Night Band observations provide all-weather viewing of waves as they modulate the nightglow layer located near the mesopause (∼90 km above mean sea level). These waves are launched by a variety of physical mechanisms, ranging from orography to convection, intensifying fronts, and even seismic and volcanic events. Cross-referencing the Day/Night Band imagery with conventional thermal infrared imagery also available helps to discern nightglow structures and in some cases to attribute their sources. The capability stands to advance our basic understanding of a critical yet poorly constrained driver of the atmospheric circulation. PMID:26630004

Upper atmospheric gravity wave details revealed in nightglow satellite imagery.

PubMed

Miller, Steven D; Straka, William C; Yue, Jia; Smith, Steven M; Alexander, M Joan; Hoffmann, Lars; Setvák, Martin; Partain, Philip T

2015-12-08

Gravity waves (disturbances to the density structure of the atmosphere whose restoring forces are gravity and buoyancy) comprise the principal form of energy exchange between the lower and upper atmosphere. Wave breaking drives the mean upper atmospheric circulation, determining boundary conditions to stratospheric processes, which in turn influence tropospheric weather and climate patterns on various spatial and temporal scales. Despite their recognized importance, very little is known about upper-level gravity wave characteristics. The knowledge gap is mainly due to lack of global, high-resolution observations from currently available satellite observing systems. Consequently, representations of wave-related processes in global models are crude, highly parameterized, and poorly constrained, limiting the description of various processes influenced by them. Here we highlight, through a series of examples, the unanticipated ability of the Day/Night Band (DNB) on the NOAA/NASA Suomi National Polar-orbiting Partnership environmental satellite to resolve gravity structures near the mesopause via nightglow emissions at unprecedented subkilometric detail. On moonless nights, the Day/Night Band observations provide all-weather viewing of waves as they modulate the nightglow layer located near the mesopause (∼ 90 km above mean sea level). These waves are launched by a variety of physical mechanisms, ranging from orography to convection, intensifying fronts, and even seismic and volcanic events. Cross-referencing the Day/Night Band imagery with conventional thermal infrared imagery also available helps to discern nightglow structures and in some cases to attribute their sources. The capability stands to advance our basic understanding of a critical yet poorly constrained driver of the atmospheric circulation.

Aerosol Constraints on the Atmosphere of the Hot Saturn-mass Planet WASP-49b

NASA Astrophysics Data System (ADS)

Cubillos, Patricio E.; Fossati, Luca; Erkaev, Nikolai V.; Malik, Matej; Tokano, Tetsuya; Lendl, Monika; Johnstone, Colin P.; Lammer, Helmut; Wyttenbach, Aurélien

2017-11-01

The strong, nearly wavelength-independent absorption cross section of aerosols produces featureless exoplanet transmission spectra, limiting our ability to characterize their atmospheres. Here, we show that even in the presence of featureless spectra, we can still characterize certain atmospheric properties. Specifically, we constrain the upper and lower pressure boundaries of aerosol layers, and present plausible composition candidates. We study the case of the bloated Saturn-mass planet WASP-49 b, where near-infrared observations reveal a flat transmission spectrum between 0.7 and 1.0 μm. First, we use a hydrodynamic upper-atmosphere code to estimate the pressure reached by the ionizing stellar high-energy photons at {10}-8 bar, setting the upper pressure boundary where aerosols could exist. Then, we combine HELIOS and Pyrat Bay radiative-transfer models to constrain the temperature and photospheric pressure of atmospheric aerosols, in a Bayesian framework. For WASP-49 b, we constrain the transmission photosphere (hence, the aerosol deck boundaries) to pressures above {10}-5 bar (100× solar metallicity), {10}-4 bar (solar), and {10}-3 bar (0.1× solar) as the lower boundary, and below {10}-7 bar as the upper boundary. Lastly, we compare condensation curves of aerosol compounds with the planet’s pressure-temperature profile to identify plausible condensates responsible for the absorption. Under these circumstances, we find these candidates: {{Na}}2{{S}} (at 100× solar metallicity); Cr and MnS (at solar and 0.1× solar) and forsterite, enstatite, and alabandite (at 0.1× solar).

NASA upper atmosphere research program: Research summaries, 1990 - 1991. Report to the Congress and the Environmental Protection Agency

NASA Technical Reports Server (NTRS)

1992-01-01

The objectives, status, and accomplishments of the research tasks supported under the NASA Upper Atmosphere Research Program (UARP) are presented. The topics covered include the following: balloon-borne in situ measurements; balloon-borne remote measurements; ground-based measurements; aircraft-borne measurements; rocket-borne measurements; instrument development; reaction kinetics and photochemistry; spectroscopy; stratospheric dynamics and related analysis; stratospheric chemistry, analysis, and related modeling; and global chemical modeling.

Spatial and temporal variations in infrared emissions of the upper atmosphere. 2. 15-μm carbon dioxide emission

NASA Astrophysics Data System (ADS)

Semenov, A. I.; Medvedeva, I. V.; Perminov, V. I.; Zheleznov, Yu. A.

2017-09-01

The results of rocket and satellite measurements of carbon dioxide emissions at a wavelength of 15 μm in the upper atmosphere have been systematized and analyzed. Analytical expressions describing the dependence of the altitude distribution of 15-μm CO2 emission intensity and its variation in the altitude range from 100 to 130 km on the season, latitude, and solar activity have been obtained.

A prototype Upper Atmospheric Research Collaboratory (UARC)

NASA Technical Reports Server (NTRS)

Clauer, C. R.; Atkins, D. E; Weymouth, T. E.; Olson, G. M.; Niciejewski, R.; Finholt, T. A.; Prakash, A.; Rasmussen, C. E.; Killeen, T.; Rosenberg, T. J.

1995-01-01

The National Collaboratory concept has great potential for enabling 'critical mass' working groups and highly interdisciplinary research projects. We report here on a new program to build a prototype collaboratory using the Sondrestrom Upper Atmospheric Research Facility in Kangerlussuaq, Greenland and a group of associated scientists. The Upper Atmospheric Research Collaboratory (UARC) is a joint venture of researchers in upper atmospheric and space science, computer science, and behavioral science to develop a testbed for collaborative remote research. We define the 'collaboratory' as an advanced information technology environment which enables teams to work together over distance and time on a wide variety of intellectual tasks. It provides: (1) human-to-human communications using shared computer tools and work spaces; (2) group access and use of a network of information, data, and knowledge sources; and (3) remote access and control of instruments for data acquisition. The UARC testbed is being implemented to support a distributed community of space scientists so that they have network access to the remote instrument facility in Kangerlussuaq and are able to interact among geographically distributed locations. The goal is to enable them to use the UARC rather than physical travel to Greenland to conduct team research campaigns. Even on short notice through the collaboratory from their home institutions, participants will be able to meet together to operate a battery of remote interactive observations and to acquire, process, and interpret the data.

The Relative Importance of Random Error and Observation Frequency in Detecting Trends in Upper Tropospheric Water Vapor

NASA Technical Reports Server (NTRS)

Whiteman, David N.; Vermeesch, Kevin C.; Oman, Luke D.; Weatherhead, Elizabeth C.

2011-01-01

Recent published work assessed the amount of time to detect trends in atmospheric water vapor over the coming century. We address the same question and conclude that under the most optimistic scenarios and assuming perfect data (i.e., observations with no measurement uncertainty) the time to detect trends will be at least 12 years at approximately 200 hPa in the upper troposphere. Our times to detect trends are therefore shorter than those recently reported and this difference is affected by data sources used, method of processing the data, geographic location and pressure level in the atmosphere where the analyses were performed. We then consider the question of how instrumental uncertainty plays into the assessment of time to detect trends. We conclude that due to the high natural variability in atmospheric water vapor, the amount of time to detect trends in the upper troposphere is relatively insensitive to instrumental random uncertainty and that it is much more important to increase the frequency of measurement than to decrease the random error in the measurement. This is put in the context of international networks such as the Global Climate Observing System (GCOS) Reference Upper-Air Network (GRUAN) and the Network for the Detection of Atmospheric Composition Change (NDACC) that are tasked with developing time series of climate quality water vapor data.

The relative importance of random error and observation frequency in detecting trends in upper tropospheric water vapor

NASA Astrophysics Data System (ADS)

Whiteman, David N.; Vermeesch, Kevin C.; Oman, Luke D.; Weatherhead, Elizabeth C.

2011-11-01

Recent published work assessed the amount of time to detect trends in atmospheric water vapor over the coming century. We address the same question and conclude that under the most optimistic scenarios and assuming perfect data (i.e., observations with no measurement uncertainty) the time to detect trends will be at least 12 years at approximately 200 hPa in the upper troposphere. Our times to detect trends are therefore shorter than those recently reported and this difference is affected by data sources used, method of processing the data, geographic location and pressure level in the atmosphere where the analyses were performed. We then consider the question of how instrumental uncertainty plays into the assessment of time to detect trends. We conclude that due to the high natural variability in atmospheric water vapor, the amount of time to detect trends in the upper troposphere is relatively insensitive to instrumental random uncertainty and that it is much more important to increase the frequency of measurement than to decrease the random error in the measurement. This is put in the context of international networks such as the Global Climate Observing System (GCOS) Reference Upper-Air Network (GRUAN) and the Network for the Detection of Atmospheric Composition Change (NDACC) that are tasked with developing time series of climate quality water vapor data.

[Fingers, toes and thumbs, correct digital nomenclature based on early Hebrew texts].

PubMed

Leibner, Efraim D; London, Eli; Elishoov, Ofer

2005-08-01

There is some dissonance as to the correct Hebrew terms for the digits of the extremities. Terms in common use include 'Etzba, 'Bohen' and 'Agudal'. While most agree that 'Etzba' in the singular represents the index finger, there is debate about the plural (Etzba'ot), whether it represents 'fingers' (upper extremity only) or 'digits' (upper and lower). The meaning of 'Bohen' is disputed as well, with proponents existing for it to represent: 'Toe', 'Big Toe' or 'Big Digit'. 'Agudal' is in the same predicament, with uses as 'Thumb' or 'Big Digit'. We undertook a computerized search of the Bible for these words and their derivatives in order to establish their correct use. The term 'Etzba' and its derivatives appeared numerous times in the scriptures both in singular and in plural. 'Bohen' appeared somewhat less, however, all appearances were in conjunction, viz" 'Bohen' of the hand" or " 'Bohen' of the foot". 'Agudal' was not found in our computerized search. According to the early Hebrew texts 'Etzba' in singular usually represents the index finger. However, the plural form 'Etzba'ot', corresponds to the term 'digits' and may be used both for fingers and toes. 'Bohen' is a term representing the large digit of all extremities, i.e. both 'Thumb' and 'Hallux'. Likewise, the term 'Agudal', while not appearing in the scriptures, appears in later contexts in early Hebrew texts, and also represents both the thumb and the hallux.

Titan's Upper Atmosphere from Cassini/UVIS Solar Occultations

NASA Astrophysics Data System (ADS)

Capalbo, Fernando J.; Bénilan, Yves; Yelle, Roger V.; Koskinen, Tommi T.

2015-12-01

Titan’s atmosphere is composed mainly of molecular nitrogen, methane being the principal trace gas. From the analysis of 8 solar occultations measured by the Extreme Ultraviolet channel of the Ultraviolet Imaging Spectrograph (UVIS) on board Cassini, we derived vertical profiles of N2 in the range 1100-1600 km and vertical profiles of CH4 in the range 850-1300 km. The correction of instrument effects and observational effects applied to the data are described. We present CH4 mole fractions, and average temperatures for the upper atmosphere obtained from the N2 profiles. The occultations correspond to different times and locations, and an analysis of variability of density and temperature is presented. The temperatures were analyzed as a function of geographical and temporal variables, without finding a clear correlation with any of them, although a trend of decreasing temperature toward the north pole was observed. The globally averaged temperature obtained is (150 ± 1) K. We compared our results from solar occultations with those derived from other UVIS observations, as well as studies performed with other instruments. The observational data we present confirm the atmospheric variability previously observed, add new information to the global picture of Titan’s upper atmosphere composition, variability, and dynamics, and provide new constraints to photochemical models.

Atmospheric structure and helium abundance on Saturn from Cassini/UVIS and CIRS observations

NASA Astrophysics Data System (ADS)

Koskinen, T. T.; Guerlet, S.

2018-06-01

We combine measurements from stellar occultations observed by the Cassini Ultraviolet Imaging Spectrograph (UVIS) and limb scans observed by the Composite Infrared Spectrometer (CIRS) to create empirical atmospheric structure models for Saturn corresponding to the locations probed by the occultations. The results cover multiple locations at low to mid-latitudes between the spring of 2005 and the fall of 2015. We connect the temperature-pressure (T-P) profiles retrieved from the CIRS limb scans in the stratosphere to the T-P profiles in the thermosphere retrieved from the UVIS occultations. We calculate the altitudes corresponding to the pressure levels in each case based on our best fit composition model that includes H2, He, CH4 and upper limits on H. We match the altitude structure to the density profile in the thermosphere that is retrieved from the occultations. Our models depend on the abundance of helium and we derive a volume mixing ratio of 11 ± 2% for helium in the lower atmosphere based on a statistical analysis of the values derived for 32 different occultation locations. We also derive the mean temperature and methane profiles in the upper atmosphere and constrain their variability. Our results are consistent with enhanced heating at the polar auroral region and a dynamically active upper atmosphere.

Noble gas systematics of the Skaergaard intrusion

NASA Astrophysics Data System (ADS)

Horton, F.; Farley, K. A.; Taylor, H. P.

2017-12-01

The noble gas isotopic compositions of olivines from the Skaergaard layered mafic intrusion in Greenland reveal that magmas readily exchange noble gases with their environment after emplacement. Although Skaergaard magmas are thought to have derived from the upper mantle, all of the olivine separates we analyzed have 3He/4He ratios less than that of the upper mantle ( 8 Ra, where Ra = 3He/4He of the atmosphere, 1.39 x 10-6). This suggests that crustal and/or atmospheric noble gases have contaminated all Skaergaard magmas to some extent. We obtained the highest 3He/4He ratios ( 2 Ra) from olivines found in the lowermost exposed layers of the intrusion away from the margins. Excess radiogenic 4He (indicated by Ra<1) along the margin of the intrusion indicates that noble gases from the Archean host-rock were incorporated into the cooling magma chamber, probably via magmatic assimilation. Noble gases in olivines from the upper portions of the intrusion have atmospheric isotopic compositions, but higher relative helium abundances than the atmosphere. We suggest that post-crystallization hydrothermal circulation introduced atmosphere-derived noble gases into uppermost layers of the intrusion. Such high temperature exchanges of volatiles between plutons and their immediate surroundings may help explain why so few mantle-derived rocks retain mantle-like noble gas signatures.

Fate of Ice Grains in Saturn's Ionosphere

NASA Astrophysics Data System (ADS)

Hamil, O.; Cravens, T. E.; Reedy, N. L.; Sakai, S.

2018-02-01

It has been proposed that the rings of Saturn can contribute both material (i.e., water) and energy to its upper atmosphere and ionosphere. Ionospheric models require the presence of molecular species such as water that can chemically remove ionospheric protons, which otherwise are associated with electron densities that greatly exceed those from observation. These models adopt topside fluxes of water molecules. Other models have shown that ice grains from Saturn's rings can impact the atmosphere, but the effects of these grains have not been previously studied. In the current paper, we model how ice grains deposit both material and energy in Saturn's upper atmosphere as a function of grain size, initial velocity (at the "top" of the atmosphere, defined at an altitude above the cloud tops of 3,000 km), and incident angle. Typical grain speeds are expected to be roughly 15-25 km/s. Grains with radii on the order of 1-10 nm deposit most of their energy in the altitude range of 1,700-1,900 km, and can vaporize, depending on initial velocity and impact angle, contributing water mass to the upper atmosphere. We show that grains in this radius range do not significantly vaporize in our model at initial velocities lower than about 20 km/s.

The 2011 June 23 Stellar Occultation by Pluto: Airborne and Ground Observations

NASA Astrophysics Data System (ADS)

Person, M. J.; Dunham, E. W.; Bosh, A. S.; Levine, S. E.; Gulbis, A. A. S.; Zangari, A. M.; Zuluaga, C. A.; Pasachoff, J. M.; Babcock, B. A.; Pandey, S.; Amrhein, D.; Sallum, S.; Tholen, D. J.; Collins, P.; Bida, T.; Taylor, B.; Bright, L.; Wolf, J.; Meyer, A.; Pfueller, E.; Wiedemann, M.; Roeser, H.-P.; Lucas, R.; Kakkala, M.; Ciotti, J.; Plunkett, S.; Hiraoka, N.; Best, W.; Pilger, E. J.; Micheli, M.; Springmann, A.; Hicks, M.; Thackeray, B.; Emery, J. P.; Tilleman, T.; Harris, H.; Sheppard, S.; Rapoport, S.; Ritchie, I.; Pearson, M.; Mattingly, A.; Brimacombe, J.; Gault, D.; Jones, R.; Nolthenius, R.; Broughton, J.; Barry, T.

2013-10-01

On 2011 June 23, stellar occultations by both Pluto (this work) and Charon (future analysis) were observed from numerous ground stations as well as the Stratospheric Observatory for Infrared Astronomy (SOFIA). This first airborne occultation observation since 1995 with the Kuiper Airborne Observatory resulted in the best occultation chords recorded for the event, in three visible wavelength bands. The data obtained from SOFIA are combined with chords obtained from the ground at the IRTF, the U.S. Naval Observatory Flagstaff Station, and Leeward Community College to give the detailed state of the Pluto-Charon system at the time of the event with a focus on Pluto's atmosphere. The data show a return to the distinct upper and lower atmospheric regions with a knee or kink in the light curve separating them as was observed in 1988, rather than the smoothly transitioning bowl-shaped light curves of recent years. The upper atmosphere is analyzed by fitting a model to all of the light curves, resulting in a half-light radius of 1288 ± 1 km. The lower atmosphere is analyzed using two different methods to provide results under the differing assumptions of particulate haze and a strong thermal gradient as causes for the lower atmospheric diminution of flux. These results are compared with those from past occultations to provide a picture of Pluto's evolving atmosphere. Regardless of which lower atmospheric structure is assumed, results indicate that this part of the atmosphere evolves on short timescales with results changing the light curve structures between 1988 and 2006, and then reverting these changes in 2011 though at significantly higher pressures. Throughout these changes, the upper atmosphere remains remarkably stable in structure, again except for the overall pressure changes. No evidence of onset of atmospheric collapse predicted by frost migration models is seen, and the atmosphere appears to be remaining at a stable pressure level, suggesting it should persist at this full level through New Horizon's flyby in 2015.

THE 2011 JUNE 23 STELLAR OCCULTATION BY PLUTO: AIRBORNE AND GROUND OBSERVATIONS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Person, M. J.; Bosh, A. S.; Levine, S. E.

On 2011 June 23, stellar occultations by both Pluto (this work) and Charon (future analysis) were observed from numerous ground stations as well as the Stratospheric Observatory for Infrared Astronomy (SOFIA). This first airborne occultation observation since 1995 with the Kuiper Airborne Observatory resulted in the best occultation chords recorded for the event, in three visible wavelength bands. The data obtained from SOFIA are combined with chords obtained from the ground at the IRTF, the U.S. Naval Observatory Flagstaff Station, and Leeward Community College to give the detailed state of the Pluto-Charon system at the time of the event withmore » a focus on Pluto's atmosphere. The data show a return to the distinct upper and lower atmospheric regions with a knee or kink in the light curve separating them as was observed in 1988, rather than the smoothly transitioning bowl-shaped light curves of recent years. The upper atmosphere is analyzed by fitting a model to all of the light curves, resulting in a half-light radius of 1288 {+-} 1 km. The lower atmosphere is analyzed using two different methods to provide results under the differing assumptions of particulate haze and a strong thermal gradient as causes for the lower atmospheric diminution of flux. These results are compared with those from past occultations to provide a picture of Pluto's evolving atmosphere. Regardless of which lower atmospheric structure is assumed, results indicate that this part of the atmosphere evolves on short timescales with results changing the light curve structures between 1988 and 2006, and then reverting these changes in 2011 though at significantly higher pressures. Throughout these changes, the upper atmosphere remains remarkably stable in structure, again except for the overall pressure changes. No evidence of onset of atmospheric collapse predicted by frost migration models is seen, and the atmosphere appears to be remaining at a stable pressure level, suggesting it should persist at this full level through New Horizon's flyby in 2015.« less

Investigation of feet functions of large ruminants with a decoupled model of equivalent mechanism

PubMed Central

Zhang, Qun; Ding, Xilun

2017-01-01

ABSTRACT Cloven hooves of ruminants adapt to diverse terrain, provide propulsive force and support the whole body during movement in natural environments. To reveal how the feet ensure terrain adaptability by choosing the proper configurations and terrain conditions, we model the feet of ruminants as an equivalent mechanism with flexion-extension and lateral movement decoupled. The upper part of the equivalent mechanism can flex and extend, while the lower part performs the lateral movement. Combination of the two parts can adapt to longitudinal slope (anterior-posterior) and transverse slope (medial-lateral), respectively. When one of two digits closes laterally, the workspace of the other decreases. The distal interdigital ligament between two digits limits their motion by elastic force and stores energy during movement. Differences in elastic energy variation of the ligament on different transverse slopes are characterized based on the configurations of two digits and the elastic energy between them. If the upper one of two symmetric digits is fixed, the foot landing on the grade surface (2°) shows greater capacity for absorbing energy; otherwise, level ground is the best choice for ruminants. As for the asymmetric digits, longer lateral digits enhance the optimal adaptive lateral angle. The asymmetry predisposes the feet to damage on the hard ground, which indicates soft ground is more suitable. PMID:28412713

Solar Science Digital Comic Series that promotes Science Literacy with Upper Elementary and Middle School Students

NASA Astrophysics Data System (ADS)

Kellagher, E.; Scherrer, D. K.; Buhr Sullivan, S. M.

2013-12-01

The SDO instruments (EVE, AIA and HMI) teams have created a digital comic book series for upper elementary and middle school students featuring solar science aficionados Camilla and Colours, 2 cool mascot characters. These comics may be printed or read on mobile devices and are available as a free download. Many teachers are looking for resources to use with their students via the IPad so our collaboration helps supply teachers with a great resource that teaches about solar concepts and helps dispel solar misconceptions. It doesn't come as a surprise to a lot of us, but a recent study confirms what's been theorized for years: Comics are a stronger learning tool than text books. Image-based storytelling is a powerful educational tool. Comics are probably more able to combine story and information simultaneously, more effectively and seamlessly, than almost any other medium. There's also a great potential to incorporate interactive elements into digital versions, so that more information can be presented on certain items on a page. For example, videos, animations and even historic footage and audio can be embedded into digital comics. Really, the possibilities are limited only by the creators' imaginations as to how to find new ways to create a rich experience that is interesting to explore for students. We are excited to unveil this new series of solar science comics that promotes science literacy with upper elementary and middle school students.

AVC Helps Teachers View the Atmosphere and Play in the Sand.

ERIC Educational Resources Information Center

Klaus, Christopher; Andrew, Keith; McCollum, Timothy

2003-01-01

Describes the Atmospheric Visualization Collection (AVC), part of the National Science Digital Library (NSDL) that contains an archive of weather images as well as a collection of educational material that uses the images to teach atmospheric science concepts. Discusses the potential use of this information for K-12 and undergraduate students.…

Upper limits to trace constituents in Jupiter's atmosphere from an analysis of its 5 micrometer spectrum

NASA Technical Reports Server (NTRS)

Treffers, R. R.; Larson, H. P.; Fink, U.; Gautier, T. N.

1978-01-01

A high-resolution spectrum of Jupiter at 5 micrometers recorded at the Kuiper Airborne Observatory is used to determine upper limits to the column density of 19 molecules. The upper limits to the mixing ratios of SiH4, H2S, HCN, and simple hydrocarbons are discussed with respect to current models of Jupiter's atmosphere. These upper limits are compared to expectations based upon the solar abundance of the elements. This analysis permits upper limit measurements (SiH4), or actual detections (GeH4) of molecules with mixing ratios with hydrogen as low as 10 to the minus 9th power. In future observations at 5 micrometers the sensitivity of remote spectroscopic analyses should permit the study of constituents with mixing ratios as low as 10 to the minus 10th power, which would include the hydrides of such elements as Sn and As as well as numerous organic molecules.

Ozone in the Atmosphere: I. The Upper Atmosphere.

ERIC Educational Resources Information Center

Phillips, Paul S.

1990-01-01

Research concerning the role of stratospheric ozone and the effect of chlorofluorocarbons on stratospheric ozone are discussed. The consequences of global ozone depletion are projected. The Montreal Protocol is reviewed. (CW)

Adaptive amplifier for probe diagnostics of charged-particle temperature in the upper atmosphere

NASA Astrophysics Data System (ADS)

Chkalov, V. G.

An amplifier for probe experiments in the upper atmosphere is described which is based on a linear current-voltage converter design. Specifically, the amplifier is used as the input unit in a rocket-borne ionospheric probe for the measurement of electron temperature. The range of measured currents is from 10 to the -10th to 10 to the -6th A; the amplifier current range can be shifted up or down depending on the requirements of the experiment.

Upper Atmosphere Research Report Number 21. Summary of Upper Atmosphere Rocket Research Firings

DTIC Science & Technology

1954-02-01

computer . The sky screens are essentially theodolites which view the rocket through a pair of - crossed rods which are driven closed by an electric motor...positions are electrically measured and fed into a computer . The computer continously predicts the point of impact of the rocket 411 were its thrust...Without such equipment it is neces- sary to rely on optical ’fixes’, sound ranging, or the Impact Point Computer to provide such information. In the early

Upper atmosphere research: Reaction rate and optical measurements

NASA Technical Reports Server (NTRS)

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

1990-01-01

The objective is to provide photochemical, kinetic, and spectroscopic information necessary for photochemical models of the Earth's upper atmosphere and to examine reactions or reactants not presently in the models to either confirm the correctness of their exclusion or provide evidence to justify future inclusion in the models. New initiatives are being taken in technique development (many of them laser based) and in the application of established techniques to address gaps in the photochemical/kinetic data base, as well as to provide increasingly reliable information.

Spatial and Temporal Variations of Infrared Emissions in the Upper Atmosphere. 3. 5.3-μm Nitric Oxide Emission

NASA Astrophysics Data System (ADS)

Semenov, A. I.; Medvedeva, I. V.; Perminov, V. I.

2018-03-01

The results of rocket and satellite measurements available in the literature of 5.3-μm nitric oxide emission in the upper atmosphere have been systematized and analyzed. Analytical dependences describing the height distribution of volumetric intensity of 5.3-μm emission of the NO molecule and its variations in a range of heights from 100 to 130 km as a function of the time of year, day, latitude, and solar activity have been obtained.

Hydrodynamical Modeling of Hydrogen Escape from Rocky Planets

NASA Astrophysics Data System (ADS)

Barringer, Daniel; Zugger, M.; Kasting, J.

2013-01-01

Hydrogen escape affects both the composition of primitive atmospheres of terrestrial planets and the planet’s state of oxidation. On Mars, hydrogen escape played a critical role in how long the planet remained in a warm wet state amenable to life. For both solar and extrasolar planets, hydrogen-rich atmospheres are better candidates for originating life by way of Miller-Urey-type prebiotic synthesis. However, calculating the rate of atmospheric hydrogen escape is difficult, for a number of reasons. First, the escape can be controlled either by diffusion through the homopause or by conditions in the upper atmosphere, whichever is slower. Second, both thermal and non-thermal escape mechanisms are typically important. Third, thermal escape itself can be subdivided into Jeans escape (thin upper atmosphere), and hydrodynamic escape, and hydrodynamic escape can be further subdivided into transonic escape and slower subsonic escape, depending on whether the exobase occurs above or below the sonic point. Additionally, the rate of escape for real terrestrial planet atmospheres, which are not 100% hydrogen, depends upon the concentration of infrared coolants, and upon heating and photochemistry driven largely by extreme ultraviolet (EUV) radiation. We have modified an existing 1-D model of hydrodynamic escape (F. Tian et al., JGR, 2008) to work in the high- hydrogen regime. Calculations are underway to determine hydrogen escape rates as a function of atmospheric H2 mixing ratio and the solar EUV flux. We will compare these rates with the estimated upper limit on the escape rate based on diffusion. Initial results for early Earth and Mars will later be extended to rocky exoplanets.

Pluto's Extended Atmosphere: New Horizons Alice Lyman-α Imaging

NASA Astrophysics Data System (ADS)

Retherford, Kurt D.; Gladstone, G. Randall; Stern, S. Alan; Weaver, Harold A.; Young, Leslie A.; Ennico, Kimberly A.; Olkin, Cathy B.; Cheng, Andy F.; Greathouse, Thomas K.; Hinson, David P.; Kammer, Joshua A.; Linscott, Ivan R.; Parker, Alex H.; Parker, Joel Wm.; Pryor, Wayne R.; Schindhelm, Eric; Singer, Kelsi N.; Steffl, Andrew J.; Strobel, Darrell F.; Summers, Michael E.; Tsang, Constantine C. C.; Tyler, G. Len; Versteeg, Maarten H.; Woods, William W.; Cunningham, Nathaniel J.; Curdt, Werner

2015-11-01

Pluto's upper atmosphere is expected to extend several planetary radii, proportionally more so than for any planet in our solar system. Atomic hydrogen is readily produced at lower altitudes due to photolysis of methane and transported upward to become an important constituent. The Interplanetary Medium (IPM) provides a natural light source with which to study Pluto's atomic hydrogen atmosphere. While direct solar Lyman-α emissions dominate the signal at 121.6 nm at classical solar system distances, the contribution of diffuse illumination by IPM Lyman-α sky-glow is roughly on par at Pluto (Gladstone et al., Icarus, 2015). Hydrogen atoms in Pluto's upper atmosphere scatter these bright Lyα emission lines, and detailed simulations of the radiative transfer for these photons indicate that Pluto would appear dark against the IPM Lyα background. The Pluto-Alice UV imaging spectrograph on New Horizons conducted several observations of Pluto during the encounter to search for airglow emissions, characterize its UV reflectance spectra, and to measure the radial distribution of IPM Lyα near the disk. Our early results suggest that these model predictions for the darkening of IPM Lyα with decreasing altitude being measureable by Pluto-Alice were correct. We'll report our progress toward extracting H and CH4 density profiles in Pluto's upper atmosphere through comparisons of these data with detailed radiative transfer modeling. These New Horizons findings will have important implications for determining the extent of Pluto's atmosphere and related constraints to high-altitude vertical temperature structure and atmospheric escape.This work was supported by NASA's New Horizons project.

Atmospheric forcing of the upper ocean transport in the Gulf of Mexico: From seasonal to diurnal scales

NASA Astrophysics Data System (ADS)

Judt, Falko; Chen, Shuyi S.; Curcic, Milan

2016-06-01

The 2010 Deepwater Horizon oil spill in the Gulf of Mexico (GoM) was an environmental disaster, which highlighted the urgent need to predict the transport and dispersion of hydrocarbon. Although the variability of the atmospheric forcing plays a major role in the upper ocean circulation and transport of the pollutants, the air-sea interaction on various time scales is not well understood. This study provides a comprehensive overview of the atmospheric forcing and upper ocean response in the GoM from seasonal to diurnal time scales, using climatologies derived from long-term observations, in situ observations from two field campaigns, and a coupled model. The atmospheric forcing in the GoM is characterized by striking seasonality. In the summer, the time-average large-scale forcing is weak, despite occasional extreme winds associated with hurricanes. In the winter, the atmospheric forcing is much stronger, and dominated by synoptic variability on time scales of 3-7 days associated with winter storms and cold air outbreaks. The diurnal cycle is more pronounced during the summer, when sea breeze circulations affect the coastal regions and nighttime wind maxima occur over the offshore waters. Realtime predictions from a high-resolution atmosphere-wave-ocean coupled model were evaluated for both summer and winter conditions during the Grand LAgrangian Deployment (GLAD) in July-August 2012 and the Surfzone Coastal Oil Pathways Experiment (SCOPE) in November-December 2013. The model generally captured the variability of atmospheric forcing on all scales, but suffered from some systematic errors.

Simulations of the Boreal Winter Upper Mesosphere and Lower Thermosphere With Meteorological Specifications in SD-WACCM-X

NASA Astrophysics Data System (ADS)

Sassi, Fabrizio; Siskind, David E.; Tate, Jennifer L.; Liu, Han-Li; Randall, Cora E.

2018-04-01

We investigate the benefit of high-altitude nudging in simulations of the structure and short-term variability of the upper mesosphere and lower thermosphere (UMLT) dynamical meteorology during boreal winter, specifically around the time of the January 2009 sudden stratospheric warming. We compare simulations using the Specified Dynamics, Whole Atmosphere Community Climate Model, extended version, nudged using atmospheric specifications generated by the Navy Operational Global Atmospheric Prediction System, Advanced Level Physics High Altitude. Two sets of simulations are carried out: one uses nudging over a vertical domain from 0 to 90 km; the other uses nudging over a vertical domain from 0 to 50 km. The dynamical behavior is diagnosed from ensemble mean and standard deviation of winds, temperature, and zonal accelerations due to resolved and parameterized waves. We show that the dynamical behavior of the UMLT is quite different in the two experiments, with prominent differences in the structure and variability of constituent transport. We compare the results of our numerical experiments to observations of carbon monoxide by the Atmospheric Chemistry Experiment-Fourier Transform Spectrometer to show that the high-altitude nudging is capable of reproducing with high fidelity the observed variability, and traveling planetary waves are a crucial component of the dynamics. The results of this study indicate that to capture the key physical processes that affect short-term variability (defined as the atmospheric behavior within about 10 days of a stratospheric warming) in the UMLT, specification of the atmospheric state in the stratosphere alone is not sufficient, and upper atmospheric specifications are needed.

Titan tholins formed from simuolated upper and lower atmosphere

NASA Astrophysics Data System (ADS)

Taniuchi, Toshinori; Hosogai, Tomohiro; Takano, Yoshinori; Kaneko, Takeo; Kobayashi, Kensei; Khare, Bishun; McKay, Chris

Titan, the biggest satellite of Saturn, has dense atmosphere that mainly consists of nitrogen and methane. In this study, we irradiated proton beams to the mixture of nitrogen and methane, and analyzed the structure, the chemical composition, and molecular weight of the resulting aerosols (named PI-tholins), in order to simulate possible reactions in the lower Titan atmosphere. On the other hand, magnetosphere electrons could be effective for the formation of organic molecules in the upper atmosphere of Titan. Thus we compared PI-tholin with the tholin formed by plasma discharge (named PD-tholins). A mixture of methane and nitrogen was irradiated with 3 MeV protons from a van de Graaff accelerator (Tokyo Institute of Technology). Many nitriles and nitrogen-containing heterocyclic compounds were detected by Py-GC/MS, showing that quite complex organics were formed from the simulated Titan atmosphere by proton irradiation. Microscopic observation showed that the complex organic aerosols had the structure bigger than 0.01 mm. G-value of Gly was 0.03. PD-tholins were produced by plasma discharge in 1 Torr of a mixture of methane and nitrogen by using plasma discharge facility RFX-600 (NASA Ames Research Center). Discharges were continued at 100 W for 72 hours. PD-tholins had similar chemical structures to PI-tholins. But the G-value of Gly in PD-tholins was 0.000091, which was much less thatn that in PI-tholins. It was implied that cosmic rays in the lower Titan atmosphere was much more effective to form complex organics yielding amino acids than other energies in the upper Titan atmosphere.

Computer image processing: Geologic applications

NASA Technical Reports Server (NTRS)

Abrams, M. J.

1978-01-01

Computer image processing of digital data was performed to support several geological studies. The specific goals were to: (1) relate the mineral content to the spectral reflectance of certain geologic materials, (2) determine the influence of environmental factors, such as atmosphere and vegetation, and (3) improve image processing techniques. For detection of spectral differences related to mineralogy, the technique of band ratioing was found to be the most useful. The influence of atmospheric scattering and methods to correct for the scattering were also studied. Two techniques were used to correct for atmospheric effects: (1) dark object subtraction, (2) normalization of use of ground spectral measurements. Of the two, the first technique proved to be the most successful for removing the effects of atmospheric scattering. A digital mosaic was produced from two side-lapping LANDSAT frames. The advantages were that the same enhancement algorithm can be applied to both frames, and there is no seam where the two images are joined.

Testing a Conceptual Model of Soil Emissions of Nitrous and Nitric Oxides

Treesearch

Eric A. Davidson; Michael Keller; Heather E. Erickson; Verchot NO-VALUE; Edzo Veldkamp

2000-01-01

Nitrous and nitric oxides are often studied separately by atmospheric chemists because they play such different roles in the atmosphere. N2O is a stable greenhouse gas in the lower atmosphere (the troposphere; Ramanathan et al. 1985), but it participates in photochemical reactions in the upper atmosphere (the stratosphere) that destroy ozone (Crutzen 1970). In contrast...

The Upper Atmosphere Research Satellite (UARS)

NASA Technical Reports Server (NTRS)

Reber, Carl A.

1993-01-01

The Upper Atmosphere Research Satellite (UARS) was launched by the Space Shuttle on September 12, 1991 into a near circular orbit at 585 km altitude inclined 57 degrees to the Equator. Measurements were initiated a few days later, including solar energy inputs to the atmosphere and vertical profiles of temperature, important minor gas species, and wind fields. The orbital parameters, combined with the sensor measurements characteristics, yield a measurement pattern that produces near global coverage with a duty cycle that periodically favors the Northern or the Southern Hemispheres. A few spacecraft and instrument anomalies have impacted the total amount of data obtained to date, but the overall performance of the mission has been very good.

From Hot to Hottest

NASA Image and Video Library

2017-10-31

This sequence of images shows the sun from its surface to its upper atmosphere all taken at about the same time (Oct. 27, 2017). The first shows the surface of the sun in filtered white light; the other seven images were taken in different wavelengths of extreme ultraviolet light. Note that each wavelength reveals somewhat different features. They are shown in order of temperature from the first one at 6,000 degree C. surface out to about 10 million degrees C. in the upper atmosphere. Yes, the sun's outer atmosphere is much, much hotter than the surface. Scientists are getting closer to solving the processes that generate this phenomenon. https://photojournal.jpl.nasa.gov/catalog/PIA22055

The thermosphere and ionosphere of Venus

NASA Technical Reports Server (NTRS)

Cravens, T. E.

1992-01-01

Our knowledge of the upper atmosphere and ionosphere of Venus and its interaction with the solar wind has advanced dramatically over the last decade, largely due to the data obtained during the Pioneer Venus mission and to the theoretical work that was motivated by this data. Most of this information was obtained during the period 1978 through 1981, when the periapsis of the Pioneer Venus Orbiter (PVO) was still in the measurable atmosphere. However, solar gravitational perturbations will again lower the PVO periapsis into the upper atmosphere in September 1992, prior to the destruction of the spacecraft toward the end of this year. The physics and chemistry of the thermosphere and ionosphere of Venus are reviewed.

Ionization of the Earth's Upper Atmosphere in Large Energetic Particle Events

NASA Astrophysics Data System (ADS)

Wolff, E.; Burrows, J.; Kallenrode, M.; von Koenig, M.; Kuenzi, K. F.; Quack, M.

2001-12-01

Energetic charged particles ionize the upper terrestrial atmosphere. Sofar, chemical consequences of precipitating particles have been discussed for solar protons with energies up to a few hundred MeV. We present a refined model for the interaction of energetic particles with the atmosphere based on a Monte-Carlo simulation. The model includes higher energies and other particle species, such as energetic solar electrons. Results are presented for well-known solar events, such as July 14, 2000, and are extrapolated to extremely large events, such as Carrington's white light flare in 1859, which from ice cores has been identified ass the largest impulsive NO3 event in the interval 1561 -- 1994 (McCracken et al., 2001).

The Effects of Blogging on Reading Engagement in the Upper Elementary Grades

ERIC Educational Resources Information Center

Ray, Holly Wilson

2013-01-01

With children growing up as digital natives, they have become accustomed to a fast paced, multitasking environment. In this digital landscape, children's brains learn in a parallel format, with instant information, as opposed to the traditional linear format with one skill being introduced at a time. Today's education methods used to…

Bring Your Own Device: A Digital Notebook for Undergraduate Biochemistry Laboratory Using a Free, Cross-Platform Application

ERIC Educational Resources Information Center

Van Dyke, Aaron R.; Smith-Carpenter, Jillian

2017-01-01

The majority of undergraduates own a smartphone, yet fewer than half view it as a valuable learning technology. Consequently, a digital laboratory notebook (DLN) was developed for an upper-division undergraduate biochemistry laboratory course using the free mobile application Evernote. The cloud-based DLN capitalized on the unique features of…

Training, Sharing or Cheating? Gamer Strategies to Get a Digital Upper Hand

ERIC Educational Resources Information Center

Mortensen, Torill Elvira

2010-01-01

Digital game-players devote a large amount of their time to discovering rules hidden in the code and discoverable through empirical study, experiments, and developing or rediscovering the mathematical formulae governing the code. They do this through their own independent play as they test areas, gear and abilities, through data mining using…

Fighting the Rip: Using Digital Texts in Classrooms

ERIC Educational Resources Information Center

Honan, Eileen

2009-01-01

This paper reports on a study investigating the use of digital texts in schools serving low and middle/upper socioeconomic communities. It draws on theoretical notions of rhizomes from the work of Deleuze and Guattari to explain the network of relations that are formed in classrooms, and that form the context for a set of patterns observed when…

Moving across Physical and Online Spaces: A Case Study in a Blended Primary Classroom

ERIC Educational Resources Information Center

Thibaut, Patricia; Curwood, Jen Scott; Carvalho, Lucila; Simpson, Alyson

2015-01-01

With the introduction of digital tools and online connectivity in primary schools, the shape of teaching and learning is shifting beyond the physical classroom. Drawing on the architecture of productive learning networks framework, we examine the affordances and limitations of an upper primary learning network and focus on how the digital and…

MAVEN at Mars Artist Concept

NASA Image and Video Library

2011-11-18

This artist concept depicts NASA Mars Atmosphere and Volatile EvolutioN MAVEN spacecraft near Mars. MAVEN is in development for launch in 2013 and will be the first mission devoted to understanding the Martian upper atmosphere.

Advanced Detector and Waveform Digitizer for Water Vapor DIAL Systems

NASA Technical Reports Server (NTRS)

Refaat, Tamer F.; Luck, William S., Jr.; DeYoung, Russell J.

1998-01-01

Measurement of atmospheric water vapor has become a major requirement for understanding moist-air processes. Differential absorption lidar (DIAL) is a technique best suited for the measurement of atmospheric water vapor. NASA Langley Research Center is continually developing improved DIAL systems. One aspect of current development is focused on the enhancement of a DIAL receiver by applying state-of-the-art technology in building a new compact detection system that will be placed directly on the DIAL receiver telescope. The newly developed detection system has the capability of being digitally interfaced with a simple personal computer, using a discrete input/output interface. This has the potential of transmitting digital data over relatively long distances instead of analog signals, which greatly reduces measurement noise. In this paper, we discuss some results from the new compact water vapor DIAL detection system which includes a silicon based avalanche photodiode (APD) detector, a 14-bit, 10-MHz waveform digitizer, a microcontroller and other auxiliary electronics. All of which are contained on a small printed-circuit-board. This will significantly reduce the weight and volume over the current CAMAC system and eventually will be used in a water vapor DIAL system on an unpiloted atmospheric vehicle (UAV) aircraft, or alternatively on an orbiting spacecraft.

Martian Meteorology: Determination of Large Scale Weather Patterns from Surface Measurements

NASA Technical Reports Server (NTRS)

Murphy, James R.; Haberle, Robert M.; Bridger, Alison F. C.

1998-01-01

We employed numerical modelling of the martian atmosphere, and our expertise in understanding martian atmospheric processes, to better understand the coupling between lower and upper atmosphere processes. One practical application of this work has been our involvement with the ongoing atmospheric aerobraking which the Mars Global Surveyor (MGS) spacecraft is currently undergoing at Mars. Dr. Murphy is currently a member of the Mars Global Surveyor (MGS) Aerobraking Atmospheric Advisory Group (AAG). He was asked to participate in this activity based upon his knowledge of martian atmospheric dynamical processes. Aerobraking is a process whereby a spacecraft, in an elliptical orbit, passes through the upper layers of the atmosphere (in this instance Mars). This passage through the atmosphere 'drags'upon the spacecraft, gradually reducing its orbital velocity. This has the effect, over time, of converting the elliptical orbit to a circular orbit, which is the desired mapping orbit for MGS. Carrying out aerobraking eliminates the need for carrying large amounts of fuel on the spacecraft to execute an engine burn to achieve the desired orbit. Eliminating the mass of the fuel reduces the cost of launch. Damage to one of MGS's solar panels shortly after launch has resulted in a less aggressive extended in time aerobraking phase which will not end until March, 1999. Phase I extended from Sept. 1997 through March 1998. During this time period, Dr. Murphy participated almost daily in the AAG meetings, and beginning in December 1997 lead the meeting several times per week. The leader of each of the daily AAG meetings took the results of that meeting (current state of the atmosphere, identification of any time trends or spatial patterns in upper atmosphere densities, etc.) forward to the Aerobraking Planning Group (APG) meeting, at which time the decision was made to not change MGS orbit, to lower the orbit to reach higher densities (greater 'drag'), or raise the orbit to avoid experiencing excessive, possibly damaging densities.

An Aerobraking Strategy for Determining Mars Upper Atmospheric Structure

NASA Astrophysics Data System (ADS)

Bougher, S. W.; Murphy, J. R.; Haberle, R. M.

1997-07-01

The Mars Global Surveyor (MGS) spacecraft will enter Mars orbit on Sept. 12, 1997, and thereafter undergo aerobraking for roughly 4-months. The final data-taking orbit to be achieved is sun-synchronous (2PM/2AM). An aerobraking strategy has been developed that not only will provide the walk-in capability needed to safely achieve the required Mars orbit, but also will provide a careful monitoring of the atmospheric structure. In particular, the linkage between the lower (0-100 km) and upper (100- 150 km) Mars atmospheres will be investigated. A suite of complementary measurements is planned that will probe the atmosphere over 0-150 km, including : (1) MGS Accelerometer density and inferred temperatures (100-150 km), (2) MGS Thermal Emission Spectrometer (TES) nadir (25-30 km) and limb (up to about 55 km) temperatures, (3) MGS Electron Reflectometer (ER) F1-peak heights (near 130 km), (4) ground-based microwave disk-averaged temperatures (0-70 km), and (5) Mars Pathfinder (MPF) surface meteorological data at 20 N latitude. These datasets acquired during the aerobraking phase will enable the current state of the atmosphere to be examined. Potential dust storm activity and its manifestations throughout the atmosphere can be monitored over Ls = 184 to 250. A corresponding library of coupled 3-D model simulations, based upon the NASA Ames Mars GCM and the NCAR Mars Thermospheric GCM (MTGCM), will be used to : (1) validate the current state of the Mars atmosphere, (2) investigate the various orbital, seasonal, LAT-LT-LON, and potential dust storm trends, and (3) predict the structure of the Mars atmosphere in the aerobraking corridor that is approaching in future MGS orbits. The in-situ accelerometer and ER data will eventually be used to construct a Mars empirical model covering 100-150 km. We will present a few selected GCM simulations to illustrate the expected atmospheric response to a dust storm event. In addition, we will discuss why these upper atmosphere datasets are important to future Mars missions.

Remote sensing of mesospheric winds with the High-Resolution Doppler Imager

NASA Technical Reports Server (NTRS)

Hays, Paul B.; Abreu, V. J.; Burrage, M. D.; Gell, D. A.; Grassi, H. J.; Marshall, A. R.; Morton, Y. T.; Ortland, D. A.; Skinner, W. R.; Wu, D. L.

1992-01-01

Observations of the winds in the upper atmosphere obtained with the High-Resolution Doppler Imager (HRDI) on the Upper Atmosphere Research Satellite (UARS) are discussed. This instrument is a very stable high-resolution triple-etalon Fabry-Perot interferometer, which is used to observe the slight Doppler shifts of absorption and emission lines in the O2 Atmospheric bands induced by atmospheric motions. Preliminary observations indicate that the winds in the mesosphere and lower thermosphere are a mixture of migrating and non-migrating tides, and planetary-scale waves. The mean meridional winds are dominated by the 1,1 diurnal tide which is easily extracted from the daily zonal means of the satellite observations. The daily mean zonal winds are a mixture of the diurnal tide and a zonal flow which is consistent with theoretical expectations.

The structure of Venus' middle atmosphere and ionosphere.

PubMed

Pätzold, M; Häusler, B; Bird, M K; Tellmann, S; Mattei, R; Asmar, S W; Dehant, V; Eidel, W; Imamura, T; Simpson, R A; Tyler, G L

2007-11-29

The atmosphere and ionosphere of Venus have been studied in the past by spacecraft with remote sensing or in situ techniques. These early missions, however, have left us with questions about, for example, the atmospheric structure in the transition region from the upper troposphere to the lower mesosphere (50-90 km) and the remarkably variable structure of the ionosphere. Observations become increasingly difficult within and below the global cloud deck (<50 km altitude), where strong absorption greatly limits the available investigative spectrum to a few infrared windows and the radio range. Here we report radio-sounding results from the first Venus Express Radio Science (VeRa) occultation season. We determine the fine structure in temperatures at upper cloud-deck altitudes, detect a distinct day-night temperature difference in the southern middle atmosphere, and track day-to-day changes in Venus' ionosphere.

Present state of knowledge of the upper atmosphere: An assessment report; processes that control ozone and other climatically important trace gases

NASA Technical Reports Server (NTRS)

Watson, R. T.; Geller, M. A.; Stolarski, R. S.; Hampson, R. F.

1986-01-01

The state of knowledge of the upper atmosphere was assessed as of January 1986. The physical, chemical, and radiative processes which control the spatial and temporal distribution of ozone in the atmosphere; the predicted magnitude of ozone perturbations and climate changes for a variety of trace gas scenarios; and the ozone and temperature data used to detect the presence or absence of a long term trend were discussed. This assessment report was written by a small group of NASA scientists, was peer reviewed, and is based primarily on the comprehensive international assessment document entitled Atmospheric Ozone 1985: Assessment of Our Understanding of the Processes Controlling Its Present Distribution and Change, to be published as the World Meteorological Organization Global Ozone Research and Monitoring Project Report No. 16.

Analysis and Hindcast Experiments of the 2009 Sudden Stratospheric Warming in WACCMX+DART

NASA Astrophysics Data System (ADS)

Pedatella, N. M.; Liu, H.-L.; Marsh, D. R.; Raeder, K.; Anderson, J. L.; Chau, J. L.; Goncharenko, L. P.; Siddiqui, T. A.

2018-04-01

The ability to perform data assimilation in the Whole Atmosphere Community Climate Model eXtended version (WACCMX) is implemented using the Data Assimilation Research Testbed (DART) ensemble adjustment Kalman filter. Results are presented demonstrating that WACCMX+DART analysis fields reproduce the middle and upper atmosphere variability during the 2009 major sudden stratospheric warming (SSW) event. Compared to specified dynamics WACCMX, which constrains the meteorology by nudging toward an external reanalysis, the large-scale dynamical variability of the stratosphere, mesosphere, and lower thermosphere is improved in WACCMX+DART. This leads to WACCMX+DART better representing the downward transport of chemical species from the mesosphere into the stratosphere following the SSW. WACCMX+DART also reproduces most aspects of the observed variability in ionosphere total electron content and equatorial vertical plasma drift during the SSW. Hindcast experiments initialized on 5, 10, 15, 20, and 25 January are used to assess the middle and upper atmosphere predictability in WACCMX+DART. A SSW, along with the associated middle and upper atmosphere variability, is initially predicted in the hindcast initialized on 15 January, which is ˜10 days prior to the warming. However, it is not until the hindcast initialized on 20 January that a major SSW is forecast to occur. The hindcast experiments reveal that dominant features of the total electron content can be forecasted ˜10-20 days in advance. This demonstrates that whole atmosphere models that properly account for variability in lower atmosphere forcing can potentially extend the ionosphere-thermosphere forecast range.

Propagation of Stationary Planetary Waves in the Upper Atmosphere under Different Solar Activity

NASA Astrophysics Data System (ADS)

Koval, A. V.; Gavrilov, N. M.; Pogoreltsev, A. I.; Shevchuk, N. O.

2018-03-01

Numerical modeling of changes in the zonal circulation and amplitudes of stationary planetary waves are performed with an accounting for the impact of solar activity variations on the thermosphere. A thermospheric version of the Middle/Upper Atmosphere Model (MUAM) is used to calculate the circulation in the middle and upper atmosphere at altitudes up to 300 km from the Earth's surface. Different values of the solar radio emission flux in the thermosphere are specified at a wavelength of 10.7 cm to take into account the solar activity variations. The ionospheric conductivities and their variations in latitude, longitude, and time are taken into account. The calculations are done for the January-February period and the conditions of low, medium, and high solar activity. It was shown that, during high-activity periods, the zonal wind velocities increases at altitudes exceeding 150 km and decreases in the lower layers. The amplitudes of planetary waves at high solar activity with respect to the altitude above 120 km or below 100 km, respectively, are smaller or larger than those at low activity. These differences correspond to the calculated changes in the refractive index of the atmosphere for stationary planetary waves and the Eliassen-Palm flux. Changes in the conditions for the propagation and reflection of stationary planetary waves in the thermosphere may influence the variations in their amplitudes and the atmospheric circulation, including the lower altitudes of the middle atmosphere.

Gravity Waves and Mesospheric Clouds in the Summer Middle Atmosphere: A Comparison of Lidar Measurements and Ray Modeling of Gravity Waves Over Sondrestrom, Greenland

NASA Technical Reports Server (NTRS)

Gerrard, Andrew J.; Kane, Timothy J.; Eckermann, Stephen D.; Thayer, Jeffrey P.

2004-01-01

We conducted gravity wave ray-tracing experiments within an atmospheric region centered near the ARCLITE lidar system at Sondrestrom, Greenland (67N, 310 deg E), in efforts to understand lidar observations of both upper stratospheric gravity wave activity and mesospheric clouds during August 1996 and the summer of 2001. The ray model was used to trace gravity waves through realistic three-dimensional daily-varying background atmospheres in the region, based on forecasts and analyses in the troposphere and stratosphere and climatologies higher up. Reverse ray tracing based on upper stratospheric lidar observations at Sondrestrom was also used to try to objectively identify wave source regions in the troposphere. A source spectrum specified by reverse ray tracing experiments in early August 1996 (when atmospheric flow patterns produced enhanced transmission of waves into the upper stratosphere) yielded model results throughout the remainder of August 1996 that agreed best with the lidar observations. The model also simulated increased vertical group propagation of waves between 40 km and 80 km due to intensifying mean easterlies, which allowed many of the gravity waves observed at 40 km over Sondrestrom to propagate quasi-vertically from 40-80 km and then interact with any mesospheric clouds at 80 km near Sondrestrom, supporting earlier experimentally-inferred correlations between upper stratospheric gravity wave activity and mesospheric cloud backscatter from Sondrestrom lidar observations. A pilot experiment of real-time runs with the model in 2001 using weather forecast data as a low-level background produced less agreement with lidar observations. We believe this is due to limitations in our specified tropospheric source spectrum, the use of climatological winds and temperatures in the upper stratosphere and mesosphere, and missing lidar data from important time periods.

Intraseasonal variability of upper-ocean currents and photosynthetic primary production along the U.S. west coast associated with the Madden-Julian Oscillation

NASA Astrophysics Data System (ADS)

Barrett, B.; Davies, A. R.; Steppe, C. N.; Hackbarth, C.

2017-12-01

In the first part of this study, time-lagged composites of upper-ocean currents from February to May of 1993-2016 were binned by active phase of the leading atmospheric mode of intraseasonal variability, the Madden-Julian Oscillation (MJO). Seven days after the convectively active phase of the MJO enters the tropical Indian Ocean, anomalously strong south-southeastward upper-ocean currents are observed along the majority of U.S. west coast. Seven days after the convectively active phase enters the tropical western Pacific Ocean, upper-ocean current anomalies reverse along the U.S. west coast, with weaker southward flow. A physical pathway to the ocean was found for both of these: (a) tropical MJO convection modulates upper-tropospheric heights and circulation over the Pacific Ocean; (b) those anomalous atmospheric heights adjust the strength and position of the Aleutian Low and Hawaiian High; (c) surface winds change in response to the adjusted atmospheric pressure patterns; and (d) those surface winds project onto upper-ocean currents. In the second part of this study, we investigated if the MJO modulated intraseasonal variability of surface wind forcing and upper-ocean currents projected onto phytoplankton abundance along the U.S. west coast. Following a similar methodology, time-lagged, level 3 chlorophyll-a satellite products (a proxy for photosynthetic primary production) were binned by active MJO phase and analyzed for statistical significance using the Student's t test. Results suggest that intraseasonal variability of biological production along the U.S. west coast may be linked to the MJO, particularly since the time scale of the life cycle of phytoplankton is similar to the time scale of the MJO.

Estimation of the global climate effect of brown carbon

NASA Astrophysics Data System (ADS)

Zhang, A.; Wang, Y.; Zhang, Y.; Weber, R. J.; Song, Y.

2017-12-01

Carbonaceous aerosols significantly affect global radiative forcing and climate through absorption and scattering of sunlight. Black carbon (BC) and brown carbon (BrC) are light-absorbing carbonaceous aerosols. The global distribution and climate effect of BrC is uncertain. A recent study suggests that BrC absorption is comparable to BC in the upper troposphere over biomass burning region and that the resulting heating tends to stabilize the atmosphere. Yet current climate models do not include proper treatments of BrC. In this study, we derived a BrC global biomass burning emission inventory from Global Fire Emissions Database 4 (GFED4) and developed a BrC module in the Community Atmosphere Model version 5 (CAM5) of Community Earth System Model (CESM) model. The model simulations compared well to BrC observations of the Studies of Emissions, Atmospheric Composition, Clouds and Climate Coupling by Regional Surveys (SEAC4RS) and Deep Convective Clouds and Chemistry Project (DC-3) campaigns and includes BrC bleaching. Model results suggested that BrC in the upper troposphere due to convective transport is as important an absorber as BC globally. Upper tropospheric BrC radiative forcing is particularly significant over the tropics, affecting the atmosphere stability and Hadley circulation.

Poleward upgliding Siberian atmospheric rivers over sea ice heat up Arctic upper air.

PubMed

Komatsu, Kensuke K; Alexeev, Vladimir A; Repina, Irina A; Tachibana, Yoshihiro

2018-02-13

We carried out upper air measurements with radiosondes during the summer over the Arctic Ocean from an icebreaker moving poleward from an ice-free region, through the ice edge, and into a region of thick ice. Rapid warming of the Arctic is a significant environmental issue that occurs not only at the surface but also throughout the troposphere. In addition to the widely accepted mechanisms responsible for the increase of tropospheric warming during the summer over the Arctic, we showed a new potential contributing process to the increase, based on our direct observations and supporting numerical simulations and statistical analyses using a long-term reanalysis dataset. We refer to this new process as "Siberian Atmospheric Rivers (SARs)". Poleward upglides of SARs over cold air domes overlying sea ice provide the upper atmosphere with extra heat via condensation of water vapour. This heating drives increased buoyancy and further strengthens the ascent and heating of the mid-troposphere. This process requires the combination of SARs and sea ice as a land-ocean-atmosphere system, the implication being that large-scale heat and moisture transport from the lower latitudes can remotely amplify the warming of the Arctic troposphere in the summer.

Arctic Strato-Mesospheric Temperature and Wind Variations

NASA Technical Reports Server (NTRS)

Schmidlin, F. J.; Goldberg, R. A.

2004-01-01

Upper stratosphere and mesosphere rocket measurements are actively used to investigate interaction between the neutral, electrical, and chemical atmospheres and between lower and upper layers of these regions. Satellite temperature measurements from HALOE and from inflatable falling spheres complement each other and allow illustrations of the annual cycle to 85 km altitude. Falling sphere wind and temperature measurements reveal variability that differs as a function of altitude, location, and time. We discuss the state of the Arctic atmosphere during the summer 2002 (Andoya, Norway) and winter 2003 (ESRANGE, Sweden) campaigns of MaCWAVE. Balloon-borne profiles to 30 km altitude and sphere profiles between 50 and 90 km show unique small-scale structure. Nonetheless, there are practical implications that additional measurements are very much needed to complete the full vertical profile picture. Our discussion concentrates on the distribution of temperature and wind and their variability. However, reliable measurements from other high latitude NASA programs over a number of years are available to help properly calculate mean values and the distribution of the individual measurements. Since the available rocket data in the Arctic's upper atmosphere are sparse the results we present are basically a snapshot of atmospheric structure.

Observations of Highly Variable Deuterium in the Martian Upper Atmosphere

NASA Astrophysics Data System (ADS)

Clarke, John T.; Mayyasi-Matta, Majd A.; Bhattacharyya, Dolon; Chaufray, Jean-Yves; Chaffin, Michael S.; Deighan, Justin; Schneider, Nicholas M.; Jain, Sonal; Jakosky, Bruce

2017-10-01

One of the key pieces of evidence for historic high levels of water on Mars is the present elevated ratio of deuterium/hydrogen (D/H) in near-surface water. This can be explained by the loss of large amounts of water into space, with the lighter H atoms escaping faster than D atoms. Understanding the specific physical processes and controlling factors behind the present escape of H and D is the key objective of the MAVEN IUVS echelle channel. This knowledge can then be applied to an accurate extrapolation back in time to understand the water history of Mars. Observations of D in the martian upper atmosphere over the first martian year of the MAVEN mission have shown highly variable amounts of D, with a short-lived maximum just after perihelion and during southern summer. The timing and nature of this increase provide constraints on its possible origin. These results will be presented and compared with other measurements of the upper atmosphere of Mars.

Characteristics of skylight at the zenith during twilight as indicators of atmospheric turbidity. 2: Intensity and color ratio.

PubMed

Coulson, K L

1981-05-01

This is the second of two papers based on an extensive series of measurements of the intensity and polarization of light from the zenith sky during periods of twilight made at an altitude of 3400 m on the island of Hawaii. Part 1 dealt with the skylight polarization; part 2 is on the measured intensity and quantities derived from the intensity. The principal results are that (1) the polarization and intensity of light from the zenith during twilight are sensitive indicators of the existence of turbid layers in the stratosphere and upper troposphere, and (2) at least at Mauna Loa primary scattering of the sunlight incident on the upper atmosphere during twilight is strongly dominant over secondary or multiple scattering at wavelengths beyond ~0.60microm, whereas this is much less true at shorter wavelengths. It is suggested that the development and general use of a simple twilight polarimeter would greatly facilitate determinations of turbidity in the upper layers of the atmosphere.

Upper atmosphere research satellite program. [to study the chemistry energetics, and dynamics

NASA Technical Reports Server (NTRS)

Huntress, W. T., Jr.

1978-01-01

A satellite program to conduct research on the chemistry, energetics, and dynamics of the upper atmosphere was developed. The scientific goals of the Upper Atmospheric Research Program, the program requirements, and the approach toward meeting those requirements are outlined. An initial series of two overlapping spacecraft missions is described. Both spacecraft are launched and recovered by the STS, one in the winter of 1983 at a 56 deg inclination, and the other a year later at a 70 deg inclination. The duration of each mission is 18 months, and each carries instruments to make global measurements of the temperature, winds, composition, irradation, and radiance in the stratosphere, mesosphere, and lower thermosphere between the tropopause and 120 km altitude. The program requires a dedicated ground-based data system and a science team organization that leads to a strong interaction between the experiments and theory. The program includes supportive observations from other platforms such as rockets, balloons, and the Spacelab.

Determination of design and operation parameters for upper atmospheric research instrumentation to yield optimum resolution with deconvolution

NASA Technical Reports Server (NTRS)

Ioup, George E.; Ioup, Juliette W.

1991-01-01

The final report for work on the determination of design and operation parameters for upper atmospheric research instrumentation to yield optimum resolution with deconvolution is presented. Papers and theses prepared during the research report period are included. Among all the research results reported, note should be made of the specific investigation of the determination of design and operation parameters for upper atmospheric research instrumentation to yield optimum resolution with deconvolution. A methodology was developed to determine design and operation parameters for error minimization when deconvolution is included in data analysis. An error surface is plotted versus the signal-to-noise ratio (SNR) and all parameters of interest. Instrumental characteristics will determine a curve in this space. The SNR and parameter values which give the projection from the curve to the surface, corresponding to the smallest value for the error, are the optimum values. These values are constrained by the curve and so will not necessarily correspond to an absolute minimum in the error surface.

A Study on Various Meteoroid Disintegration Mechanisms as Observed from the Resolute Bay Incoherent Scatter Radar (RISR)

NASA Technical Reports Server (NTRS)

Malhotra, A.; Mathews, J. D.

2011-01-01

There has been much interest in the meteor physics community recently regarding the form that meteoroid mass flux arrives in the upper atmosphere. Of particular interest are the relative roles of simple ablation, differential ablation, and fragmentation in the meteoroid mass flux observed by the Incoherent Scatter Radars (ISR). We present here the first-ever statistical study showing the relative contribution of the above-mentioned three mechanisms. These are also one of the first meteor results from the newly-operational Resolute Bay ISR. These initial results emphasize that meteoroid disintegration into the upper atmosphere is a complex process in which all the three above-mentioned mechanisms play an important role though fragmentation seems to be the dominant mechanism. These results prove vital in studying how meteoroid mass is deposited in the upper atmosphere which has important implications to the aeronomy of the region and will also contribute in improving current meteoroid disintegration/ablation models.

An analysis of Solar Mesospheric Explorer temperatures for the upper stratosphere and mesosphere

NASA Technical Reports Server (NTRS)

Clancy, R. Todd; Rusch, David W.

1993-01-01

We proposed to analyze Solar Mesosphere Explorer (SME) limb profiles of Rayleigh scattered solar flux at wavelengths of 304, 313, and 443 nm to retrieve atmospheric temperature profiles over the 40-65 km altitude region. These temperatures can be combined with the previous analysis of SME 296 nm limb radiances to construct a monthly average climatology of atmospheric temperatures over the 40-90 km, upper stratosphere-mesosphere region, with approximately 4 km vertical resolution. We proposed to investigate the detailed nature of the global temperature structure of this poorly measured region, based on these 1982-1986 SME temperatures. The average vertical structure of temperatures between the stratopause and mesopause has never been determined globally with vertical resolution sufficient to retrieve even scale-height structures. Hence, the SME temperatures provided a unique opportunity to study the detailed thermal structure of the mesosphere, in advance of Upper Atmosphere Research Satellite (UARS) measurements and the Thermosphere Ionosphere Mesosphere Energy and Dynamics (TIMED) mission.

Building a new space weather facility at the National Observatory of Athens

NASA Astrophysics Data System (ADS)

Kontogiannis, Ioannis; Belehaki, Anna; Tsiropoula, Georgia; Tsagouri, Ioanna; Anastasiadis, Anastasios; Papaioannou, Athanasios

2016-01-01

The PROTEAS project has been initiated at the Institute of Astronomy, Astrophysics, Space Applications and Remote Sensing (IAASARS) of the National Observatory of Athens (NOA). One of its main objectives is to provide observations, processed data and space weather nowcasting and forecasting products, designed to support the space weather research community and operators of commercial and industrial systems. The space weather products to be released by this facility, will be the result of the exploitation of ground-based, as well as space-borne observations and of model results and tools already available or under development by IAASARS researchers. The objective will be achieved through: (a) the operation of a small full-disk solar telescope to conduct regular observations of the Sun in the H-alpha line; (b) the construction of a database with near real-time solar observations which will be available to the community through a web-based facility (HELIOSERVER); (c) the development of a tool for forecasting Solar Energetic Particle (SEP) events in relation to observed solar eruptive events; (d) the upgrade of the Athens Digisonde with digital transceivers and the capability of operating in bi-static link mode and (e) the sustainable operation of the European Digital Upper Atmosphere Server (DIAS) upgraded with additional data sets integrated in an interface with the HELIOSERVER and with improved models for the real-time quantification of the effects of solar eruptive events in the ionosphere.

Derivation of the horizontal wind field in the polar mesopause region by using successive images of noctilucent clouds observed by a color digital camera in Iceland

NASA Astrophysics Data System (ADS)

Suzuki, H.; Yamashita, R.

2017-12-01

It is important to quantify amplitude of turbulent motion to understand the energy and momentum budgets and distribution of minor constituents in the upper mesosphere. In particular, to know the eddy diffusion coefficient of minor constituents which are locally and impulsively produced by energetic particle precipitations in the polar mesopause is one of the most important subjects in the upper atmospheric science. One of the straight methods to know the amplitude of the eddy motion is to measure the wind field with both spatial and temporal domain. However, observation technique satisfying such requirements is limited in this region. In this study, derivation of the horizontal wind field in the polar mesopause region by tracking the motion of noctilucent clouds (NLCs) is performed. NLC is the highest cloud in the Earth which appears in a mesopause region during summer season in both polar regions. Since the vertical structure of the NLC is sufficiently thin ( within several hundred meters in typical), the apparent horizontal motion observed from ground can be regarded as the result of transportation by the horizontal winds at a single altitude. In this presentation, initial results of wind field derivation by tracking a motion of noctilucent clouds (NLC) observed by a ground-based color digital camera in Iceland is reported. The procedure for wind field estimation consists with 3 steps; (1) projects raw images to a geographical map (2) enhances NLC structures by using FFT method (3) determines horizontal velocity vectors by applying template matching method to two sequential images. In this talk, a result of the wind derivation by using successive images of NLC with 3 minutes interval and 1.5h duration observed on the night of Aug 1st, 2013 will be reported as a case study.

Non-thermal hydrogen atoms in the terrestrial upper thermosphere.

PubMed

Qin, Jianqi; Waldrop, Lara

2016-12-06

Model predictions of the distribution and dynamical transport of hydrogen atoms in the terrestrial atmosphere have long-standing discrepancies with ultraviolet remote sensing measurements, indicating likely deficiencies in conventional theories regarding this crucial atmospheric constituent. Here we report the existence of non-thermal hydrogen atoms that are much hotter than the ambient oxygen atoms in the upper thermosphere. Analysis of satellite measurements indicates that the upper thermospheric hydrogen temperature, more precisely the mean kinetic energy of the atomic hydrogen population, increases significantly with declining solar activity, contrary to contemporary understanding of thermospheric behaviour. The existence of hot hydrogen atoms in the upper thermosphere, which is the key to reconciling model predictions and observations, is likely a consequence of low atomic oxygen density leading to incomplete collisional thermalization of the hydrogen population following its kinetic energization through interactions with hot atomic or ionized constituents in the ionosphere, plasmasphere or magnetosphere.

Non-thermal hydrogen atoms in the terrestrial upper thermosphere

PubMed Central

Qin, Jianqi; Waldrop, Lara

2016-01-01

Model predictions of the distribution and dynamical transport of hydrogen atoms in the terrestrial atmosphere have long-standing discrepancies with ultraviolet remote sensing measurements, indicating likely deficiencies in conventional theories regarding this crucial atmospheric constituent. Here we report the existence of non-thermal hydrogen atoms that are much hotter than the ambient oxygen atoms in the upper thermosphere. Analysis of satellite measurements indicates that the upper thermospheric hydrogen temperature, more precisely the mean kinetic energy of the atomic hydrogen population, increases significantly with declining solar activity, contrary to contemporary understanding of thermospheric behaviour. The existence of hot hydrogen atoms in the upper thermosphere, which is the key to reconciling model predictions and observations, is likely a consequence of low atomic oxygen density leading to incomplete collisional thermalization of the hydrogen population following its kinetic energization through interactions with hot atomic or ionized constituents in the ionosphere, plasmasphere or magnetosphere. PMID:27922018

Dynamics of Venus Upper Atmosphere from Infrared Heterodyne Spectroscopy of CO2

NASA Astrophysics Data System (ADS)

Sornig, Manuela; Sonnabend, G.; Kroetz, P. J.; Stupar, D.; Schieder, R. T.; Sandor, B.; Clancy, T.

2009-09-01

Wind velocities in the upper atmosphere of Venus can be determined from Doppler-shifts of narrow non-LTE emission lines of CO2 at 10 µm with an precision of up to 10 m/s using infrared heterodyne spectroscopy. Such observations address a narrow altitude region in the upper atmosphere of Venus around 110 km. At the University of Cologne we developed a Tunable Infrared Heterodyne Spectrometer (THIS) capable of accomplishing such ground-based measurements of planetary atmospheres. Beside high spectral resolution (R>107) this method also guarantees high spatial resolution on the planet (FOV of 1.7 arcsec on an apparent diameter of Venus of 20 arcsec using the McMath-Pierce-Solar Telescope on Kitt Peak). Over the last two years we observed wind velocities with THIS at several characteristic orbital positions of Venus. In May and November 2007 Venus was at its maximum eastern and western elongation, respectively. This specific observing geometry with an illumination of about 50% of the apparent planetary disk allows us to detect dominantly the superrotation component in Venus upper atmosphere. So far results indicate surprisingly low wind velocities of a few tens of m/s with almost no wind at the equator and highest values at mid latitudes. Observations close to inferior conjunction have been accomplished in March and April 2009. This observing geometry gives wind velocities consisting of a combination of the superrotation and the SS-AS flow close to the terminator. Data analysis is still ongoing but first analysis indicate a higher wind velocity than found in the results from maximum elongation. We are going to present data and results from these runs as well as results from a first coordinated observation between our infrared group and JCMT sub-mm observations in March 2009.

Rarefied gas dynamic simulation of transfer and escape in the Pluto-Charon system

NASA Astrophysics Data System (ADS)

Hoey, William A.; Yeoh, Seng Keat; Trafton, Laurence M.; Goldstein, David B.; Varghese, Philip L.

2017-05-01

We apply the direct simulation Monte Carlo rarefied gas dynamic technique to simulations of Pluto's rarefied upper atmosphere motivated by the need to better understand New Horizons (NH) data. We present a novel three-dimensional DSMC model of the atmosphere that spans from several hundred km below the exobase - where continuum flow transitions to the rarefied regime - to fully free-molecular flow hundreds of thousands of km from Pluto's center. We find molecular collisions in Pluto's upper atmosphere to be significant in shaping the flowfield, both by promoting flux from the plutonian exobase to Charon and by increasing the proportion of that flux generated on the exobase's anti-Charon hemisphere. Our model accounts for the gravitational fields of both Pluto and Charon, the centripetal and Coriolis forces due to the rotation of Pluto in our reference frame, and the presence of Charon as a temporary sink for impacting particles. Using this model, we analyze the escape processes of N2 and CH4 from Pluto across different solar heating conditions, and evaluate the three-dimensional structure of the upper plutonian atmosphere, including gas transfer to and deposition on Charon. We find results consistent with the NH-determined escape rate, upper atmospheric temperature, and lack of a detectable Charon atmosphere. Gas-transfer structures are noted in a binary atmospheric configuration, including preferential deposition of material from Pluto's escaping atmosphere onto Charon's leading hemisphere that peaks at 315° E on the equator. As the moon gravitationally focuses incident flow, a high density structure forms in its wake. If molecules are permitted to escape from Charon in diffuse reflections from its surface, a returning flux forms to Pluto's exobase, preferentially directed toward its trailing hemisphere. Charon is capable of supporting a thin atmosphere at column densities as high as 1.5 × 1017 m-2 in simulations with a plutonian exobase condition similar to the NH encounter. Results computed from a fit to the NH encounter exobase (Gladstone et al., 2016) predict a system escape rate of 7 × 1025 CH4 s-1 in close agreement with those reported by NH (Bagenal et al., 2016; Gladstone et al., 2016), and a net depositional flux to Charon of 2 × 1024 s-1, of which ∼98% is methane.

Characterizing the UV environment of GJ1214b

NASA Astrophysics Data System (ADS)

Desert, Jean-Michel

2010-09-01

The recent detection of a super-Earth transiting a nearby low-mass star GJ1214 {Charbonneau et al., 2009} has opened the door to testing the predictions of low mass planet atmosphere theories. Theoretical models predict that low mass planets are likely to exist with atmospheres that can vary widely in their composition and structure. Some super-Earths may be able to retain massive hydrogen-rich atmospheres. Others might never accumulate hydrogen or experience significant escape of lightweight elements, resulting in atmospheres more like those of the terrestrial planets in our Solar System. Planets which orbit close to their parent stars, such as close-in hot-Jupiters and super-Earths, are exposed to strong XEUV flux that influence their atmospheres and may trigger atmospheric escape processes. This phenomenon, which shapes planetary atmospheres, determines the evolution of the planet. This can also dramatically enhance the detectability of a heavily irradiated hydrogen atmosphere when the planet transits in front of its parent star. We propose to use HST/STIS/G140M to determine the intensity and variability of the Lyman-alpha chromospheric emission line and provide observational constraints to super-Earth atmospheric models. We propose to coordinate this measurement with a planetary transit in order to detect large upper atmospheric signatures if present. This short measurement also enables us to determine whether a larger program dedicated to upper atmospheric study is feasible for a following cycle.

Metals from deep atmosphere to exosphere in hot-Jupiters

NASA Astrophysics Data System (ADS)

Lecavelier des Etangs, Alain

2017-08-01

With STIS/UV observations we detected magnesium atoms at high altitude in the atmosphere of the hot-Jupiter HD209458b, probing lower regions in the atmosphere than previously done with Lyman-alpha observations (Vidal-Madjar et al. 2013). With the present program, we will search for magnesium and other heavy species in escaping atmospheres of 2 giant planets orbiting hot A and F-type stars: WASP-94Ab and WASP-33b.The observations will provide unprecedented information on the physical conditions (velocity, temperature, and density) in the upper atmosphere of these two hot-Jupiters. Targets have been selected for the expected high significance level of the atmospheric detections (>10 sigma). These exoplanets present favorable configuration for upper atmosphere observations because of the combination of high escape rates and large spatial extensions of the magnesium clouds surrounding them. The atmospheric signatures of the magnesium and other metals are therefore expected to be easily detectable. Moreover, the two selected exoplanets have highly different equilibrium temperatures, below and above the MgSiO3 condensation temperature. Consequently, because the metals observed in the escaping flow originate from deeper in the atmosphere where haze can condensate, the observations will constrain the physical processes taking place in the clouds that cannot be observed directly.

NASA/MSFC FY-80 Atmospheric Processes Research Review

NASA Technical Reports Server (NTRS)

Turner, R. E. (Compiler)

1980-01-01

Three general areas of research were discussed: Global Weather, Upper Atmosphere, and Severe Storms and Local Weather. Research project summaries, in narrative outline form, stating objectives, significant accomplishments, and recommendations for future research are presented.

NASA/MSFC FY-81 Atmospheric Processes Research Review

NASA Technical Reports Server (NTRS)

Turner, R. E. (Compiler)

1981-01-01

Progress in ongoing research programs and future plans for satellite investigations into global weather, upper atmospheric phenomena, and severe storms and local weather are summarized. Principle investigators and publications since June 1980 are listed.

Deceleration of Mars Science Laboratory in Martian Atmosphere, Artist Concept

NASA Image and Video Library

2011-10-03

This artist concept depicts the interaction of NASA Mars Science Laboratory spacecraft with the upper atmosphere of Mars during the entry, descent and landing of the Curiosity rover onto the Martian surface.

UA-ICON - A non-hydrostatic global model for studying gravity waves from the troposphere to the thermosphere

NASA Astrophysics Data System (ADS)

Borchert, Sebastian; Zängl, Günther; Baldauf, Michael; Zhou, Guidi; Schmidt, Hauke; Manzini, Elisa

2017-04-01

In numerical weather prediction as well as climate simulations, there are ongoing efforts to raise the upper model lid, acknowledging the possible influence of middle and upper atmosphere dynamics on tropospheric weather and climate. As the momentum deposition of gravity waves (GWs) is responsible for key features of the large scale flow in the middle and upper atmosphere, the upward model extension has put GWs in the focus of atmospheric research needs. The Max Planck Institute for Meteorology (MPI-M) and the German Weather Service (DWD) have been developing jointly the non-hydrostatic global model ICON (Zängl et al, 2015) which features a new dynamical core based on an icosahedral grid. The extension of ICON beyond the mesosphere, where most GWs deposit their momentum, requires, e.g., relaxing the shallow-atmosphere and other traditional approximations as well as implementing additional physical processes that are important to the upper atmosphere. We would like to present aspects of the model development and its evaluation, and first results from a simulation of a period of the DEEPWAVE campaign in New Zealand in 2014 (Fritts et al, 2016) using grid nesting up to a horizontal mesh size of about 1.25 km. This work is part of the research unit: Multi-Scale Dynamics of Gravity Waves (MS-GWaves: sub-project GWING, https://ms-gwaves.iau.uni-frankfurt.de/index.php), funded by the German Research Foundation. Fritts, D.C. and Coauthors, 2016: "The Deep Propagating Gravity Wave Experiment (DEEPWAVE): An airborne and ground-based exploration of gravity wave propagation and effects from their sources throughout the lower and middle atmosphere". Bull. Amer. Meteor. Soc., 97, 425 - 453, doi:10.1175/BAMS-D-14-00269.1 Zängl, G., Reinert, D., Ripodas, P., Baldauf, M., 2015: "The ICON (ICOsahedral Non-hydrostatic) modelling framework of DWD and MPI-M: Description of the non-hydrostatic dynamical core". Quart. J. Roy. Met. Soc., 141, 563 - 579, doi:10.1002/qj.2378

The statistical properties of vortex flows in the solar atmosphere

NASA Astrophysics Data System (ADS)

Wedemeyer, Sven; Kato, Yoshiaki; Steiner, Oskar

2015-08-01

Rotating magnetic field structures associated with vortex flows on the Sun, also known as “magnetic tornadoes”, may serve as waveguides for MHD waves and transport mass and energy upwards through the atmosphere. Magnetic tornadoes may therefore potentially contribute to the heating of the upper atmospheric layers in quiet Sun regions.Magnetic tornadoes are observed over a large range of spatial and temporal scales in different layers in quiet Sun regions. However, their statistical properties such as size, lifetime, and rotation speed are not well understood yet because observations of these small-scale events are technically challenging and limited by the spatial and temporal resolution of current instruments. Better statistics based on a combination of high-resolution observations and state-of-the-art numerical simulations is the key to a reliable estimate of the energy input in the lower layers and of the energy deposition in the upper layers. For this purpose, we have developed a fast and reliable tool for the determination and visualization of the flow field in (observed) image sequences. This technique, which combines local correlation tracking (LCT) and line integral convolution (LIC), facilitates the detection and study of dynamic events on small scales, such as propagating waves. Here, we present statistical properties of vortex flows in different layers of the solar atmosphere and try to give realistic estimates of the energy flux which is potentially available for heating of the upper solar atmosphere

TITAN’S UPPER ATMOSPHERE FROM CASSINI/UVIS SOLAR OCCULTATIONS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Capalbo, Fernando J.; Bénilan, Yves; Yelle, Roger V.

2015-12-01

Titan’s atmosphere is composed mainly of molecular nitrogen, methane being the principal trace gas. From the analysis of 8 solar occultations measured by the Extreme Ultraviolet channel of the Ultraviolet Imaging Spectrograph (UVIS) on board Cassini, we derived vertical profiles of N{sub 2} in the range 1100–1600 km and vertical profiles of CH{sub 4} in the range 850–1300 km. The correction of instrument effects and observational effects applied to the data are described. We present CH{sub 4} mole fractions, and average temperatures for the upper atmosphere obtained from the N{sub 2} profiles. The occultations correspond to different times and locations,more » and an analysis of variability of density and temperature is presented. The temperatures were analyzed as a function of geographical and temporal variables, without finding a clear correlation with any of them, although a trend of decreasing temperature toward the north pole was observed. The globally averaged temperature obtained is (150 ± 1) K. We compared our results from solar occultations with those derived from other UVIS observations, as well as studies performed with other instruments. The observational data we present confirm the atmospheric variability previously observed, add new information to the global picture of Titan’s upper atmosphere composition, variability, and dynamics, and provide new constraints to photochemical models.« less

BOREAS AFM-5 Level-2 Upper Air Network Standard Pressure Level Data

NASA Technical Reports Server (NTRS)

Barr, Alan; Hrynkiw, Charmaine; Hall, Forrest G. (Editor); Newcomer, Jeffrey A. (Editor); Smith, David E. (Technical Monitor)

2000-01-01

The BOREAS AFM-5 team collected and processed data from the numerous radiosonde flights during the project. The goals of the AFM-05 team were to provide large-scale definition of the atmosphere by supplementing the existing AES aerological network, both temporally and spatially. This data set includes basic upper-air parameters interpolated at 0.5 kiloPascal increments of atmospheric pressure from data collected from the network of upper-air stations during the 1993, 1994, and 1996 field campaigns over the entire study region. The data are contained in tabular ASCII files. The data files are available on a CD-ROM (see document number 20010000884) or from the Oak Ridge National Laboratory (ORNL) Distributed Active Archive Center (DAAC).

Long-period humidity variability in the Arctic atmosphere from upper-air observations

NASA Astrophysics Data System (ADS)

Agurenko, A.; Khokhlova, A.

2014-12-01

Under climate change, atmospheric water content also tends to change. This gives rise to changes in the amount of moisture transferred, clouds and precipitation, as well as in hydrological regime. This work analyzes seasonal climatic characteristics of precipitated water in the Arctic atmosphere, by using 1972-2011 data from 55 upper-air stations located north of 60°N. Regions of maximum and minimum mean values and variability trends are determined. In the summer, water amount is shown to increase in nearly the whole of the latitudinal zone. The comparison with the similar characteristics of reanalysis obtained by the other authors shows a good agreement. Time variation in the atmosphere moisture transport crossing 70°N, which is calculated from observation data, is presented and compared with model results. The work is supported by the joint EC ERA.Net RUS and Russian Fundamental Research Fund Project "Arctic Climate Processes Linked Through the Circulation of the Atmosphere" (ACPCA) (project 12-05-91656-ЭРА_а).

Data Needs and Modeling of the Upper Atmosphere

NASA Astrophysics Data System (ADS)

Brunger, M. J.; Campbell, L.

2007-04-01

We present results from our enhanced statistical equilibrium and time-step codes for atmospheric modeling. In particular we use these results to illustrate the role of electron-driven processes in atmospheric phenomena and the sensitivity of the model results to data inputs such as integral cross sections, dissociative recombination rates and chemical reaction rates.

NASA/MSFC FY-83 Atmospheric Processes Research Review

NASA Technical Reports Server (NTRS)

Turner, R. E. (Compiler)

1983-01-01

The atmospheric processes research program was reviewed. Research tasks sponsored by the NASA Office of Space Science and Applications, Earth Sciences and Applications Division in the areas of upper atmosphere, global weather, and mesoscale processes are discussed. The are: the research project summaries, together with the agenda and other information about the meeting.

Future monitoring of charged particle energy deposition into the upper atmosphere and comments on possible relationships between atmospheric phenomena and solar and/or geomagnetic activity

NASA Technical Reports Server (NTRS)

Williams, D. J.; Grubb, R. N.; Evans, D. S.; Sauer, H. H.

1975-01-01

Monitoring of earth's atmosphere was conducted for several years utilizing the ITOS series of low-altitude, polar-orbiting weather satellites. A space environment monitoring package was included in these satellites to perform measurements of a portion of earth's charged particle environment. The charged particle observations proposed for the low-altitude weather satellite TIROS N, are described which will provide the capability of routine monitoring of the instantaneous total energy deposition into the upper atmosphere by the precipitation of charged particles from higher altitudes. Such observations may be of use in future studies of the relationships between geomagnetic activity and atmospheric weather pattern developments. Estimates are given to assess the potential importance of this type of energy deposition. Discussion and examples are presented illustrating the importance of distinguishing between solar and geomagnetic activity as possible causative sources. Such differentiation is necessary because of the widely different spatial and time scales involved in the atmospheric energy input resulting from these various sources of activity.

STOCHASTIC TRANSIENTS AS A SOURCE OF QUASI-PERIODIC PROCESSES IN THE SOLAR ATMOSPHERE

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yuan, Ding; Walsh, Robert W.; Su, Jiangtao

2016-06-01

Solar dynamics and turbulence occur at all heights of the solar atmosphere and could be described as stochastic processes. We propose that finite-lifetime transients recurring at a certain place could trigger quasi-periodic processes in the associated structures. In this study, we developed a mathematical model for finite-lifetime and randomly occurring transients, and found that quasi-periodic processes with periods longer than the timescale of the transients, are detectable intrinsically in the form of trains. We simulate their propagation in an empirical solar atmospheric model with chromosphere, transition region, and corona. We found that, due to the filtering effect of the chromosphericmore » cavity, only the resonance period of the acoustic resonator is able to propagate to the upper atmosphere; such a scenario is applicable to slow magnetoacoustic waves in sunspots and active regions. If the thermal structure of the atmosphere is less wild and acoustic resonance does not take place, the long-period oscillations could propagate to the upper atmosphere. Such a case would be more likely to occur in polar plumes.« less

Distribution of normal superficial ocular vessels in digital images.

PubMed

Banaee, Touka; Ehsaei, Asieh; Pourreza, Hamidreza; Khajedaluee, Mohammad; Abrishami, Mojtaba; Basiri, Mohsen; Daneshvar Kakhki, Ramin; Pourreza, Reza

2014-02-01

To investigate the distribution of different-sized vessels in the digital images of the ocular surface, an endeavor which may provide useful information for future studies. This study included 295 healthy individuals. From each participant, four digital photographs of the superior and inferior conjunctivae of both eyes, with a fixed succession of photography (right upper, right lower, left upper, left lower), were taken with a slit lamp mounted camera. Photographs were then analyzed by a previously described algorithm for vessel detection in the digital images. The area (of the image) occupied by vessels (AOV) of different sizes was measured. Height, weight, fasting blood sugar (FBS) and hemoglobin levels were also measured and the relationship between these parameters and the AOV was investigated. These findings indicated a statistically significant difference in the distribution of the AOV among the four conjunctival areas. No significant correlations were noted between the AOV of each conjunctival area and the different demographic and biometric factors. Medium-sized vessels were the most abundant vessels in the photographs of the four investigated conjunctival areas. The AOV of the different sizes of vessels follows a normal distribution curve in the four areas of the conjunctiva. The distribution of the vessels in successive photographs changes in a specific manner, with the mean AOV becoming larger as the photos were taken from the right upper to the left lower area. The AOV of vessel sizes has a normal distribution curve and medium-sized vessels occupy the largest area of the photograph. Copyright © 2013 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.

Effectiveness of Three-Dimensional Digital Animation in Teaching Human Anatomy in an Authentic Classroom Context

ERIC Educational Resources Information Center

Hoyek, Nady; Collet, Christian; Di Rienzo, Franck; De Almeida, Mickael; Guillot, Aymeric

2014-01-01

Three-dimensional (3D) digital animations were used to teach the human musculoskeletal system to first year kinesiology students. The purpose of this study was to assess the effectiveness of this method by comparing two groups from two different academic years during two of their official required anatomy examinations (trunk and upper limb…

Analysis of synchronous digital-modulation schemes for satellite communication

NASA Technical Reports Server (NTRS)

Takhar, G. S.; Gupta, S. C.

1975-01-01

The multipath communication channel for space communications is modeled as a multiplicative channel. This paper discusses the effects of multiplicative channel processes on the symbol error rate for quadrature modulation (QM) digital modulation schemes. An expression for the upper bound on the probability of error is derived and numerically evaluated. The results are compared with those obtained for additive channels.

Model simulations of the impact of energetic particle precipitation onto the upper and middle atmosphere

NASA Astrophysics Data System (ADS)

Wieters, Nadine; Sinnhuber, Miriam; Winkler, Holger; Berger, Uwe; Maik Wissing, Jan; Stiller, Gabriele; Funke, Bernd; Notholt, Justus

Solar eruptions and geomagnetic storms can produce fluxes of high-energy protons and elec-trons, so-called Solar Energetic Particle Events, which can enter the Earth's atmosphere espe-cially in polar regions. These particle fluxes primarily cause ionisation and excitation in the upper atmosphere, and thereby the production of HOx and NOx species, which are catalysts for the reduction of ozone. To simulate such particle events, ionisation rates, calculated by the Atmospheric Ionization Module Osnabrück AIMOS (University of Osnabrück), have been implemented into the Bremen 3D Chemistry and Transport Model. To cover altitudes up to the mesopause, the model is driven by meteorological data, provided by the Leibniz-Institute Middle Atmosphere Model LIMA (IAP Kühlungsborn). For several electron and proton events during the highly solar-active period 2003/2004, model calculations have been carried out. To investigate the accordance of modeled to observed changes for atmospheric constituents like NO, NO2 , HNO3 , N2 O5 , ClO, and O3 , results of these calculations will be compared to measurements by the Michelson Interferometer for Passive Atmospheric Sounding MIPAS (ENVISAT) instrument. Computed model results and comparisons with measurements will be presented.

Digital Data from the Great Sand Dunes and Poncha Springs Aeromagnetic Surveys, South-Central Colorado

USGS Publications Warehouse

Drenth, B.J.; Grauch, V.J.S.; Bankey, Viki; New Sense Geophysics, Ltd.

2009-01-01

This report contains digital data, image files, and text files describing data formats and survey procedures for two high-resolution aeromagnetic surveys in south-central Colorado: one in the eastern San Luis Valley, Alamosa and Saguache Counties, and the other in the southern Upper Arkansas Valley, Chaffee County. In the San Luis Valley, the Great Sand Dunes survey covers a large part of Great Sand Dunes National Park and Preserve and extends south along the mountain front to the foot of Mount Blanca. In the Upper Arkansas Valley, the Poncha Springs survey covers the town of Poncha Springs and vicinity. The digital files include grids, images, and flight-line data. Several derivative products from these data are also presented as grids and images, including two grids of reduced-to-pole aeromagnetic data and data continued to a reference surface. Images are presented in various formats and are intended to be used as input to geographic information systems, standard graphics software, or map plotting packages.

Atmospheric Dust in the Upper Colorado River Basin: Integrated Analysis of Digital Imagery, Total Suspended Particulate, and Meteorological Data

NASA Astrophysics Data System (ADS)

Urban, F. E.; Reynolds, R. L.; Neff, J. C.; Fernandez, D. P.; Reheis, M. C.; Goldstein, H.; Grote, E.; Landry, C.

2012-12-01

Improved measurement and observation of dust emission and deposition in the American west would advance understanding of (1) landscape conditions that promote or suppress dust emission, (2) dynamics of dryland and montane ecosystems, (3) premature melting of snow cover that provides critical water supplies, and (4) possible effects of dust on human health. Such understanding can be applied to issues of land management, water-resource management, as well as the safety and well-being of urban and rural inhabitants. We have recently expanded the scope of particulate measurement in the Upper Colorado River basin through the establishment of total-suspended-particulate (TSP) measurement stations located in Utah and Colorado with bi-weekly data (filter) collection, along with protocols for characterizing dust-on-snow (DOS) layers in Colorado mountains. A sub-network of high-resolution digital cameras has been co-located with several of the TSP stations, as well as at other strategic locations. These real-time regional dust-event detection cameras are internet-based and collect digital imagery every 6-15 minutes. Measurements of meteorological conditions to support these collections and observations are provided partly by CLIM-MET stations, four of which were deployed in 1998 in the Canyonlands (Utah) region. These stations provide continuous, near real-time records of the complex interaction of wind, precipitation, vegetation, as well as dust emission and deposition, in different land-use settings. The complementary datasets of dust measurement and observation enable tracking of individual regional dust events. As an example, the first DOS event of water year 2012 (Nov 5, 2011), as documented at Senator Beck Basin, near Silverton, Colorado, was also recorded by the camera at Island-in-the-Sky (200 km to the northwest), as well as in aeolian activity and wind data from the Dugout Ranch CLIM-MET station (170 km to the west-northwest). At these sites, strong winds and the presence of dense dust preceded precipitation. Similar conditions and results were recorded in many subsequent water year 2012 DOS events, with complementary quantification in TSP dust-flux records. Spring 2012 included several intense dry (no associated precipitation) regional dust events that occurred after snowmelt. These events during May 25-26, especially, are clearly evident in the imagery, TSP, and local meteorological data.

Pluto’s Atmosphere from the 23 June 2011 Stellar Occultation: Airborne and Ground Observations

NASA Astrophysics Data System (ADS)

Person, Michael J.; Bosh, A. S.; Levine, S. E.; Gulbis, A. A. S.; Zangari, A. M.; Zuluaga, C. A.; Dunham, E. W.; Pasachoff, J. M.; Babcock, B. A.; Pandey, S.; Armhein, D.; Sallum, S.; Tholen, D. J.; Collins, P.; Bida, T.; Taylor, B.; Wolf, J.; Meyer, A.; Pfueller, E.; Wiedermann, M.; Roesser, H.; Lucas, R.; Kakkala, M.; Ciotti, J.; Plunkett, S.; Hiraoka, N.; Best, W.; Pilger, E. L.; Miceli, M.; Springmann, A.; Hicks, M.; Thackeray, B.; Emery, J.; Rapoport, S.; Ritchie, I.

2012-10-01

The double stellar occultation by Pluto and Charon of 2011 June 23 was observed from numerous ground stations as well as the Stratospheric Observatory for Infrared Astronomy (SOFIA). This first airborne occultation observation since 1995 resulted in the best occultation chords recorded for the event, in three optical wavelength bands. The data obtained from SOFIA were combined with chords obtained from the ground at the IRTF (including a full spectral light curve), the USNO--Flagstaff Station, and Leeward Community College to give a detailed profile of Pluto’s atmosphere. The data show a return to the distinct upper and lower atmospheric regions with a knee, or kink in the light curves separating them as was observed in 1988 (Millis et al. 1993), rather than the smoothly transitioning bowl-shaped light curves of recent years (Elliot et al. 2007). We analyze the upper atmosphere by fitting a model to all of the light curves obtained, resulting in a half-light radius of 1288 ± 1 km. We analyze the lower atmosphere with two different methods to provide results under the separate assumptions of particulate haze and a strong thermal gradient. Results indicate that the lower atmosphere evolves on short seasonal timescales, changing between 1988 and 2006, and then returning to approximately the 1988 state in 2011, though at significantly higher pressures. Throughout these changes, the upper atmosphere remains remarkably stable in structure, again excepting the overall pressure changes. No evidence of the onset of atmospheric collapse predicted by frost migration models is yet seen, and the atmosphere appears to be remaining at a stable pressure level. This work was supported in part by NASA Planetary Astronomy grants to MIT (NNX10AB27G) and Williams College (NNX08AO50G, NNH11ZDA001N), as well as grants from USRA (#8500-98-003) and Ames Research (#NAS2-97-01) to Lowell Observatory.

Electrodynamics on extrasolar giant planets

DOE Office of Scientific and Technical Information (OSTI.GOV)

Koskinen, T. T.; Yelle, R. V.; Lavvas, P.

2014-11-20

Strong ionization on close-in extrasolar giant planets (EGPs) suggests that their atmospheres may be affected by ion drag and resistive heating arising from wind-driven electrodynamics. Recent models of ion drag on these planets, however, are based on thermal ionization only and do not include the upper atmosphere above the 1 mbar level. These models are also based on simplified equations of resistive magnetohydrodynamics that are not always valid in extrasolar planet atmospheres. We show that photoionization dominates over thermal ionization over much of the dayside atmosphere above the 100 mbar level, creating an upper ionosphere dominated by ionization of Hmore » and He and a lower ionosphere dominated by ionization of metals such as Na, K, and Mg. The resulting dayside electron densities on close-in exoplanets are higher than those encountered in any planetary ionosphere of the solar system, and the conductivities are comparable to the chromosphere of the Sun. Based on these results and assumed magnetic fields, we constrain the conductivity regimes on close-in EGPs and use a generalized Ohm's law to study the basic effects of electrodynamics in their atmospheres. We find that ion drag is important above the 10 mbar level where it can also significantly alter the energy balance through resistive heating. Due to frequent collisions of the electrons and ions with the neutral atmosphere, however, ion drag is largely negligible in the lower atmosphere below the 10 mbar level for a reasonable range of planetary magnetic moments. We find that the atmospheric conductivity decreases by several orders of magnitude in the night side of tidally locked planets, leading to a potentially interesting large-scale dichotomy in electrodynamics between the day and night sides. A combined approach that relies on UV observations of the upper atmosphere, phase curve and Doppler measurements of global dynamics, and visual transit observations to probe the alkali metals can potentially be used to constrain electrodynamics in the future.« less

Oxidation and evaporation of sulfur species at atmospheric entry of iron sulfide fine particles

NASA Astrophysics Data System (ADS)

Isobe, H.; Murozono, K.

2017-12-01

Micrometeorites have the most abundant flux in current accumulation of planetary materials to the Earth. Micrometeorites are heated and reacted with upper atmosphere at atmospheric entry. Evaporation of meteoritic materials, especially sulfur species, may have environmental effect at upper atmosphere (e.g. Court and Sephton, 2011; Tomkins et al., 2016). Troilite is typical FeS phase in chondritic meteorites. In this study, quick heating and cooling experiments of FeS reagent particles were carried out with a fine particles free falling apparatus with controlled gas flow (Isobe and Gondo, 2013). Starting material reagent is inhomogeneous mixture of troilite, iron oxide and iron metal. Oxygen fugacity was controlled to FMQ +1.5 log unit. Maximum temperature of the particles was higher than 1400°C for approximately 0.5 seconds. Run products with rounded shape and smooth surface show the particles were completely melted. Chemical compositions of particles analyzed on cross sections are generally well homogenized from inhomogeneous starting materials by complete melting. Molar ratios of Fe in melted regions are close to 0.5, while compositions of S and O are various. Varieties of S and O compositions show various degree of oxidation and evaporation of sulfur. Distribution of compositions of melted regions in Fe-S-O system is plotted in liquidus compositions of FeO and FeS saturated melt. Troilite in micrometeorite is melted and oxidized by atmospheric entry. Compositions of FeS melt in fine spherules are following Fe-S-O phase relations even in a few seconds. Molar ratios of Fe in melt are close to 0.5, while compositions of S and O are various. Varieties of S and O compositions show various degree of oxidation and evaporation of sulfur. Evaporation of sulfur from meteoritic materials in atmospheric entry heating may depend on oxygen fugacity of the upper atmosphere. Sulfur supply from meteoritic materials to atmosphere may be limited on planets with oxygen-free atmosphere.

Venus Atmospheric Maneuverable Platform (VAMP) - A Low Cost Venus Exploration Concept

NASA Astrophysics Data System (ADS)

Lee, G.; Polidan, R. S.; Ross, F.

2015-12-01

The Northrop Grumman Aerospace Systems and L-Garde team has been developing an innovative mission concept: a long-lived, maneuverable platform to explore the Venus upper atmosphere. This capability is an implementation of our Lifting Entry Atmospheric Flight (LEAF) system concept, and the Venus implementation is called the Venus Atmospheric Maneuverable Platform (VAMP). The VAMP concept utilizes an ultra-low ballistic coefficient (< 50 Pa), semi-buoyant aircraft that deploys prior to entering the Venus atmosphere, enters without an aeroshell, and provides a long-lived (months to a year) maneuverable vehicle capable of carrying science instruments to explore the Venus upper atmosphere. In this presentation we provide an update on the air vehicle design and a low cost pathfinder mission concept that can be implemented in the near-term. The presentation also provides an overview of our plans for future trade studies, analyses, and prototyping to advance and refine the concept. We will discuss the air vehicle's entry concepts of operations (CONOPs) and atmospheric science operations. We will present a strawman concept of a VAMP pathfinder, including ballistic coefficient, planform area, percent buoyancy, wing span, vehicle mass, power supply, propulsion, materials considerations, structural elements, and instruments accommodation. In this context, we will discuss the following key factors impacting the design and performance of VAMP: Entry into the Venus atmosphere, including descent profile, heating rate, total heat load, stagnation, and acreage temperatures Impact of maximum altitude on air vehicle design and entry heating Candidate thermal protection system (TPS) requirements We will discuss the interdependencies of the above factors and the manner in which the VAMP pathfinder concept's characteristics affect the CONOPs and the science objectives. We will show how the these factors provide constraints as well as enable opportunities for novel long duration scientific studies of the Venus upper atmosphere that support Venus science goals. We will also discuss how the VAMP platform itself can facilitate some of these science measurements.

Modeling Planetary Atmospheric Energy Deposition By Energetic Ions

NASA Astrophysics Data System (ADS)

Parkinson, Christopher; Bougher, Stephen; Gronoff, Guillaume; Barthelemy, Mathieu

2016-07-01

The structure, dynamics, chemistry, and evolution of planetary upper atmospheres are in large part determined by the available sources of energy. In addition to the solar EUV flux, the solar wind and solar energetic particle (SEP) events are also important sources. Both of these particle populations can significantly affect an atmosphere, causing atmospheric loss and driving chemical reactions. Attention has been paid to these sources from the standpoint of the radiation environment for humans and electronics, but little work has been done to evaluate their impact on planetary atmospheres. At unmagnetized planets or those with crustal field anomalies, in particular, the solar wind and SEPs of all energies have direct access to the atmosphere and so provide a more substantial energy source than at planets having protective global magnetic fields. Additionally, solar wind and energetic particle fluxes should be more significant for planets orbiting more active stars, such as is the case in the early history of the solar system for paleo-Venus and Mars. Therefore quantification of the atmospheric energy input from the solar wind and SEP events is an important component of our understanding of the processes that control their state and evolution. We have applied a full Lorentz motion particle transport model to study the effects of particle precipitation in the upper atmospheres of Mars and Venus. Such modeling has been previously done for Earth and Mars using a guiding center precipitation model. Currently, this code is only valid for particles with small gyroradii in strong uniform magnetic fields. There is a clear necessity for a Lorentz formulation, hence, a systematic study of the ionization, excitation, and energy deposition has been conducted, including a comparison of the influence relative to other energy sources (namely EUV photons). The result is a robust examination of the influence of energetic ion transport on the Venus and Mars upper atmosphere which will be discussed in this presentation.

Preliminary Results on Mars and the Siding Spring Meteor Shower from MAVEN's Imaging UV Spectrograph

NASA Astrophysics Data System (ADS)

Schneider, Nicholas

2015-04-01

The MAVEN mission to Mars is designed to study the upper atmosphere and its response to external drivers, searching for clues to the cause of long-term atmospheric loss. MAVEN carries the Imaging UV Spectrograph (IUVS) for remote sensing studies of the atmosphere through vertical scans from the limb through the corona, UV imaging of the planet and stellar occultations. Each observational mode has successfully observed the spectral features and spatial distributions as intended, confirming and expanding our understanding of the Mars upper atmosphere as observed by the Mariner spacecraft and Mars Express. Furthermore, IUVS witnessed the aftermath of an intense meteor shower on Mars caused by Comet Siding Spring. For a period of many hours, the planet's UV spectrum was dominated by emission from ionized magnesium deposited by meteor ablation in the upper atmosphere. Initial results from the originally-planned Mars observations include: • Significant persistent structures in the thermospheric day glow emissions, dependent primarily on solar zenith angle, along with significant variability on daily timescales; • Nitric oxide nightglow and low-level auroral emissions of substantially greater nightside extent than previously seen; • Confirmation of N2 emission in the VK band, as first reported by MEX/SPICAM; • The first vertical profiles of the D/H ratio in the atmosphere and their evolution with Mars season; • The most complete maps and vertical profiles of H, C and O in the Mars corona; • The first global snapshot of the middle atmosphere obtained by a day-long stellar occultation campaign; • Global ozone maps spanning several months of seasonal evolution. Other results from the missions's preliminary phases will be included.

Magnetic Shocks and Substructures Excited by Torsional Alfvén Wave Interactions in Merging Expanding Flux Tubes

NASA Astrophysics Data System (ADS)

Snow, B.; Fedun, V.; Gent, F. A.; Verth, G.; Erdélyi, R.

2018-04-01

Vortex motions are frequently observed on the solar photosphere. These motions may play a key role in the transport of energy and momentum from the lower atmosphere into the upper solar atmosphere, contributing to coronal heating. The lower solar atmosphere also consists of complex networks of flux tubes that expand and merge throughout the chromosphere and upper atmosphere. We perform numerical simulations to investigate the behavior of vortex-driven waves propagating in a pair of such flux tubes in a non-force-free equilibrium with a realistically modeled solar atmosphere. The two flux tubes are independently perturbed at their footpoints by counter-rotating vortex motions. When the flux tubes merge, the vortex motions interact both linearly and nonlinearly. The linear interactions generate many small-scale transient magnetic substructures due to the magnetic stress imposed by the vortex motions. Thus, an initially monolithic tube is separated into a complex multithreaded tube due to the photospheric vortex motions. The wave interactions also drive a superposition that increases in amplitude until it exceeds the local Mach number and produces shocks that propagate upward with speeds of approximately 50 km s‑1. The shocks act as conduits transporting momentum and energy upward, and heating the local plasma by more than an order of magnitude, with a peak temperature of approximately 60,000 K. Therefore, we present a new mechanism for the generation of magnetic waveguides from the lower solar atmosphere to the solar corona. This wave guide appears as the result of interacting perturbations in neighboring flux tubes. Thus, the interactions of photospheric vortex motions is a potentially significant mechanism for energy transfer from the lower to upper solar atmosphere.

Structure of the middle atmosphere of Venus

NASA Astrophysics Data System (ADS)

Zasova, Ludmila

Middle atmosphere of Venus (55-100 km), its mesosphere, is the important layer of atmosphere, where 70 % of the solar energy is absorbed. Most of this absorption takes place in the upper clouds in the altitude range 58-68 km in the spectral range 0.32-0.5 µm. It leads to generation of the thermal tides, playing important role in support of the superrotation. In the frame of COSPAR model VIRA (ASR, 11,1985) the model of the thermal structure of the middle atmosphere was constructed for 5 latitude ranges, based mainly on the Pioneer Venus ORO and OIR data. Using Venera-15 Fourier Spectrometry data, which allow to retrieve the temperature and aerosol profiles in a self consistent way from each spectrum, we enable to update the model of the middle atmosphere, including the local time variation of the temperature for VIRA latitude ranges (Cosmic Research, 44, 4, 2006). From Venera-15 data it was shown that variation of temperature in the middle atmosphere is well described by thermal tides with harmonics 1, 1/2, 1/3, 1/4 Venusian day, the amplitudes and phases of which depend on latitude and altitude. The model of the upper clouds (VIRA) may also be updated using Venera-15 data. It was shown that the main latitude trend is the decreasing of the upper cloud boundary from 68 km at low latitudes to 60-62 km at high latitudes. Local time variation has a solar related dependence: 1 and 1/2 day components were revealed. Venus Express continues to obtain a lot of data, which may be used for the improvement of the model of the middle atmosphere and the clouds.

STRATOSPHERIC TEMPERATURES AND WATER LOSS FROM MOIST GREENHOUSE ATMOSPHERES OF EARTH-LIKE PLANETS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kasting, James F.; Kopparapu, Ravi K.; Chen, Howard, E-mail: jfk4@psu.edu, E-mail: hwchen@bu.edu

A radiative-convective climate model is used to calculate stratospheric temperatures and water vapor concentrations for ozone-free atmospheres warmer than that of modern Earth. Cold, dry stratospheres are predicted at low surface temperatures, in agreement with recent 3D calculations. However, at surface temperatures above 350 K, the stratosphere warms and water vapor becomes a major upper atmospheric constituent, allowing water to be lost by photodissociation and hydrogen escape. Hence, a moist greenhouse explanation for loss of water from Venus, or some exoplanet receiving a comparable amount of stellar radiation, remains a viable hypothesis. Temperatures in the upper parts of such atmospheresmore » are well below those estimated for a gray atmosphere, and this factor should be taken into account when performing inverse climate calculations to determine habitable zone boundaries using 1D models.« less

The Escaping Upper Atmospheres of Hot Jupiters

NASA Astrophysics Data System (ADS)

Davidson, Eric; Jones, Gabrielle; Uribe, Ana; Carson, Joseph

2017-01-01

Hot Jupiters are massive gaseous planets which orbit closely to their parent star. The strong stellar irradiation at these small orbital separations causes the temperature of the upper atmosphere of the planet to rise. This can cause the planet's atmosphere to escape into space, creating an exoplanet outflow. We ascertained which factors determine the presence and structure of these outflows by creating one dimensional simulations of the density, pressure, velocity, optical depth, and neutral fraction of hot Jupiter atmospheres. This was done for planets of masses and radii ranging from 0.5-1.5 Mj and 0.5-1.5 Rj. We found the outflow rate to be highest for a planet of 0.5 Mj and 1.5 Rj at 5.3×10-14 Mj/Yr. We also found that the higher the escape velocity, the lower the chance of the planet having an outflow.

Atmospheric products from the Upper Atmosphere Research Satellite (UARS)

NASA Technical Reports Server (NTRS)

Ahmad, Suraiya P.; Johnson, James E.; Jackman, Charles H.

2003-01-01

This paper provides information on the products available at the NASA Goddard Earth Sciences (GES) Distributed Active Archive Center (DAAC) from the Upper Atmosphere Research Satellite (UARS) mission. The GES DAAC provides measurements from the primary UARS mission, which extended from launch in September 1991 through September 2001. The ten instruments aboard UARS provide measurements of atmospheric trace gas species, dynamical variables, solar irradiance input, and particle energy flux. All standard Level 3 UARS products from all ten instruments are offered free to the public and science user community. The Level 3 data are geophysical parameters, which have been transformed into a common format and equally spaced along the measurement trajectory. The UARS data have been reprocessed several times over the years following improvements to the processing algorithms. The UARS data offered from the GES DAAC are the latest versions of each instrument. The UARS data may be accessed through the GES DAAC website at

Forgotten Digital Tourniquet: Salvage of an Ischaemic Finger by Application of Medicinal Leeches

PubMed Central

Durrant, C; Townley, WA; Ramkumar, S; Khoo, CTK

2006-01-01

Individual finger tourniquets are appropriate to the management of a wide range of conditions presenting to an accident and emergency department. They are simpler and more comfortable to use than upper arm pneumatic tourniquets and commercially available digital tourniquets are not readily available in the accident and emergency unit. However, if a finger tourniquet is overlooked, ischaemia of the digit results, and gangrene may follow if the problem is not defused early enough, leading to potential disaster.1–3 We present one case where a digit was salvaged after 4 days of tourniquet application, using medicinal leeches. PMID:17002851

Digital enhancement of sub-quality bitemark photographs.

PubMed

Karazalus, C P; Palmbach, T T; Lee, H C

2001-07-01

Digital enhancement software was used to enhance bitemark photographs. This enhancement technique improved the resolution of the bitemark images. Lucis was the software program utilized in this study and case applications. First, this technique was applied on known bitemark images to evaluate the potential effectiveness of this digital enhancement method. Subsequently, Lucis was utilized on two separate unsolved cases involving enhancement of bitemark evidence. One case involved a severely beaten infant with a bitemark on the upper thigh. The second case involves a bitemark observed on the breast of a female sexual assault strangulation victim. In both cases, bitemark images were significantly improved after digital enhancement.

29 CFR Appendix A to Subpart B of... - Compliance Assistance Guidelines for Confined and Enclosed Spaces and Other Dangerous Atmospheres

Code of Federal Regulations, 2010 CFR

2010-07-01

... interchangeably in fire science literature. Section 1915.11(b)Definition of “Upper explosive limit.” The terms upper flammable limit (UFL) and upper explosive limit (UEL) are used interchangeably in fire science... life and is adequate for entry. However, any oxygen level greater than 20.8 percent by volume should...

29 CFR Appendix A to Subpart B of... - Compliance Assistance Guidelines for Confined and Enclosed Spaces and Other Dangerous Atmospheres

Code of Federal Regulations, 2011 CFR

2011-07-01

... interchangeably in fire science literature. Section 1915.11(b)Definition of “Upper explosive limit.” The terms upper flammable limit (UFL) and upper explosive limit (UEL) are used interchangeably in fire science... life and is adequate for entry. However, any oxygen level greater than 20.8 percent by volume should...

New project to support scientific collaboration electronically

NASA Astrophysics Data System (ADS)

Clauer, C. R.; Rasmussen, C. E.; Niciejewski, R. J.; Killeen, T. L.; Kelly, J. D.; Zambre, Y.; Rosenberg, T. J.; Stauning, P.; Friis-Christensen, E.; Mende, S. B.; Weymouth, T. E.; Prakash, A.; McDaniel, S. E.; Olson, G. M.; Finholt, T. A.; Atkins, D. E.

A new multidisciplinary effort is linking research in the upper atmospheric and space, computer, and behavioral sciences to develop a prototype electronic environment for conducting team science worldwide. A real-world electronic collaboration testbed has been established to support scientific work centered around the experimental operations being conducted with instruments from the Sondrestrom Upper Atmospheric Research Facility in Kangerlussuaq, Greenland. Such group computing environments will become an important component of the National Information Infrastructure initiative, which is envisioned as the high-performance communications infrastructure to support national scientific research.

Spatial and temporal variations in infrared emissions of the upper atmosphere. 1. Atomic oxygen (λ 63 μm) emission

NASA Astrophysics Data System (ADS)

Semenov, A. I.; Medvedeva, I. V.; Perminov, V. I.; Khomich, V. Yu.

2016-09-01

Rocket and balloon measurement data on atomic-oxygen (λ 63 µm) emission in the upper atmosphere are presented. The data from the longest (1989-2003) period of measurements of the atomic-oxygen (λ 63 µm) emission intensity obtained by spectral instruments on sounding balloons at an altitude of 38 km at midlatitudes have been systematized and analyzed. Regularities in diurnal and seasonal variations in the intensity of this emission, as well as in its relation with solar activity, have been revealed.

Three-dimensional dental arch changes of patients submitted to orthodontic-surgical treatment for correction of Class II malocclusion

PubMed Central

Peixoto, Adriano Porto; Pinto, Ary dos Santos; Garib, Daniela Gamba; Gonçalves, João Roberto

2014-01-01

Introduction This study assessed the three-dimensional changes in the dental arch of patients submitted to orthodontic-surgical treatment for correction of Class II malocclusions at three different periods. Methods Landmarks previously identified on upper and lower dental casts were digitized on a three-dimensional digitizer MicroScribe-3DX and stored in Excel worksheets in order to assess the width, length and depth of patient's dental arches. Results During orthodontic preparation, the maxillary and mandibular transverse dimensions measured at the premolar regions were increased and maintained throughout the follow-up period. Intercanine width was increased only in the upper arch during orthodontic preparation. Maxillary arch length was reduced during orthodontic finalization, only. Upper and lower arch depths were stable in the study periods. Differences between centroid and gingival changes suggested that upper and lower arch premolars buccaly proclined during the pre-surgical period. Conclusions Maxillary and mandibular dental arches presented transverse expansion at premolar regions during preoperative orthodontic preparation, with a tendency towards buccal tipping. The transverse dimensions were not altered after surgery. No sagittal or vertical changes were observed during the follow-up periods. PMID:25279524

Three-dimensional dental arch changes of patients submitted to orthodontic-surgical treatment for correction of Class II malocclusion.

PubMed

Peixoto, Adriano Porto; dos Santos Pinto, Ary; Garib, Daniela Gamba; Gonçalves, João Roberto

2014-01-01

This study assessed the three-dimensional changes in the dental arch of patients submitted to orthodontic-surgical treatment for correction of Class II malocclusions at three different periods. Landmarks previously identified on upper and lower dental casts were digitized on a three-dimensional digitizer MicroScribe-3DX and stored in Excel worksheets in order to assess the width, length and depth of patient's dental arches. During orthodontic preparation, the maxillary and mandibular transverse dimensions measured at the premolar regions were increased and maintained throughout the follow-up period. Intercanine width was increased only in the upper arch during orthodontic preparation. Maxillary arch length was reduced during orthodontic finalization, only. Upper and lower arch depths were stable in the study periods. Differences between changes in centroid and gingival points suggested that upper and lower premolars buccaly proclined during the pre-surgical period. Maxillary and mandibular dental arches presented transverse expansion at premolar regions during preoperative orthodontic preparation, with a tendency towards buccal tipping. The transverse dimensions were not altered after surgery. No sagittal or vertical changes were observed during the follow-up periods.

The digital computer as a metaphor for the perfect laboratory experiment: Loophole-free Bell experiments

NASA Astrophysics Data System (ADS)

De Raedt, Hans; Michielsen, Kristel; Hess, Karl

2016-12-01

Using Einstein-Podolsky-Rosen-Bohm experiments as an example, we demonstrate that the combination of a digital computer and algorithms, as a metaphor for a perfect laboratory experiment, provides solutions to problems of the foundations of physics. Employing discrete-event simulation, we present a counterexample to John Bell's remarkable "proof" that any theory of physics, which is both Einstein-local and "realistic" (counterfactually definite), results in a strong upper bound to the correlations that are being measured in Einstein-Podolsky-Rosen-Bohm experiments. Our counterexample, which is free of the so-called detection-, coincidence-, memory-, and contextuality loophole, violates this upper bound and fully agrees with the predictions of quantum theory for Einstein-Podolsky-Rosen-Bohm experiments.

Linearity Analysis and Efficiency Testing of The Chromospheric Lyman-Alpha Spectro-Polarimeter (CLASP) Science Cameras for Flight

NASA Astrophysics Data System (ADS)

Walker, S. C.; Rachmeler, L.; Winebarger, A. R.; Champey, P. R.; Bethge, C.

2017-12-01

To unveil the complexity of the solar atmosphere, measurement of the magnetic field in the upper chromosphere and transition region is fundamentally important, as this is where the forces transition from plasma to magnetic field dominated. Measurements of the field are also needed to shed light on the energy transport from the lower atmospheric regions to the corona beyond. Such an advance in heliospheric knowledge became possible with the first flight of the international solar sounding rocket mission, CLASP. For the first time, linear polarization was measured in H Lyman-Alpha at 121.60 nm in September 2015. For linear polarization measurements in this line, high sensitivity is required due to the relatively weak polarization signal compared to the intensity. To achieve this high sensitivity, a low-noise sensor is required with good knowledge of its characterization, including linearity. This work presents further refinement of the linearity characterization of the cameras flown in 2015. We compared the current from a photodiode in the light path to the digital response of the detectors. Pre-flight CCD linearity measurements were taken for all three flight cameras and calculations of the linear fits and residuals were performed. However, the previous calculations included a smearing pattern and a digital saturation region on the detectors which were not properly taken into account. The calculations have been adjusted and were repeated for manually chosen sub-regions on the detectors that were found not to be affected. We present a brief overview of the instrument, the calibration data and procedures, and a comparison of the old and new linearity results. The CLASP cameras will be reused for the successor mission, CLASP2, which will measure the Mg II h & k lines between 279.45 nm and 280.35 nm. The new approach will help to better prepare for and to improve the camera characterization for CLASP2.

Linearity Analysis and Efficiency Testing of The Chromospheric Lyman-Alpha Spectro-Polarimeter (CLASP) Science Cameras for Flight

NASA Technical Reports Server (NTRS)

Walker, Salma C.; Rachmeler, Laurel; Winebarger, Amy; Champey, Patrick; Bethge, Christian

2017-01-01

To unveil the complexity of the solar atmosphere, measurement of the magnetic field in the upper chromosphere and transition region is fundamentally important, as this is where the forces transition from plasma to magnetic field dominated. Measurements of the field are also needed to elucidate the energy transport from the lower atmospheric regions to the corona beyond. Such an advance in heliospheric knowledge became possible with the first flight of the international solar sounding rocket mission, CLASP. For the first time, linear polarization was measured in Hydrogen Lyman-Alpha at 121.60 nm in September 2015. For linear polarization measurements in this emission line, high sensitivity is required due to the relatively weak polarization signal compared to the intensity. To achieve this high sensitivity, a low-noise sensor is required with good knowledge of its characterization, including linearity. This work presents further refinement of the linearity characterization of the cameras flown in 2015. We compared the current from a photodiode in the light path to the digital response of the detectors. Pre-flight CCD linearity measurements were taken for all three flight cameras and calculations of the linear fits and residuals were performed. However, the previous calculations included a smearing pattern and a digital saturation region on the detectors which were not properly taken into account. The calculations have been adjusted and were repeated for manually chosen sub-regions on the detectors that were found not to be affected. We present a brief overview of the instrument, the calibration data and procedures, and a comparison of the old and new linearity results. The CLASP cameras will be reused for the successor mission, CLASP2, which will measure the Magnesium II h & k emission lines between 279.45 nm and 280.35 nm. The new approach will help to better prepare for and to improve the camera characterization for CLASP2.

Linearity Analysis and Efficiency Testing of The Chromospheric Lyman-Alpha Spectro-Polarimeter (CLASP) Science Cameras for Flight

NASA Technical Reports Server (NTRS)

Walker, Salma C.; Rachmeler, Laurel; Winebarger, Amy; Champey, Patrick; Bethge, Christian

2018-01-01

To unveil the complexity of the solar atmosphere, measurement of the magnetic field in the upper chromosphere and transition region is fundamentally important, as this is where the forces transition from plasma to magnetic field dominated. Measurements of the field are also needed to elucidate the energy transport from the lower atmospheric regions to the corona beyond. Such an advance in heliospheric knowledge became possible with the first flight of the international solar sounding rocket mission, CLASP. For the first time, linear polarization was measured in Hydrogen Lyman-Alpha at 121.60 nm in September 2015. For linear polarization measurements in this emission line, high sensitivity is required due to the relatively weak polarization signal compared to the intensity. To achieve this high sensitivity, a low-noise sensor is required with good knowledge of its characterization, including linearity. This work presents further refinement of the linearity characterization of the cameras flown in 2015. We compared the current from a photodiode in the light path to the digital response of the detectors. Pre-flight CCD linearity measurements were taken for all three flight cameras and calculations of the linear fits and residuals were performed. However, the previous calculations included a smearing pattern and a digital saturation region on the detectors which were not properly taken into account. The calculations have been adjusted and were repeated for manually chosen sub-regions on the detectors that were found not to be affected. We present a brief overview of the instrument, the calibration data and procedures, and a comparison of the old and new linearity results. The CLASP cameras will be reused for the successor mission, CLASP2, which will measure the Magnesium II h & k emission lines between 279.45 nm and 280.35 nm. The new approach will help to better prepare for and to improve the camera characterization for CLASP2.

Pluto's Ultraviolet Airglow and Detection of Ions in the Upper Atmosphere

NASA Astrophysics Data System (ADS)

Steffl, A.; Young, L. A.; Kammer, J.; Gladstone, R.; Hinson, D. P.; Summers, M. E.; Strobel, D. F.; Stern, S. A.; Weaver, H. A., Jr.; Olkin, C.; Ennico Smith, K.

2017-12-01

In July 2015, the Alice ultraviolet spectrograph aboard the New Horizons spacecraft made numerous observations of Pluto and its atmosphere. We present here the far ultraviolet reflectance spectrum of Pluto and airglow emissions from its atmosphere. At wavelengths greater than 1400Å, Pluto's spectrum is dominated by sunlight reflected from the surface of the planet. Various hydrocarbon species such as C2H4 are detected in absorption of the solar continuum. Below 1400Å, Pluto's atmosphere is opaque and the surface cannot be detected. However, after carefully removing various sources of background light, we see extremely faint airglow emissions (<0.05 Rayleighs/Ångstrom) from Pluto's atmosphere. All of the emissions are produced by nitrogen in various forms: molecular, atomic, and singly ionized. The detection of N+ at 1086Å is the first, and thus far only, direct detection of ions in Pluto's atmosphere. This N+ emission line is produced primarily by dissociative photoionization of molecular N2 by solar EUV photons (energy > 34.7 eV; wavelength < 360Å). Notably absent from Pluto's spectrum are emission lines from argon at 1048 and 1067Å. We place upper limits on the amount of argon in Pluto's atmosphere above the tau=1 level (observed to be at 750km tangent altitude) that are significantly lower than pre-encounter atmospheric models.

XUV-exposed, non-hydrostatic hydrogen-rich upper atmospheres of terrestrial planets. Part I: atmospheric expansion and thermal escape.

PubMed

Erkaev, Nikolai V; Lammer, Helmut; Odert, Petra; Kulikov, Yuri N; Kislyakova, Kristina G; Khodachenko, Maxim L; Güdel, Manuel; Hanslmeier, Arnold; Biernat, Helfried

2013-11-01

The recently discovered low-density "super-Earths" Kepler-11b, Kepler-11f, Kepler-11d, Kepler-11e, and planets such as GJ 1214b represent the most likely known planets that are surrounded by dense H/He envelopes or contain deep H₂O oceans also surrounded by dense hydrogen envelopes. Although these super-Earths are orbiting relatively close to their host stars, they have not lost their captured nebula-based hydrogen-rich or degassed volatile-rich steam protoatmospheres. Thus, it is interesting to estimate the maximum possible amount of atmospheric hydrogen loss from a terrestrial planet orbiting within the habitable zone of late main sequence host stars. For studying the thermosphere structure and escape, we apply a 1-D hydrodynamic upper atmosphere model that solves the equations of mass, momentum, and energy conservation for a planet with the mass and size of Earth and for a super-Earth with a size of 2 R(Earth) and a mass of 10 M(Earth). We calculate volume heating rates by the stellar soft X-ray and extreme ultraviolet radiation (XUV) and expansion of the upper atmosphere, its temperature, density, and velocity structure and related thermal escape rates during the planet's lifetime. Moreover, we investigate under which conditions both planets enter the blow-off escape regime and may therefore experience loss rates that are close to the energy-limited escape. Finally, we discuss the results in the context of atmospheric evolution and implications for habitability of terrestrial planets in general.

Microwave boundary conditions on the atmosphere and clouds of Venus

NASA Technical Reports Server (NTRS)

Rossow, W. B.; Sagan, C.

1975-01-01

The dielectric properties of H2O/H2SO4 mixtures are deduced from the Debye equations and, for a well-mixed atmosphere, the structure of H2O and H2O/H2SO4 clouds is calculated. Various data on the planet together set an upper limit on the mixing ratio by number for H2O of about 0.001 in the lower Venus atmosphere, and for H2SO4 of about 0.00001. The polarization value of the real part of the refractive index of the clouds, the spectroscopic limits on the abundance of water vapor above the clouds, and the microwave data together set corresponding upper limits on H2O of approximately 0.0002 and on H2SO4 of approximately 0.000009. Upper limits on the surface density of total cloud constituents and of cloud liquid water are, respectively, about 0.1 g/sq cm and about 0.01 g/sq cm. The infrared opacities of 90 bars of CO2, together with the derived upper limits to the amounts of water vapor and liquid H2O/H2SO4, may be sufficient to explain the high surface temperatures through the greenhouse effect.

Mass motion in upper solar chromosphere detected from solar eclipse observation

NASA Astrophysics Data System (ADS)

Li, Zhi; Qu, Zhongquan; Yan, Xiaoli; Dun, Guangtao; Chang, Liang

2016-05-01

The eclipse-observed emission lines formed in the upper solar atmosphere can be used to diagnose the atmosphere dynamics which provides an insight to the energy balance of the outer atmosphere. In this paper, we analyze the spectra formed in the upper chromospheric region by a new instrument called Fiber Arrayed Solar Optic Telescope (FASOT) around the Gabon total solar eclipse on November 3, 2013. The double Gaussian fits of the observed profiles are adopted to show enhanced emission in line wings, while red-blue (RB) asymmetry analysis informs that the cool line (about 104 K) profiles can be decomposed into two components and the secondary component is revealed to have a relative velocity of about 16-45 km s^{-1}. The other profiles can be reproduced approximately with single Gaussian fits. From these fittings, it is found that the matter in the upper solar chromosphere is highly dynamic. The motion component along the line-of-sight has a pattern asymmetric about the local solar radius. Most materials undergo significant red shift motions while a little matter show blue shift. Despite the discrepancy of the motion in different lines, we find that the width and the Doppler shifts both are function of the wavelength. These results may help us to understand the complex mass cycle between chromosphere and corona.

Correction Technique for Raman Water Vapor Lidar Signal-Dependent Bias and Suitability for Water Wapor Trend Monitoring in the Upper Troposphere

NASA Technical Reports Server (NTRS)

Whiteman, D. N.; Cadirola, M.; Venable, D.; Calhoun, M.; Miloshevich, L; Vermeesch, K.; Twigg, L.; Dirisu, A.; Hurst, D.; Hall, E.;

A coupled ion-neutral photochemical model for the Titan atmosphere

NASA Astrophysics Data System (ADS)

Vuitton, V.; Yelle, R. V.; Klippenstein, S. J.; Horst, S. M.; Lavvas, P.

2013-12-01

Recent observations from the Cassini-Huygens spacecraft and the Herschel space observatory drastically increased our knowledge of Titan's chemical composition. The combination of data retrieved by Cassini INMS, UVIS, and CIRS allows deriving the vertical profiles of half a dozen species from 1000 to 100 km, while the HIFI instrument on Herschel reported on the first identification of HNC. Partial data or upper limits are available for almost 20 other CHON neutral species. The INMS and CAPS instruments onboard Cassini also revealed the existence of numerous positive and negative ions in Titan's upper atmosphere. We present the results of a 1D coupled ion-neutral photochemical model intended for the interpretation of the distribution of gaseous species in the Titan atmosphere. The model extends from the surface to the exobase. The atmospheric background, boundary conditions, vertical transport and aerosol opacity are all constrained by the Cassini-Huygens observations. The chemical network includes reactions between hydrocarbons, nitrogen and oxygen bearing species (including some species containing both nitrogen and oxygen, such as NO). It takes into account neutrals and both positive and negative ions with m/z extending up to about 100 u. Ab initio Transition State Theory calculations are performed in order to evaluate the rate coefficients and products for critical reactions. The production of minor nitrogen-bearing species and hydrocarbons is initiated by the dissociation and ionization of N2 and CH4 by solar VUV/EUV photons and associated photoelectrons in the upper atmosphere. We incorporate new high-resolution isotopic photoabsorption and photodissociation cross sections for N2 as well as new photodissociation branching ratios for CH4 and C2H2. The photodissociation of hydrocarbon radicals is taken into account and its impact on the chemistry is discussed for the first time. The presence of oxygen-bearing species is explained by an influx of oxygen originating from Enceladus in the upper atmosphere. The calculated vertical profiles of neutral and ion species generally agree with the existing observational data; some differences are highlighted. We discuss the chemical and physical processes responsible for the production and loss of some key species. We find that the production of neutral species in the upper atmosphere from electron-ion recombination reactions and neutral-neutral radiative association reactions is significant. In the stratosphere, the vertical profile of (cyano)polyynes is extremely sensitive to their heterogeneous loss on aerosols, a process that remains to be constrained experimentally and/or theoretically. This work was performed in the framework of the Marie Curie International Research Staff Exchange Scheme PIRSES-GA-2009-247509.

Heavy Ion Formation in Titan's Ionosphere: Magnetospheric Introduction of Free Oxygen and a Source of Titan's Aerosols?

NASA Technical Reports Server (NTRS)

Sittler, E. C., Jr.; Ali, A.; Cooper, J. F.; Hartle, R. E.; Johnson, R. E.; Coates, A. J.; Young, D. T.

2009-01-01

Discovery by Cassini's plasma instrument of heavy positive and negative ions within Titan's upper atmosphere and ionosphere has advanced our understanding of ion neutral chemistry within Titan's upper atmosphere, primarily composed of molecular nitrogen, with approx.2.5% methane. The external energy flux transforms Titan's upper atmosphere and ionosphere into a medium rich in complex hydrocarbons, nitriles and haze particles extending from the surface to 1200 km altitudes. The energy sources are solar UV, solar X-rays, Saturn's magnetospheric ions and electrons, solar wind and shocked magnetosheath ions and electrons, galactic cosmic rays (CCR) and the ablation of incident meteoritic dust from Enceladus' E-ring and interplanetary medium. Here it is proposed that the heavy atmospheric ions detected in situ by Cassini for heights >950 km, are the likely seed particles for aerosols detected by the Huygens probe for altitudes <100km. These seed particles may be in the form of polycyclic aromatic hydrocarbons (PAH) containing both carbon and hydrogen atoms CnHx. There could also be hollow shells of carbon atoms, such as C60, called fullerenes which contain no hydrogen. The fullerenes may compose a significant fraction of the seed particles with PAHs contributing the rest. As shown by Cassini, the upper atmosphere is bombarded by magnetospheric plasma composed of protons, H(2+) and water group ions. The latter provide keV oxygen, hydroxyl and water ions to Titan's upper atmosphere and can become trapped within the fullerene molecules and ions. Pickup keV N(2+), N(+) and CH(4+) can also be implanted inside of fullerenes. Attachment of oxygen ions to PAH molecules is uncertain, but following thermalization O(+) can interact with abundant CH4 contributing to the CO and CO2 observed in Titan's atmosphere. If an exogenic keV O(+) ion is implanted into the haze particles, it could become free oxygen within those aerosols that eventually fall onto Titan's surface. The process of freeing oxygen within aerosols could be driven by cosmic ray interactions with aerosols at all heights. This process could drive pre-biotic chemistry within the descending aerosols. Cosmic ray interactions with grains at the surface, including water frost depositing on grains from cryovolcanism, would further add to abundance of trapped free oxygen. Pre-biotic chemistry could arise within surface microcosms of the composite organic-ice grains, in part driven by free oxygen in the presence of organics and any heat sources, thereby raising the astrobiological potential for microscopic equivalents of Darwin's "warm ponds" on Titan.

Atmosphere, ocean, and land: Critical gaps in Earth system models

NASA Technical Reports Server (NTRS)

Prinn, Ronald G.; Hartley, Dana

1992-01-01

We briefly review current knowledge and pinpoint some of the major areas of uncertainty for the following fundamental processes: (1) convection, condensation nuclei, and cloud formation; (2) oceanic circulation and its coupling to the atmosphere and cryosphere; (3) land surface hydrology and hydrology-vegetation coupling; (4) biogeochemistry of greenhouse gases; and (5) upper atmospheric chemistry and circulation.

From COST 271 to 296 EU actions on ionospheric monitoring and modelling for terrestrial and Earth space radio systems

NASA Astrophysics Data System (ADS)

Zolesi, B.; Cander, Lj. R.; Altadill, D.

The ionospheric community has long been aware that co-operative research on an international basis is essential to deal with temporal and spatial changes in the ionosphere that influence the performance of terrestrial and Earth-space radio systems. The EU COST (Co-operation in the field of Scientific and Technical Research) 271 Action on "Effects of the Upper Atmosphere on Terrestrial and Earth-space Communications" has had during the period of October 2000-August 2004 the following main objectives: (1) to evaluate the influence of upper atmospheric conditions on terrestrial and Earth-space communications, (2) to develop methods and techniques to improve ionospheric models over Europe for telecommunication and navigation applications and (3) to transfer the results to the appropriate radiocommunication study groups of the International Telecommunication Union (ITU-R) and other national and international organizations dealing with the modern communication systems. At the beginning of 2005 the new 296 Action in the COST Telecommunications, Information Science and Technology domain on "Mitigation of Ionospheric Effects on Radio Systems (MIERS)" was approved for the period 2005-2009. The main objectives of the MIERS are: (a) to support and enhanced the existing European facilities for historical and real-time digital ionospheric data collection and exchange; (b) to develop an integrated approach to ionospheric modelling, create the mechanism needed to ingest processed data into models, extend and develop suitable mitigation models and define the protocols needed to link models together; and (c) to strengthen the areas of expertise that already exist by stimulating closer cooperation between scientists and users, focusing the scope of all the previous COST ionospheric related studies to the mitigation of ionospheric effects on radio systems. This paper summarises briefly how the major objectives of the COST271 Action have been achieved and what are the most important activities to be undertaken in the follow-on COST296 Action.

Complementarity of UV and IR differential absorption lidar for global measurements of atmospheric species

NASA Technical Reports Server (NTRS)

Megie, G.; Menzies, R. T.

1980-01-01

An analysis of the potential capabilities of a spectrally diversified DIAL technique for monitoring atmospheric species is presented assuming operation from an earth-orbiting platform. Emphasis is given to the measurement accuracies and spatial and temporal resolutions required to meet present atmospheric science objectives. The discussion points out advantages of spectral diversity to perform comprehensive studies of the atmosphere; in general it is shown that IR systems have an advantage in lower atmospheric measurements, while UV systems are superior for middle and upper atmospheric measurements.

Chemical Composition of the Atmosphere

NASA Astrophysics Data System (ADS)

Schlager, Hans; Grewe, Volker; Roiger, Anke

Atmospheric trace gases have an important impact on Earth's radiative budget, the oxidative or cleansing ability of the atmosphere, the formation, growth and properties of aerosols, air quality, and human health. During recent years, the coupling between atmospheric chemistry and climate has received particular attention. Therefore, research is now focused on the composition and processes in the upper troposphere and lower stratosphere, a key region in this respect. In this chapter the chemical composition of the atmosphere is addressed and selected examples of significant advances in this field are presented.

Geological and geothermal data use investigations for Application Explorer Mission-A (Heat Capacity Mapping Mission). [Yerington, Nevada mine area

NASA Technical Reports Server (NTRS)

Lyon, R. J. P.; Prelat, A. E. (Principal Investigator)

1980-01-01

Further digital processing of HCMM digital data was performed to extract the temperature from the day/night passes to calculate the apparent delta T in the Yerington, Nevada mine area. Further processing is needed to observe the atmospheric effect.

Cosmic Rays over the Upper Mid-West. Ph.D. Thesis

NASA Technical Reports Server (NTRS)

Rygg, T. A.

1972-01-01

Differential energy spectra of cosmic ray protons and helium nuclei in the 100 to 260 MeV/nucleon were measured on balloon flights in the upper midwestern (U.S.) area. Solar cycle variations of atmospheric secondary protons were also investigated.

Influence of the North Atlantic dipole on climate changes over Eurasia

NASA Astrophysics Data System (ADS)

Serykh, I. V.

2016-11-01

In this paper, some hydrophysical and meteorological characteristics of negative (1948-1976 and 1999-2015) and positive (1977-1998) phases of the Pacific Decadal Oscillation (PDO) and Interdecadal Pacific Oscillation (IPO) in the North Atlantic and Eurasia are constructed and investigated. Specifically, the near-surface temperature, sea-level atmospheric pressure, wind speed, heat content of the upper 700 m ocean layer, water temperature and salinity at various depths, the latent and sensible heat fluxes from the ocean to the atmosphere are analyzed. The fields obtained are in good agreement and complement each other. This gives important information about the hydrometeorological conditions in the region under study. Analysis of these data has shown that in the upper 1000 m North Atlantic layer there is a thermal dipole which can be interpreted as an oceanic analog of the atmospheric North Atlantic Oscillation (NAO). An index of the North Atlantic Dipole (NAD) as the difference between the mean heat contents in the upper 700 m oceanic layer between the regions (50°-70° N; 60°-10° W) and (20°-40° N; 80°-30° W) is proposed. A possible physical mechanism of the internal oscillations with a quasi-60-year period in the North Atlantics- Eurasia system of ocean-atmosphere interactions is discussed.

Design of Advanced Atmospheric Water Vapor Differential Absorption Lidar (DIAL) Detection System

NASA Technical Reports Server (NTRS)

Refaat, Tamer F.; Luck, William S., Jr.; DeYoung, Russell J.

1999-01-01

The measurement of atmospheric water vapor is very important for understanding the Earth's climate and water cycle. The lidar atmospheric sensing experiment (LASE) is an instrument designed and operated by the Langley Research Center for high precision water vapor measurements. The design details of a new water vapor lidar detection system that improves the measurement sensitivity of the LASE instrument by a factor of 10 are discussed. The new system consists of an advanced, very low noise, avalanche photodiode (APD) and a state-of-the-art signal processing circuit. The new low-power system is also compact and lightweight so that it would be suitable for space flight and unpiloted atmospheric vehicles (UAV) applications. The whole system is contained on one small printed circuit board (9 x 15 sq cm). The detection system is mounted at the focal plane of a lidar receiver telescope, and the digital output is read by a personal computer with a digital data acquisition card.

What Are Preadolescent Readers Doing Online? An Examination of Upper Elementary Students' Reading, Writing, and Communication in Digital Spaces

ERIC Educational Resources Information Center

Hutchison, Amy C.; Woodward, Lindsay; Colwell, Jamie

2016-01-01

The online reading, writing, and communication practices of students have been of significant interest to literacy researchers and teachers throughout the last several years, as insights into what students are currently doing in and outside of school can inform what they can be expected to know and be able to do in digital environments. Yet,…

Elevated atmospheric escape of atomic hydrogen from Mars induced by high-altitude water

NASA Astrophysics Data System (ADS)

Chaffin, M. S.; Deighan, J.; Schneider, N. M.; Stewart, A. I. F.

2017-01-01

Atmospheric loss has controlled the history of Martian habitability, removing most of the planet’s initial water through atomic hydrogen and oxygen escape from the upper atmosphere to space. In standard models, H and O escape in a stoichiometric 2:1 ratio because H reaches the upper atmosphere via long-lived molecular hydrogen, whose abundance is regulated by a photochemical feedback sensitive to atmospheric oxygen content. The relatively constant escape rates these models predict are inconsistent with known H escape variations of more than an order of magnitude on seasonal timescales, variation that requires escaping H to have a source other than H2. The best candidate source is high-altitude water, detected by the Mars Express spacecraft in seasonally variable concentrations. Here we use a one-dimensional time-dependent photochemical model to show that the introduction of high-altitude water can produce a large increase in the H escape rate on a timescale of weeks, quantitatively linking these observations. This H escape pathway produces prompt H loss that is not immediately balanced by O escape, influencing the oxidation state of the atmosphere for millions of years. Martian atmospheric water loss may be dominated by escape via this pathway, which may therefore potentially control the planet’s atmospheric chemistry. Our findings highlight the influence that seasonal atmospheric variability can have on planetary evolution.

Atmospheric science on the Galileo mission

NASA Technical Reports Server (NTRS)

Hunten, D. M.; Colin, L.; Hansen, J. E.

1986-01-01

The atmospheric science goals of the Galileo mission, and instruments of the probe and orbiter are described. The current data available, and the goals of the Galileo mission concerning the chemical composition of the Jovian atmosphere; the thermal structure of the atmosphere; the nature of cloud particles and cloud layering; the radiative energy balance; atmospheric dynamics; and the upper atmosphere are discussed. The objectives and operations of the atmospheric structure instrument, neutral mass spectrometer, helium abundance interferometer, nephelometer, net flux radiometer, lightning and radio emission detector, solid state imaging system, NIR mapping spectrometer, photopolarimeter radiometer, and UV spectrometer are examined.

Synoptic climatology of the long-distance dispersal of white pine blister rust I. Development of an upper level synoptic classification

Treesearch

K. L. Frank; L. S. Kalkstein; B. W. Geils; H. W. Thistle

2008-01-01

This study developed a methodology to temporally classify large scale, upper level atmospheric conditions over North America, utilizing a newly-developed upper level synoptic classification (ULSC). Four meteorological variables: geopotential height, specific humidity, and u- and v-wind components, at the 500 hPa level over North America were obtained from the NCEP/NCAR...

Mesoscale Waves in Jupiter Atmosphere

NASA Image and Video Library

1997-09-07

These two images of Jupiter atmosphere were taken with the violet filter of the Solid State Imaging CCD system aboard NASA Galileo spacecraft. Mesoscale waves can be seen in the center of the upper image. The images were obtained on June 26, 1996.

Optical Properties of atmospheric dust from twilight observations

NASA Technical Reports Server (NTRS)

Divari, N. B.; Zaginayilo, Y. I.; Kovalchuk, L. V.

1973-01-01

Three methods of approximation are described and used to separate the primary twilight brightness from the observed brightness. Photoelectric observations obtained are combined with observations from a balloon and from the observatory to derive the atmospheric scattering phase functions of 0.37 micron and 0.58 micron as a function of height. Comparison of these data with data for a Rayleigh atmosphere provide information on the optical properties of dust in the upper atmosphere.

3rd IAGA/ICMA Workshop on Vertical Coupling in the Atmosphere/Ionosphere System/ Abstract

DTIC Science & Technology

2007-01-10

energy and momentum from the lower atmosphere to the upper atmosphere and ionosphere and vice versa. The programme focussed on various aspects and...ICMA Workshop Vertical Coupling in the Atmosphere/Ionosphere System - 6 - The influence of global dependence of gravity wave energy in the troposphere...transport during the polar night of thermospheric odd nitrogen produced by lower- energy electron precipitation and solar extreme UV fluxes. However, at low

Science Enhancements by the MAVEN Participating Scientists

NASA Technical Reports Server (NTRS)

Grebowsky, J.; Fast, K.; Talaat, E.; Combi, M.; Crary, F.; England, S.; Ma, Y.; Mendillo, M.; Rosenblatt, P.; Seki, K.

2014-01-01

NASA implemented a Participating Scientist Program and released a solicitation for the Mars Atmosphere and Volatile EvolutioN mission (MAVEN) proposals on February 14, 2013. After a NASA peer review panel evaluated the proposals, NASA Headquarters selected nine on June 12, 2013. The program's intent is to enhance the science return from the mission by including new investigations that broaden and/or complement the baseline investigations, while still addressing key science goals. The selections cover a broad range of science investigations. Included are: a patching of a 3D exosphere model to an improved global ionosphere-thermosphere model to study the generation of the exosphere and calculate the escape rates; the addition of a focused study of upper atmosphere variability and waves; improvement of a multi-fluid magnetohydrodynamic model that will be adjusted according to MAVEN observations to enhance the understanding of the solar-wind plasma interaction; a global study of the state of the ionosphere; folding MAVEN measurements into the Mars International Reference Ionosphere under development; quantification of atmospheric loss by pick-up using ion cyclotron wave observations; the reconciliation of remote and in situ observations of the upper atmosphere; the application of precise orbit determination of the spacecraft to measure upper atmospheric density and in conjunction with other Mars missions improve the static gravity field model of Mars; and an integrated ion/neutral study of ionospheric flows and resultant heavy ion escape. Descriptions of each of these investigations are given showing how each adds to and fits seamlessly into MAVEN mission science design.

Science Enhancements by the MAVEN Participating Scientists

NASA Astrophysics Data System (ADS)

Grebowsky, J.; Fast, K.; Talaat, E.; Combi, M.; Crary, F.; England, S.; Ma, Y.; Mendillo, M.; Rosenblatt, P.; Seki, K.; Stevens, M.; Withers, P.

2015-12-01

NASA implemented a Participating Scientist Program and released a solicitation for the Mars Atmosphere and Volatile EvolutioN mission (MAVEN) proposals on February 14, 2013. After a NASA peer review panel evaluated the proposals, NASA Headquarters selected nine on June 12, 2013. The program's intent is to enhance the science return from the mission by including new investigations that broaden and/or complement the baseline investigations, while still addressing key science goals. The selections cover a broad range of science investigations. Included are: a patching of a 3D exosphere model to an improved global ionosphere-thermosphere model to study the generation of the exosphere and calculate the escape rates; the addition of a focused study of upper atmosphere variability and waves; improvement of a multi-fluid magnetohydrodynamic model that will be adjusted according to MAVEN observations to enhance the understanding of the solar-wind plasma interaction; a global study of the state of the ionosphere; folding MAVEN measurements into the Mars International Reference Ionosphere under development; quantification of atmospheric loss by pick-up using ion cyclotron wave observations; the reconciliation of remote and in situ observations of the upper atmosphere; the application of precise orbit determination of the spacecraft to measure upper atmospheric density and in conjunction with other Mars missions improve the static gravity field model of Mars; and an integrated ion/neutral study of ionospheric flows and resultant heavy ion escape. Descriptions of each of these investigations are given showing how each adds to and fits seamlessly into MAVEN mission science design.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Madaric, Juraj, E-mail: jurmad@hotmail.com; Klepanec, Andrej; Mistrik, Martin

Induction of therapeutic angiogenesis by autologous bone marrow mononuclear cell transplantation has been identified as a potential new option in patients with advanced lower-limb ischemia. There is little evidence of the benefit of intra-arterial cell application in upper-limb critical ischemia. We describe a patient with upper-extremity critical limb ischemia with digital gangrene resulting from hypothenar hammer syndrome successfully treated by intra-arterial autologous bone marrow mononuclear cell transplantation.

Trend-outflow method for understanding interactions of surface water with groundwater and atmospheric water for eight reaches of the Upper Rio Grande

NASA Astrophysics Data System (ADS)

Liu, Yi; Sheng, Zhuping

2011-11-01

SummaryAtmospheric water, surface water, and groundwater interact very actively through hydrologic processes such as precipitation, infiltration, seepage, irrigation, drainage, evaporation, and evapotranspiration in the Upper Rio Grande Basin. A trend-outflow method has been developed in this paper to gain a better understanding of the interactions based on cumulated inflow and outflow data for any river reaches of interest. A general trend-outflow equation was derived by associating the net interaction of surface water with atmospheric water as a polynomial of inflow and the net interaction of surface water with groundwater as a constant based on surface water budget. Linear and quadratic relations are probably two common trend-outflow types in the real world. It was found that trend-outflows of the Upper Rio Grande reaches, Española, Albuquerque, Socorro-Engle, Palomas, and Rincon are linear with inflow, while those of reaches, Belen, Mesilla and Hueco are quadratic. Reaches Belen, Mesilla and Hueco are found as water deficit reaches mainly for irrigated agriculture in extreme drought years.

Signature of Metallic ion in the upper atmosphere of Mars following the passage of comet C/2013 A1 (Siding Spring)

NASA Astrophysics Data System (ADS)

Benna, M.; Grebowsky, J. M.; Mahaffy, P. R.; Plane, J. M. C.; Yelle, R. V.; Jakosky, B. M.

2017-09-01

The Mars Atmosphere and Volatile EvolutioN (MAVEN) mission made the first in situ detection of metal ions in the upper atmosphere of Mars. These ions result from the ablation of dust particles from comet Siding Spring. This detection was carried out by the Neutral Gas and Ion Mass Spectrometer (NGIMS) on board the MAVEN spacecraft. Metal ions of Na, Mg, Al, K, Ti, Cr, Mn, Fe, Co, Ni, Cu, and Zn, and possibly of Si, and Ca, were identified in the ion spectra collected at altitudes of 185 km. The measurements revealed that Na ion was the most abundant species, and that the remaining metals were depleted with respect to the CI (type 1 carbonaceous Chondrites) abundance of Na ion.

Correlation of Upper-Atmospheric 7-Be with Solar Energetic Particle Events

NASA Technical Reports Server (NTRS)

Phillips, G. W.; Share, G. H.; King, S. E.; August, R. A.; Tylka, A. J.; Adams, J. H., Jr.; Panasyuk, M. I.; Nymmik, R. A.; Kuzhevskij, B. M.; Kulikauskas, V. S.;

A Massively Parallel Particle Code for Rarefied Ionized and Neutral Gas Flows in Earth and Planetary Atmospheres, Ionospheres and Magnetospheres

NASA Technical Reports Server (NTRS)

Combi, Michael R.

2004-01-01

In order to understand the global structure, dynamics, and physical and chemical processes occurring in the upper atmospheres, exospheres, and ionospheres of the Earth, the other planets, comets and planetary satellites and their interactions with their outer particles and fields environs, it is often necessary to address the fundamentally non-equilibrium aspects of the physical environment. These are regions where complex chemistry, energetics, and electromagnetic field influences are important. Traditional approaches are based largely on hydrodynamic or magnetohydrodynamic MHD) formulations and are very important and highly useful. However, these methods often have limitations in rarefied physical regimes where the molecular collision rates and ion gyrofrequencies are small and where interactions with ionospheres and upper neutral atmospheres are important.

Variations in the nerves of the thumb and index finger.

PubMed

Wallace, W A; Coupland, R E

1975-11-01

The digital nerves to the thumb and index finger have been studied by dissecting twenty-five embalmed upper limbs. The palmar digital nerves to the thumb were constant in position and course, with a short lateral cutaneous branch from the radial palmar digital nerve in 30 per cent of cases. The palmar digital nerves to the index finger had a variable pattern, the commonest arrangement, well described in Gray's Anatomy, occurring in 74 per cent of cases. The variations and their frequency are described. By examining histological cross-sections of the index finger it was found that of about 5,000 endoneurial tubes entering the finger, 60 per cent passed beyond the distal digital crease to supply the pulp and nail bed. The depth of the palmar digital nerves was about 3 millimetres, but less at the digital creases, and their diameter lay between 1 and 1.5 millimetres as far as the distal digital crease. Clinical applications of the findings are discussed.

Technology Needs Assessment of an Atmospheric Observation System for Multidisciplinary Air Quality/Meteorology Missions, Part 2

NASA Technical Reports Server (NTRS)

Alvarado, U. R.; Bortner, M. H.; Grenda, R. N.; Brehm, W. F.; Frippel, G. G.; Alyea, F.; Kraiman, H.; Folder, P.; Krowitz, L.

1982-01-01

The technology advancements that will be necessary to implement the atmospheric observation systems are considered. Upper and lower atmospheric air quality and meteorological parameters necessary to support the air quality investigations were included. The technology needs were found predominantly in areas related to sensors and measurements of air quality and meteorological measurements.

Defining the Space Atmosphere Interaction Region (SAIR)

NASA Astrophysics Data System (ADS)

Sojka, J. J.; David, M.; Schunk, R. W.

2016-12-01

Is there a unique region between space and a planet's atmosphere in which the majority of the interactions exist? Does the location of this region depend on the intensity of space weather events, i.e., solar flares or geomagnetic storms? Present day research has developed the term "Space Atmosphere Interactions Region" (SAIR) to express the idea that our understanding is least developed in regions of the upper atmosphere where incoming energy is transformed into some form of thermal energy of the local particle populations. During such processes, both the atmosphere and ionosphere are locally modified resulting in dynamics and modified chemistry that impacts a large part of the upper atmosphere and ionosphere. We consider energy sources from the lower atmosphere (waves), the Sun (flares), and magnetosphere (magnetic storms) and the locations of their energy transformation processes. From below, the atmospheric waves of different scales from gravity waves to planetary waves, while from above solar irradiance, auroral precipitation, and Joule heating are discussed as they determine the SAIR location. Of specific emphasis will be the dependence, or not, of the SAIR on the solar flare or geomagnetic storm intensity. This region will be identified as the location where local energy deposition equals or exceeds local thermal energy of the atmospheric constituents. This energy deposition impacts the atmosphere, ionosphere, and magnetosphere. Its impacts extend well beyond the SAIR. The relevance of the SAIR concept to other planets, and hence, exoplanet will be point out.

Radio scintillations observed during atmospheric occultations of Voyager: Internal gravity waves at Titan and magnetic field orientations at Jupiter and Saturn. Ph.D. Thesis

NASA Technical Reports Server (NTRS)

Hinson, D. P.

1983-01-01

The refractive index of planetary atmospheres at microwave frequencies is discussed. Physical models proposed for the refractive irregularities in the ionosphere and neutral atmosphere serve to characterize the atmospheric scattering structures, and are used subsequently to compute theoretical scintillation spectra for comparison with the Voyager occultation measurements. A technique for systematically analyzing and interpreting the signal fluctuations observed during planetary occultations is presented and applied to process the dual-wavelength data from the Voyager radio occultations by Jupiter, Saturn, and Titan. Results concerning the plasma irregularities in the upper ionospheres of Jupiter and Saturn are reported. The measured orientation of the irregularities is used to infer the magnetic field direction at several locations in the ionospheres of these two planets; the occultation measurements conflict with the predictions of Jovian magnetic field models, but generally confirm current models of Saturn's field. Wave parameters, including the vertical fluxes of energy and momentum, are estimated, and the source of the internal gravity waves discovered in Titan's upper atmosphere is considered.

STS-48 official crew insignia

NASA Image and Video Library

1999-08-27

STS048-S-001 (July 1991) --- Designed by the astronaut crew members, the patch represents the space shuttle orbiter Discovery in orbit about Earth after deploying the Upper Atmospheric Research Satellite (UARS) depicted in block letter style. The stars are those in the northern hemisphere as seen in the fall and winter when UARS will begin its study of Earth's atmosphere. The color bands on Earth's horizon, extending up to the UARS spacecraft, depict the study of Earth's atmosphere. The triangular shape represents the relationship among the three atmospheric processes that determine upper atmospheric structure and behavior: chemistry, dynamics and energy. In the words of the crew members, "This continuous process brings life to our planet and makes our planet unique in the solar system." The NASA insignia design for space shuttle flights is reserved for use by the astronauts and for other official use as the NASA Administrator may authorize. Public availability has been approved only in the form of illustrations by the various news media. When and if there is any change in this policy, which is not anticipated, it will be publicly announced. Photo credit: NASA

Magnetic tornadoes as energy channels into the solar corona.

PubMed

Wedemeyer-Böhm, Sven; Scullion, Eamon; Steiner, Oskar; van der Voort, Luc Rouppe; de la Cruz Rodriguez, Jaime; Fedun, Viktor; Erdélyi, Robert

2012-06-27

Heating the outer layers of the magnetically quiet solar atmosphere to more than one million kelvin and accelerating the solar wind requires an energy flux of approximately 100 to 300 watts per square metre, but how this energy is transferred and dissipated there is a puzzle and several alternative solutions have been proposed. Braiding and twisting of magnetic field structures, which is caused by the convective flows at the solar surface, was suggested as an efficient mechanism for atmospheric heating. Convectively driven vortex flows that harbour magnetic fields are observed to be abundant in the photosphere (the visible surface of the Sun). Recently, corresponding swirling motions have been discovered in the chromosphere, the atmospheric layer sandwiched between the photosphere and the corona. Here we report the imprints of these chromospheric swirls in the transition region and low corona, and identify them as observational signatures of rapidly rotating magnetic structures. These ubiquitous structures, which resemble super-tornadoes under solar conditions, reach from the convection zone into the upper solar atmosphere and provide an alternative mechanism for channelling energy from the lower into the upper solar atmosphere.

Monthly mean large-scale analyses of upper-tropospheric humidity and wind field divergence derived from three geostationary satellites

NASA Technical Reports Server (NTRS)

Schmetz, Johannes; Menzel, W. Paul; Velden, Christopher; Wu, Xiangqian; Vandeberg, Leo; Nieman, Steve; Hayden, Christopher; Holmlund, Kenneth; Geijo, Carlos

1995-01-01

This paper describes the results from a collaborative study between the European Space Operations Center, the European Organization for the Exploitation of Meteorological Satellites, the National Oceanic and Atmospheric Administration, and the Cooperative Institute for Meteorological Satellite Studies investigating the relationship between satellite-derived monthly mean fields of wind and humidity in the upper troposphere for March 1994. Three geostationary meteorological satellites GOES-7, Meteosat-3, and Meteosat-5 are used to cover an area from roughly 160 deg W to 50 deg E. The wind fields are derived from tracking features in successive images of upper-tropospheric water vapor (WV) as depicted in the 6.5-micron absorption band. The upper-tropospheric relative humidity (UTH) is inferred from measured water vapor radiances with a physical retrieval scheme based on radiative forward calculations. Quantitative information on large-scale circulation patterns in the upper-troposphere is possible with the dense spatial coverage of the WV wind vectors. The monthly mean wind field is used to estimate the large-scale divergence; values range between about-5 x 10(exp -6) and 5 x 10(exp 6)/s when averaged over a scale length of about 1000-2000 km. The spatial patterns of the UTH field and the divergence of the wind field closely resemble one another, suggesting that UTH patterns are principally determined by the large-scale circulation. Since the upper-tropospheric humidity absorbs upwelling radiation from lower-tropospheric levels and therefore contributes significantly to the atmospheric greenhouse effect, this work implies that studies on the climate relevance of water vapor should include three-dimensional modeling of the atmospheric dynamics. The fields of UTH and WV winds are useful parameters for a climate-monitoring system based on satellite data. The results from this 1-month analysis suggest the desirability of further GOES and Meteosat studies to characterize the changes in the upper-tropospheric moisture sources and sinks over the past decade.

URSI and Nachrichtentechnische Gesellschaft, General Session, Kleinheubach, West Germany, Oct. 6-10, 1986, Reports

NASA Astrophysics Data System (ADS)

Factors affecting the atmospheric propagation of EM waves, research on the ionosphere, and advances in radar and communications technology are examined in reviews and reports. Topics discussed include refraction corrections for radio astronomy and geodesy, speckle masking, radar studies of atmospheric motion, EISCAT measurements in the polar electrojet, active experiments in the polar ionosphere, and dispersion relations for drift-Alfven and drift-acoustic waves. Consideration is given to a microcomputer prediction system for HF communications over Europe, frequency determination of a hyperfine line of CH4 at 88 THz, multipath propagation in digital mobile communication, a robust digital voice transmission technique for land mobile radio, CMOS LSI for digital signal processing in mobile radio equipment, the representation of EM fields by dyadic Green functions, scalarization of Maxwell's equations for anisotropic media, and satellite antennas for land vehicles and aircraft.

Status of NASA aircraft engine emission reduction and upper atmosphere measurement programs

NASA Technical Reports Server (NTRS)

Rudey, R. A.; Lezberg, E. A.

1976-01-01

Advanced emission reduction techniques for five existing aircraft gas turbine engines are evaluated. Progress made toward meeting the 1979 EPA standards in rig tests of combustors for the five engines is reported. Results of fundamental combustion studies suggest the possibility of a new generation of jet engine combustor technology that would reduce oxides-of-nitrogen (NOx) emissions far below levels currently demonstrated in the engine-related programs. The Global Air Sampling Program (GAS) is now in full operation and is providing data on constituent measurements of ozone and other minor upper-atmosphere species related to aircraft emissions.

Upper Atmosphere Research Satellite (UARS) science data processing center implementation history

NASA Technical Reports Server (NTRS)

Herring, Ellen L.; Taylor, K. David

1990-01-01

NASA-Goddard is responsible for the development of a ground system for the Upper Atmosphere Research Satellite (UARS) observatory, whose launch is scheduled for 1991. This ground system encompasses a dedicated Central Data Handling Facility (CDHF); attention is presently given to the management of software systems design and implementation phases for CDHF by the UARS organization. Also noted are integration and testing activities performed following software deliveries to the CDHF. The UARS project has an obvious requirement for a powerful and flexible data base management system; an off-the-shelf commercial system has been incorporated.

Chemical and isotopic data collected from groundwater, surface-water, and atmospheric precipitation sites in Upper Kittitas County, Washington, 2010-12

USGS Publications Warehouse

Hinkle, Stephen R.; Ely, D. Matthew

2013-01-01

As part of a multidisciplinary U.S. Geological Survey study of water resources in Upper Kittitas County, Washington, chemical and isotopic data were collected from groundwater, surface-water, and atmospheric precipitation sites from 2010 to 2012. These data are documented here so that interested parties can quickly and easily find those chemical and isotopic data related to this study. The locations of the samples are shown on an interactive map of the study area. This report is dynamic; additional data will be added to it as they become available.

On remote sounding of the upper atmosphere of Venus

NASA Technical Reports Server (NTRS)

Houghton, J. T.; Taylor, F. W.

1975-01-01

Some of the possibilities for remote sensing of the upper atmosphere of Venus from an orbiting spacecraft are studied quantitatively. Temperature sounding over a wide vertical range, from the main cloud top near 60 km altitude to the nanobar level near 160 km, is shown to be feasible. Techniques which deconvolve the cloud structure from the temperature profile measurements are examined. Humidity measurements by simple radiometry are feasible for column abundances greater than or equal to 10 precipitable micrometers. The information content of limb radiance measurements, in different wavelengths and for various viewing geometries, is also analyzed.

Estimating net solar radiation using Landsat Thematic Mapper and digital elevation data

NASA Technical Reports Server (NTRS)

Dubayah, R.

1992-01-01

A radiative transfer algorithm is combined with digital elevation and satellite reflectance data to model spatial variability in net solar radiation at fine spatial resolution. The method is applied to the tall-grass prairie of the 16 x 16 sq km FIFE site (First ISLSCP Field Experiment) of the International Satellite Land Surface Climatology Project. Spectral reflectances as measured by the Landsat Thematic Mapper (TM) are corrected for atmospheric and topographic effects using field measurements and accurate 30-m digital elevation data in a detailed model of atmosphere-surface interaction. The spectral reflectances are then integrated to produce estimates of surface albedo in the range 0.3-3.0 microns. This map of albedo is used in an atmospheric and topographic radiative transfer model to produce a map of net solar radiation. A map of apparent net solar radiation is also derived using only the TM reflectance data, uncorrected for topography, and the average field-measured downwelling solar irradiance. Comparison with field measurements at 10 sites on the prairie shows that the topographically derived radiation map accurately captures the spatial variability in net solar radiation, but the apparent map does not.

DMSP Special Sensor Microwave/Imager Calibration/Validation. Volume 1

DTIC Science & Technology

1990-01-01

each channel samples the hot load on every scan and commands a gain change up when the hot load is below 7/16th of the analog to digital converter range...OLS imagery. A threshold blanking technique was used to convert the manual analyses into synthetic digital images containing the cloud truth...should include OLS digital thermal infrared into the analysis. While this will be of use only in clear, relatively dry atmospheric conditions, the

Coaxial digital holography measures particular matter in cloud and ambient atmosphere

NASA Astrophysics Data System (ADS)

Li, Baosheng; Yu, Haonan; Jia, Yizhen; Tao, Xiaojie; Zhang, Yang

2018-02-01

In the artificially affected weather, the detection of cloud droplets particles provides an important reference for the effective impact of artificial weather. Digital holography has the unique advantages of full-field, non-contact, no damage, real-time and quantification. In this paper, coaxial digital holography is used to record the polyethylene standard particles and aluminum scrap, and some important parameters, such as three-dimensional coordinate spatial distribution and particle size, will be obtained by the means of analyzing the digital hologram of the particle. The experimental results verify the feasibility of the coaxial digital holographic device applied to the measurement of the cloud parameters, and complete the construction of the coaxial digital holographic system and the measurement of the particles.

The UARS and EOS Microwave Limb Sounder (MLS) Experiments.

NASA Astrophysics Data System (ADS)

Waters, J. W.; Read, W. G.; Froidevaux, L.; Jarnot, R. F.; Cofield, R. E.; Flower, D. A.; Lau, G. K.; Pickett, H. M.; Santee, M. L.; Wu, D. L.; Boyles, M. A.; Burke, J. R.; Lay, R. R.; Loo, M. S.; Livesey, N. J.; Lungu, T. A.; Manney, G. L.; Nakamura, L. L.;  Perun, V. S.;  Ridenoure, B. P.;  Shippony, Z.;  Siegel, P. H.;  Thurstans, R. P.;  Harwood, R. S.;  Pumphrey, H. C.;  Filipiak, M. J.

1999-01-01

The Microwave Limb Sounder (MLS) experiments obtain measurements of atmospheric composition, temperature, and pressure by observations of millimeter- and submillimeter-wavelength thermal emission as the instrument field of view is scanned through the atmospheric limb. Features of the measurement technique include the ability to measure many atmospheric gases as well as temperature and pressure, to obtain measurements even in the presence of dense aerosol and cirrus, and to provide near-global coverage on a daily basis at all times of day and night from an orbiting platform. The composition measurements are relatively insensitive to uncertainties in atmospheric temperature. An accurate spectroscopic database is available, and the instrument calibration is also very accurate and stable. The first MLS experiment in space, launched on the (NASA) Upper Atmosphere Research Satellite (UARS) in September 1991, was designed primarily to measure stratospheric profiles of ClO, O3, H2O, and atmospheric pressure as a vertical reference. Global measurement of ClO, the predominant radical in chlorine destruction of ozone, was an especially important objective of UARS MLS. All objectives of UARS MLS have been accomplished and additional geophysical products beyond those for which the experiment was designed have been obtained, including measurement of upper-tropospheric water vapor, which is important for climate change studies. A follow-on MLS experiment is being developed for NASA's Earth Observing System (EOS) and is scheduled to be launched on the EOS CHEMISTRY platform in late 2002. EOS MLS is designed for many stratospheric measurements, including HOx radicals, which could not be measured by UARS because adequate technology was not available, and better and more extensive upper-tropospheric and lower-stratospheric measurements.

New Horizons Upper Limits on O{sub 2} in Pluto’s Present Day Atmosphere

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kammer, J. A.; Gladstone, G. R.; Stern, S. A.

The surprising discovery by the Rosetta spacecraft of molecular oxygen (O{sub 2}) in the coma of comet 67P/Churyumov–Gerasimenko challenged our understanding of the inventory of this volatile species on and inside bodies from the Kuiper Belt. That discovery motivated our search for oxygen in the atmosphere of Kuiper Belt planet Pluto, because O{sub 2} is volatile even at Pluto’s surface temperatures. During the New Horizons flyby of Pluto in 2015 July, the spacecraft probed the composition of Pluto’s atmosphere using a variety of observations, including an ultraviolet solar occultation observed by the Alice UV spectrograph. As described in these reports, absorptionmore » by molecular species in Pluto’s atmosphere yielded detections of N{sub 2}, as well as hydrocarbon species such as CH{sub 4}, C{sub 2}H{sub 2}, C{sub 2}H{sub 4}, and C{sub 2}H{sub 6}. Our work here further examines this data to search for UV absorption from molecular oxygen (O{sub 2}), which has a significant cross-section in the Alice spectrograph bandpass. We find no evidence for O{sub 2} absorption and place an upper limit on the total amount of O{sub 2} in Pluto’s atmosphere as a function of tangent height up to 700 km. In most of the atmosphere, this upper limit in line-of-sight abundance units is ∼3 × 10{sup 15} cm{sup −2}, which, depending on tangent height, corresponds to a mixing ratio of 10{sup −6} to 10{sup −4}, far lower than in comet 67P/CG.« less

Wide-Field Ultraviolet Spectrometer for Planetary Exospheres and Thermospheres

NASA Astrophysics Data System (ADS)

Fillingim, M. O.; Wishnow, E. H.; Miller, T.; Edelstein, J.; Lillis, R. J.; Korpela, E.; England, S.; Shourt, W. V.; Siegmund, O.; McPhate, J.; Courtade, S.; Curtis, D. W.; Deighan, J.; Chaffin, M.; Harmoul, A.; Almatroushi, H. R.

2016-12-01

Understanding the composition, structure, and variability of a planet's upper atmosphere - the exosphere and thermosphere - is essential for understanding how the upper atmosphere is coupled to the lower atmosphere, magnetosphere and near-space environment, and the Sun. Ultraviolet spectroscopy can directly observe emissions from constituents in the exosphere and thermosphere. From such observations, the structure, composition, and variability can be determined.We will present the preliminary design for a wide field ultraviolet imaging spectrometer for remote sensing of planetary atmospheres. The imaging spectrometer achieves an extremely large instantaneous 110 degree field of view with no moving scanning mirror. The imaging resolution is very appropriate for extended atmospheric emission studies, with a resolution of better than 0.3 degrees at the center to 0.4 degrees at the edges of the field. The spectral range covers 120 - 170 nm, encompassing emissions from H, O, C, N, CO, and N2, with an average spectral resolution of 1.5 nm. The instrument is composed of a 2-element wide-field telescope, a 3-element Offner spectrometer, and a sealed MCP detector system contained within a compact volume of about 40 x 25 x 20 cm. We will present the optical and mechanical design as well as the predicted optical performance.The wide instantaneous FOV simplifies instrument and spacecraft operations by removing the need for multiple scans (either from a scan mirror or spacecraft slews) to cover the regions of interest. This instrumentation can allow for two-dimensional spectral information to be built up with simple spacecraft operation or just using spacecraft motion. Applications to the terrestrial geocorona and thermosphere will be addressed as well as applications to the upper atmospheres of other planetary objects.

XUV-Exposed, Non-Hydrostatic Hydrogen-Rich Upper Atmospheres of Terrestrial Planets. Part I: Atmospheric Expansion and Thermal Escape

PubMed Central

Lammer, Helmut; Odert, Petra; Kulikov, Yuri N.; Kislyakova, Kristina G.; Khodachenko, Maxim L.; Güdel, Manuel; Hanslmeier, Arnold; Biernat, Helfried

2013-01-01

Abstract The recently discovered low-density “super-Earths” Kepler-11b, Kepler-11f, Kepler-11d, Kepler-11e, and planets such as GJ 1214b represent the most likely known planets that are surrounded by dense H/He envelopes or contain deep H2O oceans also surrounded by dense hydrogen envelopes. Although these super-Earths are orbiting relatively close to their host stars, they have not lost their captured nebula-based hydrogen-rich or degassed volatile-rich steam protoatmospheres. Thus, it is interesting to estimate the maximum possible amount of atmospheric hydrogen loss from a terrestrial planet orbiting within the habitable zone of late main sequence host stars. For studying the thermosphere structure and escape, we apply a 1-D hydrodynamic upper atmosphere model that solves the equations of mass, momentum, and energy conservation for a planet with the mass and size of Earth and for a super-Earth with a size of 2 REarth and a mass of 10 MEarth. We calculate volume heating rates by the stellar soft X-ray and extreme ultraviolet radiation (XUV) and expansion of the upper atmosphere, its temperature, density, and velocity structure and related thermal escape rates during the planet's lifetime. Moreover, we investigate under which conditions both planets enter the blow-off escape regime and may therefore experience loss rates that are close to the energy-limited escape. Finally, we discuss the results in the context of atmospheric evolution and implications for habitability of terrestrial planets in general. Key Words: Stellar activity—Low-mass stars—Early atmospheres—Earth-like exoplanets—Energetic neutral atoms—Ion escape—Habitability. Astrobiology 13, 1011–1029. PMID:24251443

First middle-atmospheric zonal wind profile measurements with a new ground-based microwave Doppler-spectro-radiometer

NASA Astrophysics Data System (ADS)

Rüfenacht, R.; Kämpfer, N.; Murk, A.

2012-12-01

Today, the wind data for the upper stratosphere and lower mesosphere are commonly extrapolated using models or calculated from measurements of the temperature field, but are not measured directly. Still, such measurements would allow direct observations of dynamic processes and thus provide a better understanding of the circulation in this altitude region where the zonal wind speed reaches a maximum. Observations of middle-atmospheric winds are also expected to provide deeper insight in the coupling between the upper and the lower atmosphere, especially in the case of sudden stratospheric warming events. Furthermore, as the local chemical composition of the middle atmosphere can be measured with high accuracy, wind data could be beneficial for the interpretation of the associated transport processes. In future, middle-atmospheric wind measurements could help to improve atmospheric circulation models. Aiming to contribute to the closing of this data gap the Institute of Applied Physics of the University of Bern built a new ground-based 142 GHz Doppler-spectro-radiometer with the acronym WIRA (WInd RAdiometer) specifically designed for the measurement of middle-atmospheric wind. Currently wind speeds in five levels between 30 and 79 km can be retrieved what makes WIRA the first instrument continuously measuring profiles of horizontal wind in this altitude range. On the altitude levels where our measurement can be compared to ECMWF very good agreement has been found in the long-term statistics, with WIRA = (0.98±0.02) × ECMWF + (0.44±0.91) m/s on average, as well as in short time structures with a duration of a few days. WIRA uses a passive double sideband heterodyne receiver together with a digital Fourier transform spectrometer for the data acquisition. A big advantage of the radiometric approach is that such instruments can also operate under adverse weather conditions and thus provide a continuous time series for the given location. The optics enables the instrument to scan a wide range of azimuth angles including the directions east, west, north, and south for zonal and meridional wind measurements. The design of the radiometer is fairly compact and its calibration does not rely on liquid nitrogen what makes it transportable and suitable for campaign use. WIRA is conceived in a way that it can be operated remotely and does hardly require any maintenance. A first time series of 11 months of zonal wind data was obtained for Bern (46°57' N, 7°26' E) before the instrument was moved to Sodankylä (67°22' N, 26°38' E) in September 2011 to measure at polar latitudes during a period of 10 months. After a technical upgrade (integration of a pre-amplifier and a sideband filter) aiming to increase the instruments sensitivity a new measurement campaign at the site of the Observatoire de Haute-Provence for data intercomparison with the NDACC Rayleigh-Mie Doppler wind lidar is planned during the winter 2011/2012. At the conference, the main results from these campaigns will be presented along with the measurement technique and the instrument properties.

First middle-atmospheric zonal wind profile measurements with a new ground-based microwave Doppler-spectro-radiometer

NASA Astrophysics Data System (ADS)

Rüfenacht, Rolf; Kämpfer, Niklaus; Murk, Axel

2013-04-01

Today, the wind data for the upper stratosphere and lower mesosphere are commonly extrapolated using models or calculated from measurements of the temperature field, but are not measured directly. Still, such measurements would allow direct observations of dynamic processes and thus provide a better understanding of the circulation in this altitude region where the zonal wind speed reaches a maximum. Observations of middle-atmospheric winds are also expected to provide deeper insight in the coupling between the upper and the lower atmosphere, especially in the case of sudden stratospheric warming events. Furthermore, as the local chemical composition of the middle atmosphere can be measured with high accuracy, wind data could be beneficial for the interpretation of the associated transport processes. In future, middle-atmospheric wind measurements could help to improve atmospheric circulation models. Aiming to contribute to the closing of this data gap the Institute of Applied Physics of the University of Bern built a new ground-based 142 GHz Doppler-spectro-radiometer with the acronym WIRA (WInd RAdiometer) specifically designed for the measurement of middle-atmospheric wind. Until now wind speeds in five levels between 30 and 79 km can be retrieved what made WIRA the first instrument continuously measuring profiles of horizontal wind in this altitude range. On the altitude levels where our measurement can be compared to ECMWF very good agreement has been found in the long-term statistics, with WIRA = (0.98±0.02) × ECMWF + (0.44±0.91) m/s on average, as well as in short time structures with a duration of a few days. WIRA uses a passive heterodyne receiver together with a digital Fourier transform spectrometer for the data acquisition. A big advantage of the radiometric approach is that such instruments can also operate under adverse weather conditions and thus provide a continuous time series for the given location. The optics enables the instrument to scan a wide range of azimuth angles including the directions east, west, north, and south for zonal and meridional wind measurements. The design of the radiometer is fairly compact and its calibration does not rely on liquid nitrogen what makes it transportable and suitable for campaign use. WIRA is conceived in a way that it can be operated remotely and does hardly require any maintenance. A first time series of 11 months of zonal wind data was obtained for Bern (46° 57' N, 7° 26' E) before the instrument was moved to Sodankylä (67° 22' N, 26° 38' E) in September 2011 to measure at polar latitudes during a period of 10 months. After a substantial technical upgrade (integration of a pre-amplifier and sideband filter) increasing the instruments signal to noise ratio by a factor of 2.4 the measurement campaign of the ARISE project at the site of the Observatoire de Haute-Provence was joined where among others data intercomparison with a newly operational Rayleigh-Mie Doppler wind lidar is planned. At the conference, the main results from these campaigns will be presented along with the measurement technique and the instrument properties.

Proceedings of the Twelfth NASA Propagation Experimenters Meeting (NAPEX 12)

NASA Technical Reports Server (NTRS)

Davarian, Faramaz (Editor)

1988-01-01

The NASA Propagation Experimenters Meeting was convened on June 9 and 10, 1988. Pilot Field Experiments propagation studies, mobile communication systems, signal fading, communication satellites rain gauge network measurements, atmospheric attenuation studies, optical communication through the atmosphere, and digital beacon receivers were among the topics discussed.

The EISCAT_3D Project in Norway: E3DN

NASA Astrophysics Data System (ADS)

La Hoz, C.; Oksavik, K.

2013-12-01

EISCAT_3D (E3D) is a project to build the next generation of incoherent scatter radars endowed with 3-dimensional scalar and vector capabilities that will replace the current EISCAT radars in Northern Scandinavia. One active (transmitting) site in Norway and four passive (receiving) sites in the Nordic countries will provide 3-D vector imaging capabilities by rapid scanning and multi-beam forming. The unprecedented flexibility of the solid-state transmitter with high duty-cycle, arbitrary wave-forming and polarisation and its pulsed power of 10 MW will provide unrivalled experimental capabilities to investigate the highly non-stationary and non-homogeneous state of the polar upper atmosphere. Aperture Synthesis Imaging Radar (ASIR) will to endow E3D with imaging capabilities in 3-dimensions that includes sub-beam resolution. Complemented by pulse compression, it will provide 3-dimensional images of certain types of incoherent scatter radar targets resolved to about 100 metres at 100 km range, depending on the signal-to-noise ratio. The Norwegian scientific programme is inspired by the pioneer polar scientist Kristian Birkeland (picture) and includes pressing questions on polar upper atmospheric research, among others: (Q1) How to proceed beyond the present simplistic, static, stationary and homogeneous analysis of upper atmospheric and ionospheric processes? (Q2) How does space weather affect ionospheric processes and how to support modelling and space weather services? (Q3) How to advance fundamental plasma physics by employing the ionosphere as a natural plasma physics laboratory? (Q4) How does the influx of extraterrestrial material interact with the upper atmosphere and where does the material originate from? (Q5) How does solar activity couple from geospace into the lower atmosphere and climate system, and does this energy change the wave forcing of geospace from below? Kristian Birkeland, Norwegian scientist and pioneer in polar and auroral research.

Nitric oxide in the upper stratosphere - Measurements and geophysical interpretation

NASA Technical Reports Server (NTRS)

Harvath, J. J.; Frederick, J. E.; Orsini, N.; Douglass, A. R.

1983-01-01

A rocket-borne parachute-deployed chemiluminescence instrument has obtained seven new measurements of atmospheric nitric oxide for altitudes between 30 and 50 km at mid-latitudes. These results, when combined with profiles measured by an earlier version of the instrument, cover all four seasons and provide a more comprehensive picture of upper stratospheric nitric oxide than has been available previously. At the highest altitudes studied, the vertical gradient in mixing ratio displays positive and negative values during different observations, with the largest values tending to appear at the greatest heights in summer. Examination of the differences among the profiles, which exceed a factor of 3 near the stratopause, suggests that they arise from the action of transport processes which carry air into the mid-latitude upper stratosphere from regions of the atmosphere that contain widely different odd-nitrogen abundances.

Scientific program in planetary atmospheric studies

NASA Technical Reports Server (NTRS)

Broadfoot, A. L.

1983-01-01

The Voyager encounters with Jupiter led to two main areas of investigation: (1) the definition of the structure and composition of the upper atmosphere and the interaction of the magnetosphere and atmosphere, and (2) the study of the plasma torus using the EUV (Extreme Ultraviolet) data in conjunction with ground-based and in-situ measurements. In the course of these investigations, the atmosphere studies were extended to a comparative study with the bound atmospheres of Saturn and Titan; and the torus study expanded to include the extended atmospheres of Titan (the H torus) and the rings of Saturn.

The atmospheric abundance of SO2 on Io

NASA Technical Reports Server (NTRS)

Ballester, Gilda E.; Strobel, Darrell F.; Moos, H. Warren; Feldman, Paul D.

1990-01-01

The IUE satellite has obtained near-UV spectra of Io with sufficient resolution to ascertain the east, or leading and west, or trailing hemispheres' dayside atmosphere SO2 abundance. The derived geometric albedos are compared with various model albedos that might result from proposed SO2 atmospheres, as well as from localized, sublimation- or volcanism-generated atmospheres. A homogeneous-layer alternative atmosphere is introduced whose upper limit on the average SO2 column density for both hemispheres implies that a collisionally thick SO2 atmosphere of intermediate density may have been present on Io's dayside during the present observations.

Satellite to measure equatorial ozone layer

NASA Technical Reports Server (NTRS)

1975-01-01

The Atmosphere Explorer E (Explorer 55) Satellite is described. The satellite will gather information on the earth's upper atmosphere, particularly regarding the condition of the protective ozone layer. The satellite will also provide information concerning the earth's heat balance, and heat flow characteristics, and energy conversion mechanisms.

Meteoric Material: An Important Component of Planetary Atmospheres

NASA Technical Reports Server (NTRS)

Grebowsky, Joseph M.; Moses, Julianne I.; Pesnell, W. Dean; Vondrak, Richard R. (Technical Monitor)

2001-01-01

Interplanetary dust particles (IDPs) interact with all planetary atmospheres and leave their imprint as perturbations of the background atmospheric chemistry and structure. They lead to layers of metal ions that can become the dominant positively charged species in lower ionospheric regions. Theoretical models and radio occultation measurements provide compelling evidence that such layers exist in all planetary atmospheres. In addition IDP ablation products can affect neutral atmospheric chemistry, particularly at the outer planets where the IDPs supply oxygen compounds like water and carbon dioxide to the upper atmospheres. Aerosol or smoke particles from incomplete ablation or recondensation of ablated IDP vapors may also have a significant impact on atmospheric properties.

Condition of the upper atmosphere of the Earth at the final stage of flight manned orbital facility (MOF) "Mir". The modeling description

NASA Astrophysics Data System (ADS)

Boyarchuk, K. A.; Ivanov-Kholodny, G. S.; Kolomiitsev, O. P.; Surotkin, V. A.

At flooding MOF ``Mir'' the information on forecasting a condition of the upper atmosphere was used. The forecast was carried out on the basis of numerical model of an atmosphere, which was developed in IZMIRAN. This model allows reproducing and predicting a situation in an Earth space, in an atmosphere and an ionosphere, along an orbit of flight of a space vehicle in the various periods of solar-geophysical conditions. Thus preliminary forecasting solar and geomagnetic activity was carried out on the basis of an individual technique. Before the beginning of operation on flooding MOF ``Mir'' it was found out, that solar activity began to accrue catastrophically. The account of the forecast of its development has forced to speed up the moment of flooding to avoid dangerous development of events. It has allowed minimizing a risk factor - ``Mir'' was flooded successful in the commanded area of Pacific Ocean.

Pluto's Solar Occultation from New Horizons

NASA Astrophysics Data System (ADS)

Young, Leslie; Kammer, Joshua; Steffl, Andrew J.; Gladstone, Randy; Summers, Michael; Strobel, Darrell F.; Hinson, David P.; Stern, S. Alan; Weaver, Harold A.; Olkin, Catherine; Ennico, Kimberly; McComas, Dave; New Horizons Atmospheres Science Theme Team

2017-10-01

The Alice instrument on NASA’s New Horizons spacecraft observed an ultraviolet solar occultation by Pluto's atmosphere on 2015 July 14. We derived line-of-sight abundances and local number densities for the major species (N2 and CH4) and minor hydrocarbons (C2H2, C2H4, C2H6), and line-of-sight optical depth and extinction coefficients for the haze. Our major conclusions are that (1) we confirmed temperatures in Pluto’s upper atmosphere that were colder than expected before the New Horizons flyby, with upper atmospheric temperatures near 65-68 K, and subsequently lower escape rates, (2) the lower atmosphere was very stable, placing the homopause within 12 km of the surface, (3) the abundance profiles of the “C2Hx hydrocarbons” had non-exponential density profiles that compare favorably with models for hydrocarbon production near 300-400 km and haze condensation near 200 km, and (4) haze had an extinction coefficient approximately proportional to N2 density.This work was supported by NASA’s New Horizons project.

Solar Wind Interaction with the Martian Upper Atmosphere at Early Mars/Extreme Solar Conditions

NASA Astrophysics Data System (ADS)

Dong, C.; Bougher, S. W.; Ma, Y.; Toth, G.; Lee, Y.; Nagy, A. F.; Tenishev, V.; Pawlowski, D. J.; Combi, M. R.

2014-12-01

The investigation of ion escape fluxes from Mars, resulting from the solar wind interaction with its upper atmosphere/ionosphere, is important due to its potential impact on the long-term evolution of Mars atmosphere (e.g., loss of water) over its history. In the present work, we adopt the 3-D Mars cold neutral atmosphere profiles (0 ~ 300 km) from the newly developed and validated Mars Global Ionosphere Thermosphere Model (M-GITM) and the 3-D hot oxygen profiles (100 km ~ 5 RM) from the exosphere Monte Carlo model Adaptive Mesh Particle Simulator (AMPS). We apply these 3-D model output fields into the 3-D BATS-R-US Mars multi-fluid MHD (MF-MHD) model (100 km ~ 20 RM) that can simulate the interplay between Mars upper atmosphere and solar wind by considering the dynamics of individual ion species. The multi-fluid MHD model solves separate continuity, momentum and energy equations for each ion species (H+, O+, O2+, CO2+). The M-GITM model together with the AMPS exosphere model take into account the effects of solar cycle and seasonal variations on both cold and hot neutral atmospheres. This feature allows us to investigate the corresponding effects on the Mars upper atmosphere ion escape by using a one-way coupling approach, i.e., both the M-GITM and AMPS model output fields are used as the input for the multi-fluid MHD model and the M-GITM is used as input into the AMPS exosphere model. In this study, we present M-GITM, AMPS, and MF-MHD calculations (1-way coupled) for 2.5 GYA conditions and/or extreme solar conditions for present day Mars (high solar wind velocities, high solar wind dynamic pressure, and high solar irradiance conditions, etc.). Present day extreme conditions may result in MF-MHD outputs that are similar to 2.5 GYA cases. The crustal field orientations are also considered in this study. By comparing estimates of past ion escape rates with the current ion loss rates to be returned by the MAVEN spacecraft (2013-2016), we can better constrain the total ion loss to space over Mars history, and thus enhance the science returned from the MAVEN mission.

Impacts of atmospheric variability on a coupled upper-ocean/ecosystem model of the subarctic Northeast Pacific

NASA Astrophysics Data System (ADS)

Monahan, Adam Hugh; Denman, Kenneth L.

2004-06-01

The biologically-mediated flux of carbon from the upper ocean to below the permanent thermocline (the biological pump) is estimated to be ˜10 PgC/yr [, 2001], and plays an important role in the global carbon cycle. A detailed quantitative understanding of the dynamics of the biological pump is therefore important, particularly in terms of its potential sensitivity to climate change and its role in this change via feedback processes. Previous studies of coupled upper-ocean/planktonic ecosystem dynamics have considered models forced by observed atmospheric variability or by smooth annual and diurnal cycles. The second approach has the drawback that environmental variability is ubiquitous in the climate system, and may have a nontrivial impact on the (nonlinear) dynamics of the system, while the first approach is limited by the fact that observed time series are generally too short to obtain statistically robust characterizations of variability in the system. In the present study, an empirical stochastic model of high-frequency atmospheric variability (with a decorrelation timescale of less than a week) is estimated from long-term observations at Ocean Station Papa in the northeast subarctic Pacific. This empirical model, the second-order statistics of which resemble those of the observations to a good approximation, is used to produce very long (1000-year) realizations of atmospheric variability which are used to drive a coupled upper-ocean/ecosystem model. It is found that fluctuations in atmospheric forcing do not have an essential qualitative impact on most aspects of the dynamics of the ecosystem when primary production is limited by the availability of iron, although pronounced interannual variability in diatom abundance is simulated (even in the absence of episodic iron fertilization). In contrast, the impacts of atmospheric variability are considerably more significant when phytoplankton growth is limited in the summer by nitrogen availability, as observed closer to the North American coast. Furthermore, the high-frequency variability in atmospheric forcing is associated with regions in parameter space in which the system alternates between iron and nitrogen limitation on interannual to interdecadal timescales. Both the mean and variability of export production are found to be significantly larger in the nitrogen-limited regime than in the iron-limited regime.

Drivers of methane uptake by montane forest soils in the Peruvian Andes

NASA Astrophysics Data System (ADS)

Jones, Sam; Diem, Torsten; Huaraca Quispe, Lidia; Cahuana, Adan; Meir, Patrick; Teh, Yit

2016-04-01

The exchange of methane between the soils of humid tropical forests and the atmosphere is relatively poorly documented. This is particularly true of montane settings where variations between uptake and emission of atmospheric methane have been observed. Whilst most of these ecosystems appear to function as net sinks for atmospheric methane, some act as considerable sources. In regions like the Andes, humid montane forests are extensive and a better understanding of the magnitude and controls on soil-atmosphere methane exchange is required. We report methane fluxes from upper montane cloud forest (2811 - 2962 m asl), lower montane cloud forest (1532 - 1786 m asl), and premontane forest (1070 - 1088 m asl) soils in south-eastern Peru. Between 1000 and 3000 m asl, mean annual air temperature and total annual precipitation decrease from 24 ° C and 5000 mm to 12 ° C and 1700 mm. The study region experiences a pronounced wet season between October and April. Monthly measurements of soil-atmosphere gas exchange, soil moisture, soil temperature, soil oxygen concentration, available ammonium and available nitrate were made from February 2011 in the upper and lower montane cloud forests and July 2011 in the premontane forest to June 2013. These soils acted as sinks for atmospheric methane with mean net fluxes for wet and dry season, respectively, of -2.1 (0.2) and -1.5 (0.1) mg CH4 m-2 d-1 in the upper montane forest; -1.5 (0.2) and -1.4 (0.1) mg CH4 m-2 d-1in the lower montane forest; and -0.3 (0.2) and -0.2 (0.2) mg CH4 m-2 d-1 in the premontane forest. Spatial variations among forest types were related to available nitrate and water-filled pore space suggesting that nitrate inhibition of oxidation or constraints on the diffusional supply of methane to methanotrophic communities may be important controls on methane cycling in these soils. Seasonality in methane exchange, with weaker uptake related to increased water-filled pore space and soil temperature during the wet season, was only apparent in the upper montane forest. Differences in patterns of soil-atmosphere methane exchange and environmental conditions here and in previous studies of similar ecosystems allow us to speculate that the interaction between soil structure and rainfall regimes may help explain observed variability.

An upper limit on Early Mars atmospheric pressure from small ancient craters

NASA Astrophysics Data System (ADS)

Kite, E. S.; Williams, J.; Lucas, A.; Aharonson, O.

2012-12-01

Planetary atmospheres brake, ablate, and disrupt small asteroids and comets, filtering out small hypervelocity surface impacts and causing fireballs, airblasts, meteors, and meteorites. Hypervelocity craters <1 km diameter on Earth are typically caused by irons (because stones are more likely to break up), and the smallest hypervelocity craters near sea-level on Earth are ~20 m in diameter. 'Zap pits' as small as 30 microns are known from the airless moon, but the other airy worlds show the effects of progressively thicker atmospheres:- the modern Mars atmosphere is marginally capable of removing >90% of the kinetic energy of >240 kg iron impactors; Titan's paucity of small craters is consistent with a model predicting atmospheric filtering of craters smaller than 6-8km; and on Venus, craters below ~20 km diameter are substantially depleted. Changes in atmospheric CO2 concentration are believed to be the single most important control on Mars climate evolution and habitability. Existing data requires an early epoch of massive atmospheric loss to space; suggests that the present-day rate of escape to space is small; and offers only limited evidence for carbonate formation. Existing evidence has not led to convergence of atmosphere-evolution models, which must balance poorly understood fluxes from volcanic degassing, surface weathering, and escape to space. More direct measurements are required in order to determine the history of CO2 concentrations. Wind erosion and tectonics exposes ancient surfaces on Mars, and the size-frequency distribution of impacts on these surfaces has been previously suggested as a proxy time series of Mars atmospheric thickness. We will present a new upper limit on Early Mars atmospheric pressure using the size-frequency distribution of 20-100m diameter ancient craters in Aeolis Dorsa, validated using HiRISE DTMs, in combination with Monte Carlo simulations of the effect of paleo-atmospheres of varying thickness on the crater flux. These craters are interbedded with river deposits, and so the atmospheric state they record corresponds to an era when Mars was substantially wetter than the present, probably >3.7 Ga. An important caveat is that our technique cannot exclude atmospheric collapse-reinflation cycles on timescales much shorter than the sedimentary basin-filling time, so it sets an upper limit on the density of a thick stable paleoatmosphere. We will discuss our results in relation to previous estimates of ancient atmospheric pressure, and place new constraints on models of Early Mars climate.

Atmospheric Chemistry Data Products

NASA Technical Reports Server (NTRS)

2003-01-01

This presentation poster covers data products from the Distributed Active Archive Center (DAAC) of the Goddard Earth Sciences (GES) Data and Information Services Center (DISC). Total Ozone Mapping Spectrometer products (TOMS) introduced in the presentation include TOMS Version 8 as well as Aura, which provides 25 years of TOMS and Upper Atmosphere Research Satellite (UARS) data. The presentation lists a number of atmospheric chemistry and dynamics data sets at DAAC.

Additional flux of particles and albedo-electrons in upper atmosphere

NASA Technical Reports Server (NTRS)

Aitbaev, F. B.; Dyuisembaev, B. M.; Kolomeets, E. V.

1985-01-01

The results are presented of the Monte Carlo simulation of albedo flux from the dense layers of the Earth's atmosphere and the dependence of angular distribution on the rigidity of geomagnetic cut off and additional flux of particles at the depth in the atmosphere 15-20 g/sq sm. Influence of geomagnetic field on the propagation of charged particles was not taken into account.

MAVEN Atlas V Launch

NASA Image and Video Library

2013-11-18

The United Launch Alliance Atlas V rocket with NASA’s Mars Atmosphere and Volatile EvolutioN (MAVEN) spacecraft launches from the Cape Canaveral Air Force Station Space Launch Complex 41, Monday, Nov. 18, 2013, Cape Canaveral, Florida. NASA’s Mars-bound spacecraft, the Mars Atmosphere and Volatile EvolutioN, or MAVEN, is the first spacecraft devoted to exploring and understanding the Martian upper atmosphere. Photo Credit: (NASA/Bill Ingalls)

NASA/MSFC FY-82 atmospheric processes research review

NASA Technical Reports Server (NTRS)

Turner, R. E. (Compiler)

1982-01-01

The NASA/MSFC FY-82 Atmospheric Processes Research Program was reviewed. The review covered research tasks in the areas of upper atmosphere, global weather, and severe storms and local weather. Also included was research on aviation safety environmental hazards. The research project summaries, in narrative outline form, supplied by the individual investigators together with the agenda and other information about the review are presented.

Atmospheric free-space coherent optical communications with adaptive optics

NASA Astrophysics Data System (ADS)

Ting, Chueh; Zhang, Chengyu; Yang, Zikai

2017-02-01

Free-space coherent optical communications have a potential application to offer last mile bottleneck solution in future local area networks (LAN) because of their information carrier, information security and license-free status. Coherent optical communication systems using orthogonal frequency division multiplexing (OFDM) digital modulation are successfully demonstrated in a long-haul tens Giga bits via optical fiber, but they are not yet available in free space due to atmospheric turbulence-induced channel fading. Adaptive optics is recognized as a promising technology to mitigate the effects of atmospheric turbulence in free-space optics. In this paper, a free-space coherent optical communication system using an OFDM digital modulation scheme and adaptive optics (FSO OFDM AO) is proposed, a Gamma-Gamma distribution statistical channel fading model for the FSO OFDM AO system is examined, and FSO OFDM AO system performance is evaluated in terms of bit error rate (BER) versus various propagation distances.

Young planets under extreme UV irradiation. I. Upper atmosphere modelling of the young exoplanet K2-33b

NASA Astrophysics Data System (ADS)

Kubyshkina, D.; Lendl, M.; Fossati, L.; Cubillos, P. E.; Lammer, H.; Erkaev, N. V.; Johnstone, C. P.

2018-04-01

The K2-33 planetary system hosts one transiting 5 R⊕ planet orbiting the young M-type host star. The planet's mass is still unknown, with an estimated upper limit of 5.4 MJ. The extreme youth of the system (<20 Myr) gives the unprecedented opportunity to study the earliest phases of planetary evolution, at a stage when the planet is exposed to an extremely high level of high-energy radiation emitted by the host star. We perform a series of 1D hydrodynamic simulations of the planet's upper atmosphere considering a range of possible planetary masses, from 2 to 40 M⊕, and equilibrium temperatures, from 850 to 1300 K, to account for internal heating as a result of contraction. We obtain temperature profiles mostly controlled by the planet's mass, while the equilibrium temperature has a secondary effect. For planetary masses below 7-10 M⊕, the atmosphere is subject to extremely high escape rates, driven by the planet's weak gravity and high thermal energy, which increase with decreasing mass and/or increasing temperature. For higher masses, the escape is instead driven by the absorption of the high-energy stellar radiation. A rough comparison of the timescales for complete atmospheric escape and age of the system indicates that the planet is more massive than 10 M⊕.

Retrieval of CO2 and N2 in the Martian thermosphere using dayglow observations by IUVS on MAVEN

NASA Astrophysics Data System (ADS)

Evans, J. S.; Stevens, M. H.; Lumpe, J. D.; Schneider, N. M.; Stewart, A. I. F.; Deighan, J.; Jain, S. K.; Chaffin, M. S.; Crismani, M.; Stiepen, A.; McClintock, W. E.; Holsclaw, G. M.; Lefèvre, F.; Lo, D. Y.; Clarke, J. T.; Eparvier, F. G.; Thiemann, E. M. B.; Chamberlin, P. C.; Bougher, S. W.; Bell, J. M.; Jakosky, B. M.

2015-11-01

We present direct number density retrievals of carbon dioxide (CO2) and molecular nitrogen (N2) for the upper atmosphere of Mars using limb scan observations during October and November 2014 by the Imaging Ultraviolet Spectrograph on board NASA's Mars Atmosphere and Volatile EvolutioN (MAVEN) spacecraft. We use retrieved CO2 densities to derive temperature variability between 170 and 220 km. Analysis of the data shows (1) low-mid latitude northern hemisphere CO2 densities at 170 km vary by a factor of about 2.5, (2) on average, the N2/CO2 increases from 0.042 ± 0.017 at 130 km to 0.12 ± 0.06 at 200 km, and (3) the mean upper atmospheric temperature is 324 ± 22 K for local times near 14:00.

Upper and Middle Atmospheric Density Modeling Requirements for Spacecraft Design and Operations

NASA Technical Reports Server (NTRS)

Davis, M. H. (Editor); Smith, R. E. (Editor); Johnson, D. L. (Editor)

1987-01-01

Presented and discussed are concerns with applications of neutral atmospheric density models to space vehicle engineering design and operational problems. The area of concern which the atmospheric model developers and the model users considered, involved middle atmosphere (50 to 90 km altitude) and thermospheric (above 90 km) models and their engineering application. Engineering emphasis involved areas such as orbital decay and lifetime prediction along with attitude and control studies for different types of space and reentry vehicles.

Carbon dioxide in the atmosphere. [and other research projects

NASA Technical Reports Server (NTRS)

Johnson, F. S.

1974-01-01

Research projects for the period ending September 15, 1973 are reported as follows: (1) the abundances of carbon dioxide in the atmosphere, and the processes by which it is released from carbonate deposits in the earth and then transferred to organic material by photosynthesis; the pathways for movement of carbon and oxygen through the atmosphere; (2) space science computation assistance by PDP computer; the performance characteristics and user instances; (3) OGO-6 data analysis studies of the variations of nighttime ion temperature in the upper atmosphere.

Cassini's Grand Finale Science Highlights

NASA Astrophysics Data System (ADS)

Spilker, Linda

2017-10-01

After 13 years in orbit, the Cassini-Huygens Mission to Saturn ended in a science-rich blaze of glory. Cassini returned its final bits of unique science data on September 15, 2017, as it plunged into Saturn's atmosphere satisfying planetary protection requirements. Cassini's Grand Finale covered a period of roughly five months and ended with the first time exploration of the region between the rings and planet.The final close flyby of Titan in late April 2017 propelled Cassini across Saturn’s main rings and into its Grand Finale orbits; 22 orbits that repeatedly dove between Saturn’s innermost rings and upper atmosphere making Cassini the first spacecraft to explore this region. The last orbit turned the spacecraft into the first Saturn upper atmospheric probe.The Grand Finale orbits provided highest resolution observations of both the rings and Saturn, and in-situ sampling of the ring particle composition, Saturn's atmosphere, plasma, and innermost radiation belts. The gravitational field was measured to unprecedented accuracy, providing information on the interior structure of the planet, winds in the deeper atmosphere, and mass of the rings. The magnetic field provided insight into the physical nature of the magnetic dynamo and structure of the internal magnetic field. The ion and neutral mass spectrometer sampled the upper atmosphere for molecules that escape the atmosphere in addition to molecules originating from the rings. The cosmic dust analyzer directly sampled the composition from different parts of the main rings for the first time. Fields and particles instruments directly measured the plasma environment between the rings and planet.Science highlights and new mysteries gleaned to date from the Grand Finale orbits will be discussed.The research described in this paper was carried out in part at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration. Copyright 2017 California Institute of Technology. Government sponsorship is acknowledged.

Probing Venus' polar upper atmosphere in situ: Preliminary results of the Venus Express Atmospheric Drag Experiment (VExADE).

NASA Astrophysics Data System (ADS)

Rosenblatt, Pascal; Bruinsma, Sean; Mueller-Wodarg, Ingo; Haeusler, Bernd

On its highly elliptical 24 hour orbit around Venus, the Venus Express (VEx) spacecraft briefly reaches a pericenter altitude of nominally 250 km. Recently, however, dedicated and intense radio tracking campaigns have taken place in August 2008 (campaign1), October 2009 (cam-paign2), February and April 2010 (campaign3), for which the pericenter altitude was lowered to about 175 km in order to be able to probe the upper atmosphere of Venus above the North Pole for the first time ever in-situ. As the spacecraft experiences atmospheric drag, its trajectory is measurably perturbed during the pericenter pass, allowing us to infer total atmospheric mass density at the pericenter altitude. The GINS software (Géodésie par Intégration Numérique e e Simultanées) is used to accurately reconstruct the orbital motion of VEx through an iterative least-squares fitting process to the Doppler tracking data. The drag acceleration is modelled using an initial atmospheric density model (VTS model, A. Hedin). A drag scale factor is estimated for each pericenter pass, which scales Hedin's density model in order to best fit the radio tracking data. About 20 density scale factors have been obtained mainly from the second and third VExADE campaigns, which indicate a lower density by a factor of about one-third than Hedin's model predicts. These first ever polar density measurements at solar minimum have allowed us to construct a diffusive equilibrium density model for Venus' thermosphere, constrained in the lower thermosphere primarily by SPICAV-SOIR measurements and above 175 km by the VExADE drag measurements. The preliminary results of the VExADE cam-paigns show that it is possible to obtain reliable estimates of Venus' upper atmosphere densities at an altitude of around 175 km. Future VExADE campaigns will benefit from the planned further lowering of VEx pericenter altitude to below 170 Km.

Ionospheric modification using relativistic electron beams

NASA Technical Reports Server (NTRS)

Banks, Peter M.; Fraser-Smith, Anthony C.; Gilchrist, B. E.

1990-01-01

The recent development of comparatively small electron linear accelerators (linacs) now makes possible a new class of ionospheric modification experiments using beams of relativistic electrons. These experiments can potentially provide much new information about the interactions of natural relativistic electrons with other particles in the upper atmosphere, and it may also make possible new forms of ionization structures extending down from the lower ionosphere into the largely un-ionized upper atmosphere. The consequences of firing a pulsed 1 A, 5 Mev electron beam downwards into the upper atmosphere are investigated. If a small pitch angle with respect to the ambient geomagnetic field is selected, the beam produces a narrow column of substantial ionization extending down from the source altitude to altitudes of approximately 40 to 45 km. This column is immediately polarized by the natural middle atmosphere fair weather electric field and an increasingly large potential difference is established between the column and the surrounding atmosphere. In the regions between 40 to 60 km, this potential can amount to many tens of kilovolts and the associated electric field can be greater than the field required for breakdown and discharge. Under these conditions, it may be possible to initiate lightning discharges along the initial ionization channel. Filamentation may also occur at the lower end to drive further currents in the partially ionized gases of the stratosphere. Such discharges would derive their energy from the earth-ionosphere electrical system and would be sustained until plasma depletion and/or electric field reduction brought the discharge under control. It is likely that this artificially-triggered lightning would produce measurable low-frequency radiation.

The role of nutricline depth in regulating the ocean carbon cycle.

PubMed

Cermeño, Pedro; Dutkiewicz, Stephanie; Harris, Roger P; Follows, Mick; Schofield, Oscar; Falkowski, Paul G

2008-12-23

Carbon uptake by marine phytoplankton, and its export as organic matter to the ocean interior (i.e., the "biological pump"), lowers the partial pressure of carbon dioxide (pCO(2)) in the upper ocean and facilitates the diffusive drawdown of atmospheric CO(2). Conversely, precipitation of calcium carbonate by marine planktonic calcifiers such as coccolithophorids increases pCO(2) and promotes its outgassing (i.e., the "alkalinity pump"). Over the past approximately 100 million years, these two carbon fluxes have been modulated by the relative abundance of diatoms and coccolithophores, resulting in biological feedback on atmospheric CO(2) and Earth's climate; yet, the processes determining the relative distribution of these two phytoplankton taxa remain poorly understood. We analyzed phytoplankton community composition in the Atlantic Ocean and show that the distribution of diatoms and coccolithophorids is correlated with the nutricline depth, a proxy of nutrient supply to the upper mixed layer of the ocean. Using this analysis in conjunction with a coupled atmosphere-ocean intermediate complexity model, we predict a dramatic reduction in the nutrient supply to the euphotic layer in the coming century as a result of increased thermal stratification. Our findings indicate that, by altering phytoplankton community composition, this causal relationship may lead to a decreased efficiency of the biological pump in sequestering atmospheric CO(2), implying a positive feedback in the climate system. These results provide a mechanistic basis for understanding the connection between upper ocean dynamics, the calcium carbonate-to-organic C production ratio and atmospheric pCO(2) variations on time scales ranging from seasonal cycles to geological transitions.

Steering of Upper Ocean Currents and Fronts by the Topographically Constrained Abyssal Circulation

DTIC Science & Technology

2008-07-06

a) Mean surface dynamic height relative to 1000 m from version 2.5 of the Generalized Digital Environmental Model ( GDEM ) oceanic climatology, an...NLOM simulations in comparison to the mean surface dynamic height with respect to 1000 m from the Generalized Digital Environmental Model ( GDEM ...the Kuroshio pathway east of Japan, giving much better agreement with the pathway in the GDEM climatology. Dynamics of the topographic impact on

An assessment of the utility of a non-metric digital camera for measuring standing trees

Treesearch

Neil Clark; Randolph H. Wynne; Daniel L. Schmoldt; Matthew F. Winn

2000-01-01

Images acquired with a commercially available digital camera were used to make measurements on 20 red oak (Quercus spp.) stems. The ranges of diameter at breast height (DBH) and height to a 10 cm upper-stem diameter were 16-66 cm and 12-20 m, respectively. Camera stations located 3, 6, 9, 12, and 15 m from the stem were studied to determine the best distance to be...

Digital simulation of a communication link for Pioneer Saturn Uranus atmospheric entry probe, part 1

NASA Technical Reports Server (NTRS)

Hinrichs, C. A.

1975-01-01

A digital simulation study is presented for a candidate modulator/demodulator design in an atmospheric scintillation environment with Doppler, Doppler rate, and signal attenuation typical of the conditions of an outer planet atmospheric probe. The simulation results indicate that the mean channel error rate with and without scintillation are similar to theoretical characterizations of the link. The simulation gives information for calculating other channel statistics and generates a quantized symbol stream on magnetic tape from which error correction decoding is analyzed. Results from the magnetic tape data analyses are also included. The receiver and bit synchronizer are modeled in the simulation at the level of hardware component parameters rather than at the loop equation level and individual hardware parameters are identified. The atmospheric scintillation amplitude and phase are modeled independently. Normal and log normal amplitude processes are studied. In each case the scintillations are low pass filtered. The receiver performance is given for a range of signal to noise ratios with and without the effects of scintillation. The performance is reviewed for critical reciever parameter variations.

Point-of-Care Quantitative Measure of Glucose-6-Phosphate Dehydrogenase Enzyme Deficiency.

PubMed

Bhutani, Vinod K; Kaplan, Michael; Glader, Bertil; Cotten, Michael; Kleinert, Jairus; Pamula, Vamsee

2015-11-01

Widespread newborn screening on a point-of-care basis could prevent bilirubin neurotoxicity in newborns with glucose-6-phosphate dehydrogenase (G6PD) deficiency. We evaluated a quantitative G6PD assay on a digital microfluidic platform by comparing its performance with standard clinical methods. G6PD activity was measured quantitatively by using digital microfluidic fluorescence and the gold standard fluorescence biochemical test on a convenience sample of 98 discarded blood samples. Twenty-four samples were designated as G6PD deficient. Mean ± SD G6PD activity for normal samples using the digital microfluidic method and the standard method, respectively, was 9.7 ± 2.8 and 11.1 ± 3.0 U/g hemoglobin (Hb), respectively; for G6PD-deficient samples, it was 0.8 ± 0.7 and 1.4 ± 0.9 U/g Hb. Bland-Altman analysis determined a mean difference of -0.96 ± 1.8 U/g Hb between the digital microfluidic fluorescence results and the standard biochemical test results. The lower and upper limits for the digital microfluidic platform were 4.5 to 19.5 U/g Hb for normal samples and 0.2 to 3.7 U/g Hb for G6PD-deficient samples. The lower and upper limits for the Stanford method were 5.5 to 20.7 U/g Hb for normal samples and 0.1 to 2.8 U/g Hb for G6PD-deficient samples. The measured activity discriminated between G6PD-deficient samples and normal samples with no overlap. Pending further validation, a digital microfluidics platform could be an accurate point-of-care screening tool for rapid newborn G6PD screening. Copyright © 2015 by the American Academy of Pediatrics.

Digital Simulation Of Precise Sensor Degradations Including Non-Linearities And Shift Variance

NASA Astrophysics Data System (ADS)

Kornfeld, Gertrude H.

1987-09-01

Realistic atmospheric and Forward Looking Infrared Radiometer (FLIR) degradations were digitally simulated. Inputs to the routine are environmental observables and the FLIR specifications. It was possible to achieve realism in the thermal domain within acceptable computer time and random access memory (RAM) requirements because a shift variant recursive convolution algorithm that well describes thermal properties was invented and because each picture element (pixel) has radiative temperature, a materials parameter and range and altitude information. The computer generation steps start with the image synthesis of an undegraded scene. Atmospheric and sensor degradation follow. The final result is a realistic representation of an image seen on the display of a specific FLIR.

Remote sensing of Earth's atmosphere and surface using a digital array scanned interferometer: A new type of imaging spectrometer

NASA Technical Reports Server (NTRS)

Hammer, Philip D.; Valero, Francisco P. J.; Peterson, David L.; Smith, William Hayden

1991-01-01

The capabilities of the digital array scanned interferometer (DASI) class of instruments for measuring terrestrial radiation fields over the visible to mid-infrared are evaluated. DASI's are capable of high throughput, sensitivity and spectral resolution and have the potential for field-of-view spatial discrimination (an imaging spectrometer). The simplicity of design and operation of DASI's make them particularly suitable for field and airborne platform based remote sensing. The long term objective is to produce a versatile field instrument which may be applied toward a variety of atmospheric and surface studies. The operation of DASI and its advantages over other spectrometers are discussed.

The nature of large-scale turbulence in the Jovian atmosphere

NASA Technical Reports Server (NTRS)

Mitchell, J. L.

1982-01-01

The energetics and spectral characteristis of quasi-geostrophic turbulence in Jupiter's atmosphere are examined using sequences of Voyager images and infrared temperature soundings. Using global wind measurements momentum transports associated with zonally symmetric stresses and turbulent stresses are quantified. Though a strong up-gradient flux of momentum by eddies was observed, measurements do not preclude the possibility that symmetric stresses play a critical role in maintaining the mean zonal circulation. Strong correlation between the observed meridional distribution of eddy-scale kinetic energy and available potential energy suggests coupling between the observed cloudtop turbulent motions and the upper tropospheric thermodynamics. An Oort energy budget for Jupiter's upper troposphere is formulated.

Probing Protoplanetary Disk Upper Atmospheres for Heating and Dust Settling Using Synthetic CO Spectra

NASA Astrophysics Data System (ADS)

Lewis, Josiah; Brittain, S. D.

2010-01-01

CO emission is a useful probe of the warm gas distribution in the planet forming regions of disks around Herbig Ae/Be stars. We model UV fluoresced and thermally excited CO in the circumstellar disks of several HAeBes. We find indications of dust settling in the upper atmospheres of HD 141569 and HD 7048 and a correlation between PAH luminosity and gas heating in these two systems. This project was funded by a partnership between the National Science Foundation (NSF AST-0552798), Research Experiences for Undergraduates (REU), and the Department of Defense (DoD) ASSURE (Awards to Stimulate and Support Undergraduate Research Experiences) programs.

Afghanistan: Politics, Elections, and Government Performance

DTIC Science & Technology

2014-11-04

which 10 seats are elected by Kuchi nomads ) and a selected 102 seat upper house (Meshrano Jirga, House of Elders). The upper house is selected as...Ghazni; 9 in Badakhshan, Konduz, and Faryab; 8 in Helmand; and 2 to 6 in the remaining provinces. Ten are reserved for Kuchis ( nomads ). Afghanistan...Islamic clergy. One of his vice presidential running mates was Ismail Khan, a faction leader discussed above. The ticket polled in the single digits

Comparing upper tropospheric humidity data from microwave satellite instruments and tropical radiosondes

NASA Astrophysics Data System (ADS)

Moradi, Isaac; Buehler, Stefan A.; John, Viju O.; Eliasson, Salomon

2010-12-01

Atmospheric humidity plays an important role in the Earth's climate. Microwave satellite data provide valuable humidity observations in the upper troposphere with global coverage. In this study, we compare upper tropospheric humidity (UTH) retrieved from the Advanced Microwave Sounding Unit and the Microwave Humidity Sounder against radiosonde data measured at four of the central facilities of the Atmospheric Radiation Measurement program. The Atmospheric Radiative Transfer Simulator (ARTS) was used to simulate satellite brightness temperatures from the radiosonde profiles. Strong ice clouds were filtered out, as their influence on microwave measurements leads to incorrect UTH values. Day and night radiosonde profiles were analyzed separately to take into account the radiosonde radiation bias. The comparison between radiosonde and satellite is most meaningful for data in cloud-free, nighttime conditions and with a time difference of less than 2 hr. We found good agreement between the two data sets. The satellite data were slightly moister than the radiosonde data, with a mean difference of 1%-2.3% relative humidity (RH), depending on the radiosonde site. Monthly gridded data were also compared and showed a slightly larger mean difference of up to 3.3% RH, which can be explained by sampling issues.

Present state of knowledge of the upper atmosphere 1988: An assessment report

NASA Astrophysics Data System (ADS)

Watson, R. T.; Prather, M. J.; Kurylo, M. J.

1988-06-01

This document was issued in response to the Clean Air Act Amendments of 1977, Public Law 95-95, mandating that NASA and other key agencies submit biennial reports to Congress and EPA. NASA is to report on the state of our knowledge of the upper atmosphere, particularly the stratosphere. This is the sixth ozone assessment report submitted to Congress and the concerned regulatory agencies. Part 1 contains an outline of the NASA Upper Atmosphere Research Program and summaries of the research efforts supported during the last two years. An assessment is presented of the state of knowledge as of March 15, 1988 when the Ozone Trends Panel, organized by NASA and co-sponsored by the World Meteorological Organization, NOAA, FAA and the United Nations Environment Program released an executive summary of its findings from a critical in-depth study involving over 100 scientists from 12 countries. Chapter summaries of the International Ozone Trends Panel Report form the major part of this report. Two other sections are Model Predictions of Future Ozone Change and Chemical Kinetics and Photochemical Data for Use in Stratospheric Modeling. Each of these sections and the report in its entirety were peer reviewed.

Ocean acidification in a geoengineering context

PubMed Central

Williamson, Phillip; Turley, Carol

2012-01-01

Fundamental changes to marine chemistry are occurring because of increasing carbon dioxide (CO2) in the atmosphere. Ocean acidity (H+ concentration) and bicarbonate ion concentrations are increasing, whereas carbonate ion concentrations are decreasing. There has already been an average pH decrease of 0.1 in the upper ocean, and continued unconstrained carbon emissions would further reduce average upper ocean pH by approximately 0.3 by 2100. Laboratory experiments, observations and projections indicate that such ocean acidification may have ecological and biogeochemical impacts that last for many thousands of years. The future magnitude of such effects will be very closely linked to atmospheric CO2; they will, therefore, depend on the success of emission reduction, and could also be constrained by geoengineering based on most carbon dioxide removal (CDR) techniques. However, some ocean-based CDR approaches would (if deployed on a climatically significant scale) re-locate acidification from the upper ocean to the seafloor or elsewhere in the ocean interior. If solar radiation management were to be the main policy response to counteract global warming, ocean acidification would continue to be driven by increases in atmospheric CO2, although with additional temperature-related effects on CO2 and CaCO3 solubility and terrestrial carbon sequestration. PMID:22869801

Present state of knowledge of the upper atmosphere 1988: An assessment report

NASA Technical Reports Server (NTRS)

Watson, R. T.; Prather, M. J.; Kurylo, M. J.

1988-01-01

This document was issued in response to the Clean Air Act Amendments of 1977, Public Law 95-95, mandating that NASA and other key agencies submit biennial reports to Congress and EPA. NASA is to report on the state of our knowledge of the upper atmosphere, particularly the stratosphere. This is the sixth ozone assessment report submitted to Congress and the concerned regulatory agencies. Part 1 contains an outline of the NASA Upper Atmosphere Research Program and summaries of the research efforts supported during the last two years. An assessment is presented of the state of knowledge as of March 15, 1988 when the Ozone Trends Panel, organized by NASA and co-sponsored by the World Meteorological Organization, NOAA, FAA and the United Nations Environment Program released an executive summary of its findings from a critical in-depth study involving over 100 scientists from 12 countries. Chapter summaries of the International Ozone Trends Panel Report form the major part of this report. Two other sections are Model Predictions of Future Ozone Change and Chemical Kinetics and Photochemical Data for Use in Stratospheric Modeling. Each of these sections and the report in its entirety were peer reviewed.

Upper Atmosphere Research Satellite (UARS) trade analysis

NASA Technical Reports Server (NTRS)

Fox, M. M.; Nebb, J.

1983-01-01

The Upper Atmosphere Research Satellite (UARS) which will collect data pertinent to the Earth's upper atmosphere is described. The collected data will be sent to the central data handling facility (CDHF) via the UARS ground system and the data will be processed and distributed to the remote analysis computer systems (RACS). An overview of the UARS ground system is presented. Three configurations were developed for the CDHF-RACS system. The CDHF configurations are discussed. The IBM CDHF configuration, the UNIVAC CDHF configuration and the vax cluster CDHF configuration are presented. The RACS configurations, the IBM RACS configurations, UNIVAC RACS and VAX RACS are detailed. Due to the large on-line data estimate to approximately 100 GB, a mass storage system is considered essential to the UARS CDHF. Mass storage systems were analyzed and the Braegan ATL, the RCA optical disk, the IBM 3850 and the MASSTOR M860 are discussed. It is determined that the type of mass storage system most suitable to UARS is the automated tape/cartridge device. Two devices of this type, the IBM 3850 and the MASSTOR MSS are analyzed and the applicable tape/cartridge device is incorporated into the three CDHF-RACS configurations.

An analysis of the vertical structure equation for arbitrary thermal profiles

NASA Technical Reports Server (NTRS)

Cohn, Stephen E.; Dee, Dick P.

1989-01-01

The vertical structure equation is a singular Sturm-Liouville problem whose eigenfunctions describe the vertical dependence of the normal modes of the primitive equations linearized about a given thermal profile. The eigenvalues give the equivalent depths of the modes. The spectrum of the vertical structure equation and the appropriateness of various upper boundary conditions, both for arbitrary thermal profiles were studied. The results depend critically upon whether or not the thermal profile is such that the basic state atmosphere is bounded. In the case of a bounded atmosphere it is shown that the spectrum is always totally discrete, regardless of details of the thermal profile. For the barotropic equivalent depth, which corresponds to the lowest eigen value, upper and lower bounds which depend only on the surface temperature and the atmosphere height were obtained. All eigenfunctions are bounded, but always have unbounded first derivatives. It was proved that the commonly invoked upper boundary condition that vertical velocity must vanish as pressure tends to zero, as well as a number of alternative conditions, is well posed. It was concluded that the vertical structure equation always has a totally discrete spectrum under the assumptions implicit in the primitive equations.

An analysis of the vertical structure equation for arbitrary thermal profiles

NASA Technical Reports Server (NTRS)

Cohn, Stephen E.; Dee, Dick P.

1987-01-01

The vertical structure equation is a singular Sturm-Liouville problem whose eigenfunctions describe the vertical dependence of the normal modes of the primitive equations linearized about a given thermal profile. The eigenvalues give the equivalent depths of the modes. The spectrum of the vertical structure equation and the appropriateness of various upper boundary conditions, both for arbitrary thermal profiles were studied. The results depend critically upon whether or not the thermal profile is such that the basic state atmosphere is bounded. In the case of a bounded atmosphere it is shown that the spectrum is always totally discrete, regardless of details of the thermal profile. For the barotropic equivalent depth, which corresponds to the lowest eigen value, upper and lower bounds which depend only on the surface temperature and the atmosphere height were obtained. All eigenfunctions are bounded, but always have unbounded first derivatives. It was proved that the commonly invoked upper boundary condition that vertical velocity must vanish as pressure tends to zero, as well as a number of alternative conditions, is well posed. It was concluded that the vertical structure equation always has a totally discrete spectrum under the assumptions implicit in the primitive equations.

New upper limits for atmospheric constituents on Io

NASA Technical Reports Server (NTRS)

Fink, U.; Larson, H. P.; Gautier, T. N., III

1976-01-01

A spectrum of Io from 0.86 to 2.7 microns with a resolution of 3.36 per cm and a signal to rms noise ratio of 120 is presented. No absorptions due to any atmospheric constituents on Io could be found in the spectrum. Upper limits of 0.12 cm-atm for NH3, 0.12 cm-atm for CH4, 0.4 cm-atm for N2O, and 24 cm-atm for H2S were determined. Laboratory spectra of ammonia frosts as a function of temperature were compared with the spectrum of Io and showed this frost not to be present at the surface of Io. A search for possible resonance lines of carbon, silicon, and sulfur, as well as the 1.08-micron line of helium, proved negative. Upper emission limits of 60, 18, 27, and 60 kilorayleighs, respectively, were established for these lines.

Quality Control of Wind Data from 50-MHz Doppler Radar Wind Profiler

NASA Technical Reports Server (NTRS)

Vacek, Austin

2016-01-01

Upper-level wind profiles obtained from a 50-MHz Doppler Radar Wind Profiler (DRWP) instrument at Kennedy Space Center are incorporated in space launch vehicle design and day-of-launch operations to assess wind effects on the vehicle during ascent. Automated and manual quality control (QC) techniques are implemented to remove spurious data in the upper-level wind profiles caused from atmospheric and non-atmospheric artifacts over the 2010-2012 period of record (POR). By adding the new quality controlled profiles with older profiles from 1997-2009, a robust database will be constructed of upper-level wind characteristics. Statistical analysis will determine the maximum, minimum, and 95th percentile of the wind components from the DRWP profiles over recent POR and compare against the older database. Additionally, this study identifies specific QC flags triggered during the QC process to understand how much data is retained and removed from the profiles.

Quality Control of Wind Data from 50-MHz Doppler Radar Wind Profiler

NASA Technical Reports Server (NTRS)

Vacek, Austin

2015-01-01

Upper-level wind profiles obtained from a 50-MHz Doppler Radar Wind Profiler (DRWP) instrument at Kennedy Space Center are incorporated in space launch vehicle design and day-of-launch operations to assess wind effects on the vehicle during ascent. Automated and manual quality control (QC) techniques are implemented to remove spurious data in the upper-level wind profiles caused from atmospheric and non-atmospheric artifacts over the 2010-2012 period of record (POR). By adding the new quality controlled profiles with older profiles from 1997-2009, a robust database will be constructed of upper-level wind characteristics. Statistical analysis will determine the maximum, minimum, and 95th percentile of the wind components from the DRWP profiles over recent POR and compare against the older database. Additionally, this study identifies specific QC flags triggered during the QC process to understand how much data is retained and removed from the profiles.

VOLATILE LOSS AND CLASSIFICATION OF KUIPER BELT OBJECTS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Johnson, R. E.; Schmidt, C.; Oza, A.

Observations indicate that some of the largest Kuiper Belt Objects (KBOs) have retained volatiles in the gas phase (e.g., Pluto), while others have surface volatiles that might support a seasonal atmosphere (e.g., Eris). Since the presence of an atmosphere can affect their reflectance spectra and thermal balance, Schaller and Brown examined the role of volatile escape driven by solar heating of the surface. Guided by recent simulations, we estimate the loss of primordial N{sub 2} for several large KBOs, accounting for escape driven by UV/EUV heating of the upper atmosphere as well as by solar heating of the surface. Formore » the latter we present new simulations and for the former we scale recent detailed simulations of escape from Pluto using the energy limited escape model validated recently by molecular kinetic simulations. Unlike what has been assumed to date, we show that unless the N{sub 2} atmosphere is thin (<∼10{sup 18} N{sub 2} cm{sup −2}) and/or the radius small (<∼200–300 km), escape is primarily driven by the UV/EUV radiation absorbed in the upper atmosphere. This affects the discussion of the relationship between atmospheric loss and the observed surface properties for a number of the KBOs examined. Our long-term goal is to connect detailed atmospheric loss simulations with a model for volatile transport for individual KBOs.« less

Ion Neutral Mass Spectrometer Measurements from Titan

NASA Technical Reports Server (NTRS)

Waite, J. H., Jr.; Niemann, H.; Yelle, R. V.; Kasprzak, W.; Cravens, T.; Luhmann, J.; McNutt, R.; Ip, W.-H.; Gell, D.; Muller-Wordag, I. C. F.

2005-01-01

Introduction: The Ion Neutral Mass Spectrometer (INMS) aboard the Cassini orbiter has obtained the first in situ composition measurements of the neutral densities of molecular nitrogen, methane, argon, and a host of stable carbon-nitrile compounds in its first flyby of Titan. The bulk composition and thermal structure of the moon s upper atmosphere do not appear to be changed since the Voyager flyby in 1979. However, the more sensitive techniques provided by modern in-situ mass spectrometry also give evidence for large-spatial-scale large-amplitude atmospheric waves in the upper atmosphere and for a plethora of stable carbon-nitrile compounds above 1174 km. Furthermore, they allow the first direct measurements of isotopes of nitrogen, carbon, and argon, which provide interesting clues about the evolution of the atmosphere. The atmosphere was first accreted as ammonia and ammonia ices from the Saturn sub-nebula. Subsequent photochemistry likely converted the atmosphere into molecular nitrogen. The early atmosphere was 1.5 to 5 times more substantial and was lost via escape over the intervening 4.5 billion years due to the reduced gravity associated with the relatively small mass of Titan. Carbon in the form of methane has continued to outgas over time from the interior with much of it being deposited in the form of complex hydrocarbons on the surface and some of it also being lost to space.

Midnight Temperature Maximum (MTM) in Whole Atmosphere Model (WAM) Simulations

DTIC Science & Technology

2016-04-14

naturally strongly dissipative medium, eliminating the need for ‘‘ sponge layers’’ and extra numerical dissipation often imposed in upper layers to...stabilize atmospheric model codes. WAM employs no ‘‘ sponge layers’’ and remains stable using a substantially reduced numerical Rayleigh friction coeffi

Early harvest: The upper atmosphere and cosmic rays

NASA Technical Reports Server (NTRS)

1980-01-01

Achievements in space science through 1958 are summarized. Topics discussed are: the scheduling of V-2 flights; the development of newer rockets; the testing of spaceborne instruments; the seeking of financial support for space research; and the problems of international cooperation. Special emphasis is placed on atmospheric sounding.

Development of wide band digital receiver for atmospheric radars using COTS board based SDR

NASA Astrophysics Data System (ADS)

Yasodha, Polisetti; Jayaraman, Achuthan; Thriveni, A.

2016-07-01

Digital receiver extracts the received echo signal information, and is a potential subsystem for atmospheric radar, also referred to as wind profiling radar (WPR), which provides the vertical profiles of 3-dimensional wind vector in the atmosphere. This paper presents the development of digital receiver using COTS board based Software Defined Radio technique, which can be used for atmospheric radars. The developmental work is being carried out at National Atmospheric Research Laboratory (NARL), Gadanki. The digital receiver consists of a commercially available software defined radio (SDR) board called as universal software radio peripheral B210 (USRP B210) and a personal computer. USRP B210 operates over a wider frequency range from 70 MHz to 6 GHz and hence can be used for variety of radars like Doppler weather radars operating in S/C bands, in addition to wind profiling radars operating in VHF, UHF and L bands. Due to the flexibility and re-configurability of SDR, where the component functionalities are implemented in software, it is easy to modify the software to receive the echoes and process them as per the requirement suitable for the type of the radar intended. Hence, USRP B210 board along with the computer forms a versatile digital receiver from 70 MHz to 6 GHz. It has an inbuilt direct conversion transceiver with two transmit and two receive channels, which can be operated in fully coherent 2x2 MIMO fashion and thus it can be used as a two channel receiver. Multiple USRP B210 boards can be synchronized using the pulse per second (PPS) input provided on the board, to configure multi-channel digital receiver system. RF gain of the transceiver can be varied from 0 to 70 dB. The board can be controlled from the computer via USB 3.0 interface through USRP hardware driver (UHD), which is an open source cross platform driver. The USRP B210 board is connected to the personal computer through USB 3.0. Reference (10 MHz) clock signal from the radar master oscillator is used to lock the board, which is essential for deriving Doppler information. Input from the radar analog receiver is given to one channel of USRP B210, which is down converted to baseband. 12-bit ADC present on the board digitizes the signal and produces I (in-phase) and Q (quadrature-phase) data. The maximum sampling rate possible is about 61 MSPS. The I and Q (time series) data is sent to PC via USB 3.0, where the signal processing is carried out. The online processing steps include decimation, range gating, decoding, coherent integration and FFT computation (optional). The processed data is then stored in the hard disk. C++ programming language is used for developing the real time signal processing. Shared memory along with multi threading is used to collect and process data simultaneously. Before implementing the real time operation, stand alone test of the board was carried out through GNU radio software and the base band output data obtained is found satisfactory. Later the board is integrated with the existing Lower Atmospheric Wind Profiling radar at NARL. The radar receive IF output at 70 MHz is given to the board and the real-time radar data is collected. The data is processed off-line and the range-doppler spectrum is obtained. Online processing software is under progress.

Energy Deposition Processes in Titan's Upper Atmosphere

NASA Technical Reports Server (NTRS)

Sittler, Edward C., Jr.; Bertucci, Cesar; Coates, Andrew; Cravens, Tom; Dandouras, Iannis; Shemansky, Don

2008-01-01

Most of Titan's atmospheric organic and nitrogen chemistry, aerosol formation, and atmospheric loss are driven from external energy sources such as Solar UV, Saturn's magnetosphere, solar wind and galactic cosmic rays. The Solar UV tends to dominate the energy input at lower altitudes of approximately 1100 km but which can extend down to approximately 400 km, while the plasma interaction from Saturn's magnetosphere, Saturn's magnetosheath or solar wind are more important at higher altitudes of approximately 1400 km, but the heavy ion plasma [O(+)] of approximately 2 keV and energetic ions [H(+)] of approximately 30 keV or higher from Saturn's magnetosphere can penetrate below 950km. Cosmic rays with energies of greater than 1 GeV can penetrate much deeper into Titan's atmosphere with most of its energy deposited at approximately 100 km altitude. The haze layer tends to dominate between 100 km and 300 km. The induced magnetic field from Titan's interaction with the external plasma can be very complex and will tend to channel the flow of energy into Titan's upper atmosphere. Cassini observations combined with advanced hybrid simulations of the plasma interaction with Titan's upper atmosphere show significant changes in the character of the interaction with Saturn local time at Titan's orbit where the magnetosphere displays large and systematic changes with local time. The external solar wind can also drive sub-storms within the magnetosphere which can then modify the magnetospheric interaction with Titan. Another important parameter is solar zenith angle (SZA) with respect to the co-rotation direction of the magnetospheric flow. Titan's interaction can contribute to atmospheric loss via pickup ion loss, scavenging of Titan's ionospheric plasma, loss of ionospheric plasma down its induced magnetotail via an ionospheric wind, and non-thermal loss of the atmosphere via heating and sputtering induced by the bombardment of magnetospheric keV ions and electrons. This energy input evidently drives the large positive and negative ions observed below approximately 1100 km altitude with ion masses exceeding 10,000 daltons. We refer to these ions as seed particles for the aerosols observed below 300 km altitude. These seed particles can be formed, for example, from the polymerization of acetylene (C2H2) and benzene (C6H6) molecules in Titan's upper atmosphere to form polycyclic aromatic hydrocarbons (PAH) and/or fullerenes (C60). In the case of fullerenes, which are hollow spherical carbon shells, magnetospheric keV [O(+)] ions can become trapped inside the fullerenes and eventually find themselves inside the aerosols as free oxygen. The aerosols are then expected to fall to Titan's surface as polymerized hydrocarbons with trapped free oxygen where unknown surface chemistry can take place.

Sediment Microbial Enzyme Activity as an Indicator of Nutrient Limitation in the Great Rivers of the Upper Mississippi Basin

EPA Science Inventory

We compared extracellular enzyme activity (EEA) of microbial assemblages in river sediments at 447 sites along the Upper Mississippi, Missouri, and Ohio Rivers with sediment and water chemistry, atmospheric deposition of nitrogen and sulfate, and catchment land uses. The sites re...

Assessing the dynamics of the upper soil layer relative to soil management practices

USDA-ARS?s Scientific Manuscript database

The upper layer of the soil is the critical interface between the soil and the atmosphere and is the most dynamic in response to management practices. One of the soil properties is the stability of the aggregates because this property controls infiltration of water and exchange of gases. An aggregat...

Production of gamma rays with energies greater than 30 MeV in the atmosphere

NASA Technical Reports Server (NTRS)

Thompson, D.; Fichtel, C.; Kniffen, D.

1974-01-01

A three-dimensional study of atmospheric gamma rays with energy greater than 30 MeV has been carried out. Experimental results were obtained from four balloon flights from Palestine, Texas, with a 15 cm by 15 cm digitized wire grid spark chamber. The energy spectrum for downward-moving gamma rays steepens with increasing atmospheric depth. Near the top of the atmosphere, the spectrum steepens with increasing zenith angle. Experimental results compare reasonably well with a three-dimensional Monte Carlo calculation of atmospheric gamma ray production. Inclusion of upward-moving gamma rays makes possible the use of atmospheric secondaries for in-flight calibration of satellite gamma ray detectors.

The Chromospheric Lyman-Alpha Spectro-Polarimeter (CLASP)

NASA Technical Reports Server (NTRS)

Ishikawa, Shin-nosuke; Kano, R.; Kobayashi, K.; Bando, T.; Narukage, N..; Ishikawa, R.; Kubo, M.; Katsukawa, Y.; Suematsu, Y.; Hara, H.;

The realist interpretation of the atmosphere

NASA Astrophysics Data System (ADS)

Anduaga, Aitor

The discovery of a clearly stratified structure of layers in the upper atmosphere has been--and still is--invoked too often as the great paradigm of atmospheric sciences in the 20th century. Behind this vision, an emphasis--or better, an overstatement--on the reality of the concept of layer lies. One of the few historians of physics who have not ignored this phenomenon of reification, C. Stewart Gillmor, attributed it to--somewhat ambiguous-- cultural (or perhaps, more generally, contextual) factors, though he never specified their nature. In this essay, I aim to demonstrate that, in the interwar years, most radiophysicists and some atomic physicists, for reasons principally related to extrinsic influences and to a lesser extent to internal developments of their own science, fervidly embraced a realist interpretation of the ionosphere. We will focus on the historical circumstances in which a specific social and commercial environment came to exert a strong influence on upper atmospheric physicists, and in which realism as a product validating the "truth" of certain practices and beliefs arose. This realist commitment I attribute to the mutual reinforcement of atmospheric physics and commercial and imperial interests in long-distance communications.

The New Horizons Ultraviolet Solar Occultation by Pluto's Atmosphere

NASA Astrophysics Data System (ADS)

Young, L. A.; Kammer, J.; Steffl, A.; Gladstone, R.; Summers, M. E.; Strobel, D. F.; Hinson, D. P.; Stern, A.; Weaver, H. A., Jr.; Olkin, C.; Ennico Smith, K.; McComas, D. J.

2017-12-01

The Alice instrument on NASA's New Horizons spacecraft observed an ultraviolet solar occultation by Pluto's atmosphere on 2015 July 14, as the spacecraft flew nearly diametrically though the solar shadow. The resulting dataset was a time-series of spectra from 52 to 187 nm with a spectral resolution of 0.3 nm. From these, we derived line-of-sight abundances and local number densities for the major species (N2 and CH4) and minor hydrocarbons (C2H2, C2H4, C2H6), and line-of-sight optical depth and extinction coefficients for the haze. Analysis of these data imply that (1) temperatures in Pluto's upper atmosphere were colder than expected before the New Horizons flyby, with upper atmospheric temperatures near 65-68 K, and subsequently lower escape rates, dominated by CH4 escape over N2; (2) the lower atmosphere was very stable, placing the homopause within 12 km of the surface, (3) the abundance profiles of the "C2Hx hydrocarbons" had non-exponential density profiles that compared favorably with models for hydrocarbon production near 300-400 km and haze condensation near 200 km, and (4) haze had an extinction coefficient approximately proportional to N2 density.

ATLAS 1: Encountering Planet Earth

NASA Technical Reports Server (NTRS)

Shea, Charlotte; Mcmahan, Tracy; Accardi, Denise; Tygielski, Michele; Mikatarian, Jeff; Wiginton, Margaret (Editor)

1984-01-01

Several NASA science programs examine the dynamic balance of sunlight, atmosphere, water, land, and life that governs Earth's environment. Among these is a series of Space Shuttle-Spacelab missions, named the Atmospheric Laboratory for Applications and Science (ATLAS). During the ATLAS missions, international teams of scientists representing many disciplines combine their expertise to seek answers to complex questions about the atmospheric and solar conditions that sustain life on Earth. The ATLAS program specifically investigates how Earth's middle atmosphere and upper atmospheres and climate are affected by both the Sun and by products of industrial and agricultural activities on Earth.

Development and application of a non-Gaussian atmospheric turbulence model for use in flight simulators

NASA Technical Reports Server (NTRS)

Reeves, P. M.; Campbell, G. S.; Ganzer, V. M.; Joppa, R. G.

1974-01-01

A method is described for generating time histories which model the frequency content and certain non-Gaussian probability characteristics of atmospheric turbulence including the large gusts and patchy nature of turbulence. Methods for time histories using either analog or digital computation are described. A STOL airplane was programmed into a 6-degree-of-freedom flight simulator, and turbulence time histories from several atmospheric turbulence models were introduced. The pilots' reactions are described.

Water-table and potentiometric-surface altitudes in the upper glacial, Magothy, and Lloyd aquifers of Long Island, New York, April–May 2016

USGS Publications Warehouse

Como, Michael D.; Finkelstein, Jason S.; Rivera, Simonette L.; Monti, Jack; Busciolano, Ronald J.

2018-06-06

The U.S. Geological Survey, in cooperation with State and local agencies, systematically collects groundwater data at varying measurement frequencies to monitor the hydrologic conditions on Long Island, New York. Each year during April and May, the U.S. Geological Survey completes a synoptic survey of water levels to define the spatial distribution of the water table and potentiometric surfaces within the three main water-bearing units underlying Long Island—the upper glacial, Magothy, and Lloyd aquifers—and the hydraulically connected Jameco and North Shore aquifers. These data and the maps constructed from them are commonly used in studies of the hydrology of Long Island and are used by water managers and suppliers for aquifer management and planning purposes.Water-level measurements made in 424 monitoring wells (observation and supply wells), 13 streamgages, and 2 lake gages across Long Island during April–May 2016 were used to prepare the maps in this report. Groundwater measurements were made by the wetted-tape or electric-tape method to the nearest hundredth of a foot. Contours of water-table and potentiometric-surface altitudes were created using the groundwater measurements. The water-table contours were interpreted using water-level data collected from 275 observation wells and 1 supply well screened in the upper glacial aquifer and the shallow Magothy aquifer and 13 streamgages and 2 lake gages. The potentiometric-surface contours of the Magothy aquifer were interpreted from measurements at 88 wells (61 observation wells and 27 supply wells) screened in the middle to deep Magothy aquifer and the contiguous and hydraulically connected Jameco aquifer. The potentiometric-surface contours of the Lloyd aquifer were interpreted from measurements at 60 wells (55 observation wells and 5 supply wells) screened in the Lloyd aquifer and the contiguous and hydraulically connected North Shore aquifer. Many of the supply wells are in continuous operation and, therefore, were turned off for a minimum of 24 hours before measurements were made to allow the water levels in the wells to recover to ambient (nonpumping) conditions. Full recovery time at some of these supply wells can exceed 24 hours; therefore, water levels measured at these wells are assumed to be less accurate than those measured at observation wells, which are not pumped. In addition to pumping stresses, density differences (saline water) also lower the water levels measured in certain wells. Recent water-quality data are lacking in these wells; therefore, a conversion to freshwater head could not be performed accurately and was not attempted. In this report, all water-level altitudes are referenced to the National Geodetic Vertical Datum of 1929 (NGVD 29).The land surface altitude, or topography, was obtained from the National Oceanic and Atmospheric Administration. The data were collected using light detection and ranging (lidar) and were used to produce a three-dimensional digital elevation model. The lidar data have a horizontal accuracy of 1.38 feet and a vertical accuracy of 0.40 foot at a 95-percent confidence level for the “open terrain” land-cover category. The digital elevation model was developed jointly by the National Oceanic and Atmospheric Administration and the U.S. Geological Survey as part of the Disaster Relief Appropriations Act of 2013. Land surface altitude is referenced to the North American Vertical Datum of 1988 (NAVD 88). On Long Island, NAVD 88 is approximately 1 foot higher than NGVD 29.Hydrographs are included on these maps for selected wells that have continuous digital recording equipment, and each hydrograph includes the water level measured during the synoptic survey. These hydrographs are representative of the 2016 water year and show the changes throughout that period; a water year is the 12-month period from October 1 to September 30 and is designated by the year in which it ends.

History of Chandra X-Ray Observatory

NASA Image and Video Library

2001-07-04

Giving scientists their first look, Chandra observed x-rays produced by fluorescent radiation from oxygen atoms of the Sun in the sparse upper atmosphere of Mars, about 120 kilometers (75 miles) above its surface. The x-ray power detected from the Martian atmosphere is very small, amounting to only 4 megawatts, comparable to the x-ray power of about ten thousand medical x-ray machines. At the time of the Chandra observation, a huge dust storm developed on Mars that covered about one hemisphere, later to cover the entire planet. This hemisphere rotated out of view over the 9-hour observation, but no change was observed in the x-ray intensity indicating that the dust storm did not affect the upper atmosphere. Scientists also observed a halo of x-rays extending out to 7,000 kilometers above the surface of Mars believed to be produced by collisions of ions racing away from the Sun (the solar wind).

KSC-2013-3366

NASA Image and Video Library

2013-08-21

CAPE CANAVERAL, Fla. – Inside the Payload Hazardous Servicing Facility at NASA's Kennedy Space Center in Florida, a technician inspects a cell from one of the electricity-producing solar arrays for the Mars Atmosphere and Volatile Evolution, or MAVEN, spacecraft. MAVEN is being prepared for its scheduled launch in November from Cape Canaveral Air Force Station, Fla. atop a United Launch Alliance Atlas V rocket. Positioned in an orbit above the Red Planet, MAVEN will study the upper atmosphere of Mars in unprecedented detail. For more information, visit: http://www.nasa.gov/mission_pages/maven/main/index.html Photo credit: NASA/Jim Grossmann MAVEN is being prepared inside the facility for its scheduled November launch aboard a United Launch Alliance Atlas V rocket to Mars. Positioned in an orbit above the Red Planet, MAVEN will study the upper atmosphere of Mars in unprecedented detail. Photo credit: NASA/Jim Grossmann

KSC-2013-3367

NASA Image and Video Library

2013-08-21

CAPE CANAVERAL, Fla. – Inside the Payload Hazardous Servicing Facility at NASA's Kennedy Space Center in Florida, a technician repairs a cell from one of the electricity-producing solar arrays for the Mars Atmosphere and Volatile Evolution, or MAVEN, spacecraft. MAVEN is being prepared for its scheduled launch in November from Cape Canaveral Air Force Station, Fla. atop a United Launch Alliance Atlas V rocket. Positioned in an orbit above the Red Planet, MAVEN will study the upper atmosphere of Mars in unprecedented detail. For more information, visit: http://www.nasa.gov/mission_pages/maven/main/index.html Photo credit: NASA/Jim Grossmann MAVEN is being prepared inside the facility for its scheduled November launch aboard a United Launch Alliance Atlas V rocket to Mars. Positioned in an orbit above the Red Planet, MAVEN will study the upper atmosphere of Mars in unprecedented detail. Photo credit: NASA/Jim Grossmann

KSC-2013-3372

NASA Image and Video Library

2013-08-21

CAPE CANAVERAL, Fla. – Inside the Payload Hazardous Servicing Facility at NASA's Kennedy Space Center in Florida, a technician cleans a cell from one of the electricity-producing solar arrays for the Mars Atmosphere and Volatile Evolution, or MAVEN, spacecraft. MAVEN is being prepared for its scheduled launch in November from Cape Canaveral Air Force Station, Fla. atop a United Launch Alliance Atlas V rocket. Positioned in an orbit above the Red Planet, MAVEN will study the upper atmosphere of Mars in unprecedented detail. For more information, visit: http://www.nasa.gov/mission_pages/maven/main/index.html Photo credit: NASA/Jim Grossmann MAVEN is being prepared inside the facility for its scheduled November launch aboard a United Launch Alliance Atlas V rocket to Mars. Positioned in an orbit above the Red Planet, MAVEN will study the upper atmosphere of Mars in unprecedented detail. Photo credit: NASA/Jim Grossmann

A Numerical Study of Tropical Sea-Air Interactions Using a Cloud Resolving Model Coupled with an Ocean Mixed-Layer Model

NASA Technical Reports Server (NTRS)

Shie, Chung-Lin; Tao, Wei-Kuo; Johnson, Dan; Simpson, Joanne; Li, Xiaofan; Sui, Chung-Hsiung; Einaudi, Franco (Technical Monitor)

2001-01-01

Coupling a cloud resolving model (CRM) with an ocean mixed layer (OML) model can provide a powerful tool for better understanding impacts of atmospheric precipitation on sea surface temperature (SST) and salinity. The objective of this study is twofold. First, by using the three dimensional (3-D) CRM-simulated (the Goddard Cumulus Ensemble model, GCE) diabatic source terms, radiation (longwave and shortwave), surface fluxes (sensible and latent heat, and wind stress), and precipitation as input for the OML model, the respective impact of individual component on upper ocean heat and salt budgets are investigated. Secondly, a two-way air-sea interaction between tropical atmospheric climates (involving atmospheric radiative-convective processes) and upper ocean boundary layer is also examined using a coupled two dimensional (2-D) GCE and OML model. Results presented here, however, only involve the first aspect. Complete results will be presented at the conference.

Atmospheric mass-loss of extrasolar planets orbiting magnetically active host stars

NASA Astrophysics Data System (ADS)

Lalitha, Sairam; Schmitt, J. H. M. M.; Dash, Spandan

2018-06-01

Magnetic stellar activity of exoplanet hosts can lead to the production of large amounts of high-energy emission, which irradiates extrasolar planets, located in the immediate vicinity of such stars. This radiation is absorbed in the planets' upper atmospheres, which consequently heat up and evaporate, possibly leading to an irradiation-induced mass-loss. We present a study of the high-energy emission in the four magnetically active planet-bearing host stars, Kepler-63, Kepler-210, WASP-19, and HAT-P-11, based on new XMM-Newton observations. We find that the X-ray luminosities of these stars are rather high with orders of magnitude above the level of the active Sun. The total XUV irradiation of these planets is expected to be stronger than that of well-studied hot Jupiters. Using the estimated XUV luminosities as the energy input to the planetary atmospheres, we obtain upper limits for the total mass- loss in these hot Jupiters.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bony, Sandrine; Stevens, Bjorn; Coppin, David

General circulation models show that as the surface temperature increases, the convective anvil clouds shrink. By analyzing radiative–convective equilibrium simulations, our work shows that this behavior is rooted in basic energetic and thermodynamic properties of the atmosphere: As the climate warms, the clouds rise and remain at nearly the same temperature, but find themselves in a more stable atmosphere; this enhanced stability reduces the convective outflow in the upper troposphere and decreases the anvil cloud fraction. By warming the troposphere and increasing the upper-tropospheric stability, the clustering of deep convection also reduces the convective outflow and the anvil cloud fraction.more » When clouds are radiatively active, this robust coupling between temperature, high clouds, and circulation exerts a positive feedback on convective aggregation and favors the maintenance of strongly aggregated atmospheric states at high temperatures. This stability iris mechanism likely contributes to the narrowing of rainy areas as the climate warms. Whether or not it influences climate sensitivity requires further investigation.« less

Composition and thermal profiles of the Jovian upper atmosphere determined by the Voyager ultraviolet stellar occultation experiment

NASA Technical Reports Server (NTRS)

Festou, M. C.; Atreya, S. K.; Donahue, T. M.; Sandel, B. R.; Shemansky, D. E.; Broadfoot, A. L.

1981-01-01

During the occultation of the star Regulus (B7 type) by Jupiter as seen from the Voyager 2 spacecraft on July 9, 1979, two absorbing regions were detected. Between 911 and 1200 A, H2 was absorbing over a 600 km altitude range. Above 1300 A, the rapid increase of the absorption by the hydrocarbons was observed over an altitude interval of approximately 100 km with a height resolution of 3 km. The analysis of these absorption features has provided the height profiles of molecular hydrogen, methane, ethane, and acetylene, as well as the thermal profile in the upper atmosphere of Jupiter. Combining the Voyager ultraviolet spectrometer results with other data, such as those obtained by the Voyager infrared and radioscience instruments, has yielded a comprehensive model of the composition and structure of the atmosphere of Jupiter.

Chandra Image Gives First Look at Mars Emitted X-Rays

NASA Technical Reports Server (NTRS)

2001-01-01

Giving scientists their first look, Chandra observed x-rays produced by fluorescent radiation from oxygen atoms of the Sun in the sparse upper atmosphere of Mars, about 120 kilometers (75 miles) above its surface. The x-ray power detected from the Martian atmosphere is very small, amounting to only 4 megawatts, comparable to the x-ray power of about ten thousand medical x-ray machines. At the time of the Chandra observation, a huge dust storm developed on Mars that covered about one hemisphere, later to cover the entire planet. This hemisphere rotated out of view over the 9-hour observation, but no change was observed in the x-ray intensity indicating that the dust storm did not affect the upper atmosphere. Scientists also observed a halo of x-rays extending out to 7,000 kilometers above the surface of Mars believed to be produced by collisions of ions racing away from the Sun (the solar wind).

New observations of molecular nitrogen in the Martian upper atmosphere by IUVS on MAVEN

NASA Astrophysics Data System (ADS)

Stevens, M. H.; Evans, J. S.; Schneider, N. M.; Stewart, A. I. F.; Deighan, J.; Jain, S. K.; Crismani, M.; Stiepen, A.; Chaffin, M. S.; McClintock, W. E.; Holsclaw, G. M.; Lefèvre, F.; Lo, D. Y.; Clarke, J. T.; Montmessin, F.; Bougher, S. W.; Jakosky, B. M.

2015-11-01

We identify molecular nitrogen (N2) emissions in the Martian upper atmosphere using the Imaging Ultraviolet Spectrograph (IUVS) on NASA's Mars Atmosphere and Volatile EvolutioN (MAVEN) mission. We report the first observations of the N2 Lyman-Birge-Hopfield (LBH) bands at Mars and confirm the tentative identification of the N2 Vegard-Kaplan (VK) bands. We retrieve N2 density profiles from the VK limb emissions and compare calculated limb radiances between 90 and 210 km against both observations and predictions from a Mars general circulation model (GCM). Contrary to earlier analyses using other satellite data, we find that N2 abundances exceed GCM results by about a factor of 2 at 130 km but are in agreement at 150 km. The analysis and interpretation are enabled by a linear regression method used to extract components of UV spectra from IUVS limb observations.

KSC-2013-3365

NASA Image and Video Library

2013-08-21

CAPE CANAVERAL, Fla. – Inside the Payload Hazardous Servicing Facility at NASA's Kennedy Space Center in Florida, a technician inspects a cell from one of the electricity-producing solar arrays for the Mars Atmosphere and Volatile Evolution, or MAVEN, spacecraft. MAVEN is being prepared for its scheduled launch in November from Cape Canaveral Air Force Station, Fla. atop a United Launch Alliance Atlas V rocket. Positioned in an orbit above the Red Planet, MAVEN will study the upper atmosphere of Mars in unprecedented detail. For more information, visit: http://www.nasa.gov/mission_pages/maven/main/index.html Photo credit: NASA/Jim Grossmann MAVEN is being prepared inside the facility for its scheduled November launch aboard a United Launch Alliance Atlas V rocket to Mars. Positioned in an orbit above the Red Planet, MAVEN will study the upper atmosphere of Mars in unprecedented detail. Photo credit: NASA/Jim Grossmann

Investigation of a nozzle instability on an F100 engine equipped with a digital electronic engine control

NASA Technical Reports Server (NTRS)

Burcham, F. W., Jr.; Zeller, J. R.

1984-01-01

An instability in the nozzle of the F100 engine, equipped with a digital electronic engine control (DEEC), was observed during a flight evaluation on an F-15 aircraft. The instability occurred in the upper left hand corner (ULMC) of the flight envelope during augmentation. The instability was not predicted by stability analysis, closed-loop simulations of the the engine, or altitude testing of the engine. The instability caused stalls and augmentor blowouts. The nozzle instability and the altitude testing are described. Linear analysis and nonlinear digital simulation test results are presented. Software modifications on further flight test are discussed.

Determining the role of TiO/VO in hot exoplanet atmospheres

NASA Astrophysics Data System (ADS)

Evans, Thomas

2016-10-01

The role of TiO and VO in ultra hot (>2000K) gas giant atmospheres is a major unresolved issue in the exoplanet field. At these temperatures, TiO and VO are known to be important absorbers in the atmospheres of M/L dwarfs and have been theorized to play an important role in irradiated gas giants. To date, however, TiO/VO has not been securely detected in a planetary atmosphere, despite numerous searches. One possibility is that the upper atmospheres of highly irradiated planets are typically depleted of TiO/VO by cold-trapping at lower altitudes or rain-out on the relatively cool nightside. Using WFC3 G141 and ground-based photometry, we have recently published a transmission spectrum for WASP-121b (T~2400K) showing new evidence for absorption by TiO/VO. Our observations also yielded a high confidence (5.4 sigma) detection of the 1.4 micron H2O absorption band. The TiO/VO claim, however, remains tentative, as it currently hinges upon broadband photometry measurements obtained from the ground at relatively low signal-to-noise. If TiO/VO is present it will have significant implications for the overall physics and chemistry of the atmosphere, including the likely production of a strong thermal inversion in the upper atmosphere. I will describe the follow-up observations we are currently pursuing in order to confirm or rule out TiO/VO in the atmosphere of WASP-121b and in doing so address a long-standing mystery of exoplanet atmospheres.

Moist Climates with an Ineffective Cold Trap

NASA Astrophysics Data System (ADS)

Ding, F.; Pierrehumbert, R.

2016-12-01

The tropopause of the Earth's atmosphere behaves as a cold trap, limiting the water vapor transport from the humid sea surface to the dry regions in the atmosphere including both the upper atmosphere and the highly sub-saturated places in the free troposphere. It is hypothesized that during some period of time on Earth, the cold trap mechanism would become less effective, due to either a reduced nitrogen inventory in the atmosphere or high surface temperatures. An ineffective cold trap favors a moist upper atmosphere and will lead to rapid water loss by the ultraviolet photodissociation, which was well studied in one-dimensional models. However, the effect of an ineffective cold trap on 3D climates has not yet received much attention. Here we explore the 3D effect with an idealized general circulation model especially designed for studying condensible-rich atmospheres. We consider two scenarios based on the orbital configuration of the planet. (a) With Earth's orbital parameters, sub-saturation in the free troposphere is difficult to be produced by large-scale atmospheric flows, which implies that an ineffective cold trap also favors the onset of the runaway greenhouse. (b) For synchronous-rotating planets, water vapor is easier to be transported to the nightside, building up an atmosphere with similar column water mass as the dayside. For extrasolar habitable planets detections around M dwarfs in the future, if the water vapor contrast between the day and night side could be provided by the phase-resolved emission spectra, the contrast might be useful as a constraint for evaluating the mass of the non-condensible components in the atmosphere.

The Data Rescue @ Home Project

NASA Astrophysics Data System (ADS)

Stickler, A.; Allan, R.; Valente, M. A.; Tinz, B.; Brönnimann, S.

2012-04-01

Climate science as a whole as well as reanalyses as a special case can significantly profit from the recovery, imaging and digitisation of historical observations. The importance of this fact is reflected in large, global data rescue projects and initiatives such as the Atmospheric Circulation Reconstructions over the Earth (ACRE, www.met-acre.org) or the EU FP7 ERA-CLIM project (www.era-clim.eu). From the time before 1957, there are still large amounts of surface data e.g. from former colonies and from overseas territories of European countries )e.g. Portugal, France and Germany) that need to be rescued. Also in case of the very early upper-air observations before the 1930s, even Europe and North America still hold an important quantity of data to be recovered in digital form. Here, we present the web platform "Data Rescue @ Home" (www.data-rescue-at-home.org), which has been developed at ETH Zurich and Oeschger Centre for Climate Change Research, and which has been designed to take advantage of the voluntary assistance of the thousands of people on the web who are interested in climate or old weather data. On the website, these volunteers can enter meteorological data shown on digital images into entry masks that resemble the original. By registering, the users get access to their personal digitisation statistics and help optimising the project. At the moment, 4 digitisation projects are online: One project is dealing with German upper-air data from the Second World War period. In a second project, station data from Tulagi (Solomon Islands) is being digitised. Finally, two collaborative projects have been included: One in cooperation with the Instituto Dom Luiz (Univ. Lisbon, Portugal), where Portuguese station data from Angra (Azores) is digitised, and a further one in cooperation with the German Meteorological Service (DWD), in which precipitation data from former German colonies is being digitised. On our poster, we will report on the status of the projects, technical details of the data preparation, and give examples of how the platform can be used by external partners to digitise large amounts of data at relatively low cost.

Digital fabrication as an instructional technology for supporting upper elementary and middle school science and mathematics education

NASA Astrophysics Data System (ADS)

Tillman, Daniel

The purpose of this three-paper manuscript dissertation was to study digital fabrication as an instructional technology for supporting elementary and middle school science and mathematics education. Article one analyzed the effects of digital fabrication activities that were designed to contextualize mathematics education at a summer mathematics enrichment program for upper elementary and middle school students. The primary dependent variables studied were the participants' knowledge of mathematics and science content, attitudes towards STEM (science, technology, engineering, and mathematics) and STEM-related careers. Based upon the data collected, three results were presented as having justifiable supporting empirical evidence: (1) The digital fabrication activities, combined with the other mathematics activities at the enrichment program, resulted in non-significant overall gains in students' mathematics test scores and attitudes towards STEM. (2) The digital fabrication activities, combined with the other mathematics activities at the enrichment program, resulted in noteworthy gains on the "Probability & Statistics" questions. (3) Some students who did poorly on the scored paper test on mathematics and science content were nonetheless nominated by their teachers as demonstrating meritorious distinction during the digital fabrication activities (termed "Great Thinkers" by the 5th-grade teachers). Article two focused on how an instructional technology course featuring digital fabrication activities impacted (1) preservice elementary teachers' efficacy beliefs about teaching science, and (2) their attitudes and understanding of how to include instructional technology and digital fabrication activities into teaching science. The research design compared two sections of a teaching with technology course featuring digital fabrication activities to another section of the same course that utilized a media cycle framework (Bull & Bell, 2005) that did not feature digital fabrication activities. Based upon analysis of the data collected, two main results were determined to have justifiable supporting empirical evidence: (1) After the instructional technology course featuring digital fabrication activities, the participants reported statistically significant overall gains in science teaching efficacy beliefs. (2) When asked to describe their future plans for using three instructional technologies in their teaching, the top five most mentioned instructional technologies were: interactive whiteboards, video, class website, interactive online timeline, and digital fabrication. Of the participants that mentioned digital fabrication, the specific content areas mentioned were: history (four out of eight students mentioned), social studies (two out of eight), and science, math, engineering, and technology were each mentioned once. Article three assessed the impact of a series of lessons incorporating a NASA-themed transmedia book featuring digital fabrication activities on 5th-grade students who had been recognized as advanced in mathematics. The main dependent variables studied were the students' knowledge of science content from the Virginia Standards of Learning, attitude towards science, and student reported likes and dislikes about the project. Based upon analysis of the data collected, three main results were presented: (1) Students demonstrated significant positive gains in correct answers to questions on the topic of "Force, Matter, Energy, & Motion" from pretest to posttest. (2) There were nonsignificant gains reported by students on the attitude survey questions about attitude towards science, but this was chiefly because of one question that was significantly impacted in a negative direction. (3) Students articulated five main categories of likes and six main categories of dislikes of the experience, thereby providing insight into their own perception of some of the affordances and constraints of the educational activities. The five topics mentioned most often by students as self-reported likes about the experience included: hands-on activities including building, making, or designing (18 of 29 students mentioned; 62.1%), experimenting (9 of 29; 31.0%), presenting (9 of 29; 31.0%), drawing (6 of 29; 20.7%), and working in groups (6 of 29; 20.7%). The six topics most mentioned by students as self-reported dislikes about the experience included: taking tests (13 of 29 students mentioned; 44.8%), drawing (7 of 29; 24.1%), confusing / too fast (4 of 29; 13.8%), class discussions (4 of 29; 13.8%), reviewing (4 of 29; 13.8%), and attitude surveys (4 of 29; 13.8%). Cumulatively these three articles aim to contribute to the body of research studying the impact of digital fabrication as an instructional technology for supporting upper elementary and middle school science and mathematics education. This goal is described in greater detail in the "Manuscript Theme" section that begins on the next page. Keywords: STEM, digital fabrication, upper elementary science education, contextual mathematics, modeling-based science instruction, transmedia books, performance assessment, preservice elementary teacher education, science teaching efficacy beliefs

Fully automated calculation of cardiothoracic ratio in digital chest radiographs

NASA Astrophysics Data System (ADS)

Cong, Lin; Jiang, Luan; Chen, Gang; Li, Qiang

2017-03-01

The calculation of Cardiothoracic Ratio (CTR) in digital chest radiographs would be useful for cardiac anomaly assessment and heart enlargement related disease indication. The purpose of this study was to develop and evaluate a fully automated scheme for calculation of CTR in digital chest radiographs. Our automated method consisted of three steps, i.e., lung region localization, lung segmentation, and CTR calculation. We manually annotated the lung boundary with 84 points in 100 digital chest radiographs, and calculated an average lung model for the subsequent work. Firstly, in order to localize the lung region, generalized Hough transform was employed to identify the upper, lower, and outer boundaries of lung by use of Sobel gradient information. The average lung model was aligned to the localized lung region to obtain the initial lung outline. Secondly, we separately applied dynamic programming method to detect the upper, lower, outer and inner boundaries of lungs, and then linked the four boundaries to segment the lungs. Based on the identified outer boundaries of left lung and right lung, we corrected the center and the declination of the original radiography. Finally, CTR was calculated as a ratio of the transverse diameter of the heart to the internal diameter of the chest, based on the segmented lungs. The preliminary results on 106 digital chest radiographs showed that the proposed method could obtain accurate segmentation of lung based on subjective observation, and achieved sensitivity of 88.9% (40 of 45 abnormalities), and specificity of 100% (i.e. 61 of 61 normal) for the identification of heart enlargements.

Sex determination by three-dimensional geometric morphometrics of craniofacial form.

PubMed

Chovalopoulou, Maria-Eleni; Valakos, Efstratios D; Manolis, Sotiris K

The purpose of the present study is to define which regions of the cranium, the upper-face, the orbits and the nasal are the most sexually dimorphic, by using three-dimensional geometric morphometric methods, and investigate the effectiveness of this method in determining sex from the shape of these regions. The study sample consisted of 176 crania of known sex (94 males, 82 females) belonging to individuals who lived in Greece during the 20(th) century. The three-dimensional co-ordinates of 31 ecto-cranial landmarks were digitized using a MicroScribe 3DX contact digitizer. Goodall's F-test was performed in order to compare statistical differences in shape between males and females. Generalized Procrustes Analysis (GPA) was used to obtain size and shape variables for statistical analysis. Shape, Size and Form analyses were carried out by logistic regression and discriminant function analysis. The results indicate that there are shape differences between the sexes in the upper-face and the orbits. The highest shape classification rate was obtained from the upper-face region. The centroid size of the caraniofacial and the orbital regions was smaller in females than males. Moreover, it was found that size is significant for sexual dimorphism in the upper-face region. As anticipated, the classification accuracy improves when both size and shape are combined. The findings presented here constitute a firm basis upon which further research can be conducted.

Assessing Atmospheric Water Injection from Oceanic Impacts

NASA Technical Reports Server (NTRS)

Pierazzo, E.

2005-01-01

Collisions of asteroids and comets with the Earth s surface are rare events that punctuate the geologic record. Due to the vastness of Earth s oceans, oceanic impacts of asteroids or comets are expected to be about 4 times more frequent than land impacts. The resulting injections of oceanic water into the upper atmosphere can have important repercussions on Earth s climate and atmospheric circulation. However, the duration and overall effect of these large injections are still unconstrained. This work addresses atmospheric injections of large amounts of water in oceanic impacts.

Solar terrestrial observatory

NASA Technical Reports Server (NTRS)

1981-01-01

Eight basic solar-terrestrial scientific objectives that benefit from the Shuttle/Platform approach and a program of measurements for each are discussed. The objectives are to understand: (1) solar variability, (2) wave-particle processes, (3) magnetosphere-ionosphere mass transport, (4) the global electric circuit, (5) upper atmospheric dynamics, (6) middle atmospheric chemistry and energetics, (7) lower atmospheric turbidity, and (8) planetary atmospheric waves. A two stage approach to a multidisciplinary payload is developed: an initial STO, that uses a single platform in a low-Earth orbit, and an advanced STO that uses two platforms in differing orbits.

Atmospheric effects on the underground muon intensity

NASA Technical Reports Server (NTRS)

Fenton, A. G.; Fenton, K. B.; Humble, J. E.; Hyland, G. B.

1985-01-01

It has previously been reported that the barometric pressure coefficient observed for muons at Poatina (vertical absorber depth 357 hg/sq cm) appears to be appreciably higher than would be expected from atmospheric absorption alone. There is a possibility that the effect is due to an upper atmospheric temperature effect arising from an inverse correlation of surface pressure with stratospheric temperature. A new proportional telescope is discussed which has been operating at Poatina since about the beginning of 83 and which has a long term stability suitable for studying variations of atmospheric origin.

11th International Conference on Atmospheric Electricity

NASA Technical Reports Server (NTRS)

Christian, H. J. (Compiler)

1999-01-01

This document contains the proceedings from the 11th International Conference on Atmospheric Electricity (ICAE 99), held June 7-11, 1999. This conference was attended by scientists and researchers from around the world. The subjects covered included natural and artificially initiated lightning, lightning in the middle and upper atmosphere (sprites and jets), lightning protection and safety, lightning detection techniques (ground, airborne, and space-based), storm physics, electric fields near and within thunderstorms, storm electrification, atmospheric ions and chemistry, shumann resonances, satellite observations of lightning, global electrical processes, fair weather electricity, and instrumentation.

Temporal and spatial distribution of metallic species in the upper atmosphere

NASA Astrophysics Data System (ADS)

Correira, John Thomas

2009-06-01

Every day the Earth is bombarded by approximately 100 tons of meteoric material. Much of this material is completely ablated on atmospheric entry, resulting in a layer of atomic metals in the upper atmosphere between 70 km - 150 km. These neutral atoms are ionized by solar radiation and charge exchange. Metal ions have a long lifetime against recombination loss, allowing them to be redistributed globally by electromagnetic forces, especially when lifted to altitudes >150 km. UV radiances from the Global Ozone Monitoring Experiment (GOME) spectrometer are used to determine long-term dayside variations of the total vertical column density below 795 km of the meteoric metal species Mg and Mg + in the upper atmosphere. A retrieval algorithm developed to determine magnesium column densities was applied to all available data from the years 1996-2001. Long term results show middle latitude dayside Mg + peaks in vertical content during the summer, while neutral Mg demonstrates a much more subtle maximum in summer. Atmospheric metal concentrations do not correlate strongly solar activity. An analysis of spatial variations shows geospatial distributions are patchy, with local regions of increased column density. To study short term variations and the role of meteor showers a time dependent mass flux rate is calculated using published estimates of meteor stream mass densities and activity profiles. An average daily mass flux rate is also calculated and used as a baseline against which shower mass flux rates are compared. These theoretical mass flux rates are then compared with GOME derived metal column densities. There appears to be little correlation between modeled meteor shower mass flux rates and changes in the observed neutral magnesium and Mg + metal column densities.

Elusive anion growth in Titan's atmosphere: Low temperature kinetics of the C3N- + HC3N reaction

NASA Astrophysics Data System (ADS)

Bourgalais, Jérémy; Jamal-Eddine, Nour; Joalland, Baptiste; Capron, Michael; Balaganesh, Muthiah; Guillemin, Jean-Claude; Le Picard, Sébastien D.; Faure, Alexandre; Carles, Sophie; Biennier, Ludovic

2016-06-01

Ion chemistry appears to be deeply involved in the formation of heavy molecules in the upper atmosphere of Titan. These large species form the seeds of the organic aerosols responsible for the opaque haze surrounding the biggest satellite of Saturn. The chemical pathways involving individual anions remain however mostly unknown. The determination of the rates of the elementary reactions with ions and the identification of the products are essential to the progress in our understanding of Titan's upper atmosphere. We have taken steps in that direction through the investigation of the low temperature reactivity of C3N- , which was tentatively identified in the spectra measured by the CAPS-ELS instrument of the Cassini spacecraft during its high altitude flybys. The reaction of this anion with HC3N, one of the most abundant trace organics in the atmosphere, has been studied over the 49-294 K temperature range in uniform supersonic flows using the CRESU technique. The proton transfer is found to be the main exit channel (>91%) of the C315N- + HC3N reaction. It remains however indistinguishable with the non-isotopically labeled C314N- reactant. The T - 1 / 2 temperature dependence of this proton transfer reaction and its global rate are reasonably well reproduced theoretically using an average dipole orientation model. A minor exit channel, reactive detachment (< 9%), has also been uncovered, although the nature of the neutral products has not been determined. It is concluded that the C314N- + HC3N reaction cannot contribute to the growth of molecular anions in the upper atmosphere of Titan. Due to the low branching into the neutral exit channel, it cannot contribute either to the growth of neutrals even assuming a complete mass transfer.

Simulating planetary wave propagation to the upper atmosphere during stratospheric warming events at different mountain wave scenarios

NASA Astrophysics Data System (ADS)

Gavrilov, Nikolai M.; Koval, Andrey V.; Pogoreltsev, Alexander I.; Savenkova, Elena N.

2018-04-01

Parameterization schemes of atmospheric normal modes (NMs) and orographic gravity waves (OGWs) have been implemented into the mechanistic Middle and Upper Atmosphere Model (MUAM) simulating atmospheric general circulation. Based on the 12-members ensemble of runs with the MUAM, a composite of the stratospheric warming (SW) has been constructed using the UK Met Office data as the lower boundary conditions. The simulation results show that OGW amplitudes increase at altitudes above 30 km in the Northern Hemisphere after the SW event. At altitudes of about 50 km, OGWs have largest amplitudes over North American and European mountain systems before and during the composite SW, and over Himalayas after the SW. Simulations demonstrate substantial (up to 50-70%) variations of amplitudes of stationary planetary waves (PWs) during and after the SW in the mesosphere-lower thermosphere of the Northern Hemisphere. Westward travelling NMs have amplitude maxima not only in the Northern, but also in the Southern Hemisphere, where these modes have waveguides in the middle and upper atmosphere. Simulated variations of PW and NM amplitudes correspond to changes in the mean zonal wind, EP-fluxes and wave refractive index at different phases of the composite SW events. Inclusion of the parameterization of OGW effects leads to decreases in amplitudes (up to 15%) of almost all SPWs before and after the SW event and their increase (up to 40-60%) after the SW in the stratosphere and mesosphere at middle and high northern latitudes. It is suggested that observed changes in NM amplitudes in the Southern Hemisphere during SW could be caused by divergence of increased southward EP-flux. This EP-flux increases due to OGW drag before SW and extends into the Southern Hemisphere.

Light in condensed matter in the upper atmosphere as the origin of homochirality: circularly polarized light from Rydberg matter.

PubMed

Holmlid, Leif

2009-01-01

Clouds of the condensed excited Rydberg matter (RM) exist in the atmospheres of comets and planetary bodies (most easily observed at Mercury and the Moon), where they surround the entire bodies. Vast such clouds are recently proposed to exist in the upper atmosphere of Earth (giving rise to the enormous features called noctilucent clouds, polar mesospheric clouds, and polar mesospheric summer radar echoes). It has been shown in experiments with RM that linearly polarized visible light scattered from an RM layer is transformed to circularly polarized light with a probability of approximately 50%. The circular Rydberg electrons in the magnetic field in the RM may be chiral scatterers. The magnetic and anisotropic RM medium acts as a circular polarizer probably by delaying one of the perpendicular components of the light wave. The delay process involved is called Rabi-flopping and gives delays of the order of femtoseconds. This strong effect thus gives intense circularly polarized visible and UV light within RM clouds. Amino acids and other chiral molecules will experience a strong interaction with this light field in the upper atmospheres of planets. The interaction will vary with the stereogenic conformation of the molecules and in all probability promote the survival of one enantiomer. Here, this strong effect is proposed to be the origin of homochirality. The formation of amino acids in the RM clouds is probably facilitated by the catalytic effect of RM.

Light in Condensed Matter in the Upper Atmosphere as the Origin of Homochirality: Circularly Polarized Light from Rydberg Matter

NASA Astrophysics Data System (ADS)

Holmlid, Leif

2009-08-01

Clouds of the condensed excited Rydberg matter (RM) exist in the atmospheres of comets and planetary bodies (most easily observed at Mercury and the Moon), where they surround the entire bodies. Vast such clouds are recently proposed to exist in the upper atmosphere of Earth (giving rise to the enormous features called noctilucent clouds, polar mesospheric clouds, and polar mesospheric summer radar echoes). It has been shown in experiments with RM that linearly polarized visible light scattered from an RM layer is transformed to circularly polarized light with a probability of approximately 50%. The circular Rydberg electrons in the magnetic field in the RM may be chiral scatterers. The magnetic and anisotropic RM medium acts as a circular polarizer probably by delaying one of the perpendicular components of the light wave. The delay process involved is called Rabi-flopping and gives delays of the order of femtoseconds. This strong effect thus gives intense circularly polarized visible and UV light within RM clouds. Amino acids and other chiral molecules will experience a strong interaction with this light field in the upper atmospheres of planets. The interaction will vary with the stereogenic conformation of the molecules and in all probability promote the survival of one enantiomer. Here, this strong effect is proposed to be the origin of homochirality. The formation of amino acids in the RM clouds is probably facilitated by the catalytic effect of RM.

Investigations of the Mars Upper Atmosphere with ExoMars Trace Gas Orbiter

NASA Astrophysics Data System (ADS)

López-Valverde, Miguel A.; Gerard, Jean-Claude; González-Galindo, Francisco; Vandaele, Ann-Carine; Thomas, Ian; Korablev, Oleg; Ignatiev, Nikolai; Fedorova, Anna; Montmessin, Franck; Määttänen, Anni; Guilbon, Sabrina; Lefevre, Franck; Patel, Manish R.; Jiménez-Monferrer, Sergio; García-Comas, Maya; Cardesin, Alejandro; Wilson, Colin F.; Clancy, R. T.; Kleinböhl, Armin; McCleese, Daniel J.; Kass, David M.; Schneider, Nick M.; Chaffin, Michael S.; López-Moreno, José Juan; Rodríguez, Julio

2018-02-01

The Martian mesosphere and thermosphere, the region above about 60 km, is not the primary target of the ExoMars 2016 mission but its Trace Gas Orbiter (TGO) can explore it and address many interesting issues, either in-situ during the aerobraking period or remotely during the regular mission. In the aerobraking phase TGO peeks into thermospheric densities and temperatures, in a broad range of latitudes and during a long continuous period. TGO carries two instruments designed for the detection of trace species, NOMAD and ACS, which will use the solar occultation technique. Their regular sounding at the terminator up to very high altitudes in many different molecular bands will represent the first time that an extensive and precise dataset of densities and hopefully temperatures are obtained at those altitudes and local times on Mars. But there are additional capabilities in TGO for studying the upper atmosphere of Mars, and we review them briefly. Our simulations suggest that airglow emissions from the UV to the IR might be observed outside the terminator. If eventually confirmed from orbit, they would supply new information about atmospheric dynamics and variability. However, their optimal exploitation requires a special spacecraft pointing, currently not considered in the regular operations but feasible in our opinion. We discuss the synergy between the TGO instruments, specially the wide spectral range achieved by combining them. We also encourage coordinated operations with other Mars-observing missions capable of supplying simultaneous measurements of its upper atmosphere.

Jupiter's Auroral Energy Input Observed by Hisaki/EXCEED and its Modulations by Io's Volcanic Activity

NASA Astrophysics Data System (ADS)

Tao, C.; Kimura, T.; Tsuchiya, F.; Murakami, G.; Yoshioka, K.; Kita, H.; Yamazaki, A.; Kasaba, Y.; Yoshikawa, I.; Fujimoto, M.

2016-12-01

Aurora is an important indicator representing the momentum transfer from the fast-rotating outer planet to the magnetosphere and the energy input into the atmosphere through the magnetosphere-ionosphere coupling. Long-term monitoring of Jupiter's northern aurora was achieved by the Extreme Ultraviolet (EUV) spectrometer called EXCEED (Extreme Ultraviolet Spectroscope for Exospheric Dynamics) onboard JAXA's Earth-orbiting planetary space telescope Hisaki until today after its launch in September 2013. We have proceeded the statistical survey of the Jupiter's auroral energy input into the upper atmosphere. The auroral electron energy is estimated using a hydrocarbon color ratio (CR) adopted for the wavelength range of EXCEED, and the emission power in the long wavelength range 138.5-144.8 nm is used as an indicator of total emitted power before hydrocarbon absorption and auroral electron energy flux. Temporal dynamic variation of the auroral intensity was detected when Io's volcanic activity and thus EUV emission from the Io plasma torus are enhanced in the early 2015. Average of the total input power over 80 days increases by 10% with sometimes sporadically more than a factor of 3 upto 7, while the CR indicates the auroral electron energy decrease by 20% during the volcanic event compared to the other period. This indicates much more increase in the current system and Joule heating which contributes heating of the upper atmosphere. We will discuss the impact of this event on the upper atmosphere and ionosphere.

Lightning driven EMP in the upper atmosphere

NASA Technical Reports Server (NTRS)

Rowland, H. L.; Fernsler, R. F.; Huba, J. D.; Bernhardt, P. A.

1995-01-01

Large lightning discharges can drive electromagnetic pulses (EMP) that cause breakdown of the neutral atmosphere between 80 and 95 km leading to order of magnitude increases in the plasma density. The increase in the plasma density leads to increased reflection and absorption, and limits the pulse strength that propagates higher into the ionosphere.

Tropospheric Waves, Jet Streams, and United States Weather Patterns. Resource Paper No. 11.

ERIC Educational Resources Information Center

Harman, Jay R.

Intended as a supplement to undergraduate college geography courses, this resource paper reviews the mechanism by which surface weather features are linked with the mid-atmospheric circulation within the westerly wind belt. Specifically, vertical atmospheric motions associated with certain aspects of the upper tropospheric flow, including jet…

VANDENBERG AIR FORCE BASE, CALIF. - At Vandenberg Air Force Base, Calif., the Pegasus launch vehicle is moved toward its hangar. The Pegasus will carry the SciSat-1 spacecraft in a 400-mile-high polar orbit to investigate processes that control the distribution of ozone in the upper atmosphere. The data from the satellite will provide Canadian and international scientists with improved measurements relating to global ozone processes and help policymakers assess existing environmental policy and develop protective measures for improving the health of our atmosphere, preventing further ozone depletion. The mission is designed to last two years.

NASA Image and Video Library

2003-06-26

VANDENBERG AIR FORCE BASE, CALIF. - At Vandenberg Air Force Base, Calif., the Pegasus launch vehicle is moved toward its hangar. The Pegasus will carry the SciSat-1 spacecraft in a 400-mile-high polar orbit to investigate processes that control the distribution of ozone in the upper atmosphere. The data from the satellite will provide Canadian and international scientists with improved measurements relating to global ozone processes and help policymakers assess existing environmental policy and develop protective measures for improving the health of our atmosphere, preventing further ozone depletion. The mission is designed to last two years.

Effect of intrinsic magnetic field decrease on the low- to middle-latitude upper atmosphere dynamics simulated by GAIA

NASA Astrophysics Data System (ADS)

Tao, C.; Jin, H.; Shinagawa, H.; Fujiwara, H.; Miyoshi, Y.

2017-12-01

The effects of decreasing the intrinsic magnetic field on the upper atmospheric dynamics at low to middle latitudes are investigated using the Ground-to-topside model of Atmosphere and Ionosphere for Aeronomy (GAIA). GAIA incorporates a meteorological reanalysis data set at low altitudes (<30 km), which enables us to investigate the atmospheric response to various waves under dynamic and chemical interactions with the ionosphere. In this simulation experiment, we reduced the magnetic field strength to as low as 10% of the current value. The averaged neutral velocity, density, and temperature at low to middle latitudes at 300 km altitude show little change with the magnetic field variation, while the dynamo field, current density, and the ionospheric conductivities are modified significantly. The wind velocity and tidal wave amplitude in the thermosphere remain large owing to the small constraint on plasma motion for a small field. On the other hand, the superrotation feature at the dip equator is weakened by 20% for a 10% magnetic field because the increase in ion drag for the small magnetic field prevents the superrotation.

Effect of intrinsic magnetic field decrease on the low- to middle-latitude upper atmosphere dynamics simulated by GAIA

NASA Astrophysics Data System (ADS)

Tao, Chihiro; Jin, Hidekatsu; Shinagawa, Hiroyuki; Fujiwara, Hitoshi; Miyoshi, Yasunobu

2017-09-01

The effects of decreasing the intrinsic magnetic field on the upper atmospheric dynamics at low to middle latitudes are investigated using the Ground-to-topside model of Atmosphere and Ionosphere for Aeronomy (GAIA). GAIA incorporates a meteorological reanalysis data set at low altitudes (<30 km), which enables us to investigate the atmospheric response to various waves under dynamic and chemical interactions with the ionosphere. In this simulation experiment, we reduced the magnetic field strength to as low as 10% of the current value. The averaged neutral velocity, density, and temperature at low to middle latitudes at 300 km altitude show little change with the magnetic field variation, while the dynamo field, current density, and the ionospheric conductivities are modified significantly. The wind velocity and tidal wave amplitude in the thermosphere remain large owing to the small constraint on plasma motion for a small field. On the other hand, the superrotation feature at the dip equator is weakened by 20% for a 10% magnetic field because the increase in ion drag for the small magnetic field prevents the superrotation.

New measurements quantify atmospheric greenhouse effect

NASA Astrophysics Data System (ADS)

Bhattacharya, Atreyee

2012-10-01

In spite of a large body of existing measurements of incoming short-wave solar radiation and outgoing long-wave terrestrial radiation at the surface of the Earth and, more recently, in the upper atmosphere, there are few observations documenting how radiation profiles change through the atmosphere—information that is necessary to fully quantify the greenhouse effect of Earth's atmosphere. Through the use of existing technology but employing improvements in observational techniques it may now be possible not only to quantify but also to understand how different components of the atmosphere (e.g., concentration of gases, cloud cover, moisture, and aerosols) contribute to the greenhouse effect. Using weather balloons equipped with radiosondes, Philipona et al. continuously measured radiation fluxes from the surface of Earth up to altitudes of 35 kilometers in the upper stratosphere. Combining data from flights conducted during both day and night with continuous 24-hour measurements made at the surface of the Earth, the researchers created radiation profiles of all four components necessary to fully capture the radiation budget of Earth, namely, the upward and downward short-wave and long-wave radiation as a function of altitude.

Atmospheric water vapor: Distribution and Empirical estimation in the atmosphere of Thailand

NASA Astrophysics Data System (ADS)

Phokate, S.

2017-09-01

Atmospheric water vapor is a crucial component of the Earth’s atmosphere, which is shown by precipitable water vapor. It is calculated from the upper air data. In Thailand, the data were collected from four measuring stations located in Chiang Mai, Ubon Ratchathani, Bangkok, and Songkhla during the years 1998-2013. The precipitable water vapor obtained from this investigation were used to define an empirical model associated with the vapor pressure, which is a surface data at the same stations. The result shows that the relationship has a relatively high level of reliability. The precipitable water vapor obtained from the upper air data is nearly equal to the value from the model. The model was used to calculate the precipitable water vapor from the surface data 85 stations across the country. The result shows that seasonal change of the precipitable water vapor was low in the dry season (November-April) and high in the rainy season (May-October). In addition, precipitable water vapor varies along the latitudes of the stations. The high value obtains for low latitudes, but it is low for high latitudes.

Central role of carbonyl compounds in atmospheric chemistry

NASA Astrophysics Data System (ADS)

Lary, D. J.; Shallcross, D. E.

2000-08-01

With the exception of acetone it is not generally recognized how important atmospheric carbonyls and alkyl radicals are in the lower stratosphere and upper troposphere. Carbonyl compounds are the crucial intermediate species for the autocatalytic production of OH. For example, in the upper troposphere and lower stratosphere it is calculated based on data assimilation analysis of Atmospheric Trace Molecule Spectroscopy Experiment (ATMOS) data that CH3 production due to the degradation of carbonyls contributes around 40% to the overall production of CH3, a key initiation step for HOx production, with the contribution due to the photolysis of CH3CHO being comparable to that of acetone. So correctly modeling the alkyl radical concentrations is of central importance and has not be given the attention it deserves to date. The reactions of carbonyls with Br and Cl are also major sources of HBr and HCl. In short, carbonyl compounds play a central role in atmospheric chemistry close to the tropopause, and this is directly relevant to issues such as the assessment of the impact of air traffic, and ozone depletion.

Atmospheric helium and geomagnetic field reversals.

NASA Technical Reports Server (NTRS)

Sheldon, W. R.; Kern, J. W.

1972-01-01

The problem of the earth's helium budget is examined in the light of recent work on the interaction of the solar wind with nonmagnetic planets. It is proposed that the dominant mode of helium (He4) loss is ion pumping by the solar wind during geomagnetic field reversals, when the earth's magnetic field is very small. The interaction of the solar wind with the earth's upper atmosphere during such a period is found to involve the formation of a bow shock. The penetration altitude of the shock-heated solar plasma is calculated to be about 700 km, and ionization rates above this level are estimated for a cascade ionization (electron avalanche) process to average 10 to the 9th power ions/sq cm/sec. The calculated ionization rates and the capacity of the solar wind to remove ionized helium (He4) from the upper atmosphere during geomagnetic dipole reversals are sufficient to yield a secular equilibrium over geologic time scales. The upward transport of helium from the lower atmosphere under these conditions is found to be adequate to sustain the proposed loss rate.

Simulating Real-World Exposures during Emergency Events: Studying Effects of Indoor and Outdoor Releases in the Urban Dispersion Project in Upper Manhattan, NY

EPA Science Inventory

A prospective personal exposure study, involving indoor and outdoor releases, was conducted in upper Midtown Manhattan in New York City as part of the Urban Dispersion Program (UDP) focusing on atmospheric dispersion of chemicals in complex urban settings. The UDP experiments inv...

Agricultural injuries to the hand and upper extremity.

PubMed

Yaffe, Mark Aaron; Kaplan, F Thomas

2014-10-01

Agricultural injuries involving the hand and upper extremity are common, debilitating injuries that reflect the significant occupational hazards associated with the agricultural industry. Farm injuries occur in all age groups and are associated with significant resource utilization and treatment costs. Most of these injuries are associated with machinery, including tractors, power take-off devices, grain augers, hay balers, and combine harvesters. Each piece of machinery produces specific injury patterns and a spectrum of bone and soft-tissue injuries that are frequently characterized by the loss of a digit or limb, permanent disability, loss of function, and serious complications such as infection. Management of agricultural injuries includes expedient administration of antibiotic and tetanus prophylaxis, aggressive irrigation, serial débridement, consideration of delayed wound closure, and reconstruction or replantation of amputated digits and limbs, if feasible. Copyright 2014 by the American Academy of Orthopaedic Surgeons.

Muscle Strength Endurance Testing Development Based Photo Transistor with Motion Sensor Ultrasonic

NASA Astrophysics Data System (ADS)

Rusdiana, A.

2017-03-01

The endurance of upper-body muscles is one of the most important physical fitness components. As technology develops, the process of test and assessment is now getting digital; for instance, there are a sensor stuck to the shoe (Foot Pod, Polar, and Sunto), Global Positioning System (GPS) and Differential Global Positioning System (DGPS), radar, photo finish, kinematic analysis, and photocells. Those devices aim to analyze the performances and fitness of athletes particularly the endurance of arm, chest, and shoulder muscles. In relation to that, this study attempt to create a software and a hardware for pull-ups through phototransistor with ultrasonic motion sensor. Components needed to develop this device consist of microcontroller MCS-51, photo transistor, light emitting diode, buzzer, ultrasonic sensor, and infrared sensor. The infrared sensor is put under the buffer while the ultrasonic sensor is stuck on the upper pole. The components are integrated with an LED or a laptop made using Visual Basic 12 software. The results show that pull-ups test using digital device (mean; 9.4 rep) is lower than using manual calculation (mean; 11.3 rep). This is due to the fact that digital test requires the test-takers to do pull-ups perfectly.

The Mega Mesospheric Parachute

NASA Technical Reports Server (NTRS)

Kloesel, Kurt J.; Oberto, Robert; Kinsey, Robert

2005-01-01

The current understanding and modeling of the upper reaches of the atmosphere is incomplete. Upper atmospheric interactions with the lower atmosphere, effects of ionizing radiation, high altitude cloud phenomena, and the dynamical interaction with the magnetosphere require greater definition. The scientific objective of obtaining a greater understanding of the upper atmosphere can be achieved by designing, implementing, testing, and utilizing a facility that provides long period in-situ measurements of the mesosphere. Current direct sub-sonic measurements of the upper atmosphere are hampered by the approximately one minute sub-sonic observation window of a ballistic sounding rocket regardless of the launch angle. In-situ measurements at greater than transonic speeds impart energy into the molecular atmospheric system and distort the true atmospheric chemistry. A long duration, sub-sonic capability will significantly enhance our ability to observe and measure: (1) mesospheric lightning phenomena (sprites and blue jets) (2) composition, structure and stratification of noctilucent clouds (3) physics of seasonal radar echoes, gravity wave phenomena (4) chemistry of mesospheric gaseous ratio mixing (5) mesospheric interaction of ionizing radiation (6) dynamic electric and magnetic fields This new facility will also provide local field measurements which complement those that can be obtained through external measurements from satellite and ground-based platforms. The 400 foot (approximately 130 meter) diameter lightweight mega-mesospheric parachute system, deployed with a sounding rocket, is proposed herein as a method to increase sub-sonic mesospheric measurement time periods by more than an order of magnitude. The report outlines a multi-year evolving science instrumentation suite in parallel with the development of the mega meso-chute facility. The developmental issues surrounding the meso-chute are chiefly materials selection (thermal and structural) and deployment mechanism physics. Three mission cases were conceived and developed to include cost and schedules estimates. Each scenario has increasing scientific utility with paralleling launch weight, parachute hang-time, deployment altitude, and parachute size: (1) Case #1: $8.4M@24 months, 6kg payload, 20 min., 50km alt., 80 m. dia. (2) Case #2: $10.4M@24 months, 6kg payload, 20 min., 60km alt, 130m. dia. (3) Case #3: $13.6M@36 months, 30kg payload, 30 min., 90km alt., 200m. dia. The initial breakout cost for the parachute system is approximately $2M@24 months. This report identifies that although the challenges of the mega-meso-chute may be difficult, they can be surmounted and valuable results can be achieved.

Initial Examination of the Long Term Thermosphere Changes As Seen in the Whole Atmosphere Community Climate Model - eXtended (WACCM-X) J. M. McInerney, L. Qian, and H.-L Liu

NASA Astrophysics Data System (ADS)

McInerney, J. M.; Qian, L.; Liu, H.

2013-12-01

It has been over two decades since the projection that, not only will the human induced increase in atmospheric CO2 produce a warming in the troposphere, it will also produce a cooling in the middle to upper atmosphere into the 21st century with significant consequences. The thermospheric density decrease associated with this projected upper atmosphere cooling due to greenhouse gases has been confirmed by observations, in particular satellite drag measurements, and by various modeling studies. Recent studies also suggest potential impacts from the lower atmosphere on thermosphere dynamics such as atmospheric thermal tides and gravity waves. With the current advance of whole atmosphere climate models which extend from the ground through the thermosphere, it is now possible to include effects of these and other lower atmosphere processes in modeling studies of long term thermospheric changes. One such whole atmosphere model under development at the National Center for Atmospheric Research (NCAR) is the Whole Atmosphere Community Climate Model - eXtended (WACCM-X). WACCM-X is a self consistent climate model extending from the ground to approximately 500 kilometers and is based on the Whole Atmosphere Community Climate Model (WACCM) / Community Atmosphere Model (CAM) component of the Community Earth System Model (CESM). Although an interactive ionosphere module is not complete, the globally averaged structure of thermosphere temperature and neutral species from WACCM-X are reasonable compared with the NCAR global mean model. In this study, we will examine a transient WACCM-X simulation from 1955 to 2005 with realistic tropospheric CO2 input and solar and geomagnetic forcing. The preliminary study will focus on the long term changes in the thermosphere from this simulation, in particular the secular changes of thermosphere neutral density and temperature due to anthropogenic forcing.

XUV-Exposed, Non-Hydrostatic Hydrogen-Rich Upper Atmospheres of Terrestrial Planets. Part II: Hydrogen Coronae and Ion Escape

PubMed Central

Lammer, Helmut; Holmström, Mats; Panchenko, Mykhaylo; Odert, Petra; Erkaev, Nikolai V.; Leitzinger, Martin; Khodachenko, Maxim L.; Kulikov, Yuri N.; Güdel, Manuel; Hanslmeier, Arnold

2013-01-01

Abstract We studied the interactions between the stellar wind plasma flow of a typical M star, such as GJ 436, and the hydrogen-rich upper atmosphere of an Earth-like planet and a “super-Earth” with a radius of 2 REarth and a mass of 10 MEarth, located within the habitable zone at ∼0.24 AU. We investigated the formation of extended atomic hydrogen coronae under the influences of the stellar XUV flux (soft X-rays and EUV), stellar wind density and velocity, shape of a planetary obstacle (e.g., magnetosphere, ionopause), and the loss of planetary pickup ions on the evolution of hydrogen-dominated upper atmospheres. Stellar XUV fluxes that are 1, 10, 50, and 100 times higher compared to that of the present-day Sun were considered, and the formation of high-energy neutral hydrogen clouds around the planets due to the charge-exchange reaction under various stellar conditions was modeled. Charge-exchange between stellar wind protons with planetary hydrogen atoms, and photoionization, lead to the production of initially cold ions of planetary origin. We found that the ion production rates for the studied planets can vary over a wide range, from ∼1.0×1025 s−1 to ∼5.3×1030 s−1, depending on the stellar wind conditions and the assumed XUV exposure of the upper atmosphere. Our findings indicate that most likely the majority of these planetary ions are picked up by the stellar wind and lost from the planet. Finally, we estimated the long-time nonthermal ion pickup escape for the studied planets and compared them with the thermal escape. According to our estimates, nonthermal escape of picked-up ionized hydrogen atoms over a planet's lifetime within the habitable zone of an M dwarf varies between ∼0.4 Earth ocean equivalent amounts of hydrogen (EOH) to <3 EOH and usually is several times smaller in comparison to the thermal atmospheric escape rates. Key Words: Stellar activity—Low-mass stars—Early atmospheres—Earth-like exoplanets—Energetic neutral atoms—Ion escape—Habitability. Astrobiology 13, 1030–1048. PMID:24283926

XUV-exposed, non-hydrostatic hydrogen-rich upper atmospheres of terrestrial planets. Part II: hydrogen coronae and ion escape.

PubMed

Kislyakova, Kristina G; Lammer, Helmut; Holmström, Mats; Panchenko, Mykhaylo; Odert, Petra; Erkaev, Nikolai V; Leitzinger, Martin; Khodachenko, Maxim L; Kulikov, Yuri N; Güdel, Manuel; Hanslmeier, Arnold

2013-11-01

We studied the interactions between the stellar wind plasma flow of a typical M star, such as GJ 436, and the hydrogen-rich upper atmosphere of an Earth-like planet and a "super-Earth" with a radius of 2 R(Earth) and a mass of 10 M(Earth), located within the habitable zone at ∼0.24 AU. We investigated the formation of extended atomic hydrogen coronae under the influences of the stellar XUV flux (soft X-rays and EUV), stellar wind density and velocity, shape of a planetary obstacle (e.g., magnetosphere, ionopause), and the loss of planetary pickup ions on the evolution of hydrogen-dominated upper atmospheres. Stellar XUV fluxes that are 1, 10, 50, and 100 times higher compared to that of the present-day Sun were considered, and the formation of high-energy neutral hydrogen clouds around the planets due to the charge-exchange reaction under various stellar conditions was modeled. Charge-exchange between stellar wind protons with planetary hydrogen atoms, and photoionization, lead to the production of initially cold ions of planetary origin. We found that the ion production rates for the studied planets can vary over a wide range, from ∼1.0×10²⁵ s⁻¹ to ∼5.3×10³⁰ s⁻¹, depending on the stellar wind conditions and the assumed XUV exposure of the upper atmosphere. Our findings indicate that most likely the majority of these planetary ions are picked up by the stellar wind and lost from the planet. Finally, we estimated the long-time nonthermal ion pickup escape for the studied planets and compared them with the thermal escape. According to our estimates, nonthermal escape of picked-up ionized hydrogen atoms over a planet's lifetime within the habitable zone of an M dwarf varies between ∼0.4 Earth ocean equivalent amounts of hydrogen (EO(H)) to <3 EO(H) and usually is several times smaller in comparison to the thermal atmospheric escape rates.

Apparatus and method for the horizontal, crucible-free growth of silicon sheet crystals

DOEpatents

Ciszek, Theodore F.

1987-01-01

Apparatus for continuously forming a silicon crystal sheet from a silicon rod in a noncrucible environment. The rod is rotated and fed toward an RF coil in an inert atmosphere so that the upper end of the rod becomes molten and the silicon sheet crystal is pulled therefrom substantially horizontally in a continuous strip. A shorting ring may be provided around the rod to limit the heating to the upper end only. Argon gas can be used to create the inert atmosphere within a suitable closed chamber. By use of this apparatus and method, a substantially defect-free silicon crystal sheet is formed that can be used for microcircuitry chips or solar cells.

The use of the German V-2 in US for upper atmosphere research

NASA Technical Reports Server (NTRS)

Curtis, S. A.

1979-01-01

Early U.S. space experiments involving the liquid propellant German V-2 are discussed. Although the primary objective of the experiments conducted under project Hermes after World War II was initially the development of missile technology, scientific objectives were soon given the priority. The missile was modified for scientific experiments and the payload increased from 6.8% to 47% between 1946 and 1949. Among other instruments, the payload included a cosmic ray telescope, ionosphere transmitter and spectrograph for solar spectral measurements. While the scientific success of the program established a positive public attitude towards space research, the Upper Atmosphere Research Panel, formed to coordinate the project, set a pattern for future scientific advisory bodies.

Joint US Navy/US Air Force climatic study of the upper atmosphere. Volume 1: January

NASA Astrophysics Data System (ADS)

Changery, Michael J.; Williams, Claude N.; Dickenson, Michael L.; Wallace, Brian L.

1989-07-01

The upper atmosphere was studied based on 1980 to 1985 twice daily gridded analyses produced by the European Centre for Medium Range Weather Forecasts. This volume is for the month of January. Included are global analyses of: (1) Mean temperature standard deviation; (2) Mean geopotential height standard deviation; (3) Mean density standard deviation; (4) Mean density standard deviation (all for 13 levels - 1000, 850, 700, 500, 400, 300, 250, 200, 150, 100, 70, 50, 30 mb); (5) Mean dew point standard deviation for the 13 levels; and (6) Jet stream at levels 500 through 30 mb. Also included are global 5 degree grid point wind roses for the 13 pressure levels.

Temperature structure of the Uranian upper atmosphere

NASA Technical Reports Server (NTRS)

Elliot, J. L.; Dunham, E.

1979-01-01

The temperature structure of the upper atmosphere of Uranus at two locations on the planet was determined from observations of the occultation of the star SAO158687 by Uranus on 10 March 1977, carried out at the Kuiper Airborne Observatory. The temperature-pressure relationships obtained from the immersion and emersion data for 7280 A channel show peak-to-peak variations of 45 K for immersion and 35 K for emersion. The mean temperature for both immersion and emersion profiles is about 100 K, which shows that Uranus has a temperature inversion between 0.001 mbar and the 100 mbar level probed by IR measurements. Both profiles show wavelike temperature variations, which may be due to dynamical or photochemical processes.

Investigation of the external flow analysis for density measurements at high altitude. [shuttle upper atmosphere mass spectrometer experiment

NASA Technical Reports Server (NTRS)

Bienkowski, G. K.

1983-01-01

A Monte Carlo program was developed for modeling the flow field around the space shuttle in the vicinity of the shuttle upper atmosphere mass spectrometer experiment. The operation of the EXTERNAL code is summarized. Issues associated with geometric modeling of the shuttle nose region and the modeling of intermolecular collisions including rotational energy exchange are discussed as well as a preliminary analysis of vibrational excitation and dissociation effects. The selection of trial runs is described and the parameters used for them is justified. The original version and the modified INTERNAL code for the entrance problem are reviewed. The code listing is included.

Halogen occultation experiment intergrated test plan

NASA Technical Reports Server (NTRS)

Mauldin, L. E., III; Butterfield, A. J.

1986-01-01

The test program plan is presented for the Halogen Occultation Experiment (HALOE) instrument, which is being developed in-house at the Langley Research Center for the Upper Atmosphere Research Satellite (UARS). This comprehensive test program was developed to demonstrate that the HALOE instrument meets its performance requirements and maintains integrity through UARS flight environments. Each component, subsystem, and system level test is described in sufficient detail to allow development of the necessary test setups and test procedures. Additionally, the management system for implementing this test program is given. The HALOE instrument is a gas correlation radiometer that measures vertical distribution of eight upper atmospheric constituents: O3, HC1, HF, NO, CH4, H2O, NO2, and CO2.

Validation of Earth atmosphere models using solar EUV observations from the CORONAS and PROBA2 satellites in occultation mode

NASA Astrophysics Data System (ADS)

Slemzin, Vladimir; Ulyanov, Artyom; Gaikovich, Konstantin; Kuzin, Sergey; Pertsov, Andrey; Berghmans, David; Dominique, Marie

2016-02-01

Aims: Knowledge of properties of the Earth's upper atmosphere is important for predicting the lifetime of low-orbit spacecraft as well as for planning operation of space instruments whose data may be distorted by atmospheric effects. The accuracy of the models commonly used for simulating the structure of the atmosphere is limited by the scarcity of the observations they are based on, so improvement of these models requires validation under different atmospheric conditions. Measurements of the absorption of the solar extreme ultraviolet (EUV) radiation in the upper atmosphere below 500 km by instruments operating on low-Earth orbits (LEO) satellites provide efficient means for such validation as well as for continuous monitoring of the upper atmosphere and for studying its response to the solar and geomagnetic activity. Method: This paper presents results of measurements of the solar EUV radiation in the 17 nm wavelength band made with the SPIRIT and TESIS telescopes on board the CORONAS satellites and the SWAP telescope on board the PROBA2 satellite in the occulted parts of the satellite orbits. The transmittance profiles of the atmosphere at altitudes between 150 and 500 km were derived from different phases of solar activity during solar cycles 23 and 24 in the quiet state of the magnetosphere and during the development of a geomagnetic storm. We developed a mathematical procedure based on the Tikhonov regularization method for solution of ill-posed problems in order to retrieve extinction coefficients from the transmittance profiles. The transmittance profiles derived from the data and the retrieved extinction coefficients are compared with simulations carried out with the NRLMSISE-00 atmosphere model maintained by Naval Research Laboratory (USA) and the DTM-2013 model developed at CNES in the framework of the FP7 project ATMOP. Results: Under quiet and slightly disturbed magnetospheric conditions during high and low solar activity the extinction coefficients calculated by both models agreed with the measurements within the data errors. The NRLMSISE-00 model was not able to predict the enhancement of extinction above 300 km observed after 14 h from the beginning of a geomagnetic storm whereas the DTM-2013 model described this variation with good accuracy.

HATS (High Altitude Thermal Sounder): a passive sensor solution to 3D high-resolution mapping of upper atmosphere dynamics (Conference Presentation)

NASA Astrophysics Data System (ADS)

Gordley, Larry; Marshall, Benjamin T.; Lachance, Richard L.

2016-10-01

This presentation introduces a High Altitude Thermal Sensor (HATS) that has the potential to resolve the thermal structure of the upper atmosphere (cloud top to 100km) with both horizontal and vertical resolution of 5-7 km or better. This would allow the complete characterization of the wave structures that carry weather signature from the underlying atmosphere. Using a novel gas correlation technique, an extremely high-resolution spectral scan is accomplished by measuring a Doppler modulated signal as the atmospheric thermal scene passes through the HATS 2D FOV. This high spectral resolution, difficult to impossible to achieve with any other passive technique, enables the separation of radiation emanating at high altitudes from that emanating at low altitudes. A principal component analysis of these modulation signals then exposes the complete thermal structure of the upper atmosphere. We show that nadir sounding from low earth orbit, using various branches of CO2 emission in the 17 to 15 micron region, with sufficient spectral resolution and spectral measurement range, can distinguish thermal energy that peaks at various altitudes. By observing the up-welling atmospheric emission through a low pressure (Doppler broadened) gas cell, as the scene passes through our FOV, a modulation signal is created as the atmospheric emission lines are shifted through the spectral position of the gas cell absorption lines. The modulation signal is shown to be highly correlated to the emission coming from the spectral location of the gas cell lines relative to the atmospheric emission lines. This effectively produces a scan of the atmospheric emission with a Doppler line resolution. Similar to thermal sounding of the troposphere, a principal component analysis of the modulation signal can be used to produce an altitude resolved profile, given a reasonable a priori temperature profile. It is then shown that with the addition of a limb observation with one CO2 broadband channel (similar to methods employed with sensors like LIMS on Nimbus 7, HIRDLS on Aura, and SABER on TIMED), a limb temperature profile can be retrieved and used as the a priori profile, nearly eliminating uncertainty due to a priori inaccuracy. Feasibility studies and proposed instrument designs are presented. A tutorial for a similar technique proposed for measuring winds and temperature with limb observations can be found at http://www.gats-inc.com/future_missions.html