Servicing and Deployment of National Resources in Sun-Earth Libration Point Orbits
NASA Technical Reports Server (NTRS)
Folta, David C.; Beckman, Mark; Mar, Greg C.; Mesarch, Michael; Cooley, Steven; Leete, Steven J.
2002-01-01
Spacecraft travel between the Sun-Earth system, the Earth-Moon system, and beyond has received extensive attention recently. The existence of a connection between unstable regions enables mission designers to envision scenarios of multiple spacecraft traveling cheaply from system to system, rendezvousing, servicing, and refueling along the way. This paper presents examples of transfers between the Sun-Earth and Earth-Moon systems using a true ephemeris and perturbation model. It shows the (Delta)V costs associated with these transfers, including the costs to reach the staging region from the Earth. It explores both impulsive and low thrust transfer trajectories. Additionally, analysis that looks specifically at the use of nuclear power in libration point orbits and the issues associated with them such as inadvertent Earth return is addressed. Statistical analysis of Earth returns and the design of biased orbits to prevent any possible return are discussed. Lastly, the idea of rendezvous between spacecraft in libration point orbits using impulsive maneuvers is addressed.
Evidence of the non-extensive character of Earth's ambient noise.
NASA Astrophysics Data System (ADS)
Koutalonis, Ioannis; Vallianatos, Filippos
2017-04-01
Investigation of dynamical features of ambient seismic noise is one of the important scientific and practical research challenges. In the same time there isgrowing interest concerning an approach to study Earth Physics based on thescience of complex systems and non extensive statistical mechanics which is a generalization of Boltzmann-Gibbs statistical physics (Vallianatos et al., 2016).This seems to be a promising framework for studying complex systems exhibitingphenomena such as, long-range interactions, and memory effects. Inthis work we use non-extensive statistical mechanics and signal analysis methodsto explore the nature of ambient noise as measured in the stations of the HSNC in South Aegean (Chatzopoulos et al., 2016). In the present work we analyzed the de-trended increments time series of ambient seismic noise X(t), in time windows of 20 minutes to 10 seconds within "calm time zones" where the human-induced noise presents a minimum. Following the non extensive statistical physics approach, the probability distribution function of the increments of ambient noise is investigated. Analyzing the probability density function (PDF)p(X), normalized to zero mean and unit varianceresults that the fluctuations of Earth's ambient noise follows a q-Gaussian distribution asdefined in the frame of non-extensive statisticalmechanics indicated the possible existence of memory effects in Earth's ambient noise. References: F. Vallianatos, G. Papadakis, G. Michas, Generalized statistical mechanics approaches to earthquakes and tectonics. Proc. R. Soc. A, 472, 20160497, 2016. G. Chatzopoulos, I.Papadopoulos, F.Vallianatos, The Hellenic Seismological Network of Crete (HSNC): Validation and results of the 2013 aftershock,Advances in Geosciences, 41, 65-72, 2016.
Evidence of Non-extensivity in Earth's Ambient Noise
NASA Astrophysics Data System (ADS)
Koutalonis, Ioannis; Vallianatos, Filippos
2017-12-01
The study of ambient seismic noise is one of the important scientific and practical research challenges, due to its use in a number of geophysical applications. In this work, we describe Earth's ambient noise fluctuations in terms of non-extensive statistical physics. We found that Earth's ambient noise increments follow the q-Gaussian distribution. This indicates that Earth's ambient noise's fluctuations are not random and present long-term memory effects that could be described in terms of Tsallis entropy. Our results suggest that q values depend on the time length used and that the non-extensive parameter, q, converges to value q → 1 for short-time windows and a saturation value of q ≈ 1.33 for longer ones. The results are discussed from the point of view of superstatistics introduced by Beck [Contin Mech Thermodyn 16(3):293-304, 2004] and connects the q values with the system's degrees of freedom. Our work indicates that the converged (maximum) value is q = 1.33 and is related to 5 degrees of freedom.
NASA Technical Reports Server (NTRS)
Vollmer, Bruce E.; Ostrenga, D.; Savtchenko, A.; Johnson, J.; Wei, J.; Teng, W.; Gerasimov, I.
2011-01-01
NASA's Earth Science Program is dedicated to advancing Earth remote sensing and pioneering the scientific use of satellite measurements to improve human understanding of our home planet. Through the MEaSUREs Program, NASA is continuing its commitment to expand understanding of the Earth system using consistent data records. Emphasis is on linking together multiple data sources to form coherent time-series, and facilitating the use of extensive data in the development of comprehensive Earth system models. A primary focus of the MEaSUREs Program is the creation of Earth System Data Records (ESDRs). An ESDR is defined as a unified and coherent set of observations of a given parameter of the Earth system, which is optimized to meet specific requirements for addressing science questions. These records are critical for understanding Earth System processes; for the assessment of variability, long-term trends, and change in the Earth System; and for providing input and validation means to modeling efforts. Seven MEaSUREs projects will be archived and distributed through services at the Goddard Earth Sciences Data and Information Services Center (GES DISC).
Tamara Shapiro Ledley Receives 2013 Excellence in Geophysical Education Award: Citation
NASA Astrophysics Data System (ADS)
Reiff, Patricia
2014-01-01
It gives me great pleasure to cite Tamara Shapiro Ledley for the AGU Excellence in Geophysical Education Award "for her outstanding sustained leadership in Earth systems and climate change education." Tamara has shown an ongoing commitment to bridging the scientific and educational communities to make geophysical science knowledge and data accessible and usable to teachers and students and by extension to all citizens. She works extensively with both the scientific and educational communities. She began her educational work in 1990 as the leader for weather and climate in my Teacher Research program at Rice University. She continued as the lead for atmospheric sciences in our projects Earth Today and Museums Teaching Planet Earth, which introduced her to the Earth Science Information Partners (ESIP Federation). She has served many roles at ESIP, including creating the Standing Committee for Education and serving as vice president. ESIP recognized her many accomplishments with its President's Award in 2012. At TERC her education and outreach efforts have blossomed. She was the lead author of the "Earth as a System" investigation of the GLOBE Teacher's Guide. She was a member of the original Digital Library for Earth System Education (DLESE) Data Access Working Group in 2001, where the idea for a cookbook-like resource to facilitate the use of Earth science data by teachers and students resulted in her leading the development of the "Earth Exploration Toolbook" (EET), which allows teachers to easily access and use real scientific data in the classroom. Her efforts were recognized with the EET being awarded Science Magazine's Science Prize for Online Research in Education in 2011.
1993 Earth Observing System reference handbook
NASA Technical Reports Server (NTRS)
Asrar, Ghassem (Editor); Dokken, David Jon (Editor)
1993-01-01
Mission to Planet Earth (MTPE) is a NASA-sponsored concept that uses space- and ground-based measurement systems to provide the scientific basis for understanding global change. The space-based components of MTPE will provide a constellation of satellites to monitor the Earth from space. Sustained observations will allow researchers to monitor climate variables overtime to determine trends; however, space-based monitoring alone is not sufficient. A comprehensive data and information system, a community of scientists performing research with the data acquired, and extensive ground campaigns are all important components. Brief descriptions of the various elements that comprise the overall mission are provided. The Earth Observing System (EOS) - a series of polar-orbiting and low-inclination satellites for long-term global observations of the land surface, biosphere, solid Earth, atmosphere, and oceans - is the centerpiece of MTPE. The elements comprising the EOS mission are described in detail.
NASA Technical Reports Server (NTRS)
Casper, Paul W.; Bent, Rodney B.
1991-01-01
The algorithm used in previous technology time-of-arrival lightning mapping systems was based on the assumption that the earth is a perfect spheroid. These systems yield highly-accurate lightning locations, which is their major strength. However, extensive analysis of tower strike data has revealed occasionally significant (one to two kilometer) systematic offset errors which are not explained by the usual error sources. It was determined that these systematic errors reduce dramatically (in some cases) when the oblate shape of the earth is taken into account. The oblate spheroid correction algorithm and a case example is presented.
NASA Astrophysics Data System (ADS)
Pavlos, G. P.; Malandraki, O. E.; Pavlos, E. G.; Iliopoulos, A. C.; Karakatsanis, L. P.
2016-12-01
In this study we present some new and significant results concerning the dynamics of interplanetary coronal mass ejections (ICMEs) observed in the near Earth at L1 solar wind environment, as well as its effect in Earth's magnetosphere. The results are referred to Tsallis non-extensive statistics and in particular to the estimation of Tsallis q-triplet, (qstat ,qsen ,qrel) of magnetic field time series of the ICME observed at the Earth resulting from the solar eruptive activity on March 7, 2012 at the Sun. For this, we used a multi-spacecraft approach based on data experiments from ACE, CLUSTER 4, THEMIS-E and THEMIS-C spacecraft. For the data analysis different time periods were considered, sorted as ;quiet;, ;shock; and ;aftershock;, while different space domains such as the Interplanetary space (near Earth at L1 and upstream of the Earth's bowshock), the Earth's magnetosheath and magnetotail, were also taken into account. Our results reveal significant differences in statistical and dynamical features, indicating important variations of the magnetic field dynamics both in time and space domains during the shock event, in terms of rate of entropy production, relaxation dynamics and non-equilibrium meta-stable stationary states. So far, Tsallis non-extensive statistical theory and Tsallis extension of the Boltzmann-Gibbs entropy principle to the q-entropy principle (Tsallis, 1988, 2009) reveal strong universality character concerning non-equilibrium dynamics (Pavlos et al. 2012a,b, 2014a,b; Karakatsanis et al. 2013). Tsallis q-entropy principle can explain the emergence of a series of new and significant physical characteristics in distributed systems as well as in space plasmas. Such characteristics are: non-Gaussian statistics and anomalous diffusion processes, strange and fractional dynamics, multifractal, percolating and intermittent turbulence structures, multiscale and long spatio-temporal correlations, fractional acceleration and Non-Equilibrium Stationary States (NESS) or non-equilibrium self-organization process and non-equilibrium phase transition and topological phase transition processes according to Zelenyi and Milovanov (2004). In this direction, our results reveal clearly strong self-organization and development of macroscopic ordering of plasma system related to strengthen of non-extensivity, multifractality and intermittency everywhere in the space plasmas region during the CME event.
Spreading vs. Rifting as modes of extensional tectonics on the globally expanded Ganymede
NASA Astrophysics Data System (ADS)
Pizzi, Alberto; Domenica, Alessandra Di; Komatsu, Goro; Cofano, Alessandra; Mitri, Giuseppe; Bruzzone, Lorenzo
2017-05-01
The formation of Ganymede's sulci is likely related to extensional tectonics that affected this largest icy satellite of Jupiter. Through geometric and structural analyses we reconstructed the pre-deformed terrains and we recognized two different modes of extension associated with sulci. In the first mode, smooth sulci constitute spreading centers between two dark terrain plates, similar to the fast oceanic spreading centers on Earth. Here extension is primarily accommodated by crustal accretion of newly formed icy crust. In the second mode, dark terrain extension is mainly accommodated by swaths of normal fault systems analogous to Earth's continental crustal rifts. A comparison with terrestrial extensional analogues, based on the fault displacement/length (Dmax/L) ratio, spacing and morphology, showed that magmato-tectonic spreading centers and continental crustal rifts on Earth follow the same relative patterns observed on Ganymede. Our results suggest that the amount of extensional strain may have previously been underestimated since the occurrence of spreading centers may have played a major role in the tectonic evolution of the globally expanded Ganymede. We also discuss a possible model for the origin of the different modes of extension in the context of the global expansion of the satellite.
Citizen Science as a Tool for Scientific Research and Societal Benefit at NASA
NASA Technical Reports Server (NTRS)
Kaminski, Amy
2018-01-01
NASA's strategic goals include advancing knowledge and opportunity in space and improving life on Earth. We support these goals through extensive programs in space and Earth science research accomplished via space-based missions and research funding. NASA's "system" is configured to conduct science using (1) in-house personnel and (2) grants, contracts, and agreements with external entities (academia, industry, international space agencies.
Optical data communication for Earth observation satellite systems
NASA Astrophysics Data System (ADS)
Fischer, J.; Loecherbach, E.
1991-10-01
The current development status of optical communication engineering in comparison to the conventional microwave systems and the different configurations of the optical data communication for Earth observation satellite systems are described. An outlook to future optical communication satellite systems is given. During the last decade Earth observation became more and more important for the extension of the knowledge about our planet and the human influence on nature. Today pictures taken by satellites are used, for example, to discover mineral resources or to predict harvest, crops, climate, and environment variations and their influence on the population. A new and up to date application for Earth observation satellites can be the verification of disarmament arrangements and the control of crises areas. To solve these tasks a system of Earth observing satellites with sensors tailored to the envisaged mission is necessary. Besides these low Earth orbiting satellites, a global Earth observation system consists of at least two data relay satellites. The communication between the satellites will be established via Inter-Satellite Links (ISL) and Inter-Orbit Links (IOL). On these links, bitrates up to 1 Gbit/s must be taken into account. Due to the increasing scarcity of suitable frequencies, higher carrier frequencies must probably be considered, and possible interference with terrestrial radio relay systems are two main problems for a realization in microwave technique. One important step to tackle these problems is the use of optical frequencies for IOL's and ISL's.
Network Performance Measurements for NASA's Earth Observation System
NASA Technical Reports Server (NTRS)
Loiacono, Joe; Gormain, Andy; Smith, Jeff
2004-01-01
NASA's Earth Observation System (EOS) Project studies all aspects of planet Earth from space, including climate change, and ocean, ice, land, and vegetation characteristics. It consists of about 20 satellite missions over a period of about a decade. Extensive collaboration is used, both with other US. agencies (e.g., National Oceanic and Atmospheric Administration (NOA), United States Geological Survey (USGS), Department of Defense (DoD), and international agencies (e.g., European Space Agency (ESA), Japan Aerospace Exploration Agency (JAXA)), to improve cost effectiveness and obtain otherwise unavailable data. Scientific researchers are located at research institutions worldwide, primarily government research facilities and research universities. The EOS project makes extensive use of networks to support data acquisition, data production, and data distribution. Many of these functions impose requirements on the networks, including throughput and availability. In order to verify that these requirements are being met, and be pro-active in recognizing problems, NASA conducts on-going performance measurements. The purpose of this paper is to examine techniques used by NASA to measure the performance of the networks used by EOSDIS (EOS Data and Information System) and to indicate how this performance information is used.
ERBE and CERES broadband scanning radiometers
NASA Technical Reports Server (NTRS)
Weaver, William L.; Cooper, John E.
1990-01-01
Broadband scanning radiometers have been used extensively on earth-orbiting satellites to measure the Earth's outgoing radiation. The resulting estimates of longwave and shortwave fluxes have played an important role in helping to understand the Earth's radiant energy balance or budget. The Clouds and the Earth Radiant Energy System (CERES) experiment is expected to include instruments with three broadband scanning radiometers. The design of the CERES instrument will draw heavily from the flight-proven Earth Radiation Budget Experiment (ERBE) scanner instrument technology and will benefit from the several years of ERBE experience in mission operations and data processing. The discussion starts with a description of the scientific objectives of ERBE and CERES. The design and operational characteristics of the ERBE and CERES instrument are compared and the two ground-based data processing systems are compared. Finally, aspects of the CERES data processing which might be performed in near real-time aboard a spacecraft platform are discussed, and the types of algorithms and input data requirements for the onboard processing system are identified.
NASA Technical Reports Server (NTRS)
Vachon, Jacques; Curry, Robert E.
2010-01-01
Program Objectives: 1) Satellite Calibration and Validation: Provide methods to perform the cal/val requirements for Earth Observing System satellites. 2) New Sensor Development: Provide methods to reduce risk for new sensor concepts and algorithm development prior to committing sensors to operations. 3) Process Studies: Facilitate the acquisition of high spatial/temporal resolution focused measurements that are required to understand small atmospheric and surface structures which generate powerful Earth system effects. 4) Airborne Networking: Develop disruption-tolerant networking to enable integrated multiple scale measurements of critical environmental features. Dryden Capabilities include: a) Aeronautics history of aircraft developments and milestones. b) Extensive history and experience in instrument integration. c) Extensive history and experience in aircraft modifications. d) Strong background in international deployments. e) Long history of reliable and dependable execution of projects. f) Varied aircraft types providing different capabilities, performance and duration.
The Role and Evolution of NASA's Earth Science Data Systems
NASA Technical Reports Server (NTRS)
Ramapriyan, H. K.
2015-01-01
One of the three strategic goals of NASA is to Advance understanding of Earth and develop technologies to improve the quality of life on our home planet (NASA strategic plan 2014). NASA's Earth Science Data System (ESDS) Program directly supports this goal. NASA has been launching satellites for civilian Earth observations for over 40 years, and collecting data from various types of instruments. Especially since 1990, with the start of the Earth Observing System (EOS) Program, which was a part of the Mission to Planet Earth, the observations have been significantly more extensive in their volumes, variety and velocity. Frequent, global observations are made in support of Earth system science. An open data policy has been in effect since 1990, with no period of exclusive access and non-discriminatory access to data, free of charge. NASA currently holds nearly 10 petabytes of Earth science data including satellite, air-borne, and ground-based measurements and derived geophysical parameter products in digital form. Millions of users around the world are using NASA data for Earth science research and applications. In 2014, over a billion data files were downloaded by users from NASAs EOS Data and Information System (EOSDIS), a system with 12 Distributed Active Archive Centers (DAACs) across the U. S. As a core component of the ESDS Program, EOSDIS has been operating since 1994, and has been evolving continuously with advances in information technology. The ESDS Program influences as well as benefits from advances in Earth Science Informatics. The presentation will provide an overview of the role and evolution of NASAs ESDS Program.
A Down-to-Earth Educational Operating System for Up-in-the-Cloud Many-Core Architectures
ERIC Educational Resources Information Center
Ziwisky, Michael; Persohn, Kyle; Brylow, Dennis
2013-01-01
We present "Xipx," the first port of a major educational operating system to a processor in the emerging class of many-core architectures. Through extensions to the proven Embedded Xinu operating system, Xipx gives students hands-on experience with system programming in a distributed message-passing environment. We expose the software primitives…
NASA Astrophysics Data System (ADS)
Pavlos, George; Malandraki, Olga; Pavlos, Evgenios; Iliopoulos, Aggelos; Karakatsanis, Leonidas
2017-04-01
As the solar plasma lives far from equilibrium it is an excellent laboratory for testing non-equilibrium statistical mechanics. In this study, we present the highlights of Tsallis non-extensive statistical mechanics as concerns their applications at solar plasma dynamics, especially at solar wind phenomena and magnetosphere. In this study we present some new and significant results concerning the dynamics of interplanetary coronal mass ejections (ICMEs) observed in the near Earth at L1 solar wind environment, as well as its effect in Earth's magnetosphere. The results are referred to Tsallis non-extensive statistics and in particular to the estimation of Tsallis q-triplet, (qstat, qsen, qrel) of SEPs time series observed at the interplanetary space and magnetic field time series of the ICME observed at the Earth resulting from the solar eruptive activity on March 7, 2012 at the Sun. For the magnetic field, we used a multi-spacecraft approach based on data experiments from ACE, CLUSTER 4, THEMIS-E and THEMIS-C spacecraft. For the data analysis different time periods were considered, sorted as "quiet", "shock" and "aftershock", while different space domains such as the Interplanetary space (near Earth at L1 and upstream of the Earth's bowshock), the Earth's magnetosheath and magnetotail, were also taken into account. Our results reveal significant differences in statistical and dynamical features, indicating important variations of the SEPs profile in time, and magnetic field dynamics both in time and space domains during the shock event, in terms of rate of entropy production, relaxation dynamics and non-equilibrium meta-stable stationary states. So far, Tsallis non-extensive statistical theory and Tsallis extension of the Boltzmann-Gibbs entropy principle to the q-entropy entropy principle (Tsallis, 1988, 2009) reveal strong universality character concerning non-equilibrium dynamics (Pavlos et al. 2012a,b, 2014, 2015, 2016; Karakatsanis et al. 2013). Tsallis q-entropy principle can explain the emergence of a series of new and significant physical characteristics in distributed systems as well as in space plasmas. Such characteristics are: non-Gaussian statistics and anomalous diffusion processes, strange and fractional dynamics, multifractal, percolating and intermittent turbulence structures, multiscale and long spatio-temporal correlations, fractional acceleration and Non-Equilibrium Stationary States (NESS) or non-equilibrium self-organization process and non-equilibrium phase transition and topological phase transition processes according to Zelenyi and Milovanov (2004). In this direction, our results reveal clearly strong self-organization and development of macroscopic ordering of plasma system related to strengthen of non-extensivity, multifractality and intermittency everywhere in the space plasmas region during the CME event. Acknowledgements: This project has received funding form the European Union's Horizon 2020 research and innovation program under grant agreement No 637324.
Smouldering Fires in the Earth System
NASA Astrophysics Data System (ADS)
Rein, G.
2012-04-01
Smouldering fires, the slow, low-temperature, flameless burning, represent the most persistent type of combustion phenomena and the longest continuously fires on Earth system. Indeed, smouldering mega-fires of peatlands occur with some frequency during the dry session in, for example, Indonesia, Canada, Russia, UK and USA. Smouldering fires propagate slowly through organic layers of the ground and can reach depth >5 m if large cracks, natural piping or channel systems exist. It threatens to release sequestered carbon deep into the soil. Once ignited, they are particularly difficult to extinguish despite extensive rains, weather changes or fire-fighting attempts, and can persist for long periods of time (months, years) spreading deep and over extensive areas. Recent figures at the global scale estimate that average annual greenhouse gas emissions from smouldering fires are equivalent to 15% of man-made emissions. These fires are difficult or impossible to detect with current remote sensing methods because the chemistry is significantly different, their thermal radiation signature is much smaller, and the plume is much less buoyant. These wildfires burn fossil fuels and thus are a carbon-positive fire phenomena. This creates feedbacks in the climate system because soil moisture deficit and self-heating are enchanted under warmer climate scenarios and lead to more frequent fires. Warmer temperatures at high latitudes are resulting in more frequent Artic fires. Unprecedented permafrost thaw is leaving large soil carbon pools exposed to smouldering fires for the fist time since millennia. Although interactions between flaming fires and the Earth system have been a central focus, smouldering fires are as important but have received very little attention. DBut differences with flaming fires are important. This paper reviews the current knowledge on smouldering fires in the Earth system regarding combustion dynamics, damage to the soil, emissions, remote sensing and feedbacks in the climate system.
NASA Technical Reports Server (NTRS)
2004-01-01
Since its founding in 1992, Global Science & Technology, Inc. (GST), of Greenbelt, Maryland, has been developing technologies and providing services in support of NASA scientific research. GST specialties include scientific analysis, science data and information systems, data visualization, communications, networking and Web technologies, computer science, and software system engineering. As a longtime contractor to Goddard Space Flight Center s Earth Science Directorate, GST scientific, engineering, and information technology staff have extensive qualifications with the synthesis of satellite, in situ, and Earth science data for weather- and climate-related projects. GST s experience in this arena is end-to-end, from building satellite ground receiving systems and science data systems, to product generation and research and analysis.
Young Earth System Scientists (YESS) Community
NASA Astrophysics Data System (ADS)
Reed, K. A.; Langendijk, G.; Bahar, F.; Huang-Lachmann, J. T.; Osman, M.; Mirsafa, M.; Sonntag, S.
2017-12-01
The Young Earth System Scientists (YESS) community is compiled of early career researchers (including students) coming from a range of scientific backgrounds, spanning both natural and social sciences. YESS unifies young researchers in an influential network to give them a collective voice and leverage within the geosciences community, while supporting career development. The YESS community has used its powerful network to provide a unified perspective on the future of Earth system science (Rauser et al. 2017), to be involved in the organization of international conferences, and to engage with existing international structures that coordinate science. Since its founding in Germany in 2010, the YESS community has grown extensively across the globe, with currently almost 1000 members from over 80 countries, and has become truly interdisciplinary. Recently, the organization has carried elections for Regional Representatives and the Executive Committee as part of its self-sustained governance structure. YESS is ready to continue pioneering crucial areas of research which provide solutions to benefit society for the long-term advancement of Earth system science.
The Earth System Documentation (ES-DOC) Software Process
NASA Astrophysics Data System (ADS)
Greenslade, M. A.; Murphy, S.; Treshansky, A.; DeLuca, C.; Guilyardi, E.; Denvil, S.
2013-12-01
Earth System Documentation (ES-DOC) is an international project supplying high-quality tools & services in support of earth system documentation creation, analysis and dissemination. It is nurturing a sustainable standards based documentation eco-system that aims to become an integral part of the next generation of exa-scale dataset archives. ES-DOC leverages open source software, and applies a software development methodology that places end-user narratives at the heart of all it does. ES-DOC has initially focused upon nurturing the Earth System Model (ESM) documentation eco-system and currently supporting the following projects: * Coupled Model Inter-comparison Project Phase 5 (CMIP5); * Dynamical Core Model Inter-comparison Project (DCMIP); * National Climate Predictions and Projections Platforms Quantitative Evaluation of Downscaling Workshop. This talk will demonstrate that ES-DOC implements a relatively mature software development process. Taking a pragmatic Agile process as inspiration, ES-DOC: * Iteratively develops and releases working software; * Captures user requirements via a narrative based approach; * Uses online collaboration tools (e.g. Earth System CoG) to manage progress; * Prototypes applications to validate their feasibility; * Leverages meta-programming techniques where appropriate; * Automates testing whenever sensibly feasible; * Streamlines complex deployments to a single command; * Extensively leverages GitHub and Pivotal Tracker; * Enforces strict separation of the UI from underlying API's; * Conducts code reviews.
Tether Transportation System Study
NASA Technical Reports Server (NTRS)
Bangham, M. E.; Lorenzini, E.; Vestal, L.
1998-01-01
The projected traffic to geostationary earth orbit (GEO) is expected to increase over the next few decades. At the same time, the cost of delivering payloads from the Earth's surface to low earth orbit (LEO) is projected to decrease, thanks in part to the Reusable Launch Vehicle (RLV). A comparable reduction in the cost of delivering payloads from LEO to GEO is sought. The use of in-space tethers, eliminating the requirement for traditional chemical upper stages and thereby reducing the launch mass, has been identified as such an alternative. Spinning tethers are excellent kinetic energy storage devices for providing the large delta vee's required for LEO to GEO transfer. A single-stage system for transferring payloads from LEO to GEO was proposed some years ago. The study results presented here contain the first detailed analyses of this proposal, its extension to a two-stage system, and the likely implementation of the operational system.
Development of a model to compute the extension of life supporting zones for Earth-like exoplanets.
Neubauer, David; Vrtala, Aron; Leitner, Johannes J; Firneis, Maria G; Hitzenberger, Regina
2011-12-01
A radiative convective model to calculate the width and the location of the life supporting zone (LSZ) for different, alternative solvents (i.e. other than water) is presented. This model can be applied to the atmospheres of the terrestrial planets in the solar system as well as (hypothetical, Earth-like) terrestrial exoplanets. Cloud droplet formation and growth are investigated using a cloud parcel model. Clouds can be incorporated into the radiative transfer calculations. Test runs for Earth, Mars and Titan show a good agreement of model results with observations.
Supporting EarthScope Cyber-Infrastructure with a Modern GPS Science Data System
NASA Astrophysics Data System (ADS)
Webb, F. H.; Bock, Y.; Kedar, S.; Jamason, P.; Fang, P.; Dong, D.; Owen, S. E.; Prawirodirjo, L.; Squibb, M.
2008-12-01
Building on NASA's investment in the measurement of crustal deformation from continuous GPS, we are developing and implementing a Science Data System (SDS) that will provide mature, long-term Earth Science Data Records (ESDR's). This effort supports NASA's Earth Surface and Interiors (ESI) focus area and provide NASA's component to the EarthScope PBO. This multi-year development is sponsored by NASA's Making Earth System data records for Use in Research Environments (MEaSUREs) program. The SDS integrates the generation of ESDRs with data analysis and exploration, product generation, and modeling tools based on daily GPS data that include GPS networks in western North America and a component of NASA's Global GPS Network (GGN) for terrestrial reference frame definition. The system is expandable to multiple regional and global networks. The SDS builds upon mature data production, exploration, and analysis algorithms developed under NASA's REASoN, ACCESS, and SENH programs. This SDS provides access to positions, time series, velocity fields, and strain measurements derived from continuous GPS data obtained at tracking stations in both the Plate Boundary Observatory and other regional Western North America GPS networks, dating back to 1995. The SDS leverages the IT and Web Services developments carried out under the SCIGN/REASoN and ACCESS projects, which have streamlined access to data products for researchers and modelers, and which have created a prototype an on-the-fly interactive research environment through a modern data portal, GPS Explorer. This IT system has been designed using modern IT tools and principles in order to be extensible to any geographic location, scale, natural hazard, and combination of geophysical sensor and related data. We have built upon open GIS standards, particularly those of the OGC, and have used the principles of Web Service-based Service Oriented Architectures to provide scalability and extensibility to new services and capabilities.
NASA Technical Reports Server (NTRS)
Putman, William M.
2010-01-01
The Goddard Earth Observing System Model (GEOS-S), an earth system model developed in the NASA Global Modeling and Assimilation Office (GMAO), has integrated the non-hydrostatic finite-volume dynamical core on the cubed-sphere grid. The extension to a non-hydrostatic dynamical framework and the quasi-uniform cubed-sphere geometry permits the efficient exploration of global weather and climate modeling at cloud permitting resolutions of 10- to 4-km on today's high performance computing platforms. We have explored a series of incremental increases in global resolution with GEOS-S from irs standard 72-level 27-km resolution (approx.5.5 million cells covering the globe from the surface to 0.1 hPa) down to 3.5-km (approx. 3.6 billion cells).
DOE Office of Scientific and Technical Information (OSTI.GOV)
Jones, Andew; Di Vittorio, Alan; Collins, William
The integrated Earth system model (iESM) has been developed as a new tool for projecting the joint human/climate system. The iESM is based upon coupling an integrated assessment model (IAM) and an Earth system model (ESM) into a common modeling infrastructure. IAMs are the primary tool for describing the human-Earth system, including the sources of global greenhouse gases (GHGs) and short-lived species (SLS), land use and land cover change (LULCC), and other resource-related drivers of anthropogenic climate change. ESMs are the primary scientific tools for examining the physical, chemical, and biogeochemical impacts of human-induced changes to the climate system. Themore » iESM project integrates the economic and human-dimension modeling of an IAM and a fully coupled ESM within a single simulation system while maintaining the separability of each model if needed. Both IAM and ESM codes are developed and used by large communities and have been extensively applied in recent national and international climate assessments. By introducing heretofore-omitted feedbacks between natural and societal drivers, we can improve scientific understanding of the human-Earth system dynamics. Potential applications include studies of the interactions and feedbacks leading to the timing, scale, and geographic distribution of emissions trajectories and other human influences, corresponding climate effects, and the subsequent impacts of a changing climate on human and natural systems.« less
Ground System Extensibility Considerations
NASA Astrophysics Data System (ADS)
Miller, S. W.; Greene, E.
2017-12-01
The National Oceanic and Atmospheric Administration (NOAA) and National Aeronautics and Space Administration (NASA) are jointly acquiring the next-generation civilian weather and environmental satellite system: the Joint Polar Satellite System (JPSS). The Joint Polar Satellite System will replace the afternoon orbit component and ground processing system of the current Polar-orbiting Operational Environmental Satellites (POES) managed by NOAA. The JPSS satellites will carry a suite of sensors designed to collect meteorological, oceanographic, climatological and geophysical observations of the Earth. The ground processing system for JPSS is known as the JPSS Common Ground System (JPSS CGS). Developed and maintained by Raytheon Intelligence, Information and Services (IIS), the CGS is a multi-mission enterprise system serving NOAA, NASA and their national and international partners, such as NASA's Earth Observation System (EOS), NOAA's current POES, the Japan Aerospace Exploration Agency's (JAXA) Global Change Observation Mission - Water (GCOM-W1), and DoD's Defense Meteorological Satellite Program (DMSP). The CGS provides a wide range of support to a number of national and international missions, including command and control, mission management, data acquisition and routing, and environmental data processing and distribution. The current suite of CGS-supported missions has demonstrated the value of interagency and international partnerships to address global observation needs. With its established infrastructure and existing suite of missions, the CGS is extensible to a wider array of potential new missions. This paper will describe how the inherent scalability and extensibility of the CGS enables the addition of these new missions, with an eye on global enterprise needs in the 2020's and beyond.
NASA Astrophysics Data System (ADS)
Alameh, N.; Bambacus, M.; Cole, M.
2006-12-01
Nasa's Earth Science as well as interdisciplinary research and applications activities require access to earth observations, analytical models and specialized tools and services, from diverse distributed sources. Interoperability and open standards for geospatial data access and processing greatly facilitate such access among the information and processing compo¬nents related to space¬craft, airborne, and in situ sensors; predictive models; and decision support tools. To support this mission, NASA's Geosciences Interoperability Office (GIO) has been developing the Earth Science Gateway (ESG; online at http://esg.gsfc.nasa.gov) by adapting and deploying a standards-based commercial product. Thanks to extensive use of open standards, ESG can tap into a wide array of online data services, serve a variety of audiences and purposes, and adapt to technology and business changes. Most importantly, the use of open standards allow ESG to function as a platform within a larger context of distributed geoscience processing, such as the Global Earth Observing System of Systems (GEOSS). ESG shares the goals of GEOSS to ensure that observations and products shared by users will be accessible, comparable, and understandable by relying on common standards and adaptation to user needs. By maximizing interoperability, modularity, extensibility and scalability, ESG's architecture fully supports the stated goals of GEOSS. As such, ESG's role extends beyond that of a gateway to NASA science data to become a shared platform that can be leveraged by GEOSS via: A modular and extensible architecture Consensus and community-based standards (e.g. ISO and OGC standards) A variety of clients and visualization techniques, including WorldWind and Google Earth A variety of services (including catalogs) with standard interfaces Data integration and interoperability Mechanisms for user involvement and collaboration Mechanisms for supporting interdisciplinary and domain-specific applications ESG has played a key role in recent GEOSS Service Network (GSN) demos and workshops, acting not only as a service and data catalog and discovery client, but also as a portrayal and visualization client to distributed data.
A Reusable Design for Precision Lunar Landing Systems
NASA Technical Reports Server (NTRS)
Fuhrman, Linda; Brand, Timothy; Fill, Tom; Norris, Lee; Paschall, Steve
2005-01-01
The top-level architecture to accomplish NASA's Vision for Space Exploration is to use Lunar missions and systems not just as an end in themselves, but also as testbeds for the more ambitious goals of Human Mars Exploration (HME). This approach means that Lunar missions and systems are most likely going to be targeted for (Lunar) polar missions, and also for long-duration (months) surface stays. This overacting theme creates basic top-level requirements for any next-generation lander system: 1) Long duration stays: a) Multiple landers in close proximity; b) Pinpoint landings for "surface rendezvous"; c) Autonomous landing of pre-positioned assets; and d) Autonomous Hazard Detection and Avoidance. 2) Polar and deep-crater landings (dark); 3) Common/extensible systems for Moon and Mars, crew and cargo. These requirements pose challenging technology and capability needs. Compare and contrast: 4) Apollo: a) 1 km landing accuracy; b) Lunar near-side (well imaged and direct-to-Earth com. possible); c) Lunar equatorial (landing trajectories offer best navigation support from Earth); d) Limited lighting conditions; e) Significant ground-in-the-loop operations; 5) Lunar Access: a) 10-100m landing precision; b) "Anywhere" access includes polar (potentially poor nav. support from Earth) and far side (poor gravity and imaging; no direct-to-Earth com); c) "Anytime" access includes any lighting condition (including dark); d) Full autonomous landing capability; e) Extensible design for tele-operation or operator-in-the-loop; and f) Minimal ground support to reduce operations costs. The Lunar Access program objectives, therefore, are to: a) Develop a baseline Lunar Precision Landing System (PLS) design to enable pinpoint "anywhere, anytime" landings; b) landing precision 10m-100m; c) Any LAT, LON; and d) Any lighting condition; This paper will characterize basic features of the next generation Lunar landing system, including trajectory types, sensor suite options and a reference system architecture.
The value of earth observations: methods and findings on the value of Landsat imagery
Miller, Holly M.; Serbina, Larisa O.; Richardson, Leslie A.; Ryker, Sarah J.; Newman, Timothy R.
2016-01-01
Data from Earth observation systems are used extensively in managing and monitoring natural resources, natural hazards, and the impacts of climate change, but the value of such data can be difficult to estimate, particularly when it is available at no cost. Assessing the socioeconomic and scientific value of these data provides a better understanding of the existing and emerging research, science, and applications related to this information and contributes to the decision making process regarding current and future Earth observation systems. Recent USGS research on Landsat data has advanced the literature in this area by using a variety of methods to estimate value. The results of a 2012 survey of Landsat users, a 2013 requirements assessment, and 2013 case studies of applications of Landsat imagery are discussed.
Different orders of lives in the universe
NASA Astrophysics Data System (ADS)
Sikdar, M. K.
2014-08-01
In this article, main life sensitive elements involved in life creating processes on earth have been explored. An in-depth study has been made to search out material abundances of all life sensitive elements in the periodic table mainly on earth, celestial bodies like star, binary stars, extra-solar system, extra solar planets and galaxies etc. at large. Extensive review has been made to project how life processes are being triggered in our earth and intakes required for continuous metabolism, mutation, reproducibility etc. Finally on the basis of ideas developed about the life processes on earth, other life chains that may happen to exist on other celestial bodies have been predicted. The constraints and barriers that stand in the way of communications have also been pointed out.
STS-42 Earth observation of New York City (NYC), New York
1992-01-30
STS-42 Earth observation taken aboard Discovery, Orbiter Vehicle (OV) 103, is of New York City (NYC), New York (41.0N, 74.0W). Snow cover highlights the large areas of development and the many reservoirs in this wintertime scene of the metropolitan NYC area. Features such as Central Park in Manhattan, the George Washington Bridge connecting Manhattan with New Jersey, street patterns in most of the boroughs, La Guardia and JFK airports in Queens, and the extensive harbor system are easily identified.
STS-42 Earth observation of New York City (NYC), New York
NASA Technical Reports Server (NTRS)
1992-01-01
STS-42 Earth observation taken aboard Discovery, Orbiter Vehicle (OV) 103, is of New York City (NYC), New York (41.0N, 74.0W). Snow cover highlights the large areas of development and the many reservoirs in this wintertime scene of the metropolitan NYC area. Features such as Central Park in Manhattan, the George Washington Bridge connecting Manhattan with New Jersey, street patterns in most of the boroughs, La Guardia and JFK airports in Queens, and the extensive harbor system are easily identified.
2011-10-01
enable more extensive cost-capped, Discovery class NASA missions such as robotic missions to Mars and near- Earth asteroids to perform round trip sample...could be facilitated with higher performance propulsion systems include robotic missions to the Moon, Mars, and near- Earth asteroids to perform round...discharge in the case with nitrogen gas mixing. This is not due to the common misconception that molecular gases would have a higher ionization energy
1984-07-01
Faurie U of Illinois 312-996-2141 A.D. Morrison Jet Propulsion Lab 213-354- 7200 A.R. Calawa Lincoln Lab, MIT 617-863-550C Ron Kerber DARPA 202-694...environment can only be assessed following extensive experimentation in space.2 mM Considering the failure of all efforts to suppress, during growth on earth ... earth because of constitutional supercooling effect. For oxide systems, the possibility exists to establish non-wetting configurations and thus to avoid
Incorporating Geoethics in Introductory Earth System Science Courses
NASA Astrophysics Data System (ADS)
Schmitt, J.
2014-12-01
The integrative nature of Earth System Science courses provides extensive opportunities to introduce students to geoethical inquiry focused on globally significant societal issues. Geoscience education has traditionally lagged in its efforts to increase student awareness of the significance of geologic knowledge to understanding and responsibly confronting causes and possible solutions for emergent, newly emerging, and future problems of anthropogenic cause and consequence. Developing an understanding of the human impact on the earth system requires early (lower division) and for geoscience majors, repeated (upper division) curricular emphasis on the interactions of the lithosphere, hydrosphere, atmosphere, biosphere, and pedosphere across space and through time. Capturing the interest of university students in globally relevant earth system issues and their ethical dimensions while first learning about the earth system is an important initial step in bringing geoethical deliberation and awareness to the next generation of geoscientists. Development of a new introductory Earth System Science course replacing a traditional introductory Physical Geology course at Montana State University has involved abandonment of concept-based content organization in favor of a place-based approach incorporating examination of the complex interactions of earth system components and emergent issues and dilemmas deriving from the unique component interactions that characterize each locale. Thirteen different place-based week-long modules (using web- and classroom-based instruction) were developed to ensure cumulative broad coverage across the earth geographically and earth system components conceptually. Each place-based instructional module contains content of societal relevance requiring synthesis, critical evaluation, and reflection by students. Examples include making linkages between deforestation driven by economics and increased seismicity in Haiti, agriculture and development of marine dead zones in the Gulf of Mexico, glacier melting and alpine ecotone migration due to global warming in Glacier National Park, USA, and destruction of Caribbean mangrove forests and its negative effects on coral reef biodiversity.
Biology as a Key Technological Foundation for Settlement Beyond Earth
NASA Technical Reports Server (NTRS)
Rothschild, L. J.; Navarrete, J.; Kent, R. E.; McCutcheon, G.; Pless, E.; Paulino-Lima, I. G.
2017-01-01
Moving materials beyond Earth, whether spacecraft, living organisms, or both, is limited by mass constraints. Yet human survival requires an extensive infrastructure, from environmental regulation to life support. In practice this means habitats, food, oxygen, waste recycling, medicine and so on. Thus, there is a mismatch between what will be required in transit and at destination to fulfill dreams of human settlements and what can realistically moved there. Further, settlement off planet with current transportation systems requires the ability to operate independently of the Earth for prolonged periods of time, requiring long-term storage of supplies and the flexibilityto satisfy new needs.
EOS situational data shared service mechanism
NASA Astrophysics Data System (ADS)
Lv, L.; Xu, Q.; Lan, C. Z.; Shi, Q. S.; Lu, W. J.; Wu, W. Q.
2016-11-01
With the rapid development of aerospace and remote sensing technology, various high-resolution Earth Observation Systems (EOS) are widely used in economic, social, military and other fields and playing an increasingly prominent role in the construction of Digital Earth and national strategic planning. The normal operation of the system is the premise of high quality data acquisition. Compared with the ground observation mode, EOS itself and the surrounding environment are more complex, and its operation control mainly depends on all kinds of Space Situational Awareness (SSA) data acquisition and analysis. SSA data has more extensive sources, larger volume, stronger time-effectiveness and more complicated structure than traditional geographical spatial data. For effective data sharing and utilization, combined with the analysis of data types and structures, a SSA data sharing identity language SSDSML is designed based on the extensible mark-up language XML, which realizes a comprehensive description of satellites and their attributes, space environment, ground stations, etc. Then EOS situational data shared service mechanism is established and provides a powerful data support for the normal operation of the system.
Stable habitable zones of single Jovian planet systems
NASA Astrophysics Data System (ADS)
Agnew, Matthew T.; Maddison, Sarah T.; Thilliez, Elodie; Horner, Jonathan
2017-11-01
With continued improvement in telescope sensitivity and observational techniques, the search for rocky planets in stellar habitable zones is entering an exciting era. With so many exoplanetary systems available for follow-up observations to find potentially habitable planets, one needs to prioritize the ever-growing list of candidates. We aim to determine which of the known planetary systems are dynamically capable of hosting rocky planets in their habitable zones, with the goal of helping to focus future planet search programmes. We perform an extensive suite of numerical simulations to identify regions in the habitable zones of single Jovian planet systems where Earth-mass planets could maintain stable orbits, specifically focusing on the systems in the Catalog of Earth-like Exoplanet Survey Targets (CELESTA). We find that small, Earth-mass planets can maintain stable orbits in cases where the habitable zone is largely, or partially, unperturbed by a nearby Jovian, and that mutual gravitational interactions and resonant mechanisms are capable of producing stable orbits even in habitable zones that are significantly or completely disrupted by a Jovian. Our results yield a list of 13 single Jovian planet systems in CELESTA that are not only capable of supporting an Earth-mass planet on stable orbits in their habitable zone, but for which we are also able to constrain the orbits of the Earth-mass planet such that the induced radial velocity signals would be detectable with next generation instruments.
Fission Systems for Mars Exploration
NASA Technical Reports Server (NTRS)
Houts, Michael G.; Kim, T.; Dorney, D. J.; Swint, Marion Shayne
2012-01-01
Fission systems are used extensively on earth, and 34 such systems have flown in space. The energy density of fission is over 10 million times that of chemical reactions, giving fission the potential to eliminate energy density constraints for many space missions. Potential safety and operational concerns with fission systems are well understood, and strategies exist for affordably developing such systems. By enabling a power-rich environment and highly efficient propulsion, fission systems could enable affordable, sustainable exploration of Mars.
Sustained Satellite Missions for Climate Data Records
NASA Technical Reports Server (NTRS)
Halpern, David
2012-01-01
Satellite CDRs possess the accuracy, longevity, and stability for sustained moni toring of critical variables to enhance understanding of the global integrated Earth system and predict future conditions. center dot Satellite CDRs are a critical element of a global climate observing system. center dot Satellite CDRs are a difficult challenge and require high - level managerial commitment, extensive intellectual capital, and adequate funding.
NASA Technical Reports Server (NTRS)
Zhu, Dongming; Chen, Yuan L.; Miller, Robert A.
2004-01-01
Advanced thermal barrier coatings (TBCs) have been developed by incorporating multicomponent rare earth oxide dopants into zirconia-based thermal barrier coatings to promote the creation of the thermodynamically stable, immobile oxide defect clusters and/or nanophases within the coating systems. In this paper, the defect clusters, induced by Nd, Gd, and Yb rare earth dopants in the zirconia-yttria thermal barrier coatings, were characterized by high-resolution transmission electron microscopy (TEM). The TEM lattice imaging, selected area diffraction (SAD), and electron energy-loss spectroscopy (EELS) analyses demonstrated that the extensive nanoscale rare earth dopant segregation exists in the plasma-sprayed and electron-physical-vapor-deposited (EB PVD) thermal barrier coatings. The nanoscale concentration heterogeneity and the resulting large lattice distortion promoted the formation of parallel and rotational defective lattice clusters in the coating systems. The presence of the 5-to 100-nm-sized defect clusters and nanophases is believed to be responsible for the significant reduction of thermal conductivity, improved sintering resistance, and long-term high temperature stability of the advanced thermal barrier coating systems.
EOforge: Generic Open Framework for Earth Observation Data Processing Systems
2006-09-01
Allow the use of existing interfaces, i.e. MUIS: ESA multimission catalogue for EO products. • Support last EO systems technologies, i.e. MASS ...5. Extensibility and configurability to allow customisation and the inclusion of new functionality. 6. Multi-instrument and multi-mission processing...such as: • MUIS: ESA multimission catalogue for EO products. • MASS (Multi-Application Support Service System): ESA web services technology standard
Early Planetary Differentiation: Comparative Planetology
NASA Technical Reports Server (NTRS)
Jones, John H.
2006-01-01
We currently have extensive data for four different terrestrial bodies of the inner solar system: Earth, the Moon, Mars, and the Eucrite Parent Body [EPB]. All formed early cores; but all(?) have mantles with elevated concentrations of highly sidero-phile elements, suggestive of the addition of a late "veneer". Two appear to have undergone extensive differentiation consistent with a global magma ocean. One appears to be inconsistent with a simple model of "low-pressure" chondritic differentiation. Thus, there seems to be no single, simple paradigm for understand-ing early differentiation.
Greenwood, Richard C; Barrat, Jean-Alix; Miller, Martin F; Anand, Mahesh; Dauphas, Nicolas; Franchi, Ian A; Sillard, Patrick; Starkey, Natalie A
2018-03-01
The Earth-Moon system likely formed as a result of a collision between two large planetary objects. Debate about their relative masses, the impact energy involved, and the extent of isotopic homogenization continues. We present the results of a high-precision oxygen isotope study of an extensive suite of lunar and terrestrial samples. We demonstrate that lunar rocks and terrestrial basalts show a 3 to 4 ppm (parts per million), statistically resolvable, difference in Δ 17 O. Taking aubrite meteorites as a candidate impactor material, we show that the giant impact scenario involved nearly complete mixing between the target and impactor. Alternatively, the degree of similarity between the Δ 17 O values of the impactor and the proto-Earth must have been significantly closer than that between Earth and aubrites. If the Earth-Moon system evolved from an initially highly vaporized and isotopically homogenized state, as indicated by recent dynamical models, then the terrestrial basalt-lunar oxygen isotope difference detected by our study may be a reflection of post-giant impact additions to Earth. On the basis of this assumption, our data indicate that post-giant impact additions to Earth could have contributed between 5 and 30% of Earth's water, depending on global water estimates. Consequently, our data indicate that the bulk of Earth's water was accreted before the giant impact and not later, as often proposed.
Ceos Wgiss Common Framework for Wgiss Connected Data Assets
NASA Astrophysics Data System (ADS)
Enloe, Y.; Mitchell, A. E.; Albani, M.; Yapur, M.
2016-12-01
The Committee on Earth Observation Satellites (CEOS), established in 1984 to coordinate civil space-borne observations of the Earth, has been building through its Working Group on Information Systems and Services (WGISS), a common data framework to identify and connect data assets at member agencies. Some of these data assets are federated systems such as the CEOS WGISS Integrated Catalog (CWIC), the European Space Agency's FedEO (Federated Earth Observations Missions Access) system, and the International Directory Network (IDN) which is an international effort developed by NASA to assist researchers in locating information on available data sets. A system level team provides coordination and oversight to make this loosely coupled federated system function and evolve. WGISS has identified 2 search standards, the Open Geospatial Consortium (OGC) Catalog Services for the Web (CSW) and the CEOS OpenSearch Best Practices (which references the OGC OpenSearch Geo and Time Extensions and OGC OpenSearch Extension for Earth Observation) as well as an interoperable metadata standard (ISO 19115) for use within the WGISS Connected Assets. Data partners must register their data collections in the IDN using the Global Change Master Directory (GCMD) Keywords. Data partners need to support one of the 2 search standards and be able to map their internal metadata to the ISO 19115 metadata elements. All searchable data must have a data access path. Clients can offer search and access to all or a subset of the satellite data available through the WGISS Connected Data Assets. Clients can offer support for a 2-step search: (1) Discovery through collection search using platform, instrument, science keywords, etc. at the IDN and (2) Search granule metadata at data partners through CWIC or FedEO. There are more than a dozen international agencies that offer their data through the WGISS Federation or working on developing their connections. This list includes European Space Agency, NASA, NOAA, USGS, National Institute for Space Research (Brazil), Canadian Center for Mapping and Earth Observations (CCMEO), the Academy for Opto-Electronics (China), the Indian Space Research Organization (ISRO), EUMETSAT, Russian Federal Space Agency (ROSCOSMOS) and several agencies within Australia.
Visualization of Wind Data on Google Earth for the Three-dimensional Wind Field (3DWF) Model
2012-09-01
ActiveX components or XPCOM extensions can be used by JavaScript to write data to the local file system. Since there is an inherent risk, it is very...important to only use these types of objects ( ActiveX or XPCOM) from a trusted source in order to minimize the exposure of a computer system to malware
The integrated Earth system model version 1: formulation and functionality
Collins, W. D.; Craig, A. P.; Truesdale, J. E.; ...
2015-07-23
The integrated Earth system model (iESM) has been developed as a new tool for projecting the joint human/climate system. The iESM is based upon coupling an integrated assessment model (IAM) and an Earth system model (ESM) into a common modeling infrastructure. IAMs are the primary tool for describing the human–Earth system, including the sources of global greenhouse gases (GHGs) and short-lived species (SLS), land use and land cover change (LULCC), and other resource-related drivers of anthropogenic climate change. ESMs are the primary scientific tools for examining the physical, chemical, and biogeochemical impacts of human-induced changes to the climate system. Themore » iESM project integrates the economic and human-dimension modeling of an IAM and a fully coupled ESM within a single simulation system while maintaining the separability of each model if needed. Both IAM and ESM codes are developed and used by large communities and have been extensively applied in recent national and international climate assessments. By introducing heretofore-omitted feedbacks between natural and societal drivers, we can improve scientific understanding of the human–Earth system dynamics. Potential applications include studies of the interactions and feedbacks leading to the timing, scale, and geographic distribution of emissions trajectories and other human influences, corresponding climate effects, and the subsequent impacts of a changing climate on human and natural systems. This paper describes the formulation, requirements, implementation, testing, and resulting functionality of the first version of the iESM released to the global climate community.« less
HEMCO v1.0: A Versatile, ESMF-Compliant Component for Calculating Emissions in Atmospheric Models
NASA Technical Reports Server (NTRS)
Keller, C. A.; Long, M. S.; Yantosca, R. M.; Da Silva, A. M.; Pawson, S.; Jacob, D. J.
2014-01-01
We describe the Harvard-NASA Emission Component version 1.0 (HEMCO), a stand-alone software component for computing emissions in global atmospheric models. HEMCO determines emissions from different sources, regions, and species on a user-defined grid and can combine, overlay, and update a set of data inventories and scale factors, as specified by the user through the HEMCO configuration file. New emission inventories at any spatial and temporal resolution are readily added to HEMCO and can be accessed by the user without any preprocessing of the data files or modification of the source code. Emissions that depend on dynamic source types and local environmental variables such as wind speed or surface temperature are calculated in separate HEMCO extensions. HEMCO is fully compliant with the Earth System Modeling Framework (ESMF) environment. It is highly portable and can be deployed in a new model environment with only few adjustments at the top-level interface. So far, we have implemented HEMCO in the NASA Goddard Earth Observing System (GEOS-5) Earth system model (ESM) and in the GEOS-Chem chemical transport model (CTM). By providing a widely applicable framework for specifying constituent emissions, HEMCO is designed to ease sensitivity studies and model comparisons, as well as inverse modeling in which emissions are adjusted iteratively. The HEMCO code, extensions, and the full set of emissions data files used in GEOS-Chem are available at http: //wiki.geos-chem.org/HEMCO.
Deep Space Transportation System Using the Sun-Earth L2 Point
NASA Technical Reports Server (NTRS)
Matsumoto, Michihiro
2007-01-01
Recently, various kinds of planetary explorations have become more feasible, taking the advantage of low thrust propulsion means such as ion engines that have come into practical use. The field of space activity has now been expanded even to the rim of the outer solar system. In this context, the Japan Aerospace Exploration Agency (JAXA) has started investigating a Deep Space Port built at the L2 Lagrange point in the Sun-Earth system. For the purpose of making the deep space port practically useful, there is a need to establish a method to making spaceship depart and return from/to the port. This paper first discusses the escape maneuvers originating from the L2 point under the restricted three-body problem. Impulsive maneuvers from the L2 point are extensively studied here, and using the results, optimal low-thrust escape strategies are synthesized. Furthermore, this paper proposes the optimal escape and acceleration maneuvers schemes using Electric Delta-V Earth Gravity Assist (EDVEGA) technique.
NASA Technical Reports Server (NTRS)
Forrest, R. B.; Eppes, T. A.; Ouellette, R. J.
1973-01-01
Studies were performed to evaluate various image positioning methods for possible use in the earth observatory satellite (EOS) program and other earth resource imaging satellite programs. The primary goal is the generation of geometrically corrected and registered images, positioned with respect to the earth's surface. The EOS sensors which were considered were the thematic mapper, the return beam vidicon camera, and the high resolution pointable imager. The image positioning methods evaluated consisted of various combinations of satellite data and ground control points. It was concluded that EOS attitude control system design must be considered as a part of the image positioning problem for EOS, along with image sensor design and ground image processing system design. Study results show that, with suitable efficiency for ground control point selection and matching activities during data processing, extensive reliance should be placed on use of ground control points for positioning the images obtained from EOS and similar programs.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Jacobson, R. A., E-mail: robert.jacobson@jpl.nasa.gov
2014-11-01
French et al. determined the orbits of the Uranian rings, the orientation of the pole of Uranus, and the gravity harmonics of Uranus from Earth-based and Voyager ring occultations. Jacobson et al. determined the orbits of the Uranian satellites and the masses of Uranus and its satellites from Earth-based astrometry and observations acquired with the Voyager 2 spacecraft; they used the gravity harmonics and pole from French et al. Jacobson and Rush reconstructed the Voyager 2 trajectory and redetermined the Uranian system gravity parameters, satellite orbits, and ring orbits in a combined analysis of the data used previously augmented withmore » additional Earth-based astrometry. Here we report on an extension of that work that incorporates additional astrometry and ring occultations together with improved data processing techniques.« less
International Education for Spaceship Earth.
ERIC Educational Resources Information Center
King, David C.
This book is based on an extensive study conducted by the Foreign Policy Association for the United States Office of Education on needs and priorities in international education. To give students adequate preparation for today's world of constant and rapid change the schools must help them gain a global perspective of the world as a single system.…
Climate Reanalysis: Progress and Future Prospects
NASA Technical Reports Server (NTRS)
Gelaro, Ron
2018-01-01
Reanalysis is the process whereby an unchanging data assimilation system is used to provide a consistent reprocessing of observations, typically spanning an extended segment of the historical data record. The process relies on an underlying model to combine often-disparate observations in a physically consistent manner, enabling production of gridded data sets for a broad range of applications including the study of historical weather events, preparation of climatologies, business sector development and, more recently, climate monitoring. Over the last few decades, several generations of reanalyses of the global atmosphere have been produced by various operational and research centers, focusing more or less on the period of regular conventional and satellite observations beginning in the mid to late twentieth century. There have also been successful efforts to extend atmospheric reanalyses back to the late nineteenth and early twentieth centuries, using mostly surface observations. Much progress has resulted from (and contributed to) advancements in numerical weather prediction, especially improved models and data assimilation techniques, increased computing capacity, the availability of new observation types and efforts to recover and improve the quality of historical ones. The recent extension of forecast systems that allow integrated modeling of meteorological, oceanic, land surface, and chemical variables provide the basic elements for coupled data assimilation. This has opened the door to the development of a new generation of coupled reanalyses of the Earth system, or integrated Earth system analyses (IESA). Evidence so far suggests that this approach can improve the analysis of currently uncoupled components of the Earth system, especially at their interface, and lead to increased predictability. However, extensive analysis coupling as envisioned for IESA, while progressing, still presents significant challenges. These include model biases that can be exacerbated when coupled, component systems with different physical characteristics and different spatial and temporal scales, and component observations in different media with different spatial and temporal frequencies and different latencies. Quantification of uncertainty in reanalyses is also a critical challenge and is important for expanding their utility as a tool for climate change assessment. This talk provides a brief overview of the progress of reanalysis development during recent decades, and describes remaining challenges in the progression toward coupled Earth system reanalyses.
NASA Technical Reports Server (NTRS)
Allaway, H.
1979-01-01
The concept of the orbital flight of the space shuttle and the development of the space transportation system are addressed. How the system came to be, why it is designed the way it is, what is expected of it, and how it may grow are among the questions considered. Emphasis is placed on the effect of the space transportation system on U.S. space exploration in the next decade, including plans to make space an extension of life on the Earth's surface.
NASA Astrophysics Data System (ADS)
Grunskaya, L. V.; Isakevich, V. V.; Isakevich, D. V.
2018-05-01
A system is constructed, which, on the basis of extensive experimental material and the use of eigenoscopy, has allowed us to detect anomalies in the spectra of uncorrelated components localized near the rotation frequencies and twice the rotation frequencies of relativistic binary star systems with vanishingly low probability of false alarm, not exceeding 10-17.
Lessons Learned while Exploring Cloud-Native Architectures for NASA EOSDIS Applications and Systems
NASA Astrophysics Data System (ADS)
Pilone, D.
2016-12-01
As new, high data rate missions begin collecting data, the NASA's Earth Observing System Data and Information System (EOSDIS) archive is projected to grow roughly 20x to over 300PBs by 2025. To prepare for the dramatic increase in data and enable broad scientific inquiry into larger time series and datasets, NASA has been exploring the impact of applying cloud technologies throughout EOSDIS. In this talk we will provide an overview of NASA's prototyping and lessons learned in applying cloud architectures to: Highly scalable and extensible ingest and archive of EOSDIS data Going "all-in" on cloud based application architectures including "serverless" data processing pipelines and evaluating approaches to vendor-lock in Rethinking data distribution and approaches to analysis in a cloud environment Incorporating and enforcing security controls while minimizing the barrier for research efforts to deploy to NASA compliant, operational environments. NASA's Earth Observing System (EOS) is a coordinated series of satellites for long term global observations. NASA's Earth Observing System Data and Information System (EOSDIS) is a multi-petabyte-scale archive of environmental data that supports global climate change research by providing end-to-end services from EOS instrument data collection to science data processing to full access to EOS and other earth science data. On a daily basis, the EOSDIS ingests, processes, archives and distributes over 3 terabytes of data from NASA's Earth Science missions representing over 6000 data products ranging from various types of science disciplines. EOSDIS has continually evolved to improve the discoverability, accessibility, and usability of high-impact NASA data spanning the multi-petabyte-scale archive of Earth science data products.
Understanding climate: A strategy for climate modeling and predictability research, 1985-1995
NASA Technical Reports Server (NTRS)
Thiele, O. (Editor); Schiffer, R. A. (Editor)
1985-01-01
The emphasis of the NASA strategy for climate modeling and predictability research is on the utilization of space technology to understand the processes which control the Earth's climate system and it's sensitivity to natural and man-induced changes and to assess the possibilities for climate prediction on time scales of from about two weeks to several decades. Because the climate is a complex multi-phenomena system, which interacts on a wide range of space and time scales, the diversity of scientific problems addressed requires a hierarchy of models along with the application of modern empirical and statistical techniques which exploit the extensive current and potential future global data sets afforded by space observations. Observing system simulation experiments, exploiting these models and data, will also provide the foundation for the future climate space observing system, e.g., Earth observing system (EOS), 1985; Tropical Rainfall Measuring Mission (TRMM) North, et al. NASA, 1984.
The Search for Extraterrestrial Life
NASA Astrophysics Data System (ADS)
Peter, Ulmschneider
Looking at the nature, origin, and evolution of life on Earth is one way of assessing whether extraterrestrial life exists on Earth-like planets elsewhere (see Chaps. 5 and 6). A more direct approach is to search for favorable conditions and traces of life on other celestial bodies, both in the solar system and beyond. Clearly, there is little chance of encountering nonhuman intelligent beings in the solar system. But there could well be primitive life on Mars, particularly as in the early history of the solar system the conditions on Mars were quite similar to those on Earth. In addition, surprisingly favorable conditions for life once existed on the moons of Jupiter. Yet even if extraterrestrial life is not encountered in forthcoming space missions, it would be of utmost importance to recover fossils of past organisms as such traces would greatly contribute to our basic understanding of the formation of life. In addition to the planned missions to Mars and Europa, there are extensive efforts to search for life outside the solar system. Rapid advances in the detection of extrasolar planets, outlined in Chap. 3, are expected to lead to the discovery of Earth-like planets in the near future. But how can we detect life on these distant bodies?
NASA Astrophysics Data System (ADS)
Sahagian, D.; Prentice, C.
2004-12-01
A great deal of time, effort and resources have been expended on global change research to date, but dissemination and visualization of the key pertinent data sets has been problematical. Toward that end, we are constructing an Earth System Atlas which will serve as a single compendium describing the state of the art in our understanding of the Earth system and how it has responded to and is likely to respond to natural and anthropogenic perturbations. The Atlas is an interactive web-based system of data bases and data manipulation tools and so is much more than a collection of pre-made maps posted on the web. It represents a tool for assembling, manipulating, and displaying specific data as selected and customized by the user. Maps are created "on the fly" according to user-specified instructions. The information contained in the Atlas represents the growing body of data assembled by the broader Earth system research community, and can be displayed in the form of maps and time series of the various relevant parameters that drive and are driven by changes in the Earth system at various time scales. The Atlas is designed to display the information assembled by the global change research community in the form of maps and time series of all the relevant parameters that drive or are driven by changes in the Earth System at various time scales. This will serve to provide existing data to the community, but also will help to highlight data gaps that may hinder our understanding of critical components of the Earth system. This new approach to handling Earth system data is unique in several ways. First and foremost, data must be peer-reviewed. Further, it is designed to draw on the expertise and products of extensive international research networks rather than on a limited number of projects or institutions. It provides explanatory explanations targeted to the user's needs, and the display of maps and time series can be customize by the user. In general, the Atlas is designed provide the research community with a new opportunity for data observation and manipulation, enabling new scientific discoveries in the coming years. An initial prototype of the Atlas has been developed and can be manipulated in real time.
Sustaining Human Presence on Mars Using ISRU and a Reusable Lander
NASA Technical Reports Server (NTRS)
Arney, Dale C.; Jones, Christopher A.; Klovstad, Jordan J.; Komar, D.R.; Earle, Kevin; Moses, Robert; Shyface, Hilary R.
2015-01-01
This paper presents an analysis of the impact of ISRU (In-Site Resource Utilization), reusability, and automation on sustaining a human presence on Mars, requiring a transition from Earth dependence to Earth independence. The study analyzes the surface and transportation architectures and compared campaigns that revealed the importance of ISRU and reusability. A reusable Mars lander, Hercules, eliminates the need to deliver a new descent and ascent stage with each cargo and crew delivery to Mars, reducing the mass delivered from Earth. As part of an evolvable transportation architecture, this investment is key to enabling continuous human presence on Mars. The extensive use of ISRU reduces the logistics supply chain from Earth in order to support population growth at Mars. Reliable and autonomous systems, in conjunction with robotics, are required to enable ISRU architectures as systems must operate and maintain themselves while the crew is not present. A comparison of Mars campaigns is presented to show the impact of adding these investments and their ability to contribute to sustaining a human presence on Mars.
NASA Technical Reports Server (NTRS)
Robertson, Franklin; Goodman, Steven J.; Christy, John R.; Fitzjarrald, Daniel E.; Chou, Shi-Hung; Crosson, William; Wang, Shouping; Ramirez, Jorge
1993-01-01
This research is the MSFC component of a joint MSFC/Pennsylvania State University Eos Interdisciplinary Investigation on the global water cycle extension across the earth sciences. The primary long-term objective of this investigation is to determine the scope and interactions of the global water cycle with all components of the Earth system and to understand how it stimulates and regulates change on both global and regional scales. Significant accomplishments in the past year are presented and include the following: (1) water vapor variability; (2) multi-phase water analysis; (3) global modeling; and (4) optimal precipitation and stream flow analysis and hydrologic processes.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Collins, William D.; Craig, Anthony P.; Truesdale, John E.
The integrated Earth System Model (iESM) has been developed as a new tool for pro- jecting the joint human/climate system. The iESM is based upon coupling an Integrated Assessment Model (IAM) and an Earth System Model (ESM) into a common modeling in- frastructure. IAMs are the primary tool for describing the human–Earth system, including the sources of global greenhouse gases (GHGs) and short-lived species, land use and land cover change, and other resource-related drivers of anthropogenic climate change. ESMs are the primary scientific tools for examining the physical, chemical, and biogeochemical impacts of human-induced changes to the climate system. Themore » iESM project integrates the economic and human dimension modeling of an IAM and a fully coupled ESM within a sin- gle simulation system while maintaining the separability of each model if needed. Both IAM and ESM codes are developed and used by large communities and have been extensively applied in recent national and international climate assessments. By introducing heretofore- omitted feedbacks between natural and societal drivers, we can improve scientific under- standing of the human–Earth system dynamics. Potential applications include studies of the interactions and feedbacks leading to the timing, scale, and geographic distribution of emissions trajectories and other human influences, corresponding climate effects, and the subsequent impacts of a changing climate on human and natural systems. This paper de- scribes the formulation, requirements, implementation, testing, and resulting functionality of the first version of the iESM released to the global climate community.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Collins, W. D.; Craig, A. P.; Truesdale, J. E.
The integrated Earth system model (iESM) has been developed as a new tool for projecting the joint human/climate system. The iESM is based upon coupling an integrated assessment model (IAM) and an Earth system model (ESM) into a common modeling infrastructure. IAMs are the primary tool for describing the human–Earth system, including the sources of global greenhouse gases (GHGs) and short-lived species (SLS), land use and land cover change (LULCC), and other resource-related drivers of anthropogenic climate change. ESMs are the primary scientific tools for examining the physical, chemical, and biogeochemical impacts of human-induced changes to the climate system. Themore » iESM project integrates the economic and human-dimension modeling of an IAM and a fully coupled ESM within a single simulation system while maintaining the separability of each model if needed. Both IAM and ESM codes are developed and used by large communities and have been extensively applied in recent national and international climate assessments. By introducing heretofore-omitted feedbacks between natural and societal drivers, we can improve scientific understanding of the human–Earth system dynamics. Potential applications include studies of the interactions and feedbacks leading to the timing, scale, and geographic distribution of emissions trajectories and other human influences, corresponding climate effects, and the subsequent impacts of a changing climate on human and natural systems. This paper describes the formulation, requirements, implementation, testing, and resulting functionality of the first version of the iESM released to the global climate community.« less
Activities involving aeronautical, space science, and technology support for minority institutions
NASA Technical Reports Server (NTRS)
1993-01-01
The Final Report addressed the activities with which the Interracial Council for Business Opportunity (ICBO) was involved over the past 12 months. ICBO was involved in the design and development of a CARES Student Tracking System Software (CARES). Cares is intended to provide an effective means of maintaining relevant current and historical information on NASA-funded students through a range of educational program initiatives. ICBP was extensively involved in the formation of a minority university consortium amd implementation of collaborative research activities by the consortium as part of NASA's Mission to Planet Earth/Earth Observing System. ICBO was involved in the formation of an HBCU/MI Consortium to facilitate technology transfer efforts to the small and minority business community in their respective regions.
Geometric error analysis for shuttle imaging spectrometer experiment
NASA Technical Reports Server (NTRS)
Wang, S. J.; Ih, C. H.
1984-01-01
The demand of more powerful tools for remote sensing and management of earth resources steadily increased over the last decade. With the recent advancement of area array detectors, high resolution multichannel imaging spectrometers can be realistically constructed. The error analysis study for the Shuttle Imaging Spectrometer Experiment system is documented for the purpose of providing information for design, tradeoff, and performance prediction. Error sources including the Shuttle attitude determination and control system, instrument pointing and misalignment, disturbances, ephemeris, Earth rotation, etc., were investigated. Geometric error mapping functions were developed, characterized, and illustrated extensively with tables and charts. Selected ground patterns and the corresponding image distortions were generated for direct visual inspection of how the various error sources affect the appearance of the ground object images.
An improved model of the Earth's gravitational field: GEM-T1
NASA Technical Reports Server (NTRS)
Marsh, J. G.; Lerch, F. J.; Christodoulidis, D. C.; Putney, B. H.; Felsentreger, T. L.; Sanchez, B. V.; Smith, D. E.; Klosko, S. M.; Martin, T. V.; Pavlis, E. C.
1987-01-01
Goddard Earth Model T1 (GEM-T1), which was developed from an analysis of direct satellite tracking observations, is the first in a new series of such models. GEM-T1 is complete to degree and order 36. It was developed using consistent reference parameters and extensive earth and ocean tidal models. It was simultaneously solved for gravitational and tidal terms, earth orientation parameters, and the orbital parameters of 580 individual satellite arcs. The solution used only satellite tracking data acquired on 17 different satellites and is predominantly based upon the precise laser data taken by third generation systems. In all, 800,000 observations were used. A major improvement in field accuracy was obtained. For marine geodetic applications, long wavelength geoidal modeling is twice as good as in earlier satellite-only GEM models. Orbit determination accuracy has also been substantially advanced over a wide range of satellites that have been tested.
NASA Technical Reports Server (NTRS)
Marr, Greg C.
2003-01-01
The Triana spacecraft was designed to be launched by the Space Shuttle. The nominal Triana mission orbit will be a Sun-Earth L1 libration point orbit. Using the NASA Goddard Space Flight Center's Orbit Determination Error Analysis System (ODEAS), orbit determination (OD) error analysis results are presented for all phases of the Triana mission from the first correction maneuver through approximately launch plus 6 months. Results are also presented for the science data collection phase of the Fourier Kelvin Stellar Interferometer Sun-Earth L2 libration point mission concept with momentum unloading thrust perturbations during the tracking arc. The Triana analysis includes extensive analysis of an initial short arc orbit determination solution and results using both Deep Space Network (DSN) and commercial Universal Space Network (USN) statistics. These results could be utilized in support of future Sun-Earth libration point missions.
NASA Astrophysics Data System (ADS)
Pavlos, G. P.; Malandraki, O.; Khabarova, O.; Livadiotis, G.; Pavlos, E.; Karakatsanis, L. P.; Iliopoulos, A. C.; Parisis, K.
2017-12-01
In this work we study the non-extensivity of Solar Wind space plasma by using electric-magnetic field data obtained by in situ spacecraft observations at different dynamical states of solar wind system especially in interplanetary coronal mass ejections (ICMEs), Interplanetary shocks, magnetic islands, or near the Earth Bow shock. Especially, we study the energetic particle non extensive fractional acceleration mechanism producing kappa distributions as well as the intermittent turbulence mechanism producing multifractal structures related with the Tsallis q-entropy principle. We present some new and significant results concerning the dynamics of ICMEs observed in the near Earth at L1 solar wind environment, as well as its effect in Earth's magnetosphere as well as magnetic islands. In-situ measurements of energetic particles at L1 are analyzed, in response to major solar eruptive events at the Sun (intense flares, fast CMEs). The statistical characteristics are obtained and compared for the Solar Energetic Particles (SEPs) originating at the Sun, the energetic particle enhancements associated with local acceleration during the CME-driven shock passage over the spacecraft (Energetic Particle Enhancements, ESPs) as well as the energetic particle signatures observed during the passage of the ICME. The results are referred to Tsallis non-extensive statistics and in particular to the estimation of Tsallis q-triplet, (qstat, qsen, qrel) of electric-magnetic field and the kappa distributions of solar energetic particles time series of the ICME, magnetic islands, resulting from the solar eruptive activity or the internal Solar Wind dynamics. Our results reveal significant differences in statistical and dynamical features, indicating important variations of the magnetic field dynamics both in time and space domains during the shock event, in terms of rate of entropy production, relaxation dynamics and non-equilibrium meta-stable stationary states.
NASA Technical Reports Server (NTRS)
1982-01-01
The Space Operations Center (SOC) orbital space station missions are analyzed. Telecommunications missions, space science, Earth sensing, and space testing missions, research and applications missions, defense missions, and satellite servicing missions are modeled and mission needs discussed. The satellite servicing missions are analyzed in detail, including construction and servicing equipment requirements, mission needs and benefits, differential drag characteristics of co-orbiting satellites, and satellite servicing transportation requirements.
NASA Astrophysics Data System (ADS)
Jöckel, Patrick; Tost, Holger; Pozzer, Andrea; Kunze, Markus; Kirner, Oliver; Brenninkmeijer, Carl A. M.; Brinkop, Sabine; Cai, Duy S.; Dyroff, Christoph; Eckstein, Johannes; Frank, Franziska; Garny, Hella; Gottschaldt, Klaus-Dirk; Graf, Phoebe; Grewe, Volker; Kerkweg, Astrid; Kern, Bastian; Matthes, Sigrun; Mertens, Mariano; Meul, Stefanie; Neumaier, Marco; Nützel, Matthias; Oberländer-Hayn, Sophie; Ruhnke, Roland; Runde, Theresa; Sander, Rolf; Scharffe, Dieter; Zahn, Andreas
2016-03-01
Three types of reference simulations, as recommended by the Chemistry-Climate Model Initiative (CCMI), have been performed with version 2.51 of the European Centre for Medium-Range Weather Forecasts - Hamburg (ECHAM)/Modular Earth Submodel System (MESSy) Atmospheric Chemistry (EMAC) model: hindcast simulations (1950-2011), hindcast simulations with specified dynamics (1979-2013), i.e. nudged towards ERA-Interim reanalysis data, and combined hindcast and projection simulations (1950-2100). The manuscript summarizes the updates of the model system and details the different model set-ups used, including the on-line calculated diagnostics. Simulations have been performed with two different nudging set-ups, with and without interactive tropospheric aerosol, and with and without a coupled ocean model. Two different vertical resolutions have been applied. The on-line calculated sources and sinks of reactive species are quantified and a first evaluation of the simulation results from a global perspective is provided as a quality check of the data. The focus is on the intercomparison of the different model set-ups. The simulation data will become publicly available via CCMI and the Climate and Environmental Retrieval and Archive (CERA) database of the German Climate Computing Centre (DKRZ). This manuscript is intended to serve as an extensive reference for further analyses of the Earth System Chemistry integrated Modelling (ESCiMo) simulations.
NASA Astrophysics Data System (ADS)
Ballantyne, A. P.; Miller, J. B.; Bowling, D. R.; Tans, P. P.; Baker, I. T.
2013-12-01
The global cycles of water and carbon are inextricably linked through photosynthesis. This link is largely governed by stomatal conductance that regulates water loss to the atmosphere and carbon gain to the biosphere. Although extensive research has focused on the response of stomatal conductance to increased atmospheric CO2, much less research has focused on the response of stomatal conductance to concomitant climate change. Here we make use of intensive and extensive measurements of C isotopes in source CO2 to the atmosphere (del-bio) to make inferences about stomatal response to climatic factors at a single forest site and across a network of global observation sites. Based on intensive observations at the Niwot Ridge Ameriflux site we discover that del-bio is an excellent physical proxy of stomatal response during the growing season and this response is highly sensitive to atmospheric water vapor pressure deficit (VPD). We use these intensive single forest site observations to inform our analysis of the global observation network, focusing in on the growing season across an array of terrestrial sites. We find that stomatal response across most of these terrestrial sites is also highly sensitive to VPD. Lastly, we simulate the response of future climate change on stomatal response and discover that future increases in VPD may limit the biosphere's capacity to assimilate future CO2 emissions. These results have direct implications for the benchmarking of Earth System Models as stomatal conductance in many of these models does not vary as a function of VPD.
NASA Astrophysics Data System (ADS)
Baker, V. R.
2013-12-01
Planetary habitability may fluctuate episodically against a background provided by the co-evolution of a planet's mineral/rock (geosphere) components and its water (hydrosphere) in relation to its position in a circumstellar system. The water/rock (geosphere/hydrosphere) co-evolution can be inferred from the geological histories of the terrestrial planets of the solar system, particularly from the very extensive understanding of Earth and Mars. Habitability and water/rock co-evolution have components that are tychistic (i.e., driven by chance) and anancastic (i.e., dynamically driven largely by deterministic forces). They also have a final, end-directed (i.e., teleomatic) aspect that operates in accordance with natural laws. This is a larger perspective on the idea of planetary habitability than is generally associated with an astronomical approach, and it incorporates additional insights from a geological perspective on the issue. The geological histories of Mars and Earth are punctuated with critical, short-term epochs of extreme change, which for Earth are known to be associated with major disruptions of its biosphere. These catastrophic epochs can be described as a type of non-Darwinian evolution that was envisioned by the geologist Clarence King. In an 1877 paper King proposed that accelerated evolutionary change occurs during sudden environmental disruptions. Such Kingian disruptions in mineral/rock and water evolution mark the planetary histories of Mars and Earth, including the early formation and condensation of a steam atmosphere, an impacting cataclysm at about 3.9 to 4 Ga, episodes of concentrated volcanism and tectonism, and associated rapid changes in the linked atmosphere and hydrosphere. These disruptions are closely tied to migrations of water between different planetary reservoirs, the nature of planetary accretion, the origin of a physically coupled atmosphere and ocean, the prospects for initiating plate tectonics, and punctuated greenhouse-to-icehouse climatic transitions. Recent discoveries from Mars missions reveal the extensive role of water in generating sedimentary rocks, active and relict glacial and periglacial features, aqueous weathering products (clay minerals and sulfates), alluvial fans and deltas, the extensive development of paleolakes, and even a probable, though transient ocean. The latter may have formed episodically, associated with episodes of intensive volcanism that disrupted a water-ice-rich permafrost, thereby transferring much of the hydrosphere f
Earth orbital teleoperator systems evaluation
NASA Technical Reports Server (NTRS)
Shields, N. L., Jr.; Slaughter, P. H.; Brye, R. G.; Henderson, D. E.
1979-01-01
The mechanical extension of the human operator to remote and specialized environments poses a series of complex operational questions. A technical and scientific team was organized to investigate these questions through conducting specific laboratory and analytical studies. The intent of the studies was to determine the human operator requirements for remotely manned systems and to determine the particular effects that various system parameters have on human operator performance. In so doing, certain design criteria based on empirically derived data concerning the ultimate control system, the human operator, were added to the Teleoperator Development Program.
Are Earth System model software engineering practices fit for purpose? A case study.
NASA Astrophysics Data System (ADS)
Easterbrook, S. M.; Johns, T. C.
2009-04-01
We present some analysis and conclusions from a case study of the culture and practices of scientists at the Met Office and Hadley Centre working on the development of software for climate and Earth System models using the MetUM infrastructure. The study examined how scientists think about software correctness, prioritize their requirements in making changes, and develop a shared understanding of the resulting models. We conclude that highly customized techniques driven strongly by scientific research goals have evolved for verification and validation of such models. In a formal software engineering context these represents costly, but invaluable, software integration tests with considerable benefits. The software engineering practices seen also exhibit recognisable features of both agile and open source software development projects - self-organisation of teams consistent with a meritocracy rather than top-down organisation, extensive use of informal communication channels, and software developers who are generally also users and science domain experts. We draw some general conclusions on whether these practices work well, and what new software engineering challenges may lie ahead as Earth System models become ever more complex and petascale computing becomes the norm.
NASA Technical Reports Server (NTRS)
Morey-Holton, Emily; Globus, Ruth K.; Kaplansky, Alexander; Durnova, Galina
2004-01-01
The hindlimb unloading (HU) rodent model is used extensively to study the response of many physiological systems to certain aspects of spaceflight, as well as to disuse and recovery from disuse for Earth benefits. This chapter describes the evolution of HU, and is divided into three sections. The first section examines the characteristics of 1063 articles using or reviewing the HU model, published between 1976 and April 1, 2004. The characteristics include number of publications, journals, countries, major physiological systems, method modifications, species, gender, genetic strains and ages of rodents, experiment duration, and countermeasures. The second section provides a comparison of results between space flown and Hu animals from the 14-day Cosmos 2044 mission. The final section describes modifications to HU required by different experimental paradigms and a method to protect the tail harness for long duration studies. HU in rodents has enabled improved understanding of the responses of the musculoskeletal, cardiovascular, immune, renal, neural, metabolic, and reproductive systems to unloading and/or to reloading on Earth with implications for both long-duration human spaceflight and disuse on Earth.
Smouldering Subsurface Fires in the Earth System
NASA Astrophysics Data System (ADS)
Rein, Guillermo
2010-05-01
Smouldering fires, the slow, low-temperature, flameless form of combustion, are an important phenomena in the Earth system. These fires propagate slowly through organic layers of the forest ground and are responsible for 50% or more of the total biomass consumed during wildfires. Only after the 2002 study of the 1997 extreme haze event in South-East Asia, the scientific community recognised the environmental and economic threats posed by subsurface fires. This was caused by the spread of vast biomass fires in Indonesia, burning below the surface for months during the El Niño climate event. It has been calculated that these fires released between 0.81 and 2.57 Gton of carbon gases (13-40% of global emissions). Large smouldering fires are rare events at the local scale but occur regularly at a global scale. Once ignited, they are particularly difficult to extinguish despite extensive rains or fire-fighting attempts and can persist for long periods of time (months, years) spreading over very extensive areas of forest and deep into the soil. Indeed, these are the oldest continuously burning fires on Earth. Earth scientists are interested in smouldering fires because they destroy large amounts of biomass and cause greater damage to the soil ecosystem than flaming fires do. Moreover, these fires cannot be detected with current satellite remote sensing technologies causing inconsistencies between emission inventories and model predictions. Organic soils sustain smouldering fire (hummus, duff, peat and coal) which total carbon pool exceeds that of the world's forests or the atmosphere. This have important implications for climate change. Warmer temperatures at high latitudes are resulting in unprecedented permafrost thaw that is leaving large soil carbon pools exposed to fires. Because the CO2 flux from peat fires has been measured to be about 3000 times larger that the natural degradation flux, permafrost thaw is a risk for greater carbon release by fire and subsequently influence carbon-climate feedbacks. This presentation will revise the current knowledge on smouldering fires in the Earth system regarding ignition, spread patterns and emissions. It will explain the key differences between shallow and deep fires, and flaming fires.
Energy Systems - Present, Future: Extra Terrestrials, Grades 7, 8, 9,/Science.
ERIC Educational Resources Information Center
National Science Teachers Association, Washington, DC.
The 12 lessons presented in this guide are structured so that they may be integrated into science lessons in 7th-, 8th-, or 9th-grades. Suggestions are made for extension of study. Lessons are approached through classroom role-playing of outer space visitors who seek to understand energy conversion principles used on Earth. Major emphasis is…
Using Gravity Assists in the Earth-moon System as a Gateway to the Solar System
NASA Technical Reports Server (NTRS)
McElrath, Timothy P.; Lantoine, Gregory; Landau, Damon; Grebow, Dan; Strange, Nathan; Wilson, Roby; Sims, Jon
2012-01-01
For spacecraft departing the Earth - Moon system, lunar flybys can significantly increase the hyperbolic escape energy (C3, in km (exp 2) /sec (exp 2) ) for a modest increase in flight time. Within approx 2 months, lunar flybys can produce a C3 of approx 2. Over 4 - 6 months, lunar flybys alone can increase the C3 to approx 4.5, or they can provide for additional periapsis burns to increase the C3 from approx 2 -3 to 10 or more, suitable for planetary missions. A lunar flyby departure can be followed by additional delta -V (such as that efficiently provided by a low thrust system, eg. Solar Electric Propulsion (SEP)) to raise the Earth - relative velocity (at a ratio of more than 2:1) before a subsequent Earth flyby, which redirects that velocity to a more distant target, all within not more than a year. This paper describes the applicability of lunar flybys for different flight times and propulsion systems, and illustrates this with instances of past usage and future possibilities. Examples discussed include ISEE-3, Nozomi, STEREO, 2018 Mars studies (which showed an 8% payload increase), and missions to Near Earth Objects (NEOs). In addition, the options for the achieving the initial lunar flyby are systematically discussed, with a view towards their practical use within a compact launch period. In particular, we show that launches to geosynchronous transfer orbit (GTO) as a secondary payload provide a feasible means of obtaining a lunar flyby for an acceptable cost, even for SEP systems that cannot easily deliver large delta-Vs at periapsis. Taken together, these results comprise a myriad of options for increasing the mission performance, by the efficient use of lunar flybys within an acceptable extension of the flight time.
Using Gravity Assists in the Earth-moon System as a Gateway to the Solar System
NASA Technical Reports Server (NTRS)
McElrath, Tim; Lantoine, Gregory; Landau, Damon; Grebow, Dan; Strange, Nathan; Wilson, Roby; Sims, Jon
2012-01-01
For spacecraft departing the Earth - Moon system, lunar flybys can significantly increase the hype rbolic escape energy (C3, in km 2 /sec 2 ) for a modest increase in flight time. Within 2 months, lunar flybys can produce a C3 of 2. Over 4 - 6 months, lunar flybys alone can increase the C3 to 4.5, or they can provide for additional periapsis burns to increase the C3 from 2 -3 to 10 or more, suitable for planetary missions. A lunar flyby departure can be followed by additional ? -V (such as that efficiently provided by a low thrust system, eg. Solar Electric Propulsion (SEP)) to raise the Earth - relative velocity (at a ratio of more than 2:1) before a subsequent Earth flyby, which redirects that velocity to a more di stant target, all within not much more than a year. This paper describes the applicability of lunar flybys for different flight times and propulsi on systems, and illustrates this with instances of past usage and future possibilities. Examples discussed i nclude ISEE - 3, Nozomi, STEREO, 2018 Mars studies (which showed an 8% payload increase), and missions to Near Earth Objects (NEOs). In addition, the options for the achieving the initial lunar flyby are systematically discussed, with a view towards their p ractical use with in a compact launch period. In particular, we show that launches to geosynchronous transfer orbit (GTO) as a secondary payload provide a feasible means of obtaining a lunar flyby for an acceptable cost, even for SEP systems that cannot ea sily deliver large ? - Vs at periapsis. Taken together, these results comprise a myriad of options for increasing the mission performance, by the efficient use of lunar flybys within an acceptable extension of the flight time.
A Study of Cloud Radiative Forcing and Feedback
NASA Technical Reports Server (NTRS)
Ramanathan, Veerabhadran
2000-01-01
The main objective of the grant proposal was to participate in the CERES (Cloud and Earth's Radiant Energy System) Satellite experiment and perform interdisciplinary investigation of NASA's Earth Observing System (EOS). During the grant period, massive amounts of scientific data from diverse platforms have been accessed, processed and archived for continuing use; several software packages have been developed for integration of different data streams for performing scientific evaluation; extensive validation studies planned have been completed culminating in the development of important algorithms that are being used presently in the operational production of data from the CERES. Contributions to the inter-disciplinary science investigations have been significantly more than originally envisioned. The results of these studies have appeared in several refereed journals and conference proceedings. They are listed at the end of this report.
Information data systems for a global change technology initiative architecture trade study
NASA Technical Reports Server (NTRS)
Murray, Nicholas D.
1991-01-01
The Global Change Technology Initiative (GCTI) was established to develop technology which will enable use of satellite systems of Earth observations on a global scale, enable use of the observations to predictively model Earth's changes, and provide scientists, government, business, and industry with quick access to the resulting information. At LaRC, a GCTI Architecture Trade Study was undertaken to develop and evaluate the architectural implications to meet the requirements of the global change studies and the eventual implementation of a global change system. The output of the trade study are recommended technologies for the GCTI. That portion of the study concerned with the information data system is documented. The information data system for an earth global change modeling system can be very extensive and beyond affordability in terms of today's costs. Therefore, an incremental approach to gaining a system is most likely. An options approach to levels of capability versus needed technologies was developed. The primary drivers of the requirements for the information data system evaluation were the needed science products, the science measurements, the spacecraft orbits, the instruments configurations, and the spacecraft configurations and their attendant architectures. The science products requirements were not studied here; however, some consideration of the product needs were included in the evaluation results. The information data system technology items were identified from the viewpoint of the desirable overall information system characteristics.
View of western portion of the Republic of Panama on Isthmus of Panama
1973-08-30
SL3-27-224 (July-September 1973) --- A vertical view of the western portion of the Republic of Panama on the Isthmus of Panama as photographed from Earth orbit by one of the six lenses of the Itek-furnished S190-A Multispectral Photographic Facility Experiment aboard the Skylab space station. This picture was taken with 2443 infrared color film. The large, clear body of water on the north side of the isthmus is Golfo de los Mosquitos, an extension of the Caribbean Sea. The large, partly cloud-covered body of water on the south side of the isthmus is Golfo de Chiriqui, an extension of the Pacific Ocean. Federal agencies participating with NASA on the EREP project are the Department of Agriculture, Commerce, Interior, the Environmental Protection Agency and the Corps of Engineers. All EREP photography is available to the public through the Department of Interior?s Earth Resources Observation Systems Data Center, Sioux Falls, South Dakota, 57198. Photo credit: NASA
NASA Global Hawk: Project Overview and Future Plans
NASA Technical Reports Server (NTRS)
Naftel, J. Chris
2011-01-01
The National Aeronautics and Space Administration (NASA) Global Hawk Project became operational in 2009 and began support of Earth science in 2010. Thus far, the NASA Global Hawk has completed three Earth science campaigns and preparations are under way for two extensive multi-year campaigns. One of the most desired performance capabilities of the Global Hawk aircraft is very long endurance: the Global Hawk aircraft can remain airborne longer than almost all other jet-powered aircraft currently flying, and longer than all other aircraft available for airborne science use. This paper describes the NASA Global Hawk system, payload accommodations, concept of operations, and the scientific data-gathering campaigns.
Fully autonomous navigation for the NASA cargo transfer vehicle
NASA Technical Reports Server (NTRS)
Wertz, James R.; Skulsky, E. David
1991-01-01
A great deal of attention has been paid to navigation during the close approach (less than or equal to 1 km) phase of spacecraft rendezvous. However, most spacecraft also require a navigation system which provides the necessary accuracy for placing both satellites within the range of the docking sensors. The Microcosm Autonomous Navigation System (MANS) is an on-board system which uses Earth-referenced attitude sensing hardware to provide precision orbit and attitude determination. The system is capable of functioning from LEO to GEO and beyond. Performance depends on the number of available sensors as well as mission geometry; however, extensive simulations have shown that MANS will provide 100 m to 400 m (3(sigma)) position accuracy and 0.03 to 0.07 deg (3(sigma)) attitude accuracy in low Earth orbit. The system is independent of any external source, including GPS. MANS is expected to have a significant impact on ground operations costs, mission definition and design, survivability, and the potential development of very low-cost, fully autonomous spacecraft.
Earth Orbit Raise Design for the Artemis Mission
NASA Technical Reports Server (NTRS)
Wiffen, Gregory J.; Sweetser, Theodore H.
2011-01-01
The Artemis mission is an extension of the Themis mission. The Themis mission1 consisted of five identical spacecraft in varying sized Earth orbits designed to make simultaneous measurements of the Earth's electric and magnetic environment. Themis was designed to observe geomagnetic storms resulting from solar wind's interaction with the Earth's magnetosphere. Themis was meant to answer the age old question of why the Earth's aurora can change rapidly on a global scale. The Themis spacecraft are spin stabilized with 20 meter long electric field booms as well as several shorter magnetometer booms. The goal of the Artemis2 mission extension is to deliver the field and particle measuring capabilities of two of the Themis spacecraft to the vicinity of the Moon. The Artemis mission required transferring two Earth orbiting Themis spacecraft on to two different low energy trans-lunar trajectories ultimately ending in lunar orbit. This paper describes the processes that resulted in successful orbit raise designs for both spacecraft.
New space sensor and mesoscale data analysis
NASA Technical Reports Server (NTRS)
Hickey, John S.
1987-01-01
The developed Earth Science and Application Division (ESAD) system/software provides the research scientist with the following capabilities: an extensive data base management capibility to convert various experiment data types into a standard format; and interactive analysis and display package (AVE80); an interactive imaging/color graphics capability utilizing the Apple III and IBM PC workstations integrated into the ESAD computer system; and local and remote smart-terminal capability which provides color video, graphics, and Laserjet output. Recommendations for updating and enhancing the performance of the ESAD computer system are listed.
Sensor equipment of the German earth scientific airplane program
NASA Technical Reports Server (NTRS)
Seige, P.
1975-01-01
The German airplane program for earth scientific research supports the work of a vast staff of earth scientists from universities and federal agencies. Due to their fields of interest, which are in oceanography, hydrology, geology, ecology, and forestry, five test areas were selected which are spread all over Germany. The sensor package, which was designed in accordance with the requirements of this group of scientists, will be installed in a DO 28 D2 type airplane. The sensor equipment consists of a series of 70-mm cameras having different film/filter combinations, a photogrammetric camera, an infrared radiometer, an 11-channel multispectral line scanner, a LANDSAT-compatible radiometer, and a complex avionic system. Along with the airplane, a truck will be equipped with a set of radiometers and other sensor devices for extensive ground-truth measurement; this also includes a cherry picker.
Human-in-the-Loop Integrated Life Support Systems Ground Testing
NASA Technical Reports Server (NTRS)
Henninger, Donald L.; Marmolejo, Jose A.; Westheimer, David T.
2011-01-01
Human exploration missions beyond low earth orbit will be long duration with abort scenarios of days to months. This necessitates provisioning the crew with all the things they will need to sustain themselves while carrying out mission objectives. Systems engineering and integration is critical to the point where extensive integrated testing of life support systems on the ground is required to identify and mitigate risks. Ground test facilities (human-rated altitude chamber) at the Johnson Space Center are being readied to integrate all the systems for a mission along with a human test crew. The relevant environment will include deep space habitat human accommodations, sealed atmosphere of 8 psi total pressure and 32% oxygen concentration, life support systems (food, air, water), communications, crew accommodations, medical, EVA, tools, etc. Testing periods will approximate those of the expected missions (such as a near Earth asteroid, Earth-Moon L2 or L1, the moon). This type of integrated testing is needed for research and technology development as well as later during the mission design, development, test, and evaluation (DDT&E) phases of an approved program. Testing will evolve to be carried out at the mission level fly the mission on the ground . Mission testing will also serve to inform the public and provide the opportunity for active participation by international partners.
pyGFC - A Python Extension to the C++ Geodesy Foundation Classes
2008-09-01
imperative for a successful emulation of a dynamic MANET as intended. To achieve this objective, the same algorithm and its implementation for...solution has two options: (1) selecting, implementing, and integrating an appropriate algorithm into the tool and in the MANE system, or (2) using an...GFCCoord *estimate_southeast_coords(double, double); double lat; double lon; double alt; private: CEarth *earth; char * cstr
All-optical control of long-lived nuclear spins in rare-earth doped nanoparticles.
Serrano, D; Karlsson, J; Fossati, A; Ferrier, A; Goldner, P
2018-05-29
Nanoscale systems that coherently couple to light and possess spins offer key capabilities for quantum technologies. However, an outstanding challenge is to preserve properties, and especially optical and spin coherence lifetimes, at the nanoscale. Here, we report optically controlled nuclear spins with long coherence lifetimes (T 2 ) in rare-earth-doped nanoparticles. We detect spins echoes and measure a spin coherence lifetime of 2.9 ± 0.3 ms at 5 K under an external magnetic field of 9 mT, a T 2 value comparable to those obtained in bulk rare-earth crystals. Moreover, we achieve spin T 2 extension using all-optical spin dynamical decoupling and observe high fidelity between excitation and echo phases. Rare-earth-doped nanoparticles are thus the only nano-material in which optically controlled spins with millisecond coherence lifetimes have been reported. These results open the way to providing quantum light-atom-spin interfaces with long storage time within hybrid architectures.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Peterson, D.L.; Kaufmann, H.E.
1978-01-01
During July 1977, fifty-one gravity stations were obtained in the Gerlach Extension Known Geothermal Resource Area and vicinity, northwestern Nevada. The gravity observations were made with a Worden gravimeter having a scale factor of about 0.5 milligal per division. No terrain corrections have been applied to these data. The earth tide correction was not used in drift reduction. The Geodetic Reference System 1967 formula (International Association of Geodesy, 1967) was used to compute theoretical gravity. Observed gravity is referenced to a base station in Gerlach, Nevada, having a value based on the Potsdam System of 1930. A density of 2.67more » g per cm/sup 3/ was used in computing the Bouguer anomaly.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Peterson, D.L.; Kaufmann, H.E.
1978-01-01
During July 1977, forty-four gravity stations were obtained in the Fly Ranch Extension Known Geothermal Resource Area and vicinity, northwestern Nevada. The gravity observations were made with a Worden gravimeter having a scale factor of about 0.5 milligal per division. No terrain corrections have been applied to these data. The earth tide correction was not used in drift reduction. The Geodetic Reference System 1967 formula (International Association of Geodesy, 1967) was used to compute theoretical gravity. Observed gravity is referenced to a base station in Gerlach, Nevada, having a value based on the Potsdam System of 1930 (fig. 1). Amore » density of 2.67 g per cm/sup 3/ was used in computing the Bouguer anomaly.« less
NASA Astrophysics Data System (ADS)
Cinquini, L.; Bell, G. M.; Williams, D.; Harney, J.
2012-12-01
The Earth System Grid Federation (ESGF) is a multi-agency, international collaboration that aims at developing state-of-the-art services for the management and access of Earth system data. ESGF is currently used to serve the totality of the model output used for the forthcoming IPCC 5th assessment report on climate change, as well as supporting observational and reanalysis datasets. Also, it is been adopted by several other projects that focus on global, regional and local climate modeling. The ESGF software stack is composed of several modular applications that cover related but disjoint areas of functionality: data publishing, data search and discovery, data access, user management, security, and federation. Overall, the ESGF infrastructure offers a configurable end-to-end solution to the problem of enabling web-based access to large amounts of geospatial data. This talk will present the architectural and configuration options that are available to a data provider leveraging ESGF to serve their data: which services to expose, how to scale to larger data collections, how to establish access control, how to customize the user interface, and others. Additionally, the framework provides extension points that allow each site to plug in custom functionality such as crawling of specific metadata repositories, exposing domain-specific analysis and visualization services, developing custom access clients that interact with the system APIs. These configuration and extension capabilities are based on simple but effective domain-specific object models, that underpin the software applications: the data model, the security model, and the federation model. The ESGF software stack is developed collaboratively by software engineers at many institutions around the world, and is made freely available to the community under an open source license to promote adoption, reuse, inspection and continuous improvement.
Barrat, Jean-Alix; Sillard, Patrick; Starkey, Natalie A.
2018-01-01
The Earth-Moon system likely formed as a result of a collision between two large planetary objects. Debate about their relative masses, the impact energy involved, and the extent of isotopic homogenization continues. We present the results of a high-precision oxygen isotope study of an extensive suite of lunar and terrestrial samples. We demonstrate that lunar rocks and terrestrial basalts show a 3 to 4 ppm (parts per million), statistically resolvable, difference in Δ17O. Taking aubrite meteorites as a candidate impactor material, we show that the giant impact scenario involved nearly complete mixing between the target and impactor. Alternatively, the degree of similarity between the Δ17O values of the impactor and the proto-Earth must have been significantly closer than that between Earth and aubrites. If the Earth-Moon system evolved from an initially highly vaporized and isotopically homogenized state, as indicated by recent dynamical models, then the terrestrial basalt-lunar oxygen isotope difference detected by our study may be a reflection of post–giant impact additions to Earth. On the basis of this assumption, our data indicate that post–giant impact additions to Earth could have contributed between 5 and 30% of Earth’s water, depending on global water estimates. Consequently, our data indicate that the bulk of Earth’s water was accreted before the giant impact and not later, as often proposed. PMID:29600271
Precambrian evolution of the climate system.
Walker, J C
1990-01-01
Climate is an important environmental parameter of the early Earth, likely to have affected the origin and evolution of life, the composition and mineralogy of sedimentary rocks, and stable isotope ratios in sedimentary minerals. There is little observational evidence constraining Precambrian climates. Most of our knowledge is at present theoretical. Factors that must have affected the climate include reduced solar luminosity, enhanced rotation rate of the Earth, an area of land that probably increased with time, and biological evolution, particularly as it affected the composition of the atmosphere and the greenhouse effect. Cloud cover is a major uncertainty about the early Earth. Carbon dioxide and its greenhouse effect are the factors that have been most extensively studied. This paper presents a new examination of the biogeochemical cycles of carbon as they may have changed between an Archean Earth deficient in land, sedimentary rocks, and biological activity, and a Proterozoic Earth much like the modern Earth, but lacking terrestrial life and carbonate-secreting plankton. Results of a numerical simulation of this transition show how increasing biological activity could have drawn down atmospheric carbon dioxide by extracting sedimentary organic carbon from the system. Increasing area of continents could further have drawn down carbon dioxide by encouraging the accumulation of carbonate sediments. An attempt to develop a numerical simulation of the carbon cycles of the Precambrian raises questions about sources and sinks of marine carbon and alkalinity on a world without continents. More information is needed about sea-floor weathering processes.
NASA Astrophysics Data System (ADS)
Connor, C. L.; Prakash, A.
2007-12-01
Alaska's secondary school teachers are increasingly required to provide Earth systems science (ESS) education that integrates student observations of local natural processes related to rapid climate change with geospatial datasets and satellite imagery using Geographic Information Systems (GIS) technology. Such skills are also valued in various employment sectors of the state where job opportunities requiring Earth science and GIS training are increasing. University of Alaska's EDGE (Experiential Discoveries in Geoscience Education) program has provided training and classroom resources for 3 cohorts of inservice Alaska science and math teachers in GIS and Earth Systems Science (2005-2007). Summer workshops include geologic field experiences, GIS instruction, computer equipment and technical support for groups of Alaska high school (HS) and middle school (MS) science teachers each June and their students in August. Since 2005, EDGE has increased Alaska science and math teachers' Earth science content knowledge and developed their GIS and computer skills. In addition, EDGE has guided teachers using a follow-up, fall online course that provided more extensive ESS knowledge linked with classroom standards and provided course content that was directly transferable into their MS and HS science classrooms. EDGE teachers were mentored by University faculty and technical staff as they guided their own students through semester-scale, science fair style projects using geospatial data that was student- collected. EDGE program assessment indicates that all teachers have improved their ESS knowledge, GIS knowledge, and the use of technology in their classrooms. More than 230 middle school students have learned GIS, from EDGE teachers and 50 EDGE secondary students have conducted original research related to landscape change and its impacts on their own communities. Longer-term EDGE goals include improving student performance on the newly implemented (spring 2008) 10th grade, standards-based, High School Qualifying Exam, on recruiting first-generation college students, and on increasing the number of Earth science majors in the University of Alaska system.
NASA Technical Reports Server (NTRS)
Morey-Holton, Emily; Globus, Ruth K.; Kaplansky, Alexander; Durnova, Galina
2005-01-01
The hindlimb unloading rodent model is used extensively to study the response of many physiological systems to certain aspects of space flight, as well as to disuse and recovery from disuse for Earth benefits. This chapter describes the evolution of hindlimb unloading, and is divided into three sections. The first section examines the characteristics of 1064 articles using or reviewing the hindlimb unloading model, published between 1976 and April 1, 2004. The characteristics include number of publications, journals, countries, major physiological systems, method modifications, species, gender, genetic strains and ages of rodents, experiment duration, and countermeasures. The second section provides a comparison of results between space flown and hindlimb unloading animals from the 14-day Cosmos 2044 mission. The final section describes modifications to hindlimb unloading required by different experimental paradigms and a method to protect the tail harness for long duration studies. Hindlimb unloading in rodents has enabled improved understanding of the responses of the musculoskeletal, cardiovascular, immune, renal, neural, metabolic, and reproductive systems to unloading and/or to reloading on Earth with implications for both long-duration human space flight and disuse on Earth.
NASA Technical Reports Server (NTRS)
Niles, Paul B.
2010-01-01
The importance of impact events during the early history of Mars is obvious through a simple examination of the character of the martian surface. This ancient, heavily cratered terrain has been shown to be associated with extensive phyllosilicate deposits. This geologic link could suggest that the extensive phyllosilicate-forming alteration may have occurred during early martian history through impact-induced hydrothermal alteration. However, examination of the oxygen isotopic composition of water on Mars suggests that the extensive phyllosilicate deposits were formed primarily through low temperature (<30 C) interactions, and that high temperature weathering in impact-induced hydrothermal systems have not been a dominant process on Mars. The average oxygen isotopic composition of water on Earth is dictated by the nature of water-rock interactions. If these interactions occur at higher temperatures then the water will contain a higher proportion of 18O, while lower temperature interactions will result in water with a lower proportion of 18O. Water on Earth today contains a higher proportion of 18O because of plate tectonics and hydrothermal interaction at mid-ocean ridges. The oxygen isotopic composition of water on early earth, however, may have been quite different, containing a smaller proportion of 18O suggesting much less hydrothermal interaction. Because there are not yet any direct measurements of the oxygen isotopic composition of water on Mars, it needs to be inferred through examination of carbonates preserved in martian meteorites and the isotopic composition of atmospheric CO2. This can be done because the oxygen incorporated into carbonates and CO2 is easily exchanged with liquid water if it is present. Independently, both measurements provide an estimate for the (Sigma)18O of water on Mars to be near -16%. This composition is consistent with low temperature weathering of the silicate crust, and indicates that impact hydrothermal systems did not play an important role in the early alteration of the planet. However, our understanding of impact-induced hydrothermal systems remains unclear. If most of the water mobilized by an impact event remained at relatively low temperatures (<30deg), low-temperature interactions could predominate in these environments. These conditions would be consistent with the isotopic constraints suggested in this study.
Application of the inner solar system cratering record to the Earth
NASA Technical Reports Server (NTRS)
Barlow, Nadine G.
1990-01-01
The cratering records on the Moon, Mercury, and Mars are studied to provide constraints on: (1) terrestrial conditions prior to about 3.8 Ga, (2) why biology was not extensively established prior to 3.5 Ga, (3) whether impact-induced volcanism can explain some feature of the Cretaceous/Tertiary boundary event, and (4) how common large single-impact events are in the inner solar system. Earth underwent a period of high impact rates and large basin-forming events early in its history, based on the cratering record retained in the Lunar, Mercurian, and Martian highlands. The widespread occurrence of life around 3.5 Ga is linked to the cessation of high impact rates. Impact of a 10-km-diam object into terrestrial oceans could excavate through crustal material and into mantle reservoirs, creating extended basaltic volcanic activity. Scaling laws, coupled with the record retained on Lunar and Martian plains, indicate that between one and seven craters of 90 km diam or greater could have formed on Earth in the past 65 million years.
Rare-Earth Activated Nitride Phosphors: Synthesis, Luminescence and Applications
Xie, Rong-Jun; Hirosaki, Naoto; Li, Yuanqiang; Takeda, Takashi
2010-01-01
Nitridosilicates are structurally built up on three-dimensional SiN4 tetrahedral networks, forming a very interesting class of materials with high thermomechanical properties, hardness, and wide band gap. Traditionally, nitridosilicates are often used as structural materials such as abrasive particles, cutting tools, turbine blade, etc. Recently, the luminescence of rare earth doped nitridosilicates has been extensively studied, and a novel family of luminescent materials has been developed. This paper reviews the synthesis, luminescence and applications of nitridosilicate phosphors, with emphasis on rare earth nitrides in the system of M-Si-Al-O-N (M = Li, Ca, Sr, Ba, La) and their applications in white LEDs. These phosphors exhibit interesting luminescent properties, such as red-shifted excitation and emission, small Stokes shift, small thermal quenching, and high conversion efficiency, enabling them to use as down-conversion luminescent materials in white LEDs with tunable color temperature and high color rendering index.
Impact Crater in Coastal Patagonia
NASA Technical Reports Server (NTRS)
D'Antoni, Hector L; Lasta, Carlos A.; Condon, Estelle (Technical Monitor)
2000-01-01
Impact craters are geological structures attributed to the impact of a meteoroid on the Earth's (or other planet's) surface (Koeberl and Sharpton. 1999). The inner planets of the solar system as well as other bodies such as our moon show extensive meteoroid impacts (Gallant 1964, French 1998). Because of its size and gravity, we may assume that the Earth has been heavily bombarded but weathering and erosion have erased or masked most of these features. In the 1920's, a meteor crater (Mark 1987) was identified in Arizona and to this first finding the identification of a large number of impact structures on Earth followed (Hodge 1994). Shock metamorphic effects are associated with meteorite impact craters. Due to extremely high pressures, shatter cones are produced as well as planar features in quartz and feldspar grains, diaplectic glass and high-pressure mineral phases such as stishovite (French 1998).
Modeling the Round Earth through Diagrams
NASA Astrophysics Data System (ADS)
Padalkar, Shamin; Ramadas, Jayashree
Earlier studies have found that students, including adults, have problems understanding the scientifically accepted model of the Sun-Earth-Moon system and explaining day-to-day astronomical phenomena based on it. We have been examining such problems in the context of recent research on visual-spatial reasoning. Working with middle school students in India, we have developed a pedagogical sequence to build the mental model of the Earth and tried it in three schools for socially and educationally disadvantaged students. This pedagogy was developed on the basis of (1) a reading of current research in imagery and visual-spatial reasoning and (2) students' difficulties identified during the course of pretests and interviews. Visual-spatial tools such as concrete (physical) models, gestures, and diagrams are used extensively in the teaching sequence. The building of a mental model is continually integrated with drawing inferences to understand and explain everyday phenomena. The focus of this article is inferences drawn with diagrams.
Evolving the NASA Near Earth Network for the Next Generation of Human Space Flight
NASA Technical Reports Server (NTRS)
Roberts, Christopher J.; Carter, David L.; Hudiburg, John J.; Tye, Robert N.; Celeste, Peter B.
2014-01-01
The purpose of this paper is to present the planned development and evolution of the NASA Near Earth Network (NEN) launch communications services in support of the next generation of human space flight programs. Following the final space shuttle mission in 2011, the two NEN launch communications stations were decommissioned. Today, NASA is developing the next generation of human space flight systems focused on exploration missions beyond low-earth orbit, and supporting the emerging market for commercial crew and cargo human space flight services. The NEN is leading a major initiative to develop a modern high data rate launch communications ground architecture with support from the Kennedy Space Center Ground Systems Development and Operations Program and in partnership with the U.S. Air Force (USAF) Eastern Range. This initiative, the NEN Launch Communications Stations (LCS) development project, successfully completed its System Requirements Review in November 2013. This paper provides an overview of the LCS project and a summary of its progress. The LCS ground architecture, concept of operations, and driving requirements to support the new heavy-lift Space Launch System and Orion Multi-Purpose Crew Vehicle for Exploration Mission-1 are presented. Finally, potential future extensions to the ground architecture beyond EM-1 are discussed.
Sutton, Stephen R. [University of Chicago, Chicago, Illinois, United States
2017-12-09
Sample-return missions and natural collection processes have provided us with a surprisingly extensive collection of matter from Solar System bodies other than the Earth. These collections include samples from the Moon, Mars, asteroids, interplanetary dust, and, recently, from the Sun (solar wind) and a comet. This presentation will describe some of these materials, how they were collected, and what we have learned from them. Synchrotron radiation analyses of these materials are playing an increasingly valuable role in unraveling the histories and properities of the parent Solar System bodies.
Emmanuel, E S Challaraj; Ananthi, T; Anandkumar, B; Maruthamuthu, S
2012-03-01
In this study, Arthrobacter luteolus, isolated from rare earth environment of Chavara (Quilon district, Kerala, India), were found to produce catechol-type siderophores. The bacterial strain accumulated rare earth elements such as samarium and scandium. The siderophores may play a role in the accumulation of rare earth elements. Catecholate siderophore and low-molecular-weight organic acids were found to be present in experiments with Arthrobacter luteolus. The influence of siderophore on the accumulation of rare earth elements by bacteria has been extensively discussed.
Sensor requirements for Earth and planetary observations
NASA Technical Reports Server (NTRS)
Chahine, Moustafa T.
1990-01-01
Future generations of Earth and planetary remote sensing instruments will require extensive developments of new long-wave and very long-wave infrared detectors. The upcoming NASA Earth Observing System (EOS) will carry a suite of instruments to monitor a wide range of atmospheric and surface parameters with an unprecedented degree of accuracy for a period of 10 to 15 years. These instruments will observe Earth over a wide spectral range extending from the visible to nearly 17 micrometers with a moderate to high spectral and spacial resolution. In addition to expected improvements in communication bandwidth and both ground and on-board computing power, these new sensor systems will need large two-dimensional detector arrays. Such arrays exist for visible wavelengths and, to a lesser extent, for short wavelength infrared systems. The most dramatic need is for new Long Wavelength Infrared (LWIR) and Very Long Wavelength Infrared (VLWIR) detector technologies that are compatible with area array readout devices and can operate in the temperature range supported by long life, low power refrigerators. A scientific need for radiometric and calibration accuracies approaching 1 percent translates into a requirement for detectors with excellent linearity, stability and insensitivity to operating conditions and space radiation. Current examples of the kind of scientific missions these new thermal IR detectors would enhance in the future include instruments for Earth science such as Orbital Volcanological Observations (OVO), Atmospheric Infrared Sounder (AIRS), Moderate Resolution Imaging Spectrometer (MODIS), and Spectroscopy in the Atmosphere using Far Infrared Emission (SAFIRE). Planetary exploration missions such as Cassini also provide examples of instrument concepts that could be enhanced by new IR detector technologies.
Guidelines for the Selection of Near-Earth Thermal Environment Parameters for Spacecraft Design
NASA Technical Reports Server (NTRS)
Anderson, B. J.; Justus, C. G.; Batts, G. W.
2001-01-01
Thermal analysis and design of Earth orbiting systems requires specification of three environmental thermal parameters: the direct solar irradiance, Earth's local albedo, and outgoing longwave radiance (OLR). In the early 1990s data sets from the Earth Radiation Budget Experiment were analyzed on behalf of the Space Station Program to provide an accurate description of these parameters as a function of averaging time along the orbital path. This information, documented in SSP 30425 and, in more generic form in NASA/TM-4527, enabled the specification of the proper thermal parameters for systems of various thermal response time constants. However, working with the engineering community and SSP-30425 and TM-4527 products over a number of years revealed difficulties in interpretation and application of this material. For this reason it was decided to develop this guidelines document to help resolve these issues of practical application. In the process, the data were extensively reprocessed and a new computer code, the Simple Thermal Environment Model (STEM) was developed to simplify the process of selecting the parameters for input into extreme hot and cold thermal analyses and design specifications. In the process, greatly improved values for the cold case OLR values for high inclination orbits were derived. Thermal parameters for satellites in low, medium, and high inclination low-Earth orbit and with various system thermal time constraints are recommended for analysis of extreme hot and cold conditions. Practical information as to the interpretation and application of the information and an introduction to the STEM are included. Complete documentation for STEM is found in the user's manual, in preparation.
Customer premise service study for 30/20 GHz satellite system
NASA Technical Reports Server (NTRS)
Milton, R. T.; Ross, D. P.; Harcar, A. R.; Freedenberg, P.; Schoen, D.
1983-01-01
Satellite systems in which the space segment operates in the 30/20 GHz frequency band are defined and compared as to their potential for providing various types of communications services to customer premises and the economic and technical feasibility of doing so. Technical tasks performed include: market postulation, definition of the ground segment, definition of the space segment, definition of the integrated satellite system, service costs for satellite systems, sensitivity analysis, and critical technology. Based on an analysis of market data, a sufficiently large market for services is projected so as to make the system economically viable. A large market, and hence a high capacity satellite system, is found to be necessary to minimize service costs, i.e., economy of scale is found to hold. The wide bandwidth expected to be available in the 30/20 GHz band, along with frequency reuse which further increases the effective system bandwidth, makes possible the high capacity system. Extensive ground networking is required in most systems to both connect users into the system and to interconnect Earth stations to provide spatial diversity. Earth station spatial diversity is found to be a cost effective means of compensating the large fading encountered in the 30/20 GHz operating band.
NASA Astrophysics Data System (ADS)
Thompson, C. K.; Bingham, A. W.; Hall, J. R.; Alarcon, C.; Plesea, L.; Henderson, M. L.; Levoe, S.
2011-12-01
The State of the Oceans (SOTO) web tool was developed at NASA's Physical Oceanography Distributed Active Archive Center (PO.DAAC) at the Jet Propulsion Laboratory (JPL) as an interactive means for users to visually explore and assess ocean-based geophysical parameters extracted from the latest archived data products. The SOTO system consists of four extensible modules, a data polling tool, a preparation and imaging package, image server software, and the graphical user interface. Together, these components support multi-resolution visualization of swath (Level 2) and gridded Level 3/4) data products as either raster- or vector- based KML layers on Google Earth. These layers are automatically updated periodically throughout the day. Current parameters available include sea surface temperature, chlorophyll concentration, ocean winds, sea surface height anomaly, and sea surface temperature anomaly. SOTO also supports mash-ups, allowing KML feeds from other sources to be overlaid directly onto Google Earth such as hurricane tracks and buoy data. A version of the SOTO software has also been installed at Goddard Space Flight Center (GSFC) to support the Land Atmosphere Near real-time Capability for EOS (LANCE). The State of the Earth (SOTE) has similar functionality to SOTO but supports different data sets, among them the MODIS 250m data product.
A Carbonate Li Isotope Record Through Earth's History
NASA Astrophysics Data System (ADS)
Asael, D.; Kalderon-Asael, B.; Planavsky, N.
2016-12-01
Lithium (Li) isotopes emerge as a powerful geochemical proxy for tracking continental weathering through time. Extensive work on Li fractionation in modern systems has brought to a profound understanding of the modern Li budget as well as to a consensus that marine carbonates faithfully record seawater Li isotope signature. As such record is essential in order to track global-scale changes in weathering processes and intensity through Earth's history, we have generated Li isotope data from marine carbonates from over 40 units, ranging in age from 3.0 Ga to modern. Preliminary results provide evidence for strongly inhibited weathering-mediated clay formation prior to the Paleozoic, which we attribute to the pre-Paleozoic lack of land plants. The initial rise in the Li isotope values is observed during the Ordovician, which is followed by a subsequent drop to background values and then begins the generally increasing trend that is already well reported. These findings are open for interpretation but they still support the view that the emergence of land plants dramatically changed the process of weathering and it seems that biomass has a potentially significant role in mineral breakdown in soils. Li isotopes provide a novel perspective on weathering and the impact on the Earth system of the rise of land plants - one of the most significant transitions in Earth's history.
Bioinspired magnetoreception and navigation using magnetic signatures as waypoints.
Taylor, Brian K
2018-05-15
Diverse taxa use Earth's magnetic field in conjunction with other sensory modalities to accomplish navigation tasks ranging from local homing to long-distance migration across continents and ocean basins. However, despite extensive research, the mechanisms that underlie animal magnetoreception are not clearly understood, and how animals use Earth's magnetic field to navigate is an active area of investigation. Concurrently, Earth's magnetic field offers a signal that engineered systems can leverage for navigation in environments where man-made systems such as GPS are unavailable or unreliable. Using a proxy for Earth's magnetic field, and inspired by migratory animal behavior, this work implements a behavioral strategy that uses combinations of magnetic field properties as rare or unique signatures that mark specific locations. Using a discrete number of these signatures as goal waypoints, the strategy navigates through a closed set of points several times in a variety of environmental conditions, and with various levels of sensor noise. The results from this engineering/quantitative biology approach support existing notions that some animals may use combinations of magnetic properties as navigational markers, and provides insights into features and constraints that would enable navigational success or failure. The findings also offer insights into how autonomous engineered platforms might be designed to leverage the magnetic field as a navigational resource.
STOP for Science! A School-Wide Science Enrichment Program
NASA Astrophysics Data System (ADS)
Slane, P.; Slane, R.; Arcand, K. K.; Lestition, K.; Watzke, M.
2012-08-01
Young students are often natural scientists. They love to poke and prod, and they live to compare and contrast. What is the fastest animal? Where is the tallest mountain on Earth (or in the Solar System)? Where do the colors in a rainbow come from? And why do baseball players choke up on their bats? Educators work hard to harness this energy and enthusiasm in the classroom but, particularly at an early age, science enrichment - exposure outside the formal classroom - is crucial to help expand science awareness and hone science skills. Developed under a grant from NASA's Chandra X-ray Center, "STOP for Science!" is a simple but effective (and extensible) school-wide science enrichment program aimed at raising questions about science topics chosen to capture student interest. Created through the combined efforts of an astrophysicist and an elementary school principal, and strongly recommended by NASA's Earth & Space Science product review, "STOP for Science" combines aesthetic displays of science topics accompanied by level-selected questions and extensive facilitator resources to provide broad exposure to familiar, yet intriguing, science themes.
Evidence for triple-junction rifting focussed on local magmatic centres along Parga Chasma, Venus
NASA Astrophysics Data System (ADS)
Graff, J. R.; Ernst, R. E.; Samson, C.
2018-05-01
Parga Chasma is a discontinuous rift system marking the southern boundary of the Beta-Atla-Themis (BAT) region on Venus. Along a 1500 km section of Parga Chasma, detailed mapping of Magellan Synthetic Aperture Radar images has revealed 5 coronae, 11 local rift zones distinct from a regional extension pattern, and 47 graben-fissure systems with radiating (28), linear (12) and circumferential (7) geometries. The magmatic centres of these graben-fissure systems typically coincide with coronae or large volcanoes, although a few lack any central magmatic or tectonic feature (i.e. are cryptic). Some of the magmatic centres are interpreted as the foci of triple-junction rifting that form the 11 local rift zones. Cross-cutting relationships between graben-fissure systems and local rift faults reveal synchronous formation, implying a genetic association. Additionally, cross-cutting relationships show that local rifting events postdate the regional extension along Parga Chasma, further indicating multiple stages of rifting. Evidence for multiple centres of younger magmatism and local rifting against a background of regional extension provides an explanation for the discontinuous morphology of Parga Chasma. Examination of the Atlantic Rift System (prior to ocean opening) on Earth provides an analogue to the rift morphologies observed on Venus.
NASA Astrophysics Data System (ADS)
Aktuğ, Bahadır; Kılıçoğlu, Ali
2006-07-01
To investigate contemporary neotectonic deformation in İzmir, Western Anatolia and in its neighborhood, a relatively dense Global Positioning System (GPS) monitoring network was established in 2001. Combination of three spatially dense GPS campaigns in 2001, 2003 and 2004 with temporally dense campaigns between 1992 and 2004 resulted in a combined velocity field representing active deformation rate in the region. We computed horizontal and vertical velocity fields with respect to Earth-centered, Earth-fixed ITRF2000, to Eurasia and to Anatolia as well. The rates of principal and shear strains along with rigid-body rotation rates were derived from velocity field. Results show east-west shortening between Karaburun Peninsula and northern part of İzmir Bay together with the extension of İzmir Bay in accordance with general extension regime of Western Anatolia and Eastern Agea. East-west shortening and north-south extension of Karaburun Peninsula are closely related to right-lateral faulting and a clockwise rotation. There exists a block in the middle of the peninsula with a differential motion at a rate of 3-5 ± 1 mm/year and 5-6 ± 1 mm/year to the east and south, respectively. As is in Western Anatolia, north-south extension is dominant in almost all parts of the region despite the fact that they exhibit significantly higher rates in the middle of the peninsula. Extensional rates along Tuzla Fault lying nearly perpendicular to İzmir Bay and in its west are maximum in the region with an extension rate of 300-500 ± 80-100 nanostrain/year and confirm its active state. Extensional rates in other parts of the region are at level of 50-150 nanostrain/year as expected in the other parts of Western Anatolia.
NASA Technical Reports Server (NTRS)
Liebes, S., Jr.
1982-01-01
Half size reproductions are presented of the extensive set of systematic map products generated for the two Mars Viking landing sites from stereo pairs of images radioed back to Earth. The maps span from the immediate foreground to the remote limits of ranging capability, several hundred meters from the spacecraft. The maps are of two kinds - elevation contour and vertical profile. Background and explanatory material important for understanding and utilizing the map collection included covers the Viking Mission, lander locations, lander cameras, the stereo mapping system and input images to this system.
Mining the earth's heat in the basin and range
Sass, John H.
1995-01-01
The Geothermal Program of the U.S. Geological Survey (USGS) is revisiting the Basin and Range Province after a hiatus of over a decade. The Basin and Range is a region of Neogene extension and generally high, but regionally and locally variable heat flow. The northern Basin and Range (Great Basin) has higher mean elevation and more intense Quaternary extension than does the southern Basin and Range, and a somewhat higher average heat flow. Present geothermal electric power generation (500+ MW) is entirely from hydrothermal systems of the Great Basin. The USGS is seeking industrial partners to investigate the potential for new hydrothermal reservoirs and to develop the technology to enhance the productivity of existing reservoirs.
Parquet: Regions of areal plastic dislocations (on Venus)
NASA Technical Reports Server (NTRS)
Sukhanov, A. L.
1986-01-01
The extensive flat elevations of the Northern Hemisphere of Venus are covered with frequently intersecting lines of dislocations, resembling the outline of a giant parquet. In the internal sections of these regions we find grabens and regions of extension, and on the periphery lobe-shaped flow structures. The parquet was formed after the beginning of the formation of the lava plains, but covered by the youngest lava. These structures apparently arose partly because of the dragging of blocks of crust by the asthenospheric flows, and partly in the gravitational sliding of such heated blocks in the partial melting of their base. It is possible that these elevations occupy on Venus the place of the Earth's rift systems.
NASA Technical Reports Server (NTRS)
Lemoine, F. G.; Kenyon, S.C.; Factor, J. K.; Trimmer, R. G.; Pavlis, N. K.; Chinn, D. S.; Cox, C. M.; Klosko, S. M.; Luthcke, S. B.; Torrence, M. H.;
1998-01-01
The NASA Goddard Space Flight Center (GSFC), the National Imagery and Mapping Agency (NIMA), and The Ohio State University (OSU) have collaborated to develop an improved spherical harmonic model of the Earth's gravitational potential to degree 360. The new model, Earth Gravitational Model 1996 (EGM96), incorporates improved surface gravity data, altimeter-derived gravity anomalies from ERS-1 and from the GEOSAT Geodetic Mission (GM), extensive satellite tracking data-including new data from Satellite Laser Ranging (SLR), the Global Postioning System (GPS), NASA's Tracking and Data Relay Satellite System (TDRSS), the French DORIS system, and the US Navy TRANET Doppler tracking system-as well as direct altimeter ranges from TOPEX/POSEIDON (T/P), ERS-1, and GEOSAT. The final solution blends a low-degree combination model to degree 70, a block-diagonal solution from degree 71 to 359, and a quadrature solution at degree 360. The model was used to compute geoid undulations accurate to better than one meter (with the exception of areas void of dense and accurate surface gravity data) and realize WGS84 as a true three-dimensional reference system. Additional results from the EGM96 solution include models of the dynamic ocean topography to degree 20 from T/P and ERS-1 together, and GEOSAT separately, and improved orbit determination for Earth-orbiting satellites.
Human in the Loop Integrated Life Support Systems Ground Testing
NASA Technical Reports Server (NTRS)
Henninger, Donald L.; Marmolejo, Jose A.; Seaman, Calvin H.
2012-01-01
Human exploration missions beyond low earth orbit will be long duration with abort scenarios of days to months. This necessitates provisioning the crew with all the things they will need to sustain themselves while carrying out mission objectives. Systems engineering and integration is critical to the point where extensive integrated testing of life support systems on the ground is required to identify and mitigate risks. Ground test facilities (human-rated altitude chambers) at the Johnson Space Center are being readied to integrate all the systems for a mission along with a human test crew. The relevant environment will include deep space habitat human accommodations, sealed atmosphere capable of 14.7 to 8 psi total pressure and 21 to 32% oxygen concentration, life support systems (food, air, and water), communications, crew accommodations, medical, EVA, tools, etc. Testing periods will approximate those of the expected missions (such as a near Earth asteroid, Earth-Moon L2 or L1, the moon, Mars). This type of integrated testing is needed for research and technology development as well as later during the mission design, development, test, and evaluation (DDT&E) phases of an approved program. Testing will evolve to be carried out at the mission level fly the mission on the ground . Mission testing will also serve to inform the public and provide the opportunity for active participation by international, industrial and academic partners.
Astrobiology and the Possibility of Life on Earth and Elsewhere…
NASA Astrophysics Data System (ADS)
Cottin, Hervé; Kotler, Julia Michelle; Bartik, Kristin; Cleaves, H. James; Cockell, Charles S.; de Vera, Jean-Pierre P.; Ehrenfreund, Pascale; Leuko, Stefan; Ten Kate, Inge Loes; Martins, Zita; Pascal, Robert; Quinn, Richard; Rettberg, Petra; Westall, Frances
2017-07-01
Astrobiology is an interdisciplinary scientific field not only focused on the search of extraterrestrial life, but also on deciphering the key environmental parameters that have enabled the emergence of life on Earth. Understanding these physical and chemical parameters is fundamental knowledge necessary not only for discovering life or signs of life on other planets, but also for understanding our own terrestrial environment. Therefore, astrobiology pushes us to combine different perspectives such as the conditions on the primitive Earth, the physicochemical limits of life, exploration of habitable environments in the Solar System, and the search for signatures of life in exoplanets. Chemists, biologists, geologists, planetologists and astrophysicists are contributing extensively to this interdisciplinary research field. From 2011 to 2014, the European Space Agency (ESA) had the initiative to gather a Topical Team of interdisciplinary scientists focused on astrobiology to review the profound transformations in the field that have occurred since the beginning of the new century. The present paper is an interdisciplinary review of current research in astrobiology, covering the major advances and main outlooks in the field. The following subjects will be reviewed and most recent discoveries will be highlighted: the new understanding of planetary system formation including the specificity of the Earth among the diversity of planets, the origin of water on Earth and its unique combined properties among solvents for the emergence of life, the idea that the Earth could have been habitable during the Hadean Era, the inventory of endogenous and exogenous sources of organic matter and new concepts about how chemistry could evolve towards biological molecules and biological systems. In addition, many new findings show the remarkable potential life has for adaptation and survival in extreme environments. All those results from different fields of science are guiding our perspectives and strategies to look for life in other Solar System objects as well as beyond, in extrasolar worlds.
Thermal control surfaces experiment flight system performance
NASA Technical Reports Server (NTRS)
Wilkes, Donald R.; Hummer, Leigh L.; Zwiener, James M.
1991-01-01
The Thermal Control Surfaces Experiment (TCSE) is the most complex system, other than the LDEF, retrieved after long term space exposure. The TCSE is a microcosm of complex electro-optical payloads being developed and flow by NASA and the DoD including SDI. The objective of TCSE was to determine the effects of the near-Earth orbital environment and the LDEF induced environment on spacecraft thermal control surfaces. The TCSE was a comprehensive experiment that combined in-space measurements with extensive post flight analyses of thermal control surfaces to determine the effects of exposure to the low earth orbit space environment. The TCSE was the first space experiment to measure the optical properties of thermal control surfaces the way they are routinely measured in a lab. The performance of the TCSE confirms that low cost, complex experiment packages can be developed that perform well in space.
A Survey Of Earth-Moon Libration Orbits: Stationkeeping Strategies And Intra-Orbit Transfers
NASA Technical Reports Server (NTRS)
Folta, David; Vaughn, Frank
2004-01-01
Cislunar space is a readily accessible region that may well develop into a prime staging area in the effort to colonize space near Earth or to colonize the Moon. While there have been statements made by various NASA programs regarding placement of resources in orbit about the Earth-Moon Lagrangian locations, there is no survey of the total cost associated with attaining and maintaining these unique orbits in an operational fashion. Transfer trajectories between these orbits required for assembly, servicing, and positioning of these resources have not been extensively investigated. These orbits are dynamically similar to those used for the Sun-Earth missions, but differences in governing gravitational ratios and perturbation sources result in unique characteristics. We implement numerical computations using high fidelity models and linear and nonlinear targeting techniques to compute the various maneuver (Delta)V and temporal costs associated with orbits about each of the Earth-Moon Lagrangian locations (L1, L2, L3, L4, and L5). From a dynamical system standpoint, we speak to the nature of these orbits and their stability. We address the cost of transfers between each pair of Lagrangian locations.
NASA Astrophysics Data System (ADS)
Redfield, Seth; Niraula, Prajwal; Hedges, Christina; Crossfield, Ian; Kreidberg, Laura; Greene, Tom; Rodriguez, Joey; Vanderburg, Andrew; Laughlin, Gregory; Millholland, Sarah; Wang, Songhu; Cochran, William; Livingston, John; Gandolfi, Davide; Guenther, Eike; Fridlund, Malcolm; Korth, Judith
2018-05-01
We propose primary transit observations of three Super-Earth planets in the newly discovered planetary system around a bright, nearby star, GJ 9827. We recently announced the detection of three super-Earth planets in 1:3:5 commensurability, the inner planet, GJ 9827 b having a period of 1.2 days. This is the nearest planetary system that Kepler or K2 has found, at 30 pc, and given its brightness is one of the top systems for follow-up characterization. This system presents a unique opportunity to acquire three planetary transits for the price of one. There are several opportunities in the Spitzer visibility windows to obtain all three transits in a short period of time. We propose 3.6 micron observations of all three Super-Earth transits in a single 18-hour observation window. The proximity to a 1:3:5 resonance is intriguing from a dynamical standpoint as well. Indeed, anomalous transit timing offsets have been measured for planet d in Hubble observations that suffer from partial phase coverage. The short cadence and extended coverage of Spitzer is essential to provide a firm determination of the ephemerides and characterize any transit timing variations. Constraining these orbital parameters is critical for follow-up observations from space and ground-based telescopes. Due to the brightness of the host star, this planetary system is likely to be extensively observed in the years to come. Indeed, our team has acquired observations of the planets orbiting GJ9827 with Hubble in the ultraviolet and infrared. The proposed observations will provide infrared atmospheric measurements and firm orbital characterization which is critical for planning and designing future observations, in particular atmospheric characterization with JWST.
Bioinspired magnetic reception and multimodal sensing.
Taylor, Brian K
2017-08-01
Several animals use Earth's magnetic field in concert with other sensor modes to accomplish navigational tasks ranging from local homing to continental scale migration. However, despite extensive research, animal magnetic reception remains poorly understood. Similarly, the Earth's magnetic field offers a signal that engineered systems can leverage to navigate in environments where man-made positioning systems such as GPS are either unavailable or unreliable. This work uses a behavioral strategy inspired by the migratory behavior of sea turtles to locate a magnetic goal and respond to wind when it is present. Sensing is performed using a number of distributed sensors. Based on existing theoretical biology considerations, data processing is performed using combinations of circles and ellipses to exploit the distributed sensing paradigm. Agent-based simulation results indicate that this approach is capable of using two separate magnetic properties to locate a goal from a variety of initial conditions in both noiseless and noisy sensory environments. The system's ability to locate the goal appears robust to noise at the cost of overall path length.
Run Environment and Data Management for Earth System Models
NASA Astrophysics Data System (ADS)
Widmann, H.; Lautenschlager, M.; Fast, I.; Legutke, S.
2009-04-01
The Integrating Model and Data Infrastructure (IMDI) developed and maintained by the Model and Data Group (M&D) comprises the Standard Compile Environment (SCE) and the Standard Run Environment (SRE). The IMDI software has a modular design, which allows to combine and couple a suite of model components and as well to execute the tasks independently and on various platforms. Furthermore the modular structure enables the extension to new model combinations and new platforms. The SRE presented here enables the configuration and performance of earth system model experiments from model integration up to storage and visualization of data. We focus on recently implemented tasks such as synchronous data base filling, graphical monitoring and automatic generation of meta data in XML forms during run time. As well we address the capability to run experiments in heterogeneous IT environments with different computing systems for model integration, data processing and storage. These features are demonstrated for model configurations and on platforms used in current or upcoming projects, e.g. MILLENNIUM or IPCC AR5.
Review Of Laser Lightcraft Propulsion System
DOE Office of Scientific and Technical Information (OSTI.GOV)
Davis, Eric W.; Mead, Franklin B. Jr
Laser-powered 'Lightcraft' systems that deliver nano-satellites to LEO have been studied for the Air Force Research Laboratory (AFRL). The study was built on the extensive Lightcraft laser propulsion technology already developed by theoretical and experimental work by the AFRL's Propulsion Directorate at Edwards AFB, CA. Here we review the history and engineering-physics of the laser Lightcraft system and its propulsive performance. We will also review the effectiveness and cost of a Lightcraft vehicle powered by a high-energy laser beam. One result of this study is the significant influence of laser wavelength on the power lost during laser beam propagation throughmore » Earth's atmosphere and in space. It was discovered that energy and power losses in the laser beam are extremely sensitive to wavelength for Earth-To-Orbit missions, and this significantly affects the amount of mass that can be placed into orbit for a given maximum amount of radiated power from a ground-based laser.« less
NASA Technical Reports Server (NTRS)
Stephenson, Frank W., Jr.
1988-01-01
The NASA Earth-to-Orbit (ETO) Propulsion Technology Program is dedicated to advancing rocket engine technologies for the development of fully reusable engine systems that will enable space transportation systems to achieve low cost, routine access to space. The program addresses technology advancements in the areas of engine life extension/prediction, performance enhancements, reduced ground operations costs, and in-flight fault tolerant engine operations. The primary objective is to acquire increased knowledge and understanding of rocket engine chemical and physical processes in order to evolve more realistic analytical simulations of engine internal environments, to derive more accurate predictions of steady and unsteady loads, and using improved structural analyses, to more accurately predict component life and performance, and finally to identify and verify more durable advanced design concepts. In addition, efforts were focused on engine diagnostic needs and advances that would allow integrated health monitoring systems to be developed for enhanced maintainability, automated servicing, inspection, and checkout, and ultimately, in-flight fault tolerant engine operations.
Oxygenation history of the Neoproterozoic to early Phanerozoic and the rise of land plants
NASA Astrophysics Data System (ADS)
Wallace, Malcolm W.; Hood, Ashleigh vS.; Shuster, Alice; Greig, Alan; Planavsky, Noah J.; Reed, Christopher P.
2017-05-01
There has been extensive debate about the history of Earth's oxygenation and the role that land plant evolution played in shaping Earth's ocean-atmosphere system. Here we use the rare earth element patterns in marine carbonates to monitor the structure of the marine redox landscape through the rise and diversification of animals and early land plants. In particular, we use the relative abundance of cerium (Ceanom), the only redox-sensitive rare earth element, in well-preserved marine cements and other marine precipitates to track seawater oxygen levels. Our results indicate that there was only a moderate increase in oceanic oxygenation during the Ediacaran (average Cryogenian Ceanom = 1.1, average Ediacaran Ceanom = 0.62), followed by a decrease in oxygen levels during the early Cambrian (average Cryogenian Ceanom = 0.90), with significant ocean anoxia persisting through the early and mid Paleozoic (average Early Cambrian-Early Devonian Ceanom = 0.84). It was not until the Late Devonian that oxygenation levels are comparable to the modern (average of all post-middle Devonian Ceanom = 0.55). Therefore, this work confirms growing evidence that the oxygenation of the Earth was neither unidirectional nor a simple two-stage process. Further, we provide evidence that it was not until the Late Devonian, when large land plants and forests first evolved, that oxygen levels reached those comparable to the modern world. This is recorded with the first modern-like negative Ceanom (values <0.6) occurring at around 380 Ma (Frasnian). This suggests that land plants, rather than animals, are the 'engineers' responsible for the modern fully oxygenated Earth system.
Sprites, elf transients, and positive ground strokes
DOE Office of Scientific and Technical Information (OSTI.GOV)
Boccippio, D.J.; Boldi, R.; Williams, E.R.
1995-08-25
In two summertime mesoscale convective systems (MCSs), mesospheric optical sprite phenomena were often coincident with both large-amplitude positive cloud-to-ground lightning and transient Schumann resonance excitations of the entire Earth-ionosphere cavity. These observations, together with earlier studies of MCS electrification, suggest that sprites are triggered when the rapid removal of large quantities of positive charge from an areally extensive charge layer stresses the mesosphere to dielectric breakdown. 46 refs., 7 figs., 1 tab.
NASA Astrophysics Data System (ADS)
Childs, L. M.; Rogers, L.; Favors, J.; Ruiz, M.
2012-12-01
Through the years, NASA has played a distinct/important/vital role in advancing Earth System Science to meet the challenges of environmental management and policy decision making. Within NASA's Earth Science Division's Applied Sciences' Program, the DEVELOP National Program seeks to extend NASA Earth Science for societal benefit. DEVELOP is a capacity building program providing young professionals and students the opportunity to utilize NASA Earth observations and model output to demonstrate practical applications of those resources to society. Under the guidance of science advisors, DEVELOP teams work in alignment with local, regional, national and international partner organizations to identify the widest array of practical uses for NASA data to enhance related management decisions. The program's structure facilitates a two-fold approach to capacity building by fostering an environment of scientific and professional development opportunities for young professionals and students, while also providing end-user organizations enhanced management and decision making tools for issues impacting their communities. With the competitive nature and growing societal role of science and technology in today's global workplace, DEVELOP is building capacity in the next generation of scientists and leaders by fostering a learning and growing environment where young professionals possess an increased understanding of teamwork, personal development, and scientific/professional development and NASA's Earth Observation System. DEVELOP young professionals are partnered with end user organizations to conduct 10 week feasibility studies that demonstrate the use of NASA Earth science data for enhanced decision making. As a result of the partnership, end user organizations are introduced to NASA Earth Science technologies and capabilities, new methods to augment current practices, hands-on training with practical applications of remote sensing and NASA Earth science, improved remote sensing and geographic information science (GIS) capabilities, and opportunities for networking with the NASA and Earth Science community. By engaging young professionals and end user organizations, DEVELOP strives to uniquely build capacity through the extension of NASA Earth Science outcomes to the public through projects that innovatively use NASA Earth observations to address environmental concerns and impact policy and decision making.
Trade-off analysis of modes of data handling for earth resources (ERS), volume 1
NASA Technical Reports Server (NTRS)
1975-01-01
Data handling requirements are reviewed for earth observation missions along with likely technology advances. Parametric techniques for synthesizing potential systems are developed. Major tasks include: (1) review of the sensors under development and extensions of or improvements in these sensors; (2) development of mission models for missions spanning land, ocean, and atmosphere observations; (3) summary of data handling requirements including the frequency of coverage, timeliness of dissemination, and geographic relationships between points of collection and points of dissemination; (4) review of data routing to establish ways of getting data from the collection point to the user; (5) on-board data processing; (6) communications link; and (7) ground data processing. A detailed synthesis of three specific missions is included.
NASA Technical Reports Server (NTRS)
Erb, R. B.
1974-01-01
The results of the ERTS-1 investigations conducted by the Earth Observations Division at the NASA Lyndon B. Johnson Space Center are summarized in this report, which is an overview of documents detailing individual investigations. Conventional image interpretation and computer-aided classification procedures were the two basic techniques used in analyzing the data for detecting, identifying, locating, and measuring surface features related to earth resources. Data from the ERTS-1 multispectral scanner system were useful for all applications studied, which included agriculture, coastal and estuarine analysis, forestry, range, land use and urban land use, and signature extension. Percentage classification accuracies are cited for the conventional and computer-aided techniques.
Hydrostatic figure of the earth: Theory and results
NASA Technical Reports Server (NTRS)
Khan, M. A.
1973-01-01
The complete development of the mathematical theory of hydrostatic equilibrium for the earth is recounted. Modifications of the first order theory are given along with the subsequent extension to the second order. In addition, the equations are presented which resulted from a revision of the second order theory to suit the new applications and data types of the post-artificial earth satellite era.
Earth satellites: A first look by the United States Navy
NASA Technical Reports Server (NTRS)
Hall, R. C.
1977-01-01
Immediately following World War II, the U.S. Navy considered the possibility of launching an earth satellite for navigational, communications, and meteorological applications. The technical feasibility of the satellite was based on extensions of German V-2 technology.
Imaging spectrometry of the Earth and other solar system bodies
NASA Technical Reports Server (NTRS)
Vane, Gregg
1993-01-01
Imaging spectrometry is a relatively new tool for remote sensing of the Earth and other bodies of the solar system. The technique dates back to the late 1970's and early 1980's. It is a natural extension of the earlier multi-spectral imagers developed for remote sensing that acquire images in a few, usually broad spectral bands. Imaging spectrometers combine aspects of classical spectrometers and imaging systems, making it possible to acquire literally hundreds of images of an object, each image in a separate, narrow spectral band. It is thus possible to perform spectroscopy on a pixel-by-pixel basis with the data acquired with an imaging spectrometer. Two imaging spectrometers have flown in space and several others are planned for future Earth and planetary missions. The French-built Phobos Infrared Spectrometer (ISM) was part of the payload of the Soviet Mars mission in 1988, and the JPL-built Near Infrared Mapping Spectrometer (NIMS) is currently en route to Jupiter aboard the Galileo spacecraft. Several airborne imaging spectrometers have been built in the past decade including the JPL-built Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) which is the only such sensor that covers the full solar reflected portion of the spectrum in narrow, contiguous spectral bands. NASA plans two imaging spectrometers for its Earth Observing System, the Moderate and the High Resolution Imaging Spectrometers (MODIS and HIRIS). A brief overview of the applications of imaging spectrometry to Earth science will be presented to illustrate the value of the tool to remote sensing and indicate the types of measurements that are required. The system design for AVIRS and a planetary imaging spectrometer will be presented to illustrate the engineering considerations and challenges that must be met in building such instruments. Several key sensor technology areas will be discussed in which miniaturization and/or enhanced performance through micromachining and nanofabrication may allow smaller, more robust, and more capable imaging spectrometers to be built in the future.
A Study of the Carbon Cycle Using NASA Observations and the GEOS Model
NASA Technical Reports Server (NTRS)
Pawson, Steven; Gelaro, Ron; Ott, Lesley; Putman, Bill; Chatterjee, Abhishek; Koster, Randy; Lee, Eunjee; Oda, Tom; Weir, Brad; Zeng, Fanwei
2018-01-01
The Goddard Earth Observing System (GEOS) model has been developed in the Global Modeling and Assimilation Office (GMAO) at NASA's Goddard Space Flight Center. From its roots in chemical transport and as a General Circulation Model, the GEOS model has been extended to an Earth System Model based on a modular construction using the Earth System Modeling Framework (ESMF), combining elements developed in house in the GMAO with others that are imported through collaborative research. It is used extensively for research and for product generation, both as a free-running model and as the core of the GMAO's data assimilation system. In recent years, the GMAO's modeling and assimilation efforts have been strongly supported by Piers Sellers, building on both his earlier legacy as an observationally oriented model developer and his post-astronaut career as a dynamic leader into new territory. Piers' long-standing interest in the carbon cycle and the combination of models with observations motivates this presentation, which will focus on the representation of the carbon cycle in the GEOS Earth System Model. Examples will include: (i) the progression from specified land-atmosphere surface fluxes to computations with an interactive model component (Catchment-CN), along with constraints on vegetation distributions using satellite observations; (ii) the use of high-resolution satellite observations to constrain human-generated inputs to the atmosphere; (iii) studies of the consistency of the observed atmospheric carbon dioxide concentrations with those in the model simulations. The presentation will focus on year-to-year variations in elements of the carbon cycle, specifically on how the observations can inform the representation of mechanisms in the model and lead to integrity in global carbon dioxide simulations. Further, applications of the GEOS model to the planning of new carbon-climate observations will be addressed, as an example of the work that was strongly supported by Piers in the last months of his leadership of Earth Science at NASA Goddard.
Land management: data availability and process understanding for global change studies.
Erb, Karl-Heinz; Luyssaert, Sebastiaan; Meyfroidt, Patrick; Pongratz, Julia; Don, Axel; Kloster, Silvia; Kuemmerle, Tobias; Fetzel, Tamara; Fuchs, Richard; Herold, Martin; Haberl, Helmut; Jones, Chris D; Marín-Spiotta, Erika; McCallum, Ian; Robertson, Eddy; Seufert, Verena; Fritz, Steffen; Valade, Aude; Wiltshire, Andrew; Dolman, Albertus J
2017-02-01
In the light of daunting global sustainability challenges such as climate change, biodiversity loss and food security, improving our understanding of the complex dynamics of the Earth system is crucial. However, large knowledge gaps related to the effects of land management persist, in particular those human-induced changes in terrestrial ecosystems that do not result in land-cover conversions. Here, we review the current state of knowledge of ten common land management activities for their biogeochemical and biophysical impacts, the level of process understanding and data availability. Our review shows that ca. one-tenth of the ice-free land surface is under intense human management, half under medium and one-fifth under extensive management. Based on our review, we cluster these ten management activities into three groups: (i) management activities for which data sets are available, and for which a good knowledge base exists (cropland harvest and irrigation); (ii) management activities for which sufficient knowledge on biogeochemical and biophysical effects exists but robust global data sets are lacking (forest harvest, tree species selection, grazing and mowing harvest, N fertilization); and (iii) land management practices with severe data gaps concomitant with an unsatisfactory level of process understanding (crop species selection, artificial wetland drainage, tillage and fire management and crop residue management, an element of crop harvest). Although we identify multiple impediments to progress, we conclude that the current status of process understanding and data availability is sufficient to advance with incorporating management in, for example, Earth system or dynamic vegetation models in order to provide a systematic assessment of their role in the Earth system. This review contributes to a strategic prioritization of research efforts across multiple disciplines, including land system research, ecological research and Earth system modelling. © 2016 John Wiley & Sons Ltd.
Sustainability, collapse and oscillations in a simple World-Earth model
NASA Astrophysics Data System (ADS)
Nitzbon, Jan; Heitzig, Jobst; Parlitz, Ulrich
2017-07-01
The Anthropocene is characterized by close interdependencies between the natural Earth system and the global human society, posing novel challenges to model development. Here we present a conceptual model describing the long-term co-evolution of natural and socio-economic subsystems of Earth. While the climate is represented via a global carbon cycle, we use economic concepts to model socio-metabolic flows of biomass and fossil fuels between nature and society. A well-being-dependent parametrization of fertility and mortality governs human population dynamics. Our analysis focuses on assessing possible asymptotic states of the Earth system for a qualitative understanding of its complex dynamics rather than quantitative predictions. Low dimension and simple equations enable a parameter-space analysis allowing us to identify preconditions of several asymptotic states and hence fates of humanity and planet. These include a sustainable co-evolution of nature and society, a global collapse and everlasting oscillations. We consider different scenarios corresponding to different socio-cultural stages of human history. The necessity of accounting for the ‘human factor’ in Earth system models is highlighted by the finding that carbon stocks during the past centuries evolved opposing to what would ‘naturally’ be expected on a planet without humans. The intensity of biomass use and the contribution of ecosystem services to human well-being are found to be crucial determinants of the asymptotic state in a (pre-industrial) biomass-only scenario without capital accumulation. The capitalistic, fossil-based scenario reveals that trajectories with fundamentally different asymptotic states might still be almost indistinguishable during even a centuries-long transient phase. Given current human population levels, our study also supports the claim that besides reducing the global demand for energy, only the extensive use of renewable energies may pave the way into a sustainable future.
NASA Astrophysics Data System (ADS)
Kennedy, J. H.; Bennett, A. R.; Evans, K. J.; Fyke, J. G.; Vargo, L.; Price, S. F.; Hoffman, M. J.
2016-12-01
Accurate representation of ice sheets and glaciers are essential for robust predictions of arctic climate within Earth System models. Verification and Validation (V&V) is a set of techniques used to quantify the correctness and accuracy of a model, which builds developer/modeler confidence, and can be used to enhance the credibility of the model. Fundamentally, V&V is a continuous process because each model change requires a new round of V&V testing. The Community Ice Sheet Model (CISM) development community is actively developing LIVVkit, the Land Ice Verification and Validation toolkit, which is designed to easily integrate into an ice-sheet model's development workflow (on both personal and high-performance computers) to provide continuous V&V testing.LIVVkit is a robust and extensible python package for V&V, which has components for both software V&V (construction and use) and model V&V (mathematics and physics). The model Verification component is used, for example, to verify model results against community intercomparisons such as ISMIP-HOM. The model validation component is used, for example, to generate a series of diagnostic plots showing the differences between model results against observations for variables such as thickness, surface elevation, basal topography, surface velocity, surface mass balance, etc. Because many different ice-sheet models are under active development, new validation datasets are becoming available, and new methods of analysing these models are actively being researched, LIVVkit includes a framework to easily extend the model V&V analyses by ice-sheet modelers. This allows modelers and developers to develop evaluations of parameters, implement changes, and quickly see how those changes effect the ice-sheet model and earth system model (when coupled). Furthermore, LIVVkit outputs a portable hierarchical website allowing evaluations to be easily shared, published, and analysed throughout the arctic and Earth system communities.
Groundbreaking Mars Sample Return for Science and Human Exploration
NASA Technical Reports Server (NTRS)
Cohen, Barbara; Draper, David; Eppler, Dean; Treiman, Allan
2012-01-01
Partnerships between science and human exploration have recent heritage for the Moon (Lunar Precursor Robotics Program, LPRP) and nearearth objects (Exploration Precursor Robotics Program, xPRP). Both programs spent appreciable time and effort determining measurements needed or desired before human missions to these destinations. These measurements may be crucial to human health or spacecraft design, or may be desired to better optimize systems designs such as spacesuits or operations. Both LPRP and xPRP recommended measurements from orbit, by landed missions and by sample return. LPRP conducted the Lunar Reconnaissance Orbiter (LRO) and Lunar Crater Observation and Sensing Satellite (LCROSS) missions, providing high-resolution visible imagery, surface and subsurface temperatures, global topography, mapping of possible water ice deposits, and the biological effects of radiation [1]. LPRP also initiated a landed mission to provide dust and regolith properties, local lighting conditions, assessment of resources, and demonstration of precision landing [2]. This mission was canceled in 2006 due to funding shortfalls. For the Moon, adequate samples of rocks and regolith were returned by the Apollo and Luna programs to conduct needed investigations. Many near-earth asteroids (NEAs) have been observed from the Earth and several have been more extensively characterized by close-flying missions and landings (NEAR, Hayabusa, Rosetta). The current Joint Robotic Precursor Activity program is considering activities such as partnering with the New Frontiers mission OSIRIS-Rex to visit a NEA and return a sample to the Earth. However, a strong consensus of the NEO User Team within xPRP was that a dedicated mission to the asteroid targeted by humans is required [3], ideally including regolith sample return for more extensive characterization and testing on the Earth.
NASA Technical Reports Server (NTRS)
Sharp, John R.; McConnaughey, Paul K. (Technical Monitor)
2002-01-01
The natural thermal environmental parameters used on the Space Station Program (SSP 30425) were generated by the Space Environmental Effects Branch at NASA's Marshall Space Flight Center (MSFC) utilizing extensive data from the Earth Radiation Budget Experiment (ERBE), a series of satellites which measured low earth orbit (LEO) albedo and outgoing long-wave radiation. Later, this temporal data was presented as a function of averaging times and orbital inclination for use by thermal engineers in NASA Technical Memorandum TM 4527. The data was not presented in a fashion readily usable by thermal engineering modeling tools and required knowledge of the thermal time constants and infrared versus solar spectrum sensitivity of the hardware being analyzed to be used properly. Another TM was recently issued as a guideline for utilizing these environments (NASA/TM-2001-211221) with more insight into the utilization by thermal analysts. This paper gives a top-level overview of the environmental parameters presented in the TM and a study of the effects of implementing these environments on an ongoing MSFC project, the Propulsive Small Expendable Deployer System (ProSEDS), compared to conventional orbital parameters that had been historically used.
Demonstrations of Deployable Systems for Robotic Precursor Missions
NASA Technical Reports Server (NTRS)
Dervan, J.; Johnson, L.; Lockett, T.; Carr, J.; Boyd, D.
2017-01-01
NASA is developing thin-film based, deployable propulsion, power, and communication systems for small spacecraft that serve as enabling technologies for exploration of the solar system. By leveraging recent advancements in thin films, photovoltaics, deployment systems, and miniaturized electronics, new mission-level capabilities will be demonstrated aboard small spacecraft enabling a new generation of frequent, inexpensive, and highly capable robotic precursor missions with goals extensible to future human exploration. Specifically, thin-film technologies are allowing the development and use of solar sails for propulsion, small, lightweight photovoltaics for power, and omnidirectional antennas for communication as demonstrated by recent advances on the Near Earth Asteroid (NEA) Scout and Lightweight Integrated Solar Array and anTenna (LISA-T) projects.
Service Life Extension of the ISS Propulsion System Elements
NASA Technical Reports Server (NTRS)
Kamath, Ulhas; Grant, Gregory; Kuznetsov, Sergei; Shaevich, Sergey; Spencer, Victor
2015-01-01
The International Space Station (ISS) is a result of international collaboration in building a sophisticated laboratory of an unprecedented scale in Low Earth Orbit. After a complex assembly sequence spanning over a decade, some of the early modules launched at the beginning of the program would reach the end of their certified lives, while the newer modules were just being commissioned into operation. To maximize the return on global investments in this one-of-a-kind orbiting platform that was initially conceived for a service life until 2016, it is essential for the cutting edge research on ISS to continue as long as the station can be sustained safely in orbit. ISS Program is assessing individual modules in detail to extend the service life of the ISS to 2024, and possibly to 2028. Without life extension, Functional Cargo Block (known by its Russian acronym as FGB) and the Service Module (SM), two of the early modules on the Russian Segment, would reach the end of their certified lives in 2013 and 2015 respectively. Both FGB and SM are critical for the propulsive function of the ISS. This paper describes the approach used for the service life extension of the FGB propulsion system. Also presented is an overview of the system description along with the process adopted for developing the life test plans based on considerations of system failure modes, fault tolerance and safety provisions. Tests and analyses performed, important findings and life estimates are summarized. Based on the life extension data, FGB propulsion system, in general, is considered ready for a service life until 2028.
NASA Astrophysics Data System (ADS)
Gruszczynska, M.; Rosat, S.; Klos, A.; Bogusz, J.
2017-12-01
In this study, Singular Spectrum Analysis (SSA) along with its multivariate extension MSSA (Multichannel SSA) were used to estimate long-term trend and gravimetric factor at the Chandler wobble frequency from superconducting gravimeter (SG) records. We have used data from seven stations located worldwide and contributing to the International Geodynamics and Earth Tides Service (IGETS). The timespan ranged from 15 to 19 years. Before applying SSA and MSSA, we had removed local tides, atmospheric (ECMWF data), hydrological (MERRA2 products) loadings and non-tidal ocean loading (ECCO2 products) effects. In the first part of analysis, we used the SSA approach in order to estimate the long-term trends from SG observations. We use the technique based on the classical Karhunen-Loève spectral decomposition of time series into long-term trend, oscillations and noise. In the second part, we present the determination of common time-varying pole tide (annual and Chandler wobble) to estimate gravimetric factor from SG time series using the MSSA approach. The presented method takes advantage over traditional methods like Least Squares Estimation by determining common modes of variability which reflect common geophysical field. We adopted a 6-year lag-window as the optimal length to extract common seasonal signals and the Chandler components of the Earth polar motion. The signals characterized by annual and Chandler wobble account for approximately 62% of the total variance of residual SG data. Then, we estimated the amplitude factors and phase lags of Chandler wobble with respect to the IERS (International Earth Rotation and Reference Systems Service) polar motion observations. The resulting gravimetric factors at the Chandler Wobble period are finally compared with previously estimates. A robust estimate of the gravimetric Earth response to the Chandlerian component of the polar motion is required to better constrain the mantle anelasticity at this frequency and hence the attenuation models of the Earth interior.
Cascading elastic perturbation in Japan due to the 2012 M w 8.6 Indian Ocean earthquake.
Delorey, Andrew A; Chao, Kevin; Obara, Kazushige; Johnson, Paul A
2015-10-01
Since the discovery of extensive earthquake triggering occurring in response to the 1992 M w (moment magnitude) 7.3 Landers earthquake, it is now well established that seismic waves from earthquakes can trigger other earthquakes, tremor, slow slip, and pore pressure changes. Our contention is that earthquake triggering is one manifestation of a more widespread elastic disturbance that reveals information about Earth's stress state. Earth's stress state is central to our understanding of both natural and anthropogenic-induced crustal processes. We show that seismic waves from distant earthquakes may perturb stresses and frictional properties on faults and elastic moduli of the crust in cascading fashion. Transient dynamic stresses place crustal material into a metastable state during which the material recovers through a process termed slow dynamics. This observation of widespread, dynamically induced elastic perturbation, including systematic migration of offshore seismicity, strain transients, and velocity transients, presents a new characterization of Earth's elastic system that will advance our understanding of plate tectonics, seismicity, and seismic hazards.
Antarctic Ice Shelf Loss Comes From Underneath
2017-12-08
Calving front of an ice shelf in West Antarctica. The traditional view on ice shelves, the floating extensions of seaward glaciers, has been that they mostly lose ice by shedding icebergs. A new study by NASA and university researchers has found that warm ocean waters melting the ice sheets from underneath account for 55 percent of all ice shelf mass loss in Antarctica. This image was taken during the 2012 Antarctic campaign of NASA's Operation IceBridge, a mission that provided data for the new ice shelf study. Read more: www.nasa.gov/topics/earth/features/earth20130613.html Credit: NASA/GSFC/Jefferson Beck 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
View of Florence, Italy area from Skylab
1973-08-01
SL3-33-156 (July-September 1973) --- A near vertical view of the Florence, Italy area as photographed from Earth orbit by one of the Itek-furnished S190-A Multispectral Photographic Facility Experiment aboard the Skylab space station. The view extends from the Ligurian Sea, an extension of the Mediterranean Sea, across the Apennine Mountains to the Po River Valley. Florence (Firenze) is near the center of the land mass. The mouth of the Arno River is at the center of the coastline. The city of Leghorn (Livorno) is on the coast just south of the Arno River. This picture was taken with type 2443 infrared color film. The S190-A experiment is part of the Skylab Earth Resources Experiments Package. Federal agencies participating with NASA on the EREP project are the Department of Agriculture, Commerce, Interior, the Environmental Protection Agency and the Corps of Engineers. All EREP photography is available to the public through the Department of Interior?s Earth Resources Observations Systems Data Center, Sioux Falls, South Dakota, 57198. Photo credit: NASA
Earth stewardship on rangelands: Coping with ecological, economic, and political marginality
USDA-ARS?s Scientific Manuscript database
Rangelands encompass 30-40 percent of Earth's land surface and support 1-2 billion people. Their predominant use is extensive livestock production by pastoralists and ranchers. But rangelands are characterized by ecological, economic, and political marginality, and higher-value, more intensive land ...
A Brief Summary of the Geomorphic Evidence for an Active Surface Hydrologic Cycle in Mars' Past
NASA Technical Reports Server (NTRS)
Parker, T. J.
2000-01-01
Because Mars is just over half the Earth's diameter (about 6800 km), it does not exhibit global tectonism on a scale comparable to Earth and Venus. But because it is still a large body compared to Mercury and the moon, it has had an atmosphere and climate over the history of the solar system. This is why Mars has been able to retain surfaces produced both through volcanic and climatic processes that are intermediate in age between volcanic surfaces on the moon and Mercury and both types of surfaces on Venus and Earth. For the purposes of this discussion, this has important implications about the origins and evolution of topographic depressions that potentially may have contained lakes. Tectonism is probably the most important process on Earth for producing closed depressions on the continents, and is clearly responsible for maintenance of the ocean basins through geologic time. This is probably also true for depressions in the highland terrains and lowland plains of Venus. On Mars, however, tectonism appears limited to relatively small amounts of regional extension, compression, and vertical motion largely due to crustal loading of the two major volcanic provinces - Tharsis and Elysium Impact craters and large impact basins (including all or parts of the northern plains) are clearly more important sites for potential lake basins on Mars, though they were likely more important on Earth, and Venus as well, during the period of heavy meteorite bombardment throughout the solar system prior to 3.5 Ga. Comparisons of the relative importance of other formative processes on Mars with those on Earth are less obvious, and some may be quite speculative, since our understanding of the early Martian environment is still rather limited. Additional information is contained in the original extended abstract.
NASA Astrophysics Data System (ADS)
Flach, Milan; Mahecha, Miguel; Gans, Fabian; Rodner, Erik; Bodesheim, Paul; Guanche-Garcia, Yanira; Brenning, Alexander; Denzler, Joachim; Reichstein, Markus
2016-04-01
The number of available Earth observations (EOs) is currently substantially increasing. Detecting anomalous patterns in these multivariate time series is an important step in identifying changes in the underlying dynamical system. Likewise, data quality issues might result in anomalous multivariate data constellations and have to be identified before corrupting subsequent analyses. In industrial application a common strategy is to monitor production chains with several sensors coupled to some statistical process control (SPC) algorithm. The basic idea is to raise an alarm when these sensor data depict some anomalous pattern according to the SPC, i.e. the production chain is considered 'out of control'. In fact, the industrial applications are conceptually similar to the on-line monitoring of EOs. However, algorithms used in the context of SPC or process monitoring are rarely considered for supervising multivariate spatio-temporal Earth observations. The objective of this study is to exploit the potential and transferability of SPC concepts to Earth system applications. We compare a range of different algorithms typically applied by SPC systems and evaluate their capability to detect e.g. known extreme events in land surface processes. Specifically two main issues are addressed: (1) identifying the most suitable combination of data pre-processing and detection algorithm for a specific type of event and (2) analyzing the limits of the individual approaches with respect to the magnitude, spatio-temporal size of the event as well as the data's signal to noise ratio. Extensive artificial data sets that represent the typical properties of Earth observations are used in this study. Our results show that the majority of the algorithms used can be considered for the detection of multivariate spatiotemporal events and directly transferred to real Earth observation data as currently assembled in different projects at the European scale, e.g. http://baci-h2020.eu/index.php/ and http://earthsystemdatacube.net/. Known anomalies such as the Russian heatwave are detected as well as anomalies which are not detectable with univariate methods.
NASA Technical Reports Server (NTRS)
Teng, William; Rui, Hualan; Strub, Richard; Vollmer, Bruce
2016-01-01
A long-standing "Digital Divide" in data representation exists between the preferred way of data access by the hydrology community and the common way of data archival by earth science data centers. Typically, in hydrology, earth surface features are expressed as discrete spatial objects (e.g., watersheds), and time-varying data are contained in associated time series. Data in earth science archives, although stored as discrete values (of satellite swath pixels or geographical grids), represent continuous spatial fields, one file per time step. This Divide has been an obstacle, specifically, between the Consortium of Universities for the Advancement of Hydrologic Science, Inc. and NASA earth science data systems. In essence, the way data are archived is conceptually orthogonal to the desired method of access. Our recent work has shown an optimal method of bridging the Divide, by enabling operational access to long-time series (e.g., 36 years of hourly data) of selected NASA datasets. These time series, which we have termed "data rods," are pre-generated or generated on-the-fly. This optimal solution was arrived at after extensive investigations of various approaches, including one based on "data curtains." The on-the-fly generation of data rods uses "data cubes," NASA Giovanni, and parallel processing. The optimal reorganization of NASA earth science data has significantly enhanced the access to and use of the data for the hydrology user community.
Man-machine interface issues in space telerobotics: A JPL research and development program
NASA Technical Reports Server (NTRS)
Bejczy, A. K.
1987-01-01
Technology issues related to the use of robots as man-extension or telerobot systems in space are discussed and exemplified. General considerations are presentd on control and information problems in space teleoperation and on the characteristics of Earth orbital teleoperation. The JPL R and D work in the area of man-machine interface devices and techniques for sensing and computer-based control is briefly summarized. The thrust of this R and D effort is to render space teleoperation efficient and safe through the use of devices and techniques which will permit integrated and task-level (intelligent) two-way control communication between human operator and telerobot machine in Earth orbit. Specific control and information display devices and techniques are discussed and exemplified with development results obtained at JPL in recent years.
Strategic Implications of Human Exploration of Near-Earth Asteroids
NASA Technical Reports Server (NTRS)
Drake, Bret G.
2011-01-01
The current United States Space Policy [1] as articulated by the White House and later confirmed by the Congress [2] calls for [t]he extension of the human presence from low-Earth orbit to other regions of space beyond low-Earth orbit will enable missions to the surface of the Moon and missions to deep space destinations such as near-Earth asteroids and Mars. Human exploration of the Moon and Mars has been the focus of numerous exhaustive studies and planning, but missions to Near-Earth Asteroids (NEAs) has, by comparison, garnered relatively little attention in terms of mission and systems planning. This paper examines the strategic implications of human exploration of NEAs and how they can fit into the overall exploration strategy. This paper specifically addresses how accessible NEAs are in terms of mission duration, technologies required, and overall architecture construct. Example mission architectures utilizing different propulsion technologies such as chemical, nuclear thermal, and solar electric propulsion were formulated to determine resulting figures of merit including number of NEAs accessible, time of flight, mission mass, number of departure windows, and length of the launch windows. These data, in conjunction with what we currently know about these potential exploration targets (or need to know in the future), provide key insights necessary for future mission and strategic planning.
Computer-aided communication satellite system analysis and optimization
NASA Technical Reports Server (NTRS)
Stagl, T. W.; Morgan, N. H.; Morley, R. E.; Singh, J. P.
1973-01-01
The capabilities and limitations of the various published computer programs for fixed/broadcast communication satellite system synthesis and optimization are discussed. A satellite Telecommunication analysis and Modeling Program (STAMP) for costing and sensitivity analysis work in application of communication satellites to educational development is given. The modifications made to STAMP include: extension of the six beam capability to eight; addition of generation of multiple beams from a single reflector system with an array of feeds; an improved system costing to reflect the time value of money, growth in earth terminal population with time, and to account for various measures of system reliability; inclusion of a model for scintillation at microwave frequencies in the communication link loss model; and, an updated technological environment.
NASA Technical Reports Server (NTRS)
Rogers, Aaron; Anderson, Kalle; Mracek, Anna; Zenick, Ray
2004-01-01
With the space industry's increasing focus upon multi-spacecraft formation flight missions, the ability to precisely determine system topology and the orientation of member spacecraft relative to both inertial space and each other is becoming a critical design requirement. Topology determination in satellite systems has traditionally made use of GPS or ground uplink position data for low Earth orbits, or, alternatively, inter-satellite ranging between all formation pairs. While these techniques work, they are not ideal for extension to interplanetary missions or to large fleets of decentralized, mixed-function spacecraft. The Vision-Based Attitude and Formation Determination System (VBAFDS) represents a novel solution to both the navigation and topology determination problems with an integrated approach that combines a miniature star tracker with a suite of robust processing algorithms. By combining a single range measurement with vision data to resolve complete system topology, the VBAFDS design represents a simple, resource-efficient solution that is not constrained to certain Earth orbits or formation geometries. In this paper, analysis and design of the VBAFDS integrated guidance, navigation and control (GN&C) technology will be discussed, including hardware requirements, algorithm development, and simulation results in the context of potential mission applications.
Pongratz, Julia; Dolman, Han; Don, Axel; Erb, Karl-Heinz; Fuchs, Richard; Herold, Martin; Jones, Chris; Kuemmerle, Tobias; Luyssaert, Sebastiaan; Meyfroidt, Patrick; Naudts, Kim
2018-04-01
As the applications of Earth system models (ESMs) move from general climate projections toward questions of mitigation and adaptation, the inclusion of land management practices in these models becomes crucial. We carried out a survey among modeling groups to show an evolution from models able only to deal with land-cover change to more sophisticated approaches that allow also for the partial integration of land management changes. For the longer term a comprehensive land management representation can be anticipated for all major models. To guide the prioritization of implementation, we evaluate ten land management practices-forestry harvest, tree species selection, grazing and mowing harvest, crop harvest, crop species selection, irrigation, wetland drainage, fertilization, tillage, and fire-for (1) their importance on the Earth system, (2) the possibility of implementing them in state-of-the-art ESMs, and (3) availability of required input data. Matching these criteria, we identify "low-hanging fruits" for the inclusion in ESMs, such as basic implementations of crop and forestry harvest and fertilization. We also identify research requirements for specific communities to address the remaining land management practices. Data availability severely hampers modeling the most extensive land management practice, grazing and mowing harvest, and is a limiting factor for a comprehensive implementation of most other practices. Inadequate process understanding hampers even a basic assessment of crop species selection and tillage effects. The need for multiple advanced model structures will be the challenge for a comprehensive implementation of most practices but considerable synergy can be gained using the same structures for different practices. A continuous and closer collaboration of the modeling, Earth observation, and land system science communities is thus required to achieve the inclusion of land management in ESMs. © 2017 John Wiley & Sons Ltd.
Towards an Earth System Knowledge Environment Designed to Promote More Usable Science
NASA Astrophysics Data System (ADS)
Killeen, T. L.
2006-12-01
It is abundantly clear that fundamental decisions about how to manage future human society will need to be informed by quantitative scientific analyses of processes, options, impacts, and responses. In fact, one could argue that the human experience into the foreseeable future will increasingly be tied to the integrating of information, understanding, and experiences to create knowledge and with it solutions to emerging problems as well as opportunities for further progress. This is particularly true for the Geosciences. Our scientific field, and by extension our Union, has a special responsibility for informing policy makers and the public about how the earth system functions and about the relationship between environmental stressors and human activities. In this regard, a greatly improved working interface between natural and social scientists is needed. In this talk, I argue that something like an "Earth System Knowledge Environment" or "Earth System Collaboratory" should be developed using modern information technologies to encapsulate and make accessible existing and emerging interdisciplinary knowledge of particular use to decision makers. Such a "work place" should be open to all and could provide access to observations, models and theories in ways that more easily allow for credible scientific understanding to be translated into policy options at all levels. Examples of fledgling efforts along these lines will be cited in areas such as severe weather impacts and climate change. The challenges involved in creating more usable scientific knowledge are, of course, quite significant and include major issues such as: institutional impediments to interdisciplinary research, the role of proprietary interests, the difficulties involved in working across the natural/social science boundary, and the challenge of developing the kind of human capital needed to effectively close the gap between good science and public policy.
Earthdata 3.0: A Unified Experience and Platform for Earth Science Discovery
NASA Astrophysics Data System (ADS)
Plofchan, P.; McLaughlin, B. D.
2015-12-01
NASA's EOSDIS (Earth Observing System Data and Information System) as a multitude of websites and applications focused on serving the Earth Science community's extensive data needs. With no central user interface, theme, or mechanism for accessing that data, interrelated systems are confusing and potentially disruptive in users' searches for EOSDIS data holdings. In an effort to bring consistency across these systems, an effort was undertaken to develop Earthdata 3.0: a complete information architecture overhaul of the Earthdata website, a significant update to the Earthdata user experience and user interface, and an increased focus on searching across EOSDIS data holdings, including those housed and made available through DAAC websites. As part of this effort, and in a desire to unify the user experience across related websites, the Earthdata User Interface (EUI) was developed. The EUI is a collection of responsive design components and layouts geared toward creating websites and applications within the Earthdata ecosystem. Each component and layout has been designed specifically for Earth science-related projects which eliminates some of the complexities of building a website or application from the ground up. Its adoption will ensure both consistent markup and a unified look and feel for end users, thereby increasing usability and accessibility. Additionally, through the user of a Google Search Appliance, custom Clojure code, and in cooperation with DAACs, Earthdata 3.0 presents a variety of search results upon a user's keyword(s) entry. These results are not just textual links, but also direct links to downloadable datasets, visualizations of datasets and collections of data, and related articles and videos for further research. The end result of the development of the EUI and the enhanced multi-response type search is a consistent and usable platform for Earth scientists and users to navigate and locate data to further their research.
Currents and Flows in Distant Magnetospheres
NASA Technical Reports Server (NTRS)
Kivelson, Margaret Galland
2000-01-01
Space scientists have explored, described, and explained the terrestrial magnetosphere for four decades. Rarely do they point out that the planetary and solar wind parameters controlling the size, shape, and activity of Earth's magnetosphere map out only a small portion of the space of dimensionless parameters that govern magnetospheric properties. With the discovery of Ganymede's magnetosphere, the range of parameters relevant to magnetospheric studies has grown by orders of magnitude. Consider the extremes of Ganymede's and Jupiter's magnetospheres. Jupiter's magnetosphere forms within a plasma flowing at super-Alfvenic speed, whereas Ganymede's forms in a sub-Alfvenic flow. The scale sizes of these magnetospheres, characterized by distances to the magnetopause of order 7x10(exp 6) km and 5x10(exp 3) km, respectively, differ by three orders of magnitude, ranging from 100 to 0.1 times the scale of Earth's magnetosphere. The current systems that control the structure and dynamics of a magnetosphere depend on specific plasma and field properties. Magnetopause currents at Ganymede differ greatly from the forms familiar for Earth and Jupiter, principally because the Mach number of the ambient plasma flow greatly influences the shape of the magnetosphere. A magnetodisk current, present at Jupiter because of its rapid rotation, is absent at Earth and Ganymede. The ring current, extensively investigated at Earth, is probably unimportant at Ganymede because the dynamical variations of the external flow are slow. The ring current is subsumed within the magnetodisk current at Jupiter. This paper describes and contrasts aspects of these and other current systems for the three bodies.
NASA Technical Reports Server (NTRS)
Davis, Randal; Thalman, Nancy
1993-01-01
The University of Colorado's Laboratory for Atmospheric and Space Physics (CU/LASP) along with the Goddard Space Flight Center (GSFC) and the Jet Propulsion Laboratory (JPL) designed, implemented, tested, and demonstrated a prototype of the distributed, hierarchical planning and scheduling system comtemplated for the Earth Observing System (EOS) project. The planning and scheduling prototype made use of existing systems: CU/LASP's Operations and Science Instrument Support Planning and Scheduling (OASIS-PS) software package; GSFC's Request Oriented Scheduling Engine (ROSE); and JPL's Plan Integrated Timeliner 2 (Plan-It-2). Using these tools, four scheduling nodes were implemented and tied together using a new communications protocol for scheduling applications called the Scheduling Applications Interface Language (SAIL). An extensive and realistic scenario of EOS satellite operations was then developed and the prototype scheduling system was tested and demonstrated using the scenario. Two demonstrations of the system were given to NASA personnel and EOS core system (ECS) contractor personnel. A comprehensive volume of lessons learned was generated and a meeting was held with NASA and ECS representatives to review these lessons learned. A paper and presentation on the project's final results was given at the American Institute of Aeronautics and Astronautics Computing in Aerospace 9 conference.
Extending the GI Brokering Suite to Support New Interoperability Specifications
NASA Astrophysics Data System (ADS)
Boldrini, E.; Papeschi, F.; Santoro, M.; Nativi, S.
2014-12-01
The GI brokering suite provides the discovery, access, and semantic Brokers (i.e. GI-cat, GI-axe, GI-sem) that empower a Brokering framework for multi-disciplinary and multi-organizational interoperability. GI suite has been successfully deployed in the framework of several programmes and initiatives, such as European Union funded projects, NSF BCube, and the intergovernmental coordinated effort Global Earth Observation System of Systems (GEOSS). Each GI suite Broker facilitates interoperability for a particular functionality (i.e. discovery, access, semantic extension) among a set of brokered resources published by autonomous providers (e.g. data repositories, web services, semantic assets) and a set of heterogeneous consumers (e.g. client applications, portals, apps). A wide set of data models, encoding formats, and service protocols are already supported by the GI suite, such as the ones defined by international standardizing organizations like OGC and ISO (e.g. WxS, CSW, SWE, GML, netCDF) and by Community specifications (e.g. THREDDS, OpenSearch, OPeNDAP, ESRI APIs). Using GI suite, resources published by a particular Community or organization through their specific technology (e.g. OPeNDAP/netCDF) can be transparently discovered, accessed, and used by different Communities utilizing their preferred tools (e.g. a GIS visualizing WMS layers). Since Information Technology is a moving target, new standards and technologies continuously emerge and are adopted in the Earth Science context too. Therefore, GI Brokering suite was conceived to be flexible and accommodate new interoperability protocols and data models. For example, GI suite has recently added support to well-used specifications, introduced to implement Linked data, Semantic Web and precise community needs. Amongst the others, they included: DCAT: a RDF vocabulary designed to facilitate interoperability between Web data catalogs. CKAN: a data management system for data distribution, particularly used by public administrations. CERIF: used by CRIS (Current Research Information System) instances. HYRAX Server: a scientific dataset publishing component. This presentation will discuss these and other latest GI suite extensions implemented to support new interoperability protocols in use by the Earth Science Communities.
Recent Advances on Sodium-Oxygen Batteries: A Chemical Perspective.
Yadegari, Hossein; Sun, Xueliang
2018-06-19
Releasing greenhouse gases into the atmosphere because of widespread use of fossil fuels by humankind has resulted in raising the earth's temperature during the past few decades. Known as global warming, increasing the earth's temperature may in turn endanger civilization on the earth by starting a cycle of environmental changes including climate change and sea level rise. Therefore, replacing fossil fuels with more sustainable energy resources has been considered as one of the main strategies to tackle the global warming crisis. In this regard, energy saving devices are required to store the energy from sustainable resources like wind and solar when they are available and deliver them on demand. Moreover, developing plug-in electric vehicles (PEVs) as an alternative for internal combustion engines has been extensively pursued, since a major sector of fossil fuels is used for transportation purposes. However, currently available battery systems fail to meet the required demands for energy storage. Alkali metal-O 2 battery systems demonstrate a promising prospect as a high-energy density solution regarding the increasing demand of mankind for energy storage. Combining a metallic negative electrode with a breathing oxygen electrode, a metal-O 2 cell can be considered as a half battery/half fuel cell system. The negative electrode in the metal-O 2 cells operates a conversion reaction rather than intercalation mechanism, which eliminates the need for a host lattice. In addition, the positive electrode material (O 2 ) comes from the ambient air and hence is not stored in the battery. Therefore, the resultant battery systems exhibit the highest theoretical energy density, which is comparable to that of gasoline. Accordingly, an unprecedented amount of research activity was directed toward alkali metal-O 2 batteries in the past decade in response to the need for high-energy storage technology in electric transportation. This extensive research surge has resulted in a rapid expansion of our knowledge about alkali metal-O 2 batteries. The present Account summarizes the most recent findings over the underlying chemistry of all components in Na-O 2 cells as one of the most efficient members of alkali metal-O 2 family.
Challenges for future space power systems
NASA Technical Reports Server (NTRS)
Brandhorst, Henry W., Jr.
1989-01-01
Forecasts of space power needs are presented. The needs fall into three broad categories: survival, self-sufficiency, and industrialization. The cost of delivering payloads to orbital locations and from Low Earth Orbit (LEO) to Mars are determined. Future launch cost reductions are predicted. From these projections the performances necessary for future solar and nuclear space power options are identified. The availability of plentiful cost effective electric power and of low cost access to space are identified as crucial factors in the future extension of human presence in space.
Dawn : a mission in developement for exploration of main belt asteroids Vesta and Ceres
NASA Technical Reports Server (NTRS)
Rayman, Marc D.; Fraschetti, Thomas C.; Russell, Christopher T.; Raymond, Carol A.
2004-01-01
Dawn is in development for a 2006 launch on a mission to explore main belt asteroids in order to yield insights into important questions about the formation and evolution of the solar system. Its objective is to acquire detailed data from orbit around two complementary bodies, Vesta and Ceres, the two most massive asteroids. The project relies on extensive heritage from other deep-space and Earth-orbiting missions, thus permitting the ambitious objectives to be accomplished with an affordable budget.
Wet-based glaciation in Phlegra Montes, Mars.
NASA Astrophysics Data System (ADS)
Gallagher, Colman; Balme, Matt
2016-04-01
Eskers are sinuous landforms composed of sediments deposited from meltwaters in ice-contact glacial conduits. This presentation describes the first definitive identification of eskers on Mars still physically linked with their parent system (1), a Late Amazonian-age glacier (~150 Ma) in Phlegra Montes. Previously described Amazonian-age glaciers on Mars are generally considered to have been dry based, having moved by creep in the absence of subglacial water required for sliding, but our observations indicate significant sub-glacial meltwater routing. The confinement of the Phlegra Montes glacial system to a regionally extensive graben is evidence that the esker formed due to sub-glacial melting in response to an elevated, but spatially restricted, geothermal heat flux rather than climate-induced warming. Now, however, new observations reveal the presence of many assemblages of glacial abrasion forms and associated channels that could be evidence of more widespread wet-based glaciation in Phlegra Montes, including the collapse of several distinct ice domes. This landform assemblage has not been described in other glaciated, mid-latitude regions of the martian northern hemisphere. Moreover, Phlegra Montes are flanked by lowlands displaying evidence of extensive volcanism, including contact between plains lava and piedmont glacial ice. These observations provide a rationale for investigating non-climatic forcing of glacial melting and associated landscape development on Mars, and can build on insights from Earth into the importance of geothermally-induced destabilisation of glaciers as a key amplifier of climate change. (1) Gallagher, C. and Balme, M. (2015). Eskers in a complete, wet-based glacial system in the Phlegra Montes region, Mars, Earth and Planetary Science Letters, 431, 96-109.
NASA Astrophysics Data System (ADS)
Washington, W. M.
2010-12-01
The development of climate and earth system models has been regarded primarily as the making of scientific tools to study the complex nature of the Earth’s climate. These models have a long history starting with very simple physical models based on fundamental physics in the 1960s and over time they have become much more complex with atmospheric, ocean, sea ice, land/vegetation, biogeochemical, glacial and ecological components. The policy use aspects of these models did not start in the 1960s and 1970s as decision making tools but were used to answer fundamental scientific questions such as what happens when the atmospheric carbon dioxide concentration increases or is doubled. They gave insights into the various interactions and were extensively compared with observations. It was realized that models of the earlier time periods could only give first order answers to many of the fundamental policy questions. As societal concerns about climate change rose, the policy questions of anthropogenic climate change became better defined; they were mostly concerned with the climate impacts of increasing greenhouse gases, aerosols, and land cover change. In the late 1980s, the United Nations set up the Intergovernmental Panel on Climate Change to perform assessments of the published literature. Thus, the development of climate and Earth system models became intimately linked to the need to not only improve our scientific understanding but also answering fundamental policy questions. In order to meet this challenge, the models became more complex and realistic so that they could address these policy oriented science questions such as rising sea level. The presentation will discuss the past and future development of global climate and earth system models for science and policy purposes. Also to be discussed is their interactions with economic integrated assessment models, regional and specialized models such as river transport or ecological components. As an example of one development pathway, the NSF/Department of Energy supported Community Climate System and Earth System Models will be featured in the presentation. Computational challenges will also part of the discussion.
Intelligent Systems: Terrestrial Observation and Prediction Using Remote Sensing Data
NASA Technical Reports Server (NTRS)
Coughlan, Joseph C.
2005-01-01
NASA has made science and technology investments to better utilize its large space-borne remote sensing data holdings of the Earth. With the launch of Terra, NASA created a data-rich environment where the challenge is to fully utilize the data collected from EOS however, despite unprecedented amounts of observed data, there is a need for increasing the frequency, resolution, and diversity of observations. Current terrestrial models that use remote sensing data were constructed in a relatively data and compute limited era and do not take full advantage of on-line learning methods and assimilation techniques that can exploit these data. NASA has invested in visualization, data mining and knowledge discovery methods which have facilitated data exploitation, but these methods are insufficient for improving Earth science models that have extensive background knowledge nor do these methods refine understanding of complex processes. Investing in interdisciplinary teams that include computational scientists can lead to new models and systems for online operation and analysis of data that can autonomously improve in prediction skill over time.
Predictive model for ionic liquid extraction solvents for rare earth elements
DOE Office of Scientific and Technical Information (OSTI.GOV)
Grabda, Mariusz; Oleszek, Sylwia; Institute of Environmental Engineering of the Polish Academy of Sciences, ul. M. Sklodowskiej-Curie 34, 41-819, Zabrze
2015-12-31
The purpose of our study was to select the most effective ionic liquid extraction solvents for dysprosium (III) fluoride using a theoretical approach. Conductor-like Screening Model for Real Solvents (COSMO-RS), based on quantum chemistry and the statistical thermodynamics of predefined DyF{sub 3}-ionic liquid systems, was applied to reach the target. Chemical potentials of the salt were predicted in 4,400 different ionic liquids. On the base of these predictions set of ionic liquids’ ions, manifesting significant decrease of the chemical potentials, were selected. Considering the calculated physicochemical properties (hydrophobicity, viscosity) of the ionic liquids containing these specific ions, the most effectivemore » extraction solvents for liquid-liquid extraction of DyF{sub 3} were proposed. The obtained results indicate that the COSMO-RS approach can be applied to quickly screen the affinity of any rare earth element for a large number of ionic liquid systems, before extensive experimental tests.« less
A standard library for modeling satellite orbits on a microcomputer
NASA Astrophysics Data System (ADS)
Beutel, Kenneth L.
1988-03-01
Introductory students of astrodynamics and the space environment are required to have a fundamental understanding of the kinematic behavior of satellite orbits. This thesis develops a standard library that contains the basic formulas for modeling earth orbiting satellites. This library is used as a basis for implementing a satellite motion simulator that can be used to demonstrate orbital phenomena in the classroom. Surveyed are the equations of orbital elements, coordinate systems and analytic formulas, which are made into a standard method for modeling earth orbiting satellites. The standard library is written in the C programming language and is designed to be highly portable between a variety of computer environments. The simulation draws heavily on the standards established by the library to produce a graphics-based orbit simulation program written for the Apple Macintosh computer. The simulation demonstrates the utility of the standard library functions but, because of its extensive use of the Macintosh user interface, is not portable to other operating systems.
The next generation of scenarios for climate change research and assessment.
Moss, Richard H; Edmonds, Jae A; Hibbard, Kathy A; Manning, Martin R; Rose, Steven K; van Vuuren, Detlef P; Carter, Timothy R; Emori, Seita; Kainuma, Mikiko; Kram, Tom; Meehl, Gerald A; Mitchell, John F B; Nakicenovic, Nebojsa; Riahi, Keywan; Smith, Steven J; Stouffer, Ronald J; Thomson, Allison M; Weyant, John P; Wilbanks, Thomas J
2010-02-11
Advances in the science and observation of climate change are providing a clearer understanding of the inherent variability of Earth's climate system and its likely response to human and natural influences. The implications of climate change for the environment and society will depend not only on the response of the Earth system to changes in radiative forcings, but also on how humankind responds through changes in technology, economies, lifestyle and policy. Extensive uncertainties exist in future forcings of and responses to climate change, necessitating the use of scenarios of the future to explore the potential consequences of different response options. To date, such scenarios have not adequately examined crucial possibilities, such as climate change mitigation and adaptation, and have relied on research processes that slowed the exchange of information among physical, biological and social scientists. Here we describe a new process for creating plausible scenarios to investigate some of the most challenging and important questions about climate change confronting the global community.
Marine anoxia and delayed Earth system recovery after the end-Permian extinction
Lau, Kimberly V.; Maher, Kate; Altiner, Demir; Kelley, Brian M.; Kump, Lee R.; Lehrmann, Daniel J.; Silva-Tamayo, Juan Carlos; Weaver, Karrie L.; Yu, Meiyi; Payne, Jonathan L.
2016-01-01
Delayed Earth system recovery following the end-Permian mass extinction is often attributed to severe ocean anoxia. However, the extent and duration of Early Triassic anoxia remains poorly constrained. Here we use paired records of uranium concentrations ([U]) and 238U/235U isotopic compositions (δ238U) of Upper Permian−Upper Triassic marine limestones from China and Turkey to quantify variations in global seafloor redox conditions. We observe abrupt decreases in [U] and δ238U across the end-Permian extinction horizon, from ∼3 ppm and −0.15‰ to ∼0.3 ppm and −0.77‰, followed by a gradual return to preextinction values over the subsequent 5 million years. These trends imply a factor of 100 increase in the extent of seafloor anoxia and suggest the presence of a shallow oxygen minimum zone (OMZ) that inhibited the recovery of benthic animal diversity and marine ecosystem function. We hypothesize that in the Early Triassic oceans—characterized by prolonged shallow anoxia that may have impinged onto continental shelves—global biogeochemical cycles and marine ecosystem structure became more sensitive to variation in the position of the OMZ. Under this hypothesis, the Middle Triassic decline in bottom water anoxia, stabilization of biogeochemical cycles, and diversification of marine animals together reflect the development of a deeper and less extensive OMZ, which regulated Earth system recovery following the end-Permian catastrophe. PMID:26884155
Marine anoxia and delayed Earth system recovery after the end-Permian extinction.
Lau, Kimberly V; Maher, Kate; Altiner, Demir; Kelley, Brian M; Kump, Lee R; Lehrmann, Daniel J; Silva-Tamayo, Juan Carlos; Weaver, Karrie L; Yu, Meiyi; Payne, Jonathan L
2016-03-01
Delayed Earth system recovery following the end-Permian mass extinction is often attributed to severe ocean anoxia. However, the extent and duration of Early Triassic anoxia remains poorly constrained. Here we use paired records of uranium concentrations ([U]) and (238)U/(235)U isotopic compositions (δ(238)U) of Upper Permian-Upper Triassic marine limestones from China and Turkey to quantify variations in global seafloor redox conditions. We observe abrupt decreases in [U] and δ(238)U across the end-Permian extinction horizon, from ∼3 ppm and -0.15‰ to ∼0.3 ppm and -0.77‰, followed by a gradual return to preextinction values over the subsequent 5 million years. These trends imply a factor of 100 increase in the extent of seafloor anoxia and suggest the presence of a shallow oxygen minimum zone (OMZ) that inhibited the recovery of benthic animal diversity and marine ecosystem function. We hypothesize that in the Early Triassic oceans-characterized by prolonged shallow anoxia that may have impinged onto continental shelves-global biogeochemical cycles and marine ecosystem structure became more sensitive to variation in the position of the OMZ. Under this hypothesis, the Middle Triassic decline in bottom water anoxia, stabilization of biogeochemical cycles, and diversification of marine animals together reflect the development of a deeper and less extensive OMZ, which regulated Earth system recovery following the end-Permian catastrophe.
Worldwide seismicity in view of non-extensive statistical physics
NASA Astrophysics Data System (ADS)
Chochlaki, Kaliopi; Vallianatos, Filippos; Michas, George
2014-05-01
In the present work we study the distribution of worldwide shallow seismic events occurred from 1981 to 2011 extracted from the CMT catalog, with magnitude equal or greater than Mw 5.0. Our analysis based on the subdivision of the Earth surface into seismic zones that are homogeneous with regards to seismic activity and orientation of the predominant stress field. To this direction we use the Flinn-Engdahl regionalization (Flinn and Engdahl, 1965), which consists of 50 seismic zones as modified by Lombardi and Marzocchi (2007), where grouped the 50 FE zones into larger tectonically homogeneous ones, utilizing the cumulative moment tensor method. As a result Lombardi and Marzocchi (2007), limit the initial 50 regions to 39 ones, in which we apply the non- extensive statistical physics approach. The non-extensive statistical physics seems to be the most adequate and promising methodological tool for analyzing complex systems, such as the Earth's interior. In this frame, we introduce the q-exponential formulation as the expression of probability distribution function that maximizes the Sq entropy as defined by Tsallis, (1988). In the present work we analyze the interevent time distribution between successive earthquakes by a q-exponential function in each of the seismic zones defined by Lombardi and Marzocchi (2007).confirming the importance of long-range interactions and the existence of a power-law approximation in the distribution of the interevent times. Our findings supports the ideas of universality within the Tsallis approach to describe Earth's seismicity and present strong evidence on temporal clustering of seismic activity in each of the tectonic zones analyzed. Our analysis as applied in worldwide seismicity with magnitude equal or greater than Mw 5.5 and 6.) is presented and the dependence of our result on the cut-off magnitude is discussed. This research has been funded by the European Union (European Social Fund) and Greek national resources under the framework of the "THALES Program: SEISMO FEAR HELLARC" project of the "Education & Lifelong Learning" Operational Programme.
Successful Heliophysical Programs Emphasizing the Relation of Earth and the Sun
NASA Astrophysics Data System (ADS)
Morris, P. A.; Reiff, P.; Sumners, C.; McKay, G. A.
2007-05-01
Heliophysical is defined as the interconnectedness of the entire solar-heliospheric-planetary system. Our goals are to introduce easily accessible programs that introduce the Sun and other solar system processes to the public. The programs emphasize the impact of these processes on Earth and its inhabitants over geological time. These types of programs are important as these topics as generally taught as a secondary concept rather than an integrated approach. Space Weather is an excellent mechanism for integrating Earth and space science. Heliophysics, which includes Space Weather, is traditionally part of space science studies, but most students do not understand the effect of the Sun's atmosphere on Earth or the intense effects energetic particles can have on humans, whether traveling through space or exploring the surfaces of the Moon or Mars. Effects are not only limited to space travel and other planetary surfaces but also include effects on Earth's magnetosphere which, in turn, affect radio transmission, GPS accuracy, and on occasion spacecraft loss and terrestrial power outages. Meteoritic impacts are another topic. Impacts on planetary bodies without strong plate tectonic activities provide ample evidence of their occurrence over geological time. As an analog, impacts have also had an extensive record on Earth, but plate tectonics have been responsible for obliterating most of the evidence. We have developed effective and engaging venues for teaching heliophysics, via the internet, CD-Rom's, museum kiosks, and planetarium shows. We have organized workshops for teachers; "NASA Days" and "Sally Ride Festivals" for students, and "Sun-Earth Day" events for the public. Our goals are both to increase k-16 and public literacy on heliophysical processes and to inspire the next generation to enhance the workforce. We will be offering examples of these programs, as well as distributing CD's and DVD's of some of the creative works.
NASA Astrophysics Data System (ADS)
Chen, S. S.; Curcic, M.
2017-12-01
The need for acurrate and integrated impact forecasts of extreme wind, rain, waves, and storm surge is growing as coastal population and built environment expand worldwide. A key limiting factor in forecasting impacts of extreme weather events associated with tropical cycle and winter storms is fully coupled atmosphere-wave-ocean model interface with explicit momentum and energy exchange. It is not only critical for accurate prediction of storm intensity, but also provides coherent wind, rian, ocean waves and currents forecasts for forcing for storm surge. The Unified Wave INterface (UWIN) has been developed for coupling of the atmosphere-wave-ocean models. UWIN couples the atmosphere, wave, and ocean models using the Earth System Modeling Framework (ESMF). It is a physically based and computationally efficient coupling sytem that is flexible to use in a multi-model system and portable for transition to the next generation global Earth system prediction mdoels. This standardized coupling framework allows researchers to develop and test air-sea coupling parameterizations and coupled data assimilation, and to better facilitate research-to-operation activities. It has been used and extensively tested and verified in regional coupled model forecasts of tropical cycles and winter storms (Chen and Curcic 2016, Curcic et al. 2016, and Judt et al. 2016). We will present 1) an overview of UWIN and its applications in fully coupled atmosphere-wave-ocean model predictions of hurricanes and coastal winter storms, and 2) implenmentation of UWIN in the NASA GMAO GEOS-5.
NASA Technical Reports Server (NTRS)
Alexander, W. M.; Tanner, W. G.; Anz, P. D.; Chen, A. L.
1986-01-01
Extensive studies were conducted concerning the indivdual mass, temporal and positional distribution of micron and submicron lunar ejecta existing in the Earth-Moon gravitational sphere of influence. Initial results show a direct correlation between the position of the Moon, relative to the Earth, and the percentage of lunar ejecta leaving the Moon and intercepting the magnetosphere of the Earth at the magnetopause surface. It is seen that the Lorentz Force dominates all other forces, thus suggesting that submicron dust particles might possibly be magnetically trapped in the well known radiation zones.
The 2nd Generation Real Time Mission Monitor (RTMM) Development
NASA Technical Reports Server (NTRS)
Blakeslee, Richard; Goodman, Michael; Meyer, Paul; Hardin, Danny; Hall, John; He, Yubin; Regner, Kathryn; Conover, Helen; Smith, Tammy; Lu, Jessica;
2009-01-01
The NASA Real Time Mission Monitor (RTMM) is a visualization and information system that fuses multiple Earth science data sources, to enable real time decisionmaking for airborne and ground validation experiments. Developed at the National Aeronautics and Space Administration (NASA) Marshall Space Flight Center, RTMM is a situational awareness, decision-support system that integrates satellite imagery and orbit data, radar and other surface observations (e.g., lightning location network data), airborne navigation and instrument data sets, model output parameters, and other applicable Earth science data sets. The integration and delivery of this information is made possible using data acquisition systems, network communication links, network server resources, and visualizations through the Google Earth virtual globe application. In order to improve the usefulness and efficiency of the RTMM system, capabilities are being developed to allow the end-user to easily configure RTMM applications based on their mission-specific requirements and objectives. This second generation RTMM is being redesigned to take advantage of the Google plug-in capabilities to run multiple applications in a web browser rather than the original single application Google Earth approach. Currently RTMM employs a limited Service Oriented Architecture approach to enable discovery of mission specific resources. We are expanding the RTMM architecture such that it will more effectively utilize the Open Geospatial Consortium Sensor Web Enablement services and other new technology software tools and components. These modifications and extensions will result in a robust, versatile RTMM system that will greatly increase flexibility of the user to choose which science data sets and support applications to view and/or use. The improvements brought about by RTMM 2nd generation system will provide mission planners and airborne scientists with enhanced decision-making tools and capabilities to more efficiently plan, prepare and execute missions, as well as to playback and review past mission data. To paraphrase the old television commercial RTMM doesn t make the airborne science, it makes the airborne science easier.
Regenerative life support systems--why do we need them?
Barta, D J; Henninger, D L
1994-11-01
Human exploration of the solar system will include missions lasting years at a time. Such missions mandate extensive regeneration of life support consumables with efficient utilization of local planetary resources. As mission durations extend beyond one or two years, regenerable human life support systems which supply food and recycle air, water, and wastes become feasible; resupply of large volumes and masses of food, water, and atmospheric gases become unrealistic. Additionally, reduced dependency on resupply or self sufficiency can be an added benefit to human crews in hostile environments far from the security of Earth. Comparisons of resupply and regeneration will be discussed along with possible scenarios for developing and implementing human life support systems on the Moon and Mars.
A general scientific information system to support the study of climate-related data
NASA Technical Reports Server (NTRS)
Treinish, L. A.
1984-01-01
The development and use of NASA's Pilot Climate Data System (PCDS) are discussed. The PCDS is used as a focal point for managing and providing access to a large collection of actively used data for the Earth, ocean and atmospheric sciences. The PCDS provides uniform data catalogs, inventories, and access methods for selected NASA and non-NASA data sets. Scientific users can preview the data sets using graphical and statistical methods. The system has evolved from its original purpose as a climate data base management system in response to a national climate program, into an extensive package of capabilities to support many types of data sets from both spaceborne and surface based measurements with flexible data selection and analysis functions.
The Penn State ORSER system for processing and analyzing ERTS and other MSS data
NASA Technical Reports Server (NTRS)
Mcmurtry, G. J.; Petersen, G. W. (Principal Investigator); Borden, F. Y.; Weeden, H. A.
1974-01-01
The author has identified the following significant results. The office for Remote Sensing of Earth Resources (ORSER) of the Space Science and Engineering Laboratory at the Pennsylvania State University has developed an extensive operational system for processing and analyzing ERTS-1 and similar multispectral data. The ORSER system was developed for use by a wide variety of researchers working in remote sensing. Both photointerpretive techniques and automatic computer processing methods have been developed and used, separately and in a combined approach. A remote Job Entry system permits use of an IBM 370/168 computer from any compatible remote terminal, including equipment tied in by long distance telephone connections. An elementary cost analysis has been prepared for the processing of ERTS data.
NASA Technical Reports Server (NTRS)
McCain, Harry G. (Technical Monitor)
2000-01-01
The National Oceanic and Atmospheric Administration (NOAA) and the National Aeronautics and Space Administration (NASA) have jointly developed a valuable series of polar-orbiting Earth environmental observation satellites since 1978. These satellites provide global data to NOAA's short- and long-range weather forecasting systems. The system consists of two polar-orbiting satellites known as the Advanced Television Infrared Observation Satellites (TIROS-N) (ATN). Operating as a pair, these satellites ensure that environmental data, for any region of the Earth, is no more than six hours old. These polar-orbiting satellites have not only provided cost-effective data for very immediate and real needs but also for extensive climate and research programs. The weather data (including images seen on television news programs) has afforded both convenience and safety to viewers throughout the world. The satellites also support the SARSAT (Search and Rescue Satellite Aided Tracking) part of the COSPAS-SARSAT constellation. Russia provides the COSPAS (Russian for Space Systems for the Search of Vessels in Distress) satellites. The international COSPAS-SARSAT system provides for the detection and location of emergency beacons for ships, aircraft, and people in distress and has contributed to the saving of more than 10,000 lives since its inception in 1982.
Non-Fermi liquids in oxide heterostructures
NASA Astrophysics Data System (ADS)
Stemmer, Susanne; Allen, S. James
2018-06-01
Understanding the anomalous transport properties of strongly correlated materials is one of the most formidable challenges in condensed matter physics. For example, one encounters metal-insulator transitions, deviations from Landau Fermi liquid behavior, longitudinal and Hall scattering rate separation, a pseudogap phase, and bad metal behavior. These properties have been studied extensively in bulk materials, such as the unconventional superconductors and heavy fermion systems. Oxide heterostructures have recently emerged as new platforms to probe, control, and understand strong correlation phenomena. This article focuses on unconventional transport phenomena in oxide thin film systems. We use specific systems as examples, namely charge carriers in SrTiO3 layers and interfaces with SrTiO3, and strained rare earth nickelate thin films. While doped SrTiO3 layers appear to be a well behaved, though complex, electron gas or Fermi liquid, the rare earth nickelates are a highly correlated electron system that may be classified as a non-Fermi liquid. We discuss insights into the underlying physics that can be gained from studying the emergence of non-Fermi liquid behavior as a function of the heterostructure parameters. We also discuss the role of lattice symmetry and disorder in phenomena such as metal-insulator transitions in strongly correlated heterostructures.
The Oxford Companion to the Earth
NASA Astrophysics Data System (ADS)
Hancock, Paul L.
2001-06-01
Here is a wealth of information on planet Earth, ranging from the heights of the ionsphere down to the red-hot molten core. Written by some 200 expert contributors, and illustrated with over 600 pictures, including 16 pages of color plates, The Oxford Companion to the Earth offers 900 alphabetically arranged entries that cover everything from deserts and wetlands to mountains, caves, glaciers, and coral reefs. There are articles on natural phenomena such as tornadoes and tsunamis, volcanoes and earthquakes, jet streams and weather fronts; on the history of Earth, including the origin of life, Burgess Shale fauna, dinosaurs, and the Ice Ages; on key figures, such as Agassiz, Cuvier, Darwin, and Lamarck; and on such important ecological concerns as acid rain, the ozone layer, industrial waste disposal, and the greenhouse effect. The Companion also examines the great sources of wealth to be found in the Earth, from coal and oil to gold, silver, and diamonds, and many curious land formations, from sinkholes and fiords to yardangs and quicksand. There are brief entries on rock types, from amber to travertine, and extensive essays on cutting-edge aspects of the earth sciences, such as seismology and marine geology. The Companion includes extensive cross-references, suggested further reading, an index, and many useful appendices, with a geological timescale, facts and figures about the Earth, and a table of chemical elements. The Oxford Companion to the Earth is a unique reference work, offering unrivaled coverage of our home planet. Generously illustrated and vividly written, it is a treasure house of information for all lovers of natural history, geology, and ecology, whether professional or amateur.
Vuković, Gordana; Aničić Urošević, Mira; Pergal, Miodrag; Janković, Milan; Goryainova, Zoya; Tomašević, Milica; Popović, Aleksandar
2015-12-01
In areas with moderate to continental climates, emissions from residential heating system lead to the winter air pollution peaks. The EU legislation requires only the monitoring of airborne concentrations of particulate matter, As, Cd, Hg, Ni, and B[a]P. Transition metals and rare earth elements (REEs) have also arisen questions about their detrimental health effects. In that sense, this study examined the level of extensive set of air pollutants: 16 polycyclic aromatic hydrocarbons (PAHs), and 41 major elements, trace elements, and REEs using Sphagnum girgensohnii moss bag technique. During the winter of 2013/2014, the moss bags were exposed across Belgrade (Serbia) to study the influence of residential heating system to the overall air quality. The study was set as an extension to our previous survey during the summer, i.e., non-heating season. Markedly higher concentrations of all PAHs, Sb, Cu, V, Ni, and Zn were observed in the exposed moss in comparison to the initial values. The patterns of the moss REE concentrations normalized to North American Shale Composite and Post-Archean Australian Shales were identical across the study area but enhanced by anthropogenic activities. The results clearly demonstrate the seasonal variations in the moss enrichment of the air pollutants. Moreover, the results point out a need for monitoring of air quality during the whole year, and also of various pollutants, not only those regulated by the EU Directive.
Jupiter and the Voyager mission
Soderblom, L.; Spall, Henry
1980-01-01
In 1977, the United States launched two unmanned Voyager spacecraft that were to take part in an extensive reconnaissance of the outer planets over a 12-year period visiting the environs of Jupiter, Saturn, Uranus, and Neptune. Their first encounter was with the complex Jupiter planetary system 400 million miles away. Sweeping by Jupiter and its five moons in 1979, the two spacecraft have sent back to Earth an enormous amount of data that will prove to be vital in understanding our solar system. Voyager 1 is scheduled to fly past Saturn on November 13 of this year; Voyager 2, in August of the following year.
Closest rocky exoplanet confirmed on This Week @NASA – July 31, 2015
2015-07-31
NASA’s Spitzer Space Telescope has helped astronomers confirm the discovery of the nearest rocky planet outside our solar system. The planet, called HD 219134b, is a bit larger than Earth and located a mere 21 light-years away in the Cassiopeia constellation, near the North Star. While HD 219134b orbits too close to its star to sustain life, it is the closest exoplanet to Earth to be detected transiting, or crossing in front of, its star – which makes it perfect for extensive scientific research. The results of this discovery are the subject of a study accepted for publication in the journal Astronomy & Astrophysics. Also, Exoplanet found far from its central star, Orion fairing separation tests, NEEMO 20 mission, California’s “rain debt” and Unmanned Air Traffic Management!
LACIE performance predictor final operational capability program description, volume 1
NASA Technical Reports Server (NTRS)
1976-01-01
The program EPHEMS computes the orbital parameters for up to two vehicles orbiting the earth for up to 549 days. The data represents a continuous swath about the earth, producing tables which can be used to determine when and if certain land segments will be covered. The program GRID processes NASA's climatology tape to obtain the weather indices along with associated latitudes and longitudes. The program LUMP takes substrata historical data and sample segment ID, crop window, crop window error and statistical data, checks for valid input parameters and generates the segment ID file, crop window file and the substrata historical file. Finally, the System Error Executive (SEE) Program checks YES error and truth data, CAMS error data, and signature extension data for validity and missing elements. A message is printed for each error found.
NASA Technical Reports Server (NTRS)
Roberts, Barry C.; Batts, Wade
1997-01-01
The National Aeronautics and Space Administration (NASA) designated Marshall Space Flight Center (MSFC) the center of excellence for space transportation. The Aerospace Environments and Effects (AEE) team of the Electromagnetics and Aerospace Environments Branch (EL23) in the Systems Analysis and Integration Laboratory at MSFC, supports the center of excellence designation by providing near-Earth space, deep space, planetary, and terrestrial environments expertise to projects as required. The Terrestrial Environment (TE) group within the AEE team maintains an extensive TE data base. Statistics and models derived from this data are applied to the design and development of new aerospace vehicles, as well as performance enhancement of operational vehicles such as the Space Shuttle. The TE is defined as the Earth's atmospheric environment extending from the surface to orbital insertion altitudes (approximately 90 km).
NASA Technical Reports Server (NTRS)
West, John L.
2008-01-01
Here-to-fore, sailcraft mission and system studies have focused on sailcraft applications in support of NASA's science missions and, in a few studies, on the needs of other federal agencies such as the National Oceanic and Atmospheric Administration (NOAA) and Department of Defense (DoD). These studies have identified numerous promising applications for solar sails, leading NASA to support proposal efforts for three NASA New Millennium Program (NMP) flight demonstration opportunities (the Space Technology-5, -7, and -9 opportunities) as well as an extensive three-year ground development program in FY 2003-2005 sponsored by the NASA In-Space Propulsion Technology (ISPT) Program. What has not been done to date, however, is to investigate how the technology might also benefit the nation's (and NASA's) emerging interest in the Human Exploration Initiative (HEI). This paper reports on the first effort to address this shortfall in mission applications studies in support of HEI: the use of solar-sail-propelled Lunar Polesitter spacecraft which make use of the natural properties of the Earth-Moon L2 point and solar sail propulsion to enable their positioning near the Lunar poles to serve as communications relay stations. Suitably positioned, such spacecraft enable continuous communications to and from the Earth from any point on the lunar far side. The paper shows that a viable sailcraft system design exists permitting station-keeping of a Lunar Polesitter relay station at 40 Lunar radii from the Moon in the anti-Earth direction, displaced 6-8 Lunar radii below the Earth- Moon plane.
Human Exploration and Development of Space: Strategic Plan
NASA Technical Reports Server (NTRS)
Branscome, Darrell (Editor); Allen, Marc (Editor); Bihner, William (Editor); Cooke, Douglas (Editor); Craig, Mark (Editor); Crouch, Matthew (Editor); Crouch, Roger (Editor); Flaherty, Chris (Editor); Haynes, Norman (Editor); Horowitz, Steven (Editor)
2001-01-01
In order to make possible the permanent extension of human presence beyond the bounds of Earth and enable historic improvements in our understanding of our solar system and the universe, and the quality of life, NASA must: (1) Undertake, in partnership with the scientific community, sustained international explorations throughout the inner solar system by integrated human/robotic expeditions; (2) Achieve breakthrough discoveries and technology developments through basic, applied, and commercial research in the unique venue of space--exploiting characteristics such as microgravity, vacuum, radiation, and location; (3) Establish safe and routine access to space in support of permanent commercial human operations in low-Earth orbit and ongoing exploration activities at one or more sites beyond Earth orbit; (4) Engage the private sector in the commercial development of space and enable the creation of new space industries generating new wealth for the US economy; and (5) Communicate the excitement and importance of the discovery of new worlds and the profound insights we will gain into the origins of life and the universe. In order to guide planning, the Human Exploration and Development of Space (HEDS) Enterprise has identified some potential future targets and goals (e.g. 'Design Reference Points') beginning with the near-term and extending to the far-term and beyond.
Federal Register 2010, 2011, 2012, 2013, 2014
2011-08-10
... Previously Approved Information Collection'' for volunteer workers (73 FR 62949). In accordance with the... request an extension for currently approved information collection, Volunteer Program-Earth Team. This..., for the Volunteer Interest and Placement Summary form and the Time Sheet form. The collected...
Extensive Air Showers in the Classroom
ERIC Educational Resources Information Center
Badala, A.; Blanco, F.; La Rocca, P.; Pappalardo, G. S.; Pulvirenti, A.; Riggi, F.
2007-01-01
The basic properties of extensive air showers of particles produced in the interaction of a high-energy primary cosmic ray in the Earth's atmosphere are discussed in the context of educational cosmic ray projects involving undergraduate students and high-school teams. Simulation results produced by an air shower development code were made…
DOE Office of Scientific and Technical Information (OSTI.GOV)
Sanromá, E.; Pallé, E.; López, R.
2014-01-01
Ongoing searches for exoplanetary systems have revealed a wealth of planets with diverse physical properties. Planets even smaller than the Earth have already been detected and the efforts of future missions are aimed at the discovery, and perhaps characterization, of small rocky exoplanets within the habitable zone of their stars. Clearly, what we know about our planet will be our guideline for the characterization of such planets. However, the Earth has been inhabited for at least 3.8 Gyr and its appearance has changed with time. Here, we have studied the Earth during the Archean eon, 3.0 Gyr ago. At thatmore » time, one of the more widespread life forms on the planet was purple bacteria. These bacteria are photosynthetic microorganisms and can inhabit both aquatic and terrestrial environments. Here, we use a radiative transfer model to simulate the visible and near-infrared radiation reflected by our planet, taking into account several scenarios regarding the possible distribution of purple bacteria over continents and oceans. We find that purple bacteria have a reflectance spectrum that has a strong reflectivity increase, similar to the red edge of leafy plants, although shifted redward. This feature produces a detectable signal in the disk-averaged spectra of our planet, depending on cloud amount and purple bacteria concentration/distribution. We conclude that by using multi-color photometric observations, it is possible to distinguish between an Archean Earth in which purple bacteria inhabit vast extensions of the planet and a present-day Earth with continents covered by deserts, vegetation, or microbial mats.« less
Earth observations from space: History, promise, and reality. Executive summary
NASA Technical Reports Server (NTRS)
1995-01-01
In this report the Committee on Earth Studies (CES), a standing committee of the Space Studies Board (SSB) within the National Research Council (NRC), reviews the recent history (nominally from 1981 to 1995) of the U.S. earth observations programs that serve civilian needs. The principal observations programs examined are those of NASA and the National Oceanic and Atmospheric Administration (NOAA). The Air Force' s Defense Meteorological Satellite Program (DMSP) is discussed, but only from the perspective of its relationship to civil needs and the planned merger with the NOAA polar-orbiting system. The report also reviews the interfaces between the earth observations satellite programs and the major national and international environmental monitoring and research programs. The monitoring and research programs discussed are the U.S. Global Change Research Program (USGCRP), the International Geosphere-Biosphere Program (IGBP), the World Climate Research Program (WCRP), related international scientific campaigns, and operational programs for the sharing and application of environmental data. The purpose of this report is to provide a broad historical review and commentary based on the views of the CES members, with particular emphasis on tracing the lengthy record of advisory committee recommendations. Any individual topic could be the subject of an extended report in its own right. Indeed, extensive further reviews are already under way to that end. If the CES has succeeded in the task it has undertaken. This report will serve as a useful starting point for any such more intensive study. The report is divided into eight chapters: ( I ) an introduction, (2) the evolution of the MTPE, (3) its relationship to the USGCRP, (4) applications of earth observations data, (5) the role that smaller satellites can play in research and operational remote sensing, (6) earth system modeling and information systems, (7) a number of associated activities that contribute to the MTPE and the USGCRP, and (8) organizational issues in the conduct of civil earth observations programs. Following the body of the report is a series of appendixes: after a list of acronyms and abbreviations and collected short biographies of CES members, six brief tutorials discuss several scientific topics important to the science and applications of earth observations. Highlights from the eight chapters follow.
NASA Astrophysics Data System (ADS)
Shaffer, Gary; Fernández Villanueva, Esteban; Rondanelli, Roberto; Olaf Pepke Pedersen, Jens; Malskær Olsen, Steffen; Huber, Matthew
2017-11-01
Geological records reveal a number of ancient, large and rapid negative excursions of the carbon-13 isotope. Such excursions can only be explained by massive injections of depleted carbon to the Earth system over a short duration. These injections may have forced strong global warming events, sometimes accompanied by mass extinctions such as the Triassic-Jurassic and end-Permian extinctions 201 and 252 million years ago, respectively. In many cases, evidence points to methane as the dominant form of injected carbon, whether as thermogenic methane formed by magma intrusions through overlying carbon-rich sediment or from warming-induced dissociation of methane hydrate, a solid compound of methane and water found in ocean sediments. As a consequence of the ubiquity and importance of methane in major Earth events, Earth system models for addressing such events should include a comprehensive treatment of methane cycling but such a treatment has often been lacking. Here we implement methane cycling in the Danish Center for Earth System Science (DCESS) model, a simplified but well-tested Earth system model of intermediate complexity. We use a generic methane input function that allows variation in input type, size, timescale and ocean-atmosphere partition. To be able to treat such massive inputs more correctly, we extend the model to deal with ocean suboxic/anoxic conditions and with radiative forcing and methane lifetimes appropriate for high atmospheric methane concentrations. With this new model version, we carried out an extensive set of simulations for methane inputs of various sizes, timescales and ocean-atmosphere partitions to probe model behavior. We find that larger methane inputs over shorter timescales with more methane dissolving in the ocean lead to ever-increasing ocean anoxia with consequences for ocean life and global carbon cycling. Greater methane input directly to the atmosphere leads to more warming and, for example, greater carbon dioxide release from land soils. Analysis of synthetic sediment cores from the simulations provides guidelines for the interpretation of real sediment cores spanning the warming events. With this improved DCESS model version and paleo-reconstructions, we are now better armed to gauge the amounts, types, timescales and locations of methane injections driving specific, observed deep-time, global warming events.
VLBI: A Fascinating Technique for Geodesy and Astrometry
NASA Technical Reports Server (NTRS)
Schuh, H.; Behrend, Dirk
2012-01-01
Since the 1970s Very Long Baseline Interferometry (VLBI) has proven to be a primary space-geodetic technique by determining precise coordinates on the Earth, by monitoring the variable Earth rotation and orientation with highest precision, and by deriving many other parameters of the Earth system. VLBI provides an important linkage to astronomy through, for instance, the determination of very precise coordinates of extragalactic radio sources. Additionally, it contributes to determining parameters of relativistic and cosmological models. After a short review of the history of geodetic VLBI and a summary of recent results, this paper describes future perspectives of this fascinating technique. The International VLBI Service for Geodesy and Astrometry (IVS), as a service of the International Association of Geodesy (IAG) and the International Astronomical Union (IAU), is well on its way to fully defining a next generation VLBI system, called VLBI2010. The goals of the new system are to achieve on scales up to the size of the Earth an accuracy of 1 mm in position and of 0.1 mm/year in velocity. Continuous observations shall be carried out 24 h per day 7 days per week in the future with initial results to be delivered within 24 h after taking the data. Special sessions, e.g. for monitoring the Earth rotation parameters, will provide the results in near real-time. These goals require a completely new technical and conceptual design of VLBI measurements. Based on extensive simulation studies, strategies have been developed by the IVS to significantly improve its product accuracy through the use of a network of small (approx 12 m) fast-slewing antennas. A new method for generating high precision delay measurements as well as improved methods for handling biases related to radio source structure, system electronics, and deformations of the antenna structures has been developed. Furthermore, as of January 2012, the construction of ten new VLBI2010 sites has been funded, with good prospects for one dozen more antennas, which will improve the geographical distribution of geodetic VLBI sites on Earth and provide an important step toward a global VLBI2010 network. Within this paper, the Global Geodetic Observing System (GGOS) of the IAG will also be introduced and the contribution of VLBI to GGOS will be described.
Hydrothermal systems on Mars: an assessment of present evidence
NASA Technical Reports Server (NTRS)
Farmer, J. D.
1996-01-01
Hydrothermal processes have been suggested to explain a number of observations for Mars, including D/H ratios of water extracted from Martian meteorites, as a means for removing CO2 from the Martian atmosphere and sequestering it in the crust as carbonates, and as a possible origin for iron oxide-rich spectral units on the floors of some rifted basins (chasmata). There are numerous examples of Martian channels formed by discharges of subsurface water near potential magmatic heat sources, and hydrothermal processes have also been proposed as a mechanism for aquifer recharge needed to sustain long term erosion of sapping channels. The following geological settings have been identified as targets for ancient hydrothermal systems on Mars: channels located along the margins of impact crater melt sheets and on the slopes of ancient volcanoes; chaotic and fretted terranes where shallow subsurface heat sources are thought to have interacted with ground ice; and the floors of calderas and rifted basins (e.g. chasmata). On Earth, such geological environments are often a locus for hydrothermal mineralization. But we presently lack the mineralogical information needed for a definitive evaluation of hypotheses. A preferred tool for identifying minerals by remote sensing methods on Earth is high spatial resolution, hyperspectral, near-infrared spectroscopy, a technique that has been extensively developed by mineral explorationists. Future efforts to explore Mars for ancient hydrothermal systems would benefit from the application of methods developed by the mining industry to look for similar deposits on Earth. But Earth-based exploration models must be adapted to account for the large differences in the climatic and geological history of Mars. For example, it is likely that the early surface environment of Mars was cool, perhaps consistently below freezing, with the shallow portions of hydrothermal systems being dominated by magma-cryosphere interactions. Given the smaller gravitational field, declining atmospheric pressure, and widespread, permeable megaregolith on Mars, volatile outgassing and magmatic cooling would have been more effective than on Earth. Thus, hydrothermal systems are likely to have had much lower average surface temperatures than comparable geological settings on Earth. The likely predominance of basaltic crust on Mars suggests that hydrothermal fluids and associated deposits should be enriched in Fe, Mg, Si and Ca, with surficial deposits being dominated by lower temperature, mixed iron oxide and carbonate mineralogies.
Hydrothermal systems on Mars: an assessment of present evidence.
Farmer, J D
1996-01-01
Hydrothermal processes have been suggested to explain a number of observations for Mars, including D/H ratios of water extracted from Martian meteorites, as a means for removing CO2 from the Martian atmosphere and sequestering it in the crust as carbonates, and as a possible origin for iron oxide-rich spectral units on the floors of some rifted basins (chasmata). There are numerous examples of Martian channels formed by discharges of subsurface water near potential magmatic heat sources, and hydrothermal processes have also been proposed as a mechanism for aquifer recharge needed to sustain long term erosion of sapping channels. The following geological settings have been identified as targets for ancient hydrothermal systems on Mars: channels located along the margins of impact crater melt sheets and on the slopes of ancient volcanoes; chaotic and fretted terranes where shallow subsurface heat sources are thought to have interacted with ground ice; and the floors of calderas and rifted basins (e.g. chasmata). On Earth, such geological environments are often a locus for hydrothermal mineralization. But we presently lack the mineralogical information needed for a definitive evaluation of hypotheses. A preferred tool for identifying minerals by remote sensing methods on Earth is high spatial resolution, hyperspectral, near-infrared spectroscopy, a technique that has been extensively developed by mineral explorationists. Future efforts to explore Mars for ancient hydrothermal systems would benefit from the application of methods developed by the mining industry to look for similar deposits on Earth. But Earth-based exploration models must be adapted to account for the large differences in the climatic and geological history of Mars. For example, it is likely that the early surface environment of Mars was cool, perhaps consistently below freezing, with the shallow portions of hydrothermal systems being dominated by magma-cryosphere interactions. Given the smaller gravitational field, declining atmospheric pressure, and widespread, permeable megaregolith on Mars, volatile outgassing and magmatic cooling would have been more effective than on Earth. Thus, hydrothermal systems are likely to have had much lower average surface temperatures than comparable geological settings on Earth. The likely predominance of basaltic crust on Mars suggests that hydrothermal fluids and associated deposits should be enriched in Fe, Mg, Si and Ca, with surficial deposits being dominated by lower temperature, mixed iron oxide and carbonate mineralogies.
Madhusoodhanan, C G; Sreeja, K G; Eldho, T I
2016-10-01
Climate change is a major concern in the twenty-first century and its assessments are associated with multiple uncertainties, exacerbated and confounded in the regions where human interventions are prevalent. The present study explores the challenges for climate change impact assessment on the water resources of India, one of the world's largest human-modified systems. The extensive human interventions in the Energy-Land-Water-Climate (ELWC) nexus significantly impact the water resources of the country. The direct human interventions in the landscape may surpass/amplify/mask the impacts of climate change and in the process also affect climate change itself. Uncertainties in climate and resource assessments add to the challenge. Formulating coherent resource and climate change policies in India would therefore require an integrated approach that would assess the multiple interlinkages in the ELWC nexus and distinguish the impacts of global climate change from that of regional human interventions. Concerted research efforts are also needed to incorporate the prominent linkages in the ELWC nexus in climate/earth system modelling.
NASA Technical Reports Server (NTRS)
Bonavito, N. L.; Gordon, C. L.; Inguva, R.; Serafino, G. N.; Barnes, R. A.
1994-01-01
NASA's Mission to Planet Earth (MTPE) will address important interdisciplinary and environmental issues such as global warming, ozone depletion, deforestation, acid rain, and the like with its long term satellite observations of the Earth and with its comprehensive Data and Information System. Extensive sets of satellite observations supporting MTPE will be provided by the Earth Observing System (EOS), while more specific process related observations will be provided by smaller Earth Probes. MTPE will use data from ground and airborne scientific investigations to supplement and validate the global observations obtained from satellite imagery, while the EOS satellites will support interdisciplinary research and model development. This is important for understanding the processes that control the global environment and for improving the prediction of events. In this paper we illustrate the potential for powerful artificial intelligence (AI) techniques when used in the analysis of the formidable problems that exist in the NASA Earth Science programs and of those to be encountered in the future MTPE and EOS programs. These techniques, based on the logical and probabilistic reasoning aspects of plausible inference, strongly emphasize the synergetic relation between data and information. As such, they are ideally suited for the analysis of the massive data streams to be provided by both MTPE and EOS. To demonstrate this, we address both the satellite imagery and model enhancement issues for the problem of ozone profile retrieval through a method based on plausible scientific inferencing. Since in the retrieval problem, the atmospheric ozone profile that is consistent with a given set of measured radiances may not be unique, an optimum statistical method is used to estimate a 'best' profile solution from the radiances and from additional a priori information.
NASA Astrophysics Data System (ADS)
Shankar, Mohan; Priestley, Kory; Smith, Nathaniel; Smith, Nitchie; Thomas, Susan; Walikainen, Dale
2015-10-01
The Clouds and Earth's Radiant Energy System (CERES) instruments help to study the impact of clouds on the earth's radiation budget. There are currently five instruments- two each on board Aqua and Terra spacecraft and one on the Suomi NPP spacecraft to measure the earth's reflected shortwave and emitted longwave energy, which represent two components of the earth's radiation energy budget. Flight Models (FM) 1 and 2 are on Terra, FM 3 and 4 are on Aqua, and FM5 is on Suomi NPP. The measurements are made by three sensors on each instrument: a shortwave sensor that measures the 0.3-5 microns wavelength band, a window sensor that measures the water vapor window between 8-12 microns, and a total sensor that measures all incident energy (0.3- >100 microns). The required accuracy of CERES measurements of 0.5% in the longwave and 1% in the shortwave is achieved through an extensive pre-launch ground calibration campaign as well as on-orbit calibration and validation activities. Onorbit calibration is carried out using the Internal Calibration Module (ICM) that consists of a tungsten lamp, blackbodies, and a solar diffuser known as the Mirror Attenuator Mosaic (MAM). The ICM calibration provides information about the stability of the sensors' broadband radiometric gains on-orbit. Several validation studies are conducted in order to monitor the behavior of the instruments in various spectral bands. The CERES Edition-4 data products for the FM1-FM4 instruments incorporate the latest calibration methodologies to improve on the Edition-3 data products. In this paper, we discuss the updated calibration methodology and present some validation studies to demonstrate the improvement in the trends using the CERES Edition-4 data products for all four instruments.
Physical characterization of the near-Earth object population
NASA Astrophysics Data System (ADS)
Ieva, S.; Dotto, E.; Mazzotta Epifani, E.; Perna, D.; Perozzi, E.; Micheli, M.
2017-08-01
The Near-Earth Object (NEO) population, being the remnants of the building blocks that originally formed our solar system, allows us to understand the initial conditions that were present in the protosolar nebula. Its investigation can provide crucial information on the origin and early evolution of the solar system, and shed light on the delivery of water and organic-rich material to the early Earth. Furthermore, the possible impact of NEOs poses a serious hazard to our planet. There is an urgent need to undertake a comprehensive physical characterization of the NEO population, particularly for the ones with the higher likelihood of catastrophic impact with the Earth. One of the main aims of the NEOShield-2 project (2015-2017), financed by the European Commission in the framework of the HORIZON 2020 program, is to undertake an extensive observational campaign and provide a physical and compositional characterization for a large number of NEOs in the < 300 m size range, retrieving in particular their mitigation-relevant properties (size, shape, albedo, diameter, composition, internal structure, ...) in order to design impact mitigation missions and assess the consequences of an impact on Earth. We carried out visible photometric measurements for a sample of 158 uncharacterized NEOs. We also made use of visible and near-infrared spectroscopy to assess NEO composition and perform a mineralogical analysis. We found that carbonaceous C-complex asteroids deserve a special attention, since their physical structure ( e.g., primitive nature, porosity) and their orbital parameters (mainly the inclination) make at the moment challenging the design of a successful mitigation strategy. Indeed, the most advanced mitigation technique (the kinetic impactor) is less effective on these bodies, and the high inclination of some possible impactors require a launch vehicle capability beyond the one currently available.
Microbial astronauts: assembling microbial communities for advanced life support systems.
Roberts, M S; Garland, J L; Mills, A L
2004-02-01
Extension of human habitation into space requires that humans carry with them many of the microorganisms with which they coexist on Earth. The ubiquity of microorganisms in close association with all living things and biogeochemical processes on Earth predicates that they must also play a critical role in maintaining the viability of human life in space. Even though bacterial populations exist as locally adapted ecotypes, the abundance of individuals in microbial species is so large that dispersal is unlikely to be limited by geographical barriers on Earth (i.e., for most environments "everything is everywhere" given enough time). This will not be true for microbial communities in space where local species richness will be relatively low because of sterilization protocols prior to launch and physical barriers between Earth and spacecraft after launch. Although community diversity will be sufficient to sustain ecosystem function at the onset, richness and evenness may decline over time such that biological systems either lose functional potential (e.g., bioreactors may fail to reduce BOD or nitrogen load) or become susceptible to invasion by human-associated microorganisms (pathogens) over time. Research at the John F. Kennedy Space Center has evaluated fundamental properties of microbial diversity and community assembly in prototype bioregenerative systems for NASA Advanced Life Support. Successional trends related to increased niche specialization, including an apparent increase in the proportion of nonculturable types of organisms, have been consistently observed. In addition, the stability of the microbial communities, as defined by their resistance to invasion by human-associated microorganisms, has been correlated to their diversity. Overall, these results reflect the significant challenges ahead for the assembly of stable, functional communities using gnotobiotic approaches, and the need to better define the basic biological principles that define ecosystem processes in the space environment. Copyright 2004 Springer-Verlag
Microbial astronauts: assembling microbial communities for advanced life support systems
NASA Technical Reports Server (NTRS)
Roberts, M. S.; Garland, J. L.; Mills, A. L.
2004-01-01
Extension of human habitation into space requires that humans carry with them many of the microorganisms with which they coexist on Earth. The ubiquity of microorganisms in close association with all living things and biogeochemical processes on Earth predicates that they must also play a critical role in maintaining the viability of human life in space. Even though bacterial populations exist as locally adapted ecotypes, the abundance of individuals in microbial species is so large that dispersal is unlikely to be limited by geographical barriers on Earth (i.e., for most environments "everything is everywhere" given enough time). This will not be true for microbial communities in space where local species richness will be relatively low because of sterilization protocols prior to launch and physical barriers between Earth and spacecraft after launch. Although community diversity will be sufficient to sustain ecosystem function at the onset, richness and evenness may decline over time such that biological systems either lose functional potential (e.g., bioreactors may fail to reduce BOD or nitrogen load) or become susceptible to invasion by human-associated microorganisms (pathogens) over time. Research at the John F. Kennedy Space Center has evaluated fundamental properties of microbial diversity and community assembly in prototype bioregenerative systems for NASA Advanced Life Support. Successional trends related to increased niche specialization, including an apparent increase in the proportion of nonculturable types of organisms, have been consistently observed. In addition, the stability of the microbial communities, as defined by their resistance to invasion by human-associated microorganisms, has been correlated to their diversity. Overall, these results reflect the significant challenges ahead for the assembly of stable, functional communities using gnotobiotic approaches, and the need to better define the basic biological principles that define ecosystem processes in the space environment. Copyright 2004 Springer-Verlag.
Fracture and earthquake physics in a non extensive view
NASA Astrophysics Data System (ADS)
Vallianatos, F.
2009-04-01
It is well known that the Gutenberg-Richter (G-R) power law distribution has to be modified for large seismic moments because of energy conservation and geometrical reasons. Several models have been proposed, either in terms of a second power law with a larger b value beyond a crossover magnitude, or based on a magnidute cut-off using an exponential taper. In the present work we point out that the non extensivity viewpoint is applicable to seismic processes. In the frame of a non-extensive approach which is based on Tsallis entropy we construct a generalized expression of Gutenberg-Richter (GGR) law. The existence of lower or/and upper bound to magnitude is discussed and the conditions under which GGR lead to classical GR law are analysed. For the lowest earthquake size (i.e., energy level) the correlation between the different parts of elements involved in the evolution of an earthquake are short-ranged and GR can be deduced on the basis of the maximum entropy principle using BG statistics. As the size (i.e., energy) increases, long range correlation becomes much more important, implying the necessity of using Tsallis entropy as an appropriate generalization of BG entropy. The power law behaviour is derived as a special case, leading to b-values being functions of the non-extensivity parameter q. Furthermore a theoretical analysis of similarities presented in stress stimulated electric and acoustic emissions and earthquakes are discussed not only in the frame of GGR but taking into account a universality in the description of intrevent times distribution. Its particular form can be well expressed in the frame of a non extensive approach. This formulation is very different from an exponential distribution expected for simple random Poisson processes and indicates the existence of a nontrivial universal mechanism in the generation process. All the aforementioned similarities within stress stimulated electrical and acoustic emissions and seismicity suggests a connection with fracture phenomena at much larger scales implying that a basic general mechanism is "actively hidden" behind all this phenomena. Acknowledgements: This work is partially supported by the Greek General Secretariat of Research and Technology in the frame of Crete Regional Project 2000- 2006 (M1.2): "TALOS: An integrated system of seismic hazard monitoring and management in the front of the Hellenic Arc", CRETE PEP 7 (KP 7). [1] F. Vallianatos and A. Tzanis, Phys. Chem. Earth 23, 933 (1998). [2] A. Tzanis and F. Vallianatos, Natural Hazards and Earth Syst, Sciences 3 (2003). [3] F. Vallianatos, D. Triantis, A. Tzanis, C. Anastasiadis and I. Stavrakas, Phys. Chem. Earth 29, 339 (2004). [4] C. Anastasiadis, D. Triantis, I. Stavrakas and F. Vallianatos, Ann. Geophys. 47, 21 (2004). [5] F. Vallianatos Proc., 2nd WSEAS Int. Conference on Seismology, (Cambridge, UK, 2008). [6] F. Vallianatos, Natural Hazards and Earth Syst, Sciences (2009).
2018-05-15
An extensive equatorial coronal hole has rotated so that it is now facing Earth (May 2-4, 2018). The dark coronal hole extends about halfway across the solar disk. It was observed in a wavelength of extreme ultraviolet light. This magnetically open area is streaming solar wind (i.e., a stream of charged particles released from the sun) into space. When Earth enters a solar wind stream and the stream interacts with our magnetosphere, we often experience nice displays of aurora. https://photojournal.jpl.nasa.gov/catalog/PIA00577
The earth and the moon /Harold Jeffreys Lecture/.
NASA Technical Reports Server (NTRS)
Press, F.
1971-01-01
The internal structures of the earth and the moon are compared in the light of the latest extensive data on the earth structure, mobility of the earth outer layers, and the properties of lunar crust. The Monte Carlo method is applied to develop an earth model by a stepwise process beginning with a random distribution of two elastic velocities and the density as a function of de pth. Lunar seismic, magnetic, and rock analysis data are used to infer the properties of the moon. The marked planetological contrast between the earth and the moon is shown to consist in that the earth is highly differentiated and still undergoes a large-scale differentiation, while the moon has lost its volatiles in its early history and has a cold dynamically inactive shell which has been without basic changes for three billion years.
List, Nanna Holmgaard; Kauczor, Joanna; Saue, Trond; Jensen, Hans Jørgen Aagaard; Norman, Patrick
2015-06-28
We present a formulation of molecular response theory for the description of a quantum mechanical molecular system in the presence of a weak, monochromatic, linearly polarized electromagnetic field without introducing truncated multipolar expansions. The presentation focuses on a description of linear absorption by adopting the energy-loss approach in combination with the complex polarization propagator formulation of response theory. Going beyond the electric-dipole approximation is essential whenever studying electric-dipole-forbidden transitions, and in general, non-dipolar effects become increasingly important when addressing spectroscopies involving higher-energy photons. These two aspects are examined by our study of the near K-edge X-ray absorption fine structure of the alkaline earth metals (Mg, Ca, Sr, Ba, and Ra) as well as the trans-polyenes. In following the series of alkaline earth metals, the sizes of non-dipolar effects are probed with respect to increasing photon energies and a detailed assessment of results is made in terms of studying the pertinent transition electron densities and in particular their spatial extension in comparison with the photon wavelength. Along the series of trans-polyenes, the sizes of non-dipolar effects are probed for X-ray spectroscopies on organic molecules with respect to the spatial extension of the chromophore.
Applying Strategic Visualization(Registered Trademark) to Lunar and Planetary Mission Design
NASA Technical Reports Server (NTRS)
Frassanito, John R.; Cooke, D. R.
2002-01-01
NASA teams, such as the NASA Exploration Team (NEXT), utilize advanced computational visualization processes to develop mission designs and architectures for lunar and planetary missions. One such process, Strategic Visualization (trademark), is a tool used extensively to help mission designers visualize various design alternatives and present them to other participants of their team. The participants, which may include NASA, industry, and the academic community, are distributed within a virtual network. Consequently, computer animation and other digital techniques provide an efficient means to communicate top-level technical information among team members. Today,Strategic Visualization(trademark) is used extensively both in the mission design process within the technical community, and to communicate the value of space exploration to the general public. Movies and digital images have been generated and shown on nationally broadcast television and the Internet, as well as in magazines and digital media. In our presentation will show excerpts of a computer-generated animation depicting the reference Earth/Moon L1 Libration Point Gateway architecture. The Gateway serves as a staging corridor for human expeditions to the lunar poles and other surface locations. Also shown are crew transfer systems and current reference lunar excursion vehicles as well as the Human and robotic construction of an inflatable telescope array for deployment to the Sun/Earth Libration Point.
Multi-scale, multi-model assessment of projected land allocation
NASA Astrophysics Data System (ADS)
Vernon, C. R.; Huang, M.; Chen, M.; Calvin, K. V.; Le Page, Y.; Kraucunas, I.
2017-12-01
Effects of land use and land cover change (LULCC) on climate are generally classified into two scale-dependent processes: biophysical and biogeochemical. An extensive amount of research has been conducted related to the impact of each process under alternative climate change futures. However, these studies are generally focused on the impacts of a single process and fail to bridge the gap between sector-driven scale dependencies and any associated dynamics. Studies have been conducted to better understand the relationship of these processes but their respective scale has not adequately captured overall interdependencies between land surface changes and changes in other human-earth systems (e.g., energy, water, economic, etc.). There has also been considerable uncertainty surrounding land use land cover downscaling approaches due to scale dependencies. Demeter, a land use land cover downscaling and change detection model, was created to address this science gap. Demeter is an open-source model written in Python that downscales zonal land allocation projections to the gridded resolution of a user-selected spatial base layer (e.g., MODIS, NLCD, EIA CCI, etc.). Demeter was designed to be fully extensible to allow for module inheritance and replacement for custom research needs, such as flexible IO design to facilitate the coupling of Earth system models (e.g., the Accelerated Climate Modeling for Energy (ACME) and the Community Earth System Model (CESM)) to integrated assessment models (e.g., the Global Change Assessment Model (GCAM)). In this study, we first assessed the sensitivity of downscaled LULCC scenarios at multiple resolutions from Demeter to its parameters by comparing them to historical LULC change data. "Optimal" values of key parameters for each region were identified and used to downscale GCAM-based future scenarios consistent with those in the Land Use Model Intercomparison Project (LUMIP). Demeter-downscaled land use scenarios were then compared to the default LUMIP scenarios to illustrate the uncertainties in projected LULC as a result of difference in downscaling algorithms. Our results show that such uncertainties could propagate to other components in ACME and CESM and lead to significant differences in simulated water and biogeochemical cycles.
NASA Astrophysics Data System (ADS)
Appel, Marius; Lahn, Florian; Pebesma, Edzer; Buytaert, Wouter; Moulds, Simon
2016-04-01
Today's amount of freely available data requires scientists to spend large parts of their work on data management. This is especially true in environmental sciences when working with large remote sensing datasets, such as obtained from earth-observation satellites like the Sentinel fleet. Many frameworks like SpatialHadoop or Apache Spark address the scalability but target programmers rather than data analysts, and are not dedicated to imagery or array data. In this work, we use the open-source data management and analytics system SciDB to bring large earth-observation datasets closer to analysts. Its underlying data representation as multidimensional arrays fits naturally to earth-observation datasets, distributes storage and computational load over multiple instances by multidimensional chunking, and also enables efficient time-series based analyses, which is usually difficult using file- or tile-based approaches. Existing interfaces to R and Python furthermore allow for scalable analytics with relatively little learning effort. However, interfacing SciDB and file-based earth-observation datasets that come as tiled temporal snapshots requires a lot of manual bookkeeping during ingestion, and SciDB natively only supports loading data from CSV-like and custom binary formatted files, which currently limits its practical use in earth-observation analytics. To make it easier to work with large multi-temporal datasets in SciDB, we developed software tools that enrich SciDB with earth observation metadata and allow working with commonly used file formats: (i) the SciDB extension library scidb4geo simplifies working with spatiotemporal arrays by adding relevant metadata to the database and (ii) the Geospatial Data Abstraction Library (GDAL) driver implementation scidb4gdal allows to ingest and export remote sensing imagery from and to a large number of file formats. Using added metadata on temporal resolution and coverage, the GDAL driver supports time-based ingestion of imagery to existing multi-temporal SciDB arrays. While our SciDB plugin works directly in the database, the GDAL driver has been specifically developed using a minimum amount of external dependencies (i.e. CURL). Source code for both tools is available from github [1]. We present these tools in a case-study that demonstrates the ingestion of multi-temporal tiled earth-observation data to SciDB, followed by a time-series analysis using R and SciDBR. Through the exclusive use of open-source software, our approach supports reproducibility in scalable large-scale earth-observation analytics. In the future, these tools can be used in an automated way to let scientists only work on ready-to-use SciDB arrays to significantly reduce the data management workload for domain scientists. [1] https://github.com/mappl/scidb4geo} and \\url{https://github.com/mappl/scidb4gdal
Recent advances in analytical satellite theory
NASA Technical Reports Server (NTRS)
Gaposchkin, E. M.
1978-01-01
Recent work on analytical satellite perturbation theory has involved the completion of a revision to 4th order for zonal harmonics, the addition of a treatment for ocean tides, an extension of the treatment for the noninertial reference system, and the completion of a theory for direct solar-radiation pressure and earth-albedo pressure. Combined with a theory for tesseral-harmonics, lunisolar, and body-tide perturbations, these formulations provide a comprehensive orbit-computation program. Detailed comparisons with numerical integration and observations are presented to assess the accuracy of each theoretical development.
International Space Station (ISS)
2007-08-01
As the construction continued on the International Space Station (ISS), STS-118 Astronaut Dave Williams, representing the Canadian Space Agency, participated in the fourth and final session of Extra Vehicular Activity (EVA). During the 5 hour space walk, Williams and Expedition 15 engineer Clay Anderson (out of frame) installed the External Wireless Instrumentation System Antenna, attached a stand for the shuttle robotic arm extension boom, and retrieved the two Materials International Space Station Experiments (MISSE) for return to Earth. MISSE collects information on how different materials weather in the environment of space.
Advanced Image Processing of Aerial Imagery
NASA Technical Reports Server (NTRS)
Woodell, Glenn; Jobson, Daniel J.; Rahman, Zia-ur; Hines, Glenn
2006-01-01
Aerial imagery of the Earth is an invaluable tool for the assessment of ground features, especially during times of disaster. Researchers at the NASA Langley Research Center have developed techniques which have proven to be useful for such imagery. Aerial imagery from various sources, including Langley's Boeing 757 Aries aircraft, has been studied extensively. This paper discusses these studies and demonstrates that better-than-observer imagery can be obtained even when visibility is severely compromised. A real-time, multi-spectral experimental system will be described and numerous examples will be shown.
More sense for less cents: Cost effective servicing of remote sensing satellites
NASA Technical Reports Server (NTRS)
Lee, Jeannie; Misencik, Tom; Robertson, Bill; Sliney, Jack
1993-01-01
This paper addresses the design considerations for Earth observation spacecraft bus and payload subsystems such that cost-effective spacecraft maintainability is enhanced through optimized reliability and the application of robotic on-orbit support. In the past, for most satellites, maintainability has been associated with the clever application of telemetry reconfiguration and the use of redundant systems as necessary over the life cycle of the spacecraft. This presentation addresses the opportunities and challenges of leveraging the extensive work already accomplished in the development of on-orbit servicing technologies.
NASA Technical Reports Server (NTRS)
Sagan, C.; Thompson, W. R.; Khare, B. N.
1985-01-01
Voyager discovered nine simple organic molecules in the atmosphere of Titan. Complex organic solids, called tholins, produced by irradiation of the simulated Titanian atmosphere, are consistent with measured properties of Titan from ultraviolet to microwave frequencies and are the likely main constituents of the observed red aerosols. The tholins contain many of the organic building blocks central to life on earth. At least 100-m, and possibly kms thicknesses of complex organics have been produced on Titan during the age of the solar system, and may exist today as submarine deposits beneath an extensive ocean of simple hydrocarbons.
NASA Technical Reports Server (NTRS)
Wilcox, Brian H.; Schneider, Evan G.; Vaughan, David A.; Hall, Jeffrey L.; Yu, Chi Yau
2011-01-01
As we have previously reported, it may be possible to launch payloads into low-Earth orbit (LEO) at a per-kilogram cost that is one to two orders of magnitude lower than current launch systems, using only a relatively small capital investment (comparable to a single large present-day launch). An attractive payload would be large quantities of high-performance chemical rocket propellant (e.g. Liquid Oxygen/Liquid Hydrogen (LO2/LH2)) that would greatly facilitate, if not enable, extensive exploration of the moon, Mars, and beyond.
STS-118 Astronaut Williams and Expedition 15 Engineer Anderson Perform EVA
NASA Technical Reports Server (NTRS)
2007-01-01
As the construction continued on the International Space Station (ISS), STS-118 Astronaut Dave Williams, representing the Canadian Space Agency, participated in the fourth and final session of Extra Vehicular Activity (EVA). During the 5 hour space walk, Williams and Expedition 15 engineer Clay Anderson (out of frame) installed the External Wireless Instrumentation System Antenna, attached a stand for the shuttle robotic arm extension boom, and retrieved the two Materials International Space Station Experiments (MISSE) for return to Earth. MISSE collects information on how different materials weather in the environment of space.
Evidence for subduction in the ice shell of Europa
NASA Astrophysics Data System (ADS)
Kattenhorn, Simon A.; Prockter, Louise M.
2014-10-01
Jupiter’s icy moon Europa has one of the youngest planetary surfaces in the Solar System, implying rapid recycling by some mechanism. Despite ubiquitous extension and creation of new surface area at dilational bands that resemble terrestrial mid-ocean spreading zones, there is little evidence of large-scale contraction to balance the observed extension or to recycle ageing terrains. We address this enigma by presenting several lines of evidence that subduction may be recycling surface material into the interior of Europa’s ice shell. Using Galileo spacecraft images, we produce a tectonic reconstruction of geologic features across a 134,000 km2 region of Europa and find, in addition to dilational band spreading, evidence for transform motions along prominent strike-slip faults, as well as the removal of approximately 20,000 km2 of the surface along a discrete tabular zone. We interpret this zone as a subduction-like convergent boundary that abruptly truncates older geological features and is flanked by potential cryolavas on the overriding ice. We propose that Europa’s ice shell has a brittle, mobile, plate-like system above convecting warmer ice. Hence, Europa may be the only Solar System body other than Earth to exhibit a system of plate tectonics.
Expanding the role of reactive transport models in critical zone processes
Li, Li; Maher, Kate; Navarre-Sitchler, Alexis; Druhan, Jennifer; Meile, Christof; Lawrence, Corey; Moore, Joel; Perdrial, Julia; Sullivan, Pamela; Thompson, Aaron; Jin, Lixin; Bolton, Edward W.; Brantley, Susan L.; Dietrich, William E.; Mayer, K. Ulrich; Steefel, Carl; Valocchi, Albert J.; Zachara, John M.; Kocar, Benjamin D.; McIntosh, Jennifer; Tutolo, Benjamin M.; Kumar, Mukesh; Sonnenthal, Eric; Bao, Chen; Beisman, Joe
2017-01-01
Models test our understanding of processes and can reach beyond the spatial and temporal scales of measurements. Multi-component Reactive Transport Models (RTMs), initially developed more than three decades ago, have been used extensively to explore the interactions of geothermal, hydrologic, geochemical, and geobiological processes in subsurface systems. Driven by extensive data sets now available from intensive measurement efforts, there is a pressing need to couple RTMs with other community models to explore non-linear interactions among the atmosphere, hydrosphere, biosphere, and geosphere. Here we briefly review the history of RTM development, summarize the current state of RTM approaches, and identify new research directions, opportunities, and infrastructure needs to broaden the use of RTMs. In particular, we envision the expanded use of RTMs in advancing process understanding in the Critical Zone, the veneer of the Earth that extends from the top of vegetation to the bottom of groundwater. We argue that, although parsimonious models are essential at larger scales, process-based models offer tools to explore the highly nonlinear coupling that characterizes natural systems. We present seven testable hypotheses that emphasize the unique capabilities of process-based RTMs for (1) elucidating chemical weathering and its physical and biogeochemical drivers; (2) understanding the interactions among roots, micro-organisms, carbon, water, and minerals in the rhizosphere; (3) assessing the effects of heterogeneity across spatial and temporal scales; and (4) integrating the vast quantity of novel data, including “omics” data (genomics, transcriptomics, proteomics, metabolomics), elemental concentration and speciation data, and isotope data into our understanding of complex earth surface systems. With strong support from data-driven sciences, we are now in an exciting era where integration of RTM framework into other community models will facilitate process understanding across disciplines and across scales.
Supercontinental Cycles and the Tectonic Modulation of Earth's Climate
NASA Astrophysics Data System (ADS)
Jellinek, M.; Pierrehumbert, R.; Turchyn, A. V.; Lenardic, A.
2012-12-01
Plate tectonics involves the production of oceanic plates at spreading ridges, their destruction at subduction zones, where they sink into the underlying mantle as cold plumes, and a slow drift of buoyant continents at the surface. The resulting laterally and vertically extensive internal mantle motions cool the Earth efficiently and with remarkable consequences including long-lived hotspot volcanoes such as Hawaii, a persistent and strong magnetic field and a habitable climate. Over the last billion years, however, this regular mantle overturning and thorough thermal mixing has been punctuated by 2 transient periods during which the continents were drawn together to form the supercontinents Rodinia and Pangea. These supercontinents were encircled to differing extents by subduction zones where partial or complete "curtains" of cold downgoing oceanic slabs inhibited lateral mantle stirring, leading, in turn, to large temperature variations between the more rapidly cooled oceanic mantle and the more slowly cooled continental mantle. A key prediction from theory, numerical simulations and laboratory experiments is that, depending on the mantle thermal mixing efficiency, the relative cooling of the oceanic mantle during the formation of supercontinents will cause crustal production at spreading ridges to decline or cease entirely. We investigate two further provocative implications for Earth's climate during the Pangea and Rodinia supercontinental epochs. First, the total volcanic influx of CO2 to the ocean-atmosphere system may decline by 30-40%, probably causing a modest global cooling. Second, a near absence of basaltic crust at ridges exposes mantle rocks to seawater, which leads to extensive serpentinization and to a potentially large flux of abiogenic methane (CH4) into the deep ocean. Whereas we expect all of this CH4 to be oxidized in the oxygen-rich and biologically complex Pangean ocean, some fraction of this CH4 flux may contribute to the composition of low-oxygen Rodinian atmosphere and influence climate in remarkable ways. A particular situation we explore is whether the transient mantle dynamics of the formation and breakup of Rodinia ultimately caused Earth to enter into, and exit from, periods of global glaciation consistent with the snowball Earth hypothesis.
RIES - Rijnland Internet Election System: A Cursory Study of Published Source Code
NASA Astrophysics Data System (ADS)
Gonggrijp, Rop; Hengeveld, Willem-Jan; Hotting, Eelco; Schmidt, Sebastian; Weidemann, Frederik
The Rijnland Internet Election System (RIES) is a system designed for voting in public elections over the internet. A rather cursory scan of the source code to RIES showed a significant lack of security-awareness among the programmers which - among other things - appears to have left RIES vulnerable to near-trivial attacks. If it had not been for independent studies finding problems, RIES would have been used in the 2008 Water Board elections, possibly handling a million votes or more. While RIES was more extensively studied to find cryptographic shortcomings, our work shows that more down-to-earth secure design practices can be at least as important, and the aspects need to be examined much sooner than right before an election.
NASA Technical Reports Server (NTRS)
Mord, Allan J.; Snyder, Howard A.; Kilpatrick, Kathleen A.; Hermanson, Lynn A.; Hopkins, Richard A.; Vangundy, Donald A.
1988-01-01
A system for measuring the mass of liquid in a tank on orbit with 1 percent accuracy was developed and demonstrated. An extensive tradeoff identified adiabatic compression as the only gaging technique that is independent of gravity or its orientation, and of the size and distribution of bubbles in the tank. This technique is applicable to all Earth-storable and cryogenic liquids of interest for Space Station use, except superfluid helium, and can be applied to tanks of any size, shape, or internal structure. Accuracy of 0.2 percent was demonstrated in the laboratory, and a detailed analytical model was developed and verified by testing. A flight system architecture is presented that allows meeting the needs of a broad range of space fluid systems without custom development for each user.
BOREAS Level-1B TIMS Imagery: At-sensor Radiance in BSQ Format
NASA Technical Reports Server (NTRS)
Hall, Forrest G. (Editor); Nickeson, Jaime (Editor); Strub, Richard; Newcomer, Jeffrey A.; Chernobieff, Sonia
2000-01-01
The Boreal Ecosystem-Atmospheric Study (BOREAS) Staff Science Aircraft Data Acquisition Program focused on providing the research teams with the remotely sensed satellite data products they needed to compare and spatially extend point results. For BOREAS, the Thermal Infrared Multispectral Scanner (TIMS) imagery, along with other aircraft images, was collected to provide spatially extensive information over the primary study areas. The Level-1b TIMS images cover the time periods of 16 to 20 Apr 1994 and 06 to 17 Sep 1994. The system calibrated images are stored in binary image format files. The TIMS images are available from the Earth Observing System Data and Information System (EOSDIS) Oak Ridge National Laboratory (ORNL) Distributed Active Archive Center (DAAC).
An advanced domestic satellite communications system
NASA Technical Reports Server (NTRS)
1980-01-01
An updated traffic projection for U.S. domestic satellite communications service covering a period of 15 years; mid-1980 to mid-1995 was prepared. This model takes into account expected technology advances and reductions in transmission costs, legislative and regulatory changes permitting increased competition, and rising energy costs which will encourage more extensive substitution of telecommunications for travel. The historical development and current status of satellite systems are discussed as well as the characteristics of follow-on systems. Orbital arc utilization, spacecraft configuration for single shuttle launch, Earth station configuration, and system costs are examined. Areas which require technology development include multiple beam frequency reuse antennas, on-board switching, intersatellite links, and ka-band operation. Packing and deployment schemes for enclosing the satellite within the shuttle orbiter bay must also be devised.
Processing the Viking lander camera data
NASA Technical Reports Server (NTRS)
Levinthal, E. C.; Tucker, R.; Green, W.; Jones, K. L.
1977-01-01
Over 1000 camera events were returned from the two Viking landers during the Primary Mission. A system was devised for processing camera data as they were received, in real time, from the Deep Space Network. This system provided a flexible choice of parameters for three computer-enhanced versions of the data for display or hard-copy generation. Software systems allowed all but 0.3% of the imagery scan lines received on earth to be placed correctly in the camera data record. A second-order processing system was developed which allowed extensive interactive image processing including computer-assisted photogrammetry, a variety of geometric and photometric transformations, mosaicking, and color balancing using six different filtered images of a common scene. These results have been completely cataloged and documented to produce an Experiment Data Record.
Subsetting and Formatting Landsat-7 LOR ETM+ and Data Products
NASA Technical Reports Server (NTRS)
Reid, Michael R.
2000-01-01
The Landsat-7 Processing System (LPS) processes Landsat-7 Enhanced Thematic Mapper (ETM+) instrument data into large, contiguous segments called "subintervals" and stores them in Level OR (LOR) data files. The LPS processed subinterval products must be subsetted and reformatted before the Level I processing systems can ingest them. The initial full subintervals produced by the LPS are stored mainly in HDF Earth Observing System (HDF-EOS) format which is an extension to the Hierarchical Data Format (HDF). The final LOR products are stored in native HDF format. Primarily the EOS Core System (ECS) and alternately the DAAC Emergency System (DES) subset the subinterval data for the operational Landsat-7 data processing systems. The HDF and HDF-EOS application programming interfaces (APIs) can be used for extensive data subsetting and data reorganization. A stand-alone subsetter tool has been developed which is based on some of the DES code. This tool makes use of the HDF and HDFEOS APIs to perform Landsat-7 LOR product subsetting and demonstrates how HDF and HDFEOS can be used for creating various configurations of full LOR products. How these APIs can be used to efficiently subset, format, and organize Landsat-7 LOR data as demonstrated by the subsetter tool and the DES is discussed.
NASA Technical Reports Server (NTRS)
Sercel, Joel C.
1990-01-01
The use of solar system resources for human industry can be viewed as a natural extension of the continual growth of our species' habitat. Motivations for human activities in space can be discussed in terms of five distinct areas: (1) information processing and collection; (2) materials processing; (3) energy production to meet terrestrial power needs; (4) the use of extraterrestrial materials; and (5) disaster avoidance. When considering 21st-Century activities in space, each of these basic motivations must be treated in light of issues likely to be relevant to the 21st-Century earth. Many of the problems facing 21st-Century earth may stem from the need to maintain the world population of 8 to 10 billion people as is projected from expected growth rates. These problems are likely to include managing the impact of industrial processes on the terrestrial biosphere while providing adequate energy production and material goods for the growing population. The most important human activities in space in the latter half of the 21st Century may be associated with harnessing the resources of the near-earth asteroids for industrial processes. These above topics are discussed with an emphasis on space industrialization.
Gallium isotopic evidence for extensive volatile loss from the Moon during its formation
Kato, Chizu; Moynier, Frédéric
2017-01-01
The distribution and isotopic composition of volatile elements in planetary materials holds a key to the characterization of the early solar system and the Moon’s formation. The Moon and Earth are chemically and isotopically very similar. However, the Moon is highly depleted in volatile elements and the origin of this depletion is still debated. We present gallium isotopic and elemental measurements in a large set of lunar samples to constrain the origin of this volatile depletion. We show that while Ga has a geochemical behavior different from zinc, both elements show a systematic enrichment in the heavier isotopes in lunar mare basalts and Mg-suite rocks compared to the silicate Earth, pointing to a global-scale depletion event. On the other hand, the ferroan anorthosites are isotopically heterogeneous, suggesting a secondary distribution of Ga at the surface of the Moon by volatilization and condensation. The isotopic difference of Ga between Earth and the Moon and the isotopic heterogeneity of the crustal ferroan anorthosites suggest that the volatile depletion occurred following the giant impact and during the lunar magma ocean phase. These results point toward a Moon that has lost its volatile elements during a whole-scale evaporation event and that is now relatively dry compared to Earth. PMID:28782027
Extending VIVO, a semantic web app, to share semantic data across institutions
NASA Astrophysics Data System (ADS)
Rowan, Linda R.; Gross, M. Benjamin; Mayernik, Matthew; Khan, Huda; Boler, Frances; Maull, Keith; Stott, Don; Johns, Erica; Daniels, Michael; Krafft, Dean; Meertens, Charles
2017-04-01
The EarthCollab project, a U.S. National Science Foundation EarthCube Building Block, is extending an existing open-source semantic web application, VIVO, to enable the exchange of information about scientific researchers and resources across institutions. VIVO has been implemented by more than 100 universities and research institutions to highlight research and institutional achievements. Most implementations of VIVO, however, gather information about a single organization. The EarthCollab project VIVO extensions enable cross-linking of VIVO instances to reduce duplication of information about the same people and scientific resources, and enable dynamic linking of related information across VIVO installations. EarthCollab is a collaboration between UNAVCO, a geodetic facility and consortium that supports diverse research projects informed by geodesy, The Bering Sea Project, an interdisciplinary field program whose data archive is hosted by NCAR's Earth Observing Laboratory, and Cornell University. Test cross-linking implementations have been deployed by UNAVCO and Cornell to demonstrate the following core features: 1. Look up people and things at an external VIVO instance, 2. Assert equivalence between URIs at the two institutions (i.e., a person) using the 'owl:sameAs' property, 3. Provide a subset of data as RDF and JSON as a service from one institution, 4. Display the data requested from the service at the other institution's site, and 5. Allow a user to distinguish between data sources when displayed on one page. Currently, a curator makes the 'sameAs' assertions manually, but persistent and unique identifiers such as ORCIDs for people and DOIs for datasets could be used to automate the process. As development of the cross-linking extension continues, we must address a number of open questions. For example, if cross-linking institutions have duplicate or conflicting information, should one institution be considered the canonical source, or should the information be displayed in parallel? Should cross-linked data be cached locally in case of a service disruption on the external system? For what types of information can we leverage public persistent identifier lookup services to automate 'sameAs' assertions? Solutions to these challenges will be the focus of EarthCollab's continued development and eventual inclusion of cross-linking features in the core VIVO code.
NASA Astrophysics Data System (ADS)
Sanders, Gerald B.; Larson, William E.
2015-05-01
A key aspect of enabling an affordable and sustainable program of human exploration beyond low Earth orbit is the ability to locate, extract, and harness the resources found in space to reduce what needs to be launched from Earth's deep gravity well and to minimize the risk of dependence on Earth for survival. Known as In Situ Resource Utilization or ISRU, the ability to convert space resources into useful and mission critical products has been shown in numerous studies to be mission and architecture enhancing or enabling. However at the time of the release of the US Vision for Space Exploration in 2004, only concept feasibility hardware for ISRU technologies and capabilities had been built and tested in the laboratory; no ISRU hardware had ever flown in a mission to the Moon or Mars. As a result, an ISRU development project was established with phased development of multiple generations of hardware and systems. To bridge the gap between past ISRU feasibility hardware and future hardware needed for space missions, and to increase confidence in mission and architecture planners that ISRU capabilities would meet exploration needs, the ISRU development project incorporated extensive ground and analog site testing to mature hardware, operations, and interconnectivity with other exploration systems linked to ISRU products. This report documents the series of analog test activities performed from 2008 to 2012, the stepwise progress achieved, and the end-to-end system and mission demonstrations accomplished in this test program.
Gravity field, geoid and ocean surface by space techniques
NASA Technical Reports Server (NTRS)
Anderle, R. J.
1978-01-01
Knowledge of the earth's gravity field continued to increase during the last four years. Altimetry data from the GEOS-3 satellite has provided the geoid over most of the ocean to an accuracy of about one meter. Increasing amounts of laser data has permitted the solution for 566 terms in the gravity field with which orbits of the GEOS-3 satellite have been computed to an accuracy of about one to two meters. The combination of satellite tracking data, altimetry and gravimetry has yielded a solution for 1360 terms in the earth's gravity field. A number of problems remain to be solved to increase the accuracy of the gravity field determination. New satellite systems would provide gravity data in unsurveyed areas and correction for topographic features of the ocean and improved computational procedures together with a more extensive laser network will considerably improve the accuracy of the results.
Intra-annual NDVI validation of the Landsat 5 TM radiometric calibration
Chander, G.; Groeneveld, D.P.
2009-01-01
Multispectral data from the Landsat 5 (L5) Thematic Mapper (TM) sensor provide the backbone of the extensive archive of moderate‐resolution Earth imagery. Even after more than 24 years of service, the L5 TM is still operational. Given the longevity of the satellite, the detectors have aged and the sensor's radiometric characteristics have changed since launch. The calibration procedures and parameters in the National Land Archive Production System (NLAPS) have also changed with time. Revised radiometric calibrations in 2003 and 2007 have improved the radiometric accuracy of recently processed data. This letter uses the Normalized Difference Vegetation Index (NDVI) as a metric to evaluate the radiometric calibration. The calibration change has improved absolute calibration accuracy, consistency over time, and consistency with Landsat 7 (L7) Enhanced Thematic radiometry and will provide the basis for continued long‐term studies of the Earth's land surfaces.
Survey of visualization and analysis tools
NASA Technical Reports Server (NTRS)
Meyer, P. J.
1994-01-01
A large number of commercially available visualization and analysis tools are available to the researcher. Some of the strengths and limitations of some of these tools, from the viewpoint of the earth sciences discipline, are discussed. Visualization and analysis tools fall into one of two categories: those that are designed to a specific purpose and are non-extensive and those that are generic visual programming tools that are extensible. Most of the extensible packages examined incorporate a data flow paradigm.
(abstract) Effect of Long Period Ocean Tides on the Earth's Rotation
NASA Technical Reports Server (NTRS)
Gross, R. S.; Chao, B. F.; Desai, S.
1996-01-01
The second-degree zonal tide raising potential, which is responsible for tidal changes in the Earth's rotation rate and length-of-day, is symmetric about the polar axis and hence can excite the Earth's polar motion only through its action upon nonaxisymmetric features of the Earth such as the oceans. Ocean tidal excitation of polar motion in the diurnal and semidiurnal tidal bands has been previously detected and extensively examined. Here, the detection of ocean tidal excitation of polar motion in the long-period tidal band, specifically at the Mf' (13.63-day) and Mf (13.66-day) tidal frequencies, is reported.
Pioneer 7 observations of plasma flow and field reversal regions in the distant geomagnetic tail
NASA Technical Reports Server (NTRS)
Walker, R. C.; Lazarus, A. J.; Villante, U.
1975-01-01
The present paper gives the results of an extensive analysis of plasma and magnetic-field data from Pioneer 7 taken in the geomagnetic tail approximately 1000 earth radii downstream from earth. The principal observations are: (1) measurable fluxes of protons in the tail, flowing away from earth, sometimes with a double-peaked velocity distribution; (2) field reversal regions in which the field changes from radial to antiradial by a vector rotation in the north-south plane; and (3) general characteristics of the tail similar to those observed near earth with good correlation between taillike magnetic fields and plasma.
Near-Earth Objects. Chapter 27
NASA Technical Reports Server (NTRS)
Harris, Alan W.; Drube, Line; McFadden, Lucy A.; Binzel, Richard P.
2014-01-01
A near-Earth object (NEO) is an asteroid or comet orbiting the Sun with a perihelion distance of less than 1.3 Astronomical Units (AU) (1 AU, an astronomical unit, is the mean distance between the Earth and the Sun, around 150 million kilometers). If the orbit of an NEO can bring it to within 0.05 AU of the Earth's orbit, and it is larger than about 120 meters, it is termed a potentially hazardous object (PHO); an object of this size is likely to survive passage through the atmosphere and cause extensive damage on impact. (The acronyms NEA and PHO are used when referring specifically to asteroids.)
The Programming Language Python In Earth System Simulations
NASA Astrophysics Data System (ADS)
Gross, L.; Imranullah, A.; Mora, P.; Saez, E.; Smillie, J.; Wang, C.
2004-12-01
Mathematical models in earth sciences base on the solution of systems of coupled, non-linear, time-dependent partial differential equations (PDEs). The spatial and time-scale vary from a planetary scale and million years for convection problems to 100km and 10 years for fault systems simulations. Various techniques are in use to deal with the time dependency (e.g. Crank-Nicholson), with the non-linearity (e.g. Newton-Raphson) and weakly coupled equations (e.g. non-linear Gauss-Seidel). Besides these high-level solution algorithms discretization methods (e.g. finite element method (FEM), boundary element method (BEM)) are used to deal with spatial derivatives. Typically, large-scale, three dimensional meshes are required to resolve geometrical complexity (e.g. in the case of fault systems) or features in the solution (e.g. in mantel convection simulations). The modelling environment escript allows the rapid implementation of new physics as required for the development of simulation codes in earth sciences. Its main object is to provide a programming language, where the user can define new models and rapidly develop high-level solution algorithms. The current implementation is linked with the finite element package finley as a PDE solver. However, the design is open and other discretization technologies such as finite differences and boundary element methods could be included. escript is implemented as an extension of the interactive programming environment python (see www.python.org). Key concepts introduced are Data objects, which are holding values on nodes or elements of the finite element mesh, and linearPDE objects, which are defining linear partial differential equations to be solved by the underlying discretization technology. In this paper we will show the basic concepts of escript and will show how escript is used to implement a simulation code for interacting fault systems. We will show some results of large-scale, parallel simulations on an SGI Altix system. Acknowledgements: Project work is supported by Australian Commonwealth Government through the Australian Computational Earth Systems Simulator Major National Research Facility, Queensland State Government Smart State Research Facility Fund, The University of Queensland and SGI.
The Physical, Geological, and Dynamical Nature of Asteroid (101955) Bennu - Target of OSIRIS-REx
NASA Astrophysics Data System (ADS)
Lauretta, Dante
2014-11-01
OSIRIS-REx will survey asteroid (101955) Bennu to understand its properties, assess its resource potential, refine the impact hazard, and return a sample to Earth. This mission launches in 2016. Bennu is different from all other near-Earth asteroids previously visited by spacecraft. (433) Eros, target of the NEAR-Shoemaker mission, and (25143) Itokawa, target of Hayabusa, are both high-albedo, S-type asteroids with irregular shapes. In contrast, Bennu has a low albedo, is a B-type asteroid, and has a distinct spheroidal shape. While Eros and Itokawa are similar to ordinary chondrites, Bennu is likely related to carbonaceous chondrites, meteorites that record the history of volatiles and organic compounds in the early Solar System.We performed an extensive campaign to determine the properties of Bennu. This investigation provides information on the orbit, shape, mass, rotation state, radar response, photometric, spectroscopic, thermal, regolith, and environmental properties of Bennu. Combining these data with cosmochemical and dynamical models yields a hypothetical timeline for Bennu’s formation and evolution. Bennu is an ancient object that has witnessed over 4.5 Gyr of Solar System history. Its chemistry and mineralogy were established within the first 10 Myr of the Solar System. It likely originated as a discrete asteroid in the main belt ~0.7 - 2 Gyr ago as a fragment from the catastrophic disruption of a large, carbonaceous asteroid. It was delivered to near-Earth space via a combination of Yarkovsky-induced drift and interaction with giant-planet resonances. During its journey, YORP processes and planetary encounters modified Bennu’s spin state, potentially reshaping and resurfacing the asteroid. Bennu is a Potentially Hazardous Asteroids with an ~1-in-2700 chance of impacting the Earth in the late 22nd century. It will most likely end its dynamical life by falling into the Sun. The highest probability for a planetary impact is with Venus, followed by the Earth. There is a chance that Bennu will be ejected from the inner Solar System after a close encounter with Jupiter. OSIRIS-REx will return samples from this intriguing asteroid in September 2023.
Children's Concepts of the Shape and Size of the Earth, Sun and Moon
ERIC Educational Resources Information Center
Bryce, T. G. K.; Blown, E. J.
2013-01-01
Children's understandings of the shape and relative sizes of the Earth, Sun and Moon have been extensively researched and in a variety of ways. Much is known about the confusions which arise as young people try to grasp ideas about the world and our neighbouring celestial bodies. Despite this, there remain uncertainties about the conceptual models…
2017-12-08
NASA’s C130 Hercules is a four-engine turboprop. This particular plane was built in 1966, but has been extensively retrofitted for scientific use. --- The North Atlantic Aerosols and Marine Ecosystems Study (NAAMES) is a five year investigation to resolve key processes controlling ocean system function, their influences on atmospheric aerosols and clouds and their implications for climate. Michael Starobin joined the NAAMES field campaign on behalf of Earth Expeditions and NASA Goddard Space Flight Center’s Office of Communications. He presented stories about the important, multi-disciplinary research being conducted by the NAAMES team, with an eye towards future missions on the NASA drawing board. This is a NAAMES photo essay put together by Starobin, a collection of 49 photographs and captions. Photo and Caption Credit: Michael Starobin 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
TRAPPIST-1 Planet Lineup - Updated Feb. 2018
2018-02-05
This chart shows, on the top row, artist concepts of the seven planets of TRAPPIST-1 with their orbital periods, distances from their star, radii, masses, densities and surface gravity as compared to those of Earth. These numbers are current as of February 2018. On the bottom row, the same numbers are displayed for the bodies of our inner solar system: Mercury, Venus, Earth and Mars. The TRAPPIST-1 planets orbit their star extremely closely, with periods ranging from 1.5 to only about 20 days. This is much shorter than the period of Mercury, which orbits our sun in about 88 days. The masses and densities of the TRAPPIST-1 planets were determined by careful measurements of slight variations in the timings of their orbits using extensive observations made by NASA's Spitzer and Kepler space telescopes, in combination with data from Hubble and a number of ground-based telescopes. These measurements are the most precise to date for any system of exoplanets. In this illustration, the relative sizes of the planets are all shown to scale. https://photojournal.jpl.nasa.gov/catalog/PIA22094
NASA Astrophysics Data System (ADS)
Boudon, Vincent; Sears, Trevor; Coheur, Pierre-François
2018-06-01
Changes to the Earth's climate system resulting from modification of the atmosphere caused by both anthropogenic and natural effects are one of the great long-term threats to our society. In order to measure and understand the drivers of these changes, quantitative field measurements combined with precise and accurate laboratory data are needed. The Kyoto Protocol [1], signed in 1997, focused the scientific community on the need for data aimed at developing a better understanding of the physics and chemistry of molecular and aerosol species that lead to long-term climate change. The results have been impressive. Continuous and extensive concentration measurements are now being performed from the ground, e.g. the TCCON network, from balloons and airplanes and, of course, from space (e.g. ACE-Scisat, TANSO-GOSAT, IASI-Metop, OCO-2, Sentinel-5P, …). With the observing system now in place the concentration profiles of a suite of species, including greenhouse gases, aerosol precursors and others are measured with increasing precision over large areas of the Earth, leading to a much more complete understanding of the radiative forcing budget.
Another Look at the Markowitz Wobble
NASA Astrophysics Data System (ADS)
Dickman, S. R.
2006-05-01
The Markowitz wobble is a small-amplitude, irregular, long-period feature of Earth's polar motion. Despite a contentious history, doubts concerning its existence have apparently faded in recent decades (see, e.g., Poma 2000), and several studies have addressed the question of its excitation. Among the most promising is the proposal by Dumberry & Bloxham (2002; see also Dumberry 2005 and Guo & Buffett 2005) that gravitational and inertial coupling between the mantle and an inner core tilted periodically by outer core hydromagnetic oscillations could - under optimal conditions - reproduce key characteristics of the Markowitz wobble. Those conditions include a moderately high inner core viscosity and high magnetic field strength at the inner core boundary, and fluid core oscillations with a ~ 30-year period. In contrast, oceanic and atmospheric angular momentum variations marginally fail to excite decadal polar motion to the observed level (Gross et al. 2005, also Celaya et al. 1999; but see de Viron et al. 2004). In 1983 I showed that, if the oceans and solid earth were treated as a tightly coupled two-body rotating system, it was possible (depending on the mathematical form of the coupling) for the system to possess 2 natural wobble frequencies corresponding fairly well to the observed Chandler and Markowitz wobbles. The treatment depended on assuming that the oceans respond in an equilibrium manner to rotational perturbations, an approximation justified by the long periods of those wobbles. If the Markowitz wobble is indeed a natural resonance of the ocean - solid earth system, the effectiveness of all proposed excitation sources might require re-evaluation. For this talk I have revisited my earlier investigation, extending the theory to account for dynamic oceanic behavior in response to perturbations of the two-body system's rotation. The extension is based on the "broad-band" approach I employed (in 1993) for determining tidal effects on rotation. Results will be presented for various types of ocean - earth coupling.
Exposing the Strategies that can Reduce the Obstacles: Improving the Science User Experience
NASA Astrophysics Data System (ADS)
Lindsay, F. E.; Brennan, J.; Behnke, J.; Lynnes, C.
2017-12-01
It is now well established that pursuing generic solutions to what seem are common problems in Earth science data access and use can often lead to disappointing results for both system developers and the intended users. This presentation focuses on real-world experience of managing a large and complex data system, NASA's Earth Science Data and Information Science System (EOSDIS), whose mission is to serve both broad user communities and those in smaller niche applications of Earth science data and services. In the talk, we focus on our experiences with known data user obstacles characterizing EOSDIS approaches, including various technological techniques, for engaging and bolstering, where possible, user experiences with EOSDIS. For improving how existing and prospective users discover and access NASA data from EOSDIS we introduce our cross-archive tool: Earthdata Search. This new search and order tool further empowers users to quickly access data sets using clever and intuitive features. The Worldview data visualization tool is also discussed highlighting how many users are now performing extensive data exploration without necessarily downloading data. Also, we explore our EOSDIS data discovery and access webinars, data recipes and short tutorials, targeted technical and data publications, user profiles and and social media as additional tools and methods used for improving our outreach and communications to a diverse user community. These efforts have paid substantial dividends for our user communities by allowing us to target discipline specific community needs. The desired take-away from this presentation will be an improved understanding of how EOSDIS has approached, and in several instances achieved, removing or lowering the barriers to data access and use. As we look ahead to more complex Earth science missions, EOSDIS will continue to focus on our user communities, both broad and specialized, so that our overall data system can continue to serve the needs of science and applications users.
Exposing the Strategies that Can Reduce the Obstacles: Improving the Science User Experience
NASA Technical Reports Server (NTRS)
Lindsay, Francis E.; Brennan, Jennifer; Behnke, Jeanne; Lynnes, Chris
2017-01-01
It is now well established that pursuing generic solutions to what seem are common problems in Earth science data access and use can often lead to disappointing results for both system developers and the intended users. This presentation focuses on real-world experience of managing a large and complex data system, NASAs Earth Science Data and Information Science System (EOSDIS), whose mission is to serve both broad user communities and those in smaller niche applications of Earth science data and services. In the talk, we focus on our experiences with known data user obstacles characterizing EOSDIS approaches, including various technological techniques, for engaging and bolstering, where possible, user experiences with EOSDIS. For improving how existing and prospective users discover and access NASA data from EOSDIS we introduce our cross-archive tool: Earthdata Search. This new search and order tool further empowers users to quickly access data sets using clever and intuitive features. The Worldview data visualization tool is also discussed highlighting how many users are now performing extensive data exploration without necessarily downloading data. Also, we explore our EOSDIS data discovery and access webinars, data recipes and short tutorials, targeted technical and data publications, user profiles and social media as additional tools and methods used for improving our outreach and communications to a diverse user community. These efforts have paid substantial dividends for our user communities by allowing us to target discipline specific community needs. The desired take-away from this presentation will be an improved understanding of how EOSDIS has approached, and in several instances achieved, removing or lowering the barriers to data access and use. As we look ahead to more complex Earth science missions, EOSDIS will continue to focus on our user communities, both broad and specialized, so that our overall data system can continue to serve the needs of science and applications users.
SMOS L1C and L2 Validation in Australia
NASA Technical Reports Server (NTRS)
Rudiger, Christoph; Walker, Jeffrey P.; Kerr, Yann H.; Mialon, Arnaud; Merlin, Olivier; Kim, Edward J.
2012-01-01
Extensive airborne field campaigns (Australian Airborne Cal/val Experiments for SMOS - AACES) were undertaken during the 2010 summer and winter seasons of the southern hemisphere. The purpose of those campaigns was the validation of the Level 1c (brightness temperature) and Level 2 (soil moisture) products of the ESA-led Soil Moisture and Ocean Salinity (SMOS) mission. As SMOS is the first satellite to globally map L-band (1.4GHz) emissions from the Earth?s surface, and the first 2-dimensional interferometric microwave radiometer used for Earth observation, large scale and long-term validation campaigns have been conducted world-wide, of which AACES is the most extensive. AACES combined large scale medium-resolution airborne L-band and spectral observations, along with high-resolution in-situ measurements of soil moisture across a 50,000km2 area of the Murrumbidgee River catchment, located in south-eastern Australia. This paper presents a qualitative assessment of the SMOS brightness temperature and soil moisture products.
Automating the SMAP Ground Data System to Support Lights-Out Operations
NASA Technical Reports Server (NTRS)
Sanders, Antonio
2014-01-01
The Soil Moisture Active Passive (SMAP) Mission is a first tier mission in NASA's Earth Science Decadal Survey. SMAP will provide a global mapping of soil moisture and its freeze/thaw states. This mapping will be used to enhance the understanding of processes that link the terrestrial water, energy, and carbon cycles, and to enhance weather and forecast capabilities. NASA's Jet Propulsion Laboratory has been selected as the lead center for the development and operation of SMAP. The Jet Propulsion Laboratory (JPL) has an extensive history of successful deep space exploration. JPL missions have typically been large scale Class A missions with significant budget and staffing. SMAP represents a new area of JPL focus towards low cost Earth science missions. Success in this new area requires changes to the way that JPL has traditionally provided the Mission Operations System (MOS)/Ground Data System (GDS) functions. The operation of SMAP requires more routine operations activities and support for higher data rates and data volumes than have been achieved in the past. These activities must be addressed by a reduced operations team and support staff. To meet this challenge, the SMAP ground data system provides automation that will perform unattended operations, including automated commanding of the SMAP spacecraft.
Vision for an Open, Global Greenhouse Gas Information System (GHGIS)
NASA Astrophysics Data System (ADS)
Duren, R. M.; Butler, J. H.; Rotman, D.; Ciais, P.; Greenhouse Gas Information System Team
2010-12-01
Over the next few years, an increasing number of entities ranging from international, national, and regional governments, to businesses and private land-owners, are likely to become more involved in efforts to limit atmospheric concentrations of greenhouse gases. In such a world, geospatially resolved information about the location, amount, and rate of greenhouse gas (GHG) emissions will be needed, as well as the stocks and flows of all forms of carbon through the earth system. The ability to implement policies that limit GHG concentrations would be enhanced by a global, open, and transparent greenhouse gas information system (GHGIS). An operational and scientifically robust GHGIS would combine ground-based and space-based observations, carbon-cycle modeling, GHG inventories, synthesis analysis, and an extensive data integration and distribution system, to provide information about anthropogenic and natural sources, sinks, and fluxes of greenhouse gases at temporal and spatial scales relevant to decision making. The GHGIS effort was initiated in 2008 as a grassroots inter-agency collaboration intended to identify the needs for such a system, assess the capabilities of current assets, and suggest priorities for future research and development. We will present a vision for an open, global GHGIS including latest analysis of system requirements, critical gaps, and relationship to related efforts at various agencies, the Group on Earth Observations, and the Intergovernmental Panel on Climate Change.
Lunar Navigation Determination System - LaNDS
NASA Technical Reports Server (NTRS)
Quinn, David; Talabac, Stephen
2012-01-01
A portable comprehensive navigational system has been developed that both robotic and human explorers can use to determine their location, attitude, and heading anywhere on the lunar surface independent of external infrastructure (needs no Lunar satellite network, line of sight to the Sun or Earth, etc.). The system combines robust processing power with an extensive topographical database to create a real-time atlas (GIS Geospatial Information System) that is able to autonomously control and monitor both single unmanned rovers and fleets of rovers, as well as science payload stations. The system includes provisions for teleoperation and tele-presence. The system accepts (but does not require) inputs from a wide range of sensors. A means was needed to establish a location when the search is taken deep in a crater (looking for water ice) and out of view of Earth or any other references. A star camera can be employed to determine the user's attitude in menial space and stellar map in body space. A local nadir reference (e.g., an accelerometer that orients the nadir vector in body space) can be used in conjunction with a digital ephemeris and gravity model of the Moon to isolate the latitude, longitude, and azimuth of the user on the surface. That information can be used in conjunction with a Lunar GIS and advanced navigation planning algorithms to aid astronauts (or other assets) to navigate on the Lunar surface.
EarthCollab, building geoscience-centric implementations of the VIVO semantic software suite
NASA Astrophysics Data System (ADS)
Rowan, L. R.; Gross, M. B.; Mayernik, M. S.; Daniels, M. D.; Krafft, D. B.; Kahn, H. J.; Allison, J.; Snyder, C. B.; Johns, E. M.; Stott, D.
2017-12-01
EarthCollab, an EarthCube Building Block project, is extending an existing open-source semantic web application, VIVO, to enable the exchange of information about scientific researchers and resources across institutions. EarthCollab is a collaboration between UNAVCO, a geodetic facility and consortium that supports diverse research projects informed by geodesy, The Bering Sea Project, an interdisciplinary field program whose data archive is hosted by NCAR's Earth Observing Laboratory, and Cornell University. VIVO has been implemented by more than 100 universities and research institutions to highlight research and institutional achievements. This presentation will discuss benefits and drawbacks of working with and extending open source software. Some extensions include plotting georeferenced objects on a map, a mobile-friendly theme, integration of faceting via Elasticsearch, extending the VIVO ontology to capture geoscience-centric objects and relationships, and the ability to cross-link between VIVO instances. Most implementations of VIVO gather information about a single organization. The EarthCollab project created VIVO extensions to enable cross-linking of VIVO instances to reduce the amount of duplicate information about the same people and scientific resources and to enable dynamic linking of related information across VIVO installations. As the list of customizations grows, so does the effort required to maintain compatibility between the EarthCollab forks and the main VIVO code. For example, dozens of libraries and dependencies were updated prior to the VIVO v1.10 release, which introduced conflicts in the EarthCollab cross-linking code. The cross-linking code has been developed to enable sharing of data across different versions of VIVO, however, using a JSON output schema standardized across versions. We will outline lessons learned in working with VIVO and its open source dependencies, which include Jena, Solr, Freemarker, and jQuery and discuss future work by EarthCollab, which includes refining the cross-linking VIVO capabilities by continued integration of persistent and unique identifiers to enable automated lookup and matching across institutional VIVOs.
2018-05-08
An extensive equatorial coronal hole has rotated so that it is now facing Earth (May 2-4, 2018). The dark coronal hole extends about halfway across the solar disk. It was observed in a wavelength of extreme ultraviolet light. This magnetically open area is streaming solar wind (i.e., a stream of charged particles released from the sun) into space. When Earth enters a solar wind stream and the stream interacts with our magnetosphere, we often experience nice displays of aurora. Videos are available at https://photojournal.jpl.nasa.gov/catalog/PIA00624
KML Tours: A New Platform for Exploring and Sharing Geospatial Data
NASA Astrophysics Data System (ADS)
Barcay, D. P.; Weiss-Malik, M.
2009-12-01
Google Earth and other virtual globes have allowed millions of people to explore the world from their own home. This technology has also raised the bar for professional visualizations: enabling interactive 3D visualizations to be created from massive data-sets, and shared using the KML language. For academics and professionals alike, an engaging presentation of your geospatial data is generally expected and can be the most effective form of advertisement. To that end, we released 'Touring' in Google Earth 5.0: a new medium for cinematic expression, visualized in Google Earth and written as extensions to the KML language. In a KML tour, the author has fine-grained control over the entire visual experience: precisely moving the virtual camera through the world while dynamically modifying the content, style, position, and visibility of the displayed data. An author can synchronize audio to this experience, bringing further immersion to a visualization. KML tours can help engage a broad user-base and conveying subtle concepts that aren't immediately apparent in traditional geospatial content. Unlike a pre-rendered video, a KML Tour maintains the rich interactivity of Google Earth, allowing users to continue exploring your content, and to mash-up other content with your visualization. This session will include conceptual explanations of the Touring feature in Google Earth, the structure of the touring KML extensions, as well as examples of compelling tours.
PyrE, an interactive fire module within the NASA-GISS Earth System Model
NASA Astrophysics Data System (ADS)
Mezuman, K.; Bauer, S. E.; Tsigaridis, K.
2017-12-01
Fires directly affect the composition of the atmosphere and Earth's radiation balance by emitting a suite of reactive gases and particles. Having an interactive fire module in an Earth System Model allows us to study the natural and anthropogenic drivers, feedbacks, and interactions of biomass burning in different time periods. To do so we have developed PyrE, the NASA-GISS interactive fire emissions model. PyrE uses the flammability, ignition, and suppression parameterization proposed by Pechony and Shindell (2009), and is coupled to a burned area and surface recovery parameterization. The burned area calculation follows CLM's approach (Li et al., 2012), paired with an offline recovery scheme based on Ent's Terrestrial Biosphere Model (Ent TBM) carbon pool turnover time. PyrE is driven by environmental variables calculated by climate simulations, population density data, MODIS fire counts and LAI retrievals, as well as GFED4s emissions. Since the model development required extensive use of reference datasets, in addition to comparing it to GFED4s BA, we evaluate it by studying the effect of fires on atmospheric composition and climate. Our results show good agreement globally, with some regional differences. Finally, we quantify the present day fire radiative forcing. The development of PyrE allowed us for the first time to interactively simulate climate and fire activity with GISS-ModelE3
America at the threshold. [Contains bibliography
DOE Office of Scientific and Technical Information (OSTI.GOV)
Not Available
1991-01-01
On the 20th anniversary of the first lunar landing mission, Apollo 11, President Bush outlined a program that would put the United States on an aggressive track to return to the Moon to stay, and to land humans on Mars. The president's space policy calls for expanding human presence an activity beyond Earth orbit into the Solar System; obtaining scientific, technological and economic benefits for the American people; encouraging private sector participation in space; improving the quality of life on the Earth; strengthening national security; and promoting international cooperation in space. The Space Exploration Initiative accomplishes these goals. In Augustmore » 1989, NASA began an extensive review to summarize the technology and strategies for going back to the Moon and on to Mars. To obtain the final objective, major topical activities were defined. These activities were incremental capabilities to be achieved to fulfill the national space vision. They include: (1) moon waypoints (lunar exploration; preparation for mars; habitation; lunar based observation; fuels; energy to earth); (2) asteroids waypoints; and (3) mars waypoints. The six national space vision are (1) to increase our knowledge of solar system and beyond; (2) to rejuvenate interest in Science and engineering; (3) to refocus the US position in world leadership (from military to economic and scientific); (4) to develop technology with terrestrial application; (5) to facilitate further space exploration and commercialization; and, (6) to boost the US economy. 126 refs.« less
Prospecting for Habitable Worlds
NASA Technical Reports Server (NTRS)
Jenkins, Jon M.
2017-01-01
NASAs Kepler Mission was launched in March 2009 as NASAs first mission capable of finding Earth-size planets orbiting in the habitable zone of Sun-like stars, that range of distances for which liquid water would pool on the surface of a rocky planet. Kepler has discovered over 2200 planets and over 2200 candidate planets, many of them as small as the Earth. Forty nine of these are less than twice the size of Earth and orbit in the habitable zone of their stars, all of which are cooler and significantly smaller than the Sun.Today, Keplers amazing success seems to be a fait accompli to those unfamiliar with her history. But twenty years ago, there were no planets known outside our solar system, and few people believed it was possible to detect tiny Earth-size planets orbiting other stars. Indeed, demonstrating that the science was feasible took four proposals to NASAs Discovery Program and extensive research and laboratory demonstrations. Motivating NASA to select Kepler for launch required a confluence of the right detector technology, advances in signal processing and algorithms, and the power of supercomputing. On August 23 2015 we reported the discovery of Kepler-452b, the first small, possibly rocky planet in the habitable zone of a G2 star very similar to our own. Kepler-452b orbits its star once every 385 days in an orbit just 5 larger than that of Earth. This discovery represents an important step towards finding and characterizing small habitable worlds orbiting Sun-like stars.
Three-axis attitude determination via Kalman filtering of magnetometer data
NASA Technical Reports Server (NTRS)
Martel, Francois; Pal, Parimal K.; Psiaki, Mark L.
1988-01-01
A three-axis Magnetometer/Kalman Filter attitude determination system for a spacecraft in low-altitude Earth orbit is developed, analyzed, and simulation tested. The motivation for developing this system is to achieve light weight and low cost for an attitude determination system. The extended Kalman filter estimates the attitude, attitude rates, and constant disturbance torques. Accuracy near that of the International Geomagnetic Reference Field model is achieved. Covariance computation and simulation testing demonstrate the filter's accuracy. One test case, a gravity-gradient stabilized spacecraft with a pitch momentum wheel and a magnetically-anchored damper, is a real satellite on which this attitude determination system will be used. The application to a nadir pointing satellite and the estimation of disturbance torques represent the significant extensions contributed by this paper. Beyond its usefulness purely for attitude determination, this system could be used as part of a low-cost three-axis attitude stabilization system.
Ray, Louis L.
1992-01-01
The Great Ice Age, a recent chapter in the Earth's history, was a period of recurring widespread glaciations. During the Pleistocene Epoch of the geologic time scale, which began about a million or more years ago, mountain glaciers formed on all continents, the icecaps of Antarctica and Greenland were more extensive and thicker than today, and vast glaciers, in places as much as several thousand feet thick, spread across northern North America and Eurasia. So extensive were these glaciers that almost a third of the present land surface of the Earth was intermittently covered by ice. Even today remnants of the great glaciers cover almost a tenth of the land, indicating that conditions somewhat similar to those which produced the Great Ice Age are still operating in polar and subpolar climates.
Metadata and Service at the GFZ ISDC Portal
NASA Astrophysics Data System (ADS)
Ritschel, B.
2008-05-01
The online service portal of the GFZ Potsdam Information System and Data Center (ISDC) is an access point for all manner of geoscientific geodata, its corresponding metadata, scientific documentation and software tools. At present almost 2000 national and international users and user groups have the opportunity to request Earth science data from a portfolio of 275 different products types and more than 20 Million single data files with an added volume of approximately 12 TByte. The majority of the data and information, the portal currently offers to the public, are global geomonitoring products such as satellite orbit and Earth gravity field data as well as geomagnetic and atmospheric data for the exploration. These products for Earths changing system are provided via state-of-the art retrieval techniques. The data product catalog system behind these techniques is based on the extensive usage of standardized metadata, which are describing the different geoscientific product types and data products in an uniform way. Where as all ISDC product types are specified by NASA's Directory Interchange Format (DIF), Version 9.0 Parent XML DIF metadata files, the individual data files are described by extended DIF metadata documents. Depending on the beginning of the scientific project, one part of data files are described by extended DIF, Version 6 metadata documents and the other part are specified by data Child XML DIF metadata documents. Both, the product type dependent parent DIF metadata documents and the data file dependent child DIF metadata documents are derived from a base-DIF.xsd xml schema file. The ISDC metadata philosophy defines a geoscientific product as a package consisting of mostly one or sometimes more than one data file plus one extended DIF metadata file. Because NASA's DIF metadata standard has been developed in order to specify a collection of data only, the extension of the DIF standard consists of new and specific attributes, which are necessary for an explicit identification of single data files and the set-up of a comprehensive Earth science data catalog. The huge ISDC data catalog is realized by product type dependent tables filled with data file related metadata, which have relations to corresponding metadata tables. The product type describing parent DIF XML metadata documents are stored and managed in ORACLE's XML storage structures. In order to improve the interoperability of the ISDC service portal, the existing proprietary catalog system will be extended by an ISO 19115 based web catalog service. In addition to this development there is ISDC related concerning semantic network of different kind of metadata resources, like different kind of standardized and not-standardized metadata documents and literature as well as Web 2.0 user generated information derived from tagging activities and social navigation data.
Multispectral studies of western limb and farside maria from Galileo Earth-Moon Encounter 1
NASA Astrophysics Data System (ADS)
Williams, David A.; Greeley, Ronald; Neukum, Gerhard; Wagner, Roland; Kadel, Steven D.
1995-11-01
New visible and near-infrared multispectral images of the Moon obtained by the Galileo solid-state imaging system, along with lunar orbiter images (for crater counts), and spectral mixing analyses were used to characterize western limb and eastern farside maria and determine compositional and age relationships in selected regions. Results indicate that (1) western limb mare deposits have less variability in titanium content (<2-7 wt% TiO2) and age (2.79-3.86 Ga) than areally extensive maria on the nearside; (2) areally extensive basin-filling maria generally have higher titanium contents than smaller, crater-filling mare patches and ponds; (3) ancient maria covered by highland material (cryptomaria) may be present in the Mendel-Rydberg and South Pole-Aitken basins; and (4) maria with compositional and age variations occur in the Grimaldi, Crüger, Mendel-Rydberg, and Apollo regions. No extensive high-titanium (>6 wt% TiO2) mare basalts were observed on the western limb and farside, which may reflect the inability of such denser magmas to penetrate the thicker farside crust.
STS-65 Earth observation of Omo River Delta, Lake Turkana in Ethiopia / Kenya
NASA Technical Reports Server (NTRS)
1994-01-01
STS-65 Earth observation taken aboard Columbia, Orbiter Vehicle (OV) 102, is of Omo River Delta and Lake Turkana in Ethiopia / Kenya. The Omo Delta at the north end of Lake Turkana (Rudolph) is one of the long-term environmental study sites of the Space Shuttle program. The environmental interest in this instance is the documentation of the delta's extension into the lake. This delta extension, or aggradation, is felt to be the result of large-scale soil erosion in the recently deforested areas of Ethiopia in the watershed of the Omo River. Using digitized, rectified, machine-classified, and mensurated NASA photography, it has been determined that the Omo Delta has increased in area by approximately 400% to about 1,800 square kilometers since it was first photographed during the Gemini program in 1965. This photograph documents the long-term and increasing turbidity of Lake Turkana and the continuing delta extension southward by both the northwest and northeast distributaries of the Om
NASA Technical Reports Server (NTRS)
Stefanov, William L.; Lee, Yeon Jin; Dille, Michael
2016-01-01
Handheld astronaut photography of the Earth has been collected from the International Space Station (ISS) since 2000, making it the most temporally extensive remotely sensed dataset from this unique Low Earth orbital platform. Exclusive use of digital handheld cameras to perform Earth observations from the ISS began in 2004. Nadir viewing imagery is constrained by the inclined equatorial orbit of the ISS to between 51.6 degrees North and South latitude, however numerous oblique images of land surfaces above these latitudes are included in the dataset. While unmodified commercial off-the-shelf digital cameras provide only visible wavelength, three-band spectral information of limited quality current cameras used with long (400+ mm) lenses can obtain high quality spatial information approaching 2 meters/ground pixel resolution. The dataset is freely available online at the Gateway to Astronaut Photography of Earth site (http://eol.jsc.nasa.gov), and now comprises over 2 million images. Despite this extensive image catalog, use of the data for scientific research, disaster response, commercial applications and visualizations is minimal in comparison to other data collected from free-flying satellite platforms such as Landsat, Worldview, etc. This is due primarily to the lack of fully-georeferenced data products - while current digital cameras typically have integrated GPS, this does not function in the Low Earth Orbit environment. The Earth Science and Remote Sensing (ESRS) Unit at NASA Johnson Space Center provides training in Earth Science topics to ISS crews, performs daily operations and Earth observation target delivery to crews through the Crew Earth Observations (CEO) Facility on board ISS, and also catalogs digital handheld imagery acquired from orbit by manually adding descriptive metadata and determining an image geographic centerpoint using visual feature matching with other georeferenced data, e.g. Landsat, Google Earth, etc. The lack of full geolocation information native to the data makes it difficult to integrate astronaut photographs with other georeferenced data to facilitate quantitative analysis such as urban land cover/land use classification, change detection, or geologic mapping. The manual determination of image centerpoints is both time and labor-intensive, leading to delays in releasing geolocated and cataloged data to the public, such as the timely use of data for disaster response. The GeoCam Space project was funded by the ISS Program in 2015 to develop an on-orbit hardware and ground-based software system for increasing the efficiency of geolocating astronaut photographs from the ISS (Fig. 1). The Intelligent Robotics Group at NASA Ames Research Center leads the development of both the ground and on-orbit systems in collaboration with the ESRS Unit. The hardware component consists of modified smartphone elements including cameras, central processing unit, wireless Ethernet, and an inertial measurement unit (gyroscopes/accelerometers/magnetometers) reconfigured into a compact unit that attaches to the base of the current Nikon D4 camera - and its replacement, the Nikon D5 - and connects using the standard Nikon peripheral connector or USB port. This provides secondary, side and downward facing cameras perpendicular to the primary camera pointing direction. The secondary cameras observe calibration targets with known internal X, Y, and Z position affixed to the interior of the ISS to determine the camera pose corresponding to each image frame. This information is recorded by the GeoCam Space unit and indexed for correlation to the camera time recorded for each image frame. Data - image, EXIF header, and camera pose information - is transmitted to the ground software system (GeoRef) using the established Ku-band USOS downlink system. Following integration on the ground, the camera pose information provides an initial geolocation estimate for the individual film frame. This new capability represents a significant advance in geolocation from the manual feature-matching approach for both nadir and off-nadir viewing imagery. With the initial geolocation estimate, full georeferencing of an image is completed using the rapid tie-pointing interface in GeoRef, and the resulting data is added to the Gateway to Astronaut Photography of Earth online database in both Geotiff and Keyhole Markup Language (kml) formats. The integration of the GeoRef software component of Geocam Space into the CEO image cataloging workflow is complete, and disaster response imagery acquired by the ISS crew is now fully georeferenced as a standard data product. The on-orbit hardware component (GeoSens) is in final prototyping phase, and is on-schedule for launch to the ISS in late 2016. Installation and routine use of the Geocam Space system for handheld digital camera photography from the ISS is expected to significantly improve the usefulness of this unique dataset for a variety of public- and private-sector applications.
Initial Determination of Low Earth Orbits Using Commercial Telescopes
2008-03-01
many new technologies have significantly changed the face of private astronomy . Developments such as inexpensive but high-quality sensors, rapid... astronomy . Unpar- alleled access to quality equipment, rapid personal computing, and extensive community support enable nearly anyone to achieve feats in...other subdisciplines of astronomy , this field benefits greatly from recent advances. This project examines how modern equipment is used to track Low Earth
Making Sense of Iran: Rhetoric, Ideology, and Behavior
2011-06-01
JAMES W. FORSYTH ( Date ) _______________________________ EVERETT C. DOLMAN ( Date ) DISCLAIMER The conclusions and opinions...Abbas actually claimed to be the ―shadow of God‖ on earth . Rulers of the Qajar dynasty made no such claims, presenting the clerics an opportunity to...40 He argued that while sovereignty ultimately belongs to God, rule on earth by the Prophet Muhammad, the infallible Imams and, by extension, the
[Physical essence of erythrocytic sedimentation rate in the gravitation field of the earth].
Cherniĭ, A N
2009-01-01
The erythrocytic sedimentation rate method has been long known in medicine and extensively used in laboratory practice in tuberculosis facilities. However, many authors note that the erythrocytic sedimentation rate phenomenon has not clearly understood. By applying the total theory of relativity and quantum mechanics, the author discloses the physical essence of erythrocytic sedimentation in the gravitation field of the Earth.
The Synthetic Aperture Radar Science Data Processing Foundry Concept for Earth Science
NASA Astrophysics Data System (ADS)
Rosen, P. A.; Hua, H.; Norton, C. D.; Little, M. M.
2015-12-01
Since 2008, NASA's Earth Science Technology Office and the Advanced Information Systems Technology Program have invested in two technology evolutions to meet the needs of the community of scientists exploiting the rapidly growing database of international synthetic aperture radar (SAR) data. JPL, working with the science community, has developed the InSAR Scientific Computing Environment (ISCE), a next-generation interferometric SAR processing system that is designed to be flexible and extensible. ISCE currently supports many international space borne data sets but has been primarily focused on geodetic science and applications. A second evolutionary path, the Advanced Rapid Imaging and Analysis (ARIA) science data system, uses ISCE as its core science data processing engine and produces automated science and response products, quality assessments and metadata. The success of this two-front effort has been demonstrated in NASA's ability to respond to recent events with useful disaster support. JPL has enabled high-volume and low latency data production by the re-use of the hybrid cloud computing science data system (HySDS) that runs ARIA, leveraging on-premise cloud computing assets that are able to burst onto the Amazon Web Services (AWS) services as needed. Beyond geodetic applications, needs have emerged to process large volumes of time-series SAR data collected for estimation of biomass and its change, in such campaigns as the upcoming AfriSAR field campaign. ESTO is funding JPL to extend the ISCE-ARIA model to a "SAR Science Data Processing Foundry" to on-ramp new data sources and to produce new science data products to meet the needs of science teams and, in general, science community members. An extension of the ISCE-ARIA model to support on-demand processing will permit PIs to leverage this Foundry to produce data products from accepted data sources when they need them. This paper will describe each of the elements of the SAR SDP Foundry and describe their integration into a new conceptual approach to enable more effective use of SAR instruments.
Commercial aerospace and terrestrial applications of nickel-hydrogen batteries
NASA Astrophysics Data System (ADS)
Caldwell, Dwight B.; Coates, Dwaine K.; Fox, Chris L.; Miller, Lee E.
1996-03-01
The nickel-hydrogen battery system, used extensively in the aerospace industry to supply electrical power to earth-orbital satellites for communications, observation, and military applications, is being developed for commercial, terrestrial applications. Low-cost components, electrodes, cell designs, and battery designs are currently being tested. Catalytic hydrogen electrodes have been developed which are compatible with commercial nickel battery cost. Prismatic and spiral-wound cell designs have been built and tested. Common pressure vessel and dependent pressure vessel battery designs are also being evaluated. The nickel-hydrogen battery offers potential cycle life unequaled by any other battery system. This makes the battery ideal for many commercial and terrestrial energy storage applications such as telecommunication, remote stand-alone power systems, utility load-leveling, and other applications which require long life and a truly maintenance-free and abuse-tolerant battery system.
NASA Technical Reports Server (NTRS)
Birch, J. N.; French, R. H.
1972-01-01
An investigation was made to define experiments for collection of RFI and multipath data for application to a synchronous relay satellite/low orbiting satellite configuration. A survey of analytical models of the multipath signal was conducted. Data has been gathered concerning the existing RFI and other noise sources in various bands at VHF and UHF. Additionally, designs are presented for equipment to combat the effects of RFI and multipath: an adaptive delta mod voice system, a forward error control coder/decoder, a PN transmission system, and a wideband FM system. The performance of these systems was then evaluated. Techniques are discussed for measuring multipath and RFI. Finally, recommended data collection experiments are presented. An extensive tabulation is included of theoretical predictions of the amount of signal reflected from a rough, spherical earth.
Providing Internet Access to High-Resolution Lunar Images
NASA Technical Reports Server (NTRS)
Plesea, Lucian
2008-01-01
The OnMoon server is a computer program that provides Internet access to high-resolution Lunar images, maps, and elevation data, all suitable for use in geographical information system (GIS) software for generating images, maps, and computational models of the Moon. The OnMoon server implements the Open Geospatial Consortium (OGC) Web Map Service (WMS) server protocol and supports Moon-specific extensions. Unlike other Internet map servers that provide Lunar data using an Earth coordinate system, the OnMoon server supports encoding of data in Moon-specific coordinate systems. The OnMoon server offers access to most of the available high-resolution Lunar image and elevation data. This server can generate image and map files in the tagged image file format (TIFF) or the Joint Photographic Experts Group (JPEG), 8- or 16-bit Portable Network Graphics (PNG), or Keyhole Markup Language (KML) format. Image control is provided by use of the OGC Style Layer Descriptor (SLD) protocol. Full-precision spectral arithmetic processing is also available, by use of a custom SLD extension. This server can dynamically add shaded relief based on the Lunar elevation to any image layer. This server also implements tiled WMS protocol and super-overlay KML for high-performance client application programs.
Launch Method for Kites in Low-Wind or No-Wind Conditions
NASA Technical Reports Server (NTRS)
Bland, Geoffrey; Miles, Ted
2012-01-01
Airborne observations using lightweight camera systems are desirable for a variety of applications. This system was contemplated as a method to provide a simple remote sensing aerial platform. Kites have been successfully employed for aerial observations, but have historically required natural wind or towing to become airborne. This new method negates this requirement, and widens the applicability of kites for carrying instrumentation. Applicability is primarily limited by the space available on the ground for launching. The innovation is a method for launching kites in low-wind or no-wind conditions. This method will enable instrumentation to be carried aloft using simple (or complex) kite-based systems, to obtain observations from an aerial perspective. This technique will provide access to altitudes of 100 meters or more over any area normally suited for kite flying. The duration of any observation is dependent on wind strength; however, the initial altitude is relatively independent. The system does not require any electrical or combustion-based elements. This technology was developed to augment local-scale airborne measurement capabilities suitable for Earth science research, agricultural productivity, and environmental observations. The method represents an extension of techniques often used in aeronautical applications for launching fixed-wing aircraft, such as sailplanes, using mechanical means not incorporated in the aircraft itself. The innovation consists of an elastic cord (for propulsive force), a tether extension (optional, for additional height), and the kite (instrumentation optional). Operation of the system is accomplished by fixing the elastic cord to ground (or equivalent), attaching the cord with/or without a tether extension to the kite, tensioning the system to store energy, and releasing the kite. The kite will climb until energy is dissipated.
An astrophysical view of Earth-based metabolic biosignature gases.
Seager, Sara; Schrenk, Matthew; Bains, William
2012-01-01
Microbial life on Earth uses a wide range of chemical and energetic resources from diverse habitats. An outcome of this microbial diversity is an extensive and varied list of metabolic byproducts. We review key points of Earth-based microbial metabolism that are useful to the astrophysical search for biosignature gases on exoplanets, including a list of primary and secondary metabolism gas byproducts. Beyond the canonical, unique-to-life biosignature gases on Earth (O(2), O(3), and N(2)O), the list of metabolic byproducts includes gases that might be associated with biosignature gases in appropriate exoplanetary environments. This review aims to serve as a starting point for future astrophysical biosignature gas research.
System Engineering of Autonomous Space Vehicles
NASA Technical Reports Server (NTRS)
Watson, Michael D.; Johnson, Stephen B.; Trevino, Luis
2014-01-01
Human exploration of the solar system requires fully autonomous systems when travelling more than 5 light minutes from Earth. This autonomy is necessary to manage a large, complex spacecraft with limited crew members and skills available. The communication latency requires the vehicle to deal with events with only limited crew interaction in most cases. The engineering of these systems requires an extensive knowledge of the spacecraft systems, information theory, and autonomous algorithm characteristics. The characteristics of the spacecraft systems must be matched with the autonomous algorithm characteristics to reliably monitor and control the system. This presents a large system engineering problem. Recent work on product-focused, elegant system engineering will be applied to this application, looking at the full autonomy stack, the matching of autonomous systems to spacecraft systems, and the integration of different types of algorithms. Each of these areas will be outlined and a general approach defined for system engineering to provide the optimal solution to the given application context.
Potentially Habitable Ancient Environments in Gusev Crater, Mars
NASA Technical Reports Server (NTRS)
DesMarais, David J.
2010-01-01
Habitable environments must sustain liquid water at least intermittently and also provide both chemical building blocks and useful sources of energy for life. Observations by Spirit rover indicate that conditions have probably been too dry to sustain life, at least since the emplacement of the extensive basalts that underlie the plains around the Columbia Memorial Station landing site. Local evidence of relatively minor aqueous alteration [1] probably occurred under conditions where the activity of water was too low to sustain biological processes as we know them. In contrast, multiple bedrock units in West Spur and Husband Hill in the Columbia Hills have been extensively altered. Patterns of elemental abundances are consistent with aqueous processes involving migrating fluids [2]. Fe in several of these units has been extensively oxidized [3]. Conceivably any microbiota present during the aqueous alteration of these rocks might have obtained energy from Fe oxidation. Spirit discovered olivine-rich ultramafic rocks during her descent from Husband Hill southward into Inner Basin. Alteration of similar ultramafic rocks on Earth can yield H2 that can provide both energy and reducing power for microorganisms. Spirit's discovery of deposits rich in ferric sulfate is consistent with the aqueous dissolution and/or alteration of olivine under acidic conditions [2] such as those associated with hydrothermal activity. The oxidation of iron and sulfur that can accompany such activity can be an energy source for life. Hydrothermal systems on Earth that sustain either acidic [4] or neutral to alkaline fluids [5] have been shown to provide this energy. Collectively the observations by Spirit rover are consistent with the possibility that habitable environments existed in Gusev crater at least intermittently in the distant geologic past.
NASA Technical Reports Server (NTRS)
White, Ronald J.; Leonard, Joel I.; Srinivasan, R. Srini; Charles, John B.
1991-01-01
The purpose of NASA's Extended Duration Orbiter program is a gradual extension of the capabilities of the Space Shuttle Orbiter beyond its current 7-10 day limit on mission duration, as warranted by deepening understanding of the long-term physiological effects of weightlessness. Attention is being given to the cardiovascular problem of orthostatic tolerance loss due to its adverse effects on crew performance and health during reentry and initial readaptation to earth gravity. An account is given of the results of the application of proven mathematical models of circulatory and cardiovascular systems under microgravity conditions.
The Kepler End-to-End Model: Creating High-Fidelity Simulations to Test Kepler Ground Processing
NASA Technical Reports Server (NTRS)
Bryson, Stephen T.; Jenkins, Jon M.; Peters, Dan J.; Tenenbaum, Peter P.; Klaus, Todd C.; Gunter, Jay P.; Cote, Miles T.; Caldwell, Douglas A.
2010-01-01
The Kepler mission is designed to detect the transit of Earth-like planets around Sun-like stars by observing 100,000 stellar targets. Developing and testing the Kepler ground-segment processing system, in particular the data analysis pipeline, requires high-fidelity simulated data. This simulated data is provided by the Kepler End-to-End Model (ETEM). ETEM simulates the astrophysics of planetary transits and other phenomena, properties of the Kepler spacecraft and the format of the downlinked data. Major challenges addressed by ETEM include the rapid production of large amounts of simulated data, extensibility and maintainability.
MARCO POLO: near earth object sample return mission
NASA Astrophysics Data System (ADS)
Barucci, M. A.; Yoshikawa, M.; Michel, P.; Kawagushi, J.; Yano, H.; Brucato, J. R.; Franchi, I. A.; Dotto, E.; Fulchignoni, M.; Ulamec, S.
2009-03-01
MARCO POLO is a joint European-Japanese sample return mission to a Near-Earth Object. This Euro-Asian mission will go to a primitive Near-Earth Object (NEO), which we anticipate will contain primitive materials without any known meteorite analogue, scientifically characterize it at multiple scales, and bring samples back to Earth for detailed scientific investigation. Small bodies, as primitive leftover building blocks of the Solar System formation process, offer important clues to the chemical mixture from which the planets formed some 4.6 billion years ago. Current exobiological scenarios for the origin of Life invoke an exogenous delivery of organic matter to the early Earth: it has been proposed that primitive bodies could have brought these complex organic molecules capable of triggering the pre-biotic synthesis of biochemical compounds. Moreover, collisions of NEOs with the Earth pose a finite hazard to life. For all these reasons, the exploration of such objects is particularly interesting and urgent. The scientific objectives of MARCO POLO will therefore contribute to a better understanding of the origin and evolution of the Solar System, the Earth, and possibly Life itself. Moreover, MARCO POLO provides important information on the volatile-rich (e.g. water) nature of primitive NEOs, which may be particularly important for future space resource utilization as well as providing critical information for the security of Earth. MARCO POLO is a proposal offering several options, leading to great flexibility in the actual implementation. The baseline mission scenario is based on a launch with a Soyuz-type launcher and consists of a Mother Spacecraft (MSC) carrying a possible Lander named SIFNOS, small hoppers, sampling devices, a re-entry capsule and scientific payloads. The MSC leaves Earth orbit, cruises toward the target with ion engines, rendezvous with the target, conducts a global characterization of the target to select a sampling site, and delivers small hoppers (MINERVA type, JAXA) and SIFNOS. The latter, if added, will perform a soft landing, anchor to the target surface, and make various in situ measurements of surface/subsurface materials near the sampling site. Two surface samples will be collected by the MSC using “touch and go” manoeuvres. Two complementary sample collection devices will be used in this phase: one developed by ESA and another provided by JAXA, mounted on a retractable extension arm. After the completion of the sampling and ascent of the MSC, the arm will be retracted to transfer the sample containers into the MSC. The MSC will then make its journey back to Earth and release the re-entry capsule into the Earth’s atmosphere.
Hydrogen Isotopes in Amino Acids and Soils Offer New Potential to Study Complex Processes
NASA Astrophysics Data System (ADS)
Fogel, M. L.; Newsome, S. D.; Williams, E. K.; Bradley, C. J.; Griffin, P.; Nakamoto, B. J.
2016-12-01
Hydrogen isotopes have been analyzed extensively in the earth and biogeosciences to trace water through various environmental systems. The majority of the measurements have been made on water in rocks and minerals (inorganic) or non-exchangeable H in lipids (organic), important biomarkers that represent a small fraction of the organic molecules synthesized by living organisms. Our lab has been investigating hydrogen isotopes in amino acids and complex soil organic matter, which have traditionally been thought to be too complex to interpret owing to complications from potentially exchangeable hydrogen. For the amino acids, we show how hydrogen in amino acids originates from two sources, food and water, and demonstrate that hydrogen isotopes can be routed directly between organisms. Amino acid hydrogen isotopes may unravel cycling in extremophiles in order to discover novel biochemical pathways central to the organism. For soil organic matter, recent approaches to understanding the origin of soil organic matter are pointing towards root exudates along with microbial biomass as the source, rather than aboveground leaf litter. Having an isotope tracer in very complex, potentially exchangeable organic matter can be handled with careful experimentation. Although no new instrumentation is being used per se, extension of classes of organic matter to isotope measurements has potential to open up new doors for understanding organic matter cycling on earth and in planetary materials.
DOE Office of Scientific and Technical Information (OSTI.GOV)
List, Nanna Holmgaard, E-mail: nhl@sdu.dk; Jensen, Hans Jørgen Aagaard; Kauczor, Joanna
2015-06-28
We present a formulation of molecular response theory for the description of a quantum mechanical molecular system in the presence of a weak, monochromatic, linearly polarized electromagnetic field without introducing truncated multipolar expansions. The presentation focuses on a description of linear absorption by adopting the energy-loss approach in combination with the complex polarization propagator formulation of response theory. Going beyond the electric-dipole approximation is essential whenever studying electric-dipole-forbidden transitions, and in general, non-dipolar effects become increasingly important when addressing spectroscopies involving higher-energy photons. These two aspects are examined by our study of the near K-edge X-ray absorption fine structure ofmore » the alkaline earth metals (Mg, Ca, Sr, Ba, and Ra) as well as the trans-polyenes. In following the series of alkaline earth metals, the sizes of non-dipolar effects are probed with respect to increasing photon energies and a detailed assessment of results is made in terms of studying the pertinent transition electron densities and in particular their spatial extension in comparison with the photon wavelength. Along the series of trans-polyenes, the sizes of non-dipolar effects are probed for X-ray spectroscopies on organic molecules with respect to the spatial extension of the chromophore.« less
Passive solar/Earth sheltered office/dormitory cooling season thermal performance
NASA Astrophysics Data System (ADS)
Christian, J.
1984-06-01
Continuous detailed hourly thermal performance measurements were taken since February 1982 in and around an occupied, underground, 4000 ft(2) office/dormitory building at the Oak Ridge National Laboratory in Oak Ridge, Tennessee. This building has a number of energy saving features which were analyzed relative to their performance in a southeastern US climate and with respect to overall commercial building performance. Cooling season performance is documented, as well as effects of earth constact, interior thermal mass, an economizer cycle and interface of an efficient building envelope with a central three-ton heat pump. The Joint Institute Dormitory obtains a cooling energy savings of about 30% compared with an energy-efficient, above-grade structure and has the potential to save as much as 50%. The proper instllation of the overhand, interior thermal mass, massive supply duct system, and earth contact team up to prevent summertime overheating. From May through September, this building cost a total of $300 (at 5.7) cents/kWh) to cool and ventilate 24 hours per day. Besides thermal performance of the building envelope, extensive comfort data was taken illustrating that at least 90% of the occupants are comfortable all of the time according to the PMV measurements.
Hart, Robert J.; Vaughan, R. Greg; McDougall, Kristin; Wojtowicz, Todd; Thenkenbail, Prasad
2017-06-29
The U.S. Geological Survey’s Flagstaff Science Campus is focused on interdisciplinary study of the Earth and solar system, and has the scientific expertise to detect early environmental changes and provide strategies to minimize possible adverse effects on humanity. The Flagstaff Science Campus (FSC) is located in Flagstaff, Arizona, which is situated in the northern part of the State, home to a wide variety of landscapes and natural resources, including (1) young volcanoes in the San Francisco Volcanic Field, (2) the seven ecological life zones of the San Francisco Peaks, (3) the extensive geologic record of the Colorado Plateau and Grand Canyon, (4) the Colorado River and its perennial, ephemeral, and intermittent tributaries, and (5) a multitude of canyons, mountains, arroyos, and plains. More than 200 scientists, technicians, and support staff provide research, monitoring, and technical advancements in planetary geology and mapping, biology and ecology, Earth-based geology, hydrology, and changing climate and landscapes. Scientists at the FSC work in collaboration with multiple State, Federal, Tribal, municipal, and academic partners to address regional, national, and global environmental issues, and provide scientific outreach to the general public.
Analogs from LEO: Mapping Earth Observations to Planetary Science & Astrobiology. (Invited)
NASA Astrophysics Data System (ADS)
Hand, K. P.; Painter, T. H.
2010-12-01
If, as Charles Lyell articulated ‘the present is the key to the past’ for terrestrial geology, then perhaps by extension the Earth, our planet, is the key to understanding other planets. This is the basic premise behind planetary analogs. Many planetary science missions, however, utilize orbiters and are therefore constrained to remote sensing. This is the reverse of how we developed our understanding of Earth’s environments; remote sensing is a relatively new tool for understanding environments and processes on Earth. Here we present several cases and comparisons between Earth’s cryosphere and icy worlds of the outer Solar System (e.g. Europa, Titan, and Enceladus), where much of our knowledge is limited to remote observations (the sole exception being the Huygens probe to Titan). Three regions are considered: glaciers in the Sierra Nevada, the permafrost lakes of Alaska’s North Slope, and spreading centers of the ocean floor. Two key issues are examined: 1) successes and limitations for understanding processes that shape icy worlds, and 2) successes and limitations for assessing the habitability of icy worlds from orbit. Finally, technological considerations for future orbiting mission to icy worlds are presented.
Methodology for the systems engineering process. Volume 2: Technical parameters
NASA Technical Reports Server (NTRS)
Nelson, J. H.
1972-01-01
A scheme based on starting the logic networks from the development and mission factors that are of primary concern in an aerospace system is described. This approach required identifying the primary states (design, design verification, premission, mission, postmission), identifying the attributes within each state (performance capability, survival, evaluation, operation, etc), and then developing the generic relationships of variables for each branch. To illustrate this concept, a system was used that involved a launch vehicle and payload for an earth orbit mission. Examination showed that this example was sufficient to illustrate the concept. A more complicated mission would follow the same basic approach, but would have more extensive sets of generic trees and more correlation points between branches. It has been shown that in each system state (production, test, and use), a logic could be developed to order and classify the parameters involved in the translation from general requirements to specific requirements for system elements.
Field spectroscopy sampling strategies for improved measurement of Earth surface reflectance
NASA Astrophysics Data System (ADS)
Mac Arthur, A.; Alonso, L.; Malthus, T. J.; Moreno, J. F.
2013-12-01
Over the last two decades extensive networks of research sites have been established to measure the flux of carbon compounds and water vapour between the Earth's surface and the atmosphere using eddy covariance (EC) techniques. However, contributing Earth surface components cannot be determined and (as the ';footprints' are spatially constrained) these measurements cannot be extrapolated to regional cover using this technique. At many of these EC sites researchers have been integrating spectral measurements with EC and ancillary data to better understand light use efficiency and carbon dioxide flux. These spectroscopic measurements could also be used to assess contributing components and provide support for imaging spectroscopy, from airborne or satellite platforms, which can provide unconstrained spatial cover. Furthermore, there is an increasing interest in ';smart' database and information retrieval systems such as that proposed by EcoSIS and OPTIMISE to store, analyse, QA and merge spectral and biophysical measurements and provide information to end users. However, as Earth surfaces are spectrally heterogeneous and imaging and field spectrometers sample different spatial extents appropriate field sampling strategies require to be adopted. To sample Earth surfaces spectroscopists adopt either single; random; regular grid; transect; or 'swiping' point sampling strategies, although little comparative work has been carried out to determine the most appropriate approach; the work by Goetz (2012) is a limited exception. Mac Arthur et al (2012) demonstrated that, for two full wavelength (400 nm to 2,500 nm) field spectroradiometers, the measurement area sampled is defined by each spectroradiometer/fore optic system's directional response function (DRF) rather than the field-of-view (FOV) specified by instrument manufacturers. Mac Arthur et al (2012) also demonstrated that each reflecting element within the sampled area was not weighted equally in the integrated measurement recorded. There were non-uniformities of spectral response with the spectral ';weighting' per wavelength interval being positionally dependent and unique to each spectroradiometer/fore optic system investigated. However, Mac Arthur et al (2012) did not provide any advice on how to compensate for these systematic errors or advise on appropriate sampling strategies. The work reported here will provide the first systematic study of the effect of field spectroscopy sampling strategies for a range of different Earth surface types. Synthetic Earth surface hyperspectral data cubes for each surface type were generated and convolved with a range of the spectrometer/fore optic system directional response functions generated by Mac Arthur et al 2013, to simulate spectroscopic measurements of Earth surfaces. This has enabled different field sampling strategies to be directly compared and their suitability for each measurement purpose and surface type to be assessed and robust field spectroscopy sampling strategy recommendations to be made. This will be particularly of interest to the carbon and water vapour flux communities and assist the development of sampling strategies for field spectroscopy from rotary-wing Unmanned Aerial Vehicles, which will aid acquiring measurements in the spatial domain, and generally further the use of field spectroscopy for quantitative Earth observation.
Exploration Medical System Demonstration Project
NASA Technical Reports Server (NTRS)
Chin, D. A.; McGrath, T. L.; Reyna, B.; Watkins, S. D.
2011-01-01
A near-Earth Asteroid (NEA) mission will present significant new challenges including hazards to crew health created by exploring a beyond low earth orbit destination, traversing the terrain of asteroid surfaces, and the effects of variable gravity environments. Limited communications with ground-based personnel for diagnosis and consultation of medical events require increased crew autonomy when diagnosing conditions, creating treatment plans, and executing procedures. Scope: The Exploration Medical System Demonstration (EMSD) project will be a test bed on the International Space Station (ISS) to show an end-to-end medical system assisting the Crew Medical Officers (CMO) in optimizing medical care delivery and medical data management during a mission. NEA medical care challenges include resource and resupply constraints limiting the extent to which medical conditions can be treated, inability to evacuate to Earth during many mission phases, and rendering of medical care by a non-clinician. The system demonstrates the integration of medical technologies and medical informatics tools for managing evidence and decision making. Project Objectives: The objectives of the EMSD project are to: a) Reduce and possibly eliminate the time required for a crewmember and ground personnel to manage medical data from one application to another. b) Demonstrate crewmember's ability to access medical data/information via a software solution to assist/aid in the treatment of a medical condition. c) Develop a common data management architecture that can be ubiquitously used to automate repetitive data collection, management, and communications tasks for all crew health and life sciences activities. d) Develop a common data management architecture that allows for scalability, extensibility, and interoperability of data sources and data users. e) Lower total cost of ownership for development and sustainment of peripheral hardware and software that use EMSD for data management f) Provide better crew health via the reduction in crew errors, crew time, and ground time.
The UK Earth System Models Marine Biogeochemical Evaluation Toolkit, BGC-val
NASA Astrophysics Data System (ADS)
de Mora, Lee
2017-04-01
The Biogeochemical Validation toolkit, BGC-val, is a model and grid independent python-based marine model evaluation framework that automates much of the validation of the marine component of an Earth System Model. BGC-val was initially developed to be a flexible and extensible system to evaluate the spin up of the marine UK Earth System Model (UKESM). However, the grid-independence and flexibility means that it is straightforward to adapt the BGC-val framework to evaluate other marine models. In addition to the marine component of the UKESM, this toolkit has been adapted to compare multiple models, including models from the CMIP5 and iMarNet inter-comparison projects. The BGC-val toolkit produces multiple levels of analysis which are presented in a simple to use interactive html5 document. Level 1 contains time series analyses, showing the development over time of many important biogeochemical and physical ocean metrics, such as the Global primary production or the Drake passage current. The second level of BGC-val is an in-depth spatial analyses of a single point in time. This is a series of point to point comparison of model and data in various regions, such as a comparison of Surface Nitrate in the model vs data from the world ocean atlas. The third level analyses are specialised ad-hoc packages to go in-depth on a specific question, such as the development of Oxygen minimum zones in the Equatorial Pacific. In additional to the three levels, the html5 document opens with a Level 0 table showing a summary of the status of the model run. The beta version of this toolkit is available via the Plymouth Marine Laboratory Gitlab server and uses the BSD 3 clause license.
Properties of Earth's temporarily-captured flybys
NASA Astrophysics Data System (ADS)
Fedorets, Grigori; Granvik, Mikael
2014-11-01
In addition to the Moon, a population of small temporarily-captured NEOs is predicted to orbit the Earth. The definition of a natural Earth satellite is that it is on an elliptic geocentric orbit within 0.03 au from the Earth. The population is further divided into temporarily-captured orbiters (TCOs, or minimoons, making at least one full revolution around the Earth in a coordinate system co-rotating with the Sun) and temporarily-captured flybys (TCFs) which fail to make a full revolution, but are temporarily on an elliptic orbit around the Earth. Only one minimoon has been discovered to date, but it is expected that next generation surveys will be able to detect these objects regularly.Granvik et al. (2012) performed an extensive analysis of the behaviour of these temporarily-captured objects. One of the main results was that at any given moment there is at least one 1-meter-diameter minimoon in orbit around the Earth. However, the results of Granvik et al. (2012) raised questions considering the NES population such as the bimodality of the capture duration distribution and a distinctive lack of test particles within Earth's Hill sphere, which requires investigating the statistical properties also of the TCF population.In this work we confirm the population characteristics for minimoons described by Granvik et al. (2012), and extend the analysis to TCFs. For the calculations we use a Bulirsch-Stoer integrator implemented in the OpenOrb software package (Granvik et al. 2009). We study, e.g., the capture statistics, residence-time distributions, and steady-state properties of TCFs. Our preliminary results indicate that TCFs may be suitable targets for asteroid-redirect missions. More detailed knowledge of the TCF population will also improve our understanding of the link between temporarily-captured objects and NEOs in general.References: Granvik et al. (2009) MPS 44(12), 1853-1861; Granvik et al. (2012) Icarus 218, 262-277.
NASA Technical Reports Server (NTRS)
Hoehler, Tori M.
2010-01-01
The remarkable challenges and possibilities of the coming few decades will compel the biogeochemical and astrobiological sciences to characterize the interactions between biology and its environment in a fundamental, mechanistic, and quantitative fashion. The clear need for integrative and scalable biology-environment models is exemplified in the Earth sciences by the challenge of effectively addressing anthropogenic global change, and in the space sciences by the challenge of mounting a well-constrained yet sufficiently adaptive and inclusive search for life beyond Earth. Our understanding of the life-planet interaction is still, however, largely empirical. A variety of approaches seek to move from empirical to mechanistic descriptions. One approach focuses on the relationship between biology and energy, which is at once universal (all life requires energy), unique (life manages energy flow in a fashion not seen in abiotic systems), and amenable to characterization and quantification in thermodynamic terms. Simultaneously, a focus on energy flow addresses a critical point of interface between life and its geological, chemical, and physical environment. Characterizing and quantifying this relationship for life on Earth will support the development of integrative and predictive models for biology-environment dynamics. Understanding this relationship at its most fundamental level holds potential for developing concepts of habitability and biosignatures that can optimize astrobiological exploration strategies and are extensible to all life.
Jenkins, J M; Doyle, L R; Cullers, D K
1996-02-01
The photometric detection of extrasolar planets by transits in eclipsing binary systems can be significantly improved by cross-correlating the observational light curves with synthetic models of possible planetary transit features, essentially a matched filter approach. We demonstrate the utility and application of this transit detection algorithm for ground-based detections of terrestrial-sized (Earth-to-Neptune radii) extrasolar planets in the dwarf M-star eclipsing binary system CM Draconis. Preliminary photometric observational data of this system demonstrate that the observational noise is well characterized as white and Gaussian at the observational time steps required for precision photometric measurements. Depending on planet formation scenarios, terrestrial-sized planets may form quite close to this low-luminosity system. We demonstrate, for example, that planets as small as 1.4 Earth radii with periods on the order of a few months in the CM Draconis system could be detected at the 99.9% confidence level in less than a year using 1-m class telescopes from the ground. This result contradicts commonly held assumptions limiting present ground-based efforts to, at best, detections of gas giant planets after several years of observation. This method can be readily extended to a number of other larger star systems with the utilization of larger telescopes and longer observing times. Its extension to spacecraft observations should also allow the determination of the presence of terrestrial-sized planets in nearly 100 other known eclipsing binary systems.
NASA Technical Reports Server (NTRS)
Jenkins, J. M.; Doyle, L. R.; Cullers, D. K.
1996-01-01
The photometric detection of extrasolar planets by transits in eclipsing binary systems can be significantly improved by cross-correlating the observational light curves with synthetic models of possible planetary transit features, essentially a matched filter approach. We demonstrate the utility and application of this transit detection algorithm for ground-based detections of terrestrial-sized (Earth-to-Neptune radii) extrasolar planets in the dwarf M-star eclipsing binary system CM Draconis. Preliminary photometric observational data of this system demonstrate that the observational noise is well characterized as white and Gaussian at the observational time steps required for precision photometric measurements. Depending on planet formation scenarios, terrestrial-sized planets may form quite close to this low-luminosity system. We demonstrate, for example, that planets as small as 1.4 Earth radii with periods on the order of a few months in the CM Draconis system could be detected at the 99.9% confidence level in less than a year using 1-m class telescopes from the ground. This result contradicts commonly held assumptions limiting present ground-based efforts to, at best, detections of gas giant planets after several years of observation. This method can be readily extended to a number of other larger star systems with the utilization of larger telescopes and longer observing times. Its extension to spacecraft observations should also allow the determination of the presence of terrestrial-sized planets in nearly 100 other known eclipsing binary systems.
Multi-temporal mapping of a large, slow-moving earth flow for kinematic interpretation
Guerriero, Luigi; Coe, Jeffrey A.; Revellino, Paola; Guadagno, Francesco M.
2014-01-01
Periodic movement of large, thick landslides on discrete basal surfaces produces modifications of the topographic surface, creates faults and folds, and influences the locations of springs, ponds, and streams (Baum, et al., 1993; Coe et al., 2009). The geometry of the basal-slip surface, which can be controlled by geological structures (e.g., fold axes, faults, etc.; Revellino et al., 2010; Grelle et al., 2011), and spatial variation in the rate of displacement, are responsible for differential deformation and kinematic segmentation of the landslide body. Thus, large landslides are often composed of several distinct kinematic elements. Each element represents a discrete kinematic domain within the main landslide that is broadly characterized by stretching (extension) of the upper part of the landslide and shortening (compression) near the landslide toe (Baum and Fleming, 1991; Guerriero et al., in review). On the basis of this knowledge, we used photo interpretive and GPS field mapping methods to map structures on the surface of the Montaguto earth flow in the Apennine Mountains of southern Italy at a scale of 1:6,000. (Guerriero et al., 2013a; Fig.1). The earth flow has been periodically active since at least 1954. The most extensive and destructive period of activity began on April 26, 2006, when an estimated 6 million m3 of material mobilized, covering and closing Italian National Road SS90, and damaging residential structures (Guerriero et al., 2013b). Our maps show the distribution and evolution of normal faults, thrust faults, strike-slip faults, flank ridges, and hydrological features at nine different dates (October, 1954; June, 1976; June, 1991; June, 2003; June, 2005; May, 2006; October, 2007; July, 2009; and March , 2010) between 1954 and 2010. Within the earth flow we recognized several kinematic elements and associated structures (Fig.2a). Within each kinematic element (e.g. the earth flow neck; Fig.2b), the flow velocity was highest in the middle, and lowest in the upper and lower parts. As the velocity of movement initiated and increased, stretching of the earth flow body induced the formation of normal faults. Conversely, decreasing velocity and shortening of the earth flow induced the formation of thrust faults. A zone with relatively few structures, bounded by strike-slip faults, was located between stretching and shortening areas. These kinematic elements indicate that the overall earth flow was actually composed of numerous linked internal earth flows, with each internal flow having a distinct pattern of structures representative of stretching and shortening (Guerriero et al., in review). These observations indicated that the spatial variation in movement velocity associated with each internal earth flow, mimicked the pattern of movement for the overall earth flow. That is, the earth flow displayed a self-similar pattern at different scales. Furthermore, the presence of other structures such as back-tilted surfaces, flank-ridges, and hydrological elements provide specific information about the shape of the basal topographic surface. Our multi-temporal maps provided a basis for interpretation of the long-term kinematic evolution of the earth flow and the influence of the basal-slip surface on the earth flow movement. Our maps showed that main faults remained stationary through time, despite extensive mobilization and movement of material. This observation indicated that the slip-surface has remained relatively stationary since at least 1954.
Lewis Research Center earth resources program
NASA Technical Reports Server (NTRS)
Mark, H.
1972-01-01
The Lewis Research Center earth resources program efforts are in the areas of: (1) monitoring and rapid evaluation of water quality; (2) determining ice-type and ice coverage distribution to aid operations in a possible extension of the Great Lakes ice navigation and shipping season; (3) monitoring spread of crop viruses; and (4) extent of damage to strip mined areas as well as success of efforts to rehabilitate such areas for agriculture.
Water-resources activities of the U.S. Geological Survey in Texas; fiscal years 1982-84
Grozier, R.U.; Land, L.F.
1985-01-01
Providing earth-science information through an extensive publications program and a network of public access points. Along with its continuing commitment to meet the growing and changing earthscience information needs of the Nation, the USGS remains dedicated to its original mission to collect, analyze, interpret, publish, and disseminate information about the natural resources of the Nation providing "earth science in the public service."
Water-resources activities of the U.S. Geological Survey in Texas; fiscal year 1987
Mitchell, Alicia A.
1988-01-01
Providing earth-science information through an extensive publications program and a network of public access points. Along with its continuing commitment to meet the growing and changing earthscience information needs of the Nation, the USGS remains dedicated to its original mission to collect, analyze, interpret, publish, and disseminate information about the natural resources of the Nation providing "earth science in the public service."
Space operations center: Shuttle interaction study extension, executive summary
NASA Technical Reports Server (NTRS)
1982-01-01
The Space Operations Center (SOC) is conceived as a permanent facility in low Earth orbit incorporating capabilities for space systems construction; space vehicle assembly, launching, recovery and servicing; and the servicing of co-orbiting satellites. The Shuttle Transportation System is an integral element of the SOC concept. It will transport the various elements of the SOC into space and support the assembly operation. Subsequently, it will regularly service the SOC with crew rotations, crew supplies, construction materials, construction equipment and components, space vehicle elements, and propellants and spare parts. The implications to the SOC as a consequence of the Shuttle supporting operations are analyzed. Programmatic influences associated with propellant deliveries, spacecraft servicing, and total shuttle flight operations are addressed.
Using the Earth as an Effective Model for Integrating Space Science Into Education Outreach Programs
NASA Astrophysics Data System (ADS)
Morris, P. A.; Allen, J.; Galindo, C.; McKay, G.; Obot, V.; Reiff, P.
2005-05-01
Our methods of teaching Earth and space science as two disciplines do not represent the spirit of earlier scientists such as Aristotle, da Vinci, and Galileo. We need to re-evaluate these methods and take advantage of the excitement created in the general public over the recent space science exploration programs. The information that we are obtaining from both the Mars missions and Cassini-Huygens focuses on interpreting geomorphology, mineral compositions and gas identification based on Earth as a baseline for data evaluation. This type of evaluation is an extension of Hutton's 18th century principle of Uniformitarianism, the present is the key to the past, or Earth is the key for understanding extraterrestrial bodies. Geomorphological examples are volcanic activity, meteoritic impacts, and evidence of water altering surface features. The Hawaiian, or shield, type volcanoes are analogues for Olympus Mons and the other volcanoes on Mars. Other examples include comparing sand dunes on Earth with possible Martian dunes, known stream patterns on Earth with potential stream patterns on Mars, and even comparing meteoritic impact features on Mars, the Earth, Moon and Mercury. All of these comparisons have been developed into inquiry-based activities and are available through NASA publications. Each of these activities is easily adapted to emphasize either Earth science or space science or both. Beyond geomorphology, solar storms are an excellent topic for integrating Earth and space science. Solar storms are traditionally part of space science studies, but most students do not understand their effect on Earth or the intense effects they could have on humans, whether traveling through space or exploring the surfaces of the Moon or Mars. Effects are not only limited to space travel and other planetary surfaces but also include Earth's magnetosphere, which in turn, affect radio transmission and potentially climate. Like geomorphology courses, there are extensive NASA programs available via either the Internet or CD (e.g., those distributed by P. Reiff, Rice University) that provide inquiry-based activities for students. There is great potential to share the connections of Earth and space science by using NASA developed education materials. The materials can be adapted for the classroom, after school programs, family outreach events, and summer science enrichment programs.
Boron Enrichment in Martian Clay
Nagashima, Kazuhide; Freeland, Stephen J.
2013-01-01
We have detected a concentration of boron in martian clay far in excess of that in any previously reported extra-terrestrial object. This enrichment indicates that the chemistry necessary for the formation of ribose, a key component of RNA, could have existed on Mars since the formation of early clay deposits, contemporary to the emergence of life on Earth. Given the greater similarity of Earth and Mars early in their geological history, and the extensive disruption of Earth's earliest mineralogy by plate tectonics, we suggest that the conditions for prebiotic ribose synthesis may be better understood by further Mars exploration. PMID:23762242
NASA Astrophysics Data System (ADS)
Lauer, Axel; Jones, Colin; Eyring, Veronika; Evaldsson, Martin; Hagemann, Stefan; Mäkelä, Jarmo; Martin, Gill; Roehrig, Romain; Wang, Shiyu
2018-01-01
The performance of updated versions of the four earth system models (ESMs) CNRM, EC-Earth, HadGEM, and MPI-ESM is assessed in comparison to their predecessor versions used in Phase 5 of the Coupled Model Intercomparison Project. The Earth System Model Evaluation Tool (ESMValTool) is applied to evaluate selected climate phenomena in the models against observations. This is the first systematic application of the ESMValTool to assess and document the progress made during an extensive model development and improvement project. This study focuses on the South Asian monsoon (SAM) and the West African monsoon (WAM), the coupled equatorial climate, and Southern Ocean clouds and radiation, which are known to exhibit systematic biases in present-day ESMs. The analysis shows that the tropical precipitation in three out of four models is clearly improved. Two of three updated coupled models show an improved representation of tropical sea surface temperatures with one coupled model not exhibiting a double Intertropical Convergence Zone (ITCZ). Simulated cloud amounts and cloud-radiation interactions are improved over the Southern Ocean. Improvements are also seen in the simulation of the SAM and WAM, although systematic biases remain in regional details and the timing of monsoon rainfall. Analysis of simulations with EC-Earth at different horizontal resolutions from T159 up to T1279 shows that the synoptic-scale variability in precipitation over the SAM and WAM regions improves with higher model resolution. The results suggest that the reasonably good agreement of modeled and observed mean WAM and SAM rainfall in lower-resolution models may be a result of unrealistic intensity distributions.
Our Changing Climate: A Brand New Way to Study Climate Science
NASA Astrophysics Data System (ADS)
Brey, J. A.; Kauffman, C.; Geer, I.; Nugnes, K. A.; Mills, E. W.
2014-12-01
Earth's climate is inherently variable, but is currently changing at rates unprecedented in recent Earth history. Human activity plays a major role in this change and is projected to do so well into the future. This is the stance taken in Our Changing Climate, the brand new climate science ebook from the American Meteorological Society (AMS). Our Changing Climate investigates Earth's climate system, explores humans' impact on it, and identifies actions needed in response to climate change. Released in August 2014, Our Changing Climate is the result of a year's worth of intensive research and writing, incorporating the latest scientific understandings of Earth's climate system from reports such as IPCC AR5 and the Third National Climate Assessment. To encourage additional exploration of climate science information, scientific literature, from which chapter content was derived, is cited at the conclusion of each chapter. In addition, Topic In Depth sections appear throughout each chapter and lead to more extensive information related to various topics. For example, a Topic In Depth in Chapter 11 describes the effect of climate extremes on ranching enterprises in Nebraska. Climate science is multi-disciplinary and therefore Our Changing Climate covers a breadth of topics. From understanding basic statistics and geospatial tools used to investigate Earth's climate system to examining the psychological and financial reasons behind climate change denial, the AMS believes that a multi-disciplinary approach is the most effective way to increase climate literacy. Our Changing Climate is part of the AMS Climate Studies course which is intended for undergraduate-level students. Other course materials include an eInvestigations Manual and access to the RealTime Climate Portal, both of which provide weekly activities corresponding to that week's chapter content. The RealTime Climate Portal also has links to climate data as well as societal interactions and climate policy websites to spur further interest. Faculty support materials are also provided. AMS Climate Studies has been licensed by 130 institutions since Fall 2010. Our Changing Climate reveals the impact that each of us has on the climate. With this understanding come choices and actions for a more sustainable future.
Hydrogen isotopic fractionation during crystallization of the terrestrial magma ocean
NASA Astrophysics Data System (ADS)
Pahlevan, K.; Karato, S. I.
2016-12-01
Models of the Moon-forming giant impact extensively melt and partially vaporize the silicate Earth and deliver a substantial mass of metal to the Earth's core. The subsequent evolution of the terrestrial magma ocean and overlying vapor atmosphere over the ensuing 105-6 years has been largely constrained by theoretical models with remnant signatures from this epoch proving somewhat elusive. We have calculated equilibrium hydrogen isotopic fractionation between the magma ocean and overlying steam atmosphere to determine the extent to which H isotopes trace the evolution during this epoch. By analogy with the modern silicate Earth, the magma ocean-steam atmosphere system is often assumed to be chemically oxidized (log fO2 QFM) with the dominant atmospheric vapor species taken to be water vapor. However, the terrestrial magma ocean - having held metallic droplets in suspension - may also exhibit a much more reducing character (log fO2 IW) such that equilibration with the overlying atmosphere renders molecular hydrogen the dominant H-bearing vapor species. This variable - the redox state of the magma ocean - has not been explicitly included in prior models of the coupled evolution of the magma ocean-steam atmosphere system. We find that the redox state of the magma ocean influences not only the vapor speciation and liquid-vapor partitioning of hydrogen but also the equilibrium isotopic fractionation during the crystallization epoch. The liquid-vapor isotopic fractionation of H is substantial under reducing conditions and can generate measurable D/H signatures in the crystallization products but is largely muted in an oxidizing magma ocean and steam atmosphere. We couple equilibrium isotopic fractionation with magma ocean crystallization calculations to forward model the behavior of hydrogen isotopes during this epoch and find that the distribution of H isotopes in the silicate Earth immediately following crystallization represents an oxybarometer for the terrestrial magma ocean. Whether such endogenous isotopic heterogeneity would survive as an observable signature in the modern silicate Earth is an open question.
MarcoPolo-R: Mission and Spacecraft Design
NASA Astrophysics Data System (ADS)
Peacocke, L.; Kemble, S.; Chapuy, M.; Scheer, H.
2013-09-01
The MarcoPolo-R mission is a candidate for the European Space Agency's medium-class Cosmic Vision programme, with the aim to obtain a 100 g sample of asteroid surface material and return it safely to the Earth. Astrium is one of two industrial contractors currently studying the mission to Phase A level, and the team has been working on the mission and spacecraft design since January 2012. Asteroids are some of the most primitive bodies in our solar system and are key to understanding the formation of the Earth, Sun and other planetary bodies. A returned sample would allow extensive analyses in the large laboratory-sized instruments here on Earth that are not possible with in-situ instruments. This analysis would also increase our understanding of the composition and structure of asteroids, and aid in plans for asteroid deflection techniques. In addition, the mission would be a valuable precursor for missions such as Mars Sample Return, demonstrating a high speed Earth re-entry and hard landing of an entry capsule. Following extensive mission analysis of both the baseline asteroid target 1996 FG3 and alternatives, a particularly favourable trajectory was found to the asteroid 2008 EV5 resulting in a mission duration of 4.5 to 6 years. In October 2012, the MarcoPolo-R baseline target was changed to 2008 EV5 due to its extremely primitive nature, which may pre-date the Sun. This change has a number of advantages: reduced DeltaV requirements, an orbit with a more benign thermal environment, reduced communications distances, and a reduced complexity propulsion system - all of which simplify the spacecraft design significantly. The single spacecraft would launch between 2022 and 2024 on a Soyuz-Fregat launch vehicle from Kourou. Solar electric propulsion is necessary for the outward and return transfers due to the DeltaV requirements, to minimise propellant mass. Once rendezvous with the asteroid is achieved, an observation campaign will begin to characterise the asteroid properties and map the surface in detail. Five potential sampling sites will be selected and closely observed in a local characterisation phase, leading to a single preferred sampling site being identified. The baseline instruments are a Narrow Angle Camera, a Mid-Infrared Spectrometer, a Visible Near-Infrared Spectrometer, a Radio Science Experiment, and a Close-up Camera. For the sampling phase, the spacecraft will perform a touch-and-go manoeuvre. A boom with a sampling mechanism at the end will be deployed, and the spacecraft will descend using visual navigation to touch the asteroid for some seconds. The rotary brush sampling mechanism will be activated on touchdown to obtain a good quality sample comprising regolith dust and pebbles. Low touchdown velocities and collision avoidance are critical at this point to prevent damage to the spacecraft and solar arrays. The spacecraft will then move away, returning to a safe orbit, and the sample will be transferred to an Earth Re-entry Capsule. After a final post-sampling characterisation campaign, the spacecraft will perform the return transfer to Earth. The Earth Re-entry Capsule will be released to directly enter the Earth's atmosphere, and is designed to survive a hard landing with no parachute deceleration. Once recovered, the asteroid sample would be extracted in a sample curation facility in preparation for the full analysis campaign. This presentation will describe Astrium's MarcoPolo-R mission and spacecraft design, with a focus on the innovative aspects of the design.
Aromatic, Alphatic, Enigmatic: The Chemistry of Titan
NASA Astrophysics Data System (ADS)
Horst, Sarah
2017-10-01
The extraordinary complexity of Titan’s atmospheric chemistry far surpasses that of any other solar system atmosphere. With its thick N2 atmosphere and stable bodies of liquid on its surface, Titan also possesses many physical processes that are similar to those that occur on Earth. The connection between Titan’s surface and atmosphere is unique in our solar system; atmospheric chemistry produces materials that are deposited on the surface and subsequently altered by surface-atmosphere interactions such as aeolian and fluvial processes resulting in the formation of extensive dune fields and expansive lakes and seas. Titan’s atmosphere is favorable for organic haze formation, which combined with the presence of some oxygen-bearing molecules indicates that Titan’s atmosphere may produce molecules of prebiotic interest. The combination of organics and liquid, in the form of water in a subsurface ocean and methane/ethane in the surface lakes and seas, means that Titan may be the ideal place in the solar system to test ideas about habitability, prebiotic chemistry, and the ubiquity and diversity of life in the universe. I will review our current understanding of chemistry on Titan forged from the powerful combination of Earth-based observations, remote sensing and in situ spacecraft measurements, laboratory experiments, and models. I will conclude with some of the questions that remain after Cassini-Huygens.
Use and Protection of GPS Sidelobe Signals for Enhanced Navigation Performance in High Earth Orbit
NASA Technical Reports Server (NTRS)
Parker, Joel J. K.; Valdez, Jennifer E.; Bauer, Frank H.; Moreau, Michael C.
2016-01-01
The application of the Global Positioning System (GPS) for navigation of spacecraft in High and Geosynchronous Earth Orbit (HEO/GEO) has crossed a threshold and is now being employed in operational missions. Utilizing advanced GPS receivers optimized for these missions, space users have made extensive use of the sidelobe transmissions from the GPS satellites to realize navigation performance that far exceeds that predicted by pre-launch simulations. Unfortunately, the official specification for the GPS Space Service Volume (SSV), developed in 2006, assumes that only signals emanating from the main beam of the GPS transmit antenna are useful for navigation, which greatly under-estimates the number of signals available for navigation purposes. As a result, future high-altitude space users may be vulnerable to any GPS design changes that suppress the sidelobe transmissions, beginning with Block III space vehicles (SVs) 11-32. This paper presents proposed changes to the GPS system SSV requirements, as informed by data from recent experiments in the SSV and new mission applications that are enabled by GPS navigation in HEO/GEO regimes. The NASA/NOAA GOES-R series satellites are highlighted as an example of a mission that relies on this currently-unspecified GPS system performance to meet mission requirements.
Mission Architecture Comparison for Human Lunar Exploration
NASA Technical Reports Server (NTRS)
Geffre, Jim; Robertson, Ed; Lenius, Jon
2006-01-01
The Vision for Space Exploration outlines a bold new national space exploration policy that holds as one of its primary objectives the extension of human presence outward into the Solar System, starting with a return to the Moon in preparation for the future exploration of Mars and beyond. The National Aeronautics and Space Administration is currently engaged in several preliminary analysis efforts in order to develop the requirements necessary for implementing this objective in a manner that is both sustainable and affordable. Such analyses investigate various operational concepts, or mission architectures , by which humans can best travel to the lunar surface, live and work there for increasing lengths of time, and then return to Earth. This paper reports on a trade study conducted in support of NASA s Exploration Systems Mission Directorate investigating the relative merits of three alternative lunar mission architecture strategies. The three architectures use for reference a lunar exploration campaign consisting of multiple 90-day expeditions to the Moon s polar regions, a strategy which was selected for its high perceived scientific and operational value. The first architecture discussed incorporates the lunar orbit rendezvous approach employed by the Apollo lunar exploration program. This concept has been adapted from Apollo to meet the particular demands of a long-stay polar exploration campaign while assuring the safe return of crew to Earth. Lunar orbit rendezvous is also used as the baseline against which the other alternate concepts are measured. The first such alternative, libration point rendezvous, utilizes the unique characteristics of the cislunar libration point instead of a low altitude lunar parking orbit as a rendezvous and staging node. Finally, a mission strategy which does not incorporate rendezvous after the crew ascends from the Moon is also studied. In this mission strategy, the crew returns directly to Earth from the lunar surface, and is thus referred to as direct return. Figures of merit in the areas of safety and mission success, mission effectiveness, extensibility, and affordability are used to evaluate and compare the lunar orbit rendezvous, libration point rendezvous, and direct return architectures, and this paper summarizes the results of those assessments.
Goddard earth models (5 and 6)
NASA Technical Reports Server (NTRS)
Lerch, F. J.; Wagner, C. A.; Richardson, J. A.; Brownd, J. E.
1974-01-01
A comprehensive earth model has been developed that consists of two complementary gravitational fields and center-of-mass locations for 134 tracking stations on the earth's surface. One gravitational field is derived solely from satellite tracking data. This data on 27 satellite orbits is the most extensive used for such a solution. A second solution uses this data with 13,400 simultaneous events from satellite camera observations and surface gravimetric anomalies. The satellite-only solution as a whole is accurate to about 4.5 milligals as judged by the surface gravity data. The majority of the station coordinates are accurate to better than 10 meters as judged by independent results from geodetic surveys and by Doppler tracking of both distant space probes and near earth orbits.
NASA Technical Reports Server (NTRS)
Christopher, Sundar A.; Wang, Min; Berendes, Todd A.; Welch, Ronald M.; Yang, Shi-Keng
1998-01-01
Using satellite imagery, more than five million square kilometers of the forest and cerrado regions over South America are extensively studied to monitor fires and smoke during the 1985 biomass burning season. The results are characterized for four major ecosystems, namely: (1) tropical rain forest, (2) tropical broadleaf seasonal, (3) savannah/grass and seasonal woods (SGW), and (4) mild/warm/hot grass/shrub (MGS). The spatial and temporal distribution of fires are examined from two different methods using the multispectral Advanced Very High Resolution Radiometer Local Area Coverage data. Using collocated measurements from the instantaneous scanner Earth Radiation Budget Experiment data, the direct regional radiative forcing of biomass burning aerosols is computed. The results show that more than 70% of the fires occur in the MGS and SGW ecosystems due to agricultural practices. The smoke generated from biomass burning has negative instantaneous net radiative forcing values for all four major ecosystems within South America. The smoke found directly over the fires has mean net radiative forcing values ranging from -25.6 to -33.9 W m(exp -2). These results confirm that the regional net radiative impact of biomass burning is one of cooling. The spectral and broadband properties for clear-sky and smoke regions are also presented that could be used as input and/or validation for other studies attempting to model the impact of aerosols on the earth-atmosphere system. These results have important applications for future instruments from the Earth Observing System (EOS) program. Specifically, the combination of the Visible Infrared Scanner and Clouds and the Earth's Radiant Energy System (CERES) instruments from the Tropical Rainfall Measuring Mission and the combination of Moderate Resolution Imaging Spectrometer and CERES instruments from the EOS morning crossing mission could provide reliable estimates of the direct radiative forcing of aerosols on a global scale, thereby reducing the uncertainties in current global aerosol radiative forcing values.
Developing an Earth system Inverse model for the Earth's energy and water budgets.
NASA Astrophysics Data System (ADS)
Haines, K.; Thomas, C.; Liu, C.; Allan, R. P.; Carneiro, D. M.
2017-12-01
The CONCEPT-Heat project aims at developing a consistent energy budget for the Earth system in order to better understand and quantify global change. We advocate a variational "Earth system inverse" solution as the best methodology to bring the necessary expertise from different disciplines together. L'Ecuyer et al (2015) and Rodell et al (2015) first used a variational approach to adjust multiple satellite data products for air-sea-land vertical fluxes of heat and freshwater, achieving closed budgets on a regional and global scale. However their treatment of horizontal energy and water redistribution and its uncertainties was limited. Following the recent work of Liu et al (2015, 2017) which used atmospheric reanalysis convergences to derive a new total surface heat flux product from top of atmosphere fluxes, we have revisited the variational budget approach introducing a more extensive analysis of the role of horizontal transports of heat and freshwater, using multiple atmospheric and ocean reanalysis products. We find considerable improvements in fluxes in regions such as the North Atlantic and Arctic, for example requiring higher atmospheric heat and water convergences over the Arctic than given by ERA-Interim, thereby allowing lower and more realistic oceanic transports. We explore using the variational uncertainty analysis to produce lower resolution corrections to higher resolution flux products and test these against in situ flux data. We also explore the covariance errors implied between component fluxes that are imposed by the regional budget constraints. Finally we propose this as a valuable methodology for developing consistent observational constraints on the energy and water budgets in climate models. We take a first look at the same regional budget quantities in CMIP5 models and consider the implications of the differences for the processes and biases active in the models. Many further avenues of investigation are possible focused on better valuing the uncertainties in observational flux products and setting requirement targets for future observation programs.
Hitting rock bottom: morphological responses of bedrock-confined streams to a catastrophic flood
NASA Astrophysics Data System (ADS)
Baggs Sargood, M.; Cohen, T. J.; Thompson, C. J.; Croke, J.
2015-06-01
The role of extreme events in shaping the Earth's surface is one that has held the interests of Earth scientists for centuries. A catastrophic flood in a tectonically quiescent setting in eastern Australia in 2011 provides valuable insight into how semi-alluvial channels respond to such events. Field survey data (3 reaches) and desktop analyses (10 reaches) with catchment areas ranging from 0.5 to 168 km2 show that the predicted discharge for the 2011 event ranged from 415 to 933 m3 s-1, with unit stream power estimates of up to 1077 W m-2. Estimated entrainment relationships predict the mobility of the entire grain-size population, and field data suggest the localised mobility of boulders up to 4.8 m in diameter. Analysis of repeat lidar data demonstrates that all reaches (field and desktop) were areas of net degradation via extensive scouring of coarse-grained alluvium with a strong positive relationship between catchment area and normalised erosion (R2 = 0.72-0.74). The extensive scouring in the 2011 flood decreased thalweg variance significantly removing previous step pools and other coarse-grained in-channel units, forming lengths of plane-bed (cobble) reach morphology. This was also accompanied by the exposure of planar bedrock surfaces, marginal bedrock straths and bedrock steps. Post-flood field data indicate a slight increase in thalweg variance as a result of the smaller 2013 flood rebuilding the alluvial overprint with pool-riffle formation. However, the current form and distribution of channel morphological units does not conform to previous classifications of bedrock or headwater river systems. This variation in post-flood form indicates that in semi-alluvial systems extreme events are significant for re-setting the morphology of in-channel units and for exposing the underlying lithology to ongoing erosion.
Earth system science: A program for global change
NASA Technical Reports Server (NTRS)
1989-01-01
The Earth System Sciences Committee (ESSC) was appointed to consider directions for the NASA Earth-sciences program, with the following charge: review the science of the Earth as a system of interacting components; recommend an implementation strategy for Earth studies; and define the role of NASA in such a program. The challenge to the Earth system science is to develop the capability to predict those changes that will occur in the next decade to century, both naturally and in response to human activity. Sustained, long-term measurements of global variables; fundamental descriptions of the Earth and its history; research foci and process studies; development of Earth system models; an information system for Earth system science; coordination of Federal agencies; and international cooperation are examined.
Grosch, Eugene G; Hazen, Robert M
2015-10-01
Earth is the most mineralogically diverse planet in our solar system, the direct consequence of a coevolving geosphere and biosphere. We consider the possibility that a microbial biosphere originated and thrived in the early Hadean-Archean Earth subseafloor environment, with fundamental consequences for the complex evolution and habitability of our planet. In this hypothesis paper, we explore possible venues for the origin of life and the direct consequences of microbially mediated, low-temperature hydrothermal alteration of the early oceanic lithosphere. We hypothesize that subsurface fluid-rock-microbe interactions resulted in more efficient hydration of the early oceanic crust, which in turn promoted bulk melting to produce the first evolved fragments of felsic crust. These evolved magmas most likely included sialic or tonalitic sheets, felsic volcaniclastics, and minor rhyolitic intrusions emplaced in an Iceland-type extensional setting as the earliest microcontinents. With the further development of proto-tectonic processes, these buoyant felsic crustal fragments formed the nucleus of intra-oceanic tonalite-trondhjemite-granitoid (TTG) island arcs. Thus microbes, by facilitating extensive hydrothermal alteration of the earliest oceanic crust through bioalteration, promoted mineral diversification and may have been early architects of surface environments and microcontinents on young Earth. We explore how the possible onset of subseafloor fluid-rock-microbe interactions on early Earth accelerated metavolcanic clay mineral formation, crustal melting, and subsequent metamorphic mineral evolution. We also consider environmental factors supporting this earliest step in geosphere-biosphere coevolution and the implications for habitability and mineral evolution on other rocky planets, such as Mars.
Modeling, simulation, and analysis of optical remote sensing systems
NASA Technical Reports Server (NTRS)
Kerekes, John Paul; Landgrebe, David A.
1989-01-01
Remote Sensing of the Earth's resources from space-based sensors has evolved in the past 20 years from a scientific experiment to a commonly used technological tool. The scientific applications and engineering aspects of remote sensing systems have been studied extensively. However, most of these studies have been aimed at understanding individual aspects of the remote sensing process while relatively few have studied their interrelations. A motivation for studying these interrelationships has arisen with the advent of highly sophisticated configurable sensors as part of the Earth Observing System (EOS) proposed by NASA for the 1990's. Two approaches to investigating remote sensing systems are developed. In one approach, detailed models of the scene, the sensor, and the processing aspects of the system are implemented in a discrete simulation. This approach is useful in creating simulated images with desired characteristics for use in sensor or processing algorithm development. A less complete, but computationally simpler method based on a parametric model of the system is also developed. In this analytical model the various informational classes are parameterized by their spectral mean vector and covariance matrix. These class statistics are modified by models for the atmosphere, the sensor, and processing algorithms and an estimate made of the resulting classification accuracy among the informational classes. Application of these models is made to the study of the proposed High Resolution Imaging Spectrometer (HRIS). The interrelationships among observational conditions, sensor effects, and processing choices are investigated with several interesting results.
Titan's atmosphere and climate
NASA Astrophysics Data System (ADS)
Hörst, S. M.
2017-03-01
Titan is the only moon with a substantial atmosphere, the only other thick N2 atmosphere besides Earth's, the site of extraordinarily complex atmospheric chemistry that far surpasses any other solar system atmosphere, and the only other solar system body with stable liquid currently on its surface. The connection between Titan's surface and atmosphere is also unique in our solar system; atmospheric chemistry produces materials that are deposited on the surface and subsequently altered by surface-atmosphere interactions such as aeolian and fluvial processes resulting in the formation of extensive dune fields and expansive lakes and seas. Titan's atmosphere is favorable for organic haze formation, which combined with the presence of some oxygen-bearing molecules indicates that Titan's atmosphere may produce molecules of prebiotic interest. The combination of organics and liquid, in the form of water in a subsurface ocean and methane/ethane in the surface lakes and seas, means that Titan may be the ideal place in the solar system to test ideas about habitability, prebiotic chemistry, and the ubiquity and diversity of life in the universe. The Cassini-Huygens mission to the Saturn system has provided a wealth of new information allowing for study of Titan as a complex system. Here I review our current understanding of Titan's atmosphere and climate forged from the powerful combination of Earth-based observations, remote sensing and in situ spacecraft measurements, laboratory experiments, and models. I conclude with some of our remaining unanswered questions as the incredible era of exploration with Cassini-Huygens comes to an end.
NASA Astrophysics Data System (ADS)
Paulsen, H.; Ilyina, T.; Six, K. D.
2016-02-01
Marine nitrogen fixers play a fundamental role in the oceanic nitrogen and carbon cycles by providing a major source of `new' nitrogen to the euphotic zone that supports biological carbon export and sequestration. Furthermore, nitrogen fixers may regionally have a direct impact on ocean physics and hence the climate system as they form extensive surface mats which can increase light absorption and surface albedo and reduce the momentum input by wind. Resulting alterations in temperature and stratification may feed back on nitrogen fixers' growth itself.We incorporate nitrogen fixers as a prognostic 3D tracer in the ocean biogeochemical component (HAMOCC) of the Max Planck Institute Earth system model and assess for the first time the impact of related bio-physical feedbacks on biogeochemistry and the climate system.The model successfully reproduces recent estimates of global nitrogen fixation rates, as well as the observed distribution of nitrogen fixers, covering large parts of the tropical and subtropical oceans. First results indicate that including bio-physical feedbacks has considerable effects on the upper ocean physics in this region. Light absorption by nitrogen fixers leads locally to surface heating, subsurface cooling, and mixed layer depth shoaling in the subtropical gyres. As a result, equatorial upwelling is increased, leading to surface cooling at the equator. This signal is damped by the effect of the reduced wind stress due to the presence of cyanobacteria mats, which causes a reduction in the wind-driven circulation, and hence a reduction in equatorial upwelling. The increase in surface albedo due to nitrogen fixers has only inconsiderable effects. The response of nitrogen fixers' growth to the alterations in temperature and stratification varies regionally. Simulations with the fully coupled Earth system model are in progress to assess the implications of the biologically induced changes in upper ocean physics for the global climate system.
NASA Technical Reports Server (NTRS)
Stefanov, William L.
2017-01-01
The NASA Earth observations dataset obtained by humans in orbit using handheld film and digital cameras is freely accessible to the global community through the online searchable database at https://eol.jsc.nasa.gov, and offers a useful compliment to traditional ground-commanded sensor data. The dataset includes imagery from the NASA Mercury (1961) through present-day International Space Station (ISS) programs, and currently totals over 2.6 million individual frames. Geographic coverage of the dataset includes land and oceans areas between approximately 52 degrees North and South latitudes, but is spatially and temporally discontinuous. The photographic dataset includes some significant impediments for immediate research, applied, and educational use: commercial RGB films and camera systems with overlapping bandpasses; use of different focal length lenses, unconstrained look angles, and variable spacecraft altitudes; and no native geolocation information. Such factors led to this dataset being underutilized by the community but recent advances in automated and semi-automated image geolocation, image feature classification, and web-based services are adding new value to the astronaut-acquired imagery. A coupled ground software and on-orbit hardware system for the ISS is in development for planned deployment in mid-2017; this system will capture camera pose information for each astronaut photograph to allow automated, full georegistration of the data. The ground system component of the system is currently in use to fully georeference imagery collected in response to International Disaster Charter activations, and the auto-registration procedures are being applied to the extensive historical database of imagery to add value for research and educational purposes. In parallel, machine learning techniques are being applied to automate feature identification and classification throughout the dataset, in order to build descriptive metadata that will improve search capabilities. It is expected that these value additions will increase interest and use of the dataset by the global community.
The airborne laser ranging system, its capabilities and applications
NASA Technical Reports Server (NTRS)
Kahn, W. D.; Degnan, J. J.; Englar, T. S., Jr.
1982-01-01
The airborne laser ranging system is a multibeam short pulse laser ranging system on board an aircraft. It simultaneously measures the distances between the aircraft and six laser retroreflectors (targets) deployed on the Earth's surface. The system can interrogate over 100 targets distributed over an area of 25,000 sq, kilometers in a matter of hours. Potentially, a total of 1.3 million individual range measurements can be made in a six hour flight. The precision of these range measurements is approximately + or - 1 cm. These measurements are used in procedure which is basically an extension of trilateration techniques to derive the intersite vector between the laser ground targets. By repeating the estimation of the intersite vector, strain and strain rate errors can be estimated. These quantities are essential for crustal dynamic studies which include determination and monitoring of regional strain in the vicinity of active fault zones, land subsidence, and edifice building preceding volcanic eruptions.
NASA Technical Reports Server (NTRS)
Webster, W. J., Jr.
1986-01-01
The shuttle-deployed and recovered Spartan shows promise as an inexpensive and simple support module for potential field measurements. The results of a preliminary engineering study on the applications of the Spartan carrier to magnetic measurements shows: (1) Extension of the mission duration to as long as 7 days is feasible but requires more reconfiguration of the internal systems; (2) On-board recording of Global Positioning System signals will provide position determination with an accuracy consistent with the most severe requirements; and (3) Making Spartan a magnetically clean spacecraft is straight forward but requires labor-intensive modifications to both the data and power systems. As a magnetic survey tool, Spartan would allow surveys at regularly spaced intervals and could make quick-reaction surveys at times of instability in the secular variation.
Diversity of Approaches to Structuring University-Based Earth System Science Education
NASA Astrophysics Data System (ADS)
Aron, J.; Ruzek, M.; Johnson, D. R.
2004-12-01
Over the past quarter century, the "Earth system science" paradigm has emerged among the interdisciplinary science community, emphasizing interactions among components hitherto considered within separate disciplines: atmosphere (air); hydrosphere (water); biosphere (life); lithosphere (land); anthroposphere (human dimension); and exosphere (solar system and beyond). How should the next generation of Earth system scientists learn to contribute to this interdisciplinary endeavor? There is no one simple answer. The Earth System Science Education program, funded by NASA, has addressed this question by supporting faculty at U.S. universities who develop new courses, curricula and degree programs in their institutional contexts. This report demonstrates the diversity of approaches to structuring university-based Earth system science education, focusing on the 18 current grantees of the Earth System Science Education Program for the 21st Century (ESSE21). One of the most fundamental characteristics is the departmental structure for teaching Earth system science. The "home" departments of the Earth system science faculty range from Earth sciences and physics to agronomy and social work. A brand-new institution created an interdisciplinary Institute for Earth Systems Science and Policy without traditional "parent" departments. Some institutions create new degree programs as majors or as minors while others work within existing degree programs to add or revise courses. A university may also offer multiple strands, such as a degree in the Science of the Earth System and a degree in the Human Dimensions of the Earth System. Defining a career path is extremely important to students considering Earth system science programs and a major institutional challenge for all programs in Earth system science education. How will graduate programs assess prospective students? How will universities and government agencies assess prospective faculty and scientists? How will government agencies allocate funds to interdisciplinary Earth system science and technology? Finally, how should the Earth system science education community evolve?
Evaluating Cloud Computing in the Proposed NASA DESDynI Ground Data System
NASA Technical Reports Server (NTRS)
Tran, John J.; Cinquini, Luca; Mattmann, Chris A.; Zimdars, Paul A.; Cuddy, David T.; Leung, Kon S.; Kwoun, Oh-Ig; Crichton, Dan; Freeborn, Dana
2011-01-01
The proposed NASA Deformation, Ecosystem Structure and Dynamics of Ice (DESDynI) mission would be a first-of-breed endeavor that would fundamentally change the paradigm by which Earth Science data systems at NASA are built. DESDynI is evaluating a distributed architecture where expert science nodes around the country all engage in some form of mission processing and data archiving. This is compared to the traditional NASA Earth Science missions where the science processing is typically centralized. What's more, DESDynI is poised to profoundly increase the amount of data collection and processing well into the 5 terabyte/day and tens of thousands of job range, both of which comprise a tremendous challenge to DESDynI's proposed distributed data system architecture. In this paper, we report on a set of architectural trade studies and benchmarks meant to inform the DESDynI mission and the broader community of the impacts of these unprecedented requirements. In particular, we evaluate the benefits of cloud computing and its integration with our existing NASA ground data system software called Apache Object Oriented Data Technology (OODT). The preliminary conclusions of our study suggest that the use of the cloud and OODT together synergistically form an effective, efficient and extensible combination that could meet the challenges of NASA science missions requiring DESDynI-like data collection and processing volumes at reduced costs.
NASA Astrophysics Data System (ADS)
Hopper, E.; Gaherty, J. B.; Shillington, D. J.
2016-12-01
Continental extension comes in many guises, often described in terms of two endmembers. Narrow rifting is typified by a rift valley narrower than lithospheric thickness (50-100 km), presumed to result in steep lateral changes in crustal and lithospheric topography; wide rifting by a broad zone (<1000 km) of normal faulting associated with much smaller topographic gradients. A type example for the former is the East African Rift Valley; for the latter, the Basin and Range in the western U.S.A. An important control on rift development is the state of the lithosphere: for example, its strength and thickness. We analyse common conversion point stacked Sp converted wave images of the lithosphere beneath rift systems in the contiguous U.S., both the wide Basin and Range, and narrow rift systems such as the Rio Grande Rift and Salton Trough. We use Sp waves recorded by EarthScope's Transportable Array and other available permanent and temporary broadband stations. Beneath the Basin and Range, we observe a very strong, shallow velocity decrease (the lithosphere-asthenosphere boundary, or LAB) that is relatively uniform over 100s of km. The strength of this feature indicates melt has ponded at this transition. We have not observed a clear relationship between lithospheric thickness beneath the Basin and Range, and total degree of extension, current extension rate, or age since surface volcanism. Beneath narrow rifts in the western U.S., however, more localised thinning of the lithosphere has been observed. We also compare these observations with seismic images of the Malawi Rift, at the southern end of the Western Branch of the East African Rift System, using broadband data acquired as part of the Study of Extension and MaGmatism in Malawi aNd Tanzania (SEGMeNT) experiment. The Malawi Rift is extending slowly in a magma-poor region of relatively strong lithosphere. We constrain the pattern of plate-scale extension by observations of crustal thinning, and image complex variations in deeper lithospheric structure.
NASA Astrophysics Data System (ADS)
Hopper, E.; Gaherty, J. B.; Shillington, D. J.
2017-12-01
Continental extension comes in many guises, often described in terms of two endmembers. Narrow rifting is typified by a rift valley narrower than lithospheric thickness (50-100 km), presumed to result in steep lateral changes in crustal and lithospheric topography; wide rifting by a broad zone (<1000 km) of normal faulting associated with much smaller topographic gradients. A type example for the former is the East African Rift Valley; for the latter, the Basin and Range in the western U.S.A. An important control on rift development is the state of the lithosphere: for example, its strength and thickness. We analyse common conversion point stacked Sp converted wave images of the lithosphere beneath rift systems in the contiguous U.S., both the wide Basin and Range, and narrow rift systems such as the Rio Grande Rift and Salton Trough. We use Sp waves recorded by EarthScope's Transportable Array and other available permanent and temporary broadband stations. Beneath the Basin and Range, we observe a very strong, shallow velocity decrease (the lithosphere-asthenosphere boundary, or LAB) that is relatively uniform over 100s of km. The strength of this feature indicates melt has ponded at this transition. We have not observed a clear relationship between lithospheric thickness beneath the Basin and Range, and total degree of extension, current extension rate, or age since surface volcanism. Beneath narrow rifts in the western U.S., however, more localised thinning of the lithosphere has been observed. We also compare these observations with seismic images of the Malawi Rift, at the southern end of the Western Branch of the East African Rift System, using broadband data acquired as part of the Study of Extension and MaGmatism in Malawi aNd Tanzania (SEGMeNT) experiment. The Malawi Rift is extending slowly in a magma-poor region of relatively strong lithosphere. We constrain the pattern of plate-scale extension by observations of crustal thinning, and image complex variations in deeper lithospheric structure.
NASA Astrophysics Data System (ADS)
Scheucher, Markus; Urbar, Jaroslav; Musset, Sophie; Andersson, Viktor; Gini, Francesco; Gorski, Jedrzej; Jüstel, Peter; Kiefer, René; Lee, Arrow; Meskers, Arjan; Miles, Oscar; Perakis, Nikolas; Rußwurm, Michael; Scully, Stephen; Seifert, Bernhard; Sorba, Arianna
2014-05-01
The effects of solar activity, especially Coronal Mass Ejections (CMEs), on Earth- and satellite-based systems are well-known and can cause major damage to space-dependent infrastructure. The main problem in current space weather forecasting is the inability to determine necessary forecast parameters of CMEs and Corotating Interaction Regions (CIRs) early enough to react. We present the design for a novel space mission consisting of two spacecraft that is aimed to perform stereoscopic measurements on Earth-directed CMEs and in-situ measurements of CIRs. The magnetic field orientation and structure of CMEs will be measured close to the Sun, using spectro-polarimetry. Geoeffectiveness will be derived by remote sensing the CMEs magnetic field at 0.64AU from the Sun, determining the full magnetic field vector of a CME. This will be achieved by the novel concept of measuring its polarising effects on spacecraft to spacecraft laser beams based upon heterodyne interferometry. Overall structure and trajectory of CMEs will also be monitored by heliospheric imagers and in-situ plasma instruments. To achieve the mission objectives, the orbit is heliocentric at 1AU with a separation angle from the Earth of ±50°. The operational mission lifetime is 6 years with a proposed 6 year extension. If implemented, Carrington will serve as a forecast system which will significantly improve the minimum forecast time for the fastest CMEs with 2000 km/s, from 13 minutes based on current L1 satellites, to around 3 hours.
Seismologic applications of GRACE time-variable gravity measurements
NASA Astrophysics Data System (ADS)
Li, Jin; Chen, Jianli; Zhang, Zizhan
2014-04-01
The Gravity Recovery and Climate Experiment (GRACE) has been measuring temporal and spatial variations of mass redistribution within the Earth system since 2002. As large earthquakes cause significant mass changes on and under the Earth's surface, GRACE provides a new means from space to observe mass redistribution due to earthquake deformations. GRACE serves as a good complement to other earthquake measurements because of its extensive spatial coverage and being free from terrestrial restriction. During its over 10 years mission, GRACE has successfully detected seismic gravitational changes of several giant earthquakes, which include the 2004 Sumatra-Andaman earthquake, 2010 Maule (Chile) earthquake, and 2011 Tohoku-Oki (Japan) earthquake. In this review, we describe by examples how to process GRACE time-variable gravity data to retrieve seismic signals, and summarize the results of recent studies that apply GRACE observations to detect co- and post-seismic signals and constrain fault slip models and viscous lithospheric structures. We also discuss major problems and give an outlook in this field of GRACE application.
Advances in Data Management in Remote Sensing and Climate Modeling
NASA Astrophysics Data System (ADS)
Brown, P. G.
2014-12-01
Recent commercial interest in "Big Data" information systems has yielded little more than a sense of deja vu among scientists whose work has always required getting their arms around extremely large databases, and writing programs to explore and analyze it. On the flip side, there are some commercial DBMS startups building "Big Data" platform using techniques taken from earth science, astronomy, high energy physics and high performance computing. In this talk, we will introduce one such platform; Paradigm4's SciDB, the first DBMS designed from the ground up to combine the kinds of quality-of-service guarantees made by SQL DBMS platforms—high level data model, query languages, extensibility, transactions—with the kinds of functionality familiar to scientific users—arrays as structural building blocks, integrated linear algebra, and client language interfaces that minimize the learning curve. We will review how SciDB is used to manage and analyze earth science data by several teams of scientific users.
Continuation of Global NO2 and SO2 Monitoring with Suomi NPP OMPS
NASA Astrophysics Data System (ADS)
Yang, K.; Zhang, H.; Wang, J.; Ge, C.; Wang, Y.
2017-12-01
We have produced high-quality NO2 and SO2 standard products (named NMNO2 and NMSO2 respectively) from the SNPP OMPS-NM daily global observations. These OMPS standard products have been archived and publicly released at NASA Goddard Earth Sciences Data and Information Services Center (https://daac.gsfc.nasa.gov/information/news/595e9675624016d1af392c73/omps-nm-no- 2-and-so-2-l-2-data-products-released). Analyses and comparisons have demonstrated that the qualities of these OMPS standard products match or surpass those of the corresponding OMI products, enabling the continuity and extension of these two key standard Earth System Data Records (ESDRs) that begun with NASA's EOS Aura mission using the SNPP observations. In this presentation, we summarize the new techniques and algorithm advances that improve the accuracy and consistency of these ESDRs from satellite observations, and highlight the regional changes in NO2 and SO2 detected from half a decade of SNPP OMPS observations.
Earth's oldest mantle fabrics indicate Eoarchaean subduction
Kaczmarek, Mary-Alix; Reddy, Steven M.; Nutman, Allen P.; Friend, Clark R. L.; Bennett, Vickie C.
2016-01-01
The extension of subduction processes into the Eoarchaean era (4.0–3.6 Ga) is controversial. The oldest reported terrestrial olivine, from two dunite lenses within the ∼3,720 Ma Isua supracrustal belt in Greenland, record a shape-preferred orientation of olivine crystals defining a weak foliation and a well-defined lattice-preferred orientation (LPO). [001] parallel to the maximum finite elongation direction and (010) perpendicular to the foliation plane define a B-type LPO. In the modern Earth such fabrics are associated with deformation of mantle rocks in the hanging wall of subduction systems; an interpretation supported by experiments. Here we show that the presence of B-type fabrics in the studied Isua dunites is consistent with a mantle origin and a supra-subduction mantle wedge setting, the latter supported by compositional data from nearby mafic rocks. Our results provide independent microstructural data consistent with the operation of Eoarchaean subduction and indicate that microstructural analyses of ancient ultramafic rocks provide a valuable record of Archaean geodynamics. PMID:26879892
Observation of Schumann Resonances in the Earth's Ionosphere
NASA Technical Reports Server (NTRS)
Simoes, Fernando; Pfaff, Robert; Freudenreich, Henry
2011-01-01
The surface of the Earth and the lower edge of the ionosphere define a cavity in which electromagnetic waves propagate. When the cavity is excited by broadband electromagnetic sources, e.g., lightning, a resonant state can develop provided the average equatorial circumference is approximately equal to an integral number of wavelengths of the electromagnetic waves. This phenomenon, known as Schumann resonance, corresponds to electromagnetic oscillations of the surface-ionosphere cavity, and has been used extensively to investigate atmospheric electricity. Using measurements from the Communications/Navigation Outage Forecasting System (C/NOFS) satellite, we report, for the first time, Schumann resonance signatures detected well beyond the upper boundary of the cavity. These results offer new means for investigating atmospheric electricity, tropospheric-ionospheric coupling mechanisms related to lightning activity, and wave propagation in the ionosphere. The detection of Schumann resonances in the ionosphere calls for revisions to the existing models of extremely low frequency wave propagation in the surface-ionosphere cavity. Additionally, these measurements suggest new remote sensing capabilities for investigating atmospheric electricity at other planets.
NASA Astrophysics Data System (ADS)
Zakharov, D. O.; Bindeman, I. N.
2015-12-01
The early Paleoproterozoic was an eventful period in the Earth's history. The first portions of free oxygen emerged in the atmosphere, Snowball Earth glaciations happened several times and the first supercontinent broke up due to extensive rifting. These events should have affected the stable isotopic composition of the hydrosphere. In this study, we use rocks that were altered in underwater hydrothermal systems to investigate the stable isotopic composition of the hydrosphere 2.39-2.45 billion years ago (hereinafter, Ga). Extremely low-δ18O (down to -27.5‰ SMOW) rocks from 2.39 Ga metamorphosed subglacial hydrothermal systems of the Belomorian belt, Baltic Shield formed at near-equatorial latitudes suggesting a Snowball (or Slushball) Earth glaciation. These results motivated us to look at temporally and geographically close hydrothermal systems from the unmetamorhposed 2.45 Ga Vetreny Belt rift. The length of the rift is 250 km and it is composed of high-Mg basalts, mafic-ultramafic intrusions and sedimentary successions. We examined several localities of high-Mg basalt flows that include astonishingly fresh pillow lavas, often with preserved volcanic glass, eruptive breccias, and hydrothermal alteration zones. Collected samples serve a great textural evidence of water-rock interaction that occurred in situ while basalts were cooling. The preliminary results from coexisting quartz and epidote (T, D18O=311°C), and from coexisting calcite and quartz (T, D18O=190°C) yield values of δ18O of involved water between -1.6 and -0.9 ‰. The values of δ13C in calcites vary between -4.0 and -2.3 ‰. It is likely that hydrothermal fluids operated in the Vetreny Belt rift were derived from seawater that is no different from modern oceanic water in terms of δ18O. Apparently, the rift was a Paleoproterozoic analog of the modern Red Sea, filled with oceanic water. The result is important because the Vetreny Belt rift predates the onset of Snowball Earth glaciation at 2.4 Ga. The results of our studies can be used as an initial point for meteoric water distillation models of the Paleoproterozoic hydrosphere that was involved in the global Snowball Earth glaciations.
Global regionalized seismicity in view of Non-Extensive Statistical Physics
NASA Astrophysics Data System (ADS)
Chochlaki, Kalliopi; Vallianatos, Filippos; Michas, Georgios
2018-03-01
In the present work we study the distribution of Earth's shallow seismicity on different seismic zones, as occurred from 1981 to 2011 and extracted from the Centroid Moment Tensor (CMT) catalog. Our analysis is based on the subdivision of the Earth's surface into seismic zones that are homogeneous with regards to seismic activity and orientation of the predominant stress field. For this, we use the Flinn-Engdahl regionalization (FE) (Flinn and Engdahl, 1965), which consists of fifty seismic zones as modified by Lombardi and Marzocchi (2007). The latter authors grouped the 50 FE zones into larger tectonically homogeneous ones, utilizing the cumulative moment tensor method, resulting into thirty-nine seismic zones. In each one of these seismic zones we study the distribution of seismicity in terms of the frequency-magnitude distribution and the inter-event time distribution between successive earthquakes, a task that is essential for hazard assessments and to better understand the global and regional geodynamics. In our analysis we use non-extensive statistical physics (NESP), which seems to be one of the most adequate and promising methodological tools for analyzing complex systems, such as the Earth's seismicity, introducing the q-exponential formulation as the expression of probability distribution function that maximizes the Sq entropy as defined by Tsallis, (1988). The qE parameter is significantly greater than one for all the seismic regions analyzed with value range from 1.294 to 1.504, indicating that magnitude correlations are particularly strong. Furthermore, the qT parameter shows some temporal correlations but variations with cut-off magnitude show greater temporal correlations when the smaller magnitude earthquakes are included. The qT for earthquakes with magnitude greater than 5 takes values from 1.043 to 1.353 and as we increase the cut-off magnitude to 5.5 and 6 the qT value ranges from 1.001 to 1.242 and from 1.001 to 1.181 respectively, presenting a significant decrease. Our findings support the ideas of universality within the Tsallis approach to describe Earth's seismicity and present strong evidence ontemporal clustering and long-range correlations of seismicity in each of the tectonic zonesanalyzed.
NASA Astrophysics Data System (ADS)
Passow, M. J.; Kastens, K. A.; Goodwillie, A. M.; Brenner, C.
2009-12-01
The Lamont-Doherty Earth Observatory of Columbia University (LDEO) continues its long history of contributions to public understanding of Science. Highlights of current efforts are described in paired posters. Part 2 focuses on web-based activities that foster access to LDEO cutting-edge research for worldwide audiences. “Geoscience Data Puzzles" are activities that purposefully present a high ratio of insight-to-effort for students. Each Puzzle uses selected authentic data to illuminate fundamental Earth processes typically taught in Earth Science curricula. Data may be in the form of a graph, table, map, image or combination of the above. Some Puzzles involve downloading a simple Excel file, but most can be worked from paper copies. Questions guide students through the process of data interpretion. Most Puzzles involve calculations, with emphasis on the too-seldom-taught skill of figuring out what math process is useful to answer an unfamiliar question or solve a problem. Every Puzzle offers "Aha" insights, when the connection between data and process or data and problem comes clear in a rewarding burst of illumination. Time needed to solve a Puzzle is between 15 minutes and an hour. “GeoMapApp” is a free, map-based data exploration and visualization application from the LDEO Marine Geoscience Data System group. GeoMapApp provides direct access to hundreds of data sets useful to geoscience educators, including continuously-updated Global Multi-Resolution Topography compilations that incorporates high-resolution bathymetry in the oceans and Space Shuttle elevations over land. A new User Guide, multi-media tutorials and webinar offer follow-along help and examples. “Virtual Ocean” integrates GeoMapApp functionality with NASA World Wind code to provide a powerful new 3-D platform for interdisciplinary geoscience research and education. Both GeoMapApp and Virtual Ocean foster scientific understanding and provide training in new data visualization technologies. LDEO scientists have contributed to the extensive collection of education resources developed by the Consortium for Ocean Leadership’s Deep Earth Academy). As part of the international research effort to interpret Earth's history by retrieving seafloor samples and monitoring subseafloor environments, LDEO's Borehole Research Group deploys downhole tools to acquire a wide variety of situ geophysical measurements. LDEO scientists contribute significantly to the web portal that facilitates communication between the drillship and the public. It features blogs, games, a graphic novel, teacher resources, and integration with Facebook and Twitter social networking sites Participants in LDEO's monthly "Earth2Class Workshops for Teachers" have created one of the most extensive collections of resources available in Earth Science education. These include curriculum units; teacher-developed lessons, activities, and power points; peer-provided tips for effective teaching; review guides to help prepare for standardized tests; selected web links, and more. Thousands of teachers and students around the world access these LDEO-developed resources every month during the school year.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Davis, Barry M.; McCaffrey, John G., E-mail: john.mccaffrey@nuim.ie
2016-01-28
Isolation of the heavier alkaline earth metals Ba and Sr in the solid rare gases (RGs) Ar, Kr, and Xe is analysed with absorption spectroscopy and interpreted partly with the assistance of ab initio calculations of the diatomic M ⋅ RG ground state interaction potentials. The y{sup 1}P←a{sup 1}S resonance transitions in the visible spectral region are used to compare the isolation conditions of these two metal atom systems and calcium. Complex absorption bands were recorded in all three metal atom systems even after extensive sample annealing. Coupled cluster calculations conducted on the ground states of the nine M ⋅more » RG diatomics (M = Ca, Sr, and Ba; RG = Ar, Kr, and Xe) at the coupled cluster single, double, and non-iterative triple level of theory revealed long bond lengths (>5 Å) and shallow bound regions (<130 cm{sup −1}). All of the M ⋅ RG diatomics have bond lengths considerably longer than those of the rare gas dimers, with the consequence that isolation of these metal atoms in a single substitutional site of the solid rare gas is unlikely, with the possible exception of Ca/Xe. The luminescence of metal dimer bands has been recorded for Ba and Sr revealing very different behaviours. Resonance fluorescence with a lifetime of 15 ns is observed for the lowest energy transition of Sr{sub 2} while this transition is quenched in Ba{sub 2}. This behaviour is consistent with the absence of vibrational structure on the dimer absorption band in Ba{sub 2} indicating lifetime broadening arising from efficient relaxation to low-lying molecular states. More extensive 2D excitation-emission data recorded for the complex site structures present on the absorption bands of the atomic Ba and Sr systems will be presented in future publications.« less
Gravity model improvement using the DORIS tracking system on the SPOT 2 satellite
NASA Technical Reports Server (NTRS)
Nerem, R. S.; Lerch, F. J.; Williamson, R. G.; Klosko, S. M.; Robbins, J. W.; Patel, G. B.
1994-01-01
A high-precision radiometric satellite tracking system, Doppler Orbitography and Radio-positioning Integrated by Satellite system (DORIS), has recently been developed by the French space agency, Centre National d'Etudes Spatiales (CNES). DORIS was designed to provide tracking support for missions such as the joint United States/French TOPEX/Poseidon. As part of the flight testing process, a DORIS package was flown on the French SPOT 2 satellite. A substantial quantity of geodetic quality tracking data was obtained on SPOT 2 from an extensive international DORIS tracking network. These data were analyzed to assess their accuracy and to evaluate the gravitational modeling enhancements provided by these data in combination with the Goddard Earth Model-T3 (GEM-T3) gravitational model. These observations have noise levels of 0.4 to 0.5 mm/s, with few residual systematic effects. Although the SPOT 2 satellite experiences high atmospheric drag forces, the precision and global coverage of the DORIS tracking data have enabled more extensive orbit parameterization to mitigate these effects. As a result, the SPOT 2 orbital errors have been reduced to an estimated radial accuracy in the 10-20 cm RMS range. The addition of these data, which encompass many regions heretofore lacking in precision satellite tracking, has significantly improved GEM-T3 and allowed greatly improved orbit accuracies for Sun-synchronous satellites like SPOT 2 (such as ERS 1 and EOS). Comparison of the ensuing gravity model with other contemporary fields (GRIM-4C2, TEG2B, and OSU91A) provides a means to assess the current state of knowledge of the Earth's gravity field. Thus, the DORIS experiment on SPOT 2 has provided a strong basis for evaluating this new orbit tracking technology and has demonstrated the important contribution of the DORIS network to the success of the TOPEX/Poseidon mission.
An Object-Based Approach to Evaluation of Climate Variability Projections and Predictions
NASA Astrophysics Data System (ADS)
Ammann, C. M.; Brown, B.; Kalb, C. P.; Bullock, R.
2017-12-01
Evaluations of the performance of earth system model predictions and projections are of critical importance to enhance usefulness of these products. Such evaluations need to address specific concerns depending on the system and decisions of interest; hence, evaluation tools must be tailored to inform about specific issues. Traditional approaches that summarize grid-based comparisons of analyses and models, or between current and future climate, often do not reveal important information about the models' performance (e.g., spatial or temporal displacements; the reason behind a poor score) and are unable to accommodate these specific information needs. For example, summary statistics such as the correlation coefficient or the mean-squared error provide minimal information to developers, users, and decision makers regarding what is "right" and "wrong" with a model. New spatial and temporal-spatial object-based tools from the field of weather forecast verification (where comparisons typically focus on much finer temporal and spatial scales) have been adapted to more completely answer some of the important earth system model evaluation questions. In particular, the Method for Object-based Diagnostic Evaluation (MODE) tool and its temporal (three-dimensional) extension (MODE-TD) have been adapted for these evaluations. More specifically, these tools can be used to address spatial and temporal displacements in projections of El Nino-related precipitation and/or temperature anomalies, ITCZ-associated precipitation areas, atmospheric rivers, seasonal sea-ice extent, and other features of interest. Examples of several applications of these tools in a climate context will be presented, using output of the CESM large ensemble. In general, these tools provide diagnostic information about model performance - accounting for spatial, temporal, and intensity differences - that cannot be achieved using traditional (scalar) model comparison approaches. Thus, they can provide more meaningful information that can be used in decision-making and planning. Future extensions and applications of these tools in a climate context will be considered.
NASA Astrophysics Data System (ADS)
McGovern, P. J., Jr.; Grosfils, E. B.; Le Corvec, N.; Ernst, R. E.; Galgana, G. A.
2017-12-01
Over 200 giant radial dike swarms have been identified on Venus using Magellan data, yielding insight into morphological characteristics long since erased by erosion and other processes on Earth. Since such radial dike systems are typically associated with magma reservoirs, large volcanoes and/or larger-scale plume activity—and because dike geometry reflects stress conditions at the time of intrusion—assessing giant radial dike formation in the context of swarm morphology can place important constraints upon this fundamental volcanotectonic process. Recent numerical models reveal that, contrary to what is reported in much of the published literature, it is not easy, mechanically, to produce either large or small radial dike systems. After extensive numerical examination of reservoir inflation, however, under conditions ranging from a simple halfspace to complex flexural loading, we have thus far identified four scenarios that produce radial dike systems. Two of these scenarios yield dike systems akin to those often associated with shield and stratocone volcanoes on Earth, while the other two, our focus here, are more consistent with the giant radial dike system geometries catalogued on Venus. In this presentation we will (a) review key morphological characteristics of the giant radial systems identified on Venus, (b) briefly illustrate why it is not easy, mechanically, to produce a radial dike system, (c) present the two volcanological circumstances we have identified that do allow a giant radial dike system to form, and (d) discuss current model limitations and potentially fruitful directions for future research.
Complex demodulation in VLBI estimation of high frequency Earth rotation components
NASA Astrophysics Data System (ADS)
Böhm, S.; Brzeziński, A.; Schuh, H.
2012-12-01
The spectrum of high frequency Earth rotation variations contains strong harmonic signal components mainly excited by ocean tides along with much weaker non-harmonic fluctuations driven by irregular processes like the diurnal thermal tides in the atmosphere and oceans. In order to properly investigate non-harmonic phenomena a representation in time domain is inevitable. We present a method, operating in time domain, which is easily applicable within Earth rotation estimation from Very Long Baseline Interferometry (VLBI). It enables the determination of diurnal and subdiurnal variations, and is still effective with merely diurnal parameter sampling. The features of complex demodulation are used in an extended parameterization of polar motion and universal time which was implemented into a dedicated version of the Vienna VLBI Software VieVS. The functionality of the approach was evaluated by comparing amplitudes and phases of harmonic variations at tidal periods (diurnal/semidiurnal), derived from demodulated Earth rotation parameters (ERP), estimated from hourly resolved VLBI ERP time series and taken from a recently published VLBI ERP model to the terms of the conventional model for ocean tidal effects in Earth rotation recommended by the International Earth Rotation and Reference System Service (IERS). The three sets of tidal terms derived from VLBI observations extensively agree among each other within the three-sigma level of the demodulation approach, which is below 6 μas for polar motion and universal time. They also coincide in terms of differences to the IERS model, where significant deviations primarily for several major tidal terms are apparent. An additional spectral analysis of the as well estimated demodulated ERP series of the ter- and quarterdiurnal frequency bands did not reveal any significant signal structure. The complex demodulation applied in VLBI parameter estimation could be demonstrated a suitable procedure for the reliable reproduction of high frequency Earth rotation components and thus represents a qualified tool for future studies of irregular geophysical signals in ERP measured by space geodetic techniques.
NASA Astrophysics Data System (ADS)
Koochak, Z.; Fraser-Smith, A. C.
2016-12-01
This paper is an extension of an earlier study of the centered and eccentric dipole models of the Earth's magnetic field [Fraser-Smith, 1987]. We have used the 1980-2015 International Geomagnetic Reference Field (IGRF) Gauss coefficients to recalculate the magnetic dipole moments and magnetic pole positions for both the centered and eccentric dipoles for an additional 35 years, thus bringing them up to date. These magnetic field models play an important role in ionosphere modification, since they influence the properties of the ionosphere. However it is not widely known that the nominal origin of the Earth's magnetic field is offset from the center of the Earth by nearly 10% of the Earth's radius, which must similarly lead to an offset of some of the larger-scale modifying effects such as those associated with the magnetosphere. We describe this offset magnetic field here to help identify its effects in ionospheric modification experiments.
NASA Technical Reports Server (NTRS)
1992-01-01
On December 16, 1992, 8 days after its encounter with Earth, the Galileo spacecraft looked back from a distance of about 6.2 million kilometers (3.9 million miles) to capture this remarkable view of the Moon in orbit about Earth. The composite photograph was constructed from images taken through visible (violet, red) and near-infrared (1.0-micron) filters. The Moon is in the foreground; its orbital path is from left to right. Brightly colored Earth contrasts strongly with the Moon, which reacts only about one-third as much sunlight as our world. To improve the visibility of both bodies, contrast and color have been computer enhanced. At the bottom of Earth's disk, Antarctica is visible through clouds. The Moon's far side can also be seen. The shadowy indentation in the Moon's dawn terminator--the boundary between its dark and lit sides--is the South Pole-Aitken Basin, one of the largest and oldest lunar impact features. This feature was studied extensively by Galileo during the first Earth flyby in December 1990.Impact compaction of a granular material
Fenton, Gregg; Asay, Blaine; Dalton, Devon
2015-05-19
The dynamic behavior of granular materials has importance to a variety of engineering applications. Structural seismic coupling, planetary science, and earth penetration mechanics, are just a few of the application areas. Although the mechanical behavior of granular materials of various types have been studied extensively for several decades, the dynamic behavior of such materials remains poorly understood. High-quality experimental data are needed to improve our general understanding of granular material compaction physics. This study will describe how an instrumented plunger impact system can be used to measure pressure-density relationships for model materials at high and controlled strain rates and subsequentlymore » used for computational modeling.« less
Ghost Imaging of Space Objects
NASA Technical Reports Server (NTRS)
Strekalov, Dmitry V.; Erkmen, Baris I.; Yu, Nan
2016-01-01
Development of innovative aerospace technologies is critical for our nation to meet its goals to explore and under-stand the Earth, our solar system, and the universe. The spectacular success of many recent NASA missions hinges on the extensive technological innovations that NASA has been supporting for the past decades. To sustain this successful tradition it is very important to identify and stimulate the scientific research that may turn into a viable technology in the decades yet to come. Investment in innovative low-TRL research stimulates the growth of the scientific knowledge and enhances the technical capabilities in a way that answers the new questions and responds to new requirements.
NASA Technical Reports Server (NTRS)
1991-01-01
CRRES is a program to study the space environment which surrounds Earth and the effects of space radiation on modern satellite electronic systems. The satellite will carry an array of active experiments including chemical releases and a complement of sophisticated scientific instruments to accomplish these objectives. Other chemical release active experiments will be performed with suborbital rocket probes. These chemical releases will paint the magnetic and electric fields in Earthspace with clouds of glowing ions. Earthspace will be a laboratory, and the releases will be studied with an extensive network of ground-, aircraft-, and satellite-based diagnostic instruments.
Standard-M mobile satellite terminal employing electronic beam squint tracking
NASA Technical Reports Server (NTRS)
Hawkins, G. J.; Beach, M. A.; Hilton, G. S.
1990-01-01
In recent years, extensive experience has been built up at the University of Bristol in the use of the Electronic Beam Squint (EBS) tracking technique, applied to large earth station facilities. The current interest in land mobile satellite terminals, using small tracking antennas, has prompted the investigation of the applicability of the EBS technique to this environment. The development of an L-band mechanically steered vehicle antenna is presented. A description of the antenna is followed by a detailed investigation of the tracking environment and its implications on the error detection capability of the system. Finally, the overall hardware configuration is described along with plans for future work.
Backscattering of decametric waves on magnetically oriented ionosphere inhomogeneities
NASA Astrophysics Data System (ADS)
Sivokon', V. P.
2017-05-01
The method of study of magnetically oriented ionosphere inhomogeneities based on the analysis of radar decametric emission backscattering on inhomogeneities is proposed. It is shown that certain conditions, including the orientation of the propagation route relative to the Earth's magnetic field lines and the polarization and frequency of the emitted wave, make possible resonant backscattering of radiolocation system emission on magnetically oriented ionosphere inhomogeneities. The paper presents the results of experimental observation of scattering in Kamchatka Peninsula. They demonstrated the opportunity to evaluate the extension of the scattering region, the vertical and horizontal components of the velocities of magnetically oriented inhomogeneities, and the frequency dependence of these parameters.
Climate stability of habitable Earth-like planets
NASA Astrophysics Data System (ADS)
Menou, Kristen
2015-11-01
The carbon-silicate cycle regulates the atmospheric CO2 content of terrestrial planets on geological timescales through a balance between the rates of CO2 volcanic outgassing and planetary intake from rock weathering. It is thought to act as an efficient climatic thermostat on Earth and, by extension, on other habitable planets. If, however, the weathering rate increases with the atmospheric CO2 content, as expected on planets lacking land vascular plants, the carbon-silicate cycle feedback can become severely limited. Here we show that Earth-like planets receiving less sunlight than current Earth may no longer possess a stable warm climate but instead repeatedly cycle between unstable glaciated and deglaciated climatic states. This has implications for the search for life on exoplanets in the habitable zone of nearby stars.
Strategy for earth explorers in global earth sciences
NASA Technical Reports Server (NTRS)
1988-01-01
The goal of the current NASA Earth System Science initiative is to obtain a comprehensive scientific understanding of the Earth as an integrated, dynamic system. The centerpiece of the Earth System Science initiative will be a set of instruments carried on polar orbiting platforms under the Earth Observing System program. An Earth Explorer program can open new vistas in the earth sciences, encourage innovation, and solve critical scientific problems. Specific missions must be rigorously shaped by the demands and opportunities of high quality science and must complement the Earth Observing System and the Mission to Planet Earth. The committee believes that the proposed Earth Explorer program provides a substantial opportunity for progress in the earth sciences, both through independent missions and through missions designed to complement the large scale platforms and international research programs that represent important national commitments. The strategy presented is intended to help ensure the success of the Earth Explorer program as a vital stimulant to the study of the planet.
Comparing TRAPPIST-1 to the Solar System
2018-02-05
This graph presents known properties of the seven TRAPPIST-1 exoplanets (labeled b through h), showing how they stack up to the inner rocky worlds in our own solar system. The horizontal axis shows the level of illumination that each planet receives from its host star. TRAPPIST-1 is a mere 9 percent the mass of our Sun, and its temperature is much cooler. But because the TRAPPIST-1 planets orbit so closely to their star, they receive comparable levels of light and heat to Earth and its neighboring planets. The vertical axis shows the densities of the planets. Density, calculated based on a planet's mass and volume, is the first important step in understanding a planet's composition. The plot shows that the TRAPPIST-1 planet densities range from being similar to Earth and Venus at the upper end, down to values comparable to Mars at the lower end. The relative sizes of the planets are indicated by the circles. The masses and densities of the TRAPPIST-1 planets were determined by careful measurements of slight variations in the timings of their orbits using extensive observations made by NASA's Spitzer and Kepler space telescopes, in combination with data from Hubble and a number of ground-based telescopes. These measurements are the most precise to date for any system of exoplanets. By comparing these measurements with theoretical models of how planets form and evolve, researchers have determined that they are all rocky in overall composition. Estimates suggest the lower-density planets could have large quantities of water -- as much as 5 percent by mass for TRAPPIST-1d. Earth, in comparison, has only about 0.02 percent of its mass in the form of water. https://photojournal.jpl.nasa.gov/catalog/PIA22095
NASA Astrophysics Data System (ADS)
Putman, W. M.; Suarez, M.
2009-12-01
The Goddard Earth Observing System Model (GEOS-5), an earth system model developed in the NASA Global Modeling and Assimilation Office (GMAO), has integrated the non-hydrostatic finite-volume dynamical core on the cubed-sphere grid. The extension to a non-hydrostatic dynamical framework and the quasi-uniform cubed-sphere geometry permits the efficient exploration of global weather and climate modeling at cloud permitting resolutions of 10- to 4-km on today's high performance computing platforms. We have explored a series of incremental increases in global resolution with GEOS-5 from it's standard 72-level 27-km resolution (~5.5 million cells covering the globe from the surface to 0.1 hPa) down to 3.5-km (~3.6 billion cells). We will present results from a series of forecast experiments exploring the impact of the non-hydrostatic dynamics at transition resolutions of 14- to 7-km, and the influence of increased horizontal/vertical resolution on convection and physical parameterizations within GEOS-5. Regional and mesoscale features of 5- to 10-day weather forecasts will be presented and compared with satellite observations. Our results will highlight the impact of resolution on the structure of cloud features including tropical convection and tropical cyclone predicability, cloud streets, von Karman vortices, and the marine stratocumulus cloud layer. We will also present experiment design and early results from climate impact experiments for global non-hydrostatic models using GEOS-5. Our climate experiments will focus on support for the Year of Tropical Convection (YOTC). We will also discuss a seasonal climate time-slice experiment design for downscaling coarse resolution century scale climate simulations to global non-hydrostatic resolutions of 14- to 7-km with GEOS-5.
The OGC Innovation Program Testbeds - Advancing Architectures for Earth and Systems
NASA Astrophysics Data System (ADS)
Bermudez, L. E.; Percivall, G.; Simonis, I.; Serich, S.
2017-12-01
The OGC Innovation Program provides a collaborative agile process for solving challenging science problems and advancing new technologies. Since 1999, 100 initiatives have taken place, from multi-million dollar testbeds to small interoperability experiments. During these initiatives, sponsors and technology implementers (including academia and private sector) come together to solve problems, produce prototypes, develop demonstrations, provide best practices, and advance the future of standards. This presentation will provide the latest system architectures that can be used for Earth and space systems as a result of the OGC Testbed 13, including the following components: Elastic cloud autoscaler for Earth Observations (EO) using a WPS in an ESGF hybrid climate data research platform. Accessibility of climate data for the scientist and non-scientist users via on demand models wrapped in WPS. Standards descriptions for containerize applications to discover processes on the cloud, including using linked data, a WPS extension for hybrid clouds and linking to hybrid big data stores. OpenID and OAuth to secure OGC Services with built-in Attribute Based Access Control (ABAC) infrastructures leveraging GeoDRM patterns. Publishing and access of vector tiles, including use of compression and attribute options reusing patterns from WMS, WMTS and WFS. Servers providing 3D Tiles and streaming of data, including Indexed 3d Scene Layer (I3S), CityGML and Common DataBase (CDB). Asynchronous Services with advanced pushed notifications strategies, with a filter language instead of simple topic subscriptions, that can be use across OGC services. Testbed 14 will continue advancing topics like Big Data, security, and streaming, as well as making easier to use OGC services (e.g. RESTful APIs). The Call for Participation will be issued in December and responses are due on mid January 2018.
The OGC Innovation Program Testbeds - Advancing Architectures for Earth and Systems
NASA Astrophysics Data System (ADS)
Bermudez, L. E.; Percivall, G.; Simonis, I.; Serich, S.
2016-12-01
The OGC Innovation Program provides a collaborative agile process for solving challenging science problems and advancing new technologies. Since 1999, 100 initiatives have taken place, from multi-million dollar testbeds to small interoperability experiments. During these initiatives, sponsors and technology implementers (including academia and private sector) come together to solve problems, produce prototypes, develop demonstrations, provide best practices, and advance the future of standards. This presentation will provide the latest system architectures that can be used for Earth and space systems as a result of the OGC Testbed 13, including the following components: Elastic cloud autoscaler for Earth Observations (EO) using a WPS in an ESGF hybrid climate data research platform. Accessibility of climate data for the scientist and non-scientist users via on demand models wrapped in WPS. Standards descriptions for containerize applications to discover processes on the cloud, including using linked data, a WPS extension for hybrid clouds and linking to hybrid big data stores. OpenID and OAuth to secure OGC Services with built-in Attribute Based Access Control (ABAC) infrastructures leveraging GeoDRM patterns. Publishing and access of vector tiles, including use of compression and attribute options reusing patterns from WMS, WMTS and WFS. Servers providing 3D Tiles and streaming of data, including Indexed 3d Scene Layer (I3S), CityGML and Common DataBase (CDB). Asynchronous Services with advanced pushed notifications strategies, with a filter language instead of simple topic subscriptions, that can be use across OGC services. Testbed 14 will continue advancing topics like Big Data, security, and streaming, as well as making easier to use OGC services (e.g. RESTful APIs). The Call for Participation will be issued in December and responses are due on mid January 2018.
Growing Food for Space and Earth: NASA's Contributions to Vertical Agriculture
NASA Technical Reports Server (NTRS)
Wheeler, Raymond M.
2015-01-01
Beginning in the 1980s with NASA's Controlled Ecological Life Support System (CELSS) Program and later the 1990s and early 2000s with the Advanced Life Support Project, NASA conducted extensive testing with crops in controlled environment conditions. One series of tests conducted at Kennedy Space Center used a large chamber with vertically stacked shelves to support hydroponic growing trays, with a bank of electric lamps above each shelf. This is essentially the same approach that has become popular for use in so-called vertical agriculture systems, which attempts to optimize plant production in a fixed volume. Some of the findings and commonalities of NASA's work during this period and how it overlaps with current interests in vertical agriculture will be presented in the talk.
The Ion Propulsion System for the Asteroid Redirect Robotic Mission
NASA Technical Reports Server (NTRS)
Herman, Daniel A.; Santiago, Walter; Kamhawi, Hani; Polk, James E.; Snyder, John Steven; Hofer, Richard; Sekerak, Michael
2016-01-01
The Asteroid Redirect Robotic Mission is a Solar Electric Propulsion Technology Demonstration Mission (ARRM) whose main objectives are to develop and demonstrate a high-power solar electric propulsion capability for the Agency and return an asteroidal mass for rendezvous and characterization in a companion human-crewed mission. This high-power solar electric propulsion capability, or an extensible derivative of it, has been identified as a critical part of NASA's future beyond-low-Earth-orbit, human-crewed exploration plans. This presentation presents the conceptual design of the ARRM ion propulsion system, the status of the NASA in-house thruster and power processing development activities, the status of the planned technology maturation for the mission through flight hardware delivery, and the status of the mission formulation and spacecraft acquisition.
Access High Quality Imagery from the NOAA View Portal
NASA Astrophysics Data System (ADS)
Pisut, D.; Powell, A. M.; Loomis, T.; Goel, V.; Mills, B.; Cowan, D.
2013-12-01
NOAA curates a vast treasure trove of environmental data, but one that is sometimes not easily accessed, especially for education, outreach, and media purposes. Traditional data portals in NOAA require extensive knowledge of the specific names of observation platforms, models, and analyses, along with nomenclature for variable outputs. A new website and web mapping service (WMS) from NOAA attempts to remedy such issues. The NOAA View data imagery portal provides a seamless entry point into data from across the agency: satellite, models, in-situ analysis, etc. The system provides the user with ability to browse, animate, and download high resolution (e.g., 4,000 x 2,000 pixel) imagery, Google Earth, and even proxy data files. The WMS architecture also allows the resources to be ingested into other software systems or applications.
GeoViQua: quality-aware geospatial data discovery and evaluation
NASA Astrophysics Data System (ADS)
Bigagli, L.; Papeschi, F.; Mazzetti, P.; Nativi, S.
2012-04-01
GeoViQua (QUAlity aware VIsualization for the Global Earth Observation System of Systems) is a recently started FP7 project aiming at complementing the Global Earth Observation System of Systems (GEOSS) with rigorous data quality specifications and quality-aware capabilities, in order to improve reliability in scientific studies and policy decision-making. GeoViQua main scientific and technical objective is to enhance the GEOSS Common Infrastructure (GCI) providing the user community with innovative quality-aware search and evaluation tools, which will be integrated in the GEO-Portal, as well as made available to other end-user interfaces. To this end, GeoViQua will promote the extension of the current standard metadata for geographic information with accurate and expressive quality indicators, also contributing to the definition of a quality label (GEOLabel). GeoViQua proposed solutions will be assessed in several pilot case studies covering the whole Earth Observation chain, from remote sensing acquisition to data processing, to applications in the main GEOSS Societal Benefit Areas. This work presents the preliminary results of GeoViQua Work Package 4 "Enhanced geo-search tools" (WP4), started in January 2012. Its major anticipated technical innovations are search and evaluation tools that communicate and exploit data quality information from the GCI. In particular, GeoViQua will investigate a graphical search interface featuring a coherent and meaningful aggregation of statistics and metadata summaries (e.g. in the form of tables, charts), thus enabling end users to leverage quality constraints for data discovery and evaluation. Preparatory work on WP4 requirements indicated that users need the "best" data for their purpose, implying a high degree of subjectivity in judgment. This suggests that the GeoViQua system should exploit a combination of provider-generated metadata (objective indicators such as summary statistics), system-generated metadata (contextual/tracking information such as provenance of data and metadata), and user-generated metadata (informal user comments, usage information, rating, etc.). Moreover, metadata should include sufficiently complete access information, to allow rich data visualization and propagation. The following main enabling components are currently identified within WP4: - Quality-aware access services, e.g. a quality-aware extension of the OGC Sensor Observation Service (SOS-Q) specification, to support quality constraints for sensor data publishing and access; - Quality-aware discovery services, namely a quality-aware extension of the OGC Catalog Service for the Web (CSW-Q), to cope with quality constrained search; - Quality-augmentation broker (GeoViQua Broker), to support the linking and combination of the existing GCI metadata with GeoViQua- and user-generated metadata required to support the users in selecting the "best" data for their intended use. We are currently developing prototypes of the above quality-enabled geo-search components, that will be assessed in a sensor-based pilot case study in the next months. In particular, the GeoViQua Broker will be integrated with the EuroGEOSS Broker, to implement CSW-Q and federate (either via distribution or harvesting schemes) quality-aware data sources, GeoViQua will constitute a valuable test-bed for advancing the current best practices and standards in geospatial quality representation and exploitation. The research leading to these results has received funding from the European Community's Seventh Framework Programme (FP7/2007-2013) under Grant Agreement n° 265178.
Tectonics and volcanism on Mars: a compared remote sensing analysis with earthly geostructures
NASA Astrophysics Data System (ADS)
Baggio, Paolo; Ancona, M. A.; Callegari, I.; Pinori, S.; Vercellone, S.
1999-12-01
The recent knowledge on Mars' lithosphere evolution does not find yet sufficient analogies with the Earth's tectonic models. The Viking image analysis seems to be even now frequently, rather fragmentary, and do not permits to express any coherent relationships among the different detected phenomena. Therefore, today it is impossible to support any reliable kinematic hypothesis. The Remote-Sensing interpretation is addressed to a Viking image mosaic of the known Tharsis Montes region and particularly focused on the Arsia Mons volcano. Several previously unknown lineaments, not directly linked to volcano-tectonics, were detected. Their mutual relationships recall transcurrent kinematics that could be related to similar geostructural models known in the Earth plate tectonic dynamics. Several concordant relationships between the Arsia Mons volcano and the brittle extensive tectonic features of earthly Etnean district (Sicily, South Italy), interpreted on Landsat TM images, were pointed out. These analogies coupled with the recently confirmed strato- volcano topology of Tharsis Montes (Head and Wilson), the layout distribution of the effusive centers (Arsia, Pavonis and Ascraeus Montes), the new tectonic lineaments and the morphological features, suggest the hypothesis of a plate tectonic volcanic region. The frame could be an example in agreement with the most recent interpretation of Mars (Sleep). A buried circular body, previously incorrectly interpreted as a great landslide event from the western slope of Arsia Mons volcano, seems really to be a more ancient volcanic structure (Arsia Mons Senilis), which location is in evident relation with the interpreted new transcurrent tectonic system.
NASA Astrophysics Data System (ADS)
Helmuth, Douglas B.; Bell, Raymond M.; Grant, David A.; Lentz, Christopher A.
2012-09-01
Architecting the operational Next Generation of earth monitoring satellites based on matured climate modeling, reuse of existing sensor & satellite capabilities, attention to affordability and evolutionary improvements integrated with constellation efficiencies - becomes our collective goal for an open architectural design forum. Understanding the earth's climate and collecting requisite signatures over the next 30 years is a shared mandate by many of the world's governments. But there remains a daunting challenge to bridge scientific missions to 'operational' systems that truly support the demands of decision makers, scientific investigators and global users' requirements for trusted data. In this paper we will suggest an architectural structure that takes advantage of current earth modeling examples including cross-model verification and a first order set of critical climate parameters and metrics; that in turn, are matched up with existing space borne collection capabilities and sensors. The tools used and the frameworks offered are designed to allow collaborative overlays by other stakeholders nominating different critical parameters and their own treaded connections to existing international collection experience. These aggregate design suggestions will be held up to group review and prioritized as potential constellation solutions including incremental and spiral developments - including cost benefits and organizational opportunities. This Part IV effort is focused on being an inclusive 'Next Gen Constellation' design discussion and is the natural extension to earlier papers.
Natural Variation of the Circadian Clock in Neurospora.
Koritala, Bala S C; Lee, Kwangwon
2017-01-01
Most living organisms on earth experience daily and expected changes from the rotation of the earth. For an organism, the ability to predict and prepare for incoming stresses or resources is a very important skill for survival. This cellular process of measuring daily time of the day is collectively called the circadian clock. Because of its fundamental role in survival in nature, there is a great interest in studying the natural variation of the circadian clock. However, characterizing the genetic and molecular mechanisms underlying natural variation of circadian clocks remains a challenging task. In this chapter, we will summarize the progress in studying natural variation of the circadian clock in the successful eukaryotic model Neurospora, which led to discovering many design principles of the molecular mechanisms of the eukaryotic circadian clock. Despite the success of the system in revealing the molecular mechanisms of the circadian clock, Neurospora has not been utilized to extensively study natural variation. We will review the challenges that hindered the natural variation studies in Neurospora, and how they were overcome. We will also review the advantages of Neurospora for natural variation studies. Since Neurospora is the model fungal species for circadian study, it represents over 5 million species of fungi on earth. These fungi play important roles in ecosystems on earth, and as such Neurospora could serve as an important model for understanding the ecological role of natural variation in fungal circadian clocks. © 2017 Elsevier Inc. All rights reserved.
Space Fission Propulsion System Development Status
NASA Technical Reports Server (NTRS)
Houts, Mike; VanDyke, Melissa; Godfroy, Tom; Pedersen, Kevin; Martin, James; Dickens, Ricky; Williams, Eric; Harper, Roger; Salvail, Pat; Hrbud, Ivana;
2001-01-01
The world's first man-made self-sustaining fission reaction was achieved in 1942. Since then fission has been used to propel submarines, generate tremendous amounts of electricity, produce medical isotopes, and provide numerous other benefits to society. Fission systems operate independently of solar proximity or orientation, and are thus well suited for deep spare or planetary surface missions. In addition, the fuel for fission systems (enriched uranium) is virtually non-radioactive. The primary safety issue with fission systems is avoiding inadvertent system start - addressing this issue through proper system design is straightforward. Despite the relative simplicity and tremendous potential of space fission systems, the development and utilization of these systems has proven elusive. The first use of fission technology in space occurred 3 April 1965 with the US launch of the SNAP-10A reactor. There have been no additional US uses of space fission system. While space fission system were used extensively by the former Soviet Union, their application was limited to earth-orbital missions. Early space fission systems must be safely and affordably utilized if Ae are to reap the benefits of advanced space fission systems.
Passive solar/earth sheltered office/dormitory cooling season thermal performance
DOE Office of Scientific and Technical Information (OSTI.GOV)
Christian, J.
1984-01-01
Continuous detailed hourly thermal performance measurements have been taken since February 1982 in and around an occupied, underground, 4000 ft/sup 2/ office/dormitory building at the Oak Ridge National Laboratory in Oak Ridge, Tennessee. This building has a number of energy saving features which have been analyzed relative to their performance in a southeastern US climate and with respect to overall commercial building performance. This analysis documents cooling season performance, as well as effects of earth contact, interior thermal mass, an economizer cycle and interface of an efficient building envelope with a central three-ton heat pump. The Joint Institute Dormitory obtainsmore » a cooling energy savings of about 30% compared with an energy-efficient, above-grade structure and has the potential to save as much as 50%. The proper installation of the overhand, interior thermal mass, massive supply duct system, and earth contact team up to prevent summertime overheating. From May through September, this building cost a total of $300 (at 5.7 cents/kWh) to cool and ventilate 24 hours per day. Besides thermal performance of the building envelope, extensive comfort data was taken illustrating that at least 90% of the occupants are comfortable all of the time according to the PMV measurements.« less
The International Heliophysical Year Education and Outreach Program
NASA Astrophysics Data System (ADS)
Rabello-Soares, M.; Morrow, C.; Thompson, B.
2006-12-01
The International Heliophysical Year (IHY) will celebrate the 50th anniversary of the International Geophysical Year (IGY) and will continue its tradition of international research collaboration. The term "heliophysical" is an extension of the term "geophysical", where the Earth, Sun & Solar System are studied not as separate domains but through the universal processes governing the heliosphere. IHY represents a logical next-step, extending the studies into the heliosphere and thus including the drivers of geophysical change. The main goal of IHY Education and Outreach Program is to create more global access to exemplary resources in space and earth science education and public outreach. By taking advantage of the IHY organization with representatives in every nation and in the partnership with the United Nations Basic Space Science Initiative (UNBSSI), we aim to promote new international partnerships. Our goal is to assist in increasing the visibility and accessibility of exemplary programs and in the identification of formal or informal educational products that would be beneficial to improve the space and earth science knowledge in a given country; leaving a legacy of enhanced global access to resources and of world-wide connectivity between those engaged in education and public outreach efforts that are related to IHY science. Here we describe the IHY Education and Outreach Program, how to participate and the benefits in doing so. ~
Comparison of Two IRI plasmasphere Extensions with GPS-TEC Observations
NASA Technical Reports Server (NTRS)
Gulyaeva, T. L.; Gallagher, Dennis L.
2006-01-01
Comparisons of two model results with Global Positioning System GPS-TEC measurements have been carried out for different latitudinal, solar activity, magnetic activity, diurnal and seasonal conditions. The models evaluated are the Global Core Plasma Model (GCPM-2000) and the IRI extension with Russian plasmasphere model (IRI*).Data of 23 observatories providing GPS-TEC and ionosonde data have been used. It is shown that IRI* plasmasphere electron density is greater than GCPM results by an order of magnitude at 6370 km altitude (one Earth's radius) with this excess growing to 2-3 orders of magnitude towards the GPS satellite altitude of 20000 km. Another source of model and GPS-TEC differences is a way of selection of the F2 layer peak parameters driving the models either with ITU-R (former CCIR) maps or ionosonde observations. Plasmasphere amendment to IRI improves accuracy of TEC model predictions because the plasmasphere contribution to the total TEC varies from 10% by daytime under quiet magnetic conditions to more than 50% by night under stormy conditions.
NASA Technical Reports Server (NTRS)
Gatos, H. C.; Witt, A. F.; Lichtensteiger, M.; Herman, C. J.
1982-01-01
The crystal growth and segregation characteristics of a melt in a directional solidification configuration under near zero g conditions were investigated. The germanium (doped with gallium) system was selected because it was extensively studied on Earth and because it lends itself to a very detailed macroscopic and microscopic characterization. An extensive study was performed of the germanium crystals grown during the Apollo-Soyuz Test Project mission. It was found that single crystal growth was achieved and that the interface demarcation functioned successfully. On the basis of the results obtained to date, there is no indication that convection driven by thermal or surface tension gradients was present in the melt. The gallium segregation, in the absence of gravity, was found to be fundamentally different in its initial and its subsequent stages from that of the ground based tests. None of the existing theoretical models for growth and segregation can account for the observed segregation behavior in the absence of gravity.
Seismicity of the Earth 1900-2013 East African Rift
Hayes, Gavin P.; Jones, Eric S.; Stadler, Timothy J.; Barnhart, William D.; McNamara, Daniel E.; Benz, Harley M.; Furlong, Kevin P.; Villaseñor, Antonio; Hayes, Gavin P.; Jones, Eric S.; Stadler, Timothy J.; Barnhart, William D.; McNamara, Daniel E.; Benz, Harley M.; Furlong, Kevin P.; Villaseñor, Antonio
2014-01-01
Rifting in East Africa is not all coeval; volcanism and faulting have been an ongoing phenomenon on the continent since the Eocene (~45 Ma). The rifting began in northern East Africa, and led to the separation of the Nubia (Africa) and Arabia plates in the Red Sea and Gulf of Aden, and in the Lake Turkana area at the Kenya-Ethiopia border. A Paleogene mantle superplume beneath East Africa caused extension within the Nubia plate, as well as a first order topographic high known as the African superswell which now includes most of the eastern and southern sectors of the Nubia plate. Widespread volcanism erupted onto much of the rising plateau in Ethiopia during the Eocene-Oligocene (45–29 Ma), with chains of volcanoes forming along the rift separating Africa and Arabia. Since the initiation of rifting in northeastern Africa, the system has propagated over 3,000 km to the south and southwest, and it experiences seismicity as a direct result of the extension and active magmatism.
NASA Astrophysics Data System (ADS)
El-Wakil, S. A.; Abulwafa, Essam M.; Elhanbaly, Atalla A.
2017-07-01
Based on Sagdeev pseudo-potential and phase-portrait, the dynamics of four-component dust plasma with non-extensively distributed electrons and ions are investigated. Three distinct types of nonlinear waves, namely, soliton, double layer, and super-soliton, have been found. The basic features of such waves are high sensitivity to Mach number, non-extensive parameter, and dust temperature ratio. It is found that the multi-component plasma is a necessary condition for super-soliton's existence, having a wider amplitude and a larger width than the regular soliton. Super-solitons may also exist when the Sagdeev pseudo-potential curves admit at least four extrema and two roots. In our multi-component plasma system, the super-solitons can be found by increasing the Mach number and the non-extensive parameter beyond those of double-layers. On the contrary, the super-soliton can be produced by decreasing the dust temperature ratio. The conditions of the onset of such nonlinear waves and its merging to regular solitons have been studied. This work shows that the obtained nonlinear waves are found to exist only in the super-sonic Mach number regime. The obtained results may be of wide relevance in the field of space plasma and may also be helpful to better understand the nonlinear fluctuations in the Auroral-zone of the Earth's magnetosphere.
The Global Modeling and Assimilation Office (GMAO) 4d-Var and its Adjoint-based Tools
NASA Technical Reports Server (NTRS)
Todling, Ricardo; Tremolet, Yannick
2008-01-01
The fifth generation of the Goddard Earth Observing System (GEOS-5) Data Assimilation System (DAS) is a 3d-var system that uses the Grid-point Statistical Interpolation (GSI) system developed in collaboration with NCEP, and a general circulation model developed at Goddard, that includes the finite-volume hydrodynamics of GEOS-4 wrapped in the Earth System Modeling Framework and physical packages tuned to provide a reliable hydrological cycle for the integration of the Modern Era Retrospective-analysis for Research and Applications (MERRA). This MERRA system is essentially complete and the next generation GEOS is under intense development. A prototype next generation system is now complete and has been producing preliminary results. This prototype system replaces the GSI-based Incremental Analysis Update procedure with a GSI-based 4d-var which uses the adjoint of the finite-volume hydrodynamics of GEOS-4 together with a vertical diffusing scheme for simplified physics. As part of this development we have kept the GEOS-5 IAU procedure as an option and have added the capability to experiment with a First Guess at the Appropriate Time (FGAT) procedure, thus allowing for at least three modes of running the data assimilation experiments. The prototype system is a large extension of GEOS-5 as it also includes various adjoint-based tools, namely, a forecast sensitivity tool, a singular vector tool, and an observation impact tool, that combines the model sensitivity tool with a GSI-based adjoint tool. These features bring the global data assimilation effort at Goddard up to date with technologies used in data assimilation systems at major meteorological centers elsewhere. Various aspects of the next generation GEOS will be discussed during the presentation at the Workshop, and preliminary results will illustrate the discussion.
NASA Astrophysics Data System (ADS)
Hsu, Juno; Prather, Michael J.; Cameron-Smith, Philip; Veidenbaum, Alex; Nicolau, Alex
2017-07-01
Solar-J is a comprehensive radiative transfer model for the solar spectrum that addresses the needs of both solar heating and photochemistry in Earth system models. Solar-J is a spectral extension of Cloud-J, a standard in many chemical models that calculates photolysis rates in the 0.18-0.8 µm region. The Cloud-J core consists of an eight-stream scattering, plane-parallel radiative transfer solver with corrections for sphericity. Cloud-J uses cloud quadrature to accurately average over correlated cloud layers. It uses the scattering phase function of aerosols and clouds expanded to eighth order and thus avoids isotropic-equivalent approximations prevalent in most solar heating codes. The spectral extension from 0.8 to 12 µm enables calculation of both scattered and absorbed sunlight and thus aerosol direct radiative effects and heating rates throughout the Earth's atmosphere.The Solar-J extension adopts the correlated-k gas absorption bins, primarily water vapor, from the shortwave Rapid Radiative Transfer Model for general circulation model (GCM) applications (RRTMG-SW). Solar-J successfully matches RRTMG-SW's tropospheric heating profile in a clear-sky, aerosol-free, tropical atmosphere. We compare both codes in cloudy atmospheres with a liquid-water stratus cloud and an ice-crystal cirrus cloud. For the stratus cloud, both models use the same physical properties, and we find a systematic low bias of about 3 % in planetary albedo across all solar zenith angles caused by RRTMG-SW's two-stream scattering. Discrepancies with the cirrus cloud using any of RRTMG-SW's three different parameterizations are as large as about 20-40 % depending on the solar zenith angles and occur throughout the atmosphere.Effectively, Solar-J has combined the best components of RRTMG-SW and Cloud-J to build a high-fidelity module for the scattering and absorption of sunlight in the Earth's atmosphere, for which the three major components - wavelength integration, scattering, and averaging over cloud fields - all have comparably small errors. More accurate solutions with Solar-J come with increased computational costs, about 5 times that of RRTMG-SW for a single atmosphere. There are options for reduced costs or computational acceleration that would bring costs down while maintaining improved fidelity and balanced errors.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Hsu, Juno; Prather, Michael J.; Cameron-Smith, Philip
Solar-J is a comprehensive radiative transfer model for the solar spectrum that addresses the needs of both solar heating and photochemistry in Earth system models. Solar-J is a spectral extension of Cloud-J, a standard in many chemical models that calculates photolysis rates in the 0.18–0.8 µm region. The Cloud-J core consists of an eight-stream scattering, plane-parallel radiative transfer solver with corrections for sphericity. Cloud-J uses cloud quadrature to accurately average over correlated cloud layers. It uses the scattering phase function of aerosols and clouds expanded to eighth order and thus avoids isotropic-equivalent approximations prevalent in most solar heating codes. Themore » spectral extension from 0.8 to 12 µm enables calculation of both scattered and absorbed sunlight and thus aerosol direct radiative effects and heating rates throughout the Earth's atmosphere. Furthermore, the Solar-J extension adopts the correlated-k gas absorption bins, primarily water vapor, from the shortwave Rapid Radiative Transfer Model for general circulation model (GCM) applications (RRTMG-SW). Solar-J successfully matches RRTMG-SW's tropospheric heating profile in a clear-sky, aerosol-free, tropical atmosphere. Here, we compare both codes in cloudy atmospheres with a liquid-water stratus cloud and an ice-crystal cirrus cloud. For the stratus cloud, both models use the same physical properties, and we find a systematic low bias of about 3 % in planetary albedo across all solar zenith angles caused by RRTMG-SW's two-stream scattering. Discrepancies with the cirrus cloud using any of RRTMG-SW's three different parameterizations are as large as about 20–40 % depending on the solar zenith angles and occur throughout the atmosphere. Effectively, Solar-J has combined the best components of RRTMG-SW and Cloud-J to build a high-fidelity module for the scattering and absorption of sunlight in the Earth's atmosphere, for which the three major components – wavelength integration, scattering, and averaging over cloud fields – all have comparably small errors. More accurate solutions with Solar-J come with increased computational costs, about 5 times that of RRTMG-SW for a single atmosphere. There are options for reduced costs or computational acceleration that would bring costs down while maintaining improved fidelity and balanced errors.« less
Hsu, Juno; Prather, Michael J.; Cameron-Smith, Philip; ...
2017-01-01
Solar-J is a comprehensive radiative transfer model for the solar spectrum that addresses the needs of both solar heating and photochemistry in Earth system models. Solar-J is a spectral extension of Cloud-J, a standard in many chemical models that calculates photolysis rates in the 0.18–0.8 µm region. The Cloud-J core consists of an eight-stream scattering, plane-parallel radiative transfer solver with corrections for sphericity. Cloud-J uses cloud quadrature to accurately average over correlated cloud layers. It uses the scattering phase function of aerosols and clouds expanded to eighth order and thus avoids isotropic-equivalent approximations prevalent in most solar heating codes. Themore » spectral extension from 0.8 to 12 µm enables calculation of both scattered and absorbed sunlight and thus aerosol direct radiative effects and heating rates throughout the Earth's atmosphere. Furthermore, the Solar-J extension adopts the correlated-k gas absorption bins, primarily water vapor, from the shortwave Rapid Radiative Transfer Model for general circulation model (GCM) applications (RRTMG-SW). Solar-J successfully matches RRTMG-SW's tropospheric heating profile in a clear-sky, aerosol-free, tropical atmosphere. Here, we compare both codes in cloudy atmospheres with a liquid-water stratus cloud and an ice-crystal cirrus cloud. For the stratus cloud, both models use the same physical properties, and we find a systematic low bias of about 3 % in planetary albedo across all solar zenith angles caused by RRTMG-SW's two-stream scattering. Discrepancies with the cirrus cloud using any of RRTMG-SW's three different parameterizations are as large as about 20–40 % depending on the solar zenith angles and occur throughout the atmosphere. Effectively, Solar-J has combined the best components of RRTMG-SW and Cloud-J to build a high-fidelity module for the scattering and absorption of sunlight in the Earth's atmosphere, for which the three major components – wavelength integration, scattering, and averaging over cloud fields – all have comparably small errors. More accurate solutions with Solar-J come with increased computational costs, about 5 times that of RRTMG-SW for a single atmosphere. There are options for reduced costs or computational acceleration that would bring costs down while maintaining improved fidelity and balanced errors.« less
An assessment of waste processing/resource recovery technologies for lunar/Mars life applications
NASA Technical Reports Server (NTRS)
Verostko, Charles E.; Packham, Nigel J. C.; Henninger, Donald H.
1992-01-01
NASA's future manned missions to explore the solar system are by nature of long duration, mandating extensive regeneration of life support consumables from wastes generated in space-based habitats. Long-duration exploration missions would otherwise be prohibitive due to the number and frequency of energy-intensive resupply missions from Earth. Resource recovery is therefore a critical component of the controlled ecological life support system (CELSS). In order to assess resource recovery technologies for CELSS applications, the Crew and Thermal Systems Division at NASA-Johnson Space Center convened a three-day workshop to assess potential resource recovery technologies for application in a space-based CELSS. This paper describes the methodology of assessing and ranking of these technologies. Recommendations and issues are identified. Evaluations focused on the processes for handling and treatment of inedible plant biomass, human waste, and human generated trash. Technologies were assessed on the basis of safety, reliability, technology readiness, and performance characteristics.
Evolving EO-1 Sensor Web Testbed Capabilities in Pursuit of GEOSS
NASA Technical Reports Server (NTRS)
Mandi, Dan; Ly, Vuong; Frye, Stuart; Younis, Mohamed
2006-01-01
A viewgraph presentation to evolve sensor web capabilities in pursuit of capabilities to support Global Earth Observing System of Systems (GEOSS) is shown. The topics include: 1) Vision to Enable Sensor Webs with "Hot Spots"; 2) Vision Extended for Communication/Control Architecture for Missions to Mars; 3) Key Capabilities Implemented to Enable EO-1 Sensor Webs; 4) One of Three Experiments Conducted by UMBC Undergraduate Class 12-14-05 (1 - 3); 5) Closer Look at our Mini-Rovers and Simulated Mars Landscae at GSFC; 6) Beginning to Implement Experiments with Standards-Vision for Integrated Sensor Web Environment; 7) Goddard Mission Services Evolution Center (GMSEC); 8) GMSEC Component Catalog; 9) Core Flight System (CFS) and Extension for GMSEC for Flight SW; 10) Sensor Modeling Language; 11) Seamless Ground to Space Integrated Message Bus Demonstration (completed December 2005); 12) Other Experiments in Queue; 13) Acknowledgements; and 14) References.
Operation and performance of the mars exploration rover imaging system on the martian surface
Maki, J.N.; Litwin, T.; Schwochert, M.; Herkenhoff, K.
2005-01-01
The Imaging System on the Mars Exploration Rovers has successfully operated on the surface of Mars for over one Earth year. The acquisition of hundreds of panoramas and tens of thousands of stereo pairs has enabled the rovers to explore Mars at a level of detail unprecedented in the history of space exploration. In addition to providing scientific value, the images also play a key role in the daily tactical operation of the rovers. The mobile nature of the MER surface mission requires extensive use of the imaging system for traverse planning, rover localization, remote sensing instrument targeting, and robotic arm placement. Each of these activity types requires a different set of data compression rates, surface coverage, and image acquisition strategies. An overview of the surface imaging activities is provided, along with a summary of the image data acquired to date. ?? 2005 IEEE.
Testing the quantum superposition principle: matter waves and beyond
NASA Astrophysics Data System (ADS)
Ulbricht, Hendrik
2015-05-01
New technological developments allow to explore the quantum properties of very complex systems, bringing the question of whether also macroscopic systems share such features, within experimental reach. The interest in this question is increased by the fact that, on the theory side, many suggest that the quantum superposition principle is not exact, departures from it being the larger, the more macroscopic the system. Testing the superposition principle intrinsically also means to test suggested extensions of quantum theory, so-called collapse models. We will report on three new proposals to experimentally test the superposition principle with nanoparticle interferometry, optomechanical devices and by spectroscopic experiments in the frequency domain. We will also report on the status of optical levitation and cooling experiments with nanoparticles in our labs, towards an Earth bound matter-wave interferometer to test the superposition principle for a particle mass of one million amu (atomic mass unit).
rasdaman Array Database: current status
NASA Astrophysics Data System (ADS)
Merticariu, George; Toader, Alexandru
2015-04-01
rasdaman (Raster Data Manager) is a Free Open Source Array Database Management System which provides functionality for storing and processing massive amounts of raster data in the form of multidimensional arrays. The user can access, process and delete the data using SQL. The key features of rasdaman are: flexibility (datasets of any dimensionality can be processed with the help of SQL queries), scalability (rasdaman's distributed architecture enables it to seamlessly run on cloud infrastructures while offering an increase in performance with the increase of computation resources), performance (real-time access, processing, mixing and filtering of arrays of any dimensionality) and reliability (legacy communication protocol replaced with a new one based on cutting edge technology - Google Protocol Buffers and ZeroMQ). Among the data with which the system works, we can count 1D time series, 2D remote sensing imagery, 3D image time series, 3D geophysical data, and 4D atmospheric and climate data. Most of these representations cannot be stored only in the form of raw arrays, as the location information of the contents is also important for having a correct geoposition on Earth. This is defined by ISO 19123 as coverage data. rasdaman provides coverage data support through the Petascope service. Extensions were added on top of rasdaman in order to provide support for the Geoscience community. The following OGC standards are currently supported: Web Map Service (WMS), Web Coverage Service (WCS), and Web Coverage Processing Service (WCPS). The Web Map Service is an extension which provides zoom and pan navigation over images provided by a map server. Starting with version 9.1, rasdaman supports WMS version 1.3. The Web Coverage Service provides capabilities for downloading multi-dimensional coverage data. Support is also provided for several extensions of this service: Subsetting Extension, Scaling Extension, and, starting with version 9.1, Transaction Extension, which defines request types for inserting, updating and deleting coverages. A web client, designed for both novice and experienced users, is also available for the service and its extensions. The client offers an intuitive interface that allows users to work with multi-dimensional coverages by abstracting the specifics of the standard definitions of the requests. The Web Coverage Processing Service defines a language for on-the-fly processing and filtering multi-dimensional raster coverages. rasdaman exposes this service through the WCS processing extension. Demonstrations are provided online via the Earthlook website (earthlook.org) which presents use-cases from a wide variety of application domains, using the rasdaman system as processing engine.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Liu, Beibei; Zhang, Xiaojia; Lin, Douglas N. C.
2015-01-01
Nearly 15%-20% of solar type stars contain one or more gas giant planets. According to the core-accretion scenario, the acquisition of their gaseous envelope must be preceded by the formation of super-critical cores with masses 10 times or larger than that of the Earth. It is natural to link the formation probability of gas giant planets with the supply of gases and solids in their natal disks. However, a much richer population of super Earths suggests that (1) there is no shortage of planetary building block material, (2) a gas giant's growth barrier is probably associated with whether it can mergemore » into super-critical cores, and (3) super Earths are probably failed cores that did not attain sufficient mass to initiate efficient accretion of gas before it is severely depleted. Here we construct a model based on the hypothesis that protoplanetary embryos migrated extensively before they were assembled into bona fide planets. We construct a Hermite-Embryo code based on a unified viscous-irradiation disk model and a prescription for the embryo-disk tidal interaction. This code is used to simulate the convergent migration of embryos, and their close encounters and coagulation. Around the progenitors of solar-type stars, the progenitor super-critical-mass cores of gas giant planets primarily form in protostellar disks with relatively high (≳ 10{sup –7} M {sub ☉} yr{sup –1}) mass accretion rates, whereas systems of super Earths (failed cores) are more likely to emerge out of natal disks with modest mass accretion rates, due to the mean motion resonance barrier and retention efficiency.« less
NASA Astrophysics Data System (ADS)
Brune, S.; Williams, S.; Müller, D.
2016-12-01
The deep carbon cycle connects CO2 within the atmosphere and oceans to the vast CO2 reservoir in Earth's mantle: subducted lithosphere carries CO2 into the mantle, while extensional plate boundaries and arc volcanoes release it back to Earth's surface. The length of plate boundaries thereby exerts first-order control on global CO2 fluxes on geological time scales. Here we provide a worldwide census of extensional plate boundary length from the Triassic to present day, in one million year time intervals, using a novel analysis technique (Brune et al. 2016, Nature, doi:10.1038/nature18319). The most extensive rift phase during the fragmentation of Pangea occurred in the Cretaceous with extension along the South Atlantic (9700 km) and North Atlantic rifts (9100 km), within East Gondwana (8500 km), and the failed African rift systems (4900 km). The combined extent of these and several smaller rifts amounts to more than 30.000 km of simultaneously active continental rifting. It is well-accepted that volcanoes at plate boundaries release large amounts of CO2 from the Earth's interior. Recent work, however, revealed the importance of deep-cutting faults and diffuse degassing on CO2 emissions in the East African rift (Lee et al. 2016, Nature Geoscience, doi: 10.1038/ngeo2622). Upscaling these measured CO2 fluxes to all concurrently active global rift zones, we compute first-order estimates of total rift-related CO2 degassing rates for the last 240 Myr. Our results show that rift-related CO2 release rates may have reached 600 Mt/yr in the Early Cretaceous, while Cenozoic rates rarely exceeded 200 Mt/yr. By comparison, present-day estimates of CO2 release at mid-ocean ridges range between 53 and 97 Mt/yr. We suggest that rift-related degassing during supercontinental breakup played a major role in maintaining high atmospheric CO2 concentrations through Mesozoic times, which exceeded Quaternary values by 400%.
Earth observations taken during the STS-103 mission
1999-12-24
STS103-710-084 (19-27 December 1999)--- One of the astronauts aboard the Earth-orbiting Space Shuttle Discovery used a handheld 70mm camera to photograph the great sand seas which occupy northern Algeria. They are Grand Erg Oriental (Eastern Sand Sea) and Grand Erg Occidental (Western Sand Sea). Both sand seas occupy depressions that are separated by a north-south rise called Mizab. Ergs are areas of large accumulations of sand that take the form of actively shifting dunes, fossilized dunes, or extensive sand sheets.
DPOD2014: a new DORIS extension of ITRF2014 for Precise Orbit Determination
NASA Astrophysics Data System (ADS)
Moreaux, G.; Willis, P.; Lemoine, F. G.; Zelensky, N. P.
2016-12-01
As one of the tracking systems used to determine orbits of the altimeter mission satellites (such as TOPEX/Poseidon, Envisat, Jason-1/2/3 & Cryosat-2), the position of the DORIS tracking stations provides a fundamental reference for the estimation of the precise orbits and so, by extension is fundamental for the quality of the altimeter data and derived products. Therefore, the time evolution of the position of both the existing and the newest DORIS stations must be precisely modeled and regularly updated. To satisfy operational requirements for precise orbit determination and routine delivery of geodetic products, the International DORIS Service maintains the so-called DPOD solutions, which can be seen as extensions of the latest available ITRF solution from the International Earth Rotation and Reference Systems Service (IERS). In mid-2016, the IDS agreed to change the processing strategy of the DPOD solution. The new solution from the IDS Combination Center (CC) consists of a DORIS cumulative position and velocity solution using the latest IDS combined weekly solutions. The first objective of this study is to describe the new DPOD elaboration scheme and to show the IDS CC internal validation steps. The second purpose is to present the external validation process made by an external team before the new DPOD is made available to all the users. The elaboration and validation procedures will be illustrated by the presentation of first version of the DPOD2014 (ITRF2014 DORIS extension) and focus will be given on the update of the position and velocity of two DORIS sites: Everest (after Gorkha earthquake M7.8 in April 2015) and Thule (Greenland).
Detection of Ultrahigh-Energy Cosmic Rays with the Auger Engineering Radio Array
NASA Astrophysics Data System (ADS)
Krause, Raphael; Pierre Auger Collaboration
2017-02-01
Ultrahigh-energy cosmic rays interact with the Earth's atmosphere and produce great numbers of secondary particles forming an extensive air shower. These air showers emit radiation in the radio frequency range which delivers important information about the processes of radio emission in extensive air showers and properties of the primary cosmic rays, e.g. arrival direction, energy and mass with a duty cycle close to 100%. The radio extension of the world's largest cosmic-ray experiment, the Pierre Auger Observatory, is called the Auger Engineering Radio Array (AERA). In addition to the particle and fluorescence detectors of the Pierre Auger Observatory, AERA investigates the electromagnetic component of extensive air showers using 153 autonomous radio stations on an area of 17km2 .
2015-02-15
ISS042E275153 (02/15/2015) --- Expedition 42 Flight Engineer Terry Virts on the International Space Station tweeted his followers this earth observation image on Feb. 15, 2015. He commented that it was "Extensive #Africa desert of #Libya and #Chad".
Frictional velocity-weakening in landslides on Earth and on other planetary bodies.
Lucas, Antoine; Mangeney, Anne; Ampuero, Jean Paul
2014-03-04
One of the ultimate goals in landslide hazard assessment is to predict maximum landslide extension and velocity. Despite much work, the physical processes governing energy dissipation during these natural granular flows remain uncertain. Field observations show that large landslides travel over unexpectedly long distances, suggesting low dissipation. Numerical simulations of landslides require a small friction coefficient to reproduce the extension of their deposits. Here, based on analytical and numerical solutions for granular flows constrained by remote-sensing observations, we develop a consistent method to estimate the effective friction coefficient of landslides. This method uses a constant basal friction coefficient that reproduces the first-order landslide properties. We show that friction decreases with increasing volume or, more fundamentally, with increasing sliding velocity. Inspired by frictional weakening mechanisms thought to operate during earthquakes, we propose an empirical velocity-weakening friction law under a unifying phenomenological framework applicable to small and large landslides observed on Earth and beyond.
A case of death due to rescue action by a power shovel after being buried alive.
Watanabe-Suzuki, K; Nozawa, H; Ishii, A; Seno, H; Suzuki, O
2001-12-01
We report a rare case of death due to rescue using a power shovel. A 41-year-old female was accidentally buried alive by a landslide of the earth and sand upon working at a construction site. One of her colleagues started to save her using a power shovel. However, she was dug out dead at the spot about 10 min after the accident with marked head and face injuries. The autopsy disclosed that there was extensive laceration across the face and head with marked skull bone fractures. Around these injuries, extensive hemorrhage could be observed as a vital reaction. Asphyxial death had to be taken into consideration, because she was buried under the earth and sand for about 10 min; but we finally judged that the cause of her death was head injury by the power shovel inflicted during the attempted rescue.
NASA Technical Reports Server (NTRS)
Motesharrei, Safa; Rivas, Jorge; Kalnay, Eugenia; Asrar, Ghassem R.; Busalacchi, Antonio J.; Cahalan, Robert F.; Cane, Mark A.; Colwell, Rita R.; Feng, Kuishuang; Franklin, Rachel S.;
2016-01-01
Over the last two centuries, the impact of the Human System has grown dramatically, becoming strongly dominant within the Earth System in many different ways. Consumption, inequality, and population have increased extremely fast, especially since about 1950, threatening to overwhelm the many critical functions and ecosystems of the Earth System. Changes in the Earth System, in turn, have important feedback effects on the Human System, with costly and potentially serious consequences. However, current models do not incorporate these critical feedbacks. We argue that in order to understand the dynamics of either system, Earth System Models must be coupled with Human System Models through bidirectional couplings representing the positive, negative, and delayed feedbacks that exist in the real systems. In particular, key Human System variables, such as demographics, inequality, economic growth, and migration, are not coupled with the Earth System but are instead driven by exogenous estimates, such as UN population projections. This makes current models likely to miss important feedbacks in the real Earth-Human system, especially those that may result in unexpected or counterintuitive outcomes, and thus requiring different policy interventions from current models. The importance and imminence of sustainability challenges, the dominant role of the Human System in the Earth System, and the essential roles the Earth System plays for the Human System, all call for collaboration of natural scientists, social scientists, and engineers in multidisciplinary research and modeling to develop coupled Earth-Human system models for devising effective science-based policies and measures to benefit current and future generations.
NASA Technical Reports Server (NTRS)
Huth, John F.; Whiteley, James D.; Hawker, John E.
1993-01-01
A wide variety of secondary payloads have flown on the Space Transportation System (STS) since its first flight in the 1980's. These experiments have typically addressed specific issues unique to the zero-gravity environment. Additionally, the experiments use the experience and skills of the mission and payload specialist crew members to facilitate data collection and ensure successful completion. This paper presents the results of the Terra Scout experiment, which flew aboard STS-44 in November 1991. This unique Earth Observation experiment specifically required a career imagery analyst to operate the Spaceborne Direct-View Optical System (SpaDVOS), a folded optical path telescope system designed to mount inside the shuttle on the overhead aft flight deck windows. Binoculars and a small telescope were used as backup optics. Using his imagery background, coupled with extensive target and equipment training, the payload specialist was tasked with documenting the following: (1) the utility of the equipment; (2) his ability to acquire and track ground targets; (3) the level of detail he could discern; (4) the atmospheric conditions; and (5) other in-situ elements which contributed to or detracted from his ability to analyze targets. Special emphasis was placed on the utility of a manned platform for research and development of future spaceborne sensors. The results and lessons learned from Terra Scout will be addressed including human performance and equipment design issues.
NASA Technical Reports Server (NTRS)
Wood, C. A.; Helfert, M. R.; Lulla, K. P.; Covey, R. O.
1989-01-01
During the late September-early October, 1988 flight of the Space Shuttle Discovery, astronauts took 1505 photographs of earth using handheld cameras. The resulting pictures provide an overview, not available from any other source, of dynamic environmental phenomena on five continents. The Discovery photographs show that: (1) atmospheric clarity has improved in the Northern Hemisphere, (2) widespread burning of natural vegetation throughout the Southern Hemisphere continues to generate immense smoke palls and extensive sedimentation in rivers and estuaries, and (3) although the drought in Africa was partially relieved by heavy rains in autumn, 1988, Lakes Chad and Nasser are at the lowest levels ever seen from space.
NASA Astrophysics Data System (ADS)
Adams, P. E.
2009-12-01
Earth system science is an often neglected subject in the US science curriculum. The state of Kansas State Department of Education, for example, has provided teachers with a curriculum guide for incorporating earth system science as an ancillary topic within the subjects of physics, chemistry, and the biological sciences. While this does provide a means to have earth system science within the curriculum, it relegates earth system science topics to a secondary status. In practice, earth system science topics are considered optional or only taught if there is time within an already an overly crowded curriculum. Given the importance of developing an educated citizenry that is capable of understanding, coping, and deciding how to live in a world where climate change is a reality requires a deeper understanding of earth system science. The de-emphasis of earth system science in favor of other science disciplines makes it imperative to seek opportunities to provide teachers, whose primary subject is not earth system science, with professional development opportunities to develop content knowledge understanding of earth system science, and pedagogical content knowledge (i.e. effective strategies for teaching earth system science). This is a noble goal, but there is no single method. At Fort Hays State University we have developed multiple strategies from face-to-face workshops, on-line coursework, and academic year virtual and face-to-face consultations with in-service and pre-service teachers. A review of the techniques and measures of effectiveness (based on teacher and student performance), and strengths and limitations of each method will be presented as an aid to other institutions and programs seeking to improve the teaching and learning of earth system science in their region.
Material exposure effects in a simulated low-Earth orbit environment
NASA Astrophysics Data System (ADS)
Maldonado, C.; McHarg, G.; Asmolova, O.; Andersen, G.; Rodrigues, S.; Ketsdever, A.
2016-11-01
Spacecraft operating in low-Earth orbit (LEO) are subjected to a number of hazardous environmental constituents that can lead to decreased system performance and reduced operational lifetimes. Due to their thermal, optical, and mechanical properties, polymers are used extensively in space systems; however they are particularly susceptible to material erosion and degradation as a result of exposure to the LEO environment. The focus of this research is to examine the material erosion and mass loss experienced by the Novastrat 500 polyimide due to exposure in a simulated LEO environment. In addition to the polymer samples, chrome, silver and gold specimens will be examined to measure the oxidation rate and act as a control specimen, respectively. A magnetically filtered atomic oxygen plasma source has previously been developed and characterized for the purpose of simulating the low-Earth orbit environment. The plasma source can be operated at a variety of discharge currents and gas flow rates, of which the plasma parameters downstream of the source are dependent. The characteristics of the generated plasma were examined as a function of these operating parameters to optimize the production of O+ ions with energy relevant to LEO applications, where the ram energy of the ions due to the motion of the satellite relative to the LEO plasma is high (e.g. 7800 m/s, which corresponds to approximately 5 eV of kinetic energy for O+ ions). The plasma downstream of the source consists of streaming ions with energy of approximately 5 eV and an ion species fraction that is approximately 90% O+.
NASA's Earth Science Data Systems - Lessons Learned and Future Directions
NASA Technical Reports Server (NTRS)
Ramapriyan, Hampapuram K.
2010-01-01
In order to meet the increasing demand for Earth Science data, NASA has significantly improved the Earth Science Data Systems over the last two decades. This improvement is reviewed in this slide presentation. Many Earth Science disciplines have been able to access the data that is held in the Earth Observing System (EOS) Data and Information System (EOSDIS) at the Distributed Active Archive Centers (DAACs) that forms the core of the data system.
Monitoring the ionosphere during the earthquake on GPS data
NASA Astrophysics Data System (ADS)
Smirnov, V. M.; Smirnova, E. V.
The problem of stability estimation of physical state of an atmosphere attracts a rapt attention of the world community but it is still far from being solved A lot of global atmospheric processes which have direct influence upon all forms of the earth life have been detected The comprehension of cause effect relations stipulating their origin and development is possible only on the basis of long-term sequences of observations data of time-space variations of the atmosphere characteristics which should be received on a global scale and in the interval of altitudes as brand as possible Such data can be obtained only with application satellite systems The latest researches have shown that the satellite systems can be successfully used for global and continuous monitoring ionosphere of the Earth In turn the ionosphere can serve a reliable indicator of different kinds of effects on an environment both of natural and anthropogenic origin Nowadays the problem of the short-term forecast of earthquakes has achieved a new level of understanding There have been revealed indisputable factors which show that the ionosphere anomalies observed during the preparation of seismic events contain the information allowing to detect and to interpret them as earthquake precursors The partial decision of the forecast problem of earthquakes on ionospheric variations requires the processing data received simultaneously from extensive territories Such requirements can be met only on the basis of ground-space system of ionosphere monitoring The navigating systems
NASA Astrophysics Data System (ADS)
Larour, Eric; Cheng, Daniel; Perez, Gilberto; Quinn, Justin; Morlighem, Mathieu; Duong, Bao; Nguyen, Lan; Petrie, Kit; Harounian, Silva; Halkides, Daria; Hayes, Wayne
2017-12-01
Earth system models (ESMs) are becoming increasingly complex, requiring extensive knowledge and experience to deploy and use in an efficient manner. They run on high-performance architectures that are significantly different from the everyday environments that scientists use to pre- and post-process results (i.e., MATLAB, Python). This results in models that are hard to use for non-specialists and are increasingly specific in their application. It also makes them relatively inaccessible to the wider science community, not to mention to the general public. Here, we present a new software/model paradigm that attempts to bridge the gap between the science community and the complexity of ESMs by developing a new JavaScript application program interface (API) for the Ice Sheet System Model (ISSM). The aforementioned API allows cryosphere scientists to run ISSM on the client side of a web page within the JavaScript environment. When combined with a web server running ISSM (using a Python API), it enables the serving of ISSM computations in an easy and straightforward way. The deep integration and similarities between all the APIs in ISSM (MATLAB, Python, and now JavaScript) significantly shortens and simplifies the turnaround of state-of-the-art science runs and their use by the larger community. We demonstrate our approach via a new Virtual Earth System Laboratory (VESL) website (http://vesl.jpl.nasa.gov, VESL(2017)).
Analysis of a generalized dual reflector antenna system using physical optics
NASA Technical Reports Server (NTRS)
Acosta, Roberto J.; Lagin, Alan R.
1992-01-01
Reflector antennas are widely used in communication satellite systems because they provide high gain at low cost. Offset-fed single paraboloids and dual reflector offset Cassegrain and Gregorian antennas with multiple focal region feeds provide a simple, blockage-free means of forming multiple, shaped, and isolated beams with low sidelobes. Such antennas are applicable to communications satellite frequency reuse systems and earth stations requiring access to several satellites. While the single offset paraboloid has been the most extensively used configuration for the satellite multiple-beam antenna, the trend toward large apertures requiring minimum scanned beam degradation over the field of view 18 degrees for full earth coverage from geostationary orbit may lead to impractically long focal length and large feed arrays. Dual reflector antennas offer packaging advantages and more degrees of design freedom to improve beam scanning and cross-polarization properties. The Cassegrain and Gregorian antennas are the most commonly used dual reflector antennas. A computer program for calculating the secondary pattern and directivity of a generalized dual reflector antenna system was developed and implemented at LeRC. The theoretical foundation for this program is based on the use of physical optics methodology for describing the induced currents on the sub-reflector and main reflector. The resulting induced currents on the main reflector are integrated to obtain the antenna far-zone electric fields. The computer program is verified with other physical optics programs and with measured antenna patterns. The comparison shows good agreement in far-field sidelobe reproduction and directivity.
NASA Astrophysics Data System (ADS)
Liu, D.; Zeren, Z.; Du, C.; Feng, L.; Nima, C.; Zhang, L.
2012-12-01
With the collision of Indian plate and Eura-Asian plate, there developed complicated tectono-magmanism during Meso-Cenozoic in Gangdese belt, Xizang Tibet. Therefore, it resulted that plentiful tectonism and post-collision high-K calc-alkaline magmatism related to mineralization distrubted from east to west in the belt. And this is quite significant for us to do some rearch on large-scale metallogenetics, uplifting epoch and EW-striking extension during the post-collision in Xizang-Qinghai Plateau. Zircon samples from Cangrila Granodiorite-porphyry in Qulong area, Southeast of Gangdese porphyry copper belt, Xiangbeishan diorite-porphyrite and from Jiama Granite-porphyry give LA-ICPMS U-Pb ages of 16.3Ma, 14. 4Ma, and 15.4Ma, respectively, and all these ages represent the porphyries' forming ages. From barren Xiangbeishan diorite-porphyrite through intermediately mineralized Jiama Granite-porphyry to stongly mineralized Cangrila Granodiorite-porphyry, the LA-ICPMS U-Pb ages of zircon become younger and younger. According to the regional data and geochemical characteristics, these porphyries were mainly derived directly from the thickened mafic lower-crust formed in south Tibet during collision and epeirogeny. During post-collisional extension stage, for inter-earth thermal flowing, SN-striking normal faulting systems across the Tibetan orogen caused rapid rising and localization of porphyry magmas and adequately separating of massive ore-bearing fluids from the magmatic hydrothermal systems. All these data indicate that Gandese belt has experienced from post-collisional extrusion changed into intra-plate extension since Miocene. During Miocene, Gangdese belt undergone violent intraplate extension, post-collisional porphyry intrusion and paroxysmal massive mineralization of porphyry-type, and all these was controlled by deep dynamics. Key Words: Qulong area; Gangdese tectonic belt; Tibet;Zircon La-ICP-MS U-Pb dating; intra-plate extension; Image Information For CL images of zircon grains from porphyries
Spatio-temporal analysis of aftershock sequences in terms of Non Extensive Statistical Physics.
NASA Astrophysics Data System (ADS)
Chochlaki, Kalliopi; Vallianatos, Filippos
2017-04-01
Earth's seismicity is considered as an extremely complicated process where long-range interactions and fracturing exist (Vallianatos et al., 2016). For this reason, in order to analyze it, we use an innovative methodological approach, introduced by Tsallis (Tsallis, 1988; 2009), named Non Extensive Statistical Physics. This approach introduce a generalization of the Boltzmann-Gibbs statistical mechanics and it is based on the definition of Tsallis entropy Sq, which maximized leads the the so-called q-exponential function that expresses the probability distribution function that maximizes the Sq. In the present work, we utilize the concept of Non Extensive Statistical Physics in order to analyze the spatiotemporal properties of several aftershock series. Marekova (Marekova, 2014) suggested that the probability densities of the inter-event distances between successive aftershocks follow a beta distribution. Using the same data set we analyze the inter-event distance distribution of several aftershocks sequences in different geographic regions by calculating non extensive parameters that determine the behavior of the system and by fitting the q-exponential function, which expresses the degree of non-extentivity of the investigated system. Furthermore, the inter-event times distribution of the aftershocks as well as the frequency-magnitude distribution has been analyzed. The results supports the applicability of Non Extensive Statistical Physics ideas in aftershock sequences where a strong correlation exists along with memory effects. References C. Tsallis, Possible generalization of Boltzmann-Gibbs statistics, J. Stat. Phys. 52 (1988) 479-487. doi:10.1007/BF01016429 C. Tsallis, Introduction to nonextensive statistical mechanics: Approaching a complex world, 2009. doi:10.1007/978-0-387-85359-8. E. Marekova, Analysis of the spatial distribution between successive earthquakes in aftershocks series, Annals of Geophysics, 57, 5, doi:10.4401/ag-6556, 2014 F. Vallianatos, G. Papadakis, G. Michas, Generalized statistical mechanics approaches to earthquakes and tectonics. Proc. R. Soc. A, 472, 20160497, 2016.
NASA Astrophysics Data System (ADS)
Karakatsanis, L. P.; Iliopoulos, A. C.; Pavlos, E. G.; Pavlos, G. P.
2018-02-01
In this paper, we perform statistical analysis of time series deriving from Earth's climate. The time series are concerned with Geopotential Height (GH) and correspond to temporal and spatial components of the global distribution of month average values, during the period (1948-2012). The analysis is based on Tsallis non-extensive statistical mechanics and in particular on the estimation of Tsallis' q-triplet, namely {qstat, qsens, qrel}, the reconstructed phase space and the estimation of correlation dimension and the Hurst exponent of rescaled range analysis (R/S). The deviation of Tsallis q-triplet from unity indicates non-Gaussian (Tsallis q-Gaussian) non-extensive character with heavy tails probability density functions (PDFs), multifractal behavior and long range dependences for all timeseries considered. Also noticeable differences of the q-triplet estimation found in the timeseries at distinct local or temporal regions. Moreover, in the reconstructive phase space revealed a lower-dimensional fractal set in the GH dynamical phase space (strong self-organization) and the estimation of Hurst exponent indicated multifractality, non-Gaussianity and persistence. The analysis is giving significant information identifying and characterizing the dynamical characteristics of the earth's climate.
Venus tectonics: initial analysis from magellan.
Solomon, S C; Head, J W; Kaula, W M; McKenzie, D; Parsons, B; Phillips, R J; Schubert, G; Talwani, M
1991-04-12
Radar imaging and altimetry data from the Magellan mission have revealed a diversity of deformational features at a variety of spatial scales on the Venus surface. The plains record a superposition of different episodes of deformation and volcanism; strain is both areally distributed and concentrated into zones of extension and shortening. The common coherence of strain patterns over hundreds of kilometers implies that many features in the plains reflect a crustal response to mantle dynamic processes. Ridge belts and mountain belts represent successive degrees of lithospheric shortening and crustal thickening; the mountain belts also show widespread evidence for extension and collapse both during and following crustal compression. Venus displays two geometrical patterns of concentrated lithospheric extension: quasi-circular coronae and broad rises with linear rift zones; both are sites of significant volcanism. No long, large-offset strike-slip faults have been observed, although limited local horizontal shear is accommodated across many zones of crustal shortening. In general, tectonic features on Venus are unlike those in Earth's oceanic regions in that strain typically is distributed across broad zones that are one to a few hundred kilometers wide, and separated by stronger and less deformed blocks hundreds of kilometers in width, as in actively deforming continental regions on Earth.
Release of Nitrogen during Planetary Accretion Explains Missing Nitrogen in Earth's Mantle
NASA Astrophysics Data System (ADS)
Liu, J.; Dorfman, S.; Lv, M.; Li, J.; Kono, Y.
2017-12-01
Nitrogen and carbon are essential elements for life on Earth, and their relative abundances in planetary bodies (C/N ratios) are important for understanding planetary evolution and habitability1,2. However, the high C/N ratio in the bulk silicate Earth relative to CI chondrites and other volatile-rich chondrites is difficult to explain with partitioning behavior between silicate and metallic liquid or solubility in silicate melt, and has thus been a major unsolved problem in geochemistry1-5. Because core formation does not explain nitrogen depletion in the mantle, another process is required to match the observed BSE C/N ratio, such as devolatilization of metallic liquid. Previous studies have examined the Fe-C phase diagram extensively (e.g. ref. 6), but very limited melting data is available for the Fe-N system7. Here we examine melting relations for four Fe-N-C compositions with 1-7 wt% nitrogen up to 7 GPa and 2200 K in the Paris-Edinburgh press by a combination of in-situ X-ray radiography, X-ray diffraction and ex-situ electron microprobe techniques. In striking contrast to the Fe-C system, near-surface melting in all compositions in the Fe-N-C system entails release of nitrogen fluid and depletion of nitrogen from the liquid alloy. This could provide a pathway for nitrogen to escape the magma ocean in the accretion stage while carbon is retained. On the basis of our experimental results, we propose a new quantitative model of mantle nitrogen evolution during the core formation stage to explain the high BSE C/N ratios and resolve the paradox of missing mantle nitrogen1-5. Although nitrogen itself is not a greenhouse gas, the nitrogen released to the atmosphere from metallic melt early in Earth's history could amplify the greenhouse effect through collision-enhanced absorption8,9, which may help to explain warm surface temperatures during the Hadean and Archean eras on Earth when the solar luminosity was 25-30% lower than the present10. References1. Bergin et al., PNAS (2015). 2. Hirschmann, Am. Mineral. (2016). 3. Marty, EPSL (2012). 4. Halliday, GCA (2013). 5. Dalou et al., EPSL (2017). 6. Walker et al., Contrib. Mineral. Petrol. (2013). 7. Guillermet et al., Z. Metallkd. (1994). 8. Wordsworth et al., Science (2013). 9. Goldblatt et al. Nat. Geosci. (2009). 10. Gough. Sol. Phys. (1981)
Supporting Data Stewardship Throughout the Data Life Cycle in the Solid Earth Sciences
NASA Astrophysics Data System (ADS)
Ferrini, V.; Lehnert, K. A.; Carbotte, S. M.; Hsu, L.
2013-12-01
Stewardship of scientific data is fundamental to enabling new data-driven research, and ensures preservation, accessibility, and quality of the data, yet researchers, especially in disciplines that typically generate and use small, but complex, heterogeneous, and unstructured datasets are challenged to fulfill increasing demands of properly managing their data. The IEDA Data Facility (www.iedadata.org) provides tools and services that support data stewardship throughout the full life cycle of observational data in the solid earth sciences, with a focus on the data management needs of individual researchers. IEDA builds upon and brings together over a decade of development and experiences of its component data systems, the Marine Geoscience Data System (MGDS, www.marine-geo.org) and EarthChem (www.earthchem.org). IEDA services include domain-focused data curation and synthesis, tools for data discovery, access, visualization and analysis, as well as investigator support services that include tools for data contribution, data publication services, and data compliance support. IEDA data synthesis efforts (e.g. PetDB and Global Multi-Resolution Topography (GMRT) Synthesis) focus on data integration and analysis while emphasizing provenance and attribution. IEDA's domain-focused data catalogs (e.g. MGDS and EarthChem Library) provide access to metadata-rich long-tail data complemented by extensive metadata including attribution information and links to related publications. IEDA's visualization and analysis tools (e.g. GeoMapApp) broaden access to earth science data for domain specialist and non-specialists alike, facilitating both interdisciplinary research and education and outreach efforts. As a disciplinary data repository, a key role IEDA plays is to coordinate with its user community and to bridge the requirements and standards for data curation with both the evolving needs of its science community and emerging technologies. Development of IEDA tools and services is based first and foremost on the scientific needs of its user community. As data stewardship becomes a more integral component of the scientific workflow, IEDA investigator support services (e.g. Data Management Plan Tool and Data Compliance Reporting Tool) continue to evolve with the goal of lessening the 'burden' of data management for individual investigators by increasing awareness and facilitating the adoption of data management practices. We will highlight a variety of IEDA system components that support investigators throughout the data life cycle, and will discuss lessons learned and future directions.
Lidar instruments for ESA Earth observation missions
NASA Astrophysics Data System (ADS)
Hélière, Arnaud; Armandillo, Errico; Durand, Yannig; Culoma, Alain; Meynart, Roland
2017-11-01
The idea of deploying a lidar system on an Earthorbiting satellite stems from the need for continuously providing profiles of our atmospheric structure with high accuracy and resolution and global coverage. Interest in this information for climatology, meteorology and the atmospheric sciences in general is huge. Areas of application range from the determination of global warming and greenhouse effects, to monitoring the transport and accumulation of pollutants in the different atmospheric regions (such as the recent fires in Southeast Asia), to the assessment of the largely unknown microphysical properties and the structural dynamics of the atmosphere itself. Spaceborne lidar systems have been the subject of extensive investigations by the European Space Agency since mid 1970's, resulting in mission and instrument concepts, such as ATLID, the cloud backscatter lidar payload of the EarthCARE mission, ALADIN, the Doppler wind lidar of the Atmospheric Dynamics Mission (ADM) and more recently a water vapour Differential Absorption Lidar considered for the WALES mission. These studies have shown the basic scientific and technical feasibility of spaceborne lidars, but they have also demonstrated their complexity from the instrument viewpoint. As a result, the Agency undertook technology development in order to strengthen the instrument maturity. This is the case for ATLID, which benefited from a decade of technology development and supporting studies and is now studied in the frame of the EarthCARE mission. ALADIN, a Direct Detection Doppler Wind Lidar operating in the Ultra -Violet, will be the 1st European lidar to fly in 2007 as payload of the Earth Explorer Core Mission ADM. WALES currently studied at the level of a phase A, is based upon a lidar operating at 4 wavelengths in near infrared and aims to profile the water vapour in the lower part of the atmosphere with high accuracy and low bias. Lastly, the European Space Agency is extending the lidar instrument field for Earth Observation by initiating feasibility studies of a spaceborne concept to monitor atmospheric CO2 and other greenhouse gases. The purpose of this paper is to present the instruments concept and related technology/instrument developments that are currently running at the European Space Agency. The paper will also outline the development planning proposed for future lidar systems.
Understanding our Changing Planet: NASA's Earth Science Enterprise
NASA Technical Reports Server (NTRS)
Forehand, Lon; Griner, Charlotte (Editor); Greenstone, Renny (Editor)
1999-01-01
NASA has been studying the Earth and its changing environment by observing the atmosphere, oceans, land, ice, and snow and their influence on climate and weather since the agency's creation. This study has lead to a new approach to understanding the interaction of the Earth's systems, Earth System Science. The Earth Science Enterprise, NASA's comprehensive program for Earth System Science, uses satellites and other tools to intensively study the Earth. The Earth Science Enterprise has three main components: (1) a series of Earth-observing satellites, (2) an advanced data system and (3) teams of scientist who study the data. Key areas of study include: (1) clouds, (2) water and energy cycles, (3) oceans, (4) chemistry of the atmosphere, (5) land surface, water and ecosystems processes; (6) glaciers and polar ice sheets, and (7) the solid earth.
Key Provenance of Earth Science Observational Data Products
NASA Astrophysics Data System (ADS)
Conover, H.; Plale, B.; Aktas, M.; Ramachandran, R.; Purohit, P.; Jensen, S.; Graves, S. J.
2011-12-01
As the sheer volume of data increases, particularly evidenced in the earth and environmental sciences, local arrangements for sharing data need to be replaced with reliable records about the what, who, how, and where of a data set or collection. This is frequently called the provenance of a data set. While observational data processing systems in the earth sciences have a long history of capturing metadata about the processing pipeline, current processes are limited in both what is captured and how it is disseminated to the science community. Provenance capture plays a role in scientific data preservation and stewardship precisely because it can automatically capture and represent a coherent picture of the what, how and who of a particular scientific collection. It reflects the transformations that a data collection underwent prior to its current form and the sequence of tasks that were executed and data products applied to generate a new product. In the NASA-funded Instant Karma project, we examine provenance capture in earth science applications, specifically the Advanced Microwave Scanning Radiometer - Earth Observing System (AMSR-E) Science Investigator-led Processing system (SIPS). The project is integrating the Karma provenance collection and representation tool into the AMSR-E SIPS production environment, with an initial focus on Sea Ice. This presentation will describe capture and representation of provenance that is guided by the Open Provenance Model (OPM). Several things have become clear during the course of the project to date. One is that core OPM entities and relationships are not adequate for expressing the kinds of provenance that is of interest in the science domain. OPM supports name-value pair annotations that can be used to augment what is known about the provenance entities and relationships, but in Karma, annotations cannot be added during capture, but only after the fact. This limits the capture system's ability to record something it learned about an entity after the event of its creation in the provenance record. We will discuss extensions to the Open Provenance Model (OPM) and modifications to the Karma tool suite to address this issue, more efficient representations of earth science kinds of provenance, and definition of metadata structures for capturing related knowledge about the data products and science algorithms used to generate them. Use scenarios for provenance information is an active topic of investigation. It has additionally become clear through the project that not all provenance is created equal. In processing pipelines, some provenance is repetitive and uninteresting. Because of the volume of provenance, this obscures what are the interesting pieces of provenance. Methodologies to reveal science-relevant provenance will be presented, along with a preview of the AMSR-E Provenance Browser.
Automating U-Pb IDTIMS data reduction and reporting: Cyberinfrastructure meets geochronology
NASA Astrophysics Data System (ADS)
Bowring, J. F.; McLean, N.; Walker, J. D.; Ash, J. M.
2009-12-01
We demonstrate the efficacy of an interdisciplinary effort between software engineers and geochemists to produce working cyberinfrastructure for geochronology. This collaboration between CIRDLES, EARTHTIME and EarthChem has produced the software programs Tripoli and U-Pb_Redux as the cyber-backbone for the ID-TIMS community. This initiative incorporates shared isotopic tracers, data-reduction algorithms and the archiving and retrieval of data and results. The resulting system facilitates detailed inter-laboratory comparison and a new generation of cooperative science. The resolving power of geochronological data in the earth sciences is dependent on the precision and accuracy of many isotopic measurements and corrections. Recent advances in U-Pb geochronology have reinvigorated its application to problems such as precise timescale calibration, processes of crustal evolution, and early solar system dynamics. This project provides a heretofore missing common data reduction protocol, thus promoting the interpretation of precise geochronology and enabling inter-laboratory comparison. U-Pb_Redux is an open-source software program that provides end-to-end support for the analysis of uranium-lead geochronological data. The system reduces raw mass spectrometer data to U-Pb dates, allows users to interpret ages from these data, and then provides for the seamless federation of the results, coming from many labs, into a community web-accessible database using standard and open techniques. This EarthChem GeoChron database depends also on keyed references to the SESAR sample database. U-Pb_Redux currently provides interactive concordia and weighted mean plots and uncertainty contribution visualizations; it produces publication-quality concordia and weighted mean plots and customizable data tables. This initiative has achieved the goal of standardizing the data elements of a complete reduction and analysis of uranium-lead data, which are expressed using extensible markup language schema definition (XSD) artifacts. U-Pb_Redux leverages the freeware program Tripoli, which imports raw mass spectrometer data files and supports interactive review and archiving of isotopic data. Tripoli facilitates the visualization of temporal trends and scatter during measurement, statistically rigorous filtering of data and supports oxide and fractionation corrections. The Cyber Infrastructure Research and Development Lab for the Earth Sciences (CIRDLES) collaboratively integrates domain-specific software engineering with the efforts EARTHTIME and Earthchem. The EARTHTIME initiative pursues consensus-based approaches to geochemical data reduction, and the EarthChem initiative pursues the creation of data repositories for all geochemical data. CIRDLES develops software and systems for geochronology. This collaboration benefits the earth sciences by enabling geochemists to focus on their specialties using robust software that produces reliable results. This collaboration benefits software engineering by providing research opportunities to improve process methodologies used in the design and implementation of domain-specific solutions.
Vector Data Model: A New Model of HDF-EOS to Support GIS Applications in EOS
NASA Astrophysics Data System (ADS)
Chi, E.; Edmonds, R d
2001-05-01
NASA's Earth Science Data Information System (ESDIS) project has an active program of research and development of systems for the storage and management of Earth science data for Earth Observation System (EOS) mission, a key program of NASA Earth Science Enterprise. EOS has adopted an extension of the Hierarchical Data Format (HDF) as the format of choice for standard product distribution. Three new EOS specific datatypes - point, swath and grid - have been defined within the HDF framework. The enhanced data format is named HDF-EOS. Geographic Information Systems (GIS) are used by Earth scientists in EOS data product generation, visualization, and analysis. There are two major data types in GIS applications, raster and vector. The current HDF-EOS handles only raster type in the swath data model. The vector data model is identified and developed as a new HDFEOS format to meet the requirements of scientists working with EOS data products in vector format. The vector model is designed using a topological data structure, which defines the spatial relationships among points, lines, and polygons. The three major topological concepts that the vector model adopts are: a) lines connect to each other at nodes (connectivity), b) lines that connect to surround an area define a polygon (area definition), and c) lines have direction and left and right sides (contiguity). The vector model is implemented in HDF by mapping the conceptual model to HDF internal data models and structures, viz. Vdata, Vgroup, and their associated attribute structures. The point, line, and polygon geometry and attribute data are stored in similar tables. Further, the vector model utilizes the structure and product metadata, which characterize the HDF-EOS. Both types of metadata are stored as attributes in HDF-EOS files, and are encoded in text format by using Object Description Language (ODL) and stored as global attributes in HDF-EOS files. EOS has developed a series of routines for storing, retrieving, and manipulating vector data in category of access, definition, basic I/O, inquiry, and subsetting. The routines are tested and form a package, HDF-EOS/Vector. The alpha version of HDFEOS/Vector has been distributed through the HDF-EOS project web site at http://hdfeos.gsfc.nasa.gov. We are also developing translators between HDF-EOS vector format and variety of GIS formats, such as Shapefile. The HDF-EOS vector model enables EOS scientists to deliver EOS data in a way ready for Earth scientists to analyze using GIS software, and also provides EOS project a mechanism to store GIS data product in meaningful vector format with significant economy in storage.
Earth observing system: 1989 reference handbook
NASA Technical Reports Server (NTRS)
1989-01-01
NASA is studying a coordinated effort called the Mission to Planet Earth to understand global change. The goals are to understand the Earth as a system, and to determine those processes that contribute to the environmental balance, as well as those that may result in changes. The Earth Observing System (Eos) is the centerpiece of the program. Eos will create an integrated scientific observing system that will enable multidisciplinary study of the Earth including the atmosphere, oceans, land surface, polar regions, and solid Earth. Science goals, the Eos data and information system, experiments, measuring instruments, and interdisciplinary investigations are described.
The stable Cr isotopic compositions of chondrites and silicate planetary reservoirs
NASA Astrophysics Data System (ADS)
Schoenberg, Ronny; Merdian, Alexandra; Holmden, Chris; Kleinhanns, Ilka C.; Haßler, Kathrin; Wille, Martin; Reitter, Elmar
2016-06-01
The depletion of chromium in Earth's mantle (∼2700 ppm) in comparison to chondrites (∼4400 ppm) indicates significant incorporation of chromium into the core during our planet's metal-silicate differentiation, assuming that there was no significant escape of the moderately volatile element chromium during the accretionary phase of Earth. Stable Cr isotope compositions - expressed as the ‰-difference in 53Cr/52Cr from the terrestrial reference material SRM979 (δ53/52CrSRM979 values) - of planetary silicate reservoirs might thus yield information about the conditions of planetary metal segregation processes when compared to chondrites. The stable Cr isotopic compositions of 7 carbonaceous chondrites, 11 ordinary chondrites, 5 HED achondrites and 2 martian meteorites determined by a double spike MC-ICP-MS method are within uncertainties indistinguishable from each other and from the previously determined δ53/52CrSRM979 value of -0.124 ± 0.101‰ for the igneous silicate Earth. Extensive quality tests support the accuracy of the stable Cr isotope determinations of various meteorites and terrestrial silicates reported here. The uniformity in stable Cr isotope compositions of samples from planetary silicate mantles and undifferentiated meteorites indicates that metal-silicate differentiation of Earth, Mars and the HED parent body did not cause measurable stable Cr isotope fractionation between these two reservoirs. Our results also imply that the accretionary disc, at least in the inner solar system, was homogeneous in its stable Cr isotopic composition and that potential volatility loss of chromium during accretion of the terrestrial planets was not accompanied by measurable stable isotopic fractionation. Small but reproducible variations in δ53/52CrSRM979 values of terrestrial magmatic rocks point to natural stable Cr isotope variations within Earth's silicate reservoirs. Further and more detailed studies are required to investigate whether silicate differentiation processes, such as partial mantle melting and crystal fractionation, can cause stable Cr isotopic fractionation on Earth and other planetary bodies.
NASA Technical Reports Server (NTRS)
Zell, E.; Engel-Cox, J.
2005-01-01
Effective management of energy resources is critical for the U.S. economy, the environment, and, more broadly, for sustainable development and alleviating poverty worldwide. The scope of energy management is broad, ranging from energy production and end use to emissions monitoring and mitigation and long-term planning. Given the extensive NASA Earth science research on energy and related weather and climate-related parameters, and rapidly advancing energy technologies and applications, there is great potential for increased application of NASA Earth science research to selected energy management issues and decision support tools. The NASA Energy Management Program Element is already involved in a number of projects applying NASA Earth science research to energy management issues, with a focus on solar and wind renewable energy and developing interests in energy modeling, short-term load forecasting, energy efficient building design, and biomass production.
Supernova SN 2011fe from an exploding carbon-oxygen white dwarf star.
Nugent, Peter E; Sullivan, Mark; Cenko, S Bradley; Thomas, Rollin C; Kasen, Daniel; Howell, D Andrew; Bersier, David; Bloom, Joshua S; Kulkarni, S R; Kandrashoff, Michael T; Filippenko, Alexei V; Silverman, Jeffrey M; Marcy, Geoffrey W; Howard, Andrew W; Isaacson, Howard T; Maguire, Kate; Suzuki, Nao; Tarlton, James E; Pan, Yen-Chen; Bildsten, Lars; Fulton, Benjamin J; Parrent, Jerod T; Sand, David; Podsiadlowski, Philipp; Bianco, Federica B; Dilday, Benjamin; Graham, Melissa L; Lyman, Joe; James, Phil; Kasliwal, Mansi M; Law, Nicholas M; Quimby, Robert M; Hook, Isobel M; Walker, Emma S; Mazzali, Paolo; Pian, Elena; Ofek, Eran O; Gal-Yam, Avishay; Poznanski, Dovi
2011-12-14
Type Ia supernovae have been used empirically as 'standard candles' to demonstrate the acceleration of the expansion of the Universe even though fundamental details, such as the nature of their progenitor systems and how the stars explode, remain a mystery. There is consensus that a white dwarf star explodes after accreting matter in a binary system, but the secondary body could be anything from a main-sequence star to a red giant, or even another white dwarf. This uncertainty stems from the fact that no recent type Ia supernova has been discovered close enough to Earth to detect the stars before explosion. Here we report early observations of supernova SN 2011fe in the galaxy M101 at a distance from Earth of 6.4 megaparsecs. We find that the exploding star was probably a carbon-oxygen white dwarf, and from the lack of an early shock we conclude that the companion was probably a main-sequence star. Early spectroscopy shows high-velocity oxygen that slows rapidly, on a timescale of hours, and extensive mixing of newly synthesized intermediate-mass elements in the outermost layers of the supernova. A companion paper uses pre-explosion images to rule out luminous red giants and most helium stars as companions to the progenitor.
NASA Astrophysics Data System (ADS)
Burns, A. G.; Eastes, R.
2017-12-01
The GOLD mission of opportunity will fly a far ultraviolet imaging spectrograph in geostationary (GEO) orbit as a hosted payload. The mission is scheduled for launch in late January 2018 on SES-14, a commercial communications satellite that will be stationed over eastern South America at 47.5 degrees west longitude. GOLD is on schedule to be the first NASA science mission to fly as a hosted payload on a commercial communications satellite. The GOLD imager has two identical channels. Each channel can scan the full disk at a 30 minute cadence, making spectral images of Earth's UV emission from 132 to 162 nm, as well as make a measurement on the Earth's limb. Remote sensing techniques that have been proven on previous Low Earth Orbit (LEO) missions will be used to derive fundamental parameters for the neutral and ionized space environment. Parameters that will be derived include composition (O/N2 ratio) and temperature of the neutral atmosphere on the dayside disk. On the nightside, peak electron densities will be obtained in the low latitude ionosphere. Many of the algorithms developed for the mission are extensions of ones used on previous earth and planetary missions, with modifications for observations from geostationary orbit. All the algorithms have been tested using simulated observations based on the actual instrument performance. From geostationary orbit, GOLD can repeatedly image the same geographic locations over most of the hemisphere at a cadence comparable to that of the T-I system (order of an hour). Such time resolution and spatial coverage will allow the mission to track the changes due to geomagnetic storms, variations in solar extreme ultraviolet radiation, and forcing from the lower atmosphere. In addition to providing a new perspective by being able to repeatedly remotely sense the same hemisphere at a high cadence, GOLD's simultaneous measurements of not only composition but also temperatures across the disk will provide a valuable, new parameter for understanding of how the T-I system responds to forcing from both the sun and the lower atmosphere.
ASCANS Class of 2013 Tour CCAFS
2014-03-04
CAPE CANAVERAL, Fla. – NASA astronaut candidates enter the blockhouse at Complex 14 at Cape Canaveral Air Force Station in Florida, adjacent to NASA's Kennedy Space Center. Complex 14 served as the launch pad for Mercury astronaut John Glenn when he lifted off in 1962 to orbit the Earth, becoming the first American to do so. The astronaut class of 2013 was selected by NASA after an extensive year-and-a-half search. The new group will help the agency push the boundaries of exploration and travel to new destinations in the solar system. To learn more about the astronaut class of 2013, visit: http://www.nasa.gov/astronauts/2013astroclass.html Photo credit: NASA/Frankie Martin
Autonomous Navigation Error Propagation Assessment for Lunar Surface Mobility Applications
NASA Technical Reports Server (NTRS)
Welch, Bryan W.; Connolly, Joseph W.
2006-01-01
The NASA Vision for Space Exploration is focused on the return of astronauts to the Moon. While navigation systems have already been proven in the Apollo missions to the moon, the current exploration campaign will involve more extensive and extended missions requiring new concepts for lunar navigation. In this document, the results of an autonomous navigation error propagation assessment are provided. The analysis is intended to be the baseline error propagation analysis for which Earth-based and Lunar-based radiometric data are added to compare these different architecture schemes, and quantify the benefits of an integrated approach, in how they can handle lunar surface mobility applications when near the Lunar South pole or on the Lunar Farside.
2014-01-24
The Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite acquired this natural-color image of central China on January 23, 2013 at 04:05 UTC. The image shows extensive haze over the region. In areas where the ground is visible, some of the landscape is covered with lingering snow. Credit: NASA/GSFC/Jeff Schmaltz/MODIS Land Rapid Response Team 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
NASA Technical Reports Server (NTRS)
Sergeyevsky, A. B.; Snyder, G. C.
1981-01-01
Graphical data necessary for the preliminary design of ballistic missions to Saturn are provided. Contours of launch energy requirements as well as many other launch and Saturn arrival parameters, are presented in launch date/arrival date space for all launch opportunities from 1985 through 2005. In addition, an extensive text is included which explains mission design methods, from launch window development to Saturn probe and orbiter arrival design, utilizing the graphical data in this volume as well as numerous equations elating various parameters. This is the first of a planned series of mission design documents which will apply to all planets and some other bodies in the solar system.
Visualization Techniques in Space and Atmospheric Sciences
NASA Technical Reports Server (NTRS)
Szuszczewicz, E. P. (Editor); Bredekamp, Joseph H. (Editor)
1995-01-01
Unprecedented volumes of data will be generated by research programs that investigate the Earth as a system and the origin of the universe, which will in turn require analysis and interpretation that will lead to meaningful scientific insight. Providing a widely distributed research community with the ability to access, manipulate, analyze, and visualize these complex, multidimensional data sets depends on a wide range of computer science and technology topics. Data storage and compression, data base management, computational methods and algorithms, artificial intelligence, telecommunications, and high-resolution display are just a few of the topics addressed. A unifying theme throughout the papers with regards to advanced data handling and visualization is the need for interactivity, speed, user-friendliness, and extensibility.
NASA Technical Reports Server (NTRS)
Klumpar, D. M. (Principal Investigator)
1982-01-01
The feasibility of modeling magnetic fields due to certain electrical currents flowing in the Earth's ionosphere and magnetosphere was investigated. A method was devised to carry out forward modeling of the magnetic perturbations that arise from space currents. The procedure utilizes a linear current element representation of the distributed electrical currents. The finite thickness elements are combined into loops which are in turn combined into cells having their base in the ionosphere. In addition to the extensive field modeling, additional software was developed for the reduction and analysis of the MAGSAT data in terms of the external current effects. Direct comparisons between the models and the MAGSAT data are possible.
Biotelemetry and computer analysis of sleep processes on earth and in space.
NASA Technical Reports Server (NTRS)
Adey, W. R.
1972-01-01
Developments in biomedical engineering now permit study of states of sleep, wakefulness, and focused attention in man exposed to rigorous environments, including aerospace flight. These new sensing devices, data acquisition systems, and computational methods have also been extensively applied to clinical problems of disordered sleep. A 'library' of EEG data has been prepared for sleep in normal man, and characterized for its group features by computational analysis. Sleep in an astronaut in space flight has been examined for the first and second 'nights' of space flight. Normal 90-min cycles were detected during the second night. Sleep patterns in quadriplegic patients deprived of all sensory inputs below the neck have indicated major deviations.
Overview of lunar-based astronomy
NASA Technical Reports Server (NTRS)
Smith, Harlan J.
1988-01-01
The opportunities along with the advantages and disadvantages of the Moon for astronomical observatories are carefully and methodically considered. Taking a relatively unbiased approach, it was concluded that lunar observatories will clearly be a major factor in the future of astronomy in the next century. He concludes that ground based work will continue because of its accessibility and that Earth orbital work will remain useful, primarily for convenience of access in constructing and operating very large space systems. Deep space studies will feature not only probes but extensive systems for extremely long baseline studies at wavelengths from gamma rays through visible and IR out to radio is also a conclusion drawn, along with the consideration that lunar astronomy will have found important permanent applications along lines such as are discussed at the present symposium and others quite unsuspected today.
NASA Astrophysics Data System (ADS)
Gunn, Stanley V.
1998-01-01
The term, ``power beaming'', creates an image of a beam of focused electromagnetic radiation, possessing good transmission characteristics and sufficient intensity to effect the delivery of meaningful amounts of power to a designated receiver. High power, free-electron lasers are well suited for long range transmission of their laser beam to designated space receivers because their selective near infrared wave length can be adjusted to match the absorption characteristics of the receiver's photo voltaic cells. The typical system envisioned is comprised of a 200 kw free electron laser, possessing an over-all efficiency of 10%, and an optical beam director system equipped with appropriate tracking and atmospheric compensation capabilities. Such an installation located at four to five appropriate locations around the earth could provide remarkable benefits to the projected power demands for transfer and maneuvering into orbit and for operating future fleets of satellites.
The Quaternary and Pliocene Yellowstone Plateau volcanic field of Wyoming, Idaho, and Montana
Christiansen, Robert L.
2001-01-01
This region of Yellowstone National Park has been the active focus of one of the Earth's largest magmatic systems for more than 2 million years. The resulting volcanism has been characterized by the eruption of voluminous rhyolites and subordinate basalts but virtually no lavas of intermediate composition. The magmatic system at depth remains active and drives the massive hydrothermal circulation for which the park is widely known. Studies of the volcanic field using geologic mapping and petrology have defined three major cycles of rhyolitic volcanism, each climaxed by the eruption of a rhyolitic ash-flow sheet having a volume of hundreds of thousands of cubic kilometers. The field also has been analyzed in terms of its magmatic and tectonic evolution, including its regional relation to the Snake River plain and to basin-range tectonic extension.
Earth orbit navigation study. Volume 2: System evaluation
NASA Technical Reports Server (NTRS)
1972-01-01
An overall systems evaluation was made of five candidate navigation systems in support of earth orbit missions. The five systems were horizon sensor system, unkown landmark tracking system, ground transponder system, manned space flight network, and tracking and data relay satellite system. Two reference missions were chosen: a low earth orbit mission and a transfer trajectory mission from low earth orbit to geosynchronous orbit. The specific areas addressed in the evaluation were performance, multifunction utilization, system mechanization, and cost.
An Overview of the EOS Data Dissemination Systems
NASA Technical Reports Server (NTRS)
Ramapriyan, H.K.; Pfister, Robin; Weinstein, Beth
2008-01-01
The Earth Observing System Data and Information System (EOSDIS) is the primary data system serving the broad-scope of NASA s Earth Observing System (EOS) program and a significant portion of the "heritage" Earth science data. EOSDIS was designed to support the Earth sciences within NASA s Science Mission Directorate (previously the Earth Science Enterprise (ESE) and Mission to Planet Earth). The EOS Program was NASA s contribution to the United States Global Change Research Program (USGCRP) enacted by Congress in 1990 as part of the Global Change Act. ESE s objective was to launch a series of missions to help answer fundamental global change questions such as "How is Earth changing?" and "What are the consequences for life on Earth?" resulting support of this objective, EOSDIS distributes a wide variety of data to a diverse community.
NASA Astrophysics Data System (ADS)
Smallwood, Jeremy L.; Martin, Rebecca G.; Lepp, Stephen; Livio, Mario
2018-01-01
With N-body simulations of a planetary system with an asteroid belt, we investigate how the asteroid impact rate on the Earth is affected by the architecture of the planetary system. We find that the ν6 secular resonance plays an important role in the asteroid collision rate with the Earth. Compared to exoplanetary systems, the Solar system is somewhat special in its lack of a super-Earth mass planet in the inner Solar system. We therefore first consider the effects of the presence of a super-Earth in the terrestrial planet region. We find a significant effect for super-Earths with a mass of around 10 M⊕ and a separation greater than about 0.7 au. For a super-Earth which is interior to the Earth's orbit, the number of asteroids colliding with Earth increases the closer the super-Earth is to the Earth's orbit. This is the result of multiple secular resonance locations causing more asteroids to be perturbed on to Earth-crossing orbits. When the super-Earth is placed exterior to Earth's orbit, the collision rate decreases substantially because the ν6 resonance no longer exists in the asteroid belt region. We also find that changing the semimajor axis of Saturn leads to a significant decrease in the asteroid collision rate, though increasing its mass increases the collision rate. These results may have implications for the habitability of exoplanetary systems.
A Polarimetric Extension of the van Cittert-Zernike Theorem for Use with Microwave Interferometers
NASA Technical Reports Server (NTRS)
Piepmeier, J. R.; Simon, N. K.
2004-01-01
The van Cittert-Zernike theorem describes the Fourier-transform relationship between an extended source and its visibility function. Developments in classical optics texts use scalar field formulations for the theorem. Here, we develop a polarimetric extension to the van Cittert-Zernike theorem with applications to passive microwave Earth remote sensing. The development provides insight into the mechanics of two-dimensional interferometric imaging, particularly the effects of polarization basis differences between the scene and the observer.
Observed ices in the Solar System
Clark, Roger N.; Grundy, Will; Carlson, Robert R.; Noll, Keith; Gudipati, Murthy; Castillo-Rogez, Julie C.
2013-01-01
Ices have been detected and mapped on the Earth and all planets and/or their satellites further from the sun. Water ice is the most common frozen volatile observed and is also unambiguously detected or inferred in every planet and/or their moon(s) except Venus. Carbon dioxide is also extensively found in all systems beyond the Earth except Pluto although it sometimes appears to be trapped rather than as an ice on some objects. The largest deposits of carbon dioxide ice is on Mars. Sulfur dioxide ice is found in the Jupiter system. Nitrogen and methane ices are common beyond the Uranian system. Saturn’s moon Titan probably has the most complex active chemistry involving ices, with benzene (C6H6) and many tentative or inferred compounds including ices of Cyanoacetylene (HC3N), Toluene (C7H8), Cyanogen (C2N2), Acetonitrile (CH3CN), H2O, CO2, and NH3. Confirming compounds on Titan is hampered by its thick smoggy atmosphere. Ammonia was predicted on many icy moons but is notably absent among the definitively detected ices with the possible exception of Enceladus. Comets, storehouses of many compounds that could exist as ices in their nuclei, have only had small amounts of water ice definitively detected on their surfaces. Only one asteroid has had a direct detection of surface water ice, although its presence can be inferred in others. This chapter reviews some of the properties of ices that lead to their detection, and surveys the ices that have been observed on solid surfaces throughout the Solar System.
System cost/performance analysis (study 2.3). Volume 1: Executive summary
NASA Technical Reports Server (NTRS)
Kazangey, T.
1973-01-01
The relationships between performance, safety, cost, and schedule parameters were identified and quantified in support of an overall effort to generate program models and methodology that provide insight into a total space vehicle program. A specific space vehicle system, the attitude control system (ACS), was used, and a modeling methodology was selected that develops a consistent set of quantitative relationships among performance, safety, cost, and schedule, based on the characteristics of the components utilized in candidate mechanisms. These descriptive equations were developed for a three-axis, earth-pointing, mass expulsion ACS. A data base describing typical candidate ACS components was implemented, along with a computer program to perform sample calculations. This approach, implemented on a computer, is capable of determining the effect of a change in functional requirements to the ACS mechanization and the resulting cost and schedule. By a simple extension of this modeling methodology to the other systems in a space vehicle, a complete space vehicle model can be developed. Study results and recommendations are presented.
Planetary health: protecting human health on a rapidly changing planet.
Myers, Samuel S
2018-12-23
The impact of human activities on our planet's natural systems has been intensifying rapidly in the past several decades, leading to disruption and transformation of most natural systems. These disruptions in the atmosphere, oceans, and across the terrestrial land surface are not only driving species to extinction, they pose serious threats to human health and wellbeing. Characterising and addressing these threats requires a paradigm shift. In a lecture delivered to the Academy of Medical Sciences on Nov 13, 2017, I describe the scale of human impacts on natural systems and the extensive associated health effects across nearly every dimension of human health. I highlight several overarching themes that emerge from planetary health and suggest advances in the way we train, reward, promote, and fund the generation of health scientists who will be tasked with breaking out of their disciplinary silos to address this urgent constellation of health threats. I propose that protecting the health of future generations requires taking better care of Earth's natural systems. Copyright © 2017 Elsevier Ltd. All rights reserved.
Commercial Crew Development Environmental Control and Life Support System Status: 2011-2012
NASA Technical Reports Server (NTRS)
Williams, David E.
2011-01-01
The National Aeronautics and Space Administration (NASA) Commercial Crew Development (CCDev) - 2 Program is managed within the new Commercial Crew Program Office (CCPO) to help develop a commercial crew transportation system to low earth orbit (LEO). It is intended to foster entrepreneurial activities with a few selected companies. The entrepreneurial activities were encouraged with these few selected companies by NASA providing only part of the total funding to complete specific tasks that were jointly agreed to by NASA and the company. These joint agreements were documented in a Space Act Agreement (SAA) that was signed jointly by NASA and the selected company. This paper will provide an overview of the CCDev - 2 Program and also it will discuss in a high level the Active Thermal Control System (ATCS) / Environmental Control and Life Support (ECLS) System tasks that were performed under CCDev - 2 from the start of CCDev - 2 to March 2012. It will also discuss the extension of the CCDev - 2 Program being proposed for the near future. 1
Space Nuclear Thermal Propulsion Test Facilities Subpanel
NASA Technical Reports Server (NTRS)
Allen, George C.; Warren, John W.; Martinell, John; Clark, John S.; Perkins, David
1993-01-01
On 20 Jul. 1989, in commemoration of the 20th anniversary of the Apollo 11 lunar landing, President George Bush proclaimed his vision for manned space exploration. He stated, 'First for the coming decade, for the 1990's, Space Station Freedom, the next critical step in our space endeavors. And next, for the new century, back to the Moon. Back to the future. And this time, back to stay. And then, a journey into tomorrow, a journey to another planet, a manned mission to Mars.' On 2 Nov. 1989, the President approved a national space policy reaffirming the long range goal of the civil space program: to 'expand human presence and activity beyond Earth orbit into the solar system.' And on 11 May 1990, he specified the goal of landing Astronauts on Mars by 2019, the 50th anniversary of man's first steps on the Moon. To safely and ever permanently venture beyond near Earth environment as charged by the President, mankind must bring to bear extensive new technologies. These include heavy lift launch capability from Earth to low-Earth orbit, automated space rendezvous and docking of large masses, zero gravity countermeasures, and closed loop life support systems. One technology enhancing, and perhaps enabling, the piloted Mars missions is nuclear propulsion, with great benefits over chemical propulsion. Asserting the potential benefits of nuclear propulsion, NASA has sponsored workshops in Nuclear Electric Propulsion and Nuclear Thermal Propulsion and has initiated a tri-agency planning process to ensure that appropriate resources are engaged to meet this exciting technical challenge. At the core of this planning process, NASA, DOE, and DOD established six Nuclear Propulsion Technical Panels in 1991 to provide groundwork for a possible tri-agency Nuclear Propulsion Program and to address the President's vision by advocating an aggressive program in nuclear propulsion. To this end the Nuclear Electric Propulsion Technology Panel has focused it energies; this final report summarizes its endeavor and conclusions.
Planetary Defense: Options for Deflection of Near Earth Objects
NASA Technical Reports Server (NTRS)
Adams, R. B.; Statham, G.; Hopkins, R.; Chapman, J.; White, S.; Bonometti, J.; Alexander, R.; Fincher, S.; Polsgrove, T.; Kalkstein, M.
2003-01-01
Several recent near-miss encounters with asteroids and comets have focused attention on the threat of a catastrophic impact with the Earth. This document reviews the historical impact record and current understanding of the number and location of Near Earth Objects (NEO's) to address their impact probability. Various ongoing projects intended to survey and catalog the NEO population are also reviewed. Details are then given of an MSFC-led study, intended to develop and assess various candidate systems for protection of the Earth against NEOs. An existing program, used to model the NE0 threat, was extensively modified and is presented here. Details of various analytical tools, developed to evaluate the performance of proposed technologies for protection against the NEO threat, are also presented. Trajectory tools, developed to model the outbound path a vehicle would take to intercept or rendezvous with a target asteroid or comet, are described. Also, details are given of a tool that was created to model both the un-deflected inbound path of an NE0 as well as the modified, post-deflection, path. The number of possible options available for protection against the NE0 threat was too numerous for them to all be addressed within the study; instead, a representative selection were modeled and evaluated. The major output from this work was a novel process by which the relative effectiveness of different threat mitigation concepts can be evaluated during future, more detailed, studies. In addition, several new or modified mathematical models were developed to analyze various proposed protection systems. A summary of the major lessons learned during this study is presented, as are recommendations for future work. It is hoped that this study will serve to raise the level attention about this very real threat and also demonstrate that successful defense is both possible and practicable, provided appropriate steps are taken.
NASA Astrophysics Data System (ADS)
Stevens, T.; Olsen, L. M.; Ritz, S.; Morahan, M.; Aleman, A.; Cepero, L.; Gokey, C.; Holland, M.; Cordova, R.; Areu, S.; Cherry, T.; Tran-Ho, H.
2012-12-01
Discovering Earth science data can be complex if the catalog holding the data lacks structure. Controlled keyword vocabularies within metadata catalogues can improve data discovery. NASA's Global Change Master Directory's (GCMD) Keyword Management System (KMS) is a recently released a RESTful web service for managing and providing access to controlled keywords (science keywords, service keywords, platforms, instruments, providers, locations, projects, data resolution, etc.). The KMS introduces a completely new paradigm for the use and management of the keywords and allows access to these keywords as SKOS Concepts (RDF), OWL, standard XML, and CSV. A universally unique identifier (UUID) is automatically assigned to each keyword, which uniquely identifies each concept and its associated information. A component of the KMS is the keyword manager, an internal tool that allows GCMD science coordinators to manage concepts. This includes adding, modifying, and deleting broader, narrower, or related concepts and associated definitions. The controlled keyword vocabulary represents over 20 years of effort and collaboration with the Earth science community. The maintenance, stability, and ongoing vigilance in maintaining mutually exclusive and parallel keyword lists is important for a "normalized" search and discovery, and provides a unique advantage for the science community. Modifications and additions are made based on community suggestions and internal review. To help maintain keyword integrity, science keyword rules and procedures for modification of keywords were developed. This poster will highlight the use of the KMS as a beneficial service for the stewardship and access of the GCMD keywords. Users will learn how to access the KMS and utilize the keywords. Best practices for managing an extensive keyword hierarchy will also be discussed. Participants will learn the process for making keyword suggestions, which subsequently help in building a controlled keyword vocabulary to improve earth science data discovery and access.
New Developments and Geoscience Applications of Synchrotron Computed Microtomography (Invited)
NASA Astrophysics Data System (ADS)
Rivers, M. L.; Wang, Y.; Newville, M.; Sutton, S. R.; Yu, T.; Lanzirotti, A.
2013-12-01
Computed microtomography is the extension to micron spatial resolution of the CAT scanning technique developed for medical imaging. Synchrotron sources are ideal for the method, since they provide a monochromatic, parallel beam with high intensity. High energy storage rings such as the Advanced Photon Source at Argonne National Laboratory produce x-rays with high energy, high brilliance, and high coherence. All of these factors combine to produce an extremely powerful imaging tool for earth science research. Techniques that have been developed include: - Absorption and phase contrast computed tomography with spatial resolution below one micron. - Differential contrast computed tomography, imaging above and below the absorption edge of a particular element. - High-pressure tomography, imaging inside a pressure cell at pressures above 10GPa. - High speed radiography and tomography, with 100 microsecond temporal resolution. - Fluorescence tomography, imaging the 3-D distribution of elements present at ppm concentrations. - Radiographic strain measurements during deformation at high confining pressure, combined with precise x-ray diffraction measurements to determine stress. These techniques have been applied to important problems in earth and environmental sciences, including: - The 3-D distribution of aqueous and organic liquids in porous media, with applications in contaminated groundwater and petroleum recovery. - The kinetics of bubble formation in magma chambers, which control explosive volcanism. - Studies of the evolution of the early solar system from 3-D textures in meteorites - Accurate crystal size distributions in volcanic systems, important for understanding the evolution of magma chambers. - The equation-of-state of amorphous materials at high pressure using both direct measurements of volume as a function of pressure and also by measuring the change x-ray absorption coefficient as a function of pressure. - The location and chemical speciation of toxic elements such as arsenic and nickel in soils and in plant tissues in contaminated Superfund sites. - The strength of earth materials under the pressure and temperature conditions of the Earth's mantle, providing insights into plate tectonics and the generation of earthquakes.
NASA Astrophysics Data System (ADS)
Low, R.; Gosselin, D. C.; Oglesby, R. J.; Larson-Miller, C.; Thomas, J.; Mawalagedara, R.
2011-12-01
Over the past three years the Nebraska Earth Systems Education Network has designed professional development opportunities for K-12 and extension educators that integrates scientific content into the context of helping educators connect society with the complexities and consequences of climate change. Our professional development approach uses learner-, knowledge-, assessment-, and community-centered strategies to achieve our long-term goal: collaboration of scientists, educators and learners to foster civic literacy about climate change. Two NASA-funded projects, Global Climate Change Literacy for Educators (GCCE, 2009-2012), and the Educators Climatologists Learning Community (ECLC, 2011-2013), have provided the mechanism to provide teachers with scientifically sound and pedagogically relevant educational materials to improve climate and Earth systems literacy among educators. The primary product of the GCCE program is a 16-week, online, distance-delivered, asynchronous course entitled, Laboratory Earth: Human Dimensions of Climate Change. This course consists of four, four-week modules that integrate climate literacy, Earth Systems concepts, and pedagogy focused on active learning processes, building community, action research, and students' sense of place to promote action at the local level to address the challenges of climate change. Overall, the Community of Inquiry Survey (COI) indicated the course was effective in teaching content, developing a community of learners, and engaging students in experiences designed to develop content knowledge. A pre- and post- course Wilcoxan Signed Ranks Test indicated there was a statistically significant increase in participant's beliefs about their personal science teaching efficacy. Qualitative data from concept maps and content mastery assignments support a positive impact on teachers' content knowledge and classroom practice. Service Learning units seemed tohelp teachers connect course learning to their classroom teaching. In addition, qualitative data indicate that teachers' students found service learning to be highly motivational components to learning. The ECLC project, to be initiated in the fall 2011, will build on our GCCE experiences to create a sustainable virtual learning community of educators and scientists. Climate-change issues will serve as a context in which collaborative scientist-educator-teams will develop discrete, locally oriented research projects to facilitate development of confident, knowledgeable citizen-scientists within their classrooms.
Large-Scale and Global Hydrology. Chapter 92
NASA Technical Reports Server (NTRS)
Rodell, Matthew; Beaudoing, Hiroko Kato; Koster, Randal; Peters-Lidard, Christa D.; Famiglietti, James S.; Lakshmi, Venkat
2016-01-01
Powered by the sun, water moves continuously between and through Earths oceanic, atmospheric, and terrestrial reservoirs. It enables life, shapes Earths surface, and responds to and influences climate change. Scientists measure various features of the water cycle using a combination of ground, airborne, and space-based observations, and seek to characterize it at multiple scales with the aid of numerical models. Over time our understanding of the water cycle and ability to quantify it have improved, owing to advances in observational capabilities, the extension of the data record, and increases in computing power and storage. Here we present some of the most recent estimates of global and continental ocean basin scale water cycle stocks and fluxes and provide examples of modern numerical modeling systems and reanalyses.Further, we discuss prospects for predicting water cycle variability at seasonal and longer scales, which is complicated by a changing climate and direct human impacts related to water management and agriculture. Changes to the water cycle will be among the most obvious and important facets of climate change, thus it is crucial that we continue to invest in our ability to monitor it.
Martian paleolakes and waterways: Exobiological implications
Scott, D.H.; Rice, J. W.; Dohm, J.M.
1991-01-01
The problems of how warm and wet Mars once was and when climate transitions may have occurred are not well understood. Mars may have had an early environment similar to Earth's that was conductive to the ermergence of life. In addition, increasing geologic evidence indicates that water, upon which terrestrial life depends, has been present on Mars throughout its history. This evidence suggests that life could have developed not only on early Mars but also over longer periods of time in longer lasting, more clement local environments. Indications of past or present life most likely would be found in areas where liquid water existed in sufficient quantities to provide for the needs of biological systems. We suggest that paleolakes may have provided such environments. Unlike the case on Earth, this record of the origin and evolution of life has probably not been erased by extensive deformation of the Martian surface. Our work has identified eleven prospective areas where large lacustrine basins may once have existed. These areas are important for future biological, geological, and climatological investigations. ?? 1991 Kluwer Academic Publishers.
NASA Technical Reports Server (NTRS)
Consolmagno, G. J.; Drake, M. J.
1977-01-01
Quantitative modeling of the evolution of rare earth element (REE) abundances in the eucrites, which are plagioclase-pigeonite basalt achondrites, indicates that the main group of eucrites (e.g., Juvinas) might have been produced by approximately 10% equilibrium partial melting of a single type of source region with initial REE abundances which were chondritic relative and absolute. Since the age of the eucrites is about equal to that of the solar system, extensive chemical differentiation of the eucrite parent body prior to the formation of eucrites seems unlikely. If homogeneous accretion is assumed, the bulk composition of the eucrite parent body can be estimated; two estimates are provided, representing different hypotheses as to the ratio of metal to olivine in the parent body. Since a large number of differentiated olivine meteorites, which would represent material from the interior of the parent body, have not been detected, the eucrite parent body is thought to be intact. It is suggested that the asteroid 4 Vesta is the eucrite parent body.
Software for Displaying Data from Planetary Rovers
NASA Technical Reports Server (NTRS)
Powell, Mark; Backers, Paul; Norris, Jeffrey; Vona, Marsette; Steinke, Robert
2003-01-01
Science Activity Planner (SAP) DownlinkBrowser is a computer program that assists in the visualization of processed telemetric data [principally images, image cubes (that is, multispectral images), and spectra] that have been transmitted to Earth from exploratory robotic vehicles (rovers) on remote planets. It is undergoing adaptation to (1) the Field Integrated Design and Operations (FIDO) rover (a prototype Mars-exploration rover operated on Earth as a test bed) and (2) the Mars Exploration Rover (MER) mission. This program has evolved from its predecessor - the Web Interface for Telescience (WITS) software - and surpasses WITS in the processing, organization, and plotting of data. SAP DownlinkBrowser creates Extensible Markup Language (XML) files that organize data files, on the basis of content, into a sortable, searchable product database, without the overhead of a relational database. The data-display components of SAP DownlinkBrowser (descriptively named ImageView, 3DView, OrbitalView, PanoramaView, ImageCubeView, and SpectrumView) are designed to run in a memory footprint of at least 256MB on computers that utilize the Windows, Linux, and Solaris operating systems.
ESPAS: the European e-science platform to access near-Earth space data (Invited)
NASA Astrophysics Data System (ADS)
Belehaki, A.; Hapgood, M. A.; Ritschel, B.; Manola, N.
2013-12-01
The aim of ESPAS platform is to integrate heterogeneous data from the earth's thermosphere, ionosphere, plasmasphere and magnetosphere. ESPAS supports the systematic exploration of multipoint measurements from the near-Earth space through homogenised access to multi-instrument data. It provides access to more than 40 datasets: Cluster, EISCAT, GIRO, DIAS, SWACI, CHAMP, SuperDARN, FPI, magnetometers INGV, SGO, DTU, IMAGE, TGO, IMAGE/RPI, ACE, SOHO, PROBA2, NOAA/POES, etc. The concept of extensibility to new data sets is an important element in the ESPAS architecture. Within the first year of the project, the main components of the system have been developed, namely, the data model, the XML schemas for metadata exchange format, the ontology, the wrapper installed at the data nodes so that the main platform harvest the metadata, the main platform built on the D-NET framework and the GUI with its designed workflows. The first working prototype supports the search for datasets among a selected number of databases (i.e., EDAM, DIAS, Cluster, SWACI data). The next immediate step would be the implementation of search for characteristics within the datasets. For the second release we are planning to deploy tools for conjunctions between ground-space and space-space and for coincidences. For the final phase of the project the ESPAS infrastructure will be extensively tested through the application of several use cases, designed to serve the needs of the wide interdisciplinary users and producers communities, such as the ionospheric, thermospheric, magnetospheric, space weather and space climate communities, the geophysics community, the space communications engineering, HF users, satellite operators, navigation and surveillance systems, and space agencies. The final ESPAS platform is expected to be delivered in 2015. The abstract is submitted on behalf of the ESPAS-FP7EU team (http://www.espas-fp7.eu): Mike Hapgood, Anna Belehaki, Spiros Ventouras, Natalia Manola, Antonis Lebesis, Bruno Zolesi, Tatjana Gerzen, Ingemar Häggström, Anna Charisi, Ivan Galkin, Jurgen Watermann, Matthew Angling, Timo Asikainen, Alan Aylward, Henrike Barkmann, Peter Bergqvist, Andrew Bushell, Fabien Darrouzet, Dimitris Dialetis, Carl-Fredrik Enell, Daniel Heynderickx, Norbert Jakowski, Magnar Johnsen, Jean Lilensten, Ian McCrea, Kalevi Mursula, Bogdan Nicula, Michael Pezzopane, Viviane Pierrard, Bodo Reinisch, Bernd Ritschel, Luca Spogli, Iwona Stanislawska, Claudia Stolle, Eija Tanskanen, Ioanna Tsagouri, Esa Turunen, Thomas Ulich, Matthew Wild, Tim Yeoman
Land subsidence and earth fissures in south-central and southern Arizona, USA
NASA Astrophysics Data System (ADS)
Conway, Brian D.
2016-05-01
Land subsidence due to groundwater overdraft has been an ongoing problem in south-central and southern Arizona (USA) since the 1940s. The first earth fissure attributed to excessive groundwater withdrawal was discovered in the early 1950s near Picacho. In some areas of the state, groundwater-level declines of more than 150 m have resulted in extensive land subsidence and earth fissuring. Land subsidence in excess of 5.7 m has been documented in both western metropolitan Phoenix and Eloy. The Arizona Department of Water Resources (ADWR) has been monitoring land subsidence since 2002 using interferometric synthetic aperture radar (InSAR) and since 1998 using a global navigation satellite system (GNSS). The ADWR InSAR program has identified more than 25 individual land subsidence features that cover an area of more than 7,300 km2. Using InSAR data in conjunction with groundwater-level datasets, ADWR is able to monitor land subsidence areas as well as identify areas that may require additional monitoring. One area of particular concern is the Willcox groundwater basin in southeastern Arizona, which is the focus of this paper. The area is experiencing rapid groundwater declines, as much as 32.1 m during 2005-2014 (the largest land subsidence rate in Arizona State—up to 12 cm/year), and a large number of earth fissures. The declining groundwater levels in Arizona are a challenge for both future groundwater availability and mitigating land subsidence associated with these declines. ADWR's InSAR program will continue to be a critical tool for monitoring land subsidence due to excessive groundwater withdrawal.
Future Earth Coasts: The Mississippi and Yangtze Rivers as Examples
NASA Astrophysics Data System (ADS)
D'Elia, C.; Xu, K.; Chen, Z.; Day, J.; Le Tissier, M.
2016-02-01
Deltas and estuaries are productive and fertile links between the land and the sea. Deltas occupy only about 5% of the Earth's surface but sustain over a half billion people all around the world. Many river deltas are endangered because of extensive dam and levee construction, declining sediment supply, groundwater withdrawal, relative sea level rise and severe coastal erosion, leading to a variety of threats to natural, economic and social systems. About 630 million people now live at an elevation of 10 m or less above mean sea level, and maintaining sustainable land with a rising sea will be a challenging problem for many major deltaic coasts and cities in the next century. Stemming from 20 years of LOICZ (Land-Ocean Interactions in the Coastal Zone), Future Earth Coasts is a new global initiative that seeks to enable the scientific and social scientific communities to build knowledge through collaborative processes to better understand and address the profound and urgent changes occurring in vulnerable coastal zones. The topics of this comparative study are the Mississippi and Yangtze (Changjiang) Rivers, the largest in the United States and China, respectively. We use these two rivers as examples to evaluate current conditions and catalyze future discussion. The Mississippi and Yangtze both have had long-term observations of physical and biological processes that affect human activities, making it possible to quantify both natural and anthropogenic impacts. We also consider the limits to concept of sustainability for the Earth's biosphere and human civilization, and emphasize biophysical constraints and demographic challenges.
Kinesthetic perceptions of earth- and body-fixed axes.
Darling, W G; Hondzinski, J M
1999-06-01
The major purpose of this research was to determine whether kinesthetic/proprioceptive perceptions of the earth-fixed vertical axis are more accurate than perceptions of intrinsic axes. In one experiment, accuracy of alignment of the forearm to earth-fixed vertical and head- and trunk-longitudinal axes by seven blindfolded subjects was compared in four tasks: (1) Earth-Arm--arm (humerus) orientation was manipulated by the experimenter; subjects aligned the forearm parallel to the vertical axis, which was also aligned with the head and trunk longitudinal axis; (2) Head--head, trunk, and upper-limb orientations were manipulated by the experimenter, subjects aligned the forearm parallel to the longitudinal axis of the head using only elbow flexion/extension and shoulder internal/external rotation; (3) Trunk--same as (2), except that subjects aligned the forearm parallel to the trunk-longitudinal axis; (4) Earth--same as (2), except that subjects aligned the forearm parallel to the earth-fixed vertical. Head, trunk, and gravitational axes were never parallel in tasks 2, 3, and 4 so that subjects could not simultaneously match their forearm to all three axes. The results showed that the errors for alignment of the forearm with the earth-fixed vertical were lower than for the trunk- and head-longitudinal axes. Furthermore, errors in the Earth condition were less dependent on alterations of the head and trunk orientation than in the Head and Trunk conditions. These data strongly suggest that the earth-fixed vertical is used as one axis for the kinesthetic sensory coordinate system that specifies upper-limb orientation at the perceptual level. We also examined the effects of varying gravitational torques at the elbow and shoulder on the accuracy of forearm alignment to earth-fixed axes. Adding a 450 g load to the forearm to increase gravitational torques when the forearm is not vertical did not improve the accuracy of forearm alignment with the vertical. Furthermore, adding small, variably sized loads (between which the subjects could not distinguish at the perceptual level) to the forearm just proximal to the wrist produced similar errors in aligning the forearm with the vertical and horizontal. Forearm-positioning errors were not correlated with the size of the load, as would be expected if gravitational torques affected forearm-position sense. We conclude that gravitational torques exerted about the shoulder and elbow do not make significant contributions to sensing forearm-orientation relative to earth-fixed axes when the upper-limb segments are not constrained by external supports.
Theoretical study of the alkaline-earth metal superoxides BeO2 through SrO2
NASA Technical Reports Server (NTRS)
Bauschlicher, Charles W., Jr.; Partridge, Harry; Sodupe, Mariona; Langhoff, Stephen R.
1992-01-01
Three competing bonding mechanisms have been identified for the alkaline-earth metal superoxides: these result in a change in the optimal structure and ground state as the alkaline-earth metal becomes heavier. For example, BeO2 has a linear 3Sigma(-)g ground-state structure, whereas both CaO2 and SrO2 have C(2v)1A1 structures. For MgO2, the theoretical calculations are less definitive, as the 3A2 C(2v) structure is computed to lie only about 3 kcal/mol above the 3Sigma(-)g linear structure. The bond dissociation energies for the alkaline-earth metal superoxides have been computed using extensive Gaussian basis sets and treating electron correlation at the modified coupled-pair functional or coupled-cluster singles and doubles level with a perturbational estimate of the triple excitations.
Small Reactor Designs Suitable for Direct Nuclear Thermal Propulsion: Interim Report
DOE Office of Scientific and Technical Information (OSTI.GOV)
Bruce G. Schnitzler
Advancement of U.S. scientific, security, and economic interests requires high performance propulsion systems to support missions beyond low Earth orbit. A robust space exploration program will include robotic outer planet and crewed missions to a variety of destinations including the moon, near Earth objects, and eventually Mars. Past studies, in particular those in support of both the Strategic Defense Initiative (SDI) and the Space Exploration Initiative (SEI), have shown nuclear thermal propulsion systems provide superior performance for high mass high propulsive delta-V missions. In NASA's recent Mars Design Reference Architecture (DRA) 5.0 study, nuclear thermal propulsion (NTP) was again selectedmore » over chemical propulsion as the preferred in-space transportation system option for the human exploration of Mars because of its high thrust and high specific impulse ({approx}900 s) capability, increased tolerance to payload mass growth and architecture changes, and lower total initial mass in low Earth orbit. The recently announced national space policy2 supports the development and use of space nuclear power systems where such systems safely enable or significantly enhance space exploration or operational capabilities. An extensive nuclear thermal rocket technology development effort was conducted under the Rover/NERVA, GE-710 and ANL nuclear rocket programs (1955-1973). Both graphite and refractory metal alloy fuel types were pursued. The primary and significantly larger Rover/NERVA program focused on graphite type fuels. Research, development, and testing of high temperature graphite fuels was conducted. Reactors and engines employing these fuels were designed, built, and ground tested. The GE-710 and ANL programs focused on an alternative ceramic-metallic 'cermet' fuel type consisting of UO2 (or UN) fuel embedded in a refractory metal matrix such as tungsten. The General Electric program examined closed loop concepts for space or terrestrial applications as well as open loop systems for direct nuclear thermal propulsion. Although a number of fast spectrum reactor and engine designs suitable for direct nuclear thermal propulsion were proposed and designed, none were built. This report summarizes status results of evaluations of small nuclear reactor designs suitable for direct nuclear thermal propulsion.« less
Tube dynamics and low energy Earth-Moon transfers in the 4-body system
NASA Astrophysics Data System (ADS)
Onozaki, Kaori; Yoshimura, Hiroaki; Ross, Shane D.
2017-11-01
In this paper, we show a low energy Earth-Moon transfer in the context of the Sun-Earth-Moon-spacecraft 4-body system. We consider the 4-body system as the coupled system of the Sun-Earth-spacecraft 3-body system perturbed by the Moon (which we call the Moon-perturbed system) and the Earth-Moon-spacecraft 3-body system perturbed by the Sun (which we call the Sun-perturbed system). In both perturbed systems, analogs of the stable and unstable manifolds are computed numerically by using the notion of Lagrangian coherent structures, wherein the stable and unstable manifolds play the role of separating orbits into transit and non-transit orbits. We obtain a family of non-transit orbits departing from a low Earth orbit in the Moon-perturbed system, and a family of transit orbits arriving into a low lunar orbit in the Sun-perturbed system. Finally, we show that we can construct a low energy transfer from the Earth to the Moon by choosing appropriate trajectories from both families and patching these trajectories with a maneuver.
DCO-VIVO: A Collaborative Data Platform for the Deep Carbon Science Communities
NASA Astrophysics Data System (ADS)
Wang, H.; Chen, Y.; West, P.; Erickson, J. S.; Ma, X.; Fox, P. A.
2014-12-01
Deep Carbon Observatory (DCO) is a decade-long scientific endeavor to understand carbon in the complex deep Earth system. Thousands of DCO scientists from institutions across the globe are organized into communities representing four domains of exploration: Extreme Physics and Chemistry, Reservoirs and Fluxes, Deep Energy, and Deep Life. Cross-community and cross-disciplinary collaboration is one of the most distinctive features in DCO's flexible research framework. VIVO is an open-source Semantic Web platform that facilitates cross-institutional researcher and research discovery. it includes a number of standard ontologies that interconnect people, organizations, publications, activities, locations, and other entities of research interest to enable browsing, searching, visualizing, and generating Linked Open (research) Data. The DCO-VIVO solution expedites research collaboration between DCO scientists and communities. Based on DCO's specific requirements, the DCO Data Science team developed a series of extensions to the VIVO platform including extending the VIVO information model, extended query over the semantic information within VIVO, integration with other open source collaborative environments and data management systems, using single sign-on, assigning of unique Handles to DCO objects, and publication and dataset ingesting extensions using existing publication systems. We present here the iterative development of these requirements that are now in daily use by the DCO community of scientists for research reporting, information sharing, and resource discovery in support of research activities and program management.
Cenozoic motion between East and West Antarctica
Cande; Stock; Muller; Ishihara
2000-03-09
The West Antarctic rift system is the result of late Mesozoic and Cenozoic extension between East and West Antarctica, and represents one of the largest active continental rift systems on Earth. But the timing and magnitude of the plate motions leading to the development of this rift system remain poorly known, because of a lack of magnetic anomaly and fracture zone constraints on seafloor spreading. Here we report on magnetic data, gravity data and swath bathymetry collected in several areas of the south Tasman Sea and northern Ross Sea. These results enable us to calculate mid-Cenozoic rotation parameters for East and West Antarctica. These rotations show that there was roughly 180 km of separation in the western Ross Sea embayment in Eocene and Oligocene time. This episode of extension provides a tectonic setting for several significant Cenozoic tectonic events in the Ross Sea embayment including the uplift of the Transantarctic Mountains and the deposition of large thicknesses of Oligocene sediments. Inclusion of this East-West Antarctic motion in the plate circuit linking the Australia, Antarctic and Pacific plates removes a puzzling gap between the Lord Howe rise and Campbell plateau found in previous early Tertiary reconstructions of the New Zealand region. Determination of this East-West Antarctic motion also resolves a long standing controversy regarding the contribution of deformation in this region to the global plate circuit linking the Pacific to the rest of the world.
The Australian Computational Earth Systems Simulator
NASA Astrophysics Data System (ADS)
Mora, P.; Muhlhaus, H.; Lister, G.; Dyskin, A.; Place, D.; Appelbe, B.; Nimmervoll, N.; Abramson, D.
2001-12-01
Numerical simulation of the physics and dynamics of the entire earth system offers an outstanding opportunity for advancing earth system science and technology but represents a major challenge due to the range of scales and physical processes involved, as well as the magnitude of the software engineering effort required. However, new simulation and computer technologies are bringing this objective within reach. Under a special competitive national funding scheme to establish new Major National Research Facilities (MNRF), the Australian government together with a consortium of Universities and research institutions have funded construction of the Australian Computational Earth Systems Simulator (ACcESS). The Simulator or computational virtual earth will provide the research infrastructure to the Australian earth systems science community required for simulations of dynamical earth processes at scales ranging from microscopic to global. It will consist of thematic supercomputer infrastructure and an earth systems simulation software system. The Simulator models and software will be constructed over a five year period by a multi-disciplinary team of computational scientists, mathematicians, earth scientists, civil engineers and software engineers. The construction team will integrate numerical simulation models (3D discrete elements/lattice solid model, particle-in-cell large deformation finite-element method, stress reconstruction models, multi-scale continuum models etc) with geophysical, geological and tectonic models, through advanced software engineering and visualization technologies. When fully constructed, the Simulator aims to provide the software and hardware infrastructure needed to model solid earth phenomena including global scale dynamics and mineralisation processes, crustal scale processes including plate tectonics, mountain building, interacting fault system dynamics, and micro-scale processes that control the geological, physical and dynamic behaviour of earth systems. ACcESS represents a part of Australia's contribution to the APEC Cooperation for Earthquake Simulation (ACES) international initiative. Together with other national earth systems science initiatives including the Japanese Earth Simulator and US General Earthquake Model projects, ACcESS aims to provide a driver for scientific advancement and technological breakthroughs including: quantum leaps in understanding of earth evolution at global, crustal, regional and microscopic scales; new knowledge of the physics of crustal fault systems required to underpin the grand challenge of earthquake prediction; new understanding and predictive capabilities of geological processes such as tectonics and mineralisation.
Space Resource Utilization and Extending Human Presence Across the Solar System
NASA Technical Reports Server (NTRS)
Curreri, Peter A.
2005-01-01
The Presidents Vision for Exploration is not a single mission, but an open ended journey that seeks to answer "How can we live on other worlds?" Using space resources is the only known approach for affordable, sustained, flexible, and self sufficient, human occupation beyond Earth orbit. Earth is a large planet. A simple analysis using the rocket equation shows that if Earth were a bit larger, chemical propulsion as a mechanism to access space would become impractical. Thus, even with the most efficient chemical rocket launch capability, the cost of lifting massive payloads into space will remain very steep (currently about $l00k/lb to the Moon and greater than $500k/lb to Mars). Space resource utilization should begin with an aggressive broad based demonstration program as afforded by the precursor missions implementation of the President's Vision of Exploration. Ion engine upper stages, for example, were studied for over 30 years, but only implemented in design after the Deep Space 1 in space demonstration. These demonstrations should include: extraction of elements from lunar regolith, and Martian soil and atmosphere, demonstration of power break even and growth from lunar or Mars moons derived photovoltaics, oxygen extraction for life support and propellant, and metals and alloys for in space repair and the production of habits and radiation shielding. Space resource utilization yields operational dividends through the subsequent programs including: propellant from lunar oxygen which could cut transportation costs from Earth in half, mega watts per year of power grown from lunar photovoltaics at decreasing cost per kW, decreased cost for human Mars missions by a factor of 10 by using propellant derived from Mars atmosphere for return, and in space manufacturing and food production with space resources yielding safe sustained and eventually self sufficient human presence in space. After the demonstration and implementation, the space resource utilization investment enables commercial and private viability beyond Earth orbit. For example, analysis has shown the lunar oxygen production for propellant becomes commercially viable after the exploration program completes the R&D, and power from lunar derived photovoltaics could, according to past NASA sponsored studies, pay for themselves while supplying most of Earth's electrical energy after about 17 years. Besides the Moon and Mars the resources of the near Earth asteroids enable the building of large space structures and science payloads. Analysis has shown that one of the thousands of these objects (some as easily accessible in space as the Moon and Mars), 2 km dia, the size of a typical open pit mine, would cost the total global financial product of Earth for 30,000 years if we were to launch it from Earth. Beyond Mars, the belt asteroids have been calculated to contain enough materials for habitat and life to support 10 quadrillion people. Thus, the development and use of space resources enables the extension of human life through the solar system allowing humanity to move from a planetary to a solar system society.
The Archean geology of the Godthabsfjord Region, southern west Greenland (includes excursion guide)
NASA Technical Reports Server (NTRS)
Mcgregor, V. R.; Nutman, A. P.; Friend, C. R. L.
1986-01-01
The part of the West Greenland Archean gneiss complex centered around Godthabsfjord and extending from Isukasia in the north to south Faeringehavn is studied. Extensive outcrops of 3800 to 3400 Ma rocks can provide some direct evidence of conditions and processes that operated on the Earth in the early Archean. However, the ways in which primary characteristics have been modified by later deformation, metamorphism, and chemical changes are first taken into account. The rocks exposed are the products of two major phases of accretion of continental crust, at 3800 to 3700 Ma and 3100 to 29 Ma. The main features of these two accretion phases are similar, but careful study of the least modified rocks may reveal differences related to changes in the Earth in the intervening period. The combination of excellent exposure over an extensive area, relatively detailed geological mapping of much of the region, and a considerable volume of isotopic and other geochemical data gives special insights into processes that operated at moderately deep levels of the crust in the Archean. Of particular interest is the effect of late Archean granulite facies metamorphism on early Archean rocks, especially the extent to which isotope systems were disturbed. Similar processes may well have partly or wholly destroyed evidence of more ancient components of other high grade terrains. This account does not attempt to be an exhaustive review of all work carried out on the geology of the region. Rather, it attempts to summarize aspects of the geology and some interest in the context of early crustal genesis.
Recent Advances in Geospatial Visualization with the New Google Earth
NASA Astrophysics Data System (ADS)
Anderson, J. C.; Poyart, E.; Yan, S.; Sargent, R.
2017-12-01
Google Earth's detailed, world-wide imagery and terrain data provide a rich backdrop for geospatial visualization at multiple scales, from global to local. The Keyhole Markup Language (KML) is an open standard that has been the primary way for users to author and share data visualizations in Google Earth. Despite its ease of use and flexibility for relatively small amounts of data, users can quickly run into difficulties and limitations working with large-scale or time-varying datasets using KML in Google Earth. Recognizing these challenges, we present our recent work toward extending Google Earth to be a more powerful data visualization platform. We describe a new KML extension to simplify the display of multi-resolution map tile pyramids - which can be created by analysis platforms like Google Earth Engine, or by a variety of other map tile production pipelines. We also describe how this implementation can pave the way to creating novel data visualizations by leveraging custom graphics shaders. Finally, we present our investigations into native support in Google Earth for data storage and transport formats that are well-suited for big raster and vector data visualization. Taken together, these capabilities make it easier to create and share new scientific data visualization experiences using Google Earth, and simplify the integration of Google Earth with existing map data products, services, and analysis pipelines.
Physics of windblown particles
NASA Technical Reports Server (NTRS)
Greeley, Ronald; Leach, Rodman; Marshall, John R.; White, Bruce; Iversen, James D.; Nickling, William G.; Gillette, Dale; Sorensen, Michael
1987-01-01
A laboratory facility proposed for the Space Station to investigate fundamental aspects of windblown particles is described. The experiments would take advantage of the environment afforded in earth orbit and would be an extension of research currently being conducted on the geology and physics of windblown sediments on earth, Mars, and Venus. Aeolian (wind) processes are reviewed in the planetary context, the scientific rational is given for specific experiments to be conducted, the experiment apparatus (the Carousel Wind Tunnel, or CWT) is described, and a plan presented for implementing the proposed research program.
ERIC Educational Resources Information Center
Scherer, Hannah H.; Holder, Lauren; Herbert, Bruce
2017-01-01
Engaging students in authentic problem solving concerning environmental issues in near-surface complex Earth systems involves both developing student conceptualization of Earth as a system and applying that scientific knowledge using techniques that model those used by professionals. In this first paper of a two-part series, we review the state of…
Building A Cloud Based Distributed Active Data Archive Center
NASA Technical Reports Server (NTRS)
Ramachandran, Rahul; Baynes, Katie; Murphy, Kevin
2017-01-01
NASA's Earth Science Data System (ESDS) Program facilitates the implementation of NASA's Earth Science strategic plan, which is committed to the full and open sharing of Earth science data obtained from NASA instruments to all users. The Earth Science Data information System (ESDIS) project manages the Earth Observing System Data and Information System (EOSDIS). Data within EOSDIS are held at Distributed Active Archive Centers (DAACs). One of the key responsibilities of the ESDS Program is to continuously evolve the entire data and information system to maximize returns on the collected NASA data.
Earth observing system. Data and information system. Volume 2A: Report of the EOS Data Panel
NASA Technical Reports Server (NTRS)
1986-01-01
The purpose of this report is to provide NASA with a rationale and recommendations for planning, implementing, and operating an Earth Observing System data and information system that can evolve to meet the Earth Observing System's needs in the 1990s. The Earth Observing System (Eos), defined by the Eos Science and Mission Requirements Working Group, consists of a suite of instruments in low Earth orbit acquiring measurements of the Earth's atmosphere, surface, and interior; an information system to support scientific research; and a vigorous program of scientific research, stressing study of global-scale processes that shape and influence the Earth as a system. The Eos data and information system is conceived as a complete research information system that would transcend the traditional mission data system, and include additional capabilties such as maintaining long-term, time-series data bases and providing access by Eos researchers to relevant non-Eos data. The Working Group recommends that the Eos data and information system be initiated now, with existing data, and that the system evolve into one that can meet the intensive research and data needs that will exist when Eos spacecraft are returning data in the 1990s.
Zircons reveal magma fluxes in the Earth's crust.
Caricchi, Luca; Simpson, Guy; Schaltegger, Urs
2014-07-24
Magma fluxes regulate the planetary thermal budget, the growth of continents and the frequency and magnitude of volcanic eruptions, and play a part in the genesis and size of magmatic ore deposits. However, because a large fraction of the magma produced on the Earth does not erupt at the surface, determinations of magma fluxes are rare and this compromises our ability to establish a link between global heat transfer and large-scale geological processes. Here we show that age distributions of zircons, a mineral often present in crustal magmatic rocks, in combination with thermal modelling, provide an accurate means of retrieving magma fluxes. The characteristics of zircon age populations vary significantly and systematically as a function of the flux and total volume of magma accumulated in the Earth's crust. Our approach produces results that are consistent with independent determinations of magma fluxes and volumes of magmatic systems. Analysis of existing age population data sets using our method suggests that porphyry-type deposits, plutons and large eruptions each require magma input over different timescales at different characteristic average fluxes. We anticipate that more extensive and complete magma flux data sets will serve to clarify the control that the global heat flux exerts on the frequency of geological events such as volcanic eruptions, and to determine the main factors controlling the distribution of resources on our planet.
Evolution of Indarch (EH4 Chondrite) at 1 GPa and High Temperature
NASA Technical Reports Server (NTRS)
Berthet, S.; Malavergne, V.; Righter, K.
2008-01-01
The chondritic meteorites are materials that are as old as the solar system itself characterized by variations in bulk chemical and oxidation state, and have long been considered possible building blocks that accreted to form the terrestrial inner planets. Enstatite chondrites contain nearly FeO free enstatite, silicon-rich kamacite and various sulfides indicating formation under highly reducing conditions. These materials could have participated in the formation of the Earth. However, "fingerprinting" of meteoritic materials has shown that no known meteoritic class corresponds to a hypothetical bulk Earth composition in every aspect. To derive constraints on early accretion and differentiation processes and possibly resolve the debate on the formation of the Earth, it is required to study experimentally a variety of chondritic materials and investigate their melting relations and elemental partitioning behavior at variable pressure (P), temperature (T) and oxygen fugacities (fO2). Variations in fO2 can indeed change chemical features and phase equilibria dramatically. The P-T phase diagrams of peridotites and carbonaceous chondrites have been extensively studied experimentally up to pressures and temperatures corresponding to the transition zone and lower mantle. Even though partial melting experiments have been conducted at ambient pressure on the enstatite chondrite Indarch, enstatite meteorites have never been experimentally investigated at high PT. The following investigation focuses on the effect of the fO2 on the phase relations of Indarch, an EH4 chondrite.
NASA Astrophysics Data System (ADS)
Zhang, H.; Thurber, C.; Wang, W.; Roecker, S. W.
2008-12-01
We extended our recent development of double-difference seismic tomography [Zhang and Thurber, BSSA, 2003] to the use of station-pair residual differences in addition to event-pair residual differences. Tomography using station- pair residual differences is somewhat akin to teleseismic tomography but with the sources contained within the model region. Synthetic tests show that the inversion using both event- and station-pair residual differences has advantages in terms of more accurately recovering higher-resolution structure in both the source and receiver regions. We used the Spherical-Earth Finite-Difference (SEFD) travel time calculation method in the tomographic system. The basic concept is the extension of a standard Cartesian FD travel time algorithm [Vidale, 1990] to the spherical case by developing a mesh in radius, co-latitude, and longitude, expressing the FD derivatives in a form appropriate to the spherical mesh, and constructing"stencil" to calculate extrapolated travel times. The SEFD travel time calculation method is more advantageous in dealing with heterogeneity and sphericity of the Earth than the simple Earth flattening transformation and the"sphere-in-a-bo" approach [Flanagan et al., 2007]. We applied this method to the Sichuan, China data set for the period of 2001 to 2004. The Vp, Vs and Vp/Vs models show that there is a clear contrast across the Longmenshan Fault, where the 2008 M8 Wenchuan earthquake initiated.
NASA Technical Reports Server (NTRS)
King, M. D. (Editor); Greenstone, R. (Editor)
2000-01-01
The content of this handbook includes Earth Science Enterprise; The Earth Observing System; EOS Data and Information System (EOSDIS); Data and Information Policy; Pathfinder Data Sets; Earth Science Information Partners and the Working Prototype-Federation; EOS Data Quality: Calibration and Validation; Education Programs; International Cooperation; Interagency Coordination; Mission Elements; EOS Instruments; EOS Interdisciplinary Science Investigations; and Points-of-Contact.
Integrated human-earth system modeling—state of the science and future directions
NASA Astrophysics Data System (ADS)
Calvin, Katherine; Bond-Lamberty, Ben
2018-06-01
Research on humans and the Earth system has historically occurred separately, with different teams and models devoted to each. Increasingly, however, these communities and models are becoming intricately linked. In this review, we survey the literature on integrated human-Earth system models, quantify the direction and strength of feedbacks in those models, and put them in context of other, more frequently considered, feedbacks in the Earth system. We find that such feedbacks have the potential to alter both human and Earth systems; however, there is significant uncertainty in these results, and the number of truly integrated studies remains small. More research, more models, and more studies are needed to robustly quantify the sign and magnitude of human-Earth system feedbacks. Integrating human and earth models entails significant complexity and cost, and researchers should carefully assess the costs and benefits of doing so with respect to the object of study.
NASA Technical Reports Server (NTRS)
Freeman, Anthony; Way, Jo Bea; Dubois, Pascale; Leberl, Franz
1993-01-01
We seek to combine high-resolution remotely sensed data with models and ground truth measurements, in the context of a Geographical Information System (GIS), integrated with specialized image processing software. We will use this integrated system to analyze the data from two Case Studies, one at a boreal forest site, the other a tropical forest site. We will assess the information content of the different components of the data, determine the optimum data combinations to study biogeophysical changes in the forest, assess the best way to visualize the results, and validate the models for the forest response to different radar wavelengths/polarizations. During the 1990's, unprecedented amounts of high-resolution images from space of the Earth's surface will become available to the applications scientist from the LANDSAT/TM series, European and Japanese ERS-1 satellites, RADARSAT and SIR-C missions. When the Earth Observation Systems (EOS) program is operational, the amount of data available for a particular site can only increase. The interdisciplinary scientist, seeking to use data from various sensors to study his site of interest, may be faced with massive difficulties in manipulating such large data sets, assessing their information content, determining the optimum combinations of data to study a particular parameter, visualizing his results and validating his model of the surface. The techniques to deal with these problems are also needed to support the analysis of data from NASA's current program of Multi-sensor Airborne Campaigns, which will also generate large volumes of data. In the Case Studies outlined in this proposal, we will have somewhat unique data sets. For the Bonanza Creek Experimental Forest (Case 1) calibrated DC-8 SAR (Synthetic Aperture Radar) data and extensive ground truth measurement are already at our disposal. The data set shows documented evidence to temporal change. The Belize Forest Experiment (Case 2) will produce calibrated DC-8 SAR and AVIRIS data, together with extensive measurements on the tropical rain forest itself. The extreme range of these sites, one an Arctic forest, the other a tropical rain forest, has been deliberately chosen to find common problems which can lead to generalized observations and unique problems with data which raise issues for the EOS System.
NASA Technical Reports Server (NTRS)
Freeman, Anthony; Way, Jo Bea; Dubois, Pascale; Leberl, Franz
1992-01-01
We seek to combine high-resolution remotely sensed data with models and ground truth measurements, in the context of a Geographical Information System, integrated with specialized image processing software. We will use this integrated system to analyze the data from two Case Studies, one at a bore Al forest site, the other a tropical forest site. We will assess the information content of the different components of the data, determine the optimum data combinations to study biogeophysical changes in the forest, assess the best way to visualize the results, and validate the models for the forest response to different radar wavelengths/polarizations. During the 1990's, unprecedented amounts of high-resolution images from space of the Earth's surface will become available to the applications scientist from the LANDSAT/TM series, European and Japanese ERS-1 satellites, RADARSAT and SIR-C missions. When the Earth Observation Systems (EOS) program is operational, the amount of data available for a particular site can only increase. The interdisciplinary scientist, seeking to use data from various sensors to study his site of interest, may be faced with massive difficulties in manipulating such large data sets, assessing their information content, determining the optimum combinations of data to study a particular parameter, visualizing his results and validating his model of the surface. The techniques to deal with these problems are also needed to support the analysis of data from NASA's current program of Multi-sensor Airborne Campaigns, which will also generate large volumes of data. In the Case Studies outlined in this proposal, we will have somewhat unique data sets. For the Bonanza Creek Experimental Forest (Case I) calibrated DC-8 SAR data and extensive ground truth measurement are already at our disposal. The data set shows documented evidence to temporal change. The Belize Forest Experiment (Case II) will produce calibrated DC-8 SAR and AVIRIS data, together with extensive measurements on the tropical rain forest itself. The extreme range of these sites, one an Arctic forest, the other a tropical rain forest, has been deliberately chosen to find common problems which can lead to generalized observations and unique problems with data which raise issues for the EOS System.
NASA Astrophysics Data System (ADS)
Saito, A.; Akiya, Y.; Yoshida, D.; Odagi, Y.; Yoshikawa, M.; Tsugawa, T.; Takahashi, M.; Kumano, Y.; Iwasaki, S.
2010-12-01
We have developed a four-dimensional display system of the Earth and planets to use in schools, science centers, and research institutes. It can display the Earth and planets in three-dimensional way without glasses, and the time variation of the scientific data can be displayed on the Earth and planets image. The system is named Dagik Earth, and educational programs using Dagik Earth have been developed for schools and science centers. Three dimensional displays can show the Earth and planets in exact form without any distortion, which cannot be achieved with two-dimensional display. Furthermore it can provide a sense of reality. There are several systems for the three-dimensional presentation of the Earth, such as Science on a sphere by NOAA, and Geocosmos by Miraikan, Japan. Comparing these systems, the advantage of Dagik Earth is portability and affordability. The system uses ordinary PC and PC projector. Only a spherical screen is the special equipment of Dagik Earth. Therefore Dagik Earth is easy to use in classrooms. Several educational programs have been developed and carried out in high schools, junior high schools, elementary schools and science centers. Several research institutes have used Dagik Earth in their public outreach programs to demonstrate their novel scientific results to public in an attractive way of presentation. A community of users and developers of Dagik Earth is being formed in Japan. In the presentation, the outline of Dagik Earth and the educational programs using Dagik Earth will be presented. Its future plan will also be discussed.
Kepler Confirms First Earth-Sized Planet Outside Our Solar System (Kepler-20) (Reporter Package)
2011-12-19
NASA's Kepler mission has confirmed the discovery of the first Earth-size planets outside our solar system orbiting a sun-like star. Located about 1,000 light years from Earth, the Kepler-20 solar system has five planets orbiting a star similar to the Sun. Kepler-20f, the 4th planet in the system, is about 90 percent the size of Earth. Kepler-20f is slightly larger than Earth,with a radius that is 3 percent larger.
Effect of Hydraulic Accumulator on Pressure Surge of a Hydrostatic Transmission System
NASA Astrophysics Data System (ADS)
Kumar, Ajit; Das, Jayanta; Dasgupta, Kabir; Barnwal, Manish Kumar
2018-04-01
Hydraulic power system is generally used in off-road vehicles for power transmission such as Heavy Earth Moving Machineries (HEMM). Their energy efficiency and unsubstantial failure becomes an extensive subject of analysis. Various arrangements in the system are compassed along with the utilization of some appropriate components. Application of a hydraulic accumulator is one among them. Benefits of accumulator is its multi-purpose usages like energy saving and pressure surge damping. This paper deals with the control of pressure surges in the hydraulic system and energy saving from the surges by using accumulator. For this purpose, the simulation of the hydraulic system is done in MATLAB/SimulinkR environment and an external disturbance is introduced to generate the pressure surge. The surge absorptivity of the accumulator is studied for different sizes at different pre-charged conditions of the accumulator. The discharge characteristics of different sized accumulators are also analyzed in this paper. It is observed that the ability to absorb the surge and stabilize the system is high in the smaller capacity accumulator. However the energy delivery time of larger sized accumulator is high.
NASA Technical Reports Server (NTRS)
Herman, Daniel A.; Tofil, Todd; Santiago, Walter; Kamhawi, Hani; Polk, James E.; Snyder, John Steven; Hofer, Richard R.; Picha, Frank; Jackson, Jerry; Allen, May
2017-01-01
NASA remains committed to the development and demonstration of a high-power solar electric propulsion capability for the Agency. NASA is continuing to develop the 14 kilowatt Advanced Electric Propulsion System (AEPS), which has recently completed an Early Integrated System Test and System Preliminary Design Review. NASA continues to pursue Solar Electric Propulsion (SEP) Technology Demonstration Mission partners and mature high-power SEP mission concepts. The recent announcement of the development of a Power and Propulsion Element (PPE) as the first element of an evolvable human architecture to Mars has replaced the Asteroid Redirect Robotic Mission as the most probable first application of the AEPS Hall thruster system. This high-power SEP capability, or an extensible derivative of it, has been identified as a critical part of an affordable, beyond-low-Earth-orbit, manned-exploration architecture. This paper presents the status of the combined NASA and Aerojet AEPS development activities and updated mission concept for implementation of the AEPS hardware as part of the ion propulsion system for a PPE.
Overview of the Development of the Advanced Electric Propulsion System (AEPS)
NASA Technical Reports Server (NTRS)
Herman, Daniel; Tofil, Todd; Santiago, Walter; Kamhawi, Hani; Polk, James; Snyder, John Steven; Hofer, Richard; Picha, Frank; Schmidt, George
2017-01-01
NASA is committed to the demonstration and application of high-power solar electric propulsion to meet its future mission needs. It is continuing to develop the 14 kW Advanced Electric Propulsion System (AEPS) under a project that recently completed an Early Integrated System Test (EIST) and System Preliminary Design Review (PDR). In addition, NASA is pursuing external partnerships in order to demonstrate Solar Electric Propulsion (SEP) technology and the advantages of high-power electric propulsion-based spacecraft. The recent announcement of a Power and Propulsion Element (PPE) as the first major piece of an evolvable human architecture to Mars has replaced the Asteroid Redirect Robotic Mission (ARRM) as the most likely first application of the AEPS Hall thruster system. This high-power SEP capability, or an extensible derivative of it, has been recognized as a critical part of a new, affordable human exploration architecture for missions beyond-low-Earth-orbit. This paper presents the status of AEPS development activities, and describes how AEPS hardware will be integrated into the PPE ion propulsion system.
NASA Technical Reports Server (NTRS)
Herman, Daniel A.; Tofil, Todd A.; Santiago, Walter; Kamhawi, Hani; Polk, James E.; Snyder, John S.; Hofer, Richard R.; Picha, Frank Q.; Jackson, Jerry; Allen, May
2018-01-01
NASA remains committed to the development and demonstration of a high-power solar electric propulsion capability for the Agency. NASA is continuing to develop the 14 kW Advanced Electric Propulsion System (AEPS), which has recently completed an Early Integrated System Test and System Preliminary Design Review. NASA continues to pursue Solar Electric Propulsion (SEP) Technology Demonstration Mission partners and mature high-power SEP mission concepts. The recent announcement of the development of a Power and Propulsion Element (PPE) as the first element of an evolvable human architecture to Mars has replaced the Asteroid Redirect Robotic Mission (ARRM) as the most probable first application of the AEPS Hall thruster system. This high-power SEP capability, or an extensible derivative of it, has been identified as a critical part of an affordable, beyond-low-Earth-orbit, manned exploration architecture. This paper presents the status of the combined NASA and Aerojet Rocketdyne AEPS development activities and updated mission concept for implementation of the AEPS hardware as part of the ion propulsion system for a PPE.
NASA Astrophysics Data System (ADS)
Cooper, John F.; Kauristie, K.; Weatherwax, A. T.; Sheehan, G. W.; Smith, R. W.; Sandahl, I.; Østgaard, N.; Chernouss, S.; Moore, M. H.; Peticolas, L. M.; Senske, D. A.; Thompson, B. J.; Tamppari, L. K.; Lewis, E. M.
2008-09-01
Polar, heliophysical, and planetary science topics related to the International Heliophysical and Polar Years 2007-2009 were addressed during this circumpolar video conference hosted January 23-29, 2008 at the new Barrow Arctic Research Center of the Barrow Arctic Science Consortium in Barrow, Alaska. This conference was planned as an IHY-IPY event science outreach event bringing together scientists and educational specialists for the first week of sunrise at subzero Arctic temperatures in Barrow. Science presentations spanned the solar system from the polar Sun to Earth, Moon, Mars, Jupiter, Saturn, and the Kuiper Belt. On-site participants experienced look and feel of icy worlds like Europa and Titan by being in the Barrow tundra and sea ice environment and by going "on the ice" during snowmobile expeditions to the near-shore sea ice environment and to Point Barrow, closest geographic point in the U.S. to the North Pole. Many science presentations were made remotely via video conference or teleconference from Sweden, Norway, Russia, Canada, Antarctica, and the United States, spanning up to thirteen time zones (Alaska to Russia) at various times. Extensive educational outreach activities were conducted with the local Barrow and Alaska North Slope communities and through the NASA Digital Learning Network live from the "top of the world" at Barrow. The Sun-Earth Day team from Goddard, and a videographer from the Passport to Knowledge project, carried out extensive educational interviews with many participants and native Inupiaq Eskimo residents of Barrow. Video and podcast recordings of selected interviews are available at http://sunearthday.nasa.gov/2008/multimedia/podcasts.php. Excerpts from these and other interviews will be included in a new high definition video documentary called "From the Sun to the Stars: The New Science of Heliophysics" from Passport to Knowledge that will later broadcast on NASA TV and other educational networks. Full conference proceedings are accessible at http://polargateways2008.org/.
Practices to enable the geophysical research spectrum: from fundamentals to applications
NASA Astrophysics Data System (ADS)
Kang, S.; Cockett, R.; Heagy, L. J.; Oldenburg, D.
2016-12-01
In a geophysical survey, a source injects energy into the earth and a response is measured. These physical systems are governed by partial differential equations and their numerical solutions are obtained by discretizing the earth. Geophysical simulations and inversions are tools for understanding physical responses and constructing models of the subsurface given a finite amount of data. SimPEG (http://simpeg.xyz) is our effort to synthesize geophysical forward and inverse methodologies into a consistent framework. The primary focus of our initial development has been on the electromagnetics (EM) package, with recent extensions to magnetotelluric, direct current (DC), and induced polarization. Across these methods, and applied geophysics in general, we require tools to explore and build an understanding of the physics (behaviour of fields, fluxes), and work with data to produce models through reproducible inversions. If we consider DC or EM experiments, with the aim of understanding responses from subsurface conductors, we require resources that provide multiple "entry points" into the geophysical problem. To understand the physical responses and measured data, we must simulate the physical system and visualize electric fields, currents, and charges. Performing an inversion requires that many moving pieces be brought together: simulation, physics, linear algebra, data processing, optimization, etc. Each component must be trusted, accessible to interrogation and manipulation, and readily combined in order to enable investigation into inversion methodologies. To support such research, we not only require "entry points" into the software, but also extensibility to new situations. In our development of SimPEG, we have sought to use leading practices in software development with the aim of supporting and promoting collaborations across a spectrum of geophysical research: from fundamentals to applications. Designing software to enable this spectrum puts unique constraints on both the architecture of the codebase as well as the development practices that are employed. In this presentation, we will share some lessons learned and, in particular, how our prioritization of testing, documentation, and refactoring has impacted our own research and fostered collaborations.
GDAL Enhancements for Interoperability with EOS Data (GEE)
NASA Astrophysics Data System (ADS)
Tisdale, B.
2015-12-01
Historically, Earth Observing Satellite (EOS) data products have been difficult to consume by GIS tools, weather commercial or open-source. This has resulted in a reduced acceptance of these data products by GIS and general user communities. Common problems and challenges experienced by these data users include difficulty when: Consuming data products from NASA Distributed Active Archive Centers (DAACs) that pre-date modern application software with commercial and open-source geospatial tools; Identifying[MI1] an initial approach for developing a framework and plug-ins that interpret non-compliant data; Defining a methodology that is extensible across NASA Earth Observing System Data and Information System (EOSDIS), scientific communities, and GIS communities by enabling other data centers to construct their own plug-ins and adjust specific data products; and Promoting greater use of NASA Data and new analysis utilizing GIS tools. To address these challenges and make EOS data products more accessible and interpretable by GIS applications, a collaborative approach has been taken that includes the NASA Langley Atmospheric Science Data Center (ASDC), Esri, George Mason University (GMU), and the Hierarchical Data Format (HDF) Group to create a framework and plugins to be applied to Geospatial Data Abstraction Library (GDAL). This framework and its plugins offer advantages of extensibility within NASA EOSDIS, permitting other data centers to construct their own plugins necessary to adjust their data products. In this session findings related to the framework and the development of GDAL plugins will be reviewed. Specifically, this session will offer a workshop to review documentation and training materials that have been generated for the purpose of guiding other NASA DAACs through the process of constructing plug-ins consistent with the framework as well as a review of the certification process by which the plugins can be independently verified as properly converting the data to the format and content required for use in GIS software.
GDAL Enhancements for Interoperability with EOS Data
NASA Astrophysics Data System (ADS)
Tisdale, M.; Mathews, T. J.; Tisdale, B.; Sun, M.; Yang, C. P.; Lee, H.; Habermann, T.
2015-12-01
Historically, Earth Observing Satellite (EOS) data products have been difficult to consume by GIS tools, weather commercial or open-source. This has resulted in a reduced acceptance of these data products by GIS and general user communities. Common problems and challenges experienced by these data users include difficulty when: Consuming data products from NASA Distributed Active Archive Centers (DAACs) that pre-date modern application software with commercial and open-source geospatial tools; Identifying an initial approach for developing a framework and plug-ins that interpret non-compliant data; Defining a methodology that is extensible across NASA Earth Observing System Data and Information System (EOSDIS), scientific communities, and GIS communities by enabling other data centers to construct their own plug-ins and adjust specific data products; and Promoting greater use of NASA Data and new analysis utilizing GIS tools. To address these challenges and to make EOS data products more accessible and interpretable by GIS applications, a collaborative approach has been taken that includes the NASA Langley Atmospheric Science Data Center (ASDC), Esri, George Mason University (GMU), and the Hierarchical Data Format (HDF) Group to create a framework and plugins to be applied to Geospatial Data Abstraction Library (GDAL). This framework and its plugins offer advantages of extensibility within NASA EOSDIS, permitting other data centers to construct their own plugins necessary to adjust their data products. In this session findings related to the framework and the development of GDAL plugins will be reviewed. Specifically, this session will offer a workshop to review documentation and training materials that have been generated for the purpose of guiding other NASA DAACs through the process of constructing plug-ins consistent with the framework as well as a review of the certification process by which the plugins can be independently verified as properly converting the data to the format and content required for use in GIS software.
NASA Technical Reports Server (NTRS)
Cooper, John F.; Kauristie, Kirsti; Weatherwax, Allan T.; Sheehan, Glenn W.; Smith, Roger W.; Sandahl, Ingrid; Ostgaard, Nikolai; Chernouss, Sergey; Thompson, Barbara J.; Peticolas, Laura;
2008-01-01
Polar, heliophysical, and planetary science topics related to the International Heliophysical and Polar Years 2007-2009 were addressed during this circumpolar video conference hosted January 23-29, 2808 at the new Barrow Arctic Research Center of the Barrow Arctic Science Consortium in Barrow, Alaska. This conference was planned as an IHY-IPY event science outreach event bringing together scientists and educational specialists for the first week of sunrise at subzero Arctic temperatures in Barrow. Science presentations spanned the solar system from the polar Sun to Earth, Moon, Mars, Jupiter, Saturn, and the Kuiper Belt. On-site participants experienced look and feel of icy worlds like Europa and Titan by being in the Barrow tundra and sea ice environment and by going "on the ice" during snowmobile expeditions to the near-shore sea ice environment and to Point Barrow, closest geographic point in the U.S. to the North Pole. Many science presentations were made remotely via video conference or teleconference from Sweden, Norway, Russia, Canada, Antarctica, and the United States, spanning up to thirteen time zones (Alaska to Russia) at various times. Extensive educational outreach activities were conducted with the local Barrow and Alaska North Slope communities and through the NASA Digital Learning Network live from the "top of the world" at Barrow. The Sun- Earth Day team from Goddard, and a videographer from the Passport to Knowledge project, carried out extensive educational interviews with many participants and native Inupiaq Eskimo residents of Barrow. Video and podcast recordings of selected interviews are available at http://sunearthday.nasa.gov/2008/multimedidpodcasts.php. Excerpts from these and other interviews will be included in a new high definition video documentary called "From the Sun to the Stars: The New Science of Heliophysics" from Passport to Knowledge that will later broadcast on NASA TV and other educational networks. Full conference proceedings are accessible at http://polargateways2008.org/.
Kinematic modeling of a double octahedral Variable Geometry Truss (VGT) as an extensible gimbal
NASA Technical Reports Server (NTRS)
Williams, Robert L., II
1994-01-01
This paper presents the complete forward and inverse kinematics solutions for control of the three degree-of-freedom (DOF) double octahedral variable geometry truss (VGT) module as an extensible gimbal. A VGT is a truss structure partially comprised of linearly actuated members. A VGT can be used as joints in a large, lightweight, high load-bearing manipulator for earth- and space-based remote operations, plus industrial applications. The results have been used to control the NASA VGT hardware as an extensible gimbal, demonstrating the capability of this device to be a joint in a VGT-based manipulator. This work is an integral part of a VGT-based manipulator design, simulation, and control tool.
Modeling the Earth System, volume 3
NASA Technical Reports Server (NTRS)
Ojima, Dennis (Editor)
1992-01-01
The topics covered fall under the following headings: critical gaps in the Earth system conceptual framework; development needs for simplified models; and validating Earth system models and their subcomponents.
Power and Propulsion System Design for Near-Earth Object Robotic Exploration
NASA Technical Reports Server (NTRS)
Snyder, John Steven; Randolph, Thomas M.; Landau, Damon F.; Bury, Kristen M.; Malone, Shane P.; Hickman, Tyler A.
2011-01-01
Near-Earth Objects (NEOs) are exciting targets for exploration; they are relatively easy to reach but relatively little is known about them. With solar electric propulsion, a vast number of interesting NEOs can be reached within a few years and with extensive flexibility in launch date. An additional advantage of electric propulsion for these missions is that a spacecraft can be small, enabling a fleet of explorers launched on a single vehicle or as secondary payloads. Commercial, flight-proven Hall thruster systems have great appeal based on their performance and low cost risk, but one issue with these systems is that the power processing units (PPUs) are designed for regulated spacecraft power architectures which are not attractive for small NEO missions. In this study we consider the integrated design of power and propulsion systems that utilize the capabilities of existing PPUs in an unregulated power architecture. Models for solar array and engine performance are combined with low-thrust trajectory analyses to bound spacecraft design parameters for a large class of NEO missions, then detailed array performance models are used to examine the array output voltage and current over a bounded mission set. Operational relationships between the power and electric propulsion systems are discussed, and it is shown that both the SPT-100 and BPT-4000 PPUs can perform missions over a solar range of 0.7 AU to 1.5 AU - encompassing NEOs, Venus, and Mars - within their operable input voltage ranges. A number of design trades to control the array voltage are available, including cell string layout, array offpointing during mission operations, and power draw by the Hall thruster system.
Software Defined Radio Architecture Contributions to Next Generation Space Communications
NASA Technical Reports Server (NTRS)
Kacpura, Thomas J.; Eddy, Wesley M.; Smith, Carl R.; Liebetreu, John
2015-01-01
Space communications architecture concepts, comprising the elements of the system, the interactions among them, and the principles that govern their development, are essential factors in developing National Aeronautics and Space Administration (NASA) future exploration and science missions. Accordingly, vital architectural attributes encompass flexibility, the extensibility to insert future capabilities, and to enable evolution to provide interoperability with other current and future systems. Space communications architectures and technologies for this century must satisfy a growing set of requirements, including those for Earth sensing, collaborative observation missions, robotic scientific missions, human missions for exploration of the Moon and Mars where surface activities require supporting communications, and in-space observatories for observing the earth, as well as other star systems and the universe. An advanced, integrated, communications infrastructure will enable the reliable, multipoint, high-data-rate capabilities needed on demand to provide continuous, maximum coverage for areas of concentrated activity. Importantly, the cost/value proposition of the future architecture must be an integral part of its design; an affordable and sustainable architecture is indispensable within anticipated future budget environments. Effective architecture design informs decision makers with insight into the capabilities needed to efficiently satisfy the demanding space-communication requirements of future missions and formulate appropriate requirements. A driving requirement for the architecture is the extensibility to address new requirements and provide low-cost on-ramps for new capabilities insertion, ensuring graceful growth as new functionality and new technologies are infused into the network infrastructure. In addition to extensibility, another key architectural attribute of the space communication equipment's interoperability with other NASA communications systems, as well as those communications and navigation systems operated by international space agencies and civilian and government agencies. In this paper, we review the philosophies, technologies, architectural attributes, mission services, and communications capabilities that form the structure of candidate next-generation integrated communication architectures for space communications and navigation. A key area that this paper explores is from the development and operation of the software defined radio for the NASA Space Communications and Navigation (SCaN) Testbed currently on the International Space Station (ISS). Evaluating the lessons learned from development and operation feed back into the communications architecture. Leveraging the reconfigurability provides a change in the way that operations are done and must be considered. Quantifying the impact on the NASA Space Telecommunications Radio System (STRS) software defined radio architecture provides feedback to keep the standard useful and up to date. NASA is not the only customer of these radios. Software defined radios are developed for other applications, and taking advantage of these developments promotes an architecture that is cost effective and sustainable. Developments in the following areas such as an updated operating environment, higher data rates, networking and security can be leveraged. The ability to sustain an architecture that uses radios for multiple markets can lower costs and keep new technology infused.
NASA Astrophysics Data System (ADS)
Vallianatos, Filippos
2015-04-01
Despite the extreme complexity that characterizes earthquake generation process, simple phenomenology seems to apply in the collective properties of seismicity. The best known is the Gutenberg-Richter relation. Short and long-term clustering, power-law scaling and scale-invariance have been exhibited in the spatio-temporal evolution of seismicity providing evidence for earthquakes as a nonlinear dynamic process. Regarding the physics of "many" earthquakes and how this can be derived from first principles, one may wonder, how can the collective properties of a set formed by all earthquakes in a given region, be derived and how does the structure of seismicity depend on its elementary constituents - the earthquakes? What are these properties? The physics of many earthquakes has to be studied with a different approach than the physics of one earthquake making the use of statistical physics necessary to understand the collective properties of earthquakes. Then a natural question arises. What type of statistical physics is appropriate to commonly describe effects from the microscale and crack opening level to the level of large earthquakes? An answer to the previous question could be non-extensive statistical physics, introduced by Tsallis (1988), as the appropriate methodological tool to describe entities with (multi) fractal distributions of their elements and where long-range interactions or intermittency are important, as in fracturing phenomena and earthquakes. In the present work, we review some fundamental properties of earthquake physics and how these are derived by means of non-extensive statistical physics. The aim is to understand aspects of the underlying physics that lead to the evolution of the earthquake phenomenon introducing the new topic of non-extensive statistical seismology. This research has been funded by the European Union (European Social Fund) and Greek national resources under the framework of the "THALES Program: SEISMO FEAR HELLARC" project. References F. Vallianatos, "A non-extensive approach to risk assessment", Nat. Hazards Earth Syst. Sci., 9, 211-216, 2009 F. Vallianatos and P. Sammonds "Is plate tectonics a case of non-extensive thermodynamics?" Physica A: Statistical Mechanics and its Applications, 389 (21), 4989-4993, 2010, F. Vallianatos, G. Michas, G. Papadakis and P. Sammonds " A non extensive statistical physics view to the spatiotemporal properties of the June 1995, Aigion earthquake (M6.2) aftershock sequence (West Corinth rift, Greece)", Acta Geophysica, 60(3), 758-768, 2012 F. Vallianatos and L. Telesca, Statistical mechanics in earth physics and natural hazards (editorial), Acta Geophysica, 60, 3, 499-501, 2012 F. Vallianatos, G. Michas, G. Papadakis and A. Tzanis "Evidence of non-extensivity in the seismicity observed during the 2011-2012 unrest at the Santorini volcanic complex, Greece" Nat. Hazards Earth Syst. Sci.,13,177-185, 2013 F. Vallianatos and P. Sammonds, "Evidence of non-extensive statistical physics of the lithospheric instability approaching the 2004 Sumatran-Andaman and 2011 Honshu mega-earthquakes" Tectonophysics, 590 , 52-58, 2013 G. Papadakis, F. Vallianatos, P. Sammonds, " Evidence of Nonextensive Statistical Physics behavior of the Hellenic Subduction Zone seismicity" Tectonophysics, 608, 1037 -1048, 2013 G. Michas, F. Vallianatos, and P. Sammonds, Non-extensivity and long-range correlations in the earthquake activity at the West Corinth rift (Greece) Nonlin. Processes Geophys., 20, 713-724, 2013
Stratigraphic and Earth System approaches to defining the Anthropocene
NASA Astrophysics Data System (ADS)
Steffen, Will; Leinfelder, Reinhold; Zalasiewicz, Jan; Waters, Colin N.; Williams, Mark; Summerhayes, Colin; Barnosky, Anthony D.; Cearreta, Alejandro; Crutzen, Paul; Edgeworth, Matt; Ellis, Erle C.; Fairchild, Ian J.; Galuszka, Agnieszka; Grinevald, Jacques; Haywood, Alan; Ivar do Sul, Juliana; Jeandel, Catherine; McNeill, J. R.; Odada, Eric; Oreskes, Naomi; Revkin, Andrew; Richter, Daniel deB.; Syvitski, James; Vidas, Davor; Wagreich, Michael; Wing, Scott L.; Wolfe, Alexander P.; Schellnhuber, H. J.
2016-08-01
Stratigraphy provides insights into the evolution and dynamics of the Earth System over its long history. With recent developments in Earth System science, changes in Earth System dynamics can now be observed directly and projected into the near future. An integration of the two approaches provides powerful insights into the nature and significance of contemporary changes to Earth. From both perspectives, the Earth has been pushed out of the Holocene Epoch by human activities, with the mid-20th century a strong candidate for the start date of the Anthropocene, the proposed new epoch in Earth history. Here we explore two contrasting scenarios for the future of the Anthropocene, recognizing that the Earth System has already undergone a substantial transition away from the Holocene state. A rapid shift of societies toward the UN Sustainable Development Goals could stabilize the Earth System in a state with more intense interglacial conditions than in the late Quaternary climate regime and with little further biospheric change. In contrast, a continuation of the present Anthropocene trajectory of growing human pressures will likely lead to biotic impoverishment and a much warmer climate with a significant loss of polar ice.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Motesharrei, Safa; Rivas, Jorge; Kalnay, Eugenia
Over the last two centuries, the impact of the Human System has grown dramatically, becoming strongly dominant within the Earth System in many different ways. Consumption, inequality, and population have increased extremely fast, especially since about 1950, threatening to overwhelm the many critical functions and ecosystems of the Earth System. Changes in the Earth System, in turn, have important feedback effects on the Human System, with costly and potentially serious consequences. However, current models do not incorporate these critical feedbacks. Here, we argue that in order to understand the dynamics of either system, Earth System Models must be coupled withmore » Human System Models through bidirectional couplings representing the positive, negative, and delayed feedbacks that exist in the real systems. In particular, key Human System variables, such as demographics, inequality, economic growth, and migration, are not coupled with the Earth System but are instead driven by exogenous estimates, such as United Nations population projections.This makes current models likely to miss important feedbacks in the real Earth–Human system, especially those that may result in unexpected or counterintuitive outcomes, and thus requiring different policy interventions from current models. Lastly, the importance and imminence of sustainability challenges, the dominant role of the Human System in the Earth System, and the essential roles the Earth System plays for the Human System, all call for collaboration of natural scientists, social scientists, and engineers in multidisciplinary research and modeling to develop coupled Earth–Human system models for devising effective science-based policies and measures to benefit current and future generations.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Motesharrei, Safa; Rivas, Jorge; Kalnay, Eugenia
Over the last two centuries, the impact of the Human System has grown dramatically, becoming strongly dominant within the Earth System in many different ways. Consumption, inequality, and population have increased extremely fast, especially since about 1950, threatening to overwhelm the many critical functions and ecosystems of the Earth System. Changes in the Earth System, in turn, have important feedback effects on the Human System, with costly and potentially serious consequences. However, current models do not incorporate these critical feedbacks. We argue that in order to understand the dynamics of either system, Earth System Models must be coupled with Humanmore » System Models through bidirectional couplings representing the positive, negative, and delayed feedbacks that exist in the real systems. In particular, key Human System variables, such as demographics, inequality, economic growth, and migration, are not coupled with the Earth System but are instead driven by exogenous estimates, such as United Nations population projections. This makes current models likely to miss important feedbacks in the real Earth–Human system, especially those that may result in unexpected or counterintuitive outcomes, and thus requiring different policy interventions from current models. The importance and imminence of sustainability challenges, the dominant role of the Human System in the Earth System, and the essential roles the Earth System plays for the Human System, all call for collaboration of natural scientists, social scientists, and engineers in multidisciplinary research and modeling to develop coupled Earth–Human system models for devising effective science-based policies and measures to benefit current and future generations.« less
Motesharrei, Safa; Rivas, Jorge; Kalnay, Eugenia; ...
2016-12-11
Over the last two centuries, the impact of the Human System has grown dramatically, becoming strongly dominant within the Earth System in many different ways. Consumption, inequality, and population have increased extremely fast, especially since about 1950, threatening to overwhelm the many critical functions and ecosystems of the Earth System. Changes in the Earth System, in turn, have important feedback effects on the Human System, with costly and potentially serious consequences. However, current models do not incorporate these critical feedbacks. Here, we argue that in order to understand the dynamics of either system, Earth System Models must be coupled withmore » Human System Models through bidirectional couplings representing the positive, negative, and delayed feedbacks that exist in the real systems. In particular, key Human System variables, such as demographics, inequality, economic growth, and migration, are not coupled with the Earth System but are instead driven by exogenous estimates, such as United Nations population projections.This makes current models likely to miss important feedbacks in the real Earth–Human system, especially those that may result in unexpected or counterintuitive outcomes, and thus requiring different policy interventions from current models. Lastly, the importance and imminence of sustainability challenges, the dominant role of the Human System in the Earth System, and the essential roles the Earth System plays for the Human System, all call for collaboration of natural scientists, social scientists, and engineers in multidisciplinary research and modeling to develop coupled Earth–Human system models for devising effective science-based policies and measures to benefit current and future generations.« less
The Emergence of Land Use as a Global Force in the Earth System
NASA Astrophysics Data System (ADS)
Ellis, E. C.
2015-12-01
Human societies have emerged as a global force capable of transforming the biosphere, hydrosphere, lithosphere, atmosphere and climate. As a result, the long-term dynamics of the Earth system can no longer be understood or predicted without understanding their coupling with human societal dynamics. Here, a general causal theory is presented to explain why behaviorally modern humans, unlike any prior multicellular species, gained this unprecedented capacity to reshape the Earth system and how this societal capacity has changed from the Pleistocene to the present and future. Sociocultural niche construction theory, building on existing theories of ecosystem engineering, niche construction, the extended evolutionary synthesis, cultural evolution, ultrasociality and social change, can explain both the long-term upscaling of human societies and their unprecedented capacity to transform the Earth system. Regime shifts in human sociocultural niche construction, from the clearing of land using fire, to shifting cultivation, to intensive agriculture, to global food systems dependent on fossil fuel combustion, have enabled human societies to scale up while gaining the capacity to reshape the global patterns and processes of biogeography, ecosystems, landscapes, biomes, the biosphere, and ultimately the functioning of the Earth system. Just as Earth's geophysical climate system shapes the long-term dynamics of energy and material flow across the "spheres" of the Earth system, human societies, interacting at global scale to form "human systems", are increasingly shaping the global dynamics of energy, material, biotic and information flow across the spheres of the Earth system, including a newly emerged anthroposphere comprised of human societies and their material cultures. Human systems and the anthroposphere are strongly coupled with climate and other Earth systems and are dynamic in response to evolutionary changes in human social organization, cooperative ecosystem engineering, non-kin exchange relationships, and energy systems. It is hoped that intentional societal efforts to alter the dynamics of human systems can ultimately move Earth systems towards more beneficial and less detrimental outcomes for both human societies and nonhuman species.
2017-12-08
This dramatic image features Hokusai in the foreground, famous for its extensive set of rays, some of which extend for over a thousand kilometers across Mercury's surface. The extensive, bright rays indicate that Hokusai is one of the youngest large craters on Mercury. Check out previously featured images to see high-resolution details of its central peaks, rim and ejecta blanket, and impact melt on its floor. This image was acquired as part of MDIS's high-incidence-angle base map. The high-incidence-angle base map complements the surface morphology base map of MESSENGER's primary mission that was acquired under generally more moderate incidence angles. High incidence angles, achieved when the Sun is near the horizon, result in long shadows that accentuate the small-scale topography of geologic features. The high-incidence-angle base map was acquired with an average resolution of 200 meters/pixel. The MESSENGER spacecraft is the first ever to orbit the planet Mercury, and the spacecraft's seven scientific instruments and radio science investigation are unraveling the history and evolution of the Solar System's innermost planet. During the first two years of orbital operations, MESSENGER acquired over 150,000 images and extensive other data sets. MESSENGER is capable of continuing orbital operations until early 2015. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington 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
NASA Technical Reports Server (NTRS)
Greenwood, R. C.; Howard, K. T.; Franchi, I. A.; Zolensky, M. E.; Buchanan, P. C.; Gibson, J. M.
2014-01-01
Water played a critical role in the early evolution of asteroids and planets, as well as being an essential ingredient for life on Earth. However, despite its importance, the source of water in the inner solar system remains controversial. Delivery of water to Earth via comets is inconsistent with their relatively elevated D/H ratios, whereas carbonaceous chondrites (CCs) have more terrestrial-like D/H ratios [1]. Of the eight groups into which the CCs are divided, only three (CI, CM, CR) show evidence of extensive aqueous alteration. Of these, the CMs form the single most important group, representing 34% of all CC falls and a similar percentage of finds (Met. Bull. Database). CM material also dominates the population of CC clasts in extraterrestrial samples [2, 3]. The Antarctic micrometeorites population is also dominated by CM and CI-like material and similar particles may have transported water and volatiles to the early Earth [4]. CCs, and CMs in particular, offer the best opportunity for investigating the evolution of water reservoirs in the early solar system. An important aspect of this problem involves identifying the anhydrous silicate component which co-accreted with ice in the CM parent body. A genetic relationship between the essentially anhydrous CO group and the CMs was proposed on the basis of oxygen isotope evidence [5]. However, previous CM whole-rock oxygen isotope data scattered about a line of approximately 0.5 that did not intersect the field of CO chondrites [5]. Here we discuss new oxygen isotope data which provides additional constraints on the relationship between CO and CM chondrites.
ACCESS Earth: Promoting Accessibility to Earth System Science for Students with Disabilities
NASA Astrophysics Data System (ADS)
Locke, S. M.; Cohen, L.; Lightbody, N.
2001-05-01
ACCESS Earth is an intensive summer institute for high school students with disabilities and their teachers that is designed to encourage students with disabilities to consider careers in earth system science. Participants study earth system science concepts at a Maine coastal estuary, using Geographic Information Systems, remote sensing, and field observations to evaluate the impacts of climate change, sea level rise, and development on coastal systems. Teachers, students, and scientists work together to adapt field and laboratory activities for persons with disabilities, including those with mobility and visual impairments. Other sessions include demonstrations of assistive technology, career discussions, and opportunities for students to meet with successful scientists with disabilities from throughout the U.S. The summer institute is one of several programs in development at the University of Southern Maine to address the problem of underrepresentation of people with disabilities in the earth sciences. Other projects include a mentoring program for high school students, a web-based clearinghouse of resources for teaching earth sciences to students with disabilities, and guidebooks for adaptation of popular published earth system science curricula for disabled learners.
Long-period noise source inversion in a 3-D heterogeneous Earth
NASA Astrophysics Data System (ADS)
Sager, K.; Ermert, L. A.; Afanasiev, M.; Boehm, C.; Fichtner, A.
2017-12-01
We have implemented a new method for ambient noise source inversion that fully honors finite-frequency wave propagation and 3-D heterogeneous Earth structure.Here, we present results of its first application to the Earth's long-period background signal, the hum, in a period band of around 120 - 300 s. In addition to being a computationally convenient test case, the hum is also the topic of ongoing research in its own right, because different physical mechanisms have been proposed for its excitation. The broad patterns of this model for South and North hemisphere winter are qualitatively consistent with previous long-term studies of the hum sources; however, thanks to methodological improvements, the iterative refinement, and the use of a comparatively extensive dataset, we retrieve a more detailed model in certain locations. In particular, our results support findings that the dominant hum sources are focused along coasts and shelf areas, particularly in the North hemisphere winter, with a possible though not well-constrained contribution of pelagic sources. Additionally, our findings indicate that hum source locations in the ocean, tentatively linked to locally high bathymetry, are important contributors particularly during South hemisphere winter. These results, in conjunction with synthetic recovery tests and observed cross-correlation waveforms, suggest that hum sources are rather narrowly concentrated in space, with length scales on the order of few hundred kilometers. Future work includes the extension of the model to spring and fall season and to shorter periods, as well as its use in full-waveform ambient noise inversion for 3-D Earth structure.
Extensive Radiation Shielding Analysis for Different Spacecraft Orbits
NASA Astrophysics Data System (ADS)
Çay, Yiǧit; Kaymaz, Zerefsan
2016-07-01
Radiation environment around Earth poses a great danger for spacecraft and causes immature de-orbiting or loss of the spacecraft in near Earth space environment. In this study, a student project has been designed to build a CubeSat, PolarBeeSail (PBS), with an orbit having inclination of 80°, 4 Re in perigee and 20 Re in apogee to study the polar magnetospheric environment. An extensive radiation dose analyses were carried out for PBS orbit, and integral and differential fluxes were calculated using SPENVIS tools. A shielding analysis was performed and an optimum Aluminum thickness, 3 mm, was obtained. These results for PBS were then compared for other orbits at different altitudes both for polar and equatorial orbits. For this purpose, orbital characteristics of POES-19 and GOES-15 were used. The resulting proton flux analyses, TID analyses, and further shielding studies were conducted; comparisons and recommendations were made for future design of spacecraft that will use these environments.
Modeling the Earth system in the Mission to Planet Earth era
NASA Technical Reports Server (NTRS)
Unninayar, Sushel; Bergman, Kenneth H.
1993-01-01
A broad overview is made of global earth system modeling in the Mission to Planet Earth (MTPE) era for the multidisciplinary audience encompassed by the Global Change Research Program (GCRP). Time scales of global system fluctuation and change are described in Section 2. Section 3 provides a rubric for modeling the global earth system, as presently understood. The ability of models to predict the future state of the global earth system and the extent to which their predictions are reliable are covered in Sections 4 and 5. The 'engineering' use of global system models (and predictions) is covered in Section 6. Section 7 covers aspects of an increasing need for improved transform algorithms and better methods to assimilate this information into global models. Future monitoring and data requirements are detailed in Section 8. Section 9 covers the NASA-initiated concept 'Mission to Planet Earth,' which employs space and ground based measurement systems to provide the scientific basis for understanding global change. Section 10 concludes this review with general remarks concerning the state of global system modeling and observing technology and the need for future research.
Earth Science Data Education through Cooking Up Recipes
NASA Astrophysics Data System (ADS)
Weigel, A. M.; Maskey, M.; Smith, T.; Conover, H.
2016-12-01
One of the major challenges in Earth science research and applications is understanding and applying the proper methods, tools, and software for using scientific data. These techniques are often difficult and time consuming to identify, requiring novel users to conduct extensive research, take classes, and reach out for assistance, thus hindering scientific discovery and real-world applications. To address these challenges, the Global Hydrology Resource Center (GHRC) DAAC has developed a series of data recipes that novel users such as students, decision makers, and general Earth scientists can leverage to learn how to use Earth science datasets. Once the data recipe content had been finalized, GHRC computer and Earth scientists collaborated with a web and graphic designer to ensure the content is both attractively presented to data users, and clearly communicated to promote the education and use of Earth science data. The completed data recipes include, but are not limited to, tutorials, iPython Notebooks, resources, and tools necessary for addressing key difficulties in data use across a broad user base. These recipes enable non-traditional users to learn how to use data, but also curates and communicates common methods and approaches that may be difficult and time consuming for these users to identify.
NASA Astrophysics Data System (ADS)
Newman, D. J.; Mitchell, A. E.
2015-12-01
At AGU 2014, NASA EOSDIS demonstrated a case-study of an OpenSearch framework for Earth science data discovery. That framework leverages the IDN and CWIC OpenSearch API implementations to provide seamless discovery of data through the 'two-step' discovery process as outlined by the Federation for Earth Sciences (ESIP) OpenSearch Best Practices. But how would an Earth Scientist leverage this framework and what are the benefits? Using a client that understands the OpenSearch specification and, for further clarity, the various best practices and extensions, a scientist can discovery a plethora of data not normally accessible either by traditional methods (NASA Earth Data Search, Reverb, etc) or direct methods (going to the source of the data) We will demonstrate, via the CWICSmart web client, how an earth scientist can access regional data on a regional phenomena in a uniform and aggregated manner. We will demonstrate how an earth scientist can 'globalize' their discovery. You want to find local data on 'sea surface temperature of the Indian Ocean'? We can help you with that. 'European meteorological data'? Yes. 'Brazilian rainforest satellite imagery'? That too. CWIC allows you to get earth science data in a uniform fashion from a large number of disparate, world-wide agencies. This is what we mean by Global OpenSearch.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Dye, Dennis; Ivanov, Valeriy; Saleska, Scott
This U.S-Brazil collaboration for GOAmazon has investigated a deceptively simple question: what controls the response of photosynthesis in Amazon tropical forests to seasonal variations in climate? In the past this question has been difficult to answer with modern earth system process models. We hypothesized that observed dry season increases in photosynthetic capacity are controlled by the phenology of leaf flush and litter fall, from which the seasonal pattern of LAI emerges. Our results confirm this hypothesis (Wu et al., 2016). Synthesis of data collected throughout the 3-year project period continues through December 31, 2017 under no-cost extensions granted to themore » project teams at University of Michigan and University of Arizona (Award 2). The USGS component (Award 1) ceased on the final date of the project performance period, December 31, 2016. This report summarizes the overall activities and achievements of the project, and constitutes the final project report for the USGS component. The University of Michigan will submit a separate final report that includes additional results and deliverables achieved during the period of their and the University of Arizona’s no-cost extension, which will end on December 31, 2017.« less
Forecast and Specification of Radiation Belt Electrons Based on Solar Wind Measurements
NASA Astrophysics Data System (ADS)
Li, X.; Barker, A.; Burin Des Roziers, E.
2003-12-01
Relativistic electrons in the Earth's magnetosphere are of considerable practical importance because of their effect on spacecraft and because of their radiation hazard to astronauts who perform extravehicular activity. The good correlation between solar wind velocity and MeV electron fluxes at geosynchronous orbit has long been established. We have developed a radial diffusion model, using solar wind parameters as the only input, to reproduce the variation of the MeV electrons at geosynchronous orbit. Based on this model, we have constructed a real-time model that forecasts one to two days in advance the daily averaged >2 MeV electron flux at geosynchronous orbit using real-time solar wind data from ACE. The forecasts from this model are available on the web in real time. A natural extension of our current model is to create a system for making quantitative forecasts and specifications of radiation belt electrons at different radial distances and different local times based on the solar wind conditions. The successes and obstacles associated with this extension will be discussed in this presentation.
Seismic evidence for widespread western-US deep-crustal deformation caused by extension
Moschetti, M.P.; Ritzwoller, M.H.; Lin, F.; Yang, Y.
2010-01-01
Laboratory experiments have established that many of the materials comprising the Earth are strongly anisotropic in terms of seismic-wave speeds. Observations of azimuthal and radial anisotropy in the upper mantle are attributed to the lattice-preferred orientation of olivine caused by the shear strains associated with deformation, and provide some of the most direct evidence for deformation and flow within the Earths interior. Although observations of crustal radial anisotropy would improve our understanding of crustal deformation and flow patterns resulting from tectonic processes, large-scale observations have been limited to regions of particularly thick crust. Here we show that observations from ambient noise tomography in the western United States reveal strong deep (middle to lower)-crustal radial anisotropy that is confined mainly to the geological provinces that have undergone significant extension during the Cenozoic Era (since 65 Myr ago). The coincidence of crustal radial anisotropy with the extensional provinces of the western United States suggests that the radial anisotropy results from the lattice-preferred orientation of anisotropic crustal minerals caused by extensional deformation. These observations also provide support for the hypothesis that the deep crust within these regions has undergone widespread and relatively uniform strain in response to crustal thinning and extension. ?? 2010 Macmillan Publishers Limited. All rights reserved.
SpaceCubeX: A Framework for Evaluating Hybrid Multi-Core CPU FPGA DSP Architectures
NASA Technical Reports Server (NTRS)
Schmidt, Andrew G.; Weisz, Gabriel; French, Matthew; Flatley, Thomas; Villalpando, Carlos Y.
2017-01-01
The SpaceCubeX project is motivated by the need for high performance, modular, and scalable on-board processing to help scientists answer critical 21st century questions about global climate change, air quality, ocean health, and ecosystem dynamics, while adding new capabilities such as low-latency data products for extreme event warnings. These goals translate into on-board processing throughput requirements that are on the order of 100-1,000 more than those of previous Earth Science missions for standard processing, compression, storage, and downlink operations. To study possible future architectures to achieve these performance requirements, the SpaceCubeX project provides an evolvable testbed and framework that enables a focused design space exploration of candidate hybrid CPU/FPGA/DSP processing architectures. The framework includes ArchGen, an architecture generator tool populated with candidate architecture components, performance models, and IP cores, that allows an end user to specify the type, number, and connectivity of a hybrid architecture. The framework requires minimal extensions to integrate new processors, such as the anticipated High Performance Spaceflight Computer (HPSC), reducing time to initiate benchmarking by months. To evaluate the framework, we leverage a wide suite of high performance embedded computing benchmarks and Earth science scenarios to ensure robust architecture characterization. We report on our projects Year 1 efforts and demonstrate the capabilities across four simulation testbed models, a baseline SpaceCube 2.0 system, a dual ARM A9 processor system, a hybrid quad ARM A53 and FPGA system, and a hybrid quad ARM A53 and DSP system.
Decadal opportunities for space architects
NASA Astrophysics Data System (ADS)
Sherwood, Brent
2012-12-01
A significant challenge for the new field of space architecture is the dearth of project opportunities. Yet every year more young professionals express interest to enter the field. This paper derives projections that bound the number, type, and range of global development opportunities that may be reasonably expected over the next few decades for human space flight (HSF) systems so those interested in the field can benchmark their goals. Four categories of HSF activity are described: human Exploration of solar system bodies; human Servicing of space-based assets; large-scale development of space Resources; and Breakout of self-sustaining human societies into the solar system. A progressive sequence of capabilities for each category starts with its earliest feasible missions and leads toward its full expression. The four sequences are compared in scale, distance from Earth, and readiness. Scenarios hybridize the most synergistic features from the four sequences for comparison to status quo, government-funded HSF program plans. Finally qualitative, decadal, order-of-magnitude estimates are derived for system development needs, and hence opportunities for space architects. Government investment towards human planetary exploration is the weakest generator of space architecture work. Conversely, the strongest generator is a combination of three market drivers: (1) commercial passenger travel in low Earth orbit; (2) in parallel, government extension of HSF capability to GEO; both followed by (3) scale-up demonstration of end-to-end solar power satellites in GEO. The rich end of this scale affords space architecture opportunities which are more diverse, complex, large-scale, and sociologically challenging than traditional exploration vehicle cabins and habitats.
Non-rocket Earth-Moon transport system
NASA Astrophysics Data System (ADS)
Bolonkin, Alexander
2003-06-01
This paper proposes a new transportation system for travel between Earth and Moon. This transportation system uses mechanical energy transfer and requires only minimal energy, using an engine located on Earth. A cable directly connects a pole of the Earth through a drive station to the lunar surface_ The equation for an optimal equal stress cable for complex gravitational field of Earth-Moon has been derived that allows significantly lower cable masses. The required strength could be provided by cables constructed of carbon nanotubes or carbon whiskers. Some of the constraints on such a system are discussed.
Non-equilibrium thermodynamics, maximum entropy production and Earth-system evolution.
Kleidon, Axel
2010-01-13
The present-day atmosphere is in a unique state far from thermodynamic equilibrium. This uniqueness is for instance reflected in the high concentration of molecular oxygen and the low relative humidity in the atmosphere. Given that the concentration of atmospheric oxygen has likely increased throughout Earth-system history, we can ask whether this trend can be generalized to a trend of Earth-system evolution that is directed away from thermodynamic equilibrium, why we would expect such a trend to take place and what it would imply for Earth-system evolution as a whole. The justification for such a trend could be found in the proposed general principle of maximum entropy production (MEP), which states that non-equilibrium thermodynamic systems maintain steady states at which entropy production is maximized. Here, I justify and demonstrate this application of MEP to the Earth at the planetary scale. I first describe the non-equilibrium thermodynamic nature of Earth-system processes and distinguish processes that drive the system's state away from equilibrium from those that are directed towards equilibrium. I formulate the interactions among these processes from a thermodynamic perspective and then connect them to a holistic view of the planetary thermodynamic state of the Earth system. In conclusion, non-equilibrium thermodynamics and MEP have the potential to provide a simple and holistic theory of Earth-system functioning. This theory can be used to derive overall evolutionary trends of the Earth's past, identify the role that life plays in driving thermodynamic states far from equilibrium, identify habitability in other planetary environments and evaluate human impacts on Earth-system functioning. This journal is © 2010 The Royal Society
NASA Technical Reports Server (NTRS)
1987-01-01
The Earth Observing System (EOS) represents a new approach to the study of the Earth. It consists of remotely sensed and correlative in situ observations designed to address important, interrelated global-scale processes. There is an urgent need to study the Earth as a complete, integrated system in order to understand and predict changes caused by human activities and natural processes. The EOS approach is based on an information system concept and designed to provide a long-term study of the Earth using a variety of measurement methods from both operational and research satellite payloads and continuing ground-based Earth science studies. The EOS concept builds on the foundation of the earlier, single-discipline space missions designed for relatively short observation periods. Continued progress in our understanding of the Earth as a system will come from EOS observations spanning several decades using a variety of contemporaneous measurements.
NASA Astrophysics Data System (ADS)
Marisaldi, Martino; Fuschino, Fabio; Labanti, Claudio; Tavani, Marco; Argan, Andrea; Del Monte, Ettore; Longo, Francesco; Barbiellini, Guido; Giuliani, Andrea; Trois, Alessio; Bulgarelli, Andrea; Gianotti, Fulvio; Trifoglio, Massimo
2013-08-01
Lightning and thunderstorm systems in general have been recently recognized as powerful particle accelerators, capable of producing electrons, positrons, gamma-rays and neutrons with energies as high as several tens of MeV. In fact, these natural systems turn out to be the highest energy and most efficient natural particle accelerators on Earth. Terrestrial Gamma-ray Flashes (TGFs) are millisecond long, very intense bursts of gamma-rays and are one of the most intriguing manifestation of these natural accelerators. Only three currently operative missions are capable of detecting TGFs from space: the RHESSI, Fermi and AGILE satellites. In this paper we review the characteristics of TGFs, including energy spectrum, timing structure, beam geometry and correlation with lightning, and the basic principles of the associated production models. Then we focus on the recent AGILE discoveries concerning the high energy extension of the TGF spectrum up to 100 MeV, which is difficult to reconcile with current theoretical models.
Terrestrial analysis of the organic component of comet dust.
Sandford, Scott A
2008-01-01
The nature of cometary organics is of great interest, both because these materials are thought to represent a reservoir of the original carbon-containing materials from which everything else in our solar system was made and because these materials may have played key roles in the origin of life on Earth. Because these organic materials are the products of a series of universal chemical processes expected to operate in the interstellar media and star-formation regions of all galaxies, the nature of cometary organics also provides information on the composition of organics in other planetary systems and, by extension, provides insights into the possible abundance of life elsewhere in the universe. Our current understanding of cometary organics represents a synthesis of information from telescopic and spacecraft observations of individual comets, the study of meteoritic materials, laboratory simulations, and, now, the study of samples collected directly from a comet, Comet P81/Wild 2.
NASA Technical Reports Server (NTRS)
Hofmann, Beda A.; Farmer, Jack; Chang, Sherwood (Technical Monitor)
1997-01-01
The recognition of biological signatures in ancient epithermal deposits has special relevance for studies of early blaspheme evolution and in exploring for past life on Mars. Recently, proposals for the existence of an extensive subsurface blaspheme on Earth, dominated by chemoautotrophic microbial life, has gained prominence. However, reports of fossilized microbial remains, or biosedimentary structures (e.g. stromatolites) from the deposits of ancient subsurface systems, are rare. Microbial preservation is favoured where high population densities co-exist with rapid mineral precipitation. Near-surface epithetical systems with strong gradients in temperature and redox are good candidates for the abundant growth and fossilization of microorganisms, and are also favorable environments for the precipitation of ore minerals. Therefore, we might expect microbial remain, to be particularly well preserved in various kinds of hydrothermal and diagenetic mineral precipitates that formed below the upper temperature limit for life (approx. 120 C).
Integration of a Fire Detector into a Spacecraft
NASA Technical Reports Server (NTRS)
Linford, R. M. F.
1972-01-01
A detector sensitive to only the ultraviolet radiation emitted by flames has been selected as the basic element of the NASA Skylab fire detection system. It is sensitive to approximately 10(exp -12)W of radiation and will detect small flames at distances in excess of 3m. The performance of the detector was verified by experiments in an aircraft flying zero-gravity parabolas to simulate the characteristics of a fire which the detector must sense. Extensive investigation and exacting design was necessary to exclude all possible sources of false alarms. Optical measurements were made on all the spacecraft windows to determine the amount of solar radiation transmitted. The lighting systems and the onboard experiments also were appraised for ultraviolet emissions. Proton-accelerator tests were performed to determine the interaction of the Earth's trapped radiation belts with the detectors and the design of the instrument was modified to negate these effects.
The Ion Propulsion System for the Asteroid Redirect Robotic Mission
NASA Technical Reports Server (NTRS)
Herman, Daniel A.; Santiago, Walter; Kamhawi, Hani; Polk, James E.; Snyder, John Steven; Hofer, Richard R.; Sekerak, Michael J.
2016-01-01
The Asteroid Redirect Robotic Mission is a Solar Electric Propulsion Technology Demonstration Mission (ARRM) whose main objectives are to develop and demonstrate a high-power solar electric propulsion capability for the Agency and return an asteroidal mass for rendezvous and characterization in a companion human-crewed mission. This high-power solar electric propulsion capability, or an extensible derivative of it, has been identified as a critical part of NASA'a future beyond-low-Earth-orbit, human-crewed exploration plans. Under the NASA Space Technology Mission Directorate the critical electric propulsion and solar array technologies are being developed. This paper presents the conceptual design of the ARRM ion propulsion system, the status of the NASA in-house thruster and power processing development activities, the status of the planned technology maturation for the mission through flight hardware delivery, and the status of the mission formulation and spacecraft acquisition.
NASA Technical Reports Server (NTRS)
Crump, William J.; Janik, Daniel S.; Thomas, L. Dale
1990-01-01
U.S. space missions have to this point used water either made on board or carried from earth and discarded after use. For Space Station Freedom, long duration life support will include air and water recycling using a series of physical-chemical subsystems. The Environmental Control and Life Support System (ECLSS) designed for this application must be tested extensively at all stages of hardware maturity. Human test subjects are required to conduct some of these tests, and the risks associated with the use of development hardware must be addressed. Federal guidelines for protection of human subjects require careful consideration of risks and potential benefits by an Institutional Review Board (IRB) before and during testing. This paper reviews the ethical principles guiding this consideration, details the problems and uncertainties inherent in current hardware testing, and presents an incremental approach to risk assessment for ECLSS testing.
Voyager Saturn encounter attitude and articulation control experience
NASA Technical Reports Server (NTRS)
Carlisle, G.; Hill, M.
1981-01-01
The Voyager attitude and articulation control system is designed for a three-axis stabilized spacecraft; it uses a biasable sun sensor and a Canopus Star Tracker (CST) for celestial control, as well as a dry inertial reference unit, comprised of three dual-axis dry gryos, for inertial control. A series of complex maneuvers was required during the first of two Voyager spacecraft encounters with Saturn (November 13, 1980); these maneuvers involved rotating the spacecraft simultaneously about two or three axes while maintaining accurate pointing of the scan platform. Titan and Saturn earth occulation experiments and a ring scattering experiment are described. Target motion compensation and the effects of celestial sensor interference are also considered. Failure of the CST, which required an extensive reevaluation of the star reference and attitude control mode strategy, is discussed. Results analyzed thus far show that the system performed with high accuracy, gathering data deeper into Saturn's atmosphere than on any previous planetary encounter.
Code of Federal Regulations, 2012 CFR
2012-10-01
...) Communication-satellite earth station complex. The term communication-satellite earth station complex includes transmitters, receivers, and communications antennas at the earth station site together with the... communication to terrestrial distribution system(s). (e) Communication-satellite earth station complex functions...
Code of Federal Regulations, 2011 CFR
2011-10-01
...) Communication-satellite earth station complex. The term communication-satellite earth station complex includes transmitters, receivers, and communications antennas at the earth station site together with the... communication to terrestrial distribution system(s). (e) Communication-satellite earth station complex functions...