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1

The Berkeley Earth Surface Temperature Averaging Methodology  

NASA Astrophysics Data System (ADS)

The Berkeley Earth Surface Temperature project has developed a new analysis framework for handling surface temperature records and constructing global temperature averages and maps. This has allowed us to achieve greater detail with less uncertainty than prior efforts. This framework adapts a weighted least-squares approach with spatial Kriging to allow us to utilize even very short and discontinuous temperature records. Further, we automate the process of assessing station reliability to allow data of unknown reliability to be included in the analysis. For the first time, this means that nearly all of the Earth ~40 thousand weather station time series can be directly incorporated into the construction of global temperature averages, rather than the 5-10 thousand long time series traditionally used. Applying the Berkeley Earth techniques, we broadly confirm the temperature histories presented by prior groups. However, the improved methodology allows the uncertainties to be reduced (often by 50%) and also has allowed the instrumental temperature record to be extended back to 1800. This session will present the Berkeley Earth Averaging Framework and results, with emphasis on the techniques employed.

Rohde, R. A.; Brillinger, D.; Curry, J. A.; Groom, D.; Jacobsen, B.; Muller, R. A.; Perlmutter, S.; Rosenfeld, A.; Wickham, C.; Wurtele, J.

2011-12-01

2

Nonlinear models from time series: The earth's mean surface temperature  

NASA Astrophysics Data System (ADS)

In the context of nonlinear dynamics and chaos theory, we study the apparent complexity of the earth's mean surface temperature. The apparent complexity refers to the irregular time dependence observed from the monthly measurements of the last 113 years (1356 data). Chaos theory is in some sense a formal method to extract simplicity from complexity, very complex behaviors can result from relatively simple nonlinear differential equations. Our main goal is to extract the possible simplicity underlying the earth's surface temperature time series. We briefly present some basic concepts of nonlinear dynamics and chaos theory including the invariant quantities of chaotic motion, i.e. those quantities not sensitive to changes in initial conditions. We then search for evidence of possible chaotic behavior in the Temperature time series. The earth's surface mean temperature as a macroscopic natural phenomenon is continuous in time and so it can be naturally modeled by a system of autonomous ordinary differential equations (ODE's). When this system consists of three or more differential equations containing nonlinear terms, we have the minimum (but not always sufficient) conditions for chaotic behavior. The definition of an invariant measure on the attractor allows us to construct an orthonormal base of polynomials to expand the vector field of ODE's. This polynomial orthonormal base eliminates the problem of multiparameter optimization. Additionally, a joint probability criterion to obtain the actual data with a given set of parameters is used to truncate the expansion of the vector field and find the best model that fits the data. The reconstructed fields are compared with models from first principles for the earth's surface temperature. In particular, for energy balance models that can be reasonably studied in temporal and spatial scales of monthly and global means. The sensitivity of the reconstructed vector field to variations on some reconstruction quantities is also investigated.

Gutierrez S., Rafael Maria

3

Earth and Mars: Evolution of Atmospheres and Surface Temperatures  

Microsoft Academic Search

Solar evolution implies, for contemporary albedos and atmospheric composition, global mean temperatures below the freezing point of seawater less than 2.3 aeons ago, contrary to geologic and paleontological evidence. Ammonia mixing ratios of the order of a few parts per million in the middle Precambrian atmosphere resolve this and other problems. Possible temperature evolutionary tracks for Earth and Mars are

Carl Sagan; George Mullen

1972-01-01

4

The Surface Temperature Characteristics of Earth's Active Lavas: Implications for the Design of Earth Observation Missions  

NASA Astrophysics Data System (ADS)

The detailed surface temperature distribution of an active lava body is an important boundary condition for estimating flow cooling and hence changes in rheology through time. These data can be difficult to acquire in-situ due to the temporally dynamic nature of the active lava bodies, their extreme thermal heterogeneity, and their propensity to occur in inaccessible areas and often over large spatial scales. This presentation describes results obtained from the analysis of 60 hyperspectral satellite images of active lava flows, domes, and lakes, acquired by NASA's Earth Observing-1 Hyperion sensor, which have been analyzed using sub-pixel mixture modeling techniques to constrain the temperature and radiant characteristics of real terrestrial lava bodies. The data reveal significant differences between the surface temperature distributions of lava flows (aa and pahoehoe), lava domes and lava lakes which relate primarily to a) eruption temperature, and b) the extent to which emplacement processes govern the rate at which lava flow surfaces are thermally renewed. The temperature data presented have wider implications. Volcanologists currently use many remote sensing instruments to quantify volcanic activity, and the fidelity of the imaging process (i.e. how accurately scene content is recorded in the image data), varies from instrument to instrument. Active lavas radiate prodigious amounts of energy in the infrared, often in excess of the maximum signal recordable by Earth observation satellites (Lmax), the dynamic ranges of which are optimized to observe surfaces at much lower temperatures. Such saturation is a significant problem for satellite volcanologists. The temperature data derived from Hyperion are used to simulate the response of some commonly used satellite remote sensing instruments to real lava flows to quantify the impact that saturation has on the measurements process. These results indicate the range of Lmax required to provide unsaturated data for Earth's active volcanoes, as well as quantifying the expected incidence of saturation using currently operational spacecraft. By defining target characteristics, the results are of relevance to the design of future Earth observation missions which have a strong volcanological science component, including NASA's proposed HyspIRI mission.

Wright, R.

2010-12-01

5

Estimation of the absolute surface air temperature of the Earth  

NASA Astrophysics Data System (ADS)

Average temperatures for the hemispheres and the globe are generally expressed as anomalies from a base period. Most users of these data and the underlying constituent gridded datasets do not require the values in absolute degrees, but a number of users might require this additional detail. An example group of users are climate modellers, who want to directly compare their simulations with reality in absolute units. Reanalysis datasets offer opportunities of assessing earlier absolute temperature estimates, but until recently their quality over data-sparse regions of the world was questionable. Here, we assess the latest Reanalysis (ERA-Interim) which is available from 1979 to the present against earlier direct estimates. Globally averaged ERA-Interim and the earlier direct estimates of absolute surface temperatures across the world are about 0.55°C different for the 1981-2010 period, with ERA-Interim cooler. The difference is only 0.29°C for the Northern Hemisphere, but larger at 0.81°C for the Southern Hemisphere. Spatially, the largest differences come from the Polar Regions, particularly the Antarctic.

Jones, P. D.; Harpham, C.

2013-04-01

6

Global Relationships among the Earth's Radiation Budget, Cloudiness, Volcanic Aerosols, and Surface Temperature.  

NASA Astrophysics Data System (ADS)

The analyses of Cess are extended to consider global relationships among the earth's radiation budget (including solar insulation and changes in optically active gass), cloudiness, solar constant, volcanic aerosols, and surface temperature. Interannual variability and correlations between Nimbus-7 THIR/TOMS cloud amount, ERB WFOV longwave, shortwaye, and net radiation, and SAM II aerosol optical depths, along with Hansen and Lebedeff's surface temperature analyses, are assessed.Solar luminosity is apparently related to the global surface temperature in the 1979-1990 time period based on the Nimbus-7 observations and an extended Hansen and Lebedeff temperature dataset. The 0.40°C range in observed global temperatures may be partitioned into a 0.15°C component due to a 2 W m2 change in the solar constant and a 0.22°C component due to the increasing concentration of CO2 and other greenhouse gases. A relatively large component of the variance in the global temperature, cloudiness, and radiation budget signals is due to interannual earth system variability over time periods much shorter than a solar cycle (e.g., 2-4 years), for which the solar luminosity experiences no comparable fluctuation.The Nimbus-7 observations indicate that the global, annual cloud amount varies by +0.3% to 0.5% with a pronounced quasi-biennial periodicity and is inversely proportional to the outgoing longwave flux and surface temperature. The time dependence of aerosols injected into the stratosphere by the explosive 1982 eruption of El Chichón is found to be important, along with the global cloud amount, in describing the time dependence of the earth's albedo during the period.The sign of the relationship between the earth's surface temperature and the net radiation is of fundamental importance. The Nimbus-7 ERB net radiation observations compared to surface temperature analyses imply a stable climate (at least about some set point that is dictated by other conditions such as the concentration of C02 and other greenhouse gases, that do not apply over the relatively short time interval considered here).When considering future mission we conclude that reliable and well-characterized satellite datasets with of ideally one to two decades or more are required to perform quantitative analyses of the relationships among different elements of the earth's climate system. To accomplish this, the instruments' calibration should be maintained and valid to a stability that permits the analysis of interannual global fluctuations at the 0.2% level.

Ardanuy, Philip E.; Kyle, H. Lee; Hoyt, Douglas

1992-10-01

7

Solar activity cycles in interannual global and hemisphere temperatures on the earth's surface  

NASA Astrophysics Data System (ADS)

We study solar activity and surface temperature variations (in the first place at periods of main solar cycles: ˜ 11 and ˜ 22 yrs) to understand a possible influence of solar activity on climate changes. The problems are trends, quasi-periodicities and noise in solar and climate processes. The basic idea in identifying a possible origin of the observed increase in the Earth's global temperature (GT) is to look for low frequency variations in the data that have sufficient amplitudes. To describe trends and non-stationary variations in the data we use a method of a non-linear spectral analysis (MGM). MGM is capable of making a self-consistent selection of trends from a data set and singling out harmonics with varying phase and amplitude. We use data: of sunspot numbers W for the period 1700-2003; of GT, North and South Hemisphere surface temperatures (NHT, SHT) for 1000-1990. Spectral peaks of our spectra have confidence statistical level higher than 95%. Longest non-stationary sinusoid of MGM spectrum of GT at T˜ 1000 yr. has the highest power. This cycle has the least values for Maunder Minimum (MM): its amplitude was decreasing before MM and increasing after and present. Trend in W and cycle at T˜ 1000 yr in GT show synchronous increasing for 1700-2000. We detected clear correlation of time variations of magnetic solar cycle at T=22.1 yr. and cycle at the same period in GT (both non-stationary) for all interval 1700-2000. The NHT and SHT at T=22.1 yr. vary in nearly opposite phase and have different amplitudes. Analysis shows that even 11-yr solar cycles correspond to cooling of GT, but odd ones to warming. Based on the fact that magnetic solar cycle in W reflects asymmetry of solar activity relative to sign of solar magnetic field, we present a physical mechanism of influence of 22-yr solar cycle on temperature variations. Our idea is based on influence of the solar wind electric fields E on global atmospheric circuit. These E-fields (transmitted into polar ionosphere for a reconnection) modulate potential difference and surface charge on the boundaries of upper and lower atmosphere; arising currents in global atmospheric electric circuit change angular momentum of zone atmospheric winds (that are responsible for climate changes). Observations of latitude variations of annual velocity of zonal wind and angular velocity of rotation of the lower atmosphere, presence of T=22-yr. in spectra of rotation of the Earth and Z-component of geomagnetic variations confirm our mechanism. However, cycle at T=22 yr. has small power in the GT spectrum. Power cycles in temperature spectra (such as at T=300 yr, T=210 yr) can not be explained in terms of this mechanism. We elaborate such a new additional mechanism for now.

Kuznetsova, T. V.; Tsirulnik, L. B.

8

Earth's Changing Surface  

NSDL National Science Digital Library

This site presents changes in the crust and climate of Earth by investigating aspects such as the rock cycle, rock dating, climate and variables that affect the climate, and other processes that change the crust of the Earth. These topics include: the atmosphere and surface of Earth; volcanoes and earthquakes; igneous, sedimentary, and metamorphic rocks; and weathering and erosion. There are also laboratory activities to explore radioactive dating and the asthenosphere as well as a rock formation quiz.

9

Negative feedback mechanism for the long-term stabilization of earth's surface temperature  

Microsoft Academic Search

We suggest that the partial pressure of carbon dioxide in the atmosphere is buffered, over geological time scales, by a negative feedback mechanism in which the rate of weathering of silicate minerals (followed by deposition of carbonate minerals) depends on surface temperature, and surface temperature, in turn, depends on carbon dioxide partial pressure through the green effect. Although the quantitative

James C. G. Walker; P. B. Hays; J. F. Kasting

1981-01-01

10

Earth Exploration Toolbook Chapter: Detecting El NiÃo in Sea Surface Temperature Data  

NSDL National Science Digital Library

DATA: Sea Surface Temperature (SST). TOOL: My World GIS. SUMMARY: Examine 15 years of SST data from the Pacific Marine Environmental Laboratory. Create and analyze average SST maps to identify El Nino and La Nina events.

Smith, David; Youngman, Betsy

11

Calculations of temperature and barometric effects for cosmic ray flux on the Earth surface using the CORSIKA code  

NASA Astrophysics Data System (ADS)

Results of simulation of the spectra of cosmic rays (CR) on the Earth surface by means of the CORSIKA code are presented. For simulation, a standard model of the atmosphere and additional ones (with changed temperature profile and changed values of pressure at sea level) were used. Spectra of particles were obtained in the energy range 0.1 - 100 GeV for five values of zenith angle (0, 15, 30, 45 and 60 degrees) and, for the vertical direction, for several altitudes (0 m, 500 m, 1000 m and 1500 m above sea level). Barometric and temperature coefficients for various components of CR were estimated from the simulation data.

Kovylyaeva, A. A.; Dmitrieva, A. N.; Tolkacheva, N. V.; Yakovleva, E. I.

2013-02-01

12

Twelve-month running trends from Earth Radiation Budget Satellite (ERBS) active-cavity radiometric measurements and global surface temperatures  

NASA Astrophysics Data System (ADS)

Four earth-viewing nonscanning active cavity radiometers of the ERBS (Earth Radiation Budget Satellite) have been measuring the radiation arising from the earth-atmosphere system since its" launch day, October 5, 1984. The ERBS spacecraft was placed in a non-sun-synchronous trajectory inclined at 57°. Two radiometers out of four, namely the wide field-of-view total (WFOV-T) radiometer which measures the radiation in the total spectral band of 0.2 - 100 ?m, and the wide-field-of-view shortwave (WFOV-SW) radiometer measures the Earth"s reflected radiation in the wavelength region of 0.2 - 5 ?m were used in this study. These sensors were calibrated continuously by observing the in-flight internal black bodies as well as the Sun every two weeks. The WFOV-T channel was found very stable within 0.1%. The monthly flux values of the ERBS nonscanning active cavity radiometers at satellite altitude and the corresponding NCDC (National Climatic Data Center) global surface temperature data for the period of fifteen years (1985-1999) were used in this paper. The effect of Mt. Pinatubo eruption is very clearly noticeable in the running trends of both WFOV-T and WFOV-SW radiometric measurements. Further the resulting twelve month running trends derived from the outgoing longwave radiation was found to follow the twelve month running trend determined from the global surface temperature data set. Both trends are real and increasing. The "global-cooling-like" event caused by the Mt. Pinatubo eruption was also found under both day and nighttime conditions.

Pandey, Dhirendra K.; Lee, Robert B., III; Paden, Jack; Bush, Kathryn A.; Snyder, Dianne; Wilson, Robert S.; Banks, Waldena; Al-Hajjah, Aiman; Thomas, Susan

2004-02-01

13

EARTH SCIENCES RESEARCH JOURNAL GROUND SURFACE TEMPERATURE HISTORIES INFERRED FROM 15 BOREHOLES TEMPERATURE PROFILES: COMPARISON OF TWO APPROACHES  

Microsoft Academic Search

Understanding the climate change processes requires application of special methodologies for revealing a ground surface temperature history (GSTH). It was proved by different authors that the GSTH may be determined on the basis of analysis of the temperature field observed in short boreholes. In this paper, the authors analyze four mathematical models describing the GSTH: (1) sudden change, (2) linear

L. V. Eppelbaum; I. M. Kutasov; G. Barak

14

Earth's Surface Features  

NSDL National Science Digital Library

Students work in pairs on this worksheet and strengthen their background knowledge by identifying different features in photographs of Earth's surface. Then to build on this base, the students need to determine the key processes that form each of the features. To address a common misconception, students read a debate between two hypothetical students and need to determine which student is stating the scientifically correct idea. The project is summarized by a question posed about the features on a hypothetical planet.

Smay, Jessica J.

15

Earth's Changing Surface  

NSDL National Science Digital Library

This activity was designed to demonstrate how limestone caves are formed and are later decorated by speleothems. It may be supported by the Exploring Caves segment of the video 'Earth's Changing Surface,' but does not require it. As students complete this activity they will be able to explain how caves are formed, demonstrate how speleothems are formed, and describe the difference between stalactites and stalagmites. Provided are a list of objectives, a list of materials, detailed procedures, vocabulary, academic standards, and a three-point rubric to evaluate students' work during the lesson.

16

Rational design of long-wave infrared band for application of the earth surface temperature observation  

NASA Astrophysics Data System (ADS)

For argumentation of feasibility of LST (Land Surface Temperature) retrieval using 8-10 ?m infrared band, this paper focuses on design of long-wave infrared band based on theory research. Basis of thermal infrared radiative transfer and atmospheric simulation, the paper analyses atmospheric effect on different long-wave infrared and obtain a preliminary selection of potential spectral channels. Several configurations of long-wave infrared spectral band were selected to perform in Split-Window algorithm and the relation of LST retrieval precision with error source was analyzed. Results indicate the scheme of LST retrieval using 8.0-9.0?m long-wave infrared is feasibility for needed retrieval precision.

Bao, Yunfei; He, Hongyan; Zhou, Feng

2012-12-01

17

The complex dynamics of the seasonal component of Earth's surface temperature  

Microsoft Academic Search

The dynamics of the climate system has been investigated by analyzing the complex seasonal oscillation of monthly averaged temperatures recorded at 1167 stations covering the whole USA. We found the presence of an orbit-climate relationship on time scales remarkably shorter than the Milankovitch period related to the nutational forcing. The relationship manifests itself through occasional destabilization of the phase of

A. Vecchio; V. Capparelli; V. Carbone

2010-01-01

18

The CRUTEM4 land-surface air temperature dataset: construction, previous versions and dissemination via Google Earth  

NASA Astrophysics Data System (ADS)

The CRUTEM4 (Climatic Research Unit Temperature version 4) land-surface air temperature dataset is one of the most widely used records of the climate system. Here we provide an important additional dissemination route for this dataset: online access to monthly, seasonal and annual data values and timeseries graphs via Google Earth. This is achieved via an interface written in Keyhole Markup Language (KML) and also provides access to the underlying weather station data used to construct the CRUTEM4 dataset. A mathematical description of the construction of the CRUTEM4 dataset (and its predecessor versions) is also provided, together with an archive of some previous versions and a recommendation for identifying the precise version of the dataset used in a particular study. The CRUTEM4 dataset used here is available from doi:10.5285/EECBA94F-62F9-4B7C-88D3-482F2C93C468.

Osborn, T. J.; Jones, P. D.

2013-10-01

19

Landsat: Looking at Earth's Surface  

NASA Video Gallery

The Landsat program is the longest continuous global record of the Earth's surface, and continues to deliver both visually stunning and scientifically valuable images of our planet. > Landsat website > Download high-res video

Jim Wilson

2010-03-22

20

DIATOMACEOUS EARTH SURFACE TREATMENT FOR STORED WHEAT  

Technology Transfer Automated Retrieval System (TEKTRAN)

Diatomaceous earth (DE) can be used as a surface treatment in stored wheat to control pest infestations. However, it is not known how the thickness of the DE-treated wheat layer or grain temperature impacts effectiveness. When adult Rhizopertha dominica (F.), lesser grain borers, were released in e...

21

Earth Surface Processes, Landforms and Sediment Deposits  

NASA Astrophysics Data System (ADS)

Earth surface processes, landforms and sediment deposits are intimately related - involving erosion of rocks, generation of sediment, and transport and deposition of sediment through various Earth surface environments. These processes, and the landforms and deposits that they generate, have a fundamental bearing on engineering, environmental and public safety issues; on recovery of economic resources; and on our understanding of Earth history. This unique textbook brings together the traditional disciplines of sedimentology and geomorphology to explain Earth surface processes, landforms and sediment deposits in a comprehensive and integrated way. It is the ideal resource for a two-semester course in sedimentology, stratigraphy, geomorphology, and Earth surface processes from the intermediate undergraduate to beginning graduate level. The book is also accompanied by a website hosting illustrations and material on field and laboratory methods for measuring, describing and analyzing Earth surface processes, landforms and sediments.

Bridge, John; Demicco, Robert

22

Sun's Impact On Earth's Temperature  

NSDL National Science Digital Library

This lesson plan is part of the Center for Educational Resources (CERES), a series of web-based astronomy lessons created by a team of master teachers, university faculty, and NASA researchers. In this activity, students view NASA images and movies of Venus, Earth, and Mars to deduce weather patterns and manipulate computer models to test competing hypotheses. This lesson contains expected outcomes for students, materials, background information, follow-up questions, and assessment procedures.

Tuthill, George; Obbink, Kim

23

Initiation of clement surface conditions on the earliest Earth  

PubMed Central

In the beginning the surface of the Earth was extremely hot, because the Earth as we know it is the product of a collision between two planets, a collision that also created the Moon. Most of the heat within the very young Earth was lost quickly to space while the surface was still quite hot. As it cooled, the Earth's surface passed monotonically through every temperature regime between silicate vapor to liquid water and perhaps even to ice, eventually reaching an equilibrium with sunlight. Inevitably the surface passed through a time when the temperature was around 100°C at which modern thermophile organisms live. How long this warm epoch lasted depends on how long a thick greenhouse atmosphere can be maintained by heat flow from the Earth's interior, either directly as a supplement to insolation, or indirectly through its influence on the nascent carbonate cycle. In both cases, the duration of the warm epoch would have been controlled by processes within the Earth's interior where buffering by surface conditions played little part. A potentially evolutionarily significant warm period of between 105 and 107 years seems likely, which nonetheless was brief compared to the vast expanse of geological time.

Sleep, N. H.; Zahnle, K.; Neuhoff, P. S.

2001-01-01

24

Effect of rare earth on the thermostability and the surface area of auto-catalyst washcoats  

Microsoft Academic Search

In this paper, the influence of rare earth on the thermostability and surface area of auto-catalyst washcoating was studied by XRD and BET analysis. The results showed that the modification of rare earth was positively effective for the thermostability of ?-alumina washcoating. With rare earth, the transformation temperature from ?-alumina to ?-alumina was increased from 800°C to 1200°C. Rare earth

Hongmei Ding; Duan Weng; Xiaodong Wu

2000-01-01

25

Quantitative Modeling of Earth Surface Processes  

NASA Astrophysics Data System (ADS)

This textbook describes some of the most effective and straightforward quantitative techniques for modeling Earth surface processes. By emphasizing a core set of equations and solution techniques, the book presents state-of-the-art models currently employed in Earth surface process research, as well as a set of simple but practical research tools. Detailed case studies demonstrate application of the methods to a wide variety of processes including hillslope, fluvial, aeolian, glacial, tectonic, and climatic systems. Exercises at the end of each chapter begin with simple calculations and then progress to more sophisticated problems that require computer programming. All the necessary computer codes are available online at www.cambridge.org/9780521855976. Assuming some knowledge of calculus and basic programming experience, this quantitative textbook is designed for advanced geomorphology courses and as a reference book for professional researchers in Earth and planetary science looking for a quantitative approach to Earth surface processes.

  • More details...
  • Pelletier, Jon D.

    26

    Reducing greenhouses and the temperature history of earth and Mars  

    Microsoft Academic Search

    It has been suggested that NH3 and other reducing gases were present in the earth's primitive atmosphere, enhancing the global greenhouse effect; data obtained through isotopic archeothermometry support this hypothesis. Computations have been applied to the evolution of surface temperatures on Mars, considering various bolometric albedos and compositions. The results are of interest in the study of Martian sinuous channels

    CARL SAGAN

    1977-01-01

    27

    Comparing the Surfaces of Earth and Mars  

    NSDL National Science Digital Library

    Comparing the Surfaces of Earth and Mars is a Windows to the Universe Exploratour and provides information and images about different features found on the surface and the geography of both planets: continents, craters, volcanoes, plate tectonics, rocks, soils, water, and polar caps. Windows to the Universe is a user-friendly learning system pertaining to the Earth and Space sciences. The objective of this project is to develop an innovative and engaging web site that spans the Earth and Space sciences and includes a rich array of documents, including images, movies, animations, and data sets that explore the Earth and Space sciences and the historical and cultural ties between science, exploration and the human experience. Links at the top of each page allow users to navigate between beginner, intermediate, and advanced options for each topic level.

    Johnson, Roberta

    2000-07-01

    28

    National Center for Earth-surface Dynamics  

    NSDL National Science Digital Library

    NCED (the National Center for Earth-surface Dynamics) is a National Science Foundation Science and Technology Center. We began operation in August, 2002; we're headquartered at the St. Anthony Falls Laboratory at the University of Minnesota. Our purpose is to catalyze development of an integrated, predictive science of the processes shaping the surface of the Earth in order to transform management of ecosystems, resources, and land use. In concert with our integrative research efforts, we strive to bring our methods and results to students, the public, and practitioners in agencies and industry.

    Dynamics, National C.

    29

    Earth Surface Patterns in 200 Years (Invited)  

    Microsoft Academic Search

    What kinds of patterns will characterize Earth's surface in 200 years? This question is addressed using a complex systems dynamical framework for distinct levels of description in a hierarchy, in which time scale and spatial extent increase and number of variables decrease with level, and in which levels are connected nonlinearly to each other via self-organization and slaving and linearly

    B. Werner

    2009-01-01

    30

    The Human Transformation of the Earth's Surface.  

    ERIC Educational Resources Information Center

    Reviews the tremendous transformation that human beings have wrought on the earth's surface from the Holocene to the present. Traces this transformation through various stages: the emergence and development of agriculture, agricultural impact and land degradation, ecological and political imperialism, industrialization, and environmental…

    Roberts, Neil

    1996-01-01

    31

    The Human Transformation of the Earth's Surface.  

    ERIC Educational Resources Information Center

    |Reviews the tremendous transformation that human beings have wrought on the earth's surface from the Holocene to the present. Traces this transformation through various stages: the emergence and development of agriculture, agricultural impact and land degradation, ecological and political imperialism, industrialization, and environmental…

    Roberts, Neil

    1996-01-01

    32

    Mudball: Surface dust and Snowball Earth deglaciation  

    Microsoft Academic Search

    Recent modeling results have raised doubts about the ability to deglaciate from a global glaciation at atmospheric carbon dioxide levels that are realistic for a Neoproterozoic Snowball Earth. Here we argue that over the lifetime of a Snowball event, ice dynamics should lead to the development of a layer of continental and volcanic dust at the ice surface in the

    Dorian S. Abbot; Raymond T. Pierrehumbert

    2010-01-01

    33

    Global Sea Surface Temperature and MODIS  

    NSDL National Science Digital Library

    MODIS provides frequent (every 1-2 days) global views of many of the Earths vital signs. This image shows a true-color land surface and a false color sea surface temperature map (red and yellow are warmer, blues are cooler).

    Snodgrass, Stuart; Kaufman, Yoram

    2000-04-19

    34

    Titan's Surface Brightness Temperatures  

    NASA Astrophysics Data System (ADS)

    Radiance from the surface of Titan can be detected from space through a spectral window of low opacity in the thermal infrared at 19 ?m (530 cm-1). By combining Composite Infrared Spectrometer observations from Cassini's first four years, we have mapped the latitude distribution of zonally averaged surface brightness temperatures. The measurements are corrected for atmospheric opacity as derived from the dependence of radiance on the emission angle. At equatorial latitudes near the Huygens landing site, the surface brightness temperature is found to be 93.7 ± 0.6 K, in excellent agreement with the in situ measurement. Temperature decreases toward the poles, reaching 90.5 ± 0.8 K at 87°N and 91.7 ± 0.7 K at 88°S. The meridional distribution of temperature has a maximum near 10°S, consistent with Titan's late northern winter.

    Jennings, D. E.; Flasar, F. M.; Kunde, V. G.; Samuelson, R. E.; Pearl, J. C.; Nixon, C. A.; Carlson, R. C.; Mamoutkine, A. A.; Brasunas, J. C.; Guandique, E.; Achterberg, R. K.; Bjoraker, G. L.; Romani, P. N.; Segura, M. E.; Albright, S. A.; Elliott, M. H.; Tingley, J. S.; Calcutt, S.; Coustenis, A.; Courtin, R.

    2009-02-01

    35

    Earth  

    NSDL National Science Digital Library

    This NASA (National Aeronautics and Space Administration) planet profile provides data and images of the planet Earth. These data include planet size, orbit facts, distance from the Sun, rotation and revolution times, temperature, atmospheric composition, density, surface materials and albedo. Images with descriptions show Earth features such as the Ross Ice Shelf in Antarctica, Simpson Desert in Australia, Mt. Etna in Sicily, the Cassiar Mountains in Canada, the Strait of Gibraltar, Mississippi River, Grand Canyon, Wadi Kufra Oasis in Libya, and Moon images such as Hadley Rille, Plum Crater, massifs and Moon rocks. These images were taken with the Galileo Spacecraft and by the Apollo missions.

    36

    Global Surface Temperature Change  

    NASA Astrophysics Data System (ADS)

    We update the Goddard Institute for Space Studies (GISS) analysis of global surface temperature change, compare alternative analyses, and address questions about perception and reality of global warming. Satellite-observed night lights are used to identify measurement stations located in extreme darkness and adjust temperature trends of urban and periurban stations for nonclimatic factors, verifying that urban effects on analyzed global change are small. Because the GISS analysis combines available sea surface temperature records with meteorological station measurements, we test alternative choices for the ocean data, showing that global temperature change is sensitive to estimated temperature change in polar regions where observations are limited. We use simple 12 month (and n × 12) running means to improve the information content in our temperature graphs. Contrary to a popular misconception, the rate of warming has not declined. Global temperature is rising as fast in the past decade as in the prior 2 decades, despite year-to-year fluctuations associated with the El Niño-La Niña cycle of tropical ocean temperature. Record high global 12 month running mean temperature for the period with instrumental data was reached in 2010.

    Hansen, J.; Ruedy, R.; Sato, M.; Lo, K.

    2010-12-01

    37

    Global Surface Temperature Change  

    Microsoft Academic Search

    We update the Goddard Institute for Space Studies (GISS) analysis of global surface temperature change, compare alternative analyses, and address questions about perception and reality of global warming. Satellite-observed nightlights are used to identify measurement stations located in extreme darkness and adjust temperature trends of urban and peri-urban stations for non-climatic factors, verifying that urban effects on analyzed global change

    J. Hansen; R. Ruedy; M. Sato

    38

    On Similarities Between the Earth Rotation and Temperature Changes  

    NASA Astrophysics Data System (ADS)

    Earths rotation reflects processes in the atmosphere, ocean, Earths interior. The similarities between the global temperature oscillations and Earths rotation speed changes are well known, but still are not explained. We also have found similarities between ~ 20-year temperature oscillations, Chandler excitation envelope and cycle of regression of the Moon orbital nodes. In this short article we want to attract attention to this fact.

    Zotov, L. V.

    39

    Gravity increased by lunar surface temperature  

    NASA Astrophysics Data System (ADS)

    Quantitatively large effects of lunar surface temperature on apparent gravitational force measured by lunar laser ranging (LLR) and lunar perigee may challenge widely accepted theories of gravity. LLR data grouped by days from full moon shows the moon is about 5 percent closer to earth at full moon compared to 8 days before or after full moon. In a second, related result, moon perigees were least distant in days closer to full moon. Moon phase was used as proxy independent variable for lunar surface temperature. The results support the prediction by binary mechanics that gravitational force increases with object surface temperature.

    Keene, James

    2013-04-01

    40

    Remote sensing of the Dead Sea surface temperature  

    Microsoft Academic Search

    The Dead Sea is a unique terminal lake located at the lowest place on Earth's surface. It has the highest surface temperature, salinity, and density among Earth's large water bodies, and its level is currently dropping at a rate of ?1 m\\/a. Knowledge of the Dead Sea thermal and saline structure is based on meteorological and hydrological measurements from a

    R. Nehorai; I. M. Lensky; N. G. Lensky; S. Shiff

    2009-01-01

    41

    Remote sensing of the Dead Sea surface temperature  

    Microsoft Academic Search

    The Dead Sea is a unique terminal lake located at the lowest place on Earth's surface. It has the highest surface temperature, salinity, and density among Earth's large water bodies, and its level is currently dropping at a rate of ˜1 m\\/a. Knowledge of the Dead Sea thermal and saline structure is based on meteorological and hydrological measurements from a

    R. Nehorai; I. M. Lensky; N. G. Lensky; S. Shiff

    2009-01-01

    42

    The pressure-weakening effect in super-Earths: Consequences of a decrease in lower mantle viscosity on surface dynamics  

    Microsoft Academic Search

    The quest to identify habitable planets has raised interest in the surface dynamics of terrestrial bodies. In this context super-Earths (a new class of exoplanets) have become of special interest in the past decade. Scalings to super-Earth sizes, when compared to the Earth, suggest changes to convective stresses and mantle temperatures which can cause either an increase in surface mobility

    C. Stein; A. Finnenkötter; J. P. Lowman; U. Hansen

    2011-01-01

    43

    Contamination of optical surfaces in Earth orbit  

    NASA Astrophysics Data System (ADS)

    Glass and glass ceramic samples exposed to the low earth orbit environment for approximately 5.5 years on the Long Duration Exposure Facility (LDEF) were found to display limited degradation in optical transmission. Commercial optical quality fused silica samples display decreases in transmission in the 200 to 400 nm wavelength region, and this degradation appears to be a consequence of surface contamination. The contamination, found only on internal surfaces of samples, was measured by medium energy backscattering spectrometry and found to be primarily carbon. Additional thin film contamination by a species with atomic mass near 64, which was present at the level of about 8 x 10 exp 14/sq. cm has not been identified. These observations are consistent with the interpretation that organic binders used in the black absorbing paint (Chem Glaze Z-306) inside the sample holding tray were concentrated in the vicinity of the samples and photolytically cracked by solar UV radiation. The resulting decomposition products were deposited on the interior sample surface and gave rise to the optical transmission loss. No detectable contamination was observed on the external or space exposed surface of the samples. No measurable damage was detected which could be attributed to the direct action of gamma or UV radiation on the glass samples. These results emphasize the need for special precautions in the preparation of spacecraft carrying precision optical components on long duration missions.

    Kinser, Donald L.; Weller, Robert A.; Mendenhall, M. H.; Wiedlocher, D. E.; Nichols, R.; Tucker, D.; Whitaker, A.

    1992-01-01

    44

    Sea Surface Temperature Variability  

    Microsoft Academic Search

    A weekly mean Multi-Channel Sea Surface Temperature (MCSST) data set was used to study\\u000a seasonal and interannual variability of SSTs averaged over four regions of the Caspian Sea individually\\u000a (Northern, Middle, and Southern Caspian, and Kara-Bogaz-Gol Bay) and SST trends during 1982--2000.\\u000a The SST fields averaged for individual months of four hydrological seasons (February, April, August,\\u000a and October) were calculated and

    Anna I. Ginzburg; Andrey G. Kostianoy; Nickolay A. Sheremet

    45

    Stability of hydrocarbons at deep Earth pressures and temperatures  

    PubMed Central

    Determining the thermochemical properties of hydrocarbons (HCs) at high pressure and temperature is a key step toward understanding carbon reservoirs and fluxes in the deep Earth. The stability of carbon-hydrogen systems at depths greater than a few thousand meters is poorly understood and the extent of abiogenic HCs in the Earth mantle remains controversial. We report ab initio molecular dynamics simulations and free energy calculations aimed at investigating the formation of higher HCs from dissociation of pure methane, and in the presence of carbon surfaces and transition metals, for pressures of 2 to 30 GPa and temperatures of 800 to 4,000 K. We show that for T?2,000 K and P?4 GPa HCs higher than methane are energetically favored. Our results indicate that higher HCs become more stable between 1,000 and 2,000 K and P?4 GPa. The interaction of methane with a transition metal facilitates the formation of these HCs in a range of temperature where otherwise pure methane would be metastable. Our results provide a unified interpretation of several recent experiments and a detailed microscopic model of methane dissociation and polymerization at high pressure and temperature.

    Spanu, Leonardo; Donadio, Davide; Hohl, Detlef; Schwegler, Eric; Galli, Giulia

    2011-01-01

    46

    Revised Estimate of Earth's Surface Heat Flow: 47 +- 2 TW  

    NASA Astrophysics Data System (ADS)

    Earth's surface heat flow provides a fundamental constraint on solid Earth dynamics. However, deriving an estimate of the total surface heat flux is complex, due to the inhomogeneous distribution of heat flow measurements and difficulties in measuring heat flux in young oceanic crust, arising due to hydrothermal circulation. A database of 38347 measurements (provided by G. Laske & G. Masters), representing a 55% increase on the number of measurements used previously, and the methods of Geographical Information Science (GIS), is used to derive a revised estimate of Earth's surface heat flux (Davies & Davies, 2010). To account for hydrothermal circulation in young oceanic crust, we use a model estimate of the heat flux, following the work of Jaupart et al., 2007; while for the rest of the globe, in an attempt to overcome the inhomogeneous distribution of measurements, we develop an average for different geological units. Two digital geology data sets are used to define the global geology: (i) continental geology - Hearn et al., 2003; and (ii) the global data-set of CCGM - Commission de la Carte Géologique du Monde, 2000. This leads to > 93,000 polygons defining Earth's geology. The influence of clustering is limited by intersecting the geology polygons with a 1 by 1 degree (at the equator) equal area grid. The average heat flow is evaluated for each geology class. The contribution of each geology class to the global surface heat flow is derived by multiplying this estimated average surface heat flux with the area of that geology class. The surface heat flow contributions of all the geology classes are summed. For Antarctica we use an estimate based on depth to Curie temperature and include a 1TW contribution from hot-spots in young ocean age. Geology classes with less than 50 readings are excluded. The raw data suggests that this method of correlating heat flux with geology has some power. Our revised estimate for Earth's global surface heat flux is 47 ± 2 TW, which is similar but slightly higher than previous estimates (e.g. Pollack et al., 1993 - 45 ± 1 TW; and Jaupart et al., 2007, - 46 ± 3 TW). It is difficult to reconcile such a high heat flow with estimates of internal heat sources in a monotonically cooling mantle. We will discuss alternative solutions and the extension of this work to produce a best estimate of the local heat flux globally.

    Davies, J. H.; Davies, D. R.

    2012-04-01

    47

    How Do Map Projections Distort Earth's Surface  

    NSDL National Science Digital Library

    Exploring Earth Investigations are Internet-based activities that use animations, interactive graphics, and unique imagery to help students gather information about a particular Earth science theme, issue, or concept.

    TERC (www.terc.edu)

    48

    Mudball: Surface dust and Snowball Earth deglaciation  

    NASA Astrophysics Data System (ADS)

    Recent modeling results have raised doubts about the ability to deglaciate from a global glaciation at atmospheric carbon dioxide levels that are realistic for a Neoproterozoic Snowball Earth. Here we argue that over the lifetime of a Snowball event, ice dynamics should lead to the development of a layer of continental and volcanic dust at the ice surface in the tropics that would significantly lower the tropical surface albedo and encourage deglaciation. This idea leads to the prediction that clay drapes found on top of Neoproterozoic glaciations should be thicker in tropical than extratropical regions. We test this idea by running the FOAM general circulation model (GCM) with an added tropical dust layer of different sizes and albedos and find that the tropical dust layer causes Snowball deglaciation at pCO2 = 0.01-0.1 bar in a reasonable regime of these parameters. We find similar, though more nuanced, results from a limited number of test cases using National Center for Atmospheric Research's CAM GCM.

    Abbot, Dorian S.; Pierrehumbert, Raymond T.

    2010-01-01

    49

    Local Sounding of the Earth Due to Interference of Electromagnetic Waves Near Earth's Surface  

    Microsoft Academic Search

    The theory of electromagnetic sounding of the earth, based on interference effects in the spatial structure of a pair of coupled waves, propagating along the earth's surface with the same frequency but different wavelengths, is proposed. A hitherto unknown heterogeneous structure of surface impedance, the conductivity being constant, is analysed by means of new exact analytical solutions of Maxwellian equations,

    A. B. Shvartsburg; M. A. Zuev

    1991-01-01

    50

    Plant transpiration and net entropy exchange on the Earth’s surface in a Czech watershed  

    Microsoft Academic Search

    The influence of plant transpiration on the entropy exchange was quantified as associated with the degradation of solar energy\\u000a on the Earth’s surface covered by plants. Two surfaces were studied: (1) productive surface — plant transpiration taken as\\u000a equal to the potential one, (2) non-productive surface — plant transpiration taken as equal to zero. The entropy exchanges\\u000a associated with the

    Miroslav Tesa?; ?ubomír Lichner; Jan ?ermák

    2007-01-01

    51

    The maximal runaway temperature of Earth-like planets  

    NASA Astrophysics Data System (ADS)

    In Simpson's (Simpson, G.C. [1927]. Mem. R. Meteorol. Soc. II (16), 69-95) classical derivation of the temperature of the Earth in the semi-gray model, the surface temperature diverges as the fourth root of the thermal radiation's optical depth. No resolution to this apparent paradox was yet obtained under the strict semi-gray approximation. Using this approximation and a simplified approach, we study the saturation of the runaway greenhouse effect. First we generalize the problem of the semi-gray model to cases in which a non-negligible fraction of the stellar radiation falls on the long-wavelength range, and/or that the planetary long-wavelength emission penetrates into the transparent short wavelength domain of the absorption. Second, applying the most general assumptions and independently of any particular properties of an absorber, we show that the greenhouse effect saturates and that any Earth-like planet has a maximal temperature which depends on the type of and distance to its main-sequence star, its albedo and the primary atmospheric components which determine the cutoff frequency below which the atmosphere is optically thick. For example, a hypothetical convection-less planet similar to Venus, that is optically thin in the visible, could have at most a surface temperature of 1200-1300 K irrespective of the nature of the greenhouse gas. We show that two primary mechanisms are responsible for the saturation of the runaway greenhouse effect, depending on the value of ?cut, the wavelength above which the atmosphere becomes optically thick. Unless ?cut is small and resides in the optical region, saturation is achieved by radiating the thermal flux of the planet through the short wavelength tail of the thermal distribution. This has an interesting observational implication, the radiation from such a planet should be skewed towards the NIR. Otherwise, saturation takes place by radiating through windows in the FIR.

    Shaviv, Nir J.; Shaviv, Giora; Wehrse, Rainer

    2011-12-01

    52

    Measurement of earth surface potential using scale model  

    Microsoft Academic Search

    Determination of the earth surface potential distribution due to discharging impulse current into grounding grids is difficult by using numerical methods. One way to measure the earth surface potential (ESP) and to study the transient performance of grounding grids subjected to impulse lightning current is using a scale model of the grounding grids with an electrolytic tank, because if all

    Sherif Ghoneim; Holger Hirsch; Ahdab Elmorshedy; Rabah Amer

    2007-01-01

    53

    UV 380 nm Reflectivity of the Earth's Surface.  

    National Technical Information Service (NTIS)

    The 380 nm radiance measurements of TOMS (Total Ozone Mapping Spectrometer) have been converted into a global data set of daily (1979 to 1992) Lambert equivalent reflectivities R of the Earth's surface and boundary layer (clouds, aerosols, surface haze, a...

    J. R. Herman E. Celarier D. Larko

    2000-01-01

    54

    The impacts of climate change on terrestrial Earth surface systems  

    NASA Astrophysics Data System (ADS)

    National and international policy initiatives have focused on reducing carbon emissions as a means by which to limit future climate warming. Much less attention has been paid by policymakers to monitoring, modelling and managing the impacts of climate change on the dynamics of Earth surface systems, including glaciers, rivers, mountains and coasts. This is a critical omission, however, as Earth surface systems provide water and soil resources, sustain ecosystem services and strongly influence biogeochemical climate feedbacks in ways that are as yet uncertain. We argue that there is a significant policy gap regarding the management of Earth surface systems' impacts under climate change that needs to be closed to facilitate the sustainability of cross-national Earth surface resource use. It is also a significant challenge to the scientific community to better understand Earth surface systems' sensitivity to climate forcing.

    Knight, Jasper; Harrison, Stephan

    2013-01-01

    55

    The international surface temperature initiative  

    NASA Astrophysics Data System (ADS)

    The aim of International Surface Temperature Initiative is to create an end-to-end process for analysis of air temperature data taken over the land surface of the Earth. The foundation of any analysis is the source data. Land surface air temperature records have traditionally been stored in local, organizational, national and international holdings, some of which have been available digitally but many of which are available solely on paper or as imaged files. Further, economic and geopolitical realities have often precluded open sharing of these data. The necessary first step therefore is to collate readily available holdings and augment these over time either through gaining access to previously unavailable digital data or through data rescue and digitization activities. Next, it must be recognized that these historical measurements were made primarily in support of real-time weather applications where timeliness and coverage are key. At almost every long-term station it is virtually certain that changes in instrumentation, siting or observing practices have occurred. Because none of the historical measures were made in a metrologically traceable manner there is no unambiguous way to retrieve the true climate evolution from the heterogeneous raw data holdings. Therefore it is desirable for multiple independent groups to produce adjusted data sets (so-called homogenized data) to adequately understand the data characteristics and estimate uncertainties. Then it is necessary to benchmark the performance of the contributed algorithms (equivalent to metrological software validation) through development of realistic benchmark datasets. In support of this, a series of successive benchmarking and assessment cycles are envisaged, allowing continual improvement while avoiding over-tuning of algorithms. Finally, a portal is proposed giving access to related data-products, utilizing the assessment results to provide guidance to end-users on which product is the most suited to their needs. Recognizing that the expertise of the metrological community has been under-utilized historically in such climate data analysis problems, the governance of the Initiative includes significant representation from the metrological community. We actively welcome contributions from interested parties to any relevant aspects of the Initiative work.

    Thorne, P. W.; Lawrimore, J. H.; Willett, K. M.; Allan, R.; Chandler, R. E.; Mhanda, A.; de Podesta, M.; Possolo, A.; Revadekar, J.; Rusticucci, M.; Stott, P. A.; Strouse, G. F.; Trewin, B.; Wang, X. L.; Yatagai, A.; Merchant, C.; Merlone, A.; Peterson, T. C.; Scott, E. M.

    2013-09-01

    56

    Temperature coefficients of rare earth permanent magnets  

    Microsoft Academic Search

    A new approach for calculating the temperature coefficients of magnetic parameters is proposed in order to more accurately describe high temperature characteristics of magnetic materials. Using this new approach, the “true” (or instantaneous) temperature coefficient of any magnetic parameter at a specific temperature can be determined and a plot of temperature coefficient vs. temperature can be obtained. This new type

    Sam Liu; G. Edward Kuhl

    1999-01-01

    57

    Rare Earth element yttrium's effect on high-temperature wear and friction performance of tin coating by the technique of ion plating on H13 steel surface  

    Microsoft Academic Search

    Using the technique of ion plating, TiN coating was prepared on H13 steel substrate and the high-temperature wear test was applied. The composition, phase structures and geometrical morphology of TiN serial-coatings were analyzed by use of SEM, XRD and 3D-topography instrument. As the transitional layer, the improvement effects of RE element yttrium on high temperature friction and wear behaviors of

    Xianping Sun; Lijun Wei; Yao Huang; Leigang Wang

    2010-01-01

    58

    IN SITU HIGH TEMPERATURE PHASE TRANSFORMATIONS IN RARE EARTH NIOBATES  

    Microsoft Academic Search

    Rare earth niobates present an interesting group of materials due to their reversible ferroelastic to paraelastic phase transformation. So far these phase transformations have mainly been studied either at low temperatures (for instance in LaNbO4) or in specimen that have been quenched after heat treatment. Here, high temperature phase transformations of rare earth niobates have been studied in-situ using synchrotron

    K. Jurkschat; P. Sarin; L. F. Siah; W. M. Kriven

    59

    Earthing: health implications of reconnecting the human body to the Earth's surface electrons.  

    PubMed

    Environmental medicine generally addresses environmental factors with a negative impact on human health. However, emerging scientific research has revealed a surprisingly positive and overlooked environmental factor on health: direct physical contact with the vast supply of electrons on the surface of the Earth. Modern lifestyle separates humans from such contact. The research suggests that this disconnect may be a major contributor to physiological dysfunction and unwellness. Reconnection with the Earth's electrons has been found to promote intriguing physiological changes and subjective reports of well-being. Earthing (or grounding) refers to the discovery of benefits-including better sleep and reduced pain-from walking barefoot outside or sitting, working, or sleeping indoors connected to conductive systems that transfer the Earth's electrons from the ground into the body. This paper reviews the earthing research and the potential of earthing as a simple and easily accessed global modality of significant clinical importance. PMID:22291721

    Chevalier, Gaétan; Sinatra, Stephen T; Oschman, James L; Sokal, Karol; Sokal, Pawel

    2012-01-12

    60

    Earthing: Health Implications of Reconnecting the Human Body to the Earth's Surface Electrons  

    PubMed Central

    Environmental medicine generally addresses environmental factors with a negative impact on human health. However, emerging scientific research has revealed a surprisingly positive and overlooked environmental factor on health: direct physical contact with the vast supply of electrons on the surface of the Earth. Modern lifestyle separates humans from such contact. The research suggests that this disconnect may be a major contributor to physiological dysfunction and unwellness. Reconnection with the Earth's electrons has been found to promote intriguing physiological changes and subjective reports of well-being. Earthing (or grounding) refers to the discovery of benefits—including better sleep and reduced pain—from walking barefoot outside or sitting, working, or sleeping indoors connected to conductive systems that transfer the Earth's electrons from the ground into the body. This paper reviews the earthing research and the potential of earthing as a simple and easily accessed global modality of significant clinical importance.

    Chevalier, Gaetan; Sinatra, Stephen T.; Oschman, James L.; Sokal, Karol; Sokal, Pawel

    2012-01-01

    61

    Intercomparison of the seasonal cycle of Titan's and Earth's surface climatology  

    NASA Astrophysics Data System (ADS)

    The characteristics of the seasonal cycle of Titan's surface temperature, surface pressure and surface wind and their implication for weather are compared with the terrestrial counterpart. The surface climatology of Titan predicted by a GCM and partly observed by Cassini is presented side by side with the well-known Earth's climatology. Even though the surface temperature varies only by a few K in the course of a Titan year, the seasonality of Titan's surface climate is partly more pronounced than on Earth in a qualitative sense. The seasonal forcing can completely reverse the global circulation and precipitation pattern on almost entire Titan in a monsoon-like fashion. This high sensitivity of Titan's climate to small seasonal temperature variations can be mainly ascribed to Titan's slow rotation.

    Tokano, T.

    2012-09-01

    62

    Profiling Earth's Surface using GeoMapApp  

    NSDL National Science Digital Library

    In this exercise, students relate large-scale features on Earth's surface to lithospheric plates, the underlying asthenosphere, earthquakes, and volcanoes. After creating a cross section showing elevation using GeoMapApp, students add additional features by hand.

    Wetzel, Laura

    63

    GPS Aircraft Receiver Earth-Surface Multipath Reception  

    Microsoft Academic Search

    DC-3 Flight test over Middle Bass Island, Lake Erie (left) to measure earth-surface induced multipath using both top-mounted and bottom-mounted (right) GPS antennas. For aircraft precision approach operations, earth-surface multipath as observed by a top- mounted aircraft GPS antenna degrades the accuracy of the pseudorange measurement. Of particular concern are stabilized approaches over water where the water reflection of the

    Frank van Graas

    64

    Valence state at the surface of rare-earth metals  

    Microsoft Academic Search

    The valence state of a rare-earth metal surface is investigated by using general properties of the surface tension of metals. Thereby it is concluded that samarium is likely to have a divalent or partly divalent surface on top of its trivalent bulk phase, which agrees with recent spectroscopic observations. Also californium metal is discussed from this point of view. Finally,

    Börje Johansson

    1979-01-01

    65

    The equilibrium sensitivity of the Earth's temperature to radiation changes  

    Microsoft Academic Search

    The Earth's climate is changing rapidly as a result of anthropogenic carbon emissions, and damaging impacts are expected to increase with warming. To prevent these and limit long-term global surface warming to, for example, 2 °C, a level of stabilization or of peak atmospheric CO2 concentrations needs to be set. Climate sensitivity, the global equilibrium surface warming after a doubling

    Reto Knutti; Gabriele C. Hegerl

    2008-01-01

    66

    Improving satellite antenna temperature estimation by high-resolution emission model of the Earth  

    Microsoft Academic Search

    This paper describes the results of a study aimed at accurately determining the antenna noise temperature used to calculate the uplink G\\/T for satellite-borne receivers. The antenna noise temperature is calculated from a brightness temperature database of the Earth which, for each surface pixel (1°×1°), includes the effects of the season, observation angle and frequency. Good correlation has been found

    G. Schiavon; P. Ferraxxoli; L. Guerriero; R. Jorgensen; S. Badessi; P. De Maagt; H. Fenech

    1999-01-01

    67

    30 CFR 717.15 - Disposal of excess rock and earth materials on surface areas.  

    Code of Federal Regulations, 2010 CFR

    ... false Disposal of excess rock and earth materials on surface areas. 717.15 Section 717.15 Mineral...717.15 Disposal of excess rock and earth materials on surface areas. Excess rock and earth materials produced from an...

    2009-07-01

    68

    30 CFR 717.15 - Disposal of excess rock and earth materials on surface areas.  

    Code of Federal Regulations, 2010 CFR

    ... false Disposal of excess rock and earth materials on surface areas. 717.15 Section 717.15 Mineral...717.15 Disposal of excess rock and earth materials on surface areas. Excess rock and earth materials produced from an...

    2010-07-01

    69

    Solar and geomagnetic activity, extremely low frequency magnetic and electric fields and human health at the Earth’s surface  

    Microsoft Academic Search

    The possibility that conditions on the Sun and in the Earth’s magnetosphere can affect human health at the Earth’s surface has been debated for many decades. This work reviews the research undertaken in the field of heliobiology, focusing on the effect of variations of geomagnetic activity on human cardiovascular health. Data from previous research are analysed for their statistical significance,

    S. J. Palmer; M. J. Rycroft; M. Cermack

    2006-01-01

    70

    The energy balance of the earth' surface : a practical approach  

    Microsoft Academic Search

    This study is devoted to the energy balance of the earth's surface with a special emphasis on practical applications. A simple picture of the energy exchange processes that take place at the ground is the following. Per unit time and area an amount of radiant energy is supplied to the surface. This radiation originates partly from the sun, but an~

    Bruin de H. A. R

    1982-01-01

    71

    Isotope fractionation in surface ionization ion source of alkaline-earth iodides  

    SciTech Connect

    The relationship between the isotope fractionation of alkaline-earth elements in the surface ionization ion source and the evaporation filament current, i.e., filament temperature, was studied. It was confirmed that the isotope fractionation depends on the evaporation filament temperature; the isotope fractionation in the case of higher temperature of filament becomes larger. The ionization and evaporation process in the surface ionization ion source was discussed, and it was concluded that the isotope fractionation is suppressed by setting at the lower temperature of evaporation filament because the dissociations are inhibited on the evaporation filament.

    Suzuki, T.; Kanzaki, C.; Nomura, M.; Fujii, Y. [Research Laboratory for Nuclear Reactors, Tokyo Institute of Technology, O-okayama, Meguro-ku, Tokyo 152-8550 (Japan)

    2012-02-15

    72

    Using Vegetation, Precipitation, and Surface Temperature to Study Climate Zones  

    NSDL National Science Digital Library

    The type of climate present in a particular location depends on several variables, including surface temperature and annual precipitation. One indicator of a locale' s climate is the vegetation present, a relationship used by the Koeppen system of climate classification. Using a microset of satellite data to investigate vegetation of a particular climate zone, students will identify factors that influence an area's climate. They will explore the relationship between amount of vegetation, precipitation, and surface temperature to study Earth's climate zones.

    73

    Thermal Conductivity of Earth Materials at High Temperatures  

    Microsoft Academic Search

    The total thermal conductivity (lattice plus radiative) of several important earth materials is measured in the temperature range 500ø-1900øK. A new technique is used in which a CO. laser generates a low-frequency temperature wave at one face of a small disk-shaped sample, and an infrared detector views the opposite face to detect the phase of the emerging radiation. Phase data

    John F. Schatz; Gene Simmons

    1972-01-01

    74

    Solar flare intermittency and the earth's temperature anomalies.  

    PubMed

    We argue that Earth's short-term temperature anomalies and the solar flare intermittency are linked. The analysis is based upon the study of the scaling of both the spreading and the entropy of the diffusion generated by the fluctuations of the temperature time series. The joint use of these two methods evidences the presence of a Lévy component in the temporal persistence of the temperature data sets that corresponds to the one that would be induced by the solar flare intermittency. The mean monthly temperature data sets cover the period from 1856 to 2002. PMID:12857233

    Scafetta, Nicola; West, Bruce J

    2003-06-17

    75

    Gas-Surface Interactions in Low-Earth Orbit  

    NASA Astrophysics Data System (ADS)

    When the space age began, some aerodynamicists expected that the surfaces of spacecraft would be cleaned by desorption in the high vacuum of space; while others, familiar with experiments on engineering surfaces, believed that satellite surfaces would be contaminated. During subsequent decades, satellite evidence has accumulated, showing that surfaces in low-Earth orbit are contaminated by adsorbed atomic oxygen and its reaction products. These contaminants cause accommodation coefficients to be high, and the angular distribution of reemitted molecules to be nearly diffuse. These surface conditions must be considered in calculating satellite drag coefficients in free-molecular flow. We describe the experimental and theoretical developments which have led to these conclusions.

    Moe, Kenneth; Moe, Mildred M.

    2011-05-01

    76

    High-Temperature Surface Sealant  

    Microsoft Academic Search

    Hot-Kote 2200 is a ready-to-use, high solids product formulated for lockdown of high temperature substrates. Hot-Kote 2200 should be applied on surfaces after asbestos insulation has been removed. The completely inorganic ceramic formulation prevents Hot-Kote 2200 from \\

    Hot Kote

    2000-01-01

    77

    Volcanic effects on surface temperatures  

    Microsoft Academic Search

    It is usually difficult to demonstrate the effects on surface temperatures of the injection of gases and dust particles from a volcanic eruption. In a study of major 19th- and 20th-century volcanic eruptions, and climate record for the same period, S. Self, M. Rampino, and J. Barbera report convincing evidence of at least minor effects. They compared the record of

    Peter M. Bell

    1982-01-01

    78

    On the Concentration of Certain Elements at the Earth's Surface  

    Microsoft Academic Search

    A survey of the abundances of elements in the ocean and sedimentary rocks as compared to their abundances in the weathered igneous rocks shows that carbon, nitrogen, oxygen as water, chlorine, bromine and boron are highly concentrated in the surface materials and that thicknesses of from 17 to 89 km of the outer part of the earth would be required

    H. C. Urey

    1953-01-01

    79

    Surface of Near-Earth Asteroids (Abstract Only).  

    National Technical Information Service (NTIS)

    The surfaces of near-Earth asteroids are expected to differ significantly from those of large objects like the moon because of their different origin and evolution. A selection of such objects for an extensive procurement of material will also be made on ...

    M. Hoffmann

    1991-01-01

    80

    Radar Polarimetric Studies of Near-Earth Asteroid Surface Properties  

    Microsoft Academic Search

    We use a radar polarimetric technique to study the surface physical properties of a small sample of Near Earth Asteroids (NEAs), to search for evidence of regolith cover, and to correlate the radar polarimetric properties with size and shape. In radar experiments, an analysis of the degree of linear polarization in the received echo can be used to investigate whether

    Lynn M. Carter; D. B. Campbell; M. C. Nolan

    2007-01-01

    81

    Area of Earth's Surface Visible at any Altitude  

    Microsoft Academic Search

    IN these days of aviators and of record heights attained by them, perhaps the following rule to find the area of the earth's surface visible from a given height may be of interest. The rule depends upon the fact that if the height above a sphere is th part of the sphere's diameter, then the area visible from this height

    W. Moss

    1913-01-01

    82

    Surface waves on periodic horizontal structures over a flat earth  

    Microsoft Academic Search

    An analytic theory is presented for the surface waves supported by three types of transmission lines: a Goubau line (C-line), a coaxial line with periodic 360 deg circumferential slots (C-line) and a coaxial line with periodic partial circumferential slots (R-line), in free space as well as in the presence of a lossy flat earth. The theory for the surface waves

    H. B. Tran

    1978-01-01

    83

    Surface Temperature and Soil Temperature Protocols; Observations, Partnerships, Science  

    Microsoft Academic Search

    As NSF funded GLOBE scientists, we have engaged students and teachers in the surface temperature and soil temperature protocols. In 2002, we started to develop the surface temperature protocol and finalized it in the spring 2005 for the GLOBE Teacher's Guide. Surface temperature is the temperature of sidewalks, parking lots, leaves, grass, bare ground, etc. as determined by the electromagnetic

    K. P. Czajkowski; A. Spongberg; T. Benko; J. Witter; T. Ault; T. Peterson

    2005-01-01

    84

    External Resource: Surface Air Temperature Trends of the Caribbean  

    NSDL National Science Digital Library

    This activity allows learners/students to use real satellite data to determine the changes in near-surface air temperature at different times of the year over the Caribbean Sea. Upon completion of the activity, learners should be able to state how Earth's

    1900-01-01

    85

    Surface reactions on rare earth metals monitored by work function measurements  

    SciTech Connect

    Surface reactions on clean, oxidized, and partially hydrided rare earth metal films with O/sub 2/, H/sub 2/, H/sub 2/O, CO, and CO/sub 2/ were monitored by dynamic work function measurements under ultrahigh vacuum conditions. The work function data are discussed in the light of electron spectroscopic evidence, where available. The main results of this study are: Initial oxidation of Yb seems to follow a different oxidation mechanism as compared to other rare earth metals. Reaction of H/sub 2/O with clean oxidized, and hydrided rare earth metal surfaces yields surface hydroxyl species. H/sub 2/ uptake on divalent Yb metal is much slower than on trivalent Er metal, but occurs at a comparable rate on the oxidized systems. On oxidized surfaces, surface OH formation is substantiated for room-temperature reaction with H/sub 2/. The ..delta.. phi data indicate high reactivity of CO and CO/sub 2/ toward clean rare earth metal surfaces and are consistent with dissociative adsorption of both molecules.

    Strasser, G.; Bertel, E.; Netzer, F.P.

    1983-02-01

    86

    Temperature-dependent Sellmeier equations for rare-earth sesquioxides.  

    PubMed

    High-power lasers are making increasing demands on laser hosts especially in the area of thermal management. Traditional hosts, such as YAG, are unsuitable for many high-power applications and therefore, new hosts are being developed including rare-earth sesquioxides. We report new measurements of the refractive indices of these materials as functions of wavelength and temperature, which will aid in the design of laser cavities and other nonlinear optical elements. PMID:23736339

    Zelmon, David E; Northridge, Jessica M; Haynes, Nicholas D; Perlov, Dan; Petermann, Klaus

    2013-06-01

    87

    Metallic rare-earth silicide nanowires on silicon surfaces.  

    PubMed

    The formation, atomic structure, and electronic properties of self-assembled rare-earth silicide nanowires on silicon surfaces were studied by scanning tunneling microscopy and angle-resolved photoelectron spectroscopy. Metallic dysprosium and erbium silicide nanowires were observed on both the Si(001) and Si(557) surfaces. It was found that they consist of hexagonal rare-earth disilicides for both surface orientations. On Si(001), the nanowires are characterized by a one-dimensional band structure, while the electronic dispersion is two-dimensional for the nanowires formed on Si(557). This behavior is explained by the different orientations of the hexagonal c axis of the silicide leading to different conditions for the carrier confinement. By considering this carrier confinement it is demonstrated how the one-dimensional band structure of the nanowires on Si(001) can be derived from the two-dimensional one of the silicide monolayer on Si(111). PMID:23221358

    Dähne, Mario; Wanke, Martina

    2012-12-05

    88

    Statistics of free surface flow through stochastic earth dam  

    SciTech Connect

    Even though soil is a highly variable material, the analysis of flow through earth dams typically proceeds deterministically and results can sometimes be quite misleading. In fact it is well known that soil permeability varies randomly from point to point in space and an improved earth dam model should incorporate this variability. In this paper the soil permeability in an earth dam of variable geometry is viewed as a weakly stationary spatially random field following a lognormal distribution with prescribed mean, variance, and spatial correlation structure. The mean and variance of the total flow rate through the dam and free surface drawdown are estimated using Monte Carlo simulations. A simplified empirical approach to the prediction of the mean and variance of the flow rate is presented to allow these quantities to be approximated easily and without resorting to simulation.

    Fenton, G.A. [Technical Univ. of Nova Scotia, Halifax, Nova Scotia (Canada). Dept. of Applied Mathematics; Griffiths, D.V. [Colorado School of Mines, Golden, CO (United States)

    1996-06-01

    89

    Electric and Magnetic Fields at the Earth's Surface Due to Auroral Currents  

    Microsoft Academic Search

    The horizontal components of the electric and magnetic fields due to auroral atmospheric currents are calculated at the surface of the earth. For sinusoidal changes in the earth's magnetic field (Fourier frequency components of actual nonsinusoidal variations), a lower limit of the corresponding earth-surface potential is obtained by considering a line-type auroral current over a nonuniform stratified earth. An upper

    VERNON D. ALBERTSON; JOHAN A. VAN BAELEN

    1970-01-01

    90

    Spaced button thrust surface for earth boring bit  

    SciTech Connect

    An earth boring bit has thrust surfaces with enhanced cooling features. The bit has a body with three depending bearing pins. A cutter having an axial cavity is mounted on each bearing pin. The bearing pin and the cavity have one or more mating thrust surfaces that are perpendicular to the axis of the bearing pin. These thrust surfaces absorb outward forces that the cutter imposes on the bearing pin. At least one of the thrust surfaces consists of a series of tungsten carbide buttons spaced in a circular array. These buttons have flat ends for engaging the opposite thrust surfaces. The buttons protrude from the supporting metal, allowing cooling fluid to be circulated past to cool the thrust surfaces.

    Shepherd, W.L.

    1984-05-29

    91

    Surface Wave Propagation Around the Earth: A Problem Solving Exercise  

    NSDL National Science Digital Library

    In this activity, students examine a seismogram display called a seismic record section in which each trace is a seismogram recorded at a specific seismograph station. The seismograms are plotted according to the distance (in degrees, geocentric angle) from the earthquake location and time from the earthquake origin. The traces are of the vertical component of ground motion, and have been filtered to include only periods longer than 125 seconds. Students look for the prominent arrivals, called phases, that angle across the record section and are labeled and discover that they are called long-period Rayleigh waves. Students learn that these waves travel along the surface of the Earth and that surface waves penetrate (have particle motion) to depths of tens to hundreds of km but travel approximately parallel to the Earth's surface. Since the surface waves propagate in all directions from the source, the arrival times are approximately the same as if the stations were all located along a great circle path from the epicenter. From this, students are able to measure the distance traveled and calculate the velocity in kilometers per second and how long it takes for the wave to go around the Earth.

    Braile, Larry

    92

    Earth surface reflectance climatology from 3 years of OMI data  

    Microsoft Academic Search

    Global maps of the Earth's surface Lambertian equivalent reflectance (LER) are constructed using 3 years of Ozone Monitoring Instrument (OMI) measurements obtained between October 2004 and October 2007 at 23 wavelengths between 328 and 500 nm. The maps are constructed on a 0.5° by 0.5° longitude-latitude grid for each calendar month using an algorithm based on temporal histograms of the

    Q. L. Kleipool; M. R. Dobber; J. F. de Haan; P. F. Levelt

    2008-01-01

    93

    Opposed button thrust surfaces for earth boring bits  

    SciTech Connect

    An earth boring bit has thrust surfaces with enhanced cooling features. The bit has a body with three depending bearing pins. A cutter having an axial cavity is mounted on each bearing pin. The bearing pin and the cavity have mating thrust shoulders. Hard metal inserts or buttons are spaced around each of the shoulders and secured interferingly in mating holes. The buttons in one of the shoulders protrude slightly from the shoulder to allow air to flow past.

    Mullins, J. M.

    1985-10-29

    94

    Temperature Measurement on Shocked Surfaces  

    SciTech Connect

    We have used a two-stage gas gun to address issues relating to the accurate determination of the temperature of a shocked metal surface at a metal/LiF interface. We have investigated the light flash generated by the dynamics at the interface, the light sources at the LiF boundary that can contaminate the emission from the metal surface, and the light emitted from defects in the LiF crystal as it is being shocked. A seven-channel spectrometer with fiber-optic transmission of light from the target was used, and a Hohlraum geometry was used to increase the effective emissivity of the target. The method that yielded the best results is described and is expected to be useful for a wide range of applications.

    Poulseu, P.; Baum, D.; Fiske, P.; Holtkamp, D.

    2000-08-08

    95

    Current Tropical Sea Surface Temperatures  

    NSDL National Science Digital Library

    This animation shows the most recent Sea Surface Temperature (SST) data available for the Gulf of Mexico and the Atlantic Coast region. Users can see the progression of warm waters (shown in yellow, orange, and red) slowly filling the Gulf of Mexico. This natural annual warming contributes to the possible formation of hurricanes in the Gulf. The animation updates every 24 hours, and still images of the data are also available. There is also imagery of the most recent 10-day average of SST anomalies in the Pacific Ocean, which is used by scientists for studying El Nino and La Nina. Warmer colors (yellow, red, orange) indicate positive anomalies (temperatures above normal). The imagery is from the Advanced Microwave Scanning Radiometer for EOS (AMSR-E) aboard the National Aeronautics and Space Administration's (NASA) Aqua satellite.

    96

    The Pacific sea surface temperature  

    NASA Astrophysics Data System (ADS)

    The Pacific sea surface temperature data contains two components: N, a signal that exhibits the familiar El Niño/La Niña phenomenon and N, a signal of one-year period. Analysis reveals: (1) The existence of an annual solar forcing F; (2) N is phase locked directly to F while N is frequently phase locked to the 2nd or 3rd subharmonic of F. At least ten distinct subharmonic time segments of N since 1870 are found. The beginning or end dates of these segments have a near one-to-one correspondence with the abrupt climate changes previously reported. Limited predictability is possible.

    Douglass, David H.

    2011-12-01

    97

    Earth encounters as the origin of fresh surfaces on near-Earth asteroids  

    NASA Astrophysics Data System (ADS)

    Telescopic measurements of asteroids' colours rarely match laboratory reflectance spectra of meteorites owing to a `space weathering' process that rapidly reddens asteroid surfaces in less than 106 years. `Unweathered' asteroids (those having spectra matching the most commonly falling ordinary chondrite meteorites), however, are seen among small bodies the orbits of which cross inside Mars and the Earth. Various explanations have been proposed for the origin of these fresh surface colours, ranging from collisions to planetary encounters. Less reddened asteroids seem to cross most deeply into the terrestrial planet region, strengthening the evidence for the planetary-encounter theory, but encounter details within 106 years remain to be shown. Here we report that asteroids displaying unweathered spectra (so-called `Q-types') have experienced orbital intersections closer than the Earth-Moon distance within the past 5×105 years. These Q-type asteroids are not currently found among asteroids showing no evidence of recent close planetary encounters. Our results substantiate previous work: tidal stress, strong enough to disturb and expose unweathered surface grains, is the most likely dominant short-term asteroid resurfacing process. Although the seismology details are yet to be worked out, the identification of rapid physical processes that can produce both fresh and weathered asteroid surfaces resolves the decades-long puzzle of the difference in colour of asteroids and meteorites.

    Binzel, Richard P.; Morbidelli, Alessandro; Merouane, Sihane; DeMeo, Francesca E.; Birlan, Mirel; Vernazza, Pierre; Thomas, Cristina A.; Rivkin, Andrew S.; Bus, Schelte J.; Tokunaga, Alan T.

    2010-01-01

    98

    Earth encounters as the origin of fresh surfaces on near-Earth asteroids.  

    PubMed

    Telescopic measurements of asteroids' colours rarely match laboratory reflectance spectra of meteorites owing to a 'space weathering' process that rapidly reddens asteroid surfaces in less than 10(6) years. 'Unweathered' asteroids (those having spectra matching the most commonly falling ordinary chondrite meteorites), however, are seen among small bodies the orbits of which cross inside Mars and the Earth. Various explanations have been proposed for the origin of these fresh surface colours, ranging from collisions to planetary encounters. Less reddened asteroids seem to cross most deeply into the terrestrial planet region, strengthening the evidence for the planetary-encounter theory, but encounter details within 10(6) years remain to be shown. Here we report that asteroids displaying unweathered spectra (so-called 'Q-types') have experienced orbital intersections closer than the Earth-Moon distance within the past 5 x 10(5) years. These Q-type asteroids are not currently found among asteroids showing no evidence of recent close planetary encounters. Our results substantiate previous work: tidal stress, strong enough to disturb and expose unweathered surface grains, is the most likely dominant short-term asteroid resurfacing process. Although the seismology details are yet to be worked out, the identification of rapid physical processes that can produce both fresh and weathered asteroid surfaces resolves the decades-long puzzle of the difference in colour of asteroids and meteorites. PMID:20090748

    Binzel, Richard P; Morbidelli, Alessandro; Merouane, Sihane; Demeo, Francesca E; Birlan, Mirel; Vernazza, Pierre; Thomas, Cristina A; Rivkin, Andrew S; Bus, Schelte J; Tokunaga, Alan T

    2010-01-21

    99

    Sea Surface Temperatures (SST): Significance and Measurement  

    NASA Astrophysics Data System (ADS)

    Oceans cover 71 percent of Earth's surface and control the global climate. Quoted global mean temperature values and trends, largely based on land thermometers, differ substantially -" mainly because of uncertainties about SST. The ongoing controversy about the relative importance of natural climate changes and Anthropogenic Global Warming (AGW) revolves mainly around disparities between temperature trends of the atmosphere and surface (in the tropics and SH, i.e. mostly SST). Accurate measurement of SST is difficult. Geographic coverage is poor and there are many different techniques, each with its own problems and uncertainties: Water temperatures from buckets and ship-engine inlets; fixed and floating buoys; air temperatures from shipboard and island stations; and remote sensing from satellites using IR and microwaves. As is evident, each technique refers to a different level below the air-water interface. Drifter buoys (at around 50 cm) measure temperatures in the euphotic layers that are generally warmer than the bulk mixed layer sampled by ships (typically around 10 m). The IR emission arises from a 10-micron-thick skin that interacts dynamically with the underlying "mixed layer." The microwave data depend also on emissivity and therefore on surface roughness and sea state. SST data derived from corals provide some support for instrumental data but are not conclusive. The majority of corals show a warming trend since 1979; others show cooling or are ambiguous. There are different ways of interpreting this result. Physical optics dictates that the downwelling IR radiation from atmospheric greenhouse gases is absorbed in the first instance within the skin. Only direct measurements can establish how much of this energy is shared with the bulk mixed layer (to which the usual SST values refer.). SST controls evaporation and therefore global precipitation. SST influences tropical cyclones and sea-level rise; but there is lively debate on those issues. Changes in SST are also responsible for changes in deep- ocean temperatures and ocean heat storage. But recent claims that an increase in heat storage is a "smoking gun" for AGW are without merit.

    Singer, S. F.

    2006-05-01

    100

    Solar turbulence in earth's global and regional temperature anomalies.  

    PubMed

    This paper presents a study of the influence of solar activity on the earth's temperature. In particular, we focus on the repercussion of the fluctuations of the solar irradiance on the temperature of the Northern and Southern hemispheres as well as on land and ocean regions. While solar irradiance data are not directly analyzed, we make use of a published solar irradiance reconstruction for long-time-scale fluctuations, and for short-time-scale fluctuations we hypothesize that solar irradiance and solar flare intermittency are coupled in such a way that the solar flare frequency fluctuations are stochastically equivalent to those of the solar irradiance. The analysis is based upon wavelet multiresolution techniques and scaling analysis methods for processing time series. The limitations of the correlation analysis applied to the short-time-scale fluctuations are discussed. The scaling analysis uses both the standard deviation and the entropy of the diffusion generated by the temperature signals. The joint use of these two scaling methods yields evidence of a Lévy component in the temporal persistence of the temperature fluctuations within the temporal range from a few weeks to a few years. This apparent Lévy persistence of the temperature fluctuations is found, by using an appropriate model, to be equivalent to the Lévy scaling of the solar flare intermittency. The mean monthly temperature data sets cover the period from 1856 to 2002. PMID:14995555

    Scafetta, Nicola; Grigolini, Paolo; Imholt, Timothy; Roberts, Jim; West, Bruce J

    2004-02-26

    101

    Molecular dynamics calculation of liquid iron properties and adiabatic temperature gradient in the Earth's outer core  

    Microsoft Academic Search

    The knowledge of the temperature radial distribution in the Earth's core is important to understand the heat balance and conditions in the Earth's interior. Molecular dynamics (MD) simulations were applied to study the properties of liquid iron under the pressure-temperature conditions of the Earth's outer core. It is shown that the model used for the MD simulations can reproduce recent

    L. Koci; A. B. Belonoshko; R. Ahuja

    2007-01-01

    102

    New surface temperature analyses for climate monitoring  

    Microsoft Academic Search

    Global surface temperature is a critical measure of climate variation. Here the averages of a new surface-temperature analysis are compared to an estimate of the global average which has been used for monitoring surface-temperature variations at NOAA's National Climatic Data Center (NCDC) since 1998. As a replacement to the existing method, this new analysis uses improved methods that provide error

    Thomas M. Smith; Thomas C. Peterson; Jay H. Lawrimore; Richard W. Reynolds

    2005-01-01

    103

    Remote sensing of the Dead Sea surface temperature  

    NASA Astrophysics Data System (ADS)

    The Dead Sea is a unique terminal lake located at the lowest place on Earth's surface. It has the highest surface temperature, salinity, and density among Earth's large water bodies, and its level is currently dropping at a rate of ˜1 m/a. Knowledge of the Dead Sea thermal and saline structure is based on meteorological and hydrological measurements from a single site at a time. In this study, we used satellite and in situ data to characterize the spatial and temporal variations of the Dead Sea sea surface temperature (SST) and to explore the causes for these variations. Sequences of almost continuous individual satellite images were transformed into a time series of parameters representing the spatial distribution of SST. Also used were in situ measured bulk SST, wind speed, solar radiation, and water temperature profiles with depth. Analysis of this data set shows strong diurnal and seasonal variations of the surface and vertical temperature field and the meteorological forcing. The temperature field is heterogeneous after noon, when radiation is high and wind speed is low and thermal layering develops. The temperature field is homogeneous during the nighttime, when solar radiation is absent and the high wind speed vertically mixes the upper layer.

    Nehorai, R.; Lensky, I. M.; Lensky, N. G.; Shiff, S.

    2009-05-01

    104

    COMPARISON OF LAND SURFACE EMISSIVITY AND RADIOMETRIC TEMPERATURE DERIVED FROM MODIS AND ASTER SENSORS  

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study compares surface emissivity and radiometric temperature products derived using data collected with the MODerate resolution Imaging Spectroradiometer (MODIS) and Advanced Spaceborne Thermal Emission Reflectance Radiometer (ASTER) sensors, on the Earth Observation System (EOS) - Terra satel...

    105

    Transport of radon and thoron at the earth's surface  

    SciTech Connect

    This report covers progress under the current funding period Jan. 1, 1991 to Jan. 1, 1992 and presents the continuation proposal for Jan. 1, 1992 to Jan. 1, 1993. The previous progress report was submitted in May 1990, so activities during the last half of 1990 will also be included. Major activities over the last year have centered on the study of disequilibrium of radon progeny near the earth's surface and the sources of thoron in indoor air. In addition, we have carried out supplemental measurements of radon sorption coefficients in porous materials focusing on the physical mechanism of sorption.

    Schery, S.D.

    1991-06-15

    106

    Displacements of the earth's surface due to atmospheric loading - Effects of gravity and baseline measurements  

    Microsoft Academic Search

    Atmospheric mass loads and deforms the earth's crust. By performing a convolution sum between daily, global barometric pressure data and mass loading Green's functions, the time dependent effects of atmospheric loading, including those associated with short-term synoptic storms, on surface point positioning measurements and surface gravity observations are estimated. The response for both an oceanless earth and an earth with

    T. M. van Dam; J. M. Wahr

    1987-01-01

    107

    Modeling novel isotopic proxies of the oxygenation of the earth's surface  

    Microsoft Academic Search

    Tracking the evolution of the oxidation state of the Earth's surface environment has increased understanding of the biological, atmospheric, oceanic, and geological evolution of the Earth, and may allow us to broaden the search for life on extrasolar planets. In this thesis, two relatively new proxies for the evolution of the Earth's surface oxidation state are examined. Both proxies use

    Shawn D. Domagal-Goldman

    2007-01-01

    108

    Estimation of small ion concentration near the Earth's surface  

    NASA Astrophysics Data System (ADS)

    Atmospheric ions produced by radon gas exhalation from the Earth’s surface can play a vital role in the electrification of atmosphere, especially during nights when the gases are trapped in a stable layer close to the surface. The measurements of concentration of radon and its progeny, air conductivity and aerosol size distribution made at Pune, India, have been analyzed. The concentrations of radon and its progeny show maxima during night and early morning hours, between 0500 and 0700 IST when atmosphere is more stable and mixing is low and start decreasing after sunrise and attain minima during 1000-1800 h when air is unstable. The diurnal variation of the ionization rate, calculated using the concentrations of radon and its progeny, follows the variations of concentrations of radon and its progeny. The ion-aerosol balance equations are solved to study the effect of aerosols on small ion concentration in the lower atmosphere. It has been found that during daytime when aerosol concentration is high, 20-30% reduction in small ion concentration can occur due to aerosols. The small ion concentration estimated using measured air conductivity is compared with small ion concentration estimated by solving ion-aerosol balance equations and both are found to be in good agreement with each other.

    Kamsali, Nagaraja; Pawar, S. D.; Murugavel, P.; Gopalakrishnan, V.

    2011-10-01

    109

    Terrestrial manganese-53 — A new monitor of Earth surface processes  

    NASA Astrophysics Data System (ADS)

    We report the first systematic study of the terrestrial cosmogenic radionuclide manganese-53 ( T1/2 = 3.7 Ma) measured in thirteen samples from nine dolerite surfaces in the Dry Valleys, Antarctica. The terrestrial manganese-53 concentrations correlate well with cosmic-ray-produced helium-3 and neon-21 concentrations in the same samples, implying that the manganese-53 is produced continuously in situ and retained quantitatively over millions of years. The terrestrial manganese-53 production rate determination normalized to iron (the only important target element) and to high-latitude and sealevel yields a value of P53 = 103 ± 11 atoms yr - 1 (g Fe) - 1 . This is consistent with the theoretical value of 120 ± 18 atoms yr - 1 (g Fe) - 1 obtained from modeling calculations. Our results show that the manganese-53 concentrations in bulk terrestrial rocks can be used to monitor Earth surface processes on time-scales exceeding 10 My.

    Schaefer, Joerg M.; Faestermann, Thomas; Herzog, Gregory F.; Knie, Klaus; Korschinek, Gunther; Masarik, Jozef; Meier, Astrid; Poutivtsev, Michail; Rugel, Georg; Schlüchter, Christian; Serifiddin, Feride; Winckler, Gisela

    2006-11-01

    110

    High temperature heat pipe experiments in low earth orbit  

    SciTech Connect

    Although high temperature, liquid metal heat pipe radiators have become a standard component on most high power space power system designs, there is no experimental data on the operation of these heat pipes in a zero gravity or micro-gravity environment. Experiments to benchmark the transient and steady state performance of prototypical heat pipe space radiator elements are in preparation for testing in low earth orbit. It is anticipated that these heat pipes will be tested aborad the Space Shuttle in 1995. Three heat pipes will be tested in a cargo bay Get Away Special (GAS) canister. The heat pipes are SST/potassium, each with a different wick structure; homogeneous, arterial, and annular gap, the heat pipes have been designed, fabricated, and ground tested. In this paper, the heat pipe designs are specified, and transient and steady-state ground test data are presented.

    Woloshun, K.; Merrigan, M.A.; Sena, J.T. [Los Alamos National Lab., NM (United States); Critchley, E. [Phillips Lab., Kirtland AFB, NM (United States)

    1993-02-01

    111

    High temperature heat pipe experiments in low earth orbit  

    SciTech Connect

    Although high temperature, liquid metal heat pipe radiators have become a standard component on most high power space power system designs, there is no experimental data on the operation of these heat pipes in a zero gravity or micro-gravity environment. Experiments to benchmark the transient and steady state performance of prototypical heat pipe space radiator elements are in preparation for testing in low earth orbit. It is anticipated that these heat pipes will be tested aborad the Space Shuttle in 1995. Three heat pipes will be tested in a cargo bay Get Away Special (GAS) canister. The heat pipes are SST/potassium, each with a different wick structure; homogeneous, arterial, and annular gap, the heat pipes have been designed, fabricated, and ground tested. In this paper, the heat pipe designs are specified, and transient and steady-state ground test data are presented.

    Woloshun, K.; Merrigan, M.A.; Sena, J.T. (Los Alamos National Lab., NM (United States)); Critchley, E. (Phillips Lab., Kirtland AFB, NM (United States))

    1993-01-01

    112

    Surface Temperature Responses to Natural and Anthropogenic Influences: Past, Present, and Future  

    Microsoft Academic Search

    Earth's surface temperature is highly variable. Regional and seasonal changes, which can exceed the global mean variations by an order of magnitude, arise from both natural and anthropogenic influences, On time scales of years to a decade, naturally induced surface temperature changes related to the El Niño Southern Oscillation (ENSO), volcanic aerosols and solar activity can dominate current anthropogenic warming

    Judith Lean

    2010-01-01

    113

    Observations of TEC fluctuations from an explosion on the Earth`s surface  

    SciTech Connect

    The authors report observations of perturbations in the ionosphere total electron content (TEC) caused by acoustic waves propagating from a large chemical explosion in souther New Mexico at the earth`s surface. Fluctuations in TEC were measured by two arrays of receivers that monitor the phase of the 136 MHz beacons on two geostationary satellites. One array, located in northern New Mexico, observed fluctuations in the region where acoustic waves from the blast impinged directly on the ionosphere, while the second array, in Texas, was located to observe fluctuations caused by ducted acoustic waves. The TEC disturbance at the New Mexico array had an amplitude of about 2 {times} 10{sup 14} m{sup {minus}2} (more than 10 times the array noise level), while the amplitude at the Texas array, at a range of 900 km, was only a few times the instrumental noise level. Noise background analysis shows that the probability that a comparable or larger response at the New Mexico array might have been caused by a background noise event was less than 1%. The corresponding probability for the Texas array was 3%.

    Massey, R.S.; Carlos, R.C.; Jacobson, A.R.; Wu, G.

    1994-09-01

    114

    The Pseudo Radiation Energy Amplifier (PREA) and the mean earth s ground temperature  

    Microsoft Academic Search

    From the radiation balance diagram illustrating the IPCC reports one can estimate the power received by Earth from the sun at Pin = 342 W\\/m2 and the power consumed, remitted and reflected by the earth and its atmosphere at Pout = 599 kW\\/m2. It seems that the earth emits more power than it receives. The earth s ground mean temperature

    Ahmed Boucenna

    2008-01-01

    115

    Longitude: Linking Earth's ancient surface to its deep interior  

    NASA Astrophysics Data System (ADS)

    Earth scientists have had no direct way of calculating longitudes for times before those of the oldest hotspot track eruption sites in the Cretaceous (~ 130 Myr ago). For earlier times palaeomagnetic data constrain only ancient latitudes and continental rotations. We have recently devised a hybrid plate motion reference frame that permits the calculation of longitude back to Pangean assembly at ~ 320 Ma. This reference frame, here corrected for True Polar Wander (TPW), places most reconstructed Large Igneous Provinces (LIPs) of the past 300 Myr radially above the edges of the Large Low Shear wave Velocity Provinces (LLSVPs) in Earth's lowermost mantle. This remarkable correlation between surface and deep mantle features, which is also discernible for all hotspots with a deep-plume origin, provides a new way of reconstructing the original positions of LIP sites, and therefore the position of continents whose longitudes have hitherto been unknown. We place the 258 Ma Emeishan LIP eruption of South China at 4°N and 140°E, in that way constraining the width and the geometry of the Palaeotethys Ocean during the Late Permian. If LLSVPs have remained stable for even longer and TPW has been small, we can, under these assumptions, also restore Siberia and Gondwana longitudinally for Late Devonian (~ 360 Ma) and Late Cambrian (~ 510 Ma) times.

    Torsvik, Trond H.; Steinberger, Bernhard; Cocks, L. Robin M.; Burke, Kevin

    2008-12-01

    116

    Efficacy of surface applications with diatomaceous earth to control Rhyzopertha dominica (F.) (Coleoptera: Boxtrichidae) in stored wheat  

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Commercial formulations of diatomaceous earth (DE) products are labeled for use as surface treatments in stored wheat. However, they have not been evaluated as such against the lesser grain borer, Rhyzopertha dominica (F.), a major pest of stored wheat. An experiment was conducted at two temperature...

    117

    Pyrometric Gas and Surface Temperature Measurements.  

    National Technical Information Service (NTIS)

    A multiwavelength pyrometer possessing advantages over the one- and two-wavelength designs is described. Results of its application to surface temperature measurements of ceramics is presented. Also described is a probe suitable for gas temperature measur...

    G. Fralick D. Ng

    1999-01-01

    118

    A Revised Estimate of Earth's Surface Heat Flux: 47TW ± 2TW  

    NASA Astrophysics Data System (ADS)

    Earth's surface heat flux provides a fundamental constraint on solid Earth dynamics. However, deriving an estimate of the total surface heat flux is complex, due to the inhomogeneous distribution of heat flow measurements and difficulties in measuring heat flux in young oceanic crust, arising due to hydrothermal circulation. We derive a revised estimate of Earth's surface heat flux using a database of 38347 measurements (provided by G. Laske and G. Masters), representing a 55% increase on the number of measurements used previously, and the methods of Geographical Information Science (GIS) (Davies & Davies, 2010). To account for hydrothermal circulation in young oceanic crust, we use a model estimate of the heat flux, following the work of Jaupart et al., 2007; while for the rest of the globe, in an attempt to overcome the inhomogeneous distribution of measurements, we develop an average for different geological units. Two digital geology data sets are used to define the global geology: (i) continental geology - Hearn et al., 2003; and (ii) the global data-set of CCGM - Commission de la Carte Géologique du Monde, 2000. This leads to > 93,000 polygons defining Earth's geology. To limit the influence of clustering, we intersect the geology polygons with a 1 by 1 degree (at the equator) equal area grid. For each geology class the average heat flow in the resulting polygons is evaluated. The contribution of that geology class to the global surface heat flow is derived by multiplying the estimated surface heat flux with the area of that geology class. The total surface heat flow contributions of all the geology classes are summed. For Antarctica we use an estimate based on depth to Curie temperature and include a 1TW contribution from hot-spots in young ocean age. Geology classes with less than 50 readings are excluded. The raw data suggests that this method of correlating heat flux with geology has some power. Our revised estimate for Earth's global surface heat flux is 47 ± 2 TW, which is similar but slightly higher than previous estimates (e.g. Pollack et al., 1993 - 45 ± 1 TW; and Jaupart et al., 2007, - 46 ± 3 TW). It is challenging to reconcile such a high heat flow with estimates of internal heat sources in a monotonically cooling mantle. We will discuss alternative explanations and also how this work can be extended to produce a best estimate of the local heat flux globally.

    Davies, J.; Davies, R.

    2011-12-01

    119

    Method and apparatus for measuring temperature of an earth formation in the presence of a radio frequency electromagnetic field  

    SciTech Connect

    A method and apparatus for measuring the temperature in a subsurface earth formation that is being heated in situ by subjection to a radio frequency electromagnetic field. It includes lowering a maximum registering thermometer into the formation on a non-conductive flexible line, and holding it there long enough to reach the ambient temperature at that location. Then, the thermometer is raised to the surface fast enough to avoid any significant change on the way up to read that registered maximum.

    Kunetka, R.E.; Dowling, D.J.

    1984-09-04

    120

    Laboratory invesitgations: Low earth orbit environment chemistry with spacecraft surfaces  

    SciTech Connect

    Long-term space operations that require exposure of material to the low earth orbit (LEO) environment must take into account the effects of this highly oxidative atmosphere on material properties and the possible contamination of the spacecraft surroundings. Ground-based laboratory experiments at Los Alamos using a newly developed hyperthermal atomic oxygen (AO) source have shown that not only are hydrocarbon based materials effected but that inorganic materials such as MoS/sub 2/ are also oxidized and that thin (750A) protective coatings such as Al/sub 2/O/sub 3/ can be breached, producing oxidation of the underlying substrate material. Gas-phase reaction products, such as SO/sub 2/ from oxidation of MoS/sub 2/ and CO and CO/sub 2/ from hydrocarbon materials, have been detected and have consequences in terms of spacecraft contamination. Energy loss through gas-surface collisions causing spacecraft drag has been measured for a few select surfaces and has been found to be highly dependent on the surface reactivity. 10 refs., 11 figs.

    Cross, J.B.

    1989-01-01

    121

    Role of surface temperature in fluorocarbon plasma-surface interactions  

    SciTech Connect

    This article examines plasma-surface reaction channels and the effect of surface temperature on the magnitude of those channels. Neutral species CF{sub 4}, C{sub 2}F{sub 6}, and C{sub 3}F{sub 8} are produced on surfaces. The magnitude of the production channel increases with surface temperature for all species, but favors higher mass species as the temperature is elevated. Additionally, the production rate of CF{sub 2} increases by a factor of 5 as the surface temperature is raised from 25 Degree-Sign C to 200 Degree-Sign C. Fluorine density, on the other hand, does not change as a function of either surface temperature or position outside of the plasma glow. This indicates that fluorine addition in the gas-phase is not a dominant reaction. Heating reactors can result in higher densities of depositing radical species, resulting in increased deposition rates on cooled substrates. Finally, the sticking probability of the depositing free radical species does not change as a function of surface temperature. Instead, the surface temperature acts together with an etchant species (possibly fluorine) to elevate desorption rates on that surface at temperatures lower than those required for unassisted thermal desorption.

    Nelson, Caleb T.; Overzet, Lawrence J.; Goeckner, Matthew J. [Department of Electrical Engineering, University of Texas at Dallas, PO Box 830688, Richardson, TX 75083 (United States)

    2012-07-15

    122

    The Surface Area of Continents and Oceans and the Cooling of the Earth  

    Microsoft Academic Search

    The solid Earth looses it internal heat principally through convection. The oceanic lithosphere is the active upper thermal boundary layer of mantle convection and its overturn is critical to the Earth's mode of heat loss. Long lived, conducting continents at the Earth's surface locally insulate the convecting mantle and thus also effect global cooling rate. We explore the dynamics of

    A. Lenardic; L. Moresi; A. Jellinek; M. Manga; C. M. Cooper

    2005-01-01

    123

    Low Temperature Magnetic Properties of Some Rare Earth Trifluoromethanesulfonates.  

    NASA Astrophysics Data System (ADS)

    The rare earth trifluoromethanesulfonates, R(CF _7SO_3)_3.9H_2O (RTFMS), have a hexagonal structure similar to the familiar rare earth ethylsulfates, R(C_2H_5SO_4)_3.9H_2O (RES). The magnetic properties of RTFMS and RES analogs for many different rare earths were found to be quite similar. However, the correspondence in the behavior of these compounds appears to break down in the cases of Ce^ {3+}, Pr^{3+}, and Yb^{3+}. Electron paramagnetic resonance (EPR) spectra of single crystals of the rare earth ions rm Ce^{3+}, Pr^{3+}, and Yb^{3+} in the TFMS lattice were studied in the temperature range 1.2 K <= T <= 4.2 K and at frequencies of ~9 GHz and ~23 GHz. Resonances from the ground and first excited doublet of Ce^ {3+}, the accidentally degenerate ground doublet of Pr^{3+}, and the first and second excited doublets of Yb^ {3+} were observed. The single ion spectra of these compounds enabled us to establish the parallel and perpendicular components of the splitting factors of the various doublets that produced a signal, as well as the hyperfine constant for Pr^{3+} . EPR techniques were also used to study the nature of interionic interactions in CeTFMS and PrTFMS. An examination of the pair spectra of Ce^{3+} in LaTFMS revealed that virtual phonon exchange (VPE), while not as strong as in CeES, is the dominant non-dipolar interaction. The antiferromagnetic contribution to non-dipolar interactions in CeTFMS was found to be too weak to overcome the ferromagnetic contribution of dipolar interactions as it does in CeES. In PrTFMS a magnetic moment exists along the crystalline axis of symmetry with a larger electric dipole moment in the perpendicular plane. Short -range order of the one dimensional XY type and long-range order features were observed in the heat capacity. No indication of long-range ordering was observed in PrES. EPR of the pair spectra of Pr^{3+} in LaTFMS indicates that the interchain interactions are quite sizable allowing the establishment of long-range order. Virtual phonon exchange seems to be the dominant coupling mechanism. EPR and magnetic susceptibility measurements of YbTFMS indicate that there are deviations from the expected C_{3h} symmetry, exhibited by YbES, that shift the first and second excited doublets closer to the ground doublet. The symmetry lowering strains also appear to depend on the concentration of the Yb^{3+} ion. An analysis of the data assuming distortions that introduce terms of C_{3v} symmetry was adequate to explain our experimental results.

    Petasis, Doros T.

    1995-01-01

    124

    Surface-initiated group transfer polymerization mediated by rare earth metal catalysts.  

    PubMed

    We present the first example of a surface-initiated group transfer polymerization (SI-GTP) mediated by rare earth metal catalysts for polymer brush synthesis. The experimentally facile method allows rapid grafting of polymer brushes with a thickness of >150 nm in <5 min at room temperature. We show the preparation of common poly(methacrylate) brushes and demonstrate that SI-GTP is a versatile route for the preparation of novel polymer brushes. The method gives access to both thermoresponsive and proton-conducting brush layers. PMID:22497672

    Zhang, Ning; Salzinger, Stephan; Deubel, Frank; Jordan, Rainer; Rieger, Bernhard

    2012-04-17

    125

    Use of Radioactive Tracers for Selection of Rare Earth Precipitants and Ignition Temperatures.  

    National Technical Information Service (NTIS)

    Variations have been found in the specific activity of ignited radioactive-labeled rare earth oxide samples. The variations appear to depend on the precipitating agents and temperatures. Using various precipitating agents and different ignition temperatur...

    N. L. Smith E. S. Delucchi D. T. Mecozzi

    1979-01-01

    126

    Surface Temperatures of Avian Osteopetrotic Bones  

    PubMed Central

    Body temperatures and surface temperatures of metatarsal bones were recorded in normal and osteopetrotic chickens. Osteopetrotic lesions were 6.5 F warmer than normal bones but there was no corresponding increase in body temperature at a given environmental temperature. This indicates that the temperature elevation in the osteopetrotic lesion is a local phenomenon and not a systemic response. This also supports earlier observations that osteopetrotic bones feel warmer to the touch than normal bones. ImagesFig. 1.Fig. 2.

    Sanger, V. L.; Holt, J. A.; Reynolds, W. A.

    1965-01-01

    127

    Tropical Cyclones, Sea Surface Temperature, and Beyond  

    NSDL National Science Digital Library

    Part 1 The SAGUARO Exploring GIS Investigations for Earth Science curriculum requries the use of ESRI's ArcViewà GIS software version 3.0 for Macintosh or 3.2 and higher for PC. Use ArcGIS and data files from the SAGUARO Project's (http://www.scieds.com/saguaro/etc.html) Exploring Tropical Cyclones investigations. After the students are introduced to the program they are asked to determine what criteria are required for the formation of tropical cyclones. Exploring Tropical Cyclones Unit 1 has a great deal of data for the students to use. The data is presented as layers on a world map. Different features can be turned on and off at will, and layers can be brought in from other units if desired. Features they can work with are: August SST February SST tropical cyclone tracks locations of tropical cyclone formation for Jun-Sep locations of tropical cyclone formation for Dec-Mar Part 2 Students are divided into small groups (3-4 students works well) where they compare their findings (including what evidence they used) with the findings of the other group members. Each group is then asked to determine the threshold temperature for tropical cyclone formation as well as to calculate the area of the ocean that has SST equal to or above this threshold temperature (you can have them calculate this for each season, or as a total area including both February and August data). Part 3 Class discussion of what they have found so far. Introduce them to model predictions of SST for different atmospheric CO2 levels. Propose a 2 degree C increase in tropical SST and ask what they think that will mean. What other factors might influence the formation of tropical cyclones? Part 4 Assign an article or two (ideally a published peer reviewed article - to introduce them to this type of scientific writing - that is if you can find one that you consider appropriate for your students) that introduces them to other factors required for tropical cyclone formation and predictions of how climate change might affect them. For example an article that discusses the role of wind speed near the surface of the ocean, or vertical wind shear, or one that shows that the threshold temperature is actually predicted to increase by the same magnitude as the SST increase. Have them write a report that summaries the criteria for cyclogenesis as well as explaining how they would go about predicting where tropical cyclones will form as a result of an increased SST. They do not need to perform all of the tests they propose! They should state what sort of information they would like to obtain and why.

    Schmitt, Danielle

    128

    Impact hot spots on the cold surface of the early Earth  

    NASA Astrophysics Data System (ADS)

    The cooling rates for a thin upper layer of impact-melted material on the surface of the growing Earth were calculated using the experimental data for convective heat transfer coefficient. The presence of an atmosphere on the Earth embryo leads to very high cooling rates of the surface layer of impact crater. We find that during Safronov's type of accretion more than 90% of the Earth's surface was below the freezing point of water and the blanketing effect of greenhouse gases was unable to maintain a global magma ocean on Earth.

    Mukhin, L. M.; Pimenov, K. Yu.

    2002-01-01

    129

    Crustal growth, thermal evolution of the Earth, and Archaean emerged land surface  

    NASA Astrophysics Data System (ADS)

    In the long term, the total amount of emerged land at Earth's surface and the depth of mid-oceanic ridges are controlled by the growth of the continental crust and by the secular cooling of Earth's mantle that implies changes in the isostatic balance between continents and oceans. The evolution of the area of emerged land and of oceanic bathymetry are of fundamental importance to the geochemical coupling of mantle, continental crust, ocean and atmosphere. We developed a model to evaluate the area of emerged continental crust as a function of mantle temperature, continental area and hypsometry. For constant continental hypsometry and for three different thermal evolution models, we find that a constant continental freeboard (± 200 m) throughout Earth's history is possible as long as the potential temperature of the upper mantle never exceeded its present value by more than 110-210°C. This implies either a very limited cooling of the planet or, most likely, a change in continental freeboard since the Archaean. As for the area of emerged land, our calculations suggest that less than ~12% of Earth's surface were emerged in the Archaean, compared to ~28% at present. Of importance to the evolution of the area of emerged land is the shape of the continents. During the Archaean, a greater radiogenic crustal heat production and a possibly greater mantle heat flow would have reduced the strength of the continental lithosphere, thus limiting crustal thickening due to mountain building processes and the maximum elevation in Earth's topography (Rey and Coltice, 2008). Taking this effect into account, we show that the continents were mostly flooded until the end of the Archaean, with 2-3% of Earth's area emerged by 2.5 Ga. These results are consistent with the widespread occurrence of submarine continental flood basalts in the Archaean, and with the appearance and strengthening of the geochemical fingerprint of felsic sources in the sedimentary record from 2.5 Ga. In order to investigate the influence of crustal growth models on the area of emerged land and on the evolution of oceanic 87Sr/86Sr, we developed an integrated model based on the thermal evolution model of Labrosse and Jaupart (2007). Modelling results suggest that the area of emerged land does not closely depend on crustal growth models, and that less than 5% of Earth's area was emerged in the Archaean. Furthermore, our models reconcile early crustal growth models with the evolution of oceanic 87Sr/86Sr as recorded by marine carbonates when a reduced emerged area and lower continental elevations are accounted for. Thus, a delayed crustal growth model is not needed to account for the observed trend in oceanic 87Sr/86Sr. References Labrosse, S., Jaupart, C., 2007. Thermal evolution of the Earth: Secular changes and fluctuations of plate characteristics. Earth Planet. Sc. Lett. 260, 465-481. Rey, P. F., Coltice, N., 2008. Neoarchean strengthening of the lithosphere and the coupling of the Earth's geochemical reservoirs. Geology 36, 635-638.

    Flament, Nicolas; Coltice, Nicolas; Rey, Patrice

    2010-05-01

    130

    Surface Temperatures As Titan Enters Northern Spring  

    NASA Astrophysics Data System (ADS)

    The Composite Infrared Spectrometer (CIRS) aboard Cassini has been measuring surface brightness temperatures on Titan since early in the mission, covering a period spanning late northern winter into early northern spring. The far-infrared portion of CIRS detects radiation emitted from the surface that reaches space through a spectral window of low atmospheric opacity at 19 microns wavelength. We previously reported surface temperatures from the portion of the mission prior to May 2008 that showed the north to be about 1 K colder than the south, appropriate to northern winter [1]. As Titan passed through northern spring equinox CIRS has been able to demonstrate that a shift took place to a more symmetric north-south distribution in temperatures [2]. Around equinox the temperature at the equator was 93.4 K and the poles were both near 91 K. The equatorial temperature was close to the value found at the surface by Huygens [3]. At equinox there remained a slight offset in peak temperatures toward the south, and the change in this offset from late northern winter suggests a seasonal lag of ?Ls = 9º solar longitude. This would place the time of northsouth symmetry at the same seasonal phase as the Voyager 1 encounter, just following the previous northern spring equinox. Voyager IRIS saw a northsouth temperature symmetry [4,5], and we conclude that the surface temperature distribution is repeating after one Titan year. Through a comparison with predictions from general circulation models, the measured temperatures and their seasonal changes provide constraints on the characteristics of the surface material. Of the two scenarios of Tokano [6], porous ice regolith and rock-ice mixture, the former is a closer match to the measurements. This implies that the surface has a relatively low thermal inertia. As Titan progresses toward northern summer the seasonal shift in surface heating is expected to alter Titan's weather and global circulation. CIRS will continue to monitor changes in the surface temperatures through Cassini's extended mission.

    Jennings, D. E.; Cottini, V.; Nixon, C. A.

    2011-10-01

    131

    Distribution of UV radiation at the Earth's surface from TOMS-measured UV-backscattered radiances  

    Microsoft Academic Search

    Daily global maps of monthly integrated UV-erythemal irradiance (290-400 nm) at the Earth's surface are estimated using the ozone amount, cloud transmittance, aerosol amounts, and surface reflectivity from the solar UV radiation backscattered from the Earth's atmosphere as measured by the total ozone mapping spectrometer (TOMS) and independently measured values of the extraterrestrial solar irradiance. The daily irradiance values at

    J. R. Herman; N. Krotkov; E. Celarier; D. Larko; G. Labow

    1999-01-01

    132

    TOWARDS A UNIFIED SCIENCE OF THE EARTH'S SURFACE: OPPORTUNITIES FOR SYNTHESIS BETWEEN HYDROLOGY, GEOMORPHOLOGY AND ECOLOGY  

    Microsoft Academic Search

    The Earth's surface is shaped by the interaction of tectonics, water, sediment, solutes, and biota over a wide range of spatial and temporal scales and across diverse environments. Development of a predictive science of Earth-surface dynamics would integrate many disciplines and approaches, including hydrology, geomorphology, atmospheric science, biology, sedimentary and structural geology, and ecology. This paper discusses challenges, opportunities, and

    Chris Paola; Efi Foufoula-Georgiou; William E. Dietrich; Miki Hondzo; David Mohrig; Gary Parker; Mary E. Power; Ignacio Rodriguez-Iturbe; Vaughan Voller; Peter Wilcock

    2005-01-01

    133

    The Propagation of Radio Waves over the Surface of the Earth and in the Upper Atmosphere  

    Microsoft Academic Search

    Simple formulas and graphs are given which represent the ground-wave field intensity at the surface of the earth as radiated from a short vertical antenna at the surface of the earth. The theory is compared to some experimental results reported by other investigators to determine its range of application. The diffraction formula given is theoretically valid only at the lower

    K. A. Norton

    1936-01-01

    134

    Low Temperature Magnetic Properties of Some Rare Earth Trifluoromethanesulfonates  

    Microsoft Academic Search

    The rare earth trifluoromethanesulfonates, R(CF _7SO_3)_3.9H_2O (RTFMS), have a hexagonal structure similar to the familiar rare earth ethylsulfates, R(C_2H_5SO_4)_3.9H_2O (RES). The magnetic properties of RTFMS and RES analogs for many different rare earths were found to be quite similar. However, the correspondence in the behavior of these compounds appears to break down in the cases of Ce^ {3+}, Pr^{3+}, and

    Doros T. Petasis

    1995-01-01

    135

    A unified approach to orbital, solar, and lunar forcing based on the Earth’s latitudinal insolation/temperature gradient  

    NASA Astrophysics Data System (ADS)

    Widespread empirical evidence suggests that extraterrestrial forcing influences the Earth’s climate, but how this could occur remains unclear. Here we describe a new approach to this problem that unifies orbital, solar and lunar forcing based on their common control of the Earth’s latitudinal insolation gradient (LIG). The LIG influences the climate system through differential solar heating between the tropics and the poles that gives rise to the latitudinal temperature gradient (LTG), which drives the Earth’s atmospheric and (wind driven) ocean circulation. We use spectral analysis of recent changes in the Earth’s LTG to support earlier work on orbital timescales (Davis and Brewer, 2009) that suggests the climate system may be unusually sensitive to changes in the LIG. Identification of LIG forcing of the LTG is possible because the LIG varies according to seasonally specific periodicities based on obliquity in summer (41 kyr orbital and 18.6 yr lunar cycle), and precession (21 kyr orbital cycle) and total solar irradiance (11 yr solar cycle) in winter. We analyse changes in the Northern Hemisphere LTG over the last 120 years and find significant (99%) peaks in spectral frequencies corresponding to 11 years in winter and 18.6 years in summer, consistent with LIG forcing. The cross-seasonal and multi-frequency nature of the LIG signal, and the diffuse effect of the LTG driver on the climate system may account for the complexity of the response to extraterrestrial forcing as seen throughout the climatic record. This hypersensitivity of the LTG to the LIG appears poorly reproduced in climate models, but would be consistent with the controversial theory that the LTG is finely balanced to maximise entropy.

    Davis, Basil A. S.; Brewer, Simon

    2011-07-01

    136

    Thermal expansion and Debye temperature of rare earth-doped ceria  

    Microsoft Academic Search

    Thermal expansions of un-doped ceria and rare earth-doped ceria (Ce1?xMxO2?x\\/2, M=La, Sm, Dy, Yb) were measured in the temperature range from 100 to 800K by TMA. Debye temperatures of these compounds were measured at room temperature by an ultrasonic pulse method. The thermal expansion coefficients of rare earth-doped CeO2 increased with increasing ionic radius of doped ions and its M

    Tetsuo Hisashige; Yasuhisa Yamamura; Toshihide Tsuji

    2006-01-01

    137

    Earth surface reflectance climatology from 3 years of OMI data  

    NASA Astrophysics Data System (ADS)

    Global maps of the Earth's surface Lambertian equivalent reflectance (LER) are constructed using 3 years of Ozone Monitoring Instrument (OMI) measurements obtained between October 2004 and October 2007 at 23 wavelengths between 328 and 500 nm. The maps are constructed on a 0.5° by 0.5° longitude-latitude grid for each calendar month using an algorithm based on temporal histograms of the observed LER values per geophysical location. The algorithm allows seasonal effects related to vegetation, snow, and ice but excludes statistical outliers. The maps show typical features like open ocean regions with high reflectivity indicative of low phytoplankton levels, coastal waters with high reflectance caused by silt, and oceanic regions with low reflectance correlated with chlorophyll. Open oceans in general have a higher reflectivity than does land up to 420 nm. The highest reflectivity values of oceans occur at 380 nm. Good agreement is found with a similar LER map based on data from the Total Ozone Mapping Spectrometer (TOMS) at 331, 340, 360, and 380 nm, which is 0.015 lower on average. The comparison with data from the Global Ozone Monitoring Experiment (GOME) at 335, 380, 440, and 494 nm is also satisfactory, being 0.005 lower on average. The LER derived from OMI data is approximately 0.02 higher than the black sky albedo as derived from the Moderate Resolution Imaging Spectroradiometer at 470 nm, which is partly related to viewing geometry effects of the bidirectional reflectance distribution function of the surface. The data set presented contains residual cloud features over tropical rain forest regions, has a higher spatial resolution than those created using TOMS and GOME data, and includes more wavelengths.

    Kleipool, Q. L.; Dobber, M. R.; de Haan, J. F.; Levelt, P. F.

    2008-09-01

    138

    Global Monthly Sea Surface Temperature Climatology.  

    National Technical Information Service (NTIS)

    A new global 2 degrees x 2 degrees monthly sea surface temperature (SST) climatology, primarily derived from a 1950 to 1979 based SST climatology from the Climate Analysis Center (CAC), is presented and described. The purpose of developing this climatolog...

    D. J. Shea K. E. Trenberth R. W. Reynolds

    1990-01-01

    139

    Sea Surface Temperatures from VAS MSI Data.  

    National Technical Information Service (NTIS)

    A procedure is developed for estimating sea surface temperatures from multispectral image data acquired from the VISSR atmospheric sounder on the geostationary GOES satellites. Theoretical regression equations for two and three infrared window channels ar...

    J. J. Bates

    1984-01-01

    140

    Ocean Remote Sensing: Sea Surface Temperature Imagery  

    NSDL National Science Digital Library

    This site presents rapidly processed estimates of sea surface temperature for various regions along the east coast of the United States, including the Gulf Stream, Chesapeake Bay, the Gulf of Mexico and the Bahamas. The imagery includes both single pass data and composite data from multiple passes. Included at this site is a primer on the measurement of sea surface temperature. Additional links satellite links are provided. See related links for the topics.

    141

    Precision radiometric surface temperature (PRST) sensor  

    NASA Astrophysics Data System (ADS)

    There is a need for a Precision Radiometric Surface Temperature (PRST) measurement capability that can achieve noncontact profiling of a sample's surface temperature when heated dynamically during laser processing, aerothermal heating or metal cutting/machining. Target surface temperature maps within and near the heated spot provide critical quantitative diagnostic data for laser-target coupling effectiveness and laser damage assessment. In the case of metal cutting, this type of measurement provides information on plastic deformation in the primary shear zone where the cutting tool is in contact with the workpiece. The challenge in these cases is to measure the temperature of a target while its surface's temperature and emissivity are changing rapidly and with incomplete knowledge of how the emissivity and surface texture (scattering) changes with temperature. Bodkin Design and Engineering, LLC (BDandE), with partners Spectral Sciences, Inc. (SSI) and Space Computer Corporation (SCC), has developed a PRST Sensor that is based on a hyperspectral MWIR imager spanning the wavelength range 2-5 ?m and providing a hyperspectral datacube of 20-24 wavelengths at 60 Hz frame rate or faster. This imager is integrated with software and algorithms to extract surface temperature from radiometric measurements over the range from ambient to 2000K with a precision of 20K, even without a priori knowledge of the target's emissivity and even as the target emissivity may be changing with time and temperature. In this paper, we will present a description of the PRST system as well as laser heating test results which show the PRST system mapping target surface temperatures in the range 600-2600K on a variety of materials.

    Daly, James T.; Roberts, Carson; Bodkin, Andrew; Sundberg, Robert; Beaven, Scott; Weinheimer, Jeffrey

    2013-05-01

    142

    Southwest Subtropical Pacific Surface Temperatures during the Pliocene  

    NASA Astrophysics Data System (ADS)

    The early Pliocene (~4.6 - 4.8 Ma) is an important geological interval for understanding future climate change, since CO2 levels during the Pliocene are very similar to those of today. Scientists do not know much about Earth's climate during this time period, so additional sea surface temperature measurements from the Western and Eastern Pacific, particularly from the southern hemisphere, are needed to validate and improve the ability of climate models to simulate warm climatic states. I measured sea surface temperature records from the Southwest Pacific DSDP Site 207A in the Tasman Sea (36° 58'S, 165° 26'E, 1389 meters water depth) using Mg/Ca records from Orbulina universa. Sea surface temperatures at Site 207A were ~4°C warmer during the early Pliocene compared to present day. These analyses provide strong evidence, when compared to other published data from the west Pacific, for an expanded west Pacific warm pool; this has implications for how processes such as heat transport are altered during warm periods. By examining tropical and subtropical sites from the Pliocene, we are able to obtain more sea surface temperature data which will help improve current climate models and lead to a greater understanding of the Pliocene and future climate change.

    Chopra, S.; Ford, H. L.; Ravelo, A. C.

    2011-12-01

    143

    The role of air temperature in the seasonal variation of the earth's rotation  

    Microsoft Academic Search

    Using observed data over many years, the present study calculates, for each month and each air layer, the temperature differences between the poles and the equator and between the two hemispheres, and the seasonal variations in the spin velocity of the earth, and analyzes their relations with the angular momentum of the atmosphere of the whole earth and the change

    G.-B. Peng

    1984-01-01

    144

    Effect of fossil fuels and introduction of hydrogen on Earth's temperature  

    Microsoft Academic Search

    A computer model has been developed to calculate the effect of atmospheric COâ concentration and introduction of hydrogen on the Earth's mean temperature. The results were checked with the historical data. After the validity of the model had been established, the computer program was run for the years 1985 through 2100 to estimate the atmospheric COâ concentrations and the Earth's

    Gurkan

    1985-01-01

    145

    Calculation of surface tension temperature coefficients  

    SciTech Connect

    In three previous communications the relationship between bulk properties and the surface tension of liquid metals and alloys was demonstrated. The surface tension of liquid metals was correlated with plasma frequency. It was then shown that the surface tension of liquid metals as well as alloys could be obtained from the bulk modulus and most recently a method was given for predicting the surface tension from the plasma frequency of the constituents of a binary alloy. The purpose of the present communication is to show that the temperature coefficient of surface tension of liquid metals may be calculated from another bulk property - the bulk coefficient of thermal expansion.

    Papazian, H.A.

    1984-12-01

    146

    Transformer winding temperature estimation based on tank surface temperature  

    NASA Astrophysics Data System (ADS)

    Power transformers are among the most valuable assets of the electrical grid. Since the largest units cost in the order of millions of dollars, it is desirable to operate them in such a manner that extends their remaining lives. Operating these units at high temperature will cause excessive insulation ageing in the windings. Consequently, it is necessary to study the thermal performance of these expensive items. Measuring or estimating the winding temperature of power transformers is beneficial to a utility because this provides them with the data necessary to make informed decisions on how best to use their assets. Fiber optic sensors have recently become viable for the direct measurement of winding temperatures while a transformer is energized. However, it is only practical to install a fiber optic temperature sensor during the manufacture of a transformer. For transformers operating without fiber optic sensors, the winding temperature can be estimated with calculations using the temperature of the oil at the top of the transformer tank. When the oil temperature measurement is not easily available, the temperature of the tank surface may be used as an alternative. This paper shows how surface temperature may be utilized to estimate the winding temperature within a transformer designed for research purposes.

    Guo, Wenyu; Wijaya, Jaury; Martin, Daniel; Lelekakis, Nick

    2011-03-01

    147

    Radiometric and equivalent isothermal surface temperatures  

    Microsoft Academic Search

    The analytical solution for the heat flux from an anisothermal canopy developed from K theory by Brutsaert and Sugita [1996] (hereinafter referred to as B&S) has been extended to provide a parameterization of the difference between the radiometric and the equivalent isothermal surface temperature. The latter is the isothermal temperature at which a canopy would give the correct sensible heat

    Richard D. Crago

    1998-01-01

    148

    MONITORING SURFACE TEMPERATURE OF IRRADIATED FUEL ELEMENTS  

    Microsoft Academic Search

    A radiation thermometer using infrared techniques was developed to ; monitor surface temperatures of irradiated fuel elements while undergoing ; physical examination. Thermistors were chosen as sensors for the infrared ; thermometer as they are the most responsive transducer in the temperature range ; of interest here, namely from 600 to 100 deg F, and possess the required ; tolerance

    1963-01-01

    149

    Enceladus Near-Fissure Surface Temperatures  

    NASA Astrophysics Data System (ADS)

    Recently reported Cassini VIMS observations of thermal emission from the Enceladus south-pole fissures (Goguen et al. 2013) when combined with previous longer wavelength Cassini CIRS observations (Spencer et al. 2006) allow us to better constrain the highest temperatures present, but also require more detailed modeling of the processes which control those highest temperatures. The simplest interpretation of the VIMS observations is that the 3-5 µm thermal radiation comes from the walls within a fissure, rather than the adjacent surface. But as part of investigating that latter alternative it became clear that very high sublimation rates are implied by some predicted surface temperatures. Abramov and Spencer (2009) produced models of the expected surface temperature distribution, assuming conduction of heat through the ice, balanced by thermal radiation at the surface. However as temperature is raised, at 186K sublimation cooling equals radiation, and because it depends exponentially on temperature, it quickly dominates. We have found that including the surface sublimation cooling suppresses the higher temperatures. Regardless of the fissure temperature, surface temperatures above 200K can only be maintained by conduction within a few tens of centimeters of the assumed fissure wall. The high sublimation erosion rates (0.25 m/yr at 180K, rising to over 100 m/yr at 220K) imply that the fixed boundaries we have previously assumed are unrealistic. If these surface temperatures are maintained then either a sublimation lag of non-ice components will accumulate, inhibiting sublimation, or the geometry of the fissure vent will rapidly change. However the rate of change will be limited by the available heat provided by conduction. We are now developing numerical models with moving boundary conditions to explore the time evolution. The simplest result may be that the lip of the fissure erodes back till it no longer remains in thermal contact with the rising vapor which maintains the high fissure temperatures. Ingersoll and Pankine (2010) have explored the importance of vapor/ice equilibrium within the fissure. Those same physical principles will also control the surface temperature near the fissures.

    Howell, Robert R.; Goguen, J. D.; Spencer, J. R.

    2013-10-01

    150

    Transport of radon and thoron at the earth`s surface. Progress report, 1 January 1991--1 January 1992  

    SciTech Connect

    This report covers progress under the current funding period Jan. 1, 1991 to Jan. 1, 1992 and presents the continuation proposal for Jan. 1, 1992 to Jan. 1, 1993. The previous progress report was submitted in May 1990, so activities during the last half of 1990 will also be included. Major activities over the last year have centered on the study of disequilibrium of radon progeny near the earth`s surface and the sources of thoron in indoor air. In addition, we have carried out supplemental measurements of radon sorption coefficients in porous materials focusing on the physical mechanism of sorption.

    Schery, S.D.

    1991-06-15

    151

    Temperature dependence of magnetic EXAFS for rare earth elements  

    Microsoft Academic Search

    A systematic study of the x-ray magnetic circular dichroism at the L3 edge is presented for Gd and Tb single crystals in the extended energy range (MEXAFS). The investigation of the dichroic signal in this energy range is especially interesting for rare earth metals because the relative intensity of the magnetic EXAFS to the near edge signal (XMCD) is much

    H. Wende; A. Scherz; C. Sorg; Z. Li; P. Poulopoulos; K. Baberschke; A. L. Ankudinov; J. J. Rehr; F. Wilhelm; N. Jaouen; A. Rogalev; D. L. Schlagel; T. A. Lograsso

    2005-01-01

    152

    Temperature Dependence of Resistivity of Sintered Rare-Earth Permanent-Magnet Materials  

    Microsoft Academic Search

    We studied the resistivity of rare-earth permanent-magnet materials over the temperature range -40°C to +150°C. We investigated three different materials from four manufacturers, including Nd2 Fe14 B, SmCo5 , and Sm2 Co17 , and measured their resistivities and temperature coefficients. We found that rare-earth permanent-magnet materials show an anisotropic resistivity behavior. In fact, the resistivity anisotropy causes larger resistivity difference

    Sami Ruoho; Minna Haavisto; Eelis Takala; Timo Santa-Nokki; Martti Paju

    2010-01-01

    153

    Titan Surface Temperatures from Cassini CIRS  

    NASA Astrophysics Data System (ADS)

    Thermal radiation from the surface of Titan reaches space through a spectral window at 19-microns wavelength. After removing the effects of the atmosphere, measurement of this radiance gives the brightness temperature of the surface. The Composite Infrared Spectrometer1 (CIRS) has made such measurements during the Cassini prime mission. These observations cover a wide range of emission angles, thereby constraining the contributions from atmospheric radiance and opacity. With the more complete latitude coverage and much larger dataset, we have been able to improve upon the original results from Voyager IRIS.2,3 CIRS measures an equatorial surface brightness temperature, averaged over longitude, of 93.7±0.6 K. This agrees with the HASI4 temperature at the Huygens landing site. The latitude dependence of surface brightness temperature exhibits an approximately 2 K decrease toward the South Pole and 3 K decrease toward the North Pole. The lower surface temperatures seen at high latitudes are consistent with conditions expected for lake formation. 1Flasar, F. M. et al., Space Science Reviews 115, 169 (2004). 2Flasar, F. M., Samuelson, R. E., & Conrath, B. J., Nature 292, 693 (1981). 3Courtin, R., & Kim, S. J., Planetary and Space Science 50, 309 (2002). 4Fulchignoni, M. et al., Nature 438, 785 (2005).

    Jennings, Donald E.; Flasar, F. M.; Kunde, V. G.; Samuelson, R. E.; Pearl, J. C.; Nixon, C. A.; Carlson, R. C.; Mamoutkine, A. A.; Brasunas, J. C.; Guandique, E.; Achterberg, R. K.; Bjoraker, G. L.; Romani, P. N.; Segura, M. E.; Albright, S. A.; Elliott, M. H.; Tingley, J. S.; Calcutt, S.; Coustenis, A.; Bézard, B.; Courtin, R.

    2008-09-01

    154

    Comparison between Sea Surface Temperature in the Equatorial Eastern Pacific and United States Surface Temperatures  

    Microsoft Academic Search

    The average sea surface temperature in the equatorial eastern Pacific (0-10°S, 180-90°W, and hereafter known as SST() has been compared with United States surface temperatures for winter and summer (and to a lesser extent spring and autumn) and the year as a whole. Based on year-average temperatures during the period 1931-77, Pacific Coast temperatures have been in phase with SST(,

    J. K. Angell; J. Korshover

    1981-01-01

    155

    Efficacy of surface applications with diatomaceous earth to control Rhyzopertha dominica (F.) (Coleoptera: Bostrichidae) in stored wheat  

    Microsoft Academic Search

    Commercial formulations of diatomaceous earth (DE) products labeled for use as grain protectants usually specify on the label the depth for using them as a surface treatment, which is often 30.5cm. An experiment was conducted at two temperatures (27 and 32°C) and three exposure intervals (7, 10 and 14d), at a relative humidity of 57–60% to determine if Rhyzopertha dominica

    Erika A. Vardeman; Frank H. Arthur; James R. Nechols; James F. Campbell

    2007-01-01

    156

    Seasonal Changes in Titan's Surface Temperatures  

    NASA Astrophysics Data System (ADS)

    Seasonal changes in Titan's surface brightness temperatures have been observed by Cassini in the thermal infrared. The Composite Infrared Spectrometer measured surface radiances at 19 ?m in two time periods: one in late northern winter (LNW; Ls = 335°) and another centered on northern spring equinox (NSE; Ls = 0°). In both periods we constructed pole-to-pole maps of zonally averaged brightness temperatures corrected for effects of the atmosphere. Between LNW and NSE a shift occurred in the temperature distribution, characterized by a warming of ~0.5 K in the north and a cooling by about the same amount in the south. At equinox the polar surface temperatures were both near 91 K and the equator was at 93.4 K. We measured a seasonal lag of ?LS ~ 9° in the meridional surface temperature distribution, consistent with the post-equinox results of Voyager 1 as well as with predictions from general circulation modeling. A slightly elevated temperature is observed at 65° S in the relatively cloud-free zone between the mid-latitude and southern cloud regions.

    Jennings, D. E.; Cottini, V.; Nixon, C. A.; Flasar, F. M.; Kunde, V. G.; Samuelson, R. E.; Romani, P. N.; Hesman, B. E.; Carlson, R. C.; Gorius, N. J. P.; Coustenis, A.; Tokano, T.

    2011-08-01

    157

    Geometric effects modelling for the PJM interconnection system. Part 1; Earth surface potentials computation  

    SciTech Connect

    This paper describes an ionospheric source current model and development of an earth resistivity model used to calculate geomagnetic induced currents (GIC) on the Pennsylvania-New Jersey-Maryland Interconnection (PJM). Ionospheric current is modelled as a gaussian distributed current sheet above the earth. Geological details are included by dividing the PJM service area into 11 different earth resistivity regions. The resulting earth surface potential (ESP) at each power system substation is then calculated. A companion paper describes how this ESP is applied to the power system model to calculate the geomagnetic induced current in the power system equipment and facilities.

    Towle, J.N. (Diversified EM, Seattle, WA (US)); Prabhakara, F.S. (Power Technologies, Inc., Schenectady, NY (US)); Ponder, J.Z. (PJM Interconnection, Norristown, PA (US))

    1992-07-01

    158

    Earth Surface Monitoring with COSI-Corr, Techniques and Applications  

    NASA Astrophysics Data System (ADS)

    Co-registration of Optically Sensed Images and Correlation (COSI-Corr) is a software package developed at the California Institute of Technology (USA) for accurate geometrical processing of optical satellite and aerial imagery. Initially developed for the measurement of co-seismic ground deformation using optical imagery, COSI-Corr is now used for a wide range of applications in Earth Sciences, which take advantage of the software capability to co-register, with very high accuracy, images taken from different sensors and acquired at different times. As long as a sensor is supported in COSI-Corr, all images between the supported sensors can be accurately orthorectified and co-registered. For example, it is possible to co-register a series of SPOT images, a series of aerial photographs, as well as to register a series of aerial photographs with a series of SPOT images, etc... Currently supported sensors include the SPOT 1-5, Quickbird, Worldview 1 and Formosat 2 satellites, the ASTER instrument, and frame camera acquisitions from e.g., aerial survey or declassified satellite imagery. Potential applications include accurate change detection between multi-temporal and multi-spectral images, and the calibration of pushbroom cameras. In particular, COSI-Corr provides a powerful correlation tool, which allows for accurate estimation of surface displacement. The accuracy depends on many factors (e.g., cloud, snow, and vegetation cover, shadows, temporal changes in general, steadiness of the imaging platform, defects of the imaging system, etc...) but in practice, the standard deviation of the measurements obtained from the correlation of mutli-temporal images is typically around 1/20 to 1/10 of the pixel size. The software package also includes post-processing tools such as denoising, destriping, and stacking tools to facilitate data interpretation. Examples drawn from current research in, e.g., seismotectonics, glaciology, and geomorphology will be presented. COSI-Corr is developed in IDL (Interactive Data Language), integrated under the user friendly interface ENVI (Environment for Visualizing Images), and is distributed free of charge for academic research purposes.

    Leprince, S.; Ayoub, F.; Avouac, J.

    2009-12-01

    159

    Modelling the rheology of MgO under Earth's mantle pressure, temperature and strain rates.  

    PubMed

    Plate tectonics, which shapes the surface of Earth, is the result of solid-state convection in Earth's mantle over billions of years. Simply driven by buoyancy forces, mantle convection is complicated by the nature of the convecting materials, which are not fluids but polycrystalline rocks. Crystalline materials can flow as the result of the motion of defects--point defects, dislocations, grain boundaries and so on. Reproducing in the laboratory the extreme deformation conditions of the mantle is extremely challenging. In particular, experimental strain rates are at least six orders of magnitude larger than in nature. Here we show that the rheology of MgO at the pressure, temperature and strain rates of the mantle is accessible by multiscale numerical modelling starting from first principles and with no adjustable parameters. Our results demonstrate that extremely low strain rates counteract the influence of pressure. In the mantle, MgO deforms in the athermal regime and this leads to a very weak phase. It is only in the lowermost lower mantle that the pressure effect could dominate and that, under the influence of lattice friction, a viscosity of the order of 10(21)-10(22) pascal seconds can be defined for MgO. PMID:22237109

    Cordier, Patrick; Amodeo, Jonathan; Carrez, Philippe

    2012-01-11

    160

    Barometric pressure, dry bulb temperature and vapor pressure at the lowest terrestrial site on earth, Dead Sea basin, Neve Zohar, Israel  

    Microsoft Academic Search

    Summary  The Dead Sea basin is located at the lowest terrestrial site on the earth and, thereby, has the tallest atmospheric air column\\u000a above its surface. Consequently, the Dead Sea basin is expected, a priori, to have the highest terrestrial barometric pressure\\u000a and, thereby, the highest molecular oxygen density on the earth. The barometric pressure and dry bulb temperature have been

    A. I. Kudish; E. G. Evseev

    2006-01-01

    161

    Differences between near-surface equivalent temperature and temperature trends for the Eastern United States. Equivalent temperature as an alternative measure of heat content  

    USGS Publications Warehouse

    There is currently much attention being given to the observed increase in near-surface air temperatures during the last century. The proper investigation of heating trends, however, requires that we include surface heat content to monitor this aspect of the climate system. Changes in heat content of the Earth's climate are not fully described by temperature alone. Moist enthalpy or, alternatively, equivalent temperature, is more sensitive to surface vegetation properties than is air temperature and therefore more accurately depicts surface heating trends. The microclimates evident at many surface observation sites highlight the influence of land surface characteristics on local surface heating trends. Temperature and equivalent temperature trend differences from 1982-1997 are examined for surface sites in the Eastern U.S. Overall trend differences at the surface indicate equivalent temperature trends are relatively warmer than temperature trends in the Eastern U.S. Seasonally, equivalent temperature trends are relatively warmer than temperature trends in winter and are relatively cooler in the fall. These patterns, however, vary widely from site to site, so local microclimate is very important. ?? 2006 Elsevier B.V. All rights reserved.

    Davey, C. A.; Pielke, Sr. , R. A.; Gallo, K. P.

    2006-01-01

    162

    Chemical Sputtering of Deuterated Carbon Surfaces at Various Surface Temperatures  

    SciTech Connect

    The chemical sputtering of deuterated amorphous carbon (a-C:D) surfaces irradiated by 1 50 eV deuterium atoms at surface temperatures between 300 1000 K was studied using classical molecular dynamics. A quasi-stationary state was reached by cumulative bombardment for each energy and temperature. Results were compared with available experimental data and previous modeling results, and the applicability of molecular dynamics for thermally generated processes was discussed. An attempt is made to correct the absence of the thermally stimulated desorption/degassing form the MD simulations, which evolve at the longer time scales.

    Dadras, J. [University of Tennessee, Knoxville (UTK); Krstic, Predrag S [ORNL

    2010-01-01

    163

    30 CFR 18.23 - Limitation of external surface temperatures.  

    Code of Federal Regulations, 2013 CFR

    ...Limitation of external surface temperatures. 18.23 Section 18...ACCESSORIES Construction and Design Requirements § 18.23 Limitation of external surface temperatures. The temperature of the external surfaces...

    2013-07-01

    164

    Extraterrestrial Spectral Solar Irradiance Data for Modeling Spectral Solar Irradiance at the Earth's Surface.  

    National Technical Information Service (NTIS)

    This report describes the extraterrestrial (air mass zero, AMO) spectral solar irradiance data used by the Solar Energy Research Institute's Resource Assessment Branch in models to calculate spectral solar irradiance at the earth's surface. The report con...

    C. Riordan

    1987-01-01

    165

    Airborne Measurement of Microwave EmisSION FROM THE Earth's Surface and Atmosphere.  

    National Technical Information Service (NTIS)

    This paper reveals the results of a theoretical and experimental investigation of the microwave radiation emitted by the Earth's surface and atmosphere. The study objective was to evaluate the potential application of microwave radiometry to weather satel...

    H. A. Hyatt

    1965-01-01

    166

    Amplification of surface temperature trends and variability in thetropical atmosphere  

    SciTech Connect

    The month-to-month variability of tropical temperatures is larger in the troposphere than at the Earth's surface. This amplification behavior is similar in a range of observations and climate model simulations, and is consistent with basic theory. On multi-decadal timescales, tropospheric amplification of surface warming is a robust feature of model simulations, but occurs in only one observational dataset. Other observations show weak or even negative amplification. These results suggest that either different physical mechanisms control amplification processes on monthly and decadal timescales, and models fail to capture such behavior, or (more plausibly) that residual errors in several observational datasets used here affect their representation of long-term trends.

    Santer, B.D.; Wigley, T.M.L.; Mears, C.; Wentz, F.J.; Klein,S.A.; Seidel, D.J.; Taylor, K.E.; Thorne, P.W.; Wehner, M.F.; Gleckler,P.J.; Boyle, J.S.; Collins, W.D.; Dixon, K.W.; Doutriaux, C.; Free, M.; Fu, Q.; Hansen, J.E.; Jones, G.S.; Ruedy, R.; Karl, T.R.; Lanzante, J.R.; Meehl, G.A.; Ramaswamy, V.; Russell, G.; Schmidt, G.A.

    2005-08-11

    167

    Phytoplankton physiology can affect ocean surface temperatures  

    Microsoft Academic Search

    A key biological link between ocean geochemical cycles, ocean color and sea surface temperature (SST) is the nitrogen-to-chlorophyll a (N:chl a) ratio of phytoplankton. This is because nitrogen is the limiting factor over approximately 2\\/3 of the ocean surface and light absorption depends on the concentration of chlorophyll a. Recent work has demonstrated systematic variability in this ratio. Using one-dimensional

    Nathalie Lefèvre; Arnold H. Taylor; Richard J. Geider

    2001-01-01

    168

    Modelling global fresh surface water temperature  

    Microsoft Academic Search

    Temperature directly determines a range of water physical properties including vapour pressure, surface tension,\\u000adensity and viscosity, and the solubility of oxygen and other gases. Indirectly water temperature acts as a strong\\u000acontrol on fresh water biogeochemistry, influencing sediment concentration and transport, water quality parameters\\u000a(e.g. pH, nitrogen, phosphor, dissolved oxygen), chemical reaction rates, phytoplankton and zooplankton\\u000acomposition and the

    L. P. H. van Beek; T. Eikelboom; M. T. H. van Vliet; M. F. P. Bierkens

    2011-01-01

    169

    Contributions of surface fluid reservoirs of the late 90's anomaly of the Earth's oblateness  

    Microsoft Academic Search

    Recent satellite measurements have revealed a sudden change in the behaviour of the J2 (i.e. Earth's oblateness) time-series (Cox and Chao, 2002). Such an anomaly suggests an important redistribution of mass at the surface of the Earth from the high-latitude to the equatorial regions. In particular, air and water masse inside surface reservoirs (atmosphere, oceans, continental water storage -soil moisture,

    G. Ramillien; P. Soudant; A. Cazenave

    2003-01-01

    170

    Surface waves on periodic array of imperfectly conducting vertical dipoles over the flat earth  

    Microsoft Academic Search

    The theory is developed for surface waves on a periodic array of imperfectly conducting vertical dipoles over the flat earth. Expressions are presented for the surface-wave fields and for the transcendental equation whose root determines the complex propagation constant of the surface wave. Contour plots are included showing the attenuation constant and phase velocity as functions of dipole spacing and

    J. Richmond; R. Garbacz

    1979-01-01

    171

    The early phase of dielectric surface flashover in a simulated Low Earth Orbit environment  

    Microsoft Academic Search

    In Low Earth Orbit (LEO) the environment space plasma and UV radiation influences the surface charging and the surface flashover voltage of insulators, and thus the performance of high voltage systems. Understanding the mechanisms leading to surface flashover will make it possible to apply certain shielding techniques (e.g. electric and magnetic shielding) which can increase the dielectric flashover voltage drastically.

    F. Hegeler; H. Krompholz; I. L. Hatfield; M. Kristiansen

    1994-01-01

    172

    On the inhomogeneity of the transition surface layer of the solid core of the earth  

    SciTech Connect

    Different geophysical data and conclusions of theoretical models, which can give information about the behavior of the solid and liquid cores of the Earth as well as about the existence of a transition layer as a temperature-hysteresis region at a relatively weak first-order phase transition, are compared. It is concluded that liquid inclusions inevitably exist in this region; these inclusions are involved (due to the complex convective processes occurring in the liquid core) in the transport of light materials from some areas of the solid-core surface. The porosity and permeability of the transition layer determine the seismic acoustic inhomogeneities in these areas, which contact the convective flows in the liquid core. In particular, this explains the well-known 'east-west' effect. Obviously, the model of the crystalline core is not the only possible alternative for a model of a core with a metallic glasslike structure.

    Pikin, S. A., E-mail: pikin@ns.crys.ras.ru [Russian Academy of Sciences, Shubnikov Institute of Crystallography (Russian Federation)

    2012-05-15

    173

    Oxidation resistance of 9-12% Cr steels: effect of rare earth surface treatment  

    SciTech Connect

    Medium Cr steels have been used in fossil fired power plants for many years because of their excellent high temperature stability and mechanical properties. The environment in a fossil fired power plant is extremely aggressive in terms of corrosion, especially oxidation. This is only accelerated as the operating temperature increases to 650C and beyond. For any new steel to be qualified for power plant use, in addition to adequate strength at the operating temperature, material wastage from all corrosion processes must be kept to a minimum acceptable level. The use of medium Cr steels provides a means to improve overall corrosion resistance. Three medium Cr are under development for use as high temperature power plant steels: 0.08C-(9-12)Cr-1.2Ni-0.7Mo-3.0Cu-3.0Co-0.5Ti. Oxidation tests were performed on the steels for times greater than 1000 hours in order to determine the oxidation kinetics and extent of material wastage. Also, rare earth oxides were incorporated into the outer surface layers of the steels to see if the oxidation resistance could be improved. These results will be compared to current power plant steels.

    Dogan, Omer N.; Alman, David A.; Jablonski, Paul D.

    2005-02-01

    174

    DISAGGREGATION OF GOES LAND SURFACE TEMPERATURES USING SURFACE EMISSIVITY  

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Accurate temporal and spatial estimation of land surface temperatures (LST) is important for modeling the hydrological cycle at field to global scales because LSTs can improve estimates of soil moisture and evapotranspiration. Using remote sensing satellites, accurate LSTs could be routine, but unfo...

    175

    A Simple Downscaling Algorithm for Remotely Sensed Land Surface Temperature  

    NASA Astrophysics Data System (ADS)

    The method is illustrated using a combination of MODIS NDVI data with a spatial resolution of 250m and 3 Km Meteosat Second Generation SEVIRI LST data. Geostationary Earth Observation data carry a large potential for assessment of surface state variables. Not the least the European Meteosat Second Generation platform with its SEVIRI sensor is well suited for studies of the dynamics of land surfaces due to its high temporal frequency (15 minutes) and its red, Near Infrared (NIR) channels that provides vegetation indices, and its two split window channels in the thermal infrared for assessment of Land Surface Temperature (LST). For some applications the spatial resolution in geostationary data is too coarse. Due to the low statial resolution of 4.8 km at nadir for the SEVIRI sensor, a means of providing sub pixel information is sought for. By combining and properly scaling two types of satellite images, namely data from the MODIS sensor onboard the polar orbiting platforms TERRA and AQUA and the coarse resolution MSG-SEVIRI, we exploit the best from two worlds. The vegetation index/surface temperature space has been used in a vast number of studies for assessment of air temperature, soil moisture, dryness indices, evapotranspiration and for studies of land use change. In this paper, we present an improved method to derive a finer resolution Land Surface Temperature (LST). A new, deterministic scaling method has been applied, and is compared to existing deterministic downscaling methods based on LST and NDVI. We also compare our results from in situ measurements of LST from the Dahra test site in West Africa.

    Sandholt, I.; Nielsen, C.; Stisen, S.

    2009-05-01

    176

    A new model of snowball Earth; the core controlled the surface T of the Earth  

    Microsoft Academic Search

    Previous model The snowball Earth at 0.75-0.60 Ga and presumably at 2.3 Ga has been regarded as caused by decrease of greenhouse effect by atmospheric CO2. Probably not, we will show a new model. We present two new data sets to constraint the model. (1)Growth curve of continental crust by Pb-isotope age of river mouth zircon Growth rate of continental

    S. Maruyama; S. Rino; A. Yoshihara

    2005-01-01

    177

    Temperature coefficient of pyrographite surface free energy  

    Microsoft Academic Search

    By measuring the change in geometric parameters of cracks formed as a ; result of annealing, using the mathematical method of I. V. Obreimov, the ; temperature coefficient of free surface energy of basic-density pyrographite was ; measured in the interval 20 to 2300 deg C. (tr-auth);

    V. I. Kostikov; A. G. Kharitonov

    1972-01-01

    178

    22 Years of Sea Surface Temperatures  

    NSDL National Science Digital Library

    This NOAA visualization video on YouTube shows the seasonal variations in sea surface temperatures and ice cover for the 22 years prior to 2007 based on data collected by NOAA polar-orbiting satellites (POES). El NiÃo and La NiÃa are easily identified, as are the trends in decreasing polar sea ice.

    NOAA (National Oceanic and Atmospheric Administration) Visualizations

    179

    Monitoring global monthly mean surface temperatures  

    Microsoft Academic Search

    An assessment is made of how well the monthly mean surface temperatures for the decade of the 1980s are known. The sources of noise in the data, the numbers of observations, and the spatial coverage are appraised for comparison with the climate signal, and different analyzed results are compared to see how reproducible they are. The data are further evaluated

    Kevin E. Trenberth; J. W. Hurrell; J. R. Christy

    1992-01-01

    180

    Changes in biologically active ultraviolet radiation reaching the Earth's surface.  

    PubMed

    Since publication of the 1998 UNEP Assessment, there has been continued rapid expansion of the literature on UV-B radiation. Many measurements have demonstrated the inverse relationship between column ozone amount and UV radiation, and in a few cases long-term increases due to ozone decreases have been identified. The quantity, quality and availability of ground-based UV measurements relevant to assessing the environmental impacts of ozone changes continue to improve. Recent studies have contributed to delineating regional and temporal differences due to aerosols, clouds, and ozone. Improvements in radiative transfer modelling capability now enable more accurate characterization of clouds, snow-cover, and topographical effects. A standardized scale for reporting UV to the public has gained wide acceptance. There has been increased use of satellite data to estimate geographic variability and trends in UV. Progress has been made in assessing the utility of satellite retrievals of UV radiation by comparison with measurements at the Earth's surface. Global climatologies of UV radiation are now available on the Internet. Anthropogenic aerosols play a more important role in attenuating UV irradiances than has been assumed previously, and this will have implications for the accuracy of UV retrievals from satellite data. Progress has been made inferring historical levels of UV radiation using measurements of ozone (from satellites or from ground-based networks) in conjunction with measurements of total solar radiation obtained from extensive meteorological networks. We cannot yet be sure whether global ozone has reached a minimum. Atmospheric chlorine concentrations are beginning to decrease. However, bromine concentrations are still increasing. While these halogen concentrations remain high, the ozone layer remains vulnerable to further depletion from events such as volcanic eruptions that inject material into the stratosphere. Interactions between global warming and ozone depletion could delay ozone recovery by several years, and this topic remains an area of intense research interest. Future changes in greenhouse gases will affect the future evolution of ozone through chemical, radiative, and dynamic processes In this highly coupled system, an evaluation of the relative importance of these processes is difficult: studies are ongoing. A reliable assessment of these effects on total column ozone is limited by uncertainties in lower stratospheric response to these changes. At several sites, changes in UV differ from those expected from ozone changes alone, possibly as a result of long-term changes in aerosols, snow cover, or clouds. This indicates a possible interaction between climate change and UV radiation. Cloud reflectance measured by satellite has shown a long-term increase at some locations, especially in the Antarctic region, but also in Central Europe, which would tend to reduce the UV radiation. Even with the expected decreases in atmospheric chlorine, it will be several years before the beginning of an ozone recovery can be unambiguously identified at individual locations. Because UV-B is more variable than ozone, any identification of its recovery would be further delayed. PMID:12659535

    McKenzie, Richard L; Björn, Lars Olof; Bais, Alkiviadis; Ilyasad, Mohammad

    2003-01-01

    181

    Migration of air bubbles in ice under a temperature gradient, with application to “Snowball Earth  

    Microsoft Academic Search

    To help characterize the albedo of “sea glaciers” on Snowball Earth, a study of the migration rates of air bubbles in freshwater ice under a temperature gradient was carried out in the laboratory. The migration rates of air bubbles in both natural glacier ice and laboratory-grown ice were measured for temperatures between ?36°C and ?4°C and for bubble diameters of

    Ruzica Dadic; Bonnie Light; Stephen G. Warren

    2010-01-01

    182

    Temperature and concentration dependence of hydrogen site occupancy in several rare-earth dihydrides  

    NASA Astrophysics Data System (ADS)

    Neutron inelastic scattering and diffraction techniques are used to study the hydrogen site distribution in several rare earth dihydrides as a function of temperature and concentration. For Y, La, and Ce the fraction of hydrogen on octahedral sites is approximately a constant from 15K to 200K followed by a decrease with increasing temperature. A model is presented which qualitatively explains this behavior.

    Goldstone, J. A.; Eckert, J.; Richards, P. M.; Venturini, E. L.

    183

    Temperature and concentration dependence of hydrogen site occupancy in several rare-earth dihydrides  

    SciTech Connect

    Neutron inelastic scattering and diffraction techniques were used to study the hydrogen site distribution in several rare earth dihydrides as a function of temperature and concentration. For Y, La, and Ce the fraction of hydrogen on octahedral sites is approximately a constant from 15K to 200K followed by a decrease with increasing temperature. A model is presented which qualitatively explains this behavior.

    Goldstone, J.A.; Eckert, J.; Richards, P.M.; Venturini, E.L.

    1985-01-01

    184

    Evaluation of Earth's atmospheric brightness temperature at decimetric wavelengths  

    NASA Astrophysics Data System (ADS)

    Atmospheric profiles of pressure, temperature, and relative humidity, measured with stratospheric balloons, are used to calculate the radiofrequency brightness temperature, Tatm, of the atmospheric signal seen by a ground observer. Below 1 GHz the calculated values are definitely more precise (few percent accuracy), than directly measured values (10% accuracy or worse).

    Ajello, C.; Bonelli, G.; Sironi, G.

    1995-02-01

    185

    Low Temperature Effects: Surface Mount Capacitors  

    SciTech Connect

    The low signal to noise ratio produced by the VLPC (Visible Light Photon Counter) chip in the detection of a single photon necessitates the use of a filtering capacitor. Maximum performance of the filtering capabilities dictate the placement of the capacitor be as close to the VLPC chip as possible. However, the chip operates at extremely low temperatures (7K). In addition, available space within the VLPC cassette is limited. Therefore it is desired to find a capacitor which provides good temperature stability at cryogenic temperatures within a minimal space (e.g. surface mounted). This engineering note presents the results from a test of the effect of low temperature on surface mounted capacitors. Preliminary testing suggested that capacitors of the tantalum type would provide the best te mperature stability at cryogenic temperatures, therefore two different tantalum capacitors were tested. A ceramic capacitor was also included in the results as a comparison, even though preliminary results suggested the ceramic type would not provide sufficient temperature stability.

    Clark, D.; /Fermilab

    1992-08-17

    186

    Accurate measurement of LED lens surface temperature  

    NASA Astrophysics Data System (ADS)

    Radiant power emitted by high power light-emitting diodes (LEDs) have been steadily increasing over the past decade. High radiation, especially short wavelength, can increase the temperature and negatively affect the primary lens performance of high-power LEDs. In this regards, assessment of lens temperature during operation is important. Past studies have shown large errors when thermocouples are used for measuring temperature in high radiant flux environments. Therefore, the objective of this study was to understand the problem in using thermocouples to measure LED lens surface temperature and to find a solution to improving the measurement accuracy. A laboratory study was conducted to better understand the issue. Results showed that most of the error is due to absorption of visible radiant energy by the thermocouple. In this study, the measurements made using an infrared (IR) thermal imaging system were used as the reference temperature because the IR imaging system is unaffected by radiant flux in the visible range. After studying the thermocouple wire metallurgy and its radiation absorption properties, a suitable material was identified to shield the thermocouple from visible radiation. Additionally, a silicone elastomer was used to maintain the thermal interface between the lens surface and the thermocouple junction bead. With these precautions, the lens temperature measurements made using the J-type thermocouple and the IR imaging system matched very well.

    Perera, Indika U.; Narendran, Nadarajah; Liu, Yi-wei

    2013-09-01

    187

    Low Temperature Resistivity of Yttrium-Based Alloys Containing Small Amounts of Rare Earth Metals  

    Microsoft Academic Search

    The resistivity of the dilute alloys of rare earth metals with yttrium has been measured at low temperatures. The result is in qualitative agreement with the recent theories due to Kondo and others on the s--d or s--f scattering. The effective s--f exchange integrals for various rare-earth solutes have been derived from the analysis of the resistivity data and compared

    Tadashi Sugawara

    1965-01-01

    188

    Global modeling of fresh surface water temperature  

    NASA Astrophysics Data System (ADS)

    Temperature determines a range of water physical properties, the solubility of oxygen and other gases and acts as a strong control on fresh water biogeochemistry, influencing chemical reaction rates, phytoplankton and zooplankton composition and the presence or absence of pathogens. Thus, in freshwater ecosystems the thermal regime affects the geographical distribution of aquatic species through their growth and metabolism, tolerance to parasites, diseases and pollution and life history. Compared to statistical approaches, physically-based models of surface water temperature have the advantage that they are robust in light of changes in flow regime, river morphology, radiation balance and upstream hydrology. Such models are therefore better suited for projecting the effects of global change on water temperature. Till now, physically-based models have only been applied to well-defined fresh water bodies of limited size (e.g., lakes or stream segments), where the numerous parameters can be measured or otherwise established, whereas attempts to model water temperature over larger scales has thus far been limited to regression type of models. Here, we present a first attempt to apply a physically-based model of global fresh surface water temperature. The model adds a surface water energy balance to river discharge modelled by the global hydrological model PCR-GLOBWB. In addition to advection of energy from direct precipitation, runoff and lateral exchange along the drainage network, energy is exchanged between the water body and the atmosphere by short and long-wave radiation and sensible and latent heat fluxes. Also included are ice-formation and its effect on heat storage and river hydraulics. We used the coupled surface water and energy balance model to simulate global fresh surface water temperature at daily time steps on a 0.5x0.5 degree grid for the period 1970-2000. Meteorological forcing was obtained from the CRU data set, downscaled to daily values with ECMWF ERA40 re-analysis data. We compared our simulation results with daily temperature data from rivers and lakes (USGS, limited to the USA) and compared mean monthly temperatures with those recorded in the GEMS data set. Results show that the model is able to capture well the mean monthly surface temperature for the majority of the GEMS stations both in time as well as in space, while the inter-annual variability as derived from the USGS data was captured reasonably well. Results are poorest for the arctic rivers, possibly because the timing of ice-breakup is predicted too late in the year due to the lack of including a mechanical break-up mechanism. The spatio-temporal variation of water temperature reveals large temperature differences between water and atmosphere for the higher latitudes, while considerable lateral transport of heat can be observed for rivers crossing hydroclimatic zones such as the Nile, the Mississippi and the large rivers flowing into the Arctic. Overall, our model results show great promise for future projection of global fresh surface water temperature under global change.

    Bierkens, M. F.; Eikelboom, T.; van Vliet, M. T.; Van Beek, L. P.

    2011-12-01

    189

    Land surface modeling and satellite passive microwave imagery: a comparison of top soil moisture and surface temperature estimates  

    NASA Astrophysics Data System (ADS)

    Improved accuracy in defining initial conditions for fully-coupled numerical weather prediction models (NWP) along with continuous internal bias corrections for baseline data generated by uncoupled Land Surface Models (LSM), is expected to lead to improved short-term to long-range weather forecasting capability. Because land surface parameters are highly integrated states, errors in land surface forcing, model physics and parameterization tend to accumulate in the land surface stores of these models, such as soil moisture and surface temperature. This has a direct effect on the model's water and energy balance calculations, and will eventually result in inaccurate weather predictions. Surface soil moisture and surface temperature estimates obtained with a recently improved retrieval algorithm from the Advanced Microwave Scanner Radiometer (AMSR) aboard NASA's Earth Observing System (EOS) Aqua satellite are evaluated against model output of the Community Noah Land Surface Model operated within the Land Information System (LIS) forced with atmospheric data of the NCEP Global Data Assimilation System (GDAS). The surface temperature retrievals and Noah LSM output are further evaluated against local measurements from the Mesonet observational grid in Oklahoma. Preliminary analysis presented here shows a potential to improve simulated surface temperature estimates of the Noah model by assimilating satellite derived surface temperature fields. The potential for updating (top) soil moisture seems to be more restricted, mainly as a result of the relatively thick top soil layer of the model as compared to the passive microwave emanation depth.

    Gouweleeuw, B.; Owe, M.; Holmes, T.

    2006-10-01

    190

    Monitoring global monthly mean surface temperatures  

    SciTech Connect

    An assessment is made of how well the monthly mean surface temperatures for the decade of the 1980s are known. The sources of noise in the data, the numbers of observations, and the spatial coverage are appraised for comparison with the climate signal, and different analyzed results are compared to see how reproducible they are. The data are further evaluated by comparing anomalies of near-global monthly mean surface temperatures with those of global satellite channel 2 microwave sounding unit (MSU) temperatures for 144 months from 1979 to 1990. Very distincitve patterns are seen in the correlation coefficients, which range from high (> 0.8) over the extratropical continents of the Northern Hemisphere, to moderate ([approximately] 0.5) over tropical and subtropical land areas, to very low over the southern oceans and tropical western Pacific. The physical difference between the two temperature measurements is one factor in these patterns. The correlation coefficient is a measure of the signal-to-noise ratio, and largest values are found where the climate signal is largest, but the spatial variation in the inherent noise in the surface observations over the oceans is the other major factor in accounting for the pattern. 42 refs., 12 figs., 4 tab.

    Trenberth, K.E.; Hurrell, J.W. (National Center for Atmospheric Research, Boulder, CO (United States)); Christy, J.R. (Univ. of Alabama in Huntsville (United States))

    1992-12-01

    191

    Rashba effect at the surfaces of rare-earth metals and their monoxides  

    Microsoft Academic Search

    We present a systematic study of the Rashba-type spin-orbit interaction at the (0001) surfaces of rare-earth metals and their surface monoxides, specifically of Tb metal and the O\\/Tb, O\\/Lu and O\\/Y surfaces. By means of photoemission experiments and ab initio band-structure calculations, we uncover the influence of this interaction on the surface electronic structure. In turn, the dramatic impact of

    O. Krupin; G. Bihlmayer; K. M. Döbrich; J. E. Prieto; K. Starke; S. Gorovikov; S. Blügel; S. Kevan; G. Kaindl

    2009-01-01

    192

    Low-temperature preparation of ultrafine rare-earth iron garnets  

    SciTech Connect

    Ultrafine rare-earth iron garnets, (R{sub 3}Fe{sub 5}O{sub 12} where R = Sm, Tb, Dy, Ho, Er, Yb, (YGd), and (YNd)) have been prepared by thermal decomposition of a citrate precursor, R{sub 3}Fe{sub 5}(cit){sub 25} {center dot} (36 + N)H{sub 2}O. The precursors decompose at lower temperatures, below 450{degrees}C, and are characterized using DTA, DSC, TG, and IR spectroscopy. Ultrafine amorphous garnets having particle size 10 to 35 nm and surface area 30 to 75 m{sup 2}/g have been obtained and characterized by XRD, TEM, Mossbauer spectra, particle size analysis, and magnetic and surface area measurements. Superparamagnetism indicates the ultrafine characteristics of the garnet materials. The nature of crystallite aggregates and agglomerates is of special interest because it represents finite clusters. An intercrystallite bond exists between crystallites having 1.0- to 1.5-nm size. The rupture of intercrystallite bonds during crystallization leads to monolith formation.

    Sankaranarayanan, V.K.; Gajbhiye, N.S. (Dept. of Chemistry, Indian Institute of Technology, Kanpur (IN))

    1990-05-01

    193

    Influence of 4f electronic states on the surface states of rare-earth hexaborides  

    NASA Astrophysics Data System (ADS)

    We study the surface electronic structure of a series of rare-earth hexaborides using state-of-the-art high resolution photoemission spectroscopy. Experimental results reveal a surface state around 1.8 eV binding energy in all the hexaborides indicating its generic nature in this class of compounds. The surface and bulk electronic structures near the Fermi level, ?F are almost similar in each of the compounds. This suggests an interesting possibility of fabricating new materials possessing low work function like LaB6 where the behavior of mobile electrons can be tuned by rare-earth substitutions.

    Patil, Swapnil; Adhikary, Ganesh; Balakrishnan, Geetha; Maiti, Kalobaran

    2010-03-01

    194

    Orientation of artificial surfaces relative to directions toward the sun and artificial earth satellites  

    Microsoft Academic Search

    Formulas are derived for determination of azimuths and zenith distances of directions toward the sun and a satellite, the normal to the surface of a flat mirror at a point in time at which a reflected solar ray crosses the center of mass of the satellite. The expressions use geodesic coordinates of a point on the earth surface and satellite

    V. R. Golovchin

    1984-01-01

    195

    Migration of air bubbles in ice under a temperature gradient, with application to “Snowball Earth  

    NASA Astrophysics Data System (ADS)

    To help characterize the albedo of "sea glaciers" on Snowball Earth, a study of the migration rates of air bubbles in freshwater ice under a temperature gradient was carried out in the laboratory. The migration rates of air bubbles in both natural glacier ice and laboratory-grown ice were measured for temperatures between -36°C and -4°C and for bubble diameters of 23-2000 ?m. The glacier ice was sampled from a depth near close-off (74 m) in the JEMS2 ice core from Summit, Greenland. Migration rates were measured by positioning thick sections of ice on a temperature gradient stage mounted on a microscope inside a freezer laboratory. The maximum and minimum migration rates were 5.45 ?m h-1 (K cm-1)-1 at -4°C and 0.03 ?m h-1 (K cm-1)-1 at -36°C. Besides a strong dependence on temperature, migration rates were found to be proportional to bubble size. We think that this is due to the internal air pressure within the bubbles, which may correlate with time since close-off and therefore with bubble size. Migration rates show no significant dependence on bubble shape. Estimates of migration rates computed as a function of bubble depth within sea glaciers indicate that the rates would be low relative to the predicted sublimation rates, such that the ice surface would not lose its air bubbles to net downward migration. It is therefore unlikely that air bubble migration could outrun the advancing sublimation front, transforming glacial ice to a nearly bubble-free ice type, analogous to low-albedo marine ice.

    Dadic, Ruzica; Light, Bonnie; Warren, Stephen G.

    2010-09-01

    196

    Tunguska phenomenon: Discharge processes near the earth's surface  

    NASA Astrophysics Data System (ADS)

    An investigation of the Tunguska cosmic body's epicenter showed that both dried trees and those that survived the catastrophe are marked with characteristic deteriorations. For the trees that survived near the epicenter (the distance is <4 km), cracks of up to 7 m in length are found on their stems. All the vegetation near the explosion epicenter has traces of uniform scorch that covered the trees even on the land parts isolated by water. On the background of this uniform scorch, a notable feature is carbonization that touched the tree tops and the earth-directed ends of broken branches. All tops of both living and dried trees in the central zone are burned and dead. Carbonization of tops and branch ends was observed up to a distance of 10-15 km from the epicenter; i.e., charge processes took place over an area of more than 500 km2 in size. Carbonized branch ends have a characteristic "bird's nail" shape, which has no analogs on the Earth. Similar deterioration is typical for the crater shape that obtains an anode during arc discharge combustion. It is supposed that the duration of these charge processes could be ?1 min.

    Gladysheva, O. G.

    2013-09-01

    197

    Martian Meteorites Record Surface Temperatures on Mars  

    NSDL National Science Digital Library

    This site from Planetary Science Research Discoveries at the University of Hawaii uses recent research on using the ages of Martian meteorites to explore the history of surface temperature on Mars. Results of geochemical analyses from two very different meteorites indicate that Mars has experienced only very brief warm, wet periods during the past 4 billion years. Photographs, satellite images, thin sections, and graphs help illustrate the research.

    Taylor, G. J.; Planetary Science Research Discoveries, University O.

    198

    Temporal Variations in Sea Surface Topography and Dynamics of the Earth's Inertia Ellipsoid  

    Microsoft Academic Search

    Temporal variations in the nine elements of the Earth's inertia ellipsoid due to sea surface topography dynamics were derived from TOPEX\\/POSEIDON altimeter data 1993 - 1996. The variations amount to about 10 mm in the position of the center of the Earth's inertia ellipsoid (Ei), 0.15'' in the polar axis direction of Eiand to about 0.0003 in the denominator of

    Milan Burša; Jan Kouba; Karel Rad?j; Scott A. True; Viliam Vatrt; Marie Vojtíšková

    1999-01-01

    199

    Real-time Google Earth 3D assisted driving system in surface mining operations  

    Microsoft Academic Search

    To improve the mine haul trucks operating safety in surface mining, a novel driving assisted system based on the GPS, mesh-wireless networks, and the Google-Earth API was developed. It has the capability to pin-point and track vehicles in real time using a 3D interface, which is based on user-based AutoCAD mine maps using the Google-Earth graphics interface. The research results

    Enji Sun; Antonio Nieto; Zhongxue Li

    2009-01-01

    200

    High temperature low friction surface coating  

    DOEpatents

    A high temperature, low friction, flexible coating for metal surfaces which are subject to rubbing contact includes a mixture of three parts graphite and one part cadmium oxide, ball milled in water for four hours, then mixed with thirty percent by weight of sodium silicate in water solution and a few drops of wetting agent. The mixture is sprayed 12-15 microns thick onto an electro-etched metal surface and air dried for thirty minutes, then baked for two hours at 65.degree. C. to remove the water and wetting agent, and baked for an additional eight hours at about 150.degree. C. to produce the optimum bond with the metal surface. The coating is afterwards burnished to a thickness of about 7-10 microns.

    Bhushan, Bharat (Watervliet, NY)

    1980-01-01

    201

    The impact of land surface temperature on soil moisture anomaly detection from passive microwave observations  

    NASA Astrophysics Data System (ADS)

    For several years passive microwave observations have been used to retrieve soil moisture from the Earth's surface. Low frequency observations have the most sensitivity to soil moisture, therefore the current Soil Moisture and Ocean Salinity (SMOS) and future Soil Moisture Active and Passive (SMAP) satellite missions observe the Earth's surface in the L-band frequency. In the past, several satellite sensors such as the Advanced Microwave Scanning Radiometer-EOS (AMSR-E) and WindSat have been used to retrieve surface soil moisture using multi-channel observations obtained at higher microwave frequencies. While AMSR-E and WindSat lack an L-band channel, they are able to leverage multi-channel microwave observations to estimate additional land surface parameters. In particular, the availability of Ka-band observations allows AMSR-E and WindSat to obtain coincident surface temperature estimates required for the retrieval of surface soil moisture. In contrast, SMOS and SMAP carry only a single frequency radiometer and therefore lack an instrument suited to estimate the physical temperature of the Earth. Instead, soil moisture algorithms from these new generation satellites rely on ancillary sources of surface temperature (e.g. re-analysis or near real time data from weather prediction centres). A consequence of relying on such ancillary data is the need for temporal and spatial interpolation, which may introduce uncertainties. Here, two newly-developed, large-scale soil moisture evaluation techniques, the triple collocation (TC) approach and the Rvalue data assimilation approach, are applied to quantify the global-scale impact of replacing Ka-band based surface temperature retrievals with Modern Era Retrospective-analysis for Research and Applications (MERRA) surface temperature output on the accuracy of WindSat and AMSR-E based surface soil moisture retrievals. Results demonstrate that under sparsely vegetated conditions, the use of MERRA land surface temperature instead of Ka-band radiometric land surface temperature leads to a relative decrease in skill (on average 9.7%) of soil moisture anomaly estimates. However the situation is reversed for highly vegetated conditions where soil moisture anomaly estimates show a relative increase in skill (on average 13.7%) when using MERRA land surface temperature. In addition, a pre-processing technique to shift phase of the modelled surface temperature is shown to generally enhance the value of MERRA surface temperature estimates for soil moisture retrieval. Finally, a very high correlation (R2 = 0.95) and consistency between the two evaluation techniques lends further credibility to the obtained results.

    Parinussa, R. M.; Holmes, T. R. H.; Yilmaz, M. T.; Crow, W. T.

    2011-10-01

    202

    Impact of Atlantic sea surface temperatures on the warmest global surface air temperature of 1998  

    Microsoft Academic Search

    The year 1998 is the warmest year in the record of instrumental measurements. In this study, an atmospheric general circulation model is used to investigate the role of sea surface temperatures (SSTs) in this warmth, with a focus on the role of the Atlantic Ocean. The model forced with the observed global SSTs captures the main features of land surface

    Riyu Lu

    2005-01-01

    203

    Effects of cosmic rays on the Earth's surface applied to space radiation biology  

    NASA Astrophysics Data System (ADS)

    Our research demonstrated that secondary cosmic rays and variations of the geomagnetic field on the Earth s surface could be essential in determining the situation on the board of a spacecraft and the state of different biological objects The biological systems on the Earth s surface are shielded by the atmosphere against the general damaging effects of geocosmical agents However the exposure of biosystems to secondary cosmic rays during the great solar particle events at high latitude could be comparable with the exposure to cosmic rays on the board of a space station during a quiet period Hence the genetic effects in cell systems induced by their exposure to secondary cosmic rays during great solar events near the Earth s surface could be same as it in space Our experiments on cell cultures carried out during the great solar particle events in October 1989 at high latitude have demonstrated extraordinary phenomena associated with destructions of cellular nuclei DNA and chromosomes which were found in cell cultures The observed effects coincided with an increase of solar high energetic particles in the near Earth s space and an increase of the neutron count rate near the Earth s surface Similar phenomena were also found during experiments on the board of spacecraft in the near Earth orbit There is reason to believe that consequences of a super events in SCR for genetic matter of biological objects during space exploration should be at least not less pronounced than at the near Earth s surface The effects of geocosmical agents on the

    Belisheva, N. K.; Lammer, H.; Biernat, H. K.; Tsetlin, V. V.; Vinnichenko, M. B.; Getselev, I. V.

    204

    Solar variability and climate change: Geomagnetic aa index and global surface temperature  

    Microsoft Academic Search

    During the past ?120 years, Earth's surface temperature is correlated with both decadal averages and solar cycle minimum values of the geomagnetic aa index. The correlation with aa minimum values suggests the existence of a long-term (low-frequency) component of solar irradiance that underlies the 11-year cyclic component. Extrapolating the aa-temperature correlations to Maunder Minimum geomagnetic conditions implies that solar forcing

    E. W. Clivernd; V. Boriakoff; J. Feynman

    1998-01-01

    205

    Validation of the land-surface temperature products retrieved from Terra Moderate Resolution Imaging Spectroradiometer data  

    Microsoft Academic Search

    This paper presents the status of land-surface temperature (LST) standard products retrieved from Earth Observing System (EOS) Moderate Resolution Imaging Spectroradiometer (MODIS) data. Based on estimates of the channel-dependence error and noise equivalent temperature difference (NEDT) and the calibration accuracy of MODIS thermal–infrared data, the impact of instrument performance on the accuracy of LST is discussed. A double-screen scheme based

    Zhengming Wan; Yulin Zhang; Qincheng Zhang; Zhao-liang Li

    2002-01-01

    206

    Bulk and surface electronic structure of actinide, rare earth, and transition metal elements and compounds  

    SciTech Connect

    This is the final report for a three-year, Laboratory Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). This project sought to study of unusual magnetic and structural properties of rare earth, actinide, and transition metals through high-precision electronic structure calculations. Magnetic moment anisotropies in bulk and surface systems were studied, with emphasis on novel surfaces with unusual magnetic properties with possible applicability in magnetic recording. The structural stability, bonding properties, and elastic response of the actinides, as well as transition and rare earth elements and compounds, were also studied. The project sought to understand the unusual crystallographic and cohesive properties of the actinides and the importance of correlation to structural stability and the nature of the delocalization transition in these elements. Theoretical photoemission spectra, including surface effects, were calculated for rare earths and actinides.

    Wills, J.W.; Eriksson, O.

    1996-07-01

    207

    The international surface temperature initiative's global land surface databank  

    NASA Astrophysics Data System (ADS)

    The International Surface Temperature Initiative (ISTI) consists of an end-to-end process for land surface air temperature analyses. The foundation is the establishment of a global land surface Databank. This builds upon the groundbreaking efforts of scientists in the 1980s and 1990s. While using many of their principles, a primary aim is to improve aspects including data provenance, version control, openness and transparency, temporal and spatial coverage, and improved methods for merging disparate sources. The initial focus is on daily and monthly timescales. A Databank Working Group is focused on establishing Stage-0 (original observation forms) through Stage-3 data (merged dataset without quality control). More than 35 sources of data have already been added and efforts have now turned to development of the initial version of the merged dataset. Methods have been established for ensuring to the extent possible the provenance of all data from the point of observation through all intermediate steps to final archive and access. Databank submission procedures were designed to make the process of contributing data as easy as possible. All data are provided openly and without charge. We encourage the use of these data and feedback from interested users.

    Lawrimore, J. H.; Rennie, J.; Gambi de Almeida, W.; Christy, J.; Flannery, M.; Gleason, B.; Klein-Tank, A.; Mhanda, A.; Ishihara, K.; Lister, D.; Menne, M. J.; Razuvaev, V.; Renom, M.; Rusticucci, M.; Tandy, J.; Thorne, P. W.; Worley, S.

    2013-09-01

    208

    Global trends of measured surface air temperature  

    NASA Astrophysics Data System (ADS)

    We analyze surface air temperature data from available meteorological stations with principal focus on the period 1880-1985. The temperature changes at mid- and high latitude stations separated by less than 1000 km are shown to be highly correlated; at low latitudes the correlation falls off more rapidly with distance for nearby stations. We combine the station data in a way which is designed to provide accurate long-term variations. Error estimates are based in part on studies of how accurately the actual station distributions are able to reproduce temperature change in a global data set produced by a three-dimensional general circulation model with realistic variability. We find that meaningful global temperature change can be obtained for the past century, despite the fact that the meteorological stations are confined mainly to continental and island locations. The results indicate a global warming of about 0.5°-0.7°C in the past century, with warming of similar magnitude in both hemispheres; the northern hemisphere result is similar to that found by several other investigators. A strong warming trend between 1965 and 1980 raised the global mean temperature in 1980 and 1981 to the highest level in the period of instrumental records. The warm period in recent years differs qualitatively from the earlier warm period centered about 1940; the earlier warming was focused at high northern latitudes, while the recent warming is more global. We present selected graphs and maps of the temperature change in each of the eight latitude zones. A computer tape of the derived regional and global temperature changes is available from the authors.

    Hansen, James; Lebedeff, Sergej

    1987-11-01

    209

    Diurnal Relationship Between the Surface Albedo and Surface Temperature in Revegetated Desert Ecosystems, Northwestern China  

    Microsoft Academic Search

    Quantification of the relationship between surface albedo and surface temperature was done by analyzing measured diurnal variations of surface albedo and surface temperature on the biological soil crusts and sand dunes within vegetation-stabilized desert ecosystems. The surface albedos and surface temperatures of sand dunes and biological soil crusts were measured concurrently over field plots of the moving sand area and

    Ya-Feng Zhang; Xin-Ping Wang; Yan-Xia Pan; Rui Hu

    2012-01-01

    210

    Surface temperatures of insulated glazing units: Infrared thermography laboratory measurements  

    Microsoft Academic Search

    Data are presented for the distribution of surface temperatures on the warm-side surface of seven different insulated glazing units. Surface temperatures are measured using infrared thermography and an external referencing technique. This technique allows detailed mapping of surface temperatures that is non-intrusive. The glazings were placed between warm and cold environmental chambers that were operated at conditions corresponding to standard

    Brent T. Griffith; D. Tuerler; Dariush Arasteh

    1995-01-01

    211

    Sea surface temperature cooling mode in the Pacific cold tongue  

    Microsoft Academic Search

    Long-term variability in sea surface temperature (SST) in the equatorial Pacific and its relationship with global warming were investigated using three SST data sets (Hadley Center Global Sea Ice and Sea Surface Temperature, extended reconstruction sea surface temperature, and Kaplan), atmospheric fields from National Centers for Environmental Prediction\\/National Center for Atmospheric Research reanalysis, and subsurface sea temperature from the Simple

    Wenjun Zhang; Jianping Li; Xia Zhao

    2010-01-01

    212

    Temperature of cold ions in the night-time sector of the Earth's plasmasphere  

    Microsoft Academic Search

    The thermal structure of night-time plasmasphere is examined on the basis of some results of measurements of the distribution of concentration np and temperatures Tp of cold plasma in the Earth's plasmasphere. The results were obtained aboard the SA \\

    V. Bezrukikh; G. Kotova; M. Verigin; J. Smilauer; Yu. Venediktov; N. Barabanov

    2007-01-01

    213

    Black Body Temperature in Terms of Earth's Orbital Elements and the Milankovitch Precession Index  

    Microsoft Academic Search

    The temperature T of a black or gray body orbiting the Sun can be expressed in terms of spherical harmonics in latitude and longitude, its Keplerian orbital elements, and a variable describing rotation about its axis. Assuming that the Earth is a gray body, the resulting equation for T exhibits previously unrecognized odd-degree zonal terms dubbed \\

    D. P. Rubincam

    2002-01-01

    214

    Evidence for a High Temperature Differentiation in a Molten Earth: A Preliminary Appraisal.  

    National Technical Information Service (NTIS)

    If the earth were molten during its later stages of accretion as indicated by the present understanding of planetary accretion process, the differentiation that led to the formation of the core and mantle must have occurred at high temperatures in the ran...

    V. R. Murthy

    1992-01-01

    215

    High-temperature electrical resistivity of rare-earth metals with variable valence  

    SciTech Connect

    The electrical resistivity of compounds of rare-earth metals at high temperatures is calculated on the basis of allowance for the background mechanism of scattering and the hybridization of local electron states with the states of conduction electrons. An analytic expression is obtained for resistivity in a strong hybridization approximation. It follows from the expression that electrical resistivity may have a negative temperature coefficient within a broad range of high temperatures. The use of a three-band (s, d, f) model makes it possible to explain experimental data on the resistivity of certain rare-earth metals, particularly the connection between the sign of the temperature coefficient of electrical resistivity and the curvature of the relation (T).

    Povzner, A.A.; Abel'skii, S.S.

    1986-11-01

    216

    Sea surface temperature variability: patterns and mechanisms.  

    PubMed

    Patterns of sea surface temperature (SST) variability on interannual and longer timescales result from a combination of atmospheric and oceanic processes. These SST anomaly patterns may be due to intrinsic modes of atmospheric circulation variability that imprint themselves upon the SST field mainly via surface energy fluxes. Examples include SST fluctuations in the Southern Ocean associated with the Southern Annular Mode, a tripolar pattern of SST anomalies in the North Atlantic associated with the North Atlantic Oscillation, and a pan-Pacific mode known as the Pacific Decadal Oscillation (with additional contributions from oceanic processes). They may also result from coupled ocean-atmosphere interactions, such as the El Niño-Southern Oscillation phenomenon in the tropical Indo-Pacific, the tropical Atlantic Niño, and the cross-equatorial meridional modes in the tropical Pacific and Atlantic. Finally, patterns of SST variability may arise from intrinsic oceanic modes, notably the Atlantic Multidecadal Oscillation. PMID:21141660

    Deser, Clara; Alexander, Michael A; Xie, Shang-Ping; Phillips, Adam S

    2010-01-01

    217

    A global monthly sea surface temperature climatology  

    SciTech Connect

    The paper presents a new global 2 deg x 2 deg monthly sea surface temperature (SST) climatology, referred here to as the Shea-Trenberth-Reynolds (STR) climatology, which was derived by modifying a 1950-1979-based SST climatology from the Climate Analysis Center (CAC), by using data from the Comprehensive Ocean-Atmosphere Data Set to improve the SST estimates in the regions of the Kuroshio and the Gulf Stream. A comparison of the STR climatology with the Alexander and Mobley SST climatology showed that the STR climatology is warmer in the Northern Hemisphere, and colder poleward of 45 deg S. 22 refs.

    Shea, D.J.; Trenberth, K.E.; Reynolds, R.W. (NCAR, Boulder, CO (United States) NOAA, Climate Analysis Center, Washington, DC (United States))

    1992-09-01

    218

    Mapping permeability over the surface of the Earth  

    USGS Publications Warehouse

    Permeability, the ease of fluid flow through porous rocks and soils, is a fundamental but often poorly quantified component in the analysis of regional-scale water fluxes. Permeability is difficult to quantify because it varies over more than 13 orders of magnitude and is heterogeneous and dependent on flow direction. Indeed, at the regional scale, maps of permeability only exist for soil to depths of 1-2 m. Here we use an extensive compilation of results from hydrogeologic models to show that regional-scale (>5 km) permeability of consolidated and unconsolidated geologic units below soil horizons (hydrolithologies) can be characterized in a statistically meaningful way. The representative permeabilities of these hydrolithologies are used to map the distribution of near-surface (on the order of 100 m depth) permeability globally and over North America. The distribution of each hydrolithology is generally scale independent. The near-surface mean permeability is of the order of ???5 ?? 10-14 m2. The results provide the first global picture of near-surface permeability and will be of particular value for evaluating global water resources and modeling the influence of climate-surface-subsurface interactions on global climate change. Copyright ?? 2011 by the American Geophysical Union.

    Gleeson, T.; Smith, L.; Moosdorf, N.; Hartmann, J.; Durr, H. H.; Manning, A. H.; Van Beek, L. P. H.; Jellinek, A. M.

    2011-01-01

    219

    Mapping permeability over the surface of the Earth  

    USGS Publications Warehouse

    Permeability, the ease of fluid flow through porous rocks and soils, is a fundamental but often poorly quantified component in the analysis of regional-scale water fluxes. Permeability is difficult to quantify because it varies over more than 13 orders of magnitude and is heterogeneous and dependent on flow direction. Indeed, at the regional scale, maps of permeability only exist for soil to depths of 1-2 m. Here we use an extensive compilation of results from hydrogeologic models to show that regional-scale (>5 km) permeability of consolidated and unconsolidated geologic units below soil horizons (hydrolithologies) can be characterized in a statistically meaningful way. The representative permeabilities of these hydrolithologies are used to map the distribution of near-surface (on the order of 100 m depth) permeability globally and over North America. The distribution of each hydrolithology is generally scale independent. The near-surface mean permeability is of the order of -5 x 10-14 m2. The results provide the first global picture of near-surface permeability and will be of particular value for evaluating global water resources and modeling the influence of climate-surface-subsurface interactions on global climate change.

    Gleeson, Tom; Smith, Leslie; Moosdorf, Nils; Hartmann, Jens; Durr, Hans H.; Manning, Andrew H.; van Beek, Ludovicus P. H.; Jellinek, A. M.

    2011-01-01

    220

    Dielectric surface flashover in a simulated low Earth orbit environment  

    Microsoft Academic Search

    Surface flashover on insulators under UV irradiation or with a plasma background was investigated with high-speed electrical and optical sensors in order to clarify differences in the breakdown development compared to the pure vacuum case. Results with a plasma background show a more rapid development in the breakdown initiation compared to measurements in vacuum with no plasma. With a magnetic

    FRANK HEGELER; Hermann G. Krompholz; L. L. Hatfield; M. Kristiansen

    1997-01-01

    221

    Rare earth chalcogenides for use as high temperature thermoelectric materials  

    SciTech Connect

    In the first part of the thesis, the electric resistivity, Seebeck coefficient, and Hall effect were measured in X{sub y}(Y{sub 2}S{sub 3}){sub 1-y} (X = Cu, B, or Al), for y = 0.05 (Cu, B) or 0.025-0.075 for Al, in order to determine their potential as high- temperature (HT)(300-1000 C) thermoelectrics. Results indicate that Cu, B, Al- doped Y{sub 2}S{sub 3} are not useful as HT thermoelectrics. In the second part, phase stability of {gamma}-cubic LaSe{sub 1.47-1.48} and NdSe{sub 1.47} was measured periodically during annealing at 800 or 1000 C for the same purpose. In the Nd selenide, {beta} phase increased with time, while the Nd selenide showed no sign of this second phase. It is concluded that the La selenide is not promising for use as HT thermoelectric due to the {gamma}-to-{beta} transformation, whereas the Nd selenide is promising.

    Michiels, J.

    1996-01-02

    222

    Surface-atmosphere interactions on Titan compared with those on the pre-biotic Earth.  

    PubMed

    The surface and atmosphere of Titan constitute a system which is potentially as complex as that of the Earth, with the possibility of precipitation, surface erosion due to liquids, chemistry in large surface or subsurface hydrocarbon reservoirs, surface expressions of internal activity, and occasional major impacts leading to crustal melting. While none of the above have been observed as yet, the composition, density and thermal properties of Titan's atmosphere make it uniquely suited in the outer solar system as a place where such processes may occur. The one attribute of the Earth not expected on Titan is biological activity, which has had a profound effect on the evolution of the Earth's surface-atmosphere system. The earliest environment of Titan could have been warm enough for liquid ammonia-water solutions to exist on or near surface; pre-biotic organic processes may have taken place in such an environment. After a few hundred million years surface ammonia-water would have disappeared. Therefore, study of Titan through the Cassini-Huygens mission, planned for launch in 1997, primarily affords the opportunity to understand planet-wide surface-atmosphere interactions in the presence of fluids but in the absence of life. More speculative is the possibility that endogenic and exogenic heating continue to provide short-lived environments on Titan wherein pre-biotic organic processes in the presence of water happen. PMID:11539243

    Lunine, J I; McKay, C P

    1995-03-01

    223

    Near-Surface Geophysics: Advancing Earth Science Through Advances in Imaging  

    NASA Astrophysics Data System (ADS)

    The near-surface of Earth (the top ~100 m) is the region that supports human infrastructure, provides water and mineral resources, and is the interface between solid Earth and atmosphere for many of the biogeochemical cycles that sustain life. Developing an understanding of the processes and properties that occur here is essential for advancing our understanding of many parts of the Earth system. Yet our ability to study, sample, or probe this zone is remarkably primitive. Many investigations rely on drilling, trenching, and direct sampling. But given the pervasive spatial heterogeneity of the region, such methods yield information that is inadequate in terms of the spatial extent and density of sampling. As a result, the Earth science community is turning to geophysical imaging. The area of research that is focused on developing and applying geophysical methods to study this region of Earth is referred to as near-surface geophysics. Near-surface geophysics, as an area of research, includes many types of research, and many types of researchers. Some researchers are drawn to near-surface geophysics due to an interest in specific properties, processes, or applications, which can range from applied to basic science. As examples, near-surface geophysical methods are used for resource exploration and extraction, for the characterization of contaminated sites, for the assessment and design of built infrastructure; and to address scientific questions in neotectonics, volcanology, glaciology, hydrology, sedimentology, archaeology, geochemistry and biogeochemistry. Other researchers are drawn to near-surface geophysics due to an interest in the science of imaging as the driving scientific question. Advances in imaging require investigating the ways in which physical sensors can (or cannot) capture the complexity of a natural system, determining how best to quantify and enhance the spatial and temporal resolution of a measurement, developing new methods for the inversion of geophysical data to obtain an Earth image, and finding ways to transform that image to reveal new information about processes and properties. Near-surface geophysics brings together the science of imaging with the science of Earth; so challenges us to move forward in an integrated way to advance both imaging methods and Earth science.

    Knight, R.

    2006-05-01

    224

    Insulator surface breakdown in a simulated low Earth orbit environment  

    Microsoft Academic Search

    Surface flashover on insulators are investigated under UV irradiation or with a plasma background. A DC voltage up to 50 kV or a voltage pulse (up to 70 kV with 200 ns duration) is applied to the test gap, and the breakdown current, breakdown voltage, and soft X-ray emission are recorded by highly sensitive sensors with risetimes in the order

    F. Hegeler; H. Krompholz; L. L. Hatfield; M. Kristiansen

    1995-01-01

    225

    Observing Earth's Changing Environment  

    Microsoft Academic Search

    Over the last decade, a wide variety of spaceborne instruments have been developed and deployed to observe the Earth's environment on a global and almost continuous basis. Today, we have the capability to map solid surface topography, cover and subtle motion; to monitor on a global basis the ocean topography, circulation, temperature and near-surface wind; the atmospheric temperature and aerosol

    Charles Elachi

    2008-01-01

    226

    Earth materials and earth dynamics  

    SciTech Connect

    In the project ''Earth Materials and Earth Dynamics'' we linked fundamental and exploratory, experimental, theoretical, and computational research programs to shed light on the current and past states of the dynamic Earth. Our objective was to combine different geological, geochemical, geophysical, and materials science analyses with numerical techniques to illuminate active processes in the Earth. These processes include fluid-rock interactions that form and modify the lithosphere, non-linear wave attenuations in rocks that drive plate tectonics and perturb the earth's surface, dynamic recrystallization of olivine that deforms the upper mantle, development of texture in high-pressure olivine polymorphs that create anisotropic velocity regions in the convecting upper mantle and transition zone, and the intense chemical reactions between the mantle and core. We measured physical properties such as texture and nonlinear elasticity, equation of states at simultaneous pressures and temperatures, magnetic spins and bonding, chemical permeability, and thermal-chemical feedback to better characterize earth materials. We artificially generated seismic waves, numerically modeled fluid flow and transport in rock systems and modified polycrystal plasticity theory to interpret measured physical properties and integrate them into our understanding of the Earth. This is the final report of a three-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL).

    Bennett, K; Shankland, T. [and others

    2000-11-01

    227

    Low temperature laser cooling with a rare-earth doped glass  

    NASA Astrophysics Data System (ADS)

    A theoretical study of laser cooling at low temperature by anti-Stokes luminescence in a rare-earth doped glass is performed. A model is developed to evaluate the absorption and emission spectra of rare-earth ions in a glass matrix. This model allows the evaluation of the inhomogeneously broadened spectra at any temperature. It takes into account the saturation effects that occur at high excitation. The model is used to evaluate the cooling capability at low temperature of a ytterbium-doped fluorozirconate glass, the latter having been proposed in the literature as a good candidate for the cooling element of a cryocooler. Results are compared with previous estimations, confirming that one could expect a useful cooling efficiency from this material, but with smaller performances than previously estimated. Limitations to the cooling process are discussed. The reabsorption of luminescence is identified as one of the main limitations to the performance of a potential cryocooler.

    Lamouche, G.; Lavallard, P.; Suris, R.; Grousson, R.

    1998-07-01

    228

    Comparison of cropland and forest surface temperatures across the ...  

    Treesearch

    Description: Global climate models (GCM) investigating the effects of land cover on ... We found that forest surface temperatures tended to be cooler than cropland ... differences between cropland and forest average surface temperatures.

    229

    TWO SURFACE TEMPERATURE RETRIEVAL METHODS COMPARED OVER AGRICULTURAL LAND  

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Accurate, spatially distributed surface temperatures are required for modeling evapotranspiration (ET) over agricultural fields under wide ranging conditions, including stressed and unstressed vegetation. Modeling approaches that use surface temperature observations, however, have the burden of esti...

    230

    Extraterrestrial spectral solar irradiance data for modeling spectral solar irradiance at the earth's surface  

    SciTech Connect

    This report describes the extraterrestrial (air mass zero, AMO) spectral solar irradiance data used by the Solar Energy Research Institute's Resource Assessment Branch in models to calculate spectral solar irradiance at the earth's surface. The report contains tables and graphs of the AMO spectrum updated by the World Radiation Center in Daveos, Switzerland, in 1985.

    Riordan, C.

    1987-05-01

    231

    CLIMATE AND THE OCEAN CIRCULATION' 1. THE ATMOSPHERIC CIRCULATION AND THE HYDROLOGY OF THE EARTH'S SURFACE  

    Microsoft Academic Search

    The effect of the hydrology of the earth's surface is incorporated into a numerical model of the general circula- tion of the atmosphere developed at the Geophysical Fluid Dynamics Laboratory of the Environmental Science Services Administration (ESSA). The primitive equation of motion is used for this study. The nine levels of the model are distributed so as to resolve the

    SYUKURO MANABE

    232

    Circular structures of large scale and great age on the earth's surface  

    Microsoft Academic Search

    It is pointed out that the earth's surface exhibits faint circular patterns which have not been described before. These circles are characterized by near perfection of outline, by the presence of topographic highs (rims) along parts of their circumferences, and by their generally large scale (diameters from 7 to 700 km). Circles of this nature have been observed clearly in

    J. M. Saul

    1978-01-01

    233

    Implications of recent total atmospheric ozone measurements for biologically active ultraviolet radiation reaching the earth's surface  

    Microsoft Academic Search

    Recent satellite measurements of total atmospheric ozone were analyzed to deduce the changes in biologically active ultraviolet (UV) radiation reaching the Earth's surface from 1979 to 1989. The calculated increases are on average substantially larger than earlier estimates, particularly at mid and high latitudes of both hemispheres. Over the last twenty years, there has been some concern that biologically active

    Sasha Madronich

    1992-01-01

    234

    The MESSENGER Earth Flyby: First Results from the Mercury Atmospheric and Surface Composition Spectrometer  

    Microsoft Academic Search

    The MESSENGER (MErcury Surface, Space Environment, Geochemistry, and Ranging) spacecraft, NASA's first mission to orbit the planet Mercury, was launched on August 3, 2004, from Cape Canaveral Air Force Station. A gravity-assist maneuver brought the spacecraft through the Earth-Moon system with a closest approach on August 2, 2005. This event provided an important opportunity to observe the Moon with several

    G. Holsclaw; T. Bradley; W. E. McClintock; N. Izenberg; R. Vaughan; M. S. Robinson

    2005-01-01

    235

    Radiogenic isotopes: systematics and applications to earth surface processes and chemical stratigraphy  

    Microsoft Academic Search

    Radiogenic isotopes have wide application to chemical stratigraphy, geochronology, provenance studies, and studies of temporal changes in Earth surface processes. This paper briefly reviews the principles of radiogenic isotope geochemistry and the distribution of a number of elements of interest in the environment, and then uses this information to explore the range of applications to chemical stratigraphy and other fundamental

    Jay L. Banner

    2004-01-01

    236

    Platonic Plate Tectonics: On the Regularity of the Distribution of 'Triple Points' on the Earth's Surface.  

    National Technical Information Service (NTIS)

    The geometry of the division of the earth's surface by the major tectonic plates is remarkably regular and symmetric, and several models based on the platonic solids have been proposed to describe this pattern. Under such a model, the triple points, those...

    A. J. Arnold A. F. Siegel

    1981-01-01

    237

    A consideration of the effects of dust aerosol and surface dust on Snowball Earth deglaciation  

    Microsoft Academic Search

    Most previous global climate model simulations could only produce the termination of Snowball Earth episodes at CO2 partial pressures of several tenths of a bar, which is roughly an order of magnitude higher than recent estimates of CO2 levels during and shortly after Snowball events. These simulations have neglected the impact of surface dust on the ice albedo and dust

    D. S. Abbot; I. Halevy; R. Pierrehumbert

    2009-01-01

    238

    Effect of MARS Surface and Phobos Propellant Production on Earth Launch Mass.  

    National Technical Information Service (NTIS)

    Fuel and oxidizer produced on the surface of Mars and on the Martian Moon Phobos can reduce the cumulative mass of fuel and oxidizer which must be launched to low Earth orbit for Mars exploration missions. A scenario in which ten conjunction class traject...

    G. R. Babb W. R. Stump

    1986-01-01

    239

    New remote sensing techniques for the detection and quantification of earth surface CO 2 degassing  

    Microsoft Academic Search

    Earth degassing specifically of carbon dioxide CO2 is of increasing interest with respect to the global carbon budget, related climate effects, earthquake and volcano eruption mechanisms, as well as plant physiological reactions in gas-rich environments. Investigations in all of these disciplines require the detection of surface CO2 degassing structures and quantification of their emissions. We introduce minimal thermal change detection

    Volker Tank; Hardy Pfanz; Hermann Kick

    2008-01-01

    240

    Speciation of adsorbed yttrium and rare earth elements on oxide surfaces  

    NASA Astrophysics Data System (ADS)

    The distribution of yttrium and the rare earth elements (YREE) between natural waters and oxide mineral surfaces depends on adsorption reactions, which in turn depend on the specific way in which YREE are coordinated to mineral surfaces. Recent X-ray studies have established that Y 3+ is adsorbed to the rutile (1 1 0) surface as a distinctive tetranuclear species. However, the hydrolysis state of the adsorbed cation is not known from experiment. Previous surface complexation models of YREE adsorption have suggested two to four cation hydrolysis states coexisting on oxide surfaces. In the present study, we investigate the applicability of the X-ray results to rare earth elements and to several oxides in addition to rutile using the extended triple-layer surface complexation model. The reaction producing a hydrolyzed tetranuclear surface species 4>SOH+M+2HO=(>SOH)2_M(OH)2++4H was found to account for a significant fraction of the adsorbed Y 3+, La 3+, Nd 3+, Gd 3+, and Yb 3+ on rutile, hematite, alumina and silica over wide ranges of pH and ionic strength. Where adsorption data were available as a function of surface coverage for hematite and silica, an additional reaction involving a mononuclear species could be used to account for the higher surface coverages. However, it is also possible that some of the higher surface coverage data refer to surface precipitation rather than adsorption. The results of the present study provide an internally consistent basis for describing YREE adsorption which could be used to investigate more complex systems in which YREE compete both in aqueous solution and on mineral surfaces with alkaline earths and ligands such as carbonate, sulfate, chloride and organic species, in order to build a predictive adsorption model applicable to natural waters.

    Piasecki, Wojciech; Sverjensky, Dimitri A.

    2008-08-01

    241

    High temperature rare earth compounds: Synthesis, characterization and applications in device fabrication  

    NASA Astrophysics Data System (ADS)

    As the area of nanotechnology continues to grow, the development of new nanomaterials with interesting physical and electronic properties and improved characterization techniques are several areas of research that will be remain vital for continued improvement of devices and the understanding in nanoscale phenomenon. In this dissertation, the chemical vapor deposition synthesis of rare earth (RE) compounds is described in detail. In general, the procedure involves the vaporization of a REClx (RE = Y, La, Ce, Pr, Nd, Sm, Gd, Tb, Dy, Ho) in the presence of hydride phase precursors such as decaborane and ammonia at high temperatures and low pressures. Unlike traditional single source precursor techniques such as metal-organic chemical vapor deposition, the materials produced are of extremely high chemical purity. The crystallographic orientation of as-synthesized rare earth hexaboride nanostructures and gadolinium nitride thin films was controlled by judicious choice of specific growth substrates and modeled by analyzing x-ray diffraction powder patterns and crystallographic models. The vapor-liquid-solid mechanism was used in combination with the chemical vapor deposition process to synthesize single crystalline rare earth hexaboride nanostructures. Unlike previously reported synthetic techniques to generate rare earth hexaborides, my synthesis provided control over the tip diameter of the nanomaterials, was applicable to all available rare earth metals and utilized a chemical scheme that was much less toxic. Furthermore, the synthesis provided the first ever doped rare earth hexaboride nanowires. The as produced materials showed excellent electronic properties and could be applicable to many different types of electronic applications. The rare earth hexaboride nanostructures were then implemented into two existing technologies to enhance their characterization capabilities. First, the rare earth hexaboride nanowires were used as a test material for the development of a TEM based local electrode atom probe tomography (LEAP) technique. The TEM based LEAP technique is the first to combine atomic resolution crystallographic imaging with angstrom scale 3D compositional mapping. This technique also provided some of the first quantitative compositional information of the rare earth hexaboride systems and is applicable to a wide range of nanowire materials. Second, due to the rigidity and excellent conductivity of the rare earth hexaborides, nanostructures were grown onto tungsten wires for the development of robust, oxidation resistant nanomanipulator electronic probes for semiconductor device failure analysis.

    Brewer, Joseph Reese

    242

    The de Haas-van Alphen effect and the Fermi surfaces of rare earth metals  

    Microsoft Academic Search

    The de Haas-van Alphen effect is described. Experimental results for Y, Pr and Gd are interpreted in terms of Fermi surface models which all relate to a basic rare earth band structure. The q-vector for spiral magnetic structures in Y(Gd) alloys is found to be consistent with the experimental Fermi surface for Y. 1. Introduction. - Almost all useful information

    R. C. Young

    1979-01-01

    243

    Earth surface reflectivity climatology at 340–380 nm from TOMS data  

    Microsoft Academic Search

    The 340-380 nm (UV) Lambertian equivalent reflectivities (LER) of the Earth's surface, between the latitudes +70 ø , are constructed from 14.5 years of radiances measured by Nimbus-7\\/total ozone mapping spectrometer (November 1978 to May 1993). The surface LER values are obtained from the minimum reflectivity values for each 1 ø x 1.25 ø (latitude x longitude) pixel with statistically

    J. R. Herman; E. A. Celarier

    1997-01-01

    244

    From Dimming to Brightening: Decadal Changes in Solar Radiation at Earth's Surface  

    SciTech Connect

    Variations in solar radiation incident at Earth's surface profoundly affect the human and terrestrial environment. A decline in solar radiation at land surfaces has become apparent in many observational records up to 1990, a phenomenon known as global dimming. Newly available surface observations from 1990 to the present, primarily from the Northern Hemisphere, show that the dimming did not persist into the 1990s. Instead, a widespread brightening has been observed since the late 1980s. This reversal is reconcilable with changes in cloudiness and atmospheric transmission and may substantially affect surface climate, the hydrological cycle, glaciers, and ecosystems.

    Wild, Martin F.; Gilgen, Hans; Roesch, Andreas; Ohmura, Atsumu; Long, Charles N.; Dutton, Ellsworth G.; Forgan, B. W.; Kallis, A.; Russak, V.; Tsvetkov, Anatoly

    2005-05-06

    245

    Modeling ultraviolet radiation at the Earth`s surface. Part I: The sensitivity of ultraviolet irradiances to atmospheric changes  

    SciTech Connect

    A discrete-ordinate radiative transfer model is employed for the prediction of surface UV irradiances. A wide-ranging sensitivity study is undertaken to show how changes to the model input parameters affect UV irradiances at the surface. The effects of surface albedo, surface pressure, aerosol, cloud, and ozone on the UV irradiances are examined as well as the effects of model resolution. The ozone vertical profile and the temperature of the ozone layer are found to strongly influence UVB (280-320 nm) surface irradiances; the irradiance at 305 nm can be changed by as much as 17% for a fixed amount of total column ozone. The surface albedo is found to have a maximum influence on wavelengths near 320 nm; an uncertainty in the surface albedo of 0.2 leads to an 8% error in the UVB prediction. Clouds and tropospheric aerosol decrease the UV, their influence depending little on wavelength. Stratospheric aerosol is shown to be able to enhance the midwinter UVB surface irradiances while decreasing the UVA (320-400 nm) surface irradiances. 36 refs., 7 figs., 1 tab.

    Forster, P.M. [Univ. of Reading, Whiteknights, Reading (United Kingdom)

    1995-11-01

    246

    An automatic multi-spectral infrared sea surface temperature radiometer  

    Microsoft Academic Search

    Sea surface temperature (SST) is an important parameter in many operational and research activities, ranging from weather forecasting to climate research. A multi-spectral infrared sea surface temperature radiometer is a calibrating instrument capable of measuring in situ sea surface temperature to an accuracy of better than 0.1 K. This paper describes an instrument with special design features that double channel

    Jian Zhang; Enshi Qu; Jianzhong Cao; Zheyuan Fan; Hongtao Yang

    2011-01-01

    247

    Land Surface Modeling and Satellite Passive Microwave Imagery: a Comparison of Top Soil Moisture and Surface Temperature Estimates  

    NASA Astrophysics Data System (ADS)

    Improved accuracy in defining initial conditions for fully-coupled numerical weather prediction models (NWP) along with continuous internal bias corrections for baseline data generated by uncoupled Land Surface Models (LSMs) is expected to lead to improved short-term to long-range weather forecasting capability. Because land surface parameters are highly integrated states, errors in land surface forcing, model physics and parameterization tend to accumulate in the land surface stores of these models, such as soil moisture and surface temperature. This has a direct effect on the model's water and energy balance calculations, and will eventually result in inaccurate weather predictions. For the regional subset of Oklahoma, USA, surface soil moisture and surface temperature estimates obtained with a recently improved retrieval algorithm from the Advanced Microwave Scanner Radiometer (AMSR) aboard NASA's Earth Observing System (EOS) Aqua satellite are evaluated against model output of the Community Noah Land Surface Model and Community Land Model (CLM2) operated within the Land Information System (LIS) forced with atmospheric data of a variety of sources, i.e. the NCEP Global Data Assimilation System (GDAS), the European Centre of Medium Range Weather Forecast (ECMWF) and the North American Data Assimilation System (NLDAS). The surface temperature retrievals and LSM output are further evaluated against local measurements from the Mesonet observational grid in Oklahoma.

    Gouweleeuw, B.; Owe, M.

    2007-05-01

    248

    Toward a unified science of the Earth's surface: Opportunities for synthesis among hydrology, geomorphology, geochemistry, and ecology  

    Microsoft Academic Search

    The Earth's surface is shaped by the interaction of tectonics, water, sediment, solutes, and biota over a wide range of spatial and temporal scales and across diverse environments. Development of a predictive science of Earth surface dynamics integrates many disciplines and approaches, including hydrology, geomorphology, ocean and atmospheric science, sedimentary and structural geology, geochemistry, and ecology. This paper discusses challenges,

    Chris Paola; Efi Foufoula-Georgiou; William E. Dietrich; Miki Hondzo; David Mohrig; Gary Parker; Mary E. Power; Ignacio Rodriguez-Iturbe; Vaughan Voller; Peter Wilcock

    2006-01-01

    249

    Fourier power spectra of the geomagnetic field for circular paths on the Earth's surface.  

    USGS Publications Warehouse

    The Fourier power spectra of geomagnetic component values, synthesized from spherical harmonic models, have been computed for circular paths on the Earth's surface. They are not found to be more useful than is the spectrum of magnetic energy outside the Earth for the purpose of separating core and crustal sources of the geomagnetic field. The Fourier power spectra of N and E geomagnetic components along nearly polar great circle paths exhibit some unusual characteristics that are explained by the geometric perspective of Fourier series on spheres developed by Yee. -Authors

    Alldredge, L. R.; Benton, E. R.

    1986-01-01

    250

    Radiometric calibration of an airborne CO2 pulsed Doppler lidar with a natural earth surface.  

    PubMed

    Radiometric calibration of an airborne CO2 pulsed Doppler lidar has been accomplished with surface retroreflection signals from the White Sands National Monument, New Mexico. Two circular passes were made at altitudes of 6.3 and 9.3 km. The computed calibration factors for both altitudes are in excellent agreement with the value derived from standard ground-based measurements involving a fixed sandpaper target of known reflectance. This finding corroborates a previous study that successfully calibrated an airborne cw Doppler lidar with a variety of natural Earth surfaces. The present results indicate that relatively uniform Earth surface targets can be used for in-flight calibration of CO2 pulsed airborne and, in principal, other infrared lidars. PMID:12078677

    Cutten, Dean R; Rothermel, Jeffry; Jarzembski, Maurice A; Hardesty, R Michael; Howell, James N; Tratt, David M; Srivastava, Vandana

    2002-06-20

    251

    Mapping the Earth's thermochemical and anisotropic structure using global surface wave data  

    NASA Astrophysics Data System (ADS)

    We have inverted global fundamental mode and higher-order Love and Rayleigh wave dispersion data jointly, to find global maps of temperature, composition, and radial seismic anisotropy of the Earth's mantle as well as their uncertainties via a stochastic sampling-based approach. We apply a self-consistent thermodynamic method to systematically compute phase equilibria and physical properties (P and S wave velocity, density) that depend only on composition (in the Na2-CaO-FeO-MgO-Al2O3-SiO2 model system), pressure, and temperature. Our 3-D maps are defined horizontally by 27 different tectonic regions and vertically by a number of layers. We find thermochemical differences between oceans and continents to extend down to ˜250 km depth, with continents and cratons appearing chemically depleted (high magnesium number (Mg #) and Mg/Si ratio) and colder (>100°C) relative to oceans, while young oceanic lithosphere is hotter than its intermediate age and old counterparts. We find what appears to be strong radial S wave anisotropy in the upper mantle down to ˜200 km, while there seems to be little evidence for shear anisotropy at greater depths. At and beneath the transition zone, 3-D heterogeneity is likely uncorrelated with surface tectonics; as a result, our tectonics-based parameterization is tenuous. Despite this weakness, constraints on the gross average thermochemical and anisotropic structure to ˜1300 km depth can be inferred, which appear to indicate that the compositions of the upper (low Mg# and high Mg/Si ratio) and lower mantle (high Mg# and low Mg/Si ratio) might possibly be distinct.

    Khan, A.; Boschi, L.; Connolly, J. A. D.

    2011-01-01

    252

    High pressure and temperature equations of state: A tool for insight into deep Earth systems  

    NASA Astrophysics Data System (ADS)

    High pressure and temperature equations of state are powerful tools for probing the behavior of matter at extreme conditions. The recent deployment of third generation synchrotron light sources combined with stable, reproducible laser heating has allowed the measurement of high pressure and temperature equations of state in the diamond anvil cell. In this document I leverage this new capability to address several types of questions in the Earth sciences. Measurements of osmium metal are used to investigate different formulations of the equation of state and the measurement of very incompressible materials. Measurements of iron ringwoodite are used to examine trade-offs in seismic observables with thermal and compositional anomalies. Finally, the equation of state of cobalt oxide is used to make predictions about redox relations in the early Earth during core formation.

    Armentrout, Matthew Martin

    253

    Stable CW-operating waveguide lasers at room temperature in rare-earth-diffused lithium niobate  

    Microsoft Academic Search

    A means of reproducibly fabricating stable cw channel waveguide lasers in rare-earth-doped Ti:LiNbO3 is demonstrated, through careful choice of the light propagation direction. Z-propagating waveguides have been fabricated in Nd:Ti:LiNbO3 and room-temperature cw laser operation has been obtained by pumping in the 800 nm-band, with greatly reduced photorefractive instability. The reduced photorefractive damage susceptibility in this waveguide configuration has been

    Jaymin Amin; J. Andrew Aust; Norman A. Sanford

    1997-01-01

    254

    Finite element analysis of the magnetic field in rare-earth permanent magnet systems, with consideration of temperature dependence  

    Microsoft Academic Search

    A finite element method for the solution of the electromagnetic field taking account of the temperature properties of rare-earth magnets is presented. The nonuniform distribution of magnetization caused by the temperature-dependent properties of rare-earth permanent magnets is considered, and both reversible and irreversible changes in the magnetic strength of magnets with temperature are investigated. An analysis of the thermoelectromagnetic coupled

    S. Chen; K. J. Binns; Z. Liu; D. W. Shimmin

    1992-01-01

    255

    Effects of latent heat release at phase boundaries on flow in the Earth’s mantle, phase boundary topography and dynamic topography at the Earth’s surface  

    Microsoft Academic Search

    Mantle flow models that do not consider the effects of latent heat on phase boundaries typically predict dynamic surface topography too large to be compatible with observations. Here these effects were implemented in a mantle flow model and resulting changes in dynamic topography and topography of phase boundaries were computed. Inclusion of these effects was found to reduce the rms

    Bernhard Steinberger

    2007-01-01

    256

    Theoretical analysis of semiconductor surface passivation by adsorption of alkaline-earth metals and chalcogens  

    NASA Astrophysics Data System (ADS)

    We begin with the concept of semiconductor surface passivation by adsorption of sub-monolayer atomic coverages. We then present a theoretical analysis of structural reconstruction and passivating behaviour of semiconductor surfaces upon sub-monolayer adsorption of alkaline-earth metals (group II atoms) and chalcogens (group VI atoms). Specific results are presented from first-principles calculations for Ca adsorption on Si(0 0 1) and Si(1 1 1), and S adsorption on GaAs(0 0 1). The role of chemical species of adsorbate and surface atoms in achieving different degrees of passivation is highlighted.

    Srivastava, G. P.; AlZahrani, A. Z.; Usanmaz, D.

    2012-08-01

    257

    Relationship between Clouds and Sea Surface Temperatures in the Western Tropical Pacific.  

    NASA Astrophysics Data System (ADS)

    Analysis of four years of earth radiation budget, cloud, and sea surface temperature data confirms that cloud parameters change dramatically when and where sea surface temperatures increase above 300 K. These results are based upon monthly mean values within 2.5°×2.5° grid points over the `warm pool' region of the western tropical Pacific. The question of whether sea surface temperatures are influenced, in turn, by the radiative effects of thee clouds (Ramanathan and Collins) is less clear. Such a feedback, if it exists, is weak. The reason why clouds might have so little influence, despite large changes in their longwave and shortwave radiative effects, might be that the sea surface responds to both the longwave heating and the shortwave cooling effects of clouds, and the two effects nearly cancel. There are strong correlations between the rate of change of sea surface temperature and any of the radiation budget parameters that are highly correlated with the incident solar flux-implying that season and latitude are the critical factors determining sea surface temperatures. With the seasonal or both seasonal and latitudinal variations removed, the rate of change of sea surface temperature shows no correlation with cloud-related parameters in the western tropical Pacific.

    Arking, Albert; Ziskin, Daniel

    1994-06-01

    258

    Remote Sensing of Neutral Temperatures in Earth’s Thermosphere Using the Lyman-Birge-Hopfield Bands of N2: Comparisons with Satellite Drag Data  

    NASA Astrophysics Data System (ADS)

    Thermospheric temperatures from remote and in situ observations have provided valuable insights into the behavior of Earth’s space environment. Remote sensing techniques, however, have thus far been limited to providing exospheric temperatures from limb observations. And in situ observations, the primary source of exospheric temperature data, cannot provide the coverage desired for comparisons with global models. An alternative temperature sensing technique, which derives neutral temperatures from observations of molecular emissions, is attractive for its potential to provide global coverage of neutral temperatures. This method has previously been shown to produce temperatures consistent with atmospheric models. This presentation describes a more rigorous test of this technique - comparison with coincident satellite drag data, a proven source of thermospheric temperature information. Latitudinal profiles of the temperature are obtained by inversion of the (1-1) Lyman-Birge-Hopfield (LBH) band of N2 using high-resolution spectra obtained from the High resolution Ionospheric and Thermospheric Spectrograph (HITS) instrument aboard the Advanced Research and Global Observation Satellite (ARGOS). These remotely sensed temperatures are compared with temperatures derived from satellite drag data using the Mass Spectrometer and Incoherent Scatter (MSIS) 2000 model. Preliminary results show that the temperatures derived from the LBH spectra agree well with those derived from the satellite drag data. These results indicate that current instrumentation and fitting techniques are capable of remotely sensing thermospheric temperature.

    Krywonos, A.; Murray, D. J.; Eastes, R.; Budzien, S. A.; Marcos, F. A.

    2009-12-01

    259

    Spin liquid phases of alkaline-earth-metal atoms at finite temperature  

    NASA Astrophysics Data System (ADS)

    We study spin liquid phases of spin-5/2 alkaline-earth-metal atoms on a honeycomb lattice at finite temperatures. Our analysis is based on a Gutzwiller projection variational approach recast to a path-integral formalism. In the framework of a saddle-point approximation we determine spin liquid phases with lowest free energy and study their temperature dependence. We identify a critical temperature, where all the spin liquid phases melt and the system goes to the paramagnetic phase. We also study the stability of the saddle-point solutions and show that a time-reversal symmetry breaking state, a so-called chiral spin liquid phase, is realized even at finite temperatures. We also determine the spin structure factor, which, in principle, is an experimentally measurable quantity and is the basic tool to map the spectrum of elementary excitations of the system.

    Sinkovicz, P.; Zamora, A.; Szirmai, E.; Lewenstein, M.; Szirmai, G.

    2013-10-01

    260

    Ground vs. surface air temperature trends: Implications for borehole surface temperature reconstructions  

    NASA Astrophysics Data System (ADS)

    We have analyzed the relationship between surface air temperature (SAT), ground surface temperature (GST), and snow cover (SNC) over the terrestrial Northern Hemisphere based on general circulation model (GCM) simulations using GISS modelE forced with the observed SST and radiative forcing changes from 1951-1998. While SAT is the dominant influence on GST during the warm-season, it explains only half of the variance in GST during the cold-season, with SNC and pre-conditioning by prior warm-season SAT also exhibiting a sizeable and, in places, dominant influence. During a period of coincident surface warming and cold-season snowcover decrease in the model (1971-1998), mean GST increases are 0.2°C less than those in SAT, a consequence of greater exposure of the ground surface to winter cold air outbreaks. Interpretations of past SAT trends from borehole-based GST reconstructions may therefore be substantially biased by seasonal influences and snow cover changes.

    Mann, Michael E.; Schmidt, Gavin A.

    2003-06-01

    261

    30 CFR 7.101 - Surface temperature tests.  

    Code of Federal Regulations, 2010 CFR

    ...2010-07-01 false Surface temperature tests. 7.101 ...Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION...of Underground Coal Mines Where Permissible Electric... § 7.101 Surface temperature tests. The test...hour. (vi) The ambient temperature shall be...

    2010-07-01

    262

    30 CFR 7.101 - Surface temperature tests.  

    Code of Federal Regulations, 2010 CFR

    ...2009-07-01 false Surface temperature tests. 7.101 ...Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION...of Underground Coal Mines Where Permissible Electric... § 7.101 Surface temperature tests. The test...hour. (vi) The ambient temperature shall be...

    2009-07-01

    263

    30 CFR 7.101 - Surface temperature tests.  

    Code of Federal Regulations, 2013 CFR

    ...2013-07-01 false Surface temperature tests. 7.101 ...Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION...of Underground Coal Mines Where Permissible Electric... § 7.101 Surface temperature tests. The test...hour. (vi) The ambient temperature shall be...

    2013-07-01

    264

    Researchers lack data on trends in UV radiation at Earth's surface  

    Microsoft Academic Search

    Current anxiety about depletion of stratospheric ozone stems from the expected resulting increase in biologically damaging ultraviolet (UV) radiation at Earth's surface. Atmospheric ozone absorbs sunlight with wavelengths shorter than 320 nm--the highest-energy UV-B wavelengths (280-320 nm) that can damage DNA in living systems. But surprisingly, despite firm evidence the ozone layer is being eroded by chlorine and bromine from

    Zurer

    1993-01-01

    265

    Magnetic excitations of rare earth atoms and clusters on metallic surfaces.  

    PubMed

    Magnetic anisotropy and magnetization dynamics of rare earth Gd atoms and dimers on Pt(111) and Cu(111) were investigated with inelastic tunneling spectroscopy. The spin excitation spectra reveal that giant magnetic anisotropies and lifetimes of the excited states of Gd are nearly independent of the supporting surfaces and the cluster size. In combination with theoretical calculations, we argue that the observed features are caused by strongly localized character of 4f electrons in Gd atoms and clusters. PMID:22906055

    Schuh, Tobias; Miyamachi, Toshio; Gerstl, Stefan; Geilhufe, Matthias; Hoffmann, Martin; Ostanin, Sergey; Hergert, Wolfram; Ernst, Arthur; Wulfhekel, Wulf

    2012-08-22

    266

    GPS and Google Earth based 3D assisted driving system for trucks in surface mines  

    Microsoft Academic Search

    In order to reduce the number of surface mining accidents related to low visibility conditions and blind spots of trucks and to provide 3D information for truck drivers and real time monitored truck information for the remote dispatcher, a 3D assisted driving system (3D-ADS) based on the GPS, mesh-wireless networks and the Google-Earth engine as the graphic interface and mine-mapping

    Enji SUN; Antonio NIETO; Zhongxue LI

    2010-01-01

    267

    Note on the Theory of Nocturnal Radiational Cooling of the Earth's Surface  

    Microsoft Academic Search

    The present note gives a short account of a theoretical investigation of radiational cooling of the ground during nights sufficiently uniform in air-mass properties and cloudiness. The result may be of interest in connection with ground-frost prediction and with respect to cooling of the earth's surface during a polar night.Dropping the assumption of constancy of the effective radiation R during

    P. Groen

    1947-01-01

    268

    Surface fractal dimensions and textural properties of mesoporous alkaline-earth hydroxyapatites  

    NASA Astrophysics Data System (ADS)

    This work examines the surface fractal dimensions (Df) and textural properties of three different alkaline-earth hydroxyapatites. Calcium, strontium and barium hydroxyapatite compounds were successfully synthesized via chemical precipitation method and characterized using X-ray diffraction, scanning electron microscopy, energy dispersive X-ray spectrometry, Fourier transform infrared spectroscopy, and N2-physisorption measurements. Surface fractal dimensions were determined using single N2-adsorption/desorption isotherms method to quantify the irregular surface of as-prepared compounds. The obtained materials were also characterized through their surface hydroxyl group content, determined by the mass titration method. It was found that the Df values for the three materials covered the range of 0.77 ± 0.04-2.33 ± 0.11; these results indicated that the materials tend to have smooth surfaces, except the irregular surface of barium hydroxyapatite. Moreover, regarding the synthesized calcium hydroxyapatite exhibited better textural properties compared with the synthesized strontium and barium hydroxyapatites for adsorbent purposes. However, barium hydroxyapatite shows irregular surface, indicating a high population of active sites across the surface, in comparison with the others studied hydroxyapatites. Finally, the results showed a linear correlation between the surface hydroxyl group content at the external surface of materials and their surface fractal dimensions.

    Vilchis-Granados, J.; Granados-Correa, F.; Barrera-Díaz, C. E.

    2013-08-01

    269

    Characterization of Rare Earth Oxide/Gold Composites Synthesized by Control of Surface Composition  

    NASA Astrophysics Data System (ADS)

    The need for novel nanosized biosensors has resulted in increase interest in nanocomposites. The challenge in development of materials is that they should offer robust and tunable characteristics (fluorescence, magnetic, thermal behaviors, etc.) while remaining biocompatible. In this study, we use small molecules to attach transition metal nanostructures (gold spheres) to select rare earth oxide (Er^3+:Y2O3) particles synthesized by a urea precipitation method. The goal is to enhance the fluorescence of the rare earth materials through surface plasmons resonance generated by the gold structure while achieving dispersibility of the particles. The attachment of gold nanoparticles (Au NPs, ˜20 nm) to the surface of rare earth nanoparticles (RENPs, ˜100 nm) is achieved by the surface modification with (3-Mercaptopropyl) trimethoxy-silane (MPTS); the average numbers of Au NPs per RENP is controlled by the composition of MPTS and Propyltrimethoxysilane (PTMS, without functional groups). Characterization of the physical properties is performed by Fourier transform infrared spectroscopy and scanning electron microscopy. Fluorescence spectroscopy is used to compare the radiative decay rates of nanocomposites to unmodified particles. The resulting structures will be used in studies of bulk and particle polymer composites for potential biosensing and drug delivery applications.

    Yasmin, Zannatul; Dennis, Robert; Sardar, Dhiraj; Zhang, Maogen; Gorski, Waldemar; Nash, Kelly

    2010-10-01

    270

    Galactic cosmic rays and long-term trend in the U.S. surface air temperatures  

    NASA Astrophysics Data System (ADS)

    A heuristic search is conducted to see whether there is a connection between the long-term U. S. surface air temperature changes, the ionization caused by the galactic cosmic rays (GCRs) in the upper atmosphere, and the interplanetary magnetic field intensity (B) at earth orbit, in the instrumental era (1937-2010) covering seven sunspot number cycles. We find that B and GCRs may have only a subsidiary role (undefined) in contributing to the long-term changes in U.S. surface air temperature; other factors (some unknown at present) must be considered to solve the complex riddle of the climate change in terms of long-term surface air temperature changes.

    Ahluwalia, H. S.

    2012-07-01

    271

    Numerical modelling of the Earth's free surface with the level set method  

    NASA Astrophysics Data System (ADS)

    Being able to accurately model the free surface of the Earth is important for nearly all geodynamical problems. Importantly, free surface deformation is coupled to vertical motions and therefore allows for selfconsistent modelling of topography build up. Such modelling allows for additional prediction from numerical models which can be compared to real Earth observations. When using an Eulerian framework, modelling the free surface is not straightforward and the so called "sticky air" approach is often used in which the "air" is modelled as a zero density fluid which has sufficient thickness (~100km) and a low viscosity compared to the underlying crust-mantle system (~5 orders of magnitude less, e.g. Crameri et al 2012). Tracers are commonly used to account for the tracking of all materials and interfaces. We here propose to use the level set method to track the interface between the crust and the air as a simulation of the free surface. The level set method represents a n-dimensional interface by a (n+1)-dimensional function chosen to be zero at the interface and it is mathematically described as a smooth (signed-distance) function. The target interface coincides with the zero-level set and its location can be traced through time by solving the advection equation for the level set function and subsequently locating the zero-level set every time-step. The level set method has several advantages over tracers, namely 1) with the level set method the exact location of the interface is known, 2) the exact distance of every point in the domain to the interface is known and 3) it is computationally less expensive compared to using tracers (particularly in 3-D applications). We will show results of benchmarks and 3-D numerical subduction models which contain multiple level sets representing the free surface and selected internal surfaces. This research is funded by The Netherlands Research Centre for Integrated Solid Earth Science (ISES).

    Hillebrand, Bram; Thieulot, Cedric; Pranger, Casper; Geenen, Thomas; van den Berg, Arie; Spakman, Wim

    2013-04-01

    272

    Influence of Volcanic Aerosols and Oceanic Surface Temperatures on Tropospheric Temperatures.  

    National Technical Information Service (NTIS)

    For many years climatologists have been aware of the influence of the presence of volcanic dust and aerosol in the atmosphere on tropospheric temperatures. The influence of oceanic sea surface temperatures (SST) on tropospheric temperatures has also been ...

    A. R. Navato

    1979-01-01

    273

    Surface charge density on silica in alkali and alkaline earth chloride electrolyte solutions  

    Microsoft Academic Search

    The surface charge density of colloidal SiO2 (Aerosil 380) was measured in alkali chloride (0.067 and 0.20 M LiCl, NaCl, and KCl) and alkaline earth chloride (0.067 M MgCl2, CaCl2, SrCl2, BaCl2) solutions. Measurements were conducted at 25°C by potentiometric titrations using the constant ionic medium method in a CO2-free system. The experimental design measured surface charge for solutions with

    Patricia M. Dove; Colin M. Craven

    2005-01-01

    274

    Bioprotection explored: the story of a little known earth surface process  

    NASA Astrophysics Data System (ADS)

    Bioprotection is identified as an earth surface process. However, it has been little studied, little acknowledged and yet may have major implications for the operation and management of geomorphic systems. Key early observations are traced back to Darwin's ‘Voyage of the Beagle’, Geikie in the natural environment and Watson for the built environment. Recent field observations and experimental work examining bioprotection are reviewed, with a specific focus on lichens and the landscape, as are its complex interactions with other processes. A conceptual model of bioprotection is presented for the case of an epilithic lichen on a limestone surface.

    Carter, N. E. A.; Viles, H. A.

    2005-04-01

    275

    Possible connection between surface winds, solar activity and the earth's magnetic field  

    NASA Astrophysics Data System (ADS)

    Attention is given to an association between the Maunder-type solar cycles indicated by the thickness of varved sediments in Elk Lake, Minnesota, and the surface wind intensity fluctuations on a 2-year time-scale noted over a 2000-yr period during the mid-Holocene. Changes in cyclonic activity and tropospheric winds have been reported in this region several days after strong coronal mass ejections. This association implies that century-scale surface winds over the site were long-term counterparts of short term changes in aeolian activity after coronal mass ejections; the role of the weakness of the earth's magnetic field in this association is discussed.

    Anderson, Roger Y.

    1992-07-01

    276

    About the temperature distribution in the Earth on it's accumulation stage.  

    NASA Astrophysics Data System (ADS)

    Up to our time there was not a satisfy explanation of dividing process for reservoirs: core and mantle during the period of 10 million years, that result had been achieved using the data of W-Hf isotopic system. Nevertheless there had been exist an estimation for the process of dividing 100 million years. In the paper (Anfilogov, Khachay, 2005) we had suggested a new model of planet of the Earth's group accumulation. Taking into account of energy dissipation of the short-lived radioactive isotopes, first of all 26Al ,in the matter of the germs of the growing proto planets leads to the overestimation of their initial heat state. In the bodies about 100 km, the temperature in the central areas becomes higher than the melting iron temperature, whereas near the surface forms a thin cold envelope. By bodies increasing it's thickness decreases reciprocally to the body radius. The time of that stage rising is equal to 1 million years. A new mechanism of matter differentiation is realized: the relative velocities of the bodies compact with the germ are sufficient for crashing of the upper envelope and for supporting the merging of inner melted especially iron parts. The mass of the growing planet germ is not sufficient for keeping of especially silicate pieces of the envelope. Just on that stage of bodies combining, which arise (100-1000) km can be happen the effective dividing of the W-Hf system between the iron and silicate reservoirs through the period of time about or less than 10 million years. The forming of the core and mantle from that in the most divided reservoirs ends later. By mathematical modelling it is taken into account, that after the inelastic impact of the falling bodies on the germ with the fluid center area a part of pieces of the cold upper envelope because of a bit of the received kinetic energy does not as a whole leave the germ, and forms a so called "cocoon" on the orbit near the parent body. The increase of the density of particles in the "cocoon" leads to some increase of the probability of the impact with the germ that is the increase of the surface density of the matter near the germ, and the velocity of the proto planet growing depends linear from that value and therefore it also grows. Secondly, the account of the obtained dependence of the temperature distribution in the growing small bodies of the proto planet cloud from their masses allowed us quantitatively estimate the valuable contribution of that factor in the heating of the forming planet, which had not been early taken into account. That additional heat on the early stage can be urgently needed for explanation of the thermal evolution of the formed planet. That results had been achieved by support of the grant RFBR 07-05-00395.

    Khachay, Yu. V.; Anfilogov, V. N.

    2009-04-01

    277

    Rare earth elements in hydrothermal systems: Estimates of standard partial molal thermodynamic properties of aqueous complexes of the rare earth elements at high pressures and temperatures  

    Microsoft Academic Search

    Standard partial molal thermodynamic properties including association constants for 246 inorganic aqueous rare earth element (REE) complexes with chloride, fluoride, hydroxide, carbonate, sulfate, bicarbonate, nitrate, and orthophosphate can be calculated at pressures from 1 to 5000 bars and temperatures from 0 to 1000°C, using experimental data from the literature and correlation algorithms. Predicted association constants for REE complexes are used

    Johnson R. Haas; Everett L. Shock; David C. Sassani

    1995-01-01

    278

    Solar and geomagnetic activity, extremely low frequency magnetic and electric fields and human health at the Earth's surface  

    Microsoft Academic Search

    The possibility that conditions on the Sun and in the Earth's magnetosphere can affect human health at the Earth's surface has been debated for many decades. This work reviews the research undertaken in the field of heliobiology, focusing on the effect of variations of geomagnetic activity on human cardiovascular health. Data from previous research are analysed for their statistical significance,

    S. J. Palmer; M. J. Rycroft; M. Cermack

    2006-01-01

    279

    Detectability of Surface and Atmospheric Signatures in the Disk-averaged Spectra of the Earth  

    NASA Astrophysics Data System (ADS)

    We have developed a spatially and spectrally-resolved computer model of the Earth to explore the observational sensitivity to atmospheric and surface properties, and biosignatures, in disk-averaged spectra.This comprehensive model can also be used to analyze and interpret Earthshine data.Atmospheric, cloud and surface properties from existing observations and modeling studies are input to the model, which uses the Spectral Mapping Atmospheric Radiative Transfer (SMART) model to generate UV to far-IR spatially resolved high-resolution synthetic spectra. Disk-averaged synthetic spectra generated by the model were validated in the visible/Near-IR spectral range against disk- averaged Earth observations taken by the Mars Global Surveyor Thermal Emission Spectrometer (MGS- TES),the ESA Mars Express Omega instrument, and ground-based observations of earthshine reflected from the unilluminated portion of the Moon. Several atmospheric species can be identified in disk-averaged Earth spectra, and potentially detected depending on the wavelength range and resolving power of the instrument. At optical wavelengths (0.4 to 0.9 microns) O3, H2O, O2 and oxygen dimer (O2)2 are clearly apparent. CH4, N2O, CO2, O3 and H2O produce features in the near-IR (1 to 5 microns). The modeled spectra are also strongly phase-dependent, and a comprehensive 3-D model is needed to accurately model the observations. To explore the detectability of planetary characteristics, we simulated cases not available from the observational data sets, including an experiment to determine the detectability of the vegetation red edge as a function of planetary cloud cover. Our modeling shows that while land surface cover of vegetation on Earth produces a strong disk-averaged signal for a cloudless planet, even when the signal is averaged over the daily time scale, the detectability is significantly reduced in the presence of clouds, but is also a function of the observed planetary phase.

    Tinetti, G.; Meadows, V. S.; Crisp, D.; Kiang, N.; Fishbein, E.; Kahn, B.; Turnbull, M.

    2006-05-01

    280

    Possible Rainfall Reduction Through Reduced Surface Temperatures Due to Overgrazing.  

    National Technical Information Service (NTIS)

    Surface temperature reduction in terrain denuded of vegetation (as by overgrazing) is postulated to decrease air convection, reducing cloudiness and rainfall probability during weak meteorological disturbances. By reducing land-sea daytime temperature dif...

    J. Otterman

    1975-01-01

    281

    Examine infrared images that show variation in surface temperature  

    NSDL National Science Digital Library

    Find a somewhat blurry Flash animation exhibiting five years worth of surface average temperatures. Note seasonal land/water temperature contrasts. The animation can be paused and rewound to emphasize important points.

    Observatory, Nasa E.; Earth, Exploring

    282

    Evidence of Lunar Phase Influence on Global Surface Air Temperatures.  

    National Technical Information Service (NTIS)

    Intraseasonal oscillations appearing in a newly available 20-year record of satellite-derived surface air temperature are composited with respect to the lunar phase. Polar regions exhibit strong lunar phase modulation with higher temperatures occurs near ...

    E. Anyamba J. Susskind

    2000-01-01

    283

    Enhanced negative ion yields on diamond surfaces at elevated temperatures  

    Microsoft Academic Search

    Boron-doped polycrystalline diamond (BDD) and highly oriented pyrolytic graphite (HOPG) surfaces were exposed to low pressure hydrogen plasma. The relative yields of surface-produced H- ions were measured by an energy analyser quadrupole mass spectrometer. The highest H- yield was obtained at 400 °C for a BDD surface and at room temperature for an HOPG surface. At low ion bombardment energy,

    P. Kumar; A. Ahmad; C. Pardanaud; M. Carrère; J. M. Layet; G. Cartry; F. Silva; A. Gicquel; RAH Engeln

    2011-01-01

    284

    Development of globally applicable algorithm to estimate land surface temperature using satellite-borne microwave radiometer data  

    Microsoft Academic Search

    In order to understand the climate system of the Earth, it is essential to globally estimate a land surface temperature (LST) by remote-sensing satellite. Some algorithms to estimate LST using infrared (IR) radiometers have already been developed. However, LST estimated by these algorithms has a large uncertainty under some weather conditions since it is difficult to discriminate an IR radiation

    T. Maeda; K. Imaoka

    2009-01-01

    285

    Modelling the effect of an assumed cosmic ray-modulated global cloud cover on the terrestrial surface temperature  

    Microsoft Academic Search

    We have used the thermodynamic model of the climate to estimate the effect of variations in the oceanic cloud cover on the surface temperature of the Earth in the North Hemisphere (NH) during the period 1984–1990. We assume that the variations in the cloud cover are proportional to the variation of the cosmic ray flux measured during the same period.

    J. Ram??rez; B. Mendoza; V. Mendoza; J. Adem

    2004-01-01

    286

    Cloudiness as a Global Climatic Feedback Mechanism: The Effects on the Radiation Balance and Surface Temperature of Variations in Cloudiness  

    Microsoft Academic Search

    The effect of variation in cloudiness on the climate is considered in terms of 1) a relation between the radiation balance of the earth-atmosphere system and variations in the amount of cloud cover or effective cloud top height, 2) the effect on the surface temperature of variations in cloudiness, and 3) the dynamic coupling or `feedback' effects relating changes in

    Stephen H. Schneider

    1972-01-01

    287

    Biological Modulation of Deep Earth Process  

    Microsoft Academic Search

    The Earth became habitable once CO2 could be subducted into the deep mantle. It is likely that the Earth's surface became clement or even frigid within a few million years after it cooled to habitable temperatures (less than 120°C). Early life obtained its energy from chemical disequilibrium produced by internal processes within the Earth and photolysis in the air and

    Norm Sleep

    2011-01-01

    288

    Getting Beneath the Surface with the OpenEarth Framework (OEF) Virtual Globe  

    NASA Astrophysics Data System (ADS)

    Virtual globes like Google Earth and NASA WorldWind show layers of data overlaid atop the Earth’s terrain. But leading Earth science research efforts, such as EarthScope, are focused on 3D and 4D questions about the structure and evolution of the North American continent and processes controlling earthquakes and volcanoes. These research questions are fundamentally about phenomena beneath the surface, for which the terrain overlays offered by today’s virtual globes are not sufficient. Complex 3D structures revealed by geophysical techniques such as body wave tomography, shear wave splitting, earthquake locations, and subsurface drilling, need to be presented in a 3D context while also integrated with surficial data such as terrain, remotely sensed imagery and geologic mapping. GEON is developing the OpenEarth Framework (OEF) viewer to get beneath the surface of a virtual globe. The OEF viewer is a component of the open architecture of java software libraries and tools for manipulating Earth science data and presenting it visually. The OEF’s 3D visualization abilities are based on NASA WorldWind, extended to display 3D layers below the surface as well as atop it. The OEF displays 3D volumetric data such as seismic tomography as an isosurface that skins the volume by finding 3D boundaries between high and low values. The resulting isosurface is drawn beneath WorldWind’s terrain. The OEF also supports specialized layers to display subsurface structures, from earthquake hypocenters to the structure of the Moho. Multiple overlapping data sets can be combined into the same 3D visualization to build a composite view or to compare alternative versions of the same data. Visual comparison of the data below the surface with terrain, imagery and map data makes it possible to correlate subsurface structures with surface features. The OEF user interface allows isosurface boundary values and color ramps to be adjusted interactively. Multiple isosurfaces can be shown that correspond to the same or alternative data. Cutting planes can be positioned to slice through the data in different directions and display internal structure. Virtual sun-based shading of the terrain and isosurfaces gives a better sense of depth. By extending the WorldWind engine, we also take advantage of virtual globe interactivity and access to multiple WorldWind layers such as topography, satellite imagery, street maps, fault lines, and other geologic data. Beyond the visual support provided by WorldWind, OEF adds multiple software libraries for 2D and 3D data management and processing. Those libraries provide access to common Earth science file formats, including ESRI Shapefiles, ESRI Arc/Info Grids, GeoSoft GXF files, and UCAR NetCDF files. Several standard projection file formats are also supported along with reprojection into common coordinate spaces. The OEF architecture assembles these pieces into a cohesive package with 3D visualizations showing data above, atop, and beneath the terrain of a virtual globe.

    Nadeau, D. R.; Moreland, J. L.; Baru, C.; Crosby, C. J.

    2009-12-01

    289

    Temperature fields generated by the elastodynamic propagation of shear cracks in the Earth  

    Microsoft Academic Search

    Thermal perturbations associated with seismic slip on faults may significantly affect the dynamic friction and the mechanical energy release during earthquakes. This paper investigates details of the coseismic temperature increases associated with the elastodynamic propagation of shear cracks and effects of fault heating on the dynamic fault strength. Self-similar solutions are presented for the temperature evolution on a surface of

    Yuri Fialko

    2004-01-01

    290

    Doping alkaline-earth: a strategy of stabilizing hexagonal GdF3 at room temperature.  

    PubMed

    Hexagonal GdF3 is a more efficient phosphor host compared with the traditional orthorhombic form but the hexagonal phase is thermodynamically unstable at room temperature. Herein, we present a strategy to stabilize hexagonal GdF3 by doping with alkaline-earth ions in a mild hydrothermal reaction system. The selection of the dopant, effect of the dopant amount and the mechanism of the phase transition was discussed in detail. The luminescence variation of GdF3:Eu was demonstrated to verify the phase transformation. Furthermore, the upconversion luminescence of the Sr-doped and undoped GdF3:Yb/Er was investigated. PMID:24026018

    Zhao, Qi; Shao, Baiqi; Lü, Wei; Jia, Yongchao; Lv, Wenzhen; Jiao, Mengmeng; You, Hongpeng

    2013-10-15

    291

    Effects of Rare-Earth Oxides on Temperature Stability of Acceptor-Doped BaTiO3  

    NASA Astrophysics Data System (ADS)

    The effects of rare-earth oxides (Yb2O3, Ho2O3, Er2O3) on the temperature stability of acceptor doped BaTiO3 dielectrics were studied. The samples doped with 1 mol % rare-earth oxides exhibited the highest dielectric constants. Substantial reductions in grain size were observed in the specimens with 1 mol % rare-earth oxides (˜0.6 ?m) compared with the nondoped specimens (˜1.5 ?m). As the rare-earth oxide content was increased, the Curie point progressively moved to higher temperatures. The addition of rare-earth oxides improved the temperature dependence of the dielectric constants of the acceptor-doped BaTiO3-rare-earth oxide systems over the whole temperature range studied (-55 to 150°C), and the temperature coefficient of capacitance(TCC) curves satisfied the X8R requirements for >2 mol % Yb2O3 and >3 mol % Er2O3 or Ho2O3.

    Song, Young Hoon; Han, Young Ho

    2005-08-01

    292

    Enhanced negative ion yields on diamond surfaces at elevated temperatures  

    NASA Astrophysics Data System (ADS)

    Boron-doped polycrystalline diamond (BDD) and highly oriented pyrolytic graphite (HOPG) surfaces were exposed to low pressure hydrogen plasma. The relative yields of surface-produced H- ions were measured by an energy analyser quadrupole mass spectrometer. The highest H- yield was obtained at 400 °C for a BDD surface and at room temperature for an HOPG surface. At low ion bombardment energy, the maximum yield on a BDD surface is about 5 times higher than that on an HOPG surface, which has been the best carbon material so far for surface production of H- ions in caesium-free plasma. Raman measurements revealed surface modifications after plasma exposure.

    Kumar, P.; Ahmad, A.; Pardanaud, C.; Carrère, M.; Layet, J. M.; Cartry, G.; Silva, F.; Gicquel, A.; Engeln, R.

    2011-09-01

    293

    GHG Effect on Surface Temperature in Indonesia  

    NASA Astrophysics Data System (ADS)

    The increasing of green house gas emissons into the atmosphere could influence the Climate and Earth Ecosystem. The increasing CO_2 emmision in developed countries and developing countries are influenced by economic growth factor, cheaped price fuel without tax and there is not regulation yet for making arrangement energy efficiency. The result of inventarisation CO_2 emmision related to energy sector between 1990 until 2000 in Indonesia are having increased trend, and the CO_2 emmision percapita is still lower then OECD countries. The green house gas concentrations are measured continously in Bandung, Jakarta, and the others place. The CO_2 and CH_4 concentration ever had results higher than globally mean. The fluctuation of green house gas concentrations are influenced by activities of surounding research location.

    Cahyono, W. E.

    294

    Mediterranean Sea-Surface Temperature Analysis Program MEDSST.  

    National Technical Information Service (NTIS)

    The MEDSST program performs a synoptic sea-surface temperature analysis for the Mediterranean and was developed specifically for operational use by the U.S. Navy Fleet Weather Central (FWC) in Rota, Spain. The sea-surface temperature (SST) observations (s...

    S. E. Larson A. E. Anderson L. I'Anson

    1973-01-01

    295

    Modelling of sample surface temperature in an outdoor weathering test  

    Microsoft Academic Search

    A heat transfer model is constructed to derive the surface temperature of specimens in outdoor weathering. Data on thermal properties of materials and routinely collected weather data are used as inputs for the model. The model is validated against surface temperature data measured on samples of 11 different materials exposed to natural outdoor weathering in Jokioinen, Finland, over a period

    P. Bijl; A. Heikkilä; S. Syrjälä; A. Aarva; A. Poikonen

    2011-01-01

    296

    A deep stratospheric intrusion event down to the earth's surface of the megacity of Athens  

    NASA Astrophysics Data System (ADS)

    This case study investigates a stratospheric intrusion event down to the earth’s surface (near sea-level pressure) of the greater area of Athens (23.43°E 37.58°N), which occurred on 9 October 2003 and caused a remarkable increase in surface ozone concentrations not related to photochemical production. This event is among the rare case studies investigating, on the one hand, a deep stratospheric intrusion down to the earth’s surface at near sea-level pressure and, on the other, an event affecting the near surface ozone of a megacity such as Athens. The synoptic situation is described by a deep upper lever trough at 300 and 500 hPa extending over Greece, which is related to a deep tropopause fold as revealed by vertical cross sections of potential vorticity, relative humidity, divergence and vertical velocity. The analysis of potential vorticity at several isentropic levels indicates a hook-shaped streamer of high PV values (greater than 4 pvu at the 315 K isentropic level) over southeast Europe, which coincides with a streamer of dry air as observed from satellite images of water vapor. The aforementioned structure characterizes a textbook case study of stratosphere-to-troposphere transport. The Lagrangian particle dispersion model FLEXPART was used to calculate the trajectories of air particles reaching the receptor site and the fraction of particles with stratospheric origin. It reveals an important direct stratospheric impact within 1 day related to the tropopause fold described in this study with the fraction of stratospheric particles reaching maximum values of 1.9 and 4.5% for threshold values of the dynamical tropopause 2 and 1.5 pvu, respectively. Furthermore, a larger indirect aged stratospheric contribution is also revealed 4 to 5 days prior to the release, related to stratospheric intrusion events at the western Atlantic Ocean, reaching maximum values of 2.5 and 6.9% of particles crossing the 2 and 1.5 pvu potential vorticity surfaces, respectively.

    Akritidis, D.; Zanis, P.; Pytharoulis, I.; Mavrakis, A.; Karacostas, Th.

    2010-11-01

    297

    Predicting spatial and temporal patterns of soil temperature based on topography, surface cover and air temperature  

    Microsoft Academic Search

    Soil temperature is a variable that links surface structure to soil processes and yet its spatial prediction across landscapes with variable surface structure is poorly understood. In this study, a hybrid soil temperature model was developed to predict daily spatial patterns of soil temperature in a forested landscape by incorporating the effects of topography, canopy and ground litter. The model

    S. Kang; S. Kim; S. Oh; D. Lee

    2000-01-01

    298

    Determination of the surface temperature of a burning powder  

    SciTech Connect

    An improved method for determining the temperature of a powder combustion surface is proposed. The method is based on the following physical consideration: After extinguishing the powder, the heat accumulated in a relatively small surface layer propagates into the depths of the charge. If the change in temperature at some point within the charge is recorded, this will permit the establishment of a temperature profile and the determination of the combustion surface temperature of the powder at the beginning of the experiment. Thus, direct calorimetry is completely eliminated. Working formulas are obtained on the basis of a simplified plane problem of thermal conductivity for a half space simulating powder specimens after quenching.

    Chernov, Iu.V.

    1980-09-01

    299

    Room temperature polymerization of alkyl isocyanates catalyzed by rare earth Schiff base complexes  

    Microsoft Academic Search

    The polymerization of alkyl isocyanates catalyzed by rare earth chloride salen complexes\\/triisobutyl aluminum (Ln(H2salen)2Cl3·2C2H7OH\\/Al(i-Bu)3) at room temperature was investigated. The influences of ligand structure, catalyst composition, polymerization temperature,\\u000a polymerization time, the concentration of catalyst and monomer, and the polymerization solvent on the polymerization of isocyanates\\u000a were studied. It was found that under the polymerization conditions, examined La(H2salenA)2Cl3·2C2-H7OH\\/Al(i-Bu)3 (H2salenA= N,N?-disalicylideneethylene diamine)

    XiongFa Yang; XuFeng Ni; ZhiQuan Shen

    2009-01-01

    300

    Surface tension of low-temperature aqueous solutions  

    SciTech Connect

    Measurements of the surface tension have been carried out to determine the effects of both temperature and concentration on the surface tension of aqueous solutions of sodium chloride, propylene glycol, and ethylene glycol. A differential capillary-rise method was employed for the measurements. The results show that the surface tension of the ethylene glycol solution and the propylene glycol solution increases as the concentration of the solution decreases, while for the sodium chloride solution the surface tension increases monotonically as the concentration increases. The surface tension of the liquids was found to be an almost-linear function of temperature from 20{degrees}C to just above the freezing temperature. Equations for the surface tension of the three binary aqueous solutions as a function of temperature and concentration are presented.

    Horibe, A.; Fukusako, S.; Yamada, M. [Hokkaido Univ., Sapporo (Japan)

    1996-03-01

    301

    CLARA-SAL: a global 28-yr timeseries of Earth's black-sky surface albedo  

    NASA Astrophysics Data System (ADS)

    We present a novel 28-yr dataset of Earth's black-sky surface albedo, derived from AVHRR instruments. The dataset is created using algorithms to separately derive the surface albedo for different land use areas globally. Snow, sea ice, open water and vegetation are all treated independently. The product features corrections for the atmospheric effect in satellite-observed surface radiances, a BRDF correction for the anisotropic reflectance properties of natural surfaces, and a novel topography correction of geolocation and radiometric accuracy of surface reflectance observations over mountainous areas. The dataset is based on a homogenized AVHRR radiance timeseries. The product is validated against quality-controlled in situ observations of clear-sky surface albedo at various BSRN sites around the world. Snow and ice albedo retrieval validation is given particular attention using BSRN sites over Antarctica, Greenland Climate Network stations on the Greenland Ice Sheet (GrIS), as well as sea ice albedo data from the SHEBA and Tara expeditions. The product quality is found to be comparable to other previous long-term surface albedo datasets from AVHRR.

    Riihelä, A.; Manninen, T.; Laine, V.; Andersson, K.; Kaspar, F.

    2012-09-01

    302

    CLARA-SAL: a global 28 yr timeseries of Earth's black-sky surface albedo  

    NASA Astrophysics Data System (ADS)

    We present a novel 28 yr dataset of Earth's black-sky surface albedo, derived from AVHRR instruments. The dataset is created using algorithms to separately derive the surface albedo for different land use areas globally. Snow, sea ice, open water and vegetation are all treated independently. The product features corrections for the atmospheric effect in satellite-observed surface radiances, a BRDF correction for the anisotropic reflectance properties of natural surfaces, and a novel topography correction of geolocation and radiometric accuracy of surface reflectance observations over mountainous areas. The dataset is based on a homogenized AVHRR radiance timeseries. The product is validated against quality-controlled in situ observations of clear-sky surface albedo at various BSRN sites around the world. Snow and ice albedo retrieval validation is given particular attention using BSRN sites over Antarctica, Greenland Climate Network stations on the Greenland Ice Sheet (GrIS), as well as sea ice albedo data from the SHEBA and Tara expeditions. The product quality is found to be comparable to other previous long-term surface albedo datasets from AVHRR.

    Riihelä, A.; Manninen, T.; Laine, V.; Andersson, K.; Kaspar, F.

    2013-04-01

    303

    Sensible Heat Flux from the Earth's Surface under Natural Convective Conditions  

    Microsoft Academic Search

    A value for the exchange speed of sensible heat CHU under natural convective conditions was determined by both indoor and field experiments. Regardless of the type of experiment, the relationships for the CHU were obtained as CHU = b(TS T)1\\/3. For a wet surface, Tv should be substituted for (TS T). Here, TS is the ground surface temperature, T the

    Junsei Kondo; Sachinobu Ishida

    1997-01-01

    304

    Analytical asymptotic solutions to determine interactions between the planetary boundary layer and the Earth's surface  

    Microsoft Academic Search

    This study derives an asymptotic analytical solution to calculate land skin temperature, planetary boundary layer (PBL) temperature, and turbulent heat fluxes over arid and wet ground surfaces. Applying the analytical solution to field data, the turbulent heat fluxes and the daytime canopy resistance (which are difficult to measure directly) can be easily determined on the basis of solar radiation and

    Ben-Jei Tsuang

    2003-01-01

    305

    a Synoptic Characterization of the Thermal Nature of the Earth's SURFACE1  

    Microsoft Academic Search

    In view of the interrelated nature of component parts of the atmospheric circulation, it is suggested that surface- atmosphere interaction studies should be hemispheric in scope for time intervals beyond a few days. Hemispheric data sources for potentially important surface conditions-sea-surface temperature, snow cover, sea-ice extent, arid soil moisture-are discussed and an example of the extent of such data as

    R. R. Dickson

    1964-01-01

    306

    Surface tension of low-temperature aqueous solutions  

    Microsoft Academic Search

    Measurements of the surface tension have been carried out to determine the effects of both temperature and concentration on the surface tension of aqueous solutions of sodium chloride, propylene glycol, and ethylene glycol. A differential capillary-rise method was employed for the measurements. The results show that the surface tension of the ethylene glycol solution and the propylene glycol solution increases

    A. Horibe; S. Fukusako; M. Yamada

    1996-01-01

    307

    Surface Temperature and Surface-Layer Turbulence in a Convective Boundary Layer  

    NASA Astrophysics Data System (ADS)

    Previous laboratory and atmospheric experiments have shown that turbulence influences the surface temperature in a convective boundary layer. The main objective of this study is to examine land-atmosphere coupled heat transport mechanism for different stability conditions. High frequency infrared imagery and sonic anemometer measurements were obtained during the boundary layer late afternoon and sunset turbulence (BLLAST) experimental campaign. Temporal turbulence data in the surface-layer are then analyzed jointly with spatial surface-temperature imagery. The surface-temperature structures (identified using surface-temperature fluctuations) are strongly linked to atmospheric turbulence as manifested in several findings. The surface-temperature coherent structures move at an advection speed similar to the upper surface-layer or mixed-layer wind speed, with a decreasing trend with increase in stability. Also, with increasing instability the streamwise surface-temperature structure size decreases and the structures become more circular. The sequencing of surface- and air-temperature patterns is further examined through conditional averaging. Surface heating causes the initiation of warm ejection events followed by cold sweep events that result in surface cooling. The ejection events occur about 25 % of the time, but account for 60-70 % of the total sensible heat flux and cause fluctuations of up to 30 % in the ground heat flux. Cross-correlation analysis between air and surface temperature confirms the validity of a scalar footprint model.

    Garai, Anirban; Pardyjak, Eric; Steeneveld, Gert-Jan; Kleissl, Jan

    2013-03-01

    308

    AQUA AMSR-E Sea Surface Temperature  

    NASA Astrophysics Data System (ADS)

    NASA's AQUA satellite carries the JAXA's Advanced Microwave Scanning Radiometer - Earth Observing System (AMSR-E). The AQUA satellite was launched in May 2002 into a polar, sun-synchronous orbit at an altitude of 705 km, with a LECT of 1:30 AM/PM. AMSR-E has 12 channels corresponding to 6 frequencies; all except 23.8 GHz measure both vertical and horizontal polarizations. Geophysical retrievals of SST, wind speed, water vapor, cloud liquid water, and rain rates are calculated using a multi-stage linear regression algorithm derived through comprehensive radiative transfer model simulations. SST retrievals are prevented by rain, sun glint, near land emissions, and radio frequency interference due to geostationary satellite broadcasts. Since only a small number of retrievals are unsuccessful, almost complete global coverage is available daily. At high latitudes, where cloud cover regularly prevents infrared observations of SSTs, the microwave observations of SST provide a significant improvement to measurement capabilities. Validation of the datasets through comparison to the global drifting buoy networks yields mean biases of -0.02 K and standard deviations of 0.50 K. AMSR-E SSTs have been widely used for numerical weather prediction, ocean modeling, fisheries, and oceanographic research.

    Gentemann, C. L.

    2011-12-01

    309

    Observation of a monthly variation in global surface temperature data  

    Microsoft Academic Search

    An analysis of global surface temperature data is described. The data originates from the European Centre for Medium Range Weather Forecasting, and covers the period 1986-1991 with a spatial resolution of 1.125 degrees. A global average temperature, Tav, defined as the area weighted average of local temperatures, has been calculated for each day in this time period. In addition to

    Clive H. Best

    1994-01-01

    310

    Recent variability and trends of Antarctic near-surface temperature  

    Microsoft Academic Search

    A new monthly 1° × 1° Antarctic near-surface temperature reconstruction for 1960–2005 is presented. The use of numerical model fields to establish spatial relationships between fifteen continuous observational temperature records and the voids to which they are interpolated inherently accounts for the effects of the atmospheric circulation and topography on temperature variability. Employing a fixed observation network ensures that the

    Andrew J. Monaghan; David H. Bromwich; William Chapman; Josefino C. Comiso

    2008-01-01

    311

    Observation of a monthly variation in global surface temperature data  

    Microsoft Academic Search

    An analysis of global surface temperature data is described. The data originates from the European Centre for Medium Range Weather Forecasting, and covers the period 1986–1991 with a spatial resolution of 1.125 degrees. A global average temperature, Tav, defined as the area weighted average of local temperatures, has been calculated for each day in this time period. In addition to

    Clive H. Best

    1994-01-01

    312

    Observation of a monthly variation in global surface temperature data  

    Microsoft Academic Search

    An analysis of global surface temperature data is described. The data originates from the European Center for Medium Range Weather Forecasting (ECMWF), and covers the period 1986-1991 with a spatial resolution of 1.125 degrees. A global average temperature, Tav, defined as the area weighted average of local temperatures, has been calculated for each day in this time period. In addition

    Clive H. Best

    1994-01-01

    313

    Constraints on the depths and temperatures of basaltic magma generation on Earth and other terrestrial planets using new thermobarometers for mafic magmas  

    NASA Astrophysics Data System (ADS)

    Basaltic magmatism is a common feature of dynamically active terrestrial planets. The compositions of basalts reflect the temperatures and pressures of magma generation, providing windows into a planet's thermal state. Here, we present new thermobarometers based on magma Si and Mg contents to estimate the pressures and temperatures of basaltic magma generation on Earth and other terrestrial planets. Melting on Earth is intimately tied to plate tectonics and occurs mostly at plate boundaries: mid-ocean ridges and subduction zones. Beneath ridges, melting is driven by adiabatic decompression of passively upwelling mantle at 1300-1400 °C. Similar temperatures of melting are found for some arcs, suggesting that decompression melting is also important in arcs and that enhanced melting by hydrous fluxing is superimposed on this background. However, in arcs where melting temperatures are low (1200 °C), hydrous fluxing is required. Temperatures hotter than ridges (> 1400 °C) are primarily found away from plate boundaries: beneath thick continental lithosphere and oceanic "hotspots" like Hawaii. Oceanic "hotspots" are thought to derive from deep thermal upwellings ("plumes"), but some hot anomalies beneath continents are not associated with deep-seated plumes and hence must have different origins, such as thermal insulation or radioactive heating of metasomatized zones. Melting on Venus, as constrained from spectral data of its surface, occurs at higher temperatures (1500 °C) and pressures than on Earth, perhaps because Venus is characterized by a thick and stagnant upper thermal boundary layer that retards convective heat loss. In this regard, Venus' upper thermal boundary layer may be analogous to thick continents on Earth. Mars appears to have cooled off to < 1300 °C within its first billion years, but considerable controversy exists over the interpretation of young (< 500 My) basaltic meteorites that record temperatures of 1550 °C. As for the first billion years of Earth's history, its upper mantle was hotter than 1700 °C, hence melting commenced at pressures greater than 7 GPa, where melts could have been denser than residual solids, resulting in downward fertilization of the Earth's mantle.

    Lee, Cin-Ty A.; Luffi, Peter; Plank, Terry; Dalton, Heather; Leeman, William P.

    2009-03-01

    314

    Surface Temperature Responses to Natural and Anthropogenic Influences: Past, Present, and Future  

    NASA Astrophysics Data System (ADS)

    Earth's surface temperature is highly variable. Regional and seasonal changes, which can exceed the global mean variations by an order of magnitude, arise from both natural and anthropogenic influences, On time scales of years to a decade, naturally induced surface temperature changes related to the El Niño Southern Oscillation (ENSO), volcanic aerosols and solar activity can dominate current anthropogenic warming of 0.2^oC per decade, especially in some locations. Knowledge of surface temperatures in the immediate future aids in energy usage, land management and crop productivity, tourism and public health. A multivariate analysis that decomposes the observed surface temperature record (globally, regionally and in different seasons) suggests that increasing concentrations of greenhouse gases caused much (˜90%) of the long-term warming in the twentieth century. But declining global temperature since 1998, the warmest year on record, has produced wide-spread speculation that anthropogenic influences were not, in fact, the cause of the twentieth century warming or, if so, that their impact has now ceased. However, the exceptional warmth in 1998 was the result of a ``super'' El Nino. Subsequent global surface temperatures have not reach this level because cooling from La Nina events combined with declining solar brightness has countered much of the anthropogenic warming of the past 6 years. Using the best available estimates of future solar and anthropogenic influences we anticipate that global surface temperatures will increase 0.15^oC, from 2009 to 2014, at a rate 50% greater than predicted by IPCC. But as a result of declining solar activity in the subsequent five years, average temperature in 2019 is only 0.03^oC warmer than in 2014. A major volcanic eruption or a super ENSO would modify these projections, in ways that can be factored into the forecasts. )

    Lean, Judith

    2010-02-01

    315

    LETTER TO THE EDITOR: On the factors affecting the high temperature insulator-metal transition in rare-earth manganites  

    Microsoft Academic Search

    The measurement of resistivity (rho) across a wide temperature (T) range - from 15 to 1473 K - in the rare-earth manganite series of compounds reveals a very interesting feature: the normally observed insulating pattern beyond Tc (the Curie point) undergoes a broader transition and eventually gives way to a reentrant metallic pattern around a characteristic temperature T*. Considering a

    Dipten Bhattacharya; Pintu Das; A. Pandey; A. K. Raychaudhuri; Amitava Chakraborty; V. N. Ojha

    2001-01-01

    316

    Estimation of Lunar Surface Temperatures: a Numerical Model  

    NASA Astrophysics Data System (ADS)

    About 40 years after the Apollo and other lunar missions, several nations return to the Moon. Indian, Chinese, Japanese and American missions are already in orbit or will soon be launched, and the possibility of a "Made in Germany" mission (Lunar Exploration Orbiter - LEO) looms on the horizon [1]. In preparation of this mission, which will include a thermal infrared spectrometer (SERTIS - SElenological Radiometer and Thermal infrared Imaging Spectrometer), accurate temperature maps of the lunar surface are required. Because the orbiter will be imaging the Moon's surface at different times of the lunar day, an accurate estimation of the thermal variations of the surface with time is necessary to optimize signal-to-noise ratios and define optimal measurement areas. In this study we present new global temperature estimates for sunrise, noontime and sunset. This work provides new and updated research on the temperature variations of the lunar surface, by taking into account the surface and subsurface bulk thermophysical properties, namely their bulk density, heat capacity, thermal conductivity, emissivity and albedo. These properties have been derived from previous spacecraft-based observations, in-situ measurements and returned samples [e.g. 2-4]. In order to determine surface and subsurface temperatures, the one-dimensional heat conduction equation is solved for a resolution of about 0.4°, which is better by a factor of 2 compared to the Clementine measurement and temperature modeling described in [2]. Our work expands on the work of Lawson et al. [2], who calculated global brightness temperatures of subsolar points from the instantaneous energy balance equation assuming the Moon to be a spherical object [2]. Surface daytime temperatures are mainly controlled by their surface albedo and angle of incidence. On the other hand nighttime temperatures are affected by the thermal inertia of the observed surface. Topographic effects are expected to cause earlier or later sunrises and therefore high-standing areas receive sunlight for longer time, while sloping surfaces lead to a time displacement of the temperature cycle. For our model, some simplifications were necessary. In order to determine the solar influx, the Moon is assumed to be spherical. As there are only few landing sites from which soil properties were determined, the subsurface conditions are considered as homogeneous over the whole Moon. Our study shows that the maximum surface temperatures for latitudes between 75°N and 75° vary between 240K at high latitudes and 390K at the mare regions near the equator. Temperatures for latitudes higher than 75° have been excluded because topographic effects intensely influence the temperatures. Nighttime temperatures are around 100K, which is in good agreement with the Apollo 15 and 17 temperature measurements described by Keihm and Langseth [5]. In order to determine the albedo influence on surface temperatures a map that shows the difference between albedo influenced temperatures minus temperatures of a uniform surface has been created. Maximum temperatures differ about ±15K between mare regions and highlands. Topographic effects due to sloping surfaces have also been investigated. For example surfaces having a slope of 20° reach their maximum temperatures about 2 days before or after a plane surface, depending on their orientation. Temperature differences of 150K have been found between sloping (20°) and non-sloping surfaces shortly after sunrise. [1] Jaumann, R. et al. (2008) LPSC XXXIX, Abstract #1253; [2] Lawson, S. L. et al. (2000) JGR 105, E2, 4273-4290; [3] Langseth, M. G. et al. (1972) The Moon, Vol. 4, 390-410; [4] Racca, G. D. (1995) Planet. Space Sci., Vol 43, No. 6, 835-842; [5] Keihm, S. J. and Langseth, M. G. (1973) Proc. Lunar Sci. Conf. 4th, 2503-2513

    Bauch, K.; Hiesinger, H.; Helbert, J.

    2009-04-01

    317

    Inversion of seismic and geodetic data for the major element chemistry and temperature of the Earth's mantle  

    Microsoft Academic Search

    We jointly invert global seismic traveltime data, mean mass, and mean moment of inertia for Earth's mantle composition and thermal state using a stochastic sampling algorithm. The chemical composition of the silicate Earth is modeled within the system CaO-FeO-MgO-Al2O3-SiO2. Given these parameters we calculate the stable mineralogy and its elastic properties and density as a function of pressure and temperature

    A. Khan; J. A. D. Connolly; S. R. Taylor

    2008-01-01

    318

    Changes in biologically-active ultraviolet radiation reaching the Earth's surface.  

    PubMed

    The Montreal Protocol is working. Concentrations of major ozone-depleting substances in the atmosphere are now decreasing, and the decline in total column amounts seen in the 1980s and 1990s at mid-latitudes has not continued. In polar regions, there is much greater natural variability. Each spring, large ozone holes continue to occur in Antarctica and less severe regions of depleted ozone continue to occur in the Arctic. There is evidence that some of these changes are driven by changes in atmospheric circulation rather than being solely attributable to reductions in ozone-depleting substances, which may indicate a linkage to climate change. Global ozone is still lower than in the 1970s and a return to that state is not expected for several decades. As changes in ozone impinge directly on UV radiation, elevated UV radiation due to reduced ozone is expected to continue over that period. Long-term changes in UV-B due to ozone depletion are difficult to verify through direct measurement, but there is strong evidence that UV-B irradiance increased over the period of ozone depletion. At unpolluted sites in the southern hemisphere, there is some evidence that UV-B irradiance has diminished since the late 1990s. The availability and temporal extent of UV data have improved, and we are now able to evaluate the changes in recent times compared with those estimated since the late 1920s, when ozone measurements first became available. The increases in UV-B irradiance over the latter part of the 20th century have been larger than the natural variability. There is increased evidence that aerosols have a larger effect on surface UV-B radiation than previously thought. At some sites in the Northern Hemisphere, UV-B irradiance may continue to increase because of continuing reductions in aerosol extinctions since the 1990s. Interactions between ozone depletion and climate change are complex and can be mediated through changes in chemistry, radiation, and atmospheric circulation patterns. The changes can be in both directions: ozone changes can affect climate, and climate change can affect ozone. The observational evidence suggests that stratospheric ozone (and therefore UV-B) has responded relatively quickly to changes in ozone-depleting substances, implying that climate interactions have not delayed this process. Model calculations predict that at mid-latitudes a return of ozone to pre-1980 levels is expected by the mid 21st century. However, it may take a decade or two longer in polar regions. Climate change can also affect UV radiation through changes in cloudiness and albedo, without involving ozone and since temperature changes over the 21st century are likely to be about 5 times greater than in the past century. This is likely to have significant effects on future cloud, aerosol and surface reflectivity. Consequently, unless strong mitigation measures are undertaken with respect to climate change, profound effects on the biosphere and on the solar UV radiation received at the Earth's surface can be anticipated. The future remains uncertain. Ozone is expected to increase slowly over the decades ahead, but it is not known whether ozone will return to higher levels, or lower levels, than those present prior to the onset of ozone depletion in the 1970s. There is even greater uncertainty about future UV radiation, since it will be additionally influenced by changes in aerosols and clouds. PMID:17344959

    McKenzie, R L; Aucamp, P J; Bais, A F; Björn, L O; Ilyas, M

    2007-02-15

    319

    Temperature dependent droplet impact dynamics on flat and textured surfaces  

    NASA Astrophysics Data System (ADS)

    Droplet impact dynamics determines the performance of surfaces used in many applications such as anti-icing, condensation, boiling, and heat transfer. We study impact dynamics of water droplets on surfaces with chemistry/texture ranging from hydrophilic to superhydrophobic and across a temperature range spanning below freezing to near boiling conditions. Droplet retraction shows very strong temperature dependence especially on hydrophilic surfaces; it is seen that lower substrate temperatures lead to lesser retraction. Physics-based analyses show that the increased viscosity associated with lower temperatures combined with an increased work of adhesion can explain the decreased retraction. The present findings serve as a starting point to guide further studies of dynamic fluid-surface interaction at various temperatures.

    Alizadeh, Azar; Bahadur, Vaibhav; Zhong, Sheng; Shang, Wen; Li, Ri; Ruud, James; Yamada, Masako; Ge, Liehui; Dhinojwala, Ali; Sohal, Manohar

    2012-03-01

    320

    Video microscopic high-temperature measurement of surface tension.  

    PubMed

    In this paper, a micropipette-in-microcapillary method and its experimental setup are described for the study of temperature effects on surface tension. Temperature control within the confined space of a capillary was achieved by coating the outer surface of the housing microcapillary with an electrically conductive, transparent, tin-doped indium oxide (ITO) thin film as a heating jacket. The precision of this technique was discussed according to the comparisons of our results with published reference data for water, n-hexadecane, and n-decane at room temperature. The technique was further used to measure the temperature-dependent surface tension of n-decane between 25°C and 110°C and n-hexadecane from 25°C to 200°C. The results were in excellent agreement with available published values, and also indicated linear decrease rates of surface tension with decreasing temperatures. PMID:23273546

    Duan, Yufei; Deshiikan, Srinivasa R; Papadopoulos, Kyriakos D

    2012-12-05

    321

    Transport toward earth of ions sputtered from the moon's surface by the solar wind  

    NASA Astrophysics Data System (ADS)

    The transport of typical ions from the surface of the Moon to the vicinity of Earth was calculated using a test particle approach. It was assumed that the ions were sputtered from the surface by the solar wind, with fluxes in the range determined experimentally by Elphic et al. (1991), and were accelerated initially to 10 eV by the potential of the Moon on its sunlit side. Si(+) and Ca(+) ions were selected for this transport analysis because their masses are within two prominent ion mass groups that have high sputtering yields. In the solar wind the ion trajectories were traced in the following superimposed fields: (1) a steady magnetic field B0 at an angle of 45 deg to the solar wind velocity VSW, (2) the motional electric field Ezero = -V(sub SW x B0, and (3) turbulent magnetic and electric fields generated by hydromagnetic waves with a k-space power spectrum of absolute value of k-5/3 propagating along both directions of the magnetic field B0. Interactions with Earth's bow shock and magnetosphere were included. Case histories of the ions were recorded in the XGSM, YGSM plane and in various planes perpendicular to the E0 x B0 drift direction of the ions between the Moon and Earth. The number density, energy and angular distributions, and directional and omnidirectional fluxes of the ions were constructed from the case histories. It was found that the diffusion of the ions increases rapidly as the amplitude of the turbulence delta Brms increases beyond the value 0.04 B0. Recent measurements of lunar ions upstream of the bow shock by Hilchenbach et al. (1992) generally confirm the predicted behavior of the ions.

    Cladis, J. B.; Francis, W. E.; Vondrak, R. R.

    1994-01-01

    322

    Temperature Dependent Mössbauer Spectra of Aluminous Perovskite and Implications for the Earth's Lower Mantle  

    NASA Astrophysics Data System (ADS)

    Perovskite in the Earth's lower mantle contains 4.0~5.3 weight % Al (Wood and Rubie, Science. 1996). To date Mössbauer data on Al-PV under cryogenic conditions have not been reported. In this study, we measured Mössbauer spectra of an Al-PV sample at 65 to 300 K and 1 bar. The temperature dependence of the center shift, fitted by Debye model, gives recoil-free fractions of fFe2+ and fFe3+, which are critical for calculating Fe3+/?Fe ratio. The high relative concentration of Fe3+ of our Al-PV sample is consistent with previous studies on Al-PV samples containing a similar amount of aluminum (Lauterbach et al., Contrib Mineral Petrol. 2000). However, it cannot be attributed to disproportionation of Fe2+ (Frost et al., Nature. 2004), because neither metallic iron nor wüstite was observed in the Mössbauer spectra or electron probe analysis. In comparison to other capsule materials used in previous studies, such as graphite, iron, or rhenium, the gold capsule used in our synthesis is chemically inert, and does not influence the oxidation environment. A likely candidate to oxidize Fe2+ into Fe3+ in PV structure is H2O trapped as moisture. Earth's lower mantle may contain 2.5~5 times H2O of the present ocean's mass (Murakami et al., Science. 2002; Litasov et al., Earth Planet. Sci. Lett. 2003), a high Fe3+/?Fe ratio in lower mantle Al-PV can be achieved without disproportionation of Fe2+. Recent studies (McCammon et al., Nature Geosci. 2008; Lin et al., Nature Geosci. 2008) found a high quadrupole splitting (QS) (~4 mm s-1) component in Al-free PV at pressures above 30 GPa, and assigned it to intermediate-spin ferrous iron. The high QS component in our Al-PV sample has similar hyperfine parameters. Its relative concentration changes with temperature, possibly due to a temperature-induced change in the degree of lattice distortion (Bengtson et al., Geophys. Res. Lett. 2009).

    Liu, J.; Mysen, B. O.; Fei, Y.; Mao, H.; Hemley, R. J.; Li, J.

    2011-12-01

    323

    Electronic states of monatomic layers of alkali and rare earth metals adsorbed on graphene surfaces  

    NASA Astrophysics Data System (ADS)

    The electronic states of ordered layers of alkali and rare earth metals adsorbed on graphene surfaces are examined using an Anderson model. The behavior of the density of states of these systems is analyzed. The case of an adsorbed metallic nanolayer with a discrete energy spectrum is discussed. A system whose electronic states can be controlled by an applied electric field is proposed and is of great practical interest. The qualitative difference between the existing theoretical approach to this problem and the present paper is that the former uses a "single adatom" formalism that does not deal with the band structure of the metallic adlayer. A way of describing the electronic states of an adsorbed layer of Gd and other metallic layers which form a fractal structure on a graphene surface is also examined.

    Alisultanov, Z. Z.

    2013-02-01

    324

    Ions originating from the Moon surface / exosphere observed in the Earth's magnetosphere  

    NASA Astrophysics Data System (ADS)

    MAgnetic field and Plasma experiment - Plasma energy Angle and Composition Experiment (MAP-PACE) on Kaguya (SELENE) measured lunar plasmas in a polar orbit with an altitude of 100km, 50km, and in an elliptical orbit with perilune altitude as low as 10km. When Kaguya stayed in the Earth's magnetosphere, one of the MAP-PACE sensors IMA (Ion Mass Analyzer) detected ions from the Moon surface [Tanaka et al., GRL 36, L22106, 2009]. These ions were observed when the Moon was in the magnetospheric lobe, on the dayside of the Moon, especially when the solar zenith angle was below 40 degrees. IMA detected peaks for the heavy ions including C+, O+, Na+, K+, and Ar+ that indicated that these ions were originating from the Moon surface / exosphere. When these ions were discovered, they were considered to be accelerated by the potential difference between the lunar surface and Kaguya. Both the lunar surface and Kaguya were positively charged on the dayside of the Moon since photoelectron and electron currents are the major current sources and the photoelectron current dominates the current balance. Since the Debye length was larger than the spacecraft and much smaller than the Moon, it might be possible for the Moon surface to be positively charged to a higher potential than Kaguya. However, the recent detailed study on the ion flow direction with respect to the magnetic field revealed that the ion flow direction was mostly perpendicular to the magnetic field. It suggests that these ions were mostly accelerated by the convection electric field in the Earth's magnetotail. This hypothesis was proved by investigating an example that lobe cold ions were detected by another MAP-PACE ion sensor IEA while ions originating from the Moon surface / exosphere were detected by IMA. The ions originating from the Moon surface / exosphere also showed characteristic variation of the flux intensity that presumably related with the lunar surface structure or composition. Understanding the lunar plasmas will contribute to our understanding of the interaction between solar wind / magnetosphere and numerous non-magnetized airless bodies.

    Saito, Y.; Yokota, S.; Nishino, M. N.; Yamamoto, T.; Uemura, K.; Tsunakawa, H.

    2012-04-01

    325

    Elasticity of iron at the temperature of the Earth's inner core.  

    PubMed

    Seismological body-wave and free-oscillation studies of the Earth's solid inner core have revealed that compressional waves traverse the inner core faster along near-polar paths than in the equatorial plane. Studies have also documented local deviations from this first-order pattern of anisotropy on length scales ranging from 1 to 1,000 km (refs 3, 4). These observations, together with reports of the differential rotation of the inner core, have generated considerable interest in the physical state and dynamics of the inner core, and in the structure and elasticity of its main constituent, iron, at appropriate conditions of pressure and temperature. Here we report first-principles calculations of the structure and elasticity of dense hexagonal close-packed (h.c.p.) iron at high temperatures. We find that the axial ratio c/a of h.c.p. iron increases substantially with increasing temperature, reaching a value of nearly 1.7 at a temperature of 5,700 K, where aggregate bulk and shear moduli match those of the inner core. As a consequence of the increasing c/a ratio, we have found that the single-crystal longitudinal anisotropy of h.c.p. iron at high temperature has the opposite sense from that at low temperature. By combining our results with a simple model of polycrystalline texture in the inner core, in which basal planes are partially aligned with the rotation axis, we can account for seismological observations of inner-core anisotropy. PMID:11544523

    Steinle-Neumann, G; Stixrude, L; Cohen, R E; Gülseren, O

    2001-09-01

    326

    Modeling novel isotopic proxies of the oxygenation of the earth's surface  

    NASA Astrophysics Data System (ADS)

    Tracking the evolution of the oxidation state of the Earth's surface environment has increased understanding of the biological, atmospheric, oceanic, and geological evolution of the Earth, and may allow us to broaden the search for life on extrasolar planets. In this thesis, two relatively new proxies for the evolution of the Earth's surface oxidation state are examined. Both proxies use stable isotope measurements to identify a permanent oxidation of the surface that occurred between ˜2.4 and ˜1.8 billion years ago (Ga). Measurements of the stable isotopes of Fe (54Fe, 56Fe, and 57Fe) in sediments demonstrate an increase in maximum 56Fe/54Fe prior to ˜1.8 billion years ago (Ga) and an increase in the maximum and decrease in the minimum 56Fe/54Fe prior to ˜2.3 Ga. These data have been interpreted as being the result of stepwise changes to the oxidation state of the Earth's oceans. However, the measurement of Fe isotopes has also been proposed as a way to identify a history of life in a sample, as Fe isotopes have been shown to fractionate during metabolic processes and upon complexation with organic acids. In the first two chapters of the thesis, the fractionation associated with complexation of Fe with organic ligands is modeled. Equilibrium constants are predicted for equilibrium isotope exchange for redox and ligand exchange reactions. These predictions allow comparison of these two types of fractionation and place the two proposed uses of Fe isotopes in better theoretical context. Another novel tool for tracking the redox history of the Earth is the measurement of multiple S isotopes. In sediments younger than ˜2.3 Ga, the fractionation of the stable S isotopes (32S, 33 S, 34S, and 36S) follows specific trends that depend on the mass of the isotopes. This behavior is classified as mass-dependent fractionation, and is witnessed for almost all known kinetic, equilibrium, and biological fractionation processes. However, sediments older than ˜2.45 Ga do not follow this trend. As such they are said to exhibit mass-independent fractionation of Sulfur isotopes (S-MIF), a process that has been recreated in the laboratory using photolysis of SO2 using UV light. The presence of S-MIF in these older rocks is commonly accepted as evidence that atmospheric O2 concentrations permanently rose at ˜2.4 Ga, establishing an ozone shield that shielded SO2 from UV radiation and prevented the creation of S-MIF in the lower atmosphere. Subsequent analyses have uncovered secondary features in the S-MIF record. The most notable excursion is a decline in the magnitude of S-MIF between ˜3.2 and ˜2.7 Ga that has been used to invalidate the aforementioned use of S-MIF to date the rise of atmospheric O2. Chapter 3 proposes a new control on S-MIF---namely an organic haze that could have shielded SO2 from UV radiation and prevented S-MIF in an anoxic atmosphere. This is modeled with a 1-dimensional photochemical code that predicts reaction rates for photolysis of SO2. Chapter 4 examines the climatic implications of the haze and of other hydrocarbon species that would have been present in the Archean atmosphere, given the constraints placed by isotopic and other geochemical indicators. Finally, Chapter 5 summarizes this work by explaining Archean trends in C, S, and Fe isotopes with a sequence of changes to the Earth's biosphere, atmosphere, and climate.

    Domagal-Goldman, Shawn D.

    327

    Temperature range and conditions of stable operation of gas-discharge rare-earth metal vapor lasers  

    Microsoft Academic Search

    We have experimentally studied the temperature range and conditions of the stable operation of rare-earth metal (REM) vapor\\u000a lasers. Gas-discharge tubes made of alumina (Al2O3-GDTs) were used in the experiments. The lasing appears at the temperature when the saturated-vapor pressure of REMs reaches\\u000a the value of 0.1 Torr and abruptly drops at the melting temperature of corresponding REM under any excitation

    V. A. Gerasimov; V. V. Gerasimov; A. V. Pavlinskiy

    2008-01-01

    328

    An intercomparison study on models of sensible heat flux over partial canopy surfaces with remotely sensed surface temperature  

    Microsoft Academic Search

    Using remotely sensed surface temperature to estimate the sensible heat flux over partial canopy covered surfaces, one faces the problem of how the bare soil and plant foliage temperatures contributing to the radiometric surface temperature are related to the turbulent transport of sensible heat across the surface-atmosphere interface. To solve this problem, several sensible heat models, using radiometric surface temperature,

    X. Zhan; W. P. Kustas; K. S. Humes

    1996-01-01

    329

    Nontraditional 'Deliverers' of UHP Rocks from Earth's Deep Interior to the Surface  

    NASA Astrophysics Data System (ADS)

    It is widely accepted that fragments of deeply subducted continental and/or oceanic crust may return from depths ~200-300 km to the surface as UHPM rocks forming collisional orogenic belts. These rocks, containing UHP minerals or microstructural relics of their decompressions, as well as mantle xenoliths and diamonds from kimberlitic pipes, are valuable fragments that provide snapshots of mantle mineralogy, melt, and fluids at depths of >100 to 1,700 km. Within them, diamond is the best indicator of the greater depth (up to 1,700 km) because it serves as an almost ideal natural 'container' which is capable to preserve unchanged inclusions of UHP phases. Recently, diamond was reported from an oceanic island, a mid-oceanic ridge ophiolite, and a forearc geodynamic structure, which are not suitable places for diamond formation and its transportation to the Earth's surface. This is because magmas associated with the mentioned geodynamic environments are thought to originate at shallow depth where pressure is too low and oxygen fugacity too high for diamond stabilisation. The first finding of nm-sized diamond in melt inclusions in mantle-derived garnet pyroxenite xenolith from Salt Lake Crater (Hawaii) was only possible using foils for cut TEM investigations by Focused Ion Beam (Wirth and Rocholl, 2003). Diamonds associated with native Fe and Cu, FeS, FeS2, ZnS, AgS, and several Ti-, Nb-, Zr-, Ir-, In-, and Pd-rich phases occur within Si-rich glass, forming small domains filled with dozens of ~20-nm-size crystals. Another microdiamond was discovered inside an OsIr inclusion from a chromite pod included in a mantle section of the Luobasa ophiolite formation of Tibet which marks the geological boundary between Asia and India (Yang et al., 2007). Prismatic domains of polycrystalline coesite found in the same massive chromite ore suggest pseudomorphic replacement of stishovite. Other UHP phases TiN, c-BN, TiO2 II and coesite exsolution lamellae are also found in the Luobasa chromites (Dobrzhinetskaya et al., 2007; Yamamoto et al., 2007), suggesting depth of their possible origin over 400 km. Solid-state transport within massive chromitite appears the only vehicle capable of transporting these phases and preserving their low-fO2 environment at the very high temperatures of oceanic spreading centers. Similar findings have now been made in other ophiolites. Microdiamond in clinopyroxene from a Cenozoic lamprophyre dike was discovered in a forearc setting on Shikoku island, Japan (Mizukami et al., 2008). Studies provide a pressure constraint of 5.5 GPa, which suggests that the diamond-bearing rocks rose to the forearc region from depths of ~160 km. This implies that mantle flow in convergent plate boundaries occurs on a larger scale than was previously recognized. The discoveries of UHP minerals in rocks located within 'forbidden' geological settings indicate that a new understanding is needed of the interactions between mantle convection and oceanic islands, forearcs, and oceanic spreading centers, as well as the depths of their magma formation.

    Dobrzhinetskaya, L.; Wirth, R.; Yang, J.; Green, H. W.

    2008-12-01

    330

    Surface Tension Gradients Induced by Temperature: The Thermal Marangoni Effect  

    ERIC Educational Resources Information Center

    |Surface tensions gradients were generated in a thin liquid film because of the local increase in temperature, for demonstration purposes. This is performed using a simple experiment and allows different alternatives for heat generation to be used.|

    Gugliotti, Marcos; Baptisto, Mauricio S.; Politi, Mario J.

    2004-01-01

    331

    Temperature Measurement on Operating Surface Mounted Lighting Fixtures.  

    National Technical Information Service (NTIS)

    Potentially hazardous temperatures may result from adding thermal insulation in the attic above surface mounted incandescent lighting fixtures and/or operating these fixtures with lamps of higher wattage than specified. This study was concerned with the r...

    P. M. Fulcomer

    1979-01-01

    332

    Variations in FASST Predictions of Soil Surface Temperatures.  

    National Technical Information Service (NTIS)

    This report presents the results of a systematic investigation of the variation in soil surface temperatures predicted by the numerical model FASST (Fast All Seasons Soil Strength), using different values of soil physical, thermal, and optical parameters....

    L. Peck

    2006-01-01

    333

    Tensile testing method for rare earth based bulk superconductors at liquid nitrogen temperature  

    NASA Astrophysics Data System (ADS)

    Bending tests have been commonly carried out to investigate the mechanical properties of melt-processed rare earth based bulk superconductors. Tensile tests by using small specimen, however, are preferable to evaluate the detailed distribution of the mechanical properties and the intrinsic elastic modulus because no stress distributions exist in the cross-section. In this study, the tensile test method at low temperature by using specimens with the dimensions of 3 × 3 × 4 mm from Y123 and Gd123 bulks was examined. They were glued to Al alloy rods at 400 K by using epoxy resin. Tests were carried out at liquid nitrogen temperature (LNT) by using the immersion type jig. Although the bending strength in the direction perpendicular to the c-axis of the bulks at LNT is higher than that at room temperature (RT), the tensile strength at LNT was lower than that at RT. Many of specimens fractured near the interface between the specimen and the Al alloy rod at LNT. According to the finite element method analysis, it was shown that there was a peak thermal stress in the loading direction near the interface and it was significantly higher at LNT than that at RT. It was also shown that the replacement of the Al alloy rod to Ti rod of which the coefficient of thermal expansion is close to that of bulks significantly increased the tensile strength.

    Kasaba, K.; Katagiri, K.; Murakami, A.; Sato, G.; Sato, T.; Murakami, M.; Sakai, N.; Teshima, H.; Sawamura, M.

    2005-10-01

    334

    High-temperature fixed points for pre-launch calibration of earth observing sensors  

    NASA Astrophysics Data System (ADS)

    High-temperature fixed points of metal-carbon systems, currently the target of a project in the international thermometry standards community, is also of high interest for pre-launch radiometric calibration of hyperspectral earth observing sensor in the blue wavelengths, where the conventional copper fixed point fails to supply sufficient radiance. For such a calibration, a fixed-point possibly around 2000 K is desired. One requirement for application of the high-temperature blackbody fixed-point cell to remote sensor calibration is to increase the radiating source aperture diameter to a size large enough to target with a radiance comparator based on a grating monochromator. In this presentation, a fixed-point cell of Co-C eutectic (1597 K) for remote sensor calibration application is described. An enlarged 7-mm aperture design is employed for the fixed-point cell while at the same time retaining the outer dimension to fit in existing fixed-point furnaces. The observed plateaux showed temperature and repeatability comparable to conventional 3-mm aperture cells, while cavity breakages indicates the need for improved robustness in the crucible design. Extension of the technique to Pt-C eutectic (2011 K) or Cr3C2-C peritectic (2100 K) systems, and subsequent application to calibration of the HISUI sensor is envisaged.

    Yamada, Yoshiro; Ishii, Juntaro

    2011-09-01

    335

    Surface Temperatures and Temperature Gradient Features of the U.S. Gulf Coast Waters.  

    National Technical Information Service (NTIS)

    Satellite thermal infrared data on the Gulf of Mexico show that a seasonal cycle exists in the horizontal surface temperature structure. In the fall, the surface temperatures of both coastal and deep waters are nearly uniform. With the onset of winter, at...

    O. K. Huh L. J. Rouse G. W. Smith

    1977-01-01

    336

    Impact of Subsurface Temperature Variability on Surface Air Temperature Variability: An AGCM Study  

    Microsoft Academic Search

    Anomalous atmospheric conditions can lead to surface temperature anomalies, which in turn can lead to temperature anomalies in the subsurface soil. The subsurface soil temperature (and the associated ground heat content) has significant memory—the dissipation of a temperature anomaly may take weeks to months—and thus subsurface soil temperature may contribute to the low-frequency variability of energy and water variables elsewhere

    Sarith P. P. Mahanama; Randal D. Koster; Rolf H. Reichle; Max J. Suarez

    2008-01-01

    337

    Tribological performance of surface engineered tool steel at elevated temperatures  

    Microsoft Academic Search

    Tribological components operating at elevated temperatures can experience high wear, oxidation, thermal fatigue and changes in mechanical properties. In this work, the friction and wear characteristics of plasma nitrided and surface coated (CrN and TiAlN) tool steel during sliding against AISI52100 bearing steel have been studied at room temperature and 400°C respectively using a ball on disc machine. Surface profiler

    J. Hardell; B. Prakash

    2010-01-01

    338

    THERM Simulations of Window Indoor Surface Temperatures for Predicting Condensation  

    SciTech Connect

    As part of a ''round robin'' project, the performance of two wood windows and a Calibrated Transfer Standard was modeled using the THERM heat-transfer simulation program. The resulting interior surface temperatures can be used as input to condensation resistance rating procedures. The Radiation and Condensation Index features within THERM were used to refine the accuracy of simulation results. Differences in surface temperatures between the ''Basic'' calculations and those incorporating the Radiation and/or Condensation Index features are demonstrated and explained.

    Kohler, Christian; Arasteh, Dariush; Mitchell, Robin

    2001-05-18

    339

    Earth and Moon Viewer  

    NSDL National Science Digital Library

    At this site you can view either a map of the Earth showing the day and night regions at this moment, or view the Earth from the Sun, the Moon, the night side of the Earth, above any location on the planet specified by latitude, longitude and altitude, from a satellite in Earth orbit, or above various cities around the globe. Images can be generated based on a full-colour image of the Earth by day and night, a topographical map of the Earth, up-to-date weather satellite imagery, or a composite image of cloud cover superimposed on a map of the Earth, or a color composite which shows clouds, land and sea temperatures, and ice. In addition to the Earth, you can also view the Moon from the Earth, Sun, night side, above named formations on the lunar surface or as a map showing day and night. A related document compares the appearance of the Moon at perigee and apogee, including an interactive Perigee and Apogee Calculator.

    Walker, John

    1999-03-27

    340

    Land-Surface Temperature Changes on the High-Latitudes of the Northern Hemisphere and Permafrost Biosequestration Stability  

    NASA Astrophysics Data System (ADS)

    Radiant solar energy and water are fundamental to life on Earth. Water through its heat capacity can re-distribute heat over the land-surface and within the near sub-surface. The stability of permafrost is affected by changes in land-surface temperature and snow cover. We investigate land-surface energy change effects using the NASA Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA-Terra. We utilize land-surface temperature (morning overpasses, clear-sly conditions) MOD11A3 version 5 datasets from March 2000 through April 2010. Our analysis focuses land-surface temperatures and changes on the 65N polar region. We divide the 65N region into a triad of 120-degree sectors enclosing Eurasia, Far East Russia - Western North America and Northeastern North American - Northwestern Europe. Over the 10-year period changes in land-surface temperature, particularly changes in the number of days above and below 0-degree Celsius can be detected. On lands 65N and above during 2000 the number of days above 0 degrees C is 97 and during 2010 is 111, an increase of 14 days in 10 years. Land-surface temperatures during 2010 show an increase of 2.1 +/- 0.2 degrees C (P-value 0.01), on average from those during 2000 with a regression R-square of 0.97. Increase of land-surface temperature in boreal winter and summer are factors in permafrost stability and biosequestration changes.

    Muskett, R. R.

    2012-04-01

    341

    Variations in the corneal surface temperature with contact lens wear.  

    PubMed

    This paper presents the two-dimensional simulation of heat propagation in the human eye model during contact lens wear with finite element analysis. Three types of contact lens are studied: Lotrafilcon A, Balafilcon A, and Etafilcon A. The models are solved for both steady and transient solutions. The corneal surface temperature during contact lens wear is found to decrease (average, 0.52 +/- 0.05 degrees C compared with a bare cornea for all lens types). A contact lens with a higher water content has a lower steady state temperature than a contact lens with a lower water content does. Various initial temperatures for the contact lens are found to affect the first 400 s of the temperature variation. When the initial temperature is lower than the corneal temperature, a reduction in temperature is observed during contact lens insertion while the opposite is observed when the initial temperature is higher than the corneal temperature. The increase in evaporation rate when a contact lens is worn increases the cooling effect on the ocular surface. This is suggested to be the cause of lower corneal surface temperature when wearing a contact lens. PMID:17605391

    Ooi, E H; Ng, E Y K; Purslow, C; Acharya, R

    2007-05-01

    342

    The Pilbara: one Billion Years of the Early Evolution of Earth's Surface Environments and Life  

    NASA Astrophysics Data System (ADS)

    The Pilbara contains the most complete sequence of sedimentary and volcanic rocks dating from 3.5 to 2.4 Ga. Because many of these rocks have experienced only low-grade metamorphism it is our best available natural laboratory for studying the origins and early evolution of life on Earth (and other planets) and the environments it inhabited. Indeed discoveries of the oldest possible microfossils, stromatolites and molecular fossils, as well as key mineral, geochemical and isotopic evidence of surface environments and the biosphere have all been reported from Pilbara rocks. Unfortunately complex geology and deep weathering (since the Mesozoic) makes interpretation of some of this record ambiguous leading to heated debates over evidence for life and environmental conditions. It is not surprising then that the first stages of the Astrobiology Drilling Program have been drilled in the Pilbara to obtain samples of sedimentary rocks unaffected by modern weathering. The drill cores potentially provide the best evidence yet of when and how life evolved on Earth, the nature of the environments it inhabited and a template for evaluating possible evidence of life from Mars and other planets. This talk will briefly outline the evolution of the Pilbara as one of the Earth's first continents and the interpreted environmental settings of the range of sites being drilled by the Archean Biosphere and Deep Time Drilling Programs. These include 3.52 to 2.5 Ga submarine and lacustrine black shales, 3.45 Ga deep- and shallow-marine banded cherts, 2.72 Ga stromatolite reefs, an interpreted 2.76 Ga paleosol, and banded iron formations.

    Barley, M. E.

    2004-12-01

    343

    The tidal displacement field at Earth's surface determined using global GPS observations  

    NASA Astrophysics Data System (ADS)

    We investigate the 3-D tidal displacement field on Earth's surface recorded globally by 456 continuous global positioning system (GPS) stations of IGS spanning 1996-2011, for eight principal diurnal and semidiurnal tidal constituents. In-phase and quadrature amplitudes of the residual tidal displacements, after removal of an a priori body tide model, are estimated using the precise point positioning (PPP) technique on the daily GPS data; the resultant daily estimates are combined to derive final estimates for each tide at each station. The results are compared with the predictions of eight recent global ocean tide models, separately for coastal (307) and inland (149) stations. We show that GPS can provide tidal displacement estimates accurate to the level of 0.12 mm (horizontal) and 0.24 mm (vertical) for the lunar-only constituents (M2, N2, O1, and Q1) and less favorably for solar-related tidal constituents (S2, K2, K1, and P1), although improved by ambiguity resolution. Most recent ocean tide models fit the GPS estimates equally well on the global scale but do not agree well between them in certain coastal areas, especially for the vertical displacements, suggesting the existence of model uncertainties near shallow seas. The tidal residuals for the inland stations after removing both body tides and ocean tidal loading (OTL) furthermore show clear continental-scale spatial coherence, implying deficiencies of the a priori body tide modeling in catching lateral heterogeneity in elastic as well as inelastic properties in the Earth's deep interior. We assert that the GPS tidal displacement estimates now achieve sufficient accuracy to potentially provide constraints on the Earth's structure.

    Yuan, Linguo; Chao, Benjamin Fong; Ding, Xiaoli; Zhong, Ping

    2013-05-01

    344

    Satellite Measurements of Sea Surface Temperature Through Clouds  

    Microsoft Academic Search

    Measurements of sea surface temperature (SST) can be made by satellite microwave radiometry in all weather conditions except rain. Microwaves penetrate clouds with little attenuation, giving an uninterrupted view of the ocean surface. This is a distinct advantage over infrared measurements of SST, which are obstructed by clouds. Comparisons with ocean buoys show a root mean square difference of about

    Frank J. Wentz; Chelle Gentemann; Deborah Smith; Dudley Chelton

    2000-01-01

    345

    Global surface-temperature responses to major volcanic eruptions  

    Microsoft Academic Search

    A previous study showed that significant surface cooling occurs over the landmasses of the northern hemisphere in the first few months after a major eruption in that hemisphere. That work is extended here using new surface-air temperature compilations based on land and marine data for both the northern and southern hemispheres. The results indicate that major northern hemisphere eruptions have

    C. B. Sear; P. M. Kelly; P. D. Jones; C. M. Goodess

    1987-01-01

    346

    Charge Structures Interaction in Low Temperature STM Surface Investigations.  

    National Technical Information Service (NTIS)

    In this work we present the results of low-temperature STM investigation of A(subiii)B(subv) semiconductors surface in situ cleaved along (110) plane. On topographic STM images we have found surface charge structures. The possibility of their observation ...

    A. Depuydt C. Van Has N. S. Maslova S. V. Savinov V. I. Panov

    1998-01-01

    347

    Correlation between burning surface temperature and regression rate for polymethylmethacrylate  

    Microsoft Academic Search

    Prediction of the regression rate of polymeric fuels is important, especially for the optimal design of solid fuel ramjets or hybrid rocket motors. The burning surface temperature and the surface activation energy in the Arrhenius pyrolysis equation are required for prediction of the regression rate. As a typical polymeric fuel, polymethylmethacrylate (PMMA) was chosen for the present study. The burning

    Atsushi Ishihara; Yukio Sakai; Katsuyuki Konishi; Eiichi Andoh

    2005-01-01

    348

    Distribution of UV radiation at the Earth's surface from TOMS-measured UV-backscattered radiances  

    NASA Astrophysics Data System (ADS)

    Daily global maps of monthly integrated UV-erythemal irradiance (290-400 nm) at the Earth's surface are estimated using the ozone amount, cloud transmittance, aerosol amounts, and surface reflectivity from the solar UV radiation backscattered from the Earth's atmosphere as measured by the total ozone mapping spectrometer (TOMS) and independently measured values of the extraterrestrial solar irradiance. The daily irradiance values at a given location show that short-term variability (daily to annual) in the amount of UV radiation, 290-400 nm, reaching the Earth's surface is caused by (1) partially reflecting cloud cover, (2) haze and absorbing aerosols (dust and smoke), and (3) ozone. The reductions of UV irradiance estimated from TOMS data can exceed 50 ± 12% underneath the absorbing aerosol plumes in Africa and South America (desert dust and smoke from biomass burning) and exceeded 70 ± 12% during the Indonesian fires in September 1997 and again during March 1998. Recent biomass burning in Mexico and Guatemala have caused large smoke plumes extending into Canada with UV reductions of 50% in Mexico and 20% in Florida, Louisiana, and Texas. Where available, ground-based Sun photometer data show similar UV irradiance reductions caused by absorbing aerosol plumes of dust and smoke. Even though terrain height is a major factor in increasing the amount of UV exposure compared to sea level, the presence of prolonged clear-sky conditions can lead to UV exposures at sea level rivaling those at cloudier higher altitudes. In the equatorial regions, ±20°, the UV exposures during the March equinox are larger than during the September equinox because of increased cloudiness during September. Extended land areas with the largest erythemal exposure are in Australia and South Africa where there is a larger proportion of clear-sky days. The large short-term variations in ozone amount which occur at high latitudes in the range ±65° cause changes in UV irradiance comparable to clouds and aerosols for wavelengths between 280 nm and 300 nm that are strongly absorbed by ozone. The absolute accuracy of the TOMS monthly erythemal exposure estimates over a TOMS field of view is within ±6%, except under UV-absorbing aerosol plumes (dust and smoke) where the accuracy is within ±12%. The error caused by aerosols can be reduced if the height of the aerosol plume is more accurately known. The TOMS estimated irradiances are compared with ground-based Brewer spectroradiometer data obtained at Toronto, Canada. The Brewer irradiances are systematically 20% smaller than TOMS irradiance estimates during the summer months. An accounting of systematic errors brings the Brewer and TOMS irradiances into approximate agreement within the estimated instrumental uncertainties for both instruments.

    Herman, J. R.; Krotkov, N.; Celarier, E.; Larko, D.; Labow, G.

    1999-05-01

    349

    Magma ascent and effusion from a tensile fracture propagating to the Earth's surface  

    NASA Astrophysics Data System (ADS)

    An effusive volcanic eruption results from a sequence of different processes, such as the pressurization of a magma chamber, the propagation of a dyke and the flow of lava at the Earth' surface. The aim of this paper is to establish relationships between the different quantities describing such processes. We consider a spherical magma chamber filled with a low-viscosity magma and included in a homogeneous and isotropic elastic half-space. We assume that, as a result of the inflow of fresh magma or a phase transition, the pressure in the chamber increases slowly during a finite time interval. Assuming that the pressure increase is linear in time, we calculate the stress field generated in the surrounding medium considering the chamber as a centre of dilation. We assume that a vertical tensile fracture originates at the top of the magma chamber after the rock strength is exceeded. The fracture is assumed to propagate quasi-statically along a vertical plane, driven by the stress distribution: both the cases of positive and negative buoyancy force are considered. The problem is solved in two dimensions by considering the fracture as a tensile Somigliana dislocation and expanding the associated stress release into Chebyshev polynomials. The fracture may reach the Earth's surface or not, depending on the depth and radius of the magma chamber, the rate and duration of pressure increase, the rock and magma densities and the rock strength. When the fracture reaches the Earth's surface, we assume that it becomes a vertical conduit. Magma pours out from the vent, driven by the pressure gradient in the conduit. Under the assumption of laminar flow of a Newtonian fluid, we evaluate the initial effusion rate as a function of the relevant model parameters. The flow rate is found to be a non-linear function of the density contrast. We also establish a relationship between the flow rate in the conduit and the initial thickness of the ensuing lava flow, in the case of effusion on a steep slope.

    Santini, Stefano; Tallarico, Andrea; Dragoni, Michele

    2011-08-01

    350

    Temperature trends at the surface and in the troposphere  

    Microsoft Academic Search

    This paper incorporates the latest improvements in intersatellite calibration, along with a new statistical technique, to determine the diurnal and seasonal cycles and climatic trends of 1978–2004 tropospheric temperature using Microwave Sounding Unit measurements. We also compare the latitudinal distribution of temperature trends from the surface and troposphere with each other and with model simulations for the past 26 years.

    Konstantin Y. Vinnikov; Norman C. Grody; Alan Robock; Ronald J. Stouffer; Philip D. Jones; Mitchell D. Goldberg

    2006-01-01

    351

    The effect of deforestation on ground surface temperatures  

    Microsoft Academic Search

    Recorded ground surface temperatures (GSTs) over a period of a year at closely spaced sites in a temperate area (almost no snow or ground freezing) show that forested sites and one with a high water table have colder average temperatures relative to other terrains. At sites in southern British Columbia where trees have been logged and in the southern Yukon

    Trevor Lewis

    1998-01-01

    352

    Southern Hemisphere surface air temperature variations: 1851--1984  

    Microsoft Academic Search

    A new compilation of monthly mean surface air temperature data for the Southern Hemisphere for 1851--1984 is presented based on land-based meteorological station data. Where possible, the station data used in the analysis have been assessed for homogeneity. Only reliable or corrected station data have been used in calculating area averages. Grid point temperature estimates have been made by interpolating

    P. D. Jones; S. C. B. Raper; T. M. L. Wigley

    1986-01-01

    353

    Surface Gravity and Hawking Temperature from Entropic Force Viewpoint  

    Microsoft Academic Search

    We consider a freely falling holographic screen for the Schwarzschild and Reissner-Nordström black holes and evaluate the entropic force à la Verlinde. When the screen crosses the event horizon, the temperature of the screen agrees to the Hawking temperature and the entropic force gives rise to the surface gravity for both of the black holes.

    T. Aaltonen; J. Adelman; B. Álvarez González; S. Amerio; D. Amidei; A. Anastassov; A. Annovi; J. Antos; G. Apollinari; J. Appel; A. Apresyan; T. Arisawa; A. Artikov; J. Asaadi; W. Ashmanskas; A. Attal; A. Aurisano; F. Azfar; W. Badgett; A. Barbaro-Galtieri; V. E. Barnes; B. A. Barnett; P. Barria; P. Bartos; G. Bauer; P.-H. Beauchemin; F. Bedeschi; D. Beecher; S. Behari; G. Bellettini; J. Bellinger; D. Benjamin; A. Beretvas; A. Bhatti; M. Binkley; D. Bisello; I. Bizjak; R. E. Blair; C. Blocker; B. Blumenfeld; A. Bocci; A. Bodek; V. Boisvert; D. Bortoletto; J. Boudreau; A. Boveia; B. Brau; A. Bridgeman; L. Brigliadori; C. Bromberg; E. Brubaker; J. Budagov; H. S. Budd; S. Budd; K. Burkett; G. Busetto; P. Bussey; A. Buzatu; K. L. Byrum; S. Cabrera; C. Calancha; S. Camarda; M. Campanelli; M. Campbell; F. Canelli; A. Canepa; B. Carls; D. Carlsmith; R. Carosi; S. Carrillo; S. Carron; B. Casal; M. Casarsa; A. Castro; P. Catastini; D. Cauz; V. Cavaliere; M. Cavalli-Sforza; A. Cerri; L. Cerrito; S. H. Chang; Y. C. Chen; M. Chertok; G. Chiarelli; G. Chlachidze; F. Chlebana; K. Cho; D. Chokheli; J. P. Chou; K. Chung; W. H. Chung; Y. S. Chung; T. Chwalek; C. I. Ciobanu; M. A. Ciocci; A. Clark; D. Clark; G. Compostella; M. E. Convery; J. Conway; M. Corbo; M. Cordelli; C. A. Cox; D. J. Cox; F. Crescioli; C. Cuenca Almenar; J. Cuevas; R. Culbertson; J. C. Cully; D. Dagenhart; N. D'Ascenzo; M. Datta; T. Davies; P. de Barbaro; S. de Cecco; A. Deisher; G. de Lorenzo; M. Dell'Orso; C. Deluca; L. Demortier; J. Deng; M. Deninno; M. D'Errico; A. di Canto; B. di Ruzza; J. R. Dittmann; M. D'Onofrio; S. Donati; P. Dong; T. Dorigo; S. Dube; K. Ebina; A. Elagin; R. Erbacher; D. Errede; S. Errede; N. Ershaidat; R. Eusebi; H. C. Fang; S. Farrington; W. T. Fedorko; R. G. Feild; M. Feindt; J. P. Fernandez; C. Ferrazza; R. Field; G. Flanagan; R. Forrest; M. J. Frank; M. Franklin; J. C. Freeman; I. Furic; M. Gallinaro; J. Galyardt; F. Garberson; J. E. Garcia; A. F. Garfinkel; P. Garosi; H. Gerberich; D. Gerdes; A. Gessler; S. Giagu; V. Giakoumopoulou; P. Giannetti; K. Gibson; J. L. Gimmell; C. M. Ginsburg; N. Giokaris; M. Giordani; P. Giromini; M. Giunta; G. Giurgiu; V. Glagolev; D. Glenzinski; M. Gold; N. Goldschmidt; A. Golossanov; G. Gomez; G. Gomez-Ceballos; M. Goncharov; O. González; I. Gorelov; A. T. Goshaw; K. Goulianos; A. Gresele; S. Grinstein; C. Grosso-Pilcher; U. Grundler; J. Guimaraes da Costa; Z. Gunay-Unalan; C. Haber; S. R. Hahn; E. Halkiadakis; B.-Y. Han; J. Y. Han; F. Happacher; K. Hara; D. Hare; M. Hare; R. F. Harr; M. Hartz; K. Hatakeyama; C. Hays; M. Heck; J. Heinrich; M. Herndon; J. Heuser; S. Hewamanage; D. Hidas; C. S. Hill; D. Hirschbuehl; A. Hocker; S. Hou; M. Houlden; S.-C. Hsu; R. E. Hughes; M. Hurwitz; U. Husemann; M. Hussein; J. Huston; J. Incandela; G. Introzzi; M. Iori; A. Ivanov; E. James; D. Jang; B. Jayatilaka; E. J. Jeon; M. K. Jha; S. Jindariani; W. Johnson; M. Jones; K. K. Joo; S. Y. Jun; J. E. Jung; T. R. Junk; T. Kamon; D. Kar; P. E. Karchin; Y. Kato; R. Kephart; W. Ketchum; J. Keung; B. Kietzman; V. Khotilovich; B. Kilminster; D. H. Kim; H. S. Kim; H. W. Kim; J. E. Kim; M. J. Kim; S. B. Kim; S. H. Kim; Y. K. Kim; N. Kimura; L. Kirsch; S. Klimenko; K. Kondo; D. J. Kong; J. Konigsberg; A. Korytov; A. V. Kotwal; M. Kreps; J. Kroll; D. Krop; N. Krumnack; M. Kruse; V. Krutelyov; T. Kuhr; N. P. Kulkarni; M. Kurata; S. Kwang; A. T. Laasanen; S. Lami; S. Lammel; M. Lancaster; R. L. Lander; K. Lannon; A. Lath; G. Latino; I. Lazzizzera; T. Lecompte; E. Lee; H. S. Lee; J. S. Lee; S. W. Lee; S. Leone; J. D. Lewis; C.-J. Lin; J. Linacre; M. Lindgren; E. Lipeles; A. Lister; D. O. Litvintsev; C. Liu; T. Liu; N. S. Lockyer; A. Loginov; L. Lovas; D. Lucchesi; J. Lueck; P. Lujan; P. Lukens; G. Lungu; J. Lys; R. Lysak; D. MacQueen; R. Madrak; K. Maeshima; K. Makhoul; P. Maksimovic; S. Malde; S. Malik; G. Manca; A. Manousakis-Katsikakis; F. Margaroli; C. Marino; A. Martin; V. Martin; M. Martínez; R. Martínez-Ballarín; P. Mastrandrea; M. Mathis; M. E. Mattson; P. Mazzanti; K. S. McFarland; P. McIntyre; R. McNulty; A. Mehta; P. Mehtala; A. Menzione; C. Mesropian; T. Miao; D. Mietlicki; N. Miladinovic; R. Miller; C. Mills; M. Milnik; A. Mitra; G. Mitselmakher; H. Miyake; S. Moed; N. Moggi; M. N. Mondragon; C. S. Moon; R. Moore; M. J. Morello; J. Morlock; P. Movilla Fernandez; J. Mülmenstädt; A. Mukherjee; Th. Muller; P. Murat; M. Mussini; J. Nachtman; Y. Nagai; J. Naganoma; K. Nakamura; I. Nakano; A. Napier; J. Nett; C. Neu; M. S. Neubauer; S. Neubauer; J. Nielsen; L. Nodulman; M. Norman; O. Norniella; E. Nurse; L. Oakes; S. H. Oh; Y. D. Oh; I. Oksuzian; T. Okusawa; R. Orava; K. Osterberg; S. Pagan Griso; C. Pagliarone; E. Palencia; V. Papadimitriou; A. Papaikonomou; A. A. Paramanov; B. Parks; S. Pashapour; J. Patrick; G. Pauletta; M. Paulini; C. Paus; T. Peiffer; D. E. Pellett; A. Penzo

    2010-01-01

    354

    Measurements of Shocked Metal Surface Temperatures using Multichannel Optical Pyrometry  

    NASA Astrophysics Data System (ADS)

    A multichannel optical pyrometer has been used to measure the shocked metal surface temperature of various metals including tantalum. Transparent anvils of LiF and sapphire were used to hold the metal-anvil interface at high pressure. These results are analyzed to produce temperatures and dynamic emissivities as a function of wavelength. These results are discussed and compared to current EOS predictions.

    Holtkamp, David B.

    1999-06-01

    355

    Scale Effect of Surface Area on the Temperature of the Ground Surface  

    NASA Astrophysics Data System (ADS)

    In 1980s, the satellite observations revealed that the daytime surface temperatures of the urban areas were very high compared with the rural area and the heat island was distinct in the daytime (Goward 1981, Carlson et al. 1981). The air temperature, however, shows distinct heat island in the night time and the heat island of the air temperature in the daytime is not significant. This has been a mystery of the urban climate and it has been attributed to the complicated urban structures (Roth et al. 1989, Arnfield 2003, Voogt and Oke 2003). This paper proposes a very simple mechanism which explains this old mystery. The surfaces of the urban areas are covered by large flat surfaces such as roads and walls of buildings while those of the rural areas are covered by many plants which have many small leaves. This difference in the surface geometry, especially the size of the surface area, has great impact on the temperature of the ground surface. To demonstrate the scale effect to the surface temperature, we made some fractal sunshades consist of many small "leaves" and placed under sunshine. The results showed that the fractal sunshade reduced the ground temperature without being heated themselves. The results indicate we can reduce urban ground surface temperature by changing geometry of the surface without using water.

    Sakai, S.; Onishi, M.; Nakamura, M.; Furuya, K.

    2011-12-01

    356

    About the temperature, pressure and viscosity distributions in the Earth's mantle on it's accumulation.  

    NASA Astrophysics Data System (ADS)

    Geological Earths evolution significantly depends from its initial origin. In the paper [1] we suggested a new accumulation model of planets of terrestrial group, which use the modern estimations of concentration of short-living natural radioactive isotopes in the matter of the proto planet cloud. It had been qualitative new estimations of temperature distributions in the growing pre planets in the Earth "feed" zone. For the velocity of proto planet mass increasing we use the model of Safronov. The temperature distribution in the body with the increasing radius is obtained numerically using the solution of the boundary problem for the equation of thermal conductivity with account a possibility of melt occurring without explicit marking of the boundary of crystallization front and parametrical account of convective heat transfer in the melt [2]. It is shown, that in proto planet bodies with dimensions about 100km in the main part of the inner area the temperatures achieve higher that the iron melting temperature. On that stage the relative bodies impact velocities are sufficient for crashing the upper brittle envelope and support the coupling of the inner melted parts. The mass of the growing proto planet is not sufficient to merge the mainly silicate envelope fragments. So on the stage of bodies coupling with radiuses (100-500) km it could occur the effective separation of the W-Hf system between the melted iron and cold silicate reservoirs during the period, which satisfy the experimental data a period equal to or less 10 million years. In that model on the growing stage of the iron core the impacts occur inelastic. The main gravitational potential energy transfers into the heat energy and accumulates by the planet. By the increasing of core mass the gravitational radius increases and it can keep the increasing part of cold silicate fragments. The impacts become more elastic and the less part of potential energy transfers into the heat energy. By solution of the boundary for heat balance it is needed to calculate the distribution of the pressure and matter viscosity, because the viscosity distribution depends from the intensity of convective heat transfer. Additionally using known estimations the matter viscosity significantly depends from the content, temperature and pressure. By numerical modeling on each step by time we had defined a new density distribution. Then we calculated a new distribution of litho static pressure and melting pressure. Then for different model relations for viscosity from temperature and pressure we define the viscosity distribution and calculate the effective thermal conductivity, which approximate the convective heat transfer. Then we calculate the new temperature distribution. As results we had obtained a set of possible changing of viscosity and temperature in the mantle matter with depth during the accumulation process. References 1.Anfiligov V.N., Khachay Yu.V. DAN. 2005, V. 403, ? 6, P. 803-806. 2. Khachay Yu.V, Anfilogov V.N. // Geophysical Research Abstracts, v.11.EGU2009-3702-1, 2009. EGU General Assembly 2009.

    Khachay, Yurie; Anfilogov, Vsevolod

    2010-05-01

    357

    Grain surface-layer treatment of diatomaceous earth for insect control.  

    PubMed

    This paper describes an alternative method to synthetic insecticides used for protection of stored agricultural products the purpose of which is to minimise the everyday human exposure to those chemicals. The method uses diatomaceous earth which is practically non-toxic to humans and fully acceptable for the environment. Fifty and 100-cm-deep layers of Hard Red Spring wheat Triticum aestivum (L.) in metal containers (cylinders), 30 cm in diameter and 150 cm in height were treated with 0.5 and 0.75 g of diatomaceous earth Protect-It per kg of wheat. The treatment reduced the population of Sitophilus oryzae (L.), Tribolium castaneum (Herbst) and Rhyzopertha dominica (Fabricius) by 98 to 100% with respect to controls. The conclusion is that a 100-cm-surface layer treated with 0.5 g/kg of Protect-It is sufficient to control these insects, and that no more than 20% of the total grain mass should be treated to minimise bulk density reduction. A field test using a similar design is essential to confirm the laboratory findings. PMID:11059067

    Koruni?, Z; Mackay, A

    2000-03-01

    358

    On long range dependence in global surface temperature series  

    Microsoft Academic Search

    Long Range Dependence (LRD) scaling behavior has been argued to characterize long-term surface temperature time series. LRD\\u000a is typically measured by the so-called “Hurst” coefficient, “H”. Using synthetic temperature time series generated by a simple climate model with known physics, I demonstrate that the\\u000a values of H obtained for observational temperature time series can be understood in terms of the

    Michael E. Mann

    2011-01-01

    359

    Impervious surfaces and sewer pipe effects on stormwater runoff temperature  

    NASA Astrophysics Data System (ADS)

    Investigated effect of impervious surfaces and sewer pipe on runoff temperature.Four urban catchment areas were monitored for three summers 2009-2011.An artificial neural network model was trained and validated using monitoring data.IMP increase from 20% to 50% resulted in runoff temperature increase by 3 °C.LPL increase from 345 to 966 m resulted in runoff temperature drop by 2.5 °C.

    Sabouri, F.; Gharabaghi, B.; Mahboubi, A. A.; McBean, E. A.

    2013-10-01

    360

    The sub-surface magnetic fields produced by a line current source on a non-flat earth  

    Microsoft Academic Search

    A simple cylindrical model is employed to estimate the effect of non-flatness of the ground on the sub-surface electromagnetic field from a current-carrying cable on the surface. It is shown that, if the surface curvature is sufficiently small, the fields in the cylinder model are very similar to those for the conducting half-space model of the earth employed earlier. The

    James R. Wait; R. E. Wilkerson

    1972-01-01

    361

    Surface tension of aqueous binary solutions at low temperatures  

    Microsoft Academic Search

    The paper is concerned with measurements of the surface tension of aqueous binary solutions at low temperatures. The effects\\u000a of both temperature and concentration on the surface tension of CaCl2, NaClO3, and propylene glycol have been investigated. A differential capillary-rise method was employed for the measurements. The\\u000a results showed that the surface tension of CaCl2 and NaClO3 increases monotonically as

    A. Horibe; S. Fukusako; M. Yamada; K. Fumoto

    1997-01-01

    362

    The molecular signal for the adaptation to cold temperature during early life on Earth.  

    PubMed

    Several lines of evidence such as the basal location of thermophilic lineages in large-scale phylogenetic trees and the ancestral sequence reconstruction of single enzymes or large protein concatenations support the conclusion that the ancestors of the bacterial and archaeal domains were thermophilic organisms which were adapted to hot environments during the early stages of the Earth. A parsimonious reasoning would therefore suggest that the last universal common ancestor (LUCA) was also thermophilic. Various authors have used branch-wise non-homogeneous evolutionary models that better capture the variation of molecular compositions among lineages to accurately reconstruct the ancestral G + C contents of ribosomal RNAs and the ancestral amino acid composition of highly conserved proteins. They confirmed the thermophilic nature of the ancestors of Bacteria and Archaea but concluded that LUCA, their last common ancestor, was a mesophilic organism having a moderate optimal growth temperature. In this letter, we investigate the unknown nature of the phylogenetic signal that informs ancestral sequence reconstruction to support this non-parsimonious scenario. We find that rate variation across sites of molecular sequences provides information at different time scales by recording the oldest adaptation to temperature in slow-evolving regions and subsequent adaptations in fast-evolving ones. PMID:24046876

    Groussin, Mathieu; Boussau, Bastien; Charles, Sandrine; Blanquart, Samuel; Gouy, Manolo

    2013-10-23

    363

    Numerical Simulation of Earth Directed CMEs with an Advanced Two-Temperature Coronal Model (Invited)  

    NASA Astrophysics Data System (ADS)

    We present progress on modeling Earth-directed CMEs including the December 12, 2008 CME and the May 13, 2005 campaign event from initiation to heliospheric propagation. Our earlier work on the 2005 event followed the CME to the orbit of Saturn employing the coronal model of Cohen et al. (2007), which relies on a spatially varying adiabatic index (gamma) to produce the bimodal solar wind. This model was able to reproduce several features of the observed event, but suffered from artifacts of the artificially thermodynamics. We will examine results of a recent simulation performed with a new two-temperature solar corona model developed at the University of Michigan. This model employs heat conduction for both ion and electron species, constant adiabatic index (=5/3), and includes Alfven waves to drive the solar wind. The model includes SOHO/MDI magnetogram data to calculate the coronal field, and also uses SOHO/EIT observations to specify the density and temperature at the coronal boundary by the Differential Emission Measure Tomography (DEMT) method. The Wang-Sheeley-Arge empirical model is used to determine the Alfven wave pressure necessary to produce the observed solar wind speeds. We find that the new model is much better able to reproduce the solar wind densities, and also correctly captures the compression at the CME-driven shock due to the fixed adiabatic index.

    Manchester, W. B.; van der Holst, B.; Frazin, R. A.; Vasquez, A. M.; Toth, G.; Gombosi, T. I.

    2010-12-01

    364

    Ionospheric generation mechanism of geomagnetic pulsations observed on the Earth's surface before earthquake  

    NASA Astrophysics Data System (ADS)

    New generation mechanism of ULF geomagnetic oscillations observed on the Earth's surface in seismic zones is presented. This mechanism is based on the formation of periodic structure of ionospheric conductivity due to acoustic-gravity wave instability stimulated by DC electric field enhancement in the ionosphere. Interaction of the background electromagnetic ULF waves with such structure leads to an excitation of polarization currents and generation of narrow band gyrotropic waves at the 0.1-10Hz frequency range in the ionosphere. The magnetic field of these waves can be observed on the ground. Since the growth of seismic activity is often accompanied by DC electric field enhancement on the ground and in the ionosphere, the suggested mechanism can be considered as a possible source of the seismogenic geomagnetic pulsations generated before and during earthquakes.

    Sorokin, V. M.; Chmyrev, V. M.; Yaschenko, A. K.

    2003-01-01

    365

    Nonlinear attenuation of pulsed laser radiation on an atmospheric path near the earth surface  

    NASA Astrophysics Data System (ADS)

    Experimental results are presented concerning the propagation of a collimated beam of pulsed CO2-laser radiation with a pulse duration of 40 microsec and an energy density up to 10 J/sq cm on an atmospheric path 40 m long and 2 m above the earth surface. A mechanism explaining the anomalous attenuation of the radiation in the course of a pulse is presented. After rapid heating of aerosol particles after the beginning of the pulse, the explosion of one of the chemical fractions of finely disperse aerosol occurs, with the formation of thermal irregularities of the medium, leading to radiation scattering. Owing to thermal heat conduction, the optical density of the medium is then restored and the path transmissivity increases.

    Blinov, N. A.; Leontev, I. A.; Ryzhkov, E. G.; Semenov, V. L.; Sinelnikov, V. P.

    1985-10-01

    366

    Spintronics: Towards room temperature ferromagnetic devices via manganese and rare earth doped gallium nitride  

    NASA Astrophysics Data System (ADS)

    Spintronics is a multidisciplinary field aimed at the active manipulation of spin degrees of freedom in solid-state systems. The goal being the understanding of the interaction between the particle spin and its solid-state environment, and the making of useful devices based on the acquired knowledge. If Moore's law is to continue, then we need to find alternatives to conventional microelectronics. Where conventional electronic devices rely on manipulating charge to produce desired functions, spintronic devices would manipulate both the charge flow and electron spin within that flow. This would add an extra degree of freedom to microelectronics and usher in the era of truly nanoelectronic devices. Research aimed at a whole new generation of electronic devices is underway by introducing electron spin as a new or additional physical variable, and semiconductor devices that exploit this new freedom will operate faster and more efficiently than conventional microelectronic devices and offer new functionality that promises to revolutionize the electronics industry. Long recognized as the material of choice for next-generation solid-state lighting, gallium nitride (GaN) also has proven uses in the field of high power, high frequency field-effect transistors (FETs). But its promise as a material system for spintronic applications may be its ultimate legacy. In this dissertation, the growth of gallium-manganese-nitride (GaMnN) compound semiconductor alloy was investigated through the use of an in-house built metal-organic chemical vapor deposition (MOCVD) reactor. Building on previous investigations of ferromagnetic mechanisms in GaMnN, where ferromagnetism was shown to be carrier mediated, a above room temperature ferromagnetic GaMnN i-p-n diode structure was conceived. This device proved to be the first of its kind in the world, where ferromagnetic properties are controlled via proximity of the mediating holes, upon voltage bias of adjacent structure layers. Simultaneously, post-growth diffusion of ferromagnetic, rare earth species into GaN template thin films also was investigated. Structural, electrical, optical and magnetic characterization of diffused films grown on sapphire was performed. Optimization of the conditions leading to the first successful diffusion of neodymium into GaN thin films, and the magnetic and optical studies that followed are detailed. A mechanism governing and conditions promoting ferromagnetism in rare earth (RE) doped GaN is proposed. The magnetic relationship between two similar and dissimilar rare earth elements, in a single GaN crystal are investigated. Finally, spin valve and magnetic tunnel junction devices based on the magnetic properties of RE-GaN thin films are investigated.

    Luen, Melvyn Oliver

    367

    Surface and gas phase temperatures of a tungsten coil atomizer  

    NASA Astrophysics Data System (ADS)

    The electrothermal atomization of elements is critically affected by the volatility of the analyte and its compounds, the matrix constituents, the atomizer material and the surface and gas phase temperatures. There are scarce temperature data about the tungsten coil atomizer (TCA). This paper involves measurements of surface and gas phase temperatures of a TCA (Osram 150 W). Three strategies were adopted to assess the surface temperature: electric current measurements in each applied voltage to calculate resistivity and correlation of this latter parameter with temperature; melting points of organic and inorganic compounds in the 120-800 °C range, and optical pyrometer measurements in the 1000-3000 °C range. The first two methods led to at least estimate values and more accurate results were attained with the optical pyrometer. The gas phase temperature was estimated based on the two-line absorption method using tin as thermometric element. The data showed a pronounced difference between surface and gas phase temperatures that can reach values higher than 1000 °C depending on the applied voltage and observation height. Data are discussed considering thermochemical processes in a double layer tungsten coiled filament.

    Queiroz, Zilvanir F.; Oliveira, Pedro V.; Nóbrega, Joaquim A.; Silva, C?´ntia S.; Rufini, Iolanda A.; de Sousa, Samuel Simião; Krug, Francisco J.

    2002-11-01

    368

    The impact of land surface temperature on soil moisture anomaly detection from passive microwave observations  

    Microsoft Academic Search

    For several years passive microwave observations have been used to retrieve soil moisture from the Earth's surface. Low frequency observations have the most sensitivity to soil moisture, therefore the current Soil Moisture and Ocean Salinity (SMOS) and future Soil Moisture Active and Passive (SMAP) satellite missions observe the Earth's surface in the L-band frequency. In the past, several satellite sensors

    R. M. Parinussa; T. R. H. Holmes; M. T. Yilmaz; W. T. Crow

    2011-01-01

    369

    The impact of land surface temperature on soil moisture anomaly detection from passive microwave observations  

    Microsoft Academic Search

    For several years passive microwave observations have been used to retrieve soil moisture from the Earth's surface. Low frequency observations have the most sensitivity to soil moisture, therefore the modern Soil Moisture and Ocean Salinity (SMOS) and future Soil Moisture Active and Passive (SMAP) satellite missions observe the Earth's surface in the L-band frequency. In the past, several satellite sensors

    R. M. Parinussa; T. R. H. Holmes; W. T. Crow

    2011-01-01

    370

    Estimating river discharge from earth observation measurements of river surface hydraulic variables  

    NASA Astrophysics Data System (ADS)

    River discharge is a key variable for quantifying the water cycle, its fluxes and stocks at different scales. These scales range from a local scale for the efficient management of water resources to a global scale for the monitoring of climate change. Therefore, developing Earth observation (EO) techniques for the measurement or estimation of river discharge poses a major challenge. A key question deals with the possibility of deriving river discharge values from EO surface variables (width, level, slope, and velocity are the only such variables accessible through EO) without any in situ measurement. Based on a literature study and original investigations, this study explores the possibilities of estimating river discharge from water surface variables. The proposed method relies on limiting assumptions to simplify river flow equations to obtain the values of the hydraulic parameters at a given river station without using ground measurements. Once the hydraulic parameters are identified, the method allows the estimation of the river discharge corresponding to a set of surface measurements of hydraulic variables.

    Negrel, J.; Kosuth, P.; Bercher, N.

    2011-06-01

    371

    Diurnal variations of Titan's surface temperatures from Cassini - CIRS observations  

    NASA Astrophysics Data System (ADS)

    The Cassini Composite Infrared Spectrometer (CIRS) observations of Saturn's largest moon, Titan, are providing us with the ability to detect the surface temperature of the planet by studying its outgoing radiance through a spectral window in the thermal infrared at 19 micron (530 cm-1) characterized by low opacity. Since the first acquisitions of CIRS Titan data the instrument has gathered a large amount of spectra covering a wide range of latitudes, longitudes and local times. We retrieve the surface temperature and the atmospheric temperature profile by modeling proper zonally averaged spectra of nadir observations with radiative transfer computations. Our forward model uses the correlated-k approximation for spectral opacity to calculate the emitted radiance, including contributions from collision induced pairs of CH4, N2 and H2, haze, and gaseous emission lines (Irwin et al. 2008). The retrieval method uses a non-linear least-squares optimal estimation technique to iteratively adjust the model parameters to achieve a spectral fit (Rodgers 2000). We show an accurate selection of the wide amount of data available in terms of footprint diameter on the planet and observational conditions, together with the retrieved results. Our results represent formal retrievals of surface brightness temperatures from the Cassini CIRS dataset using a full radiative transfer treatment, and we compare to the earlier findings of Jennings et al. (2009). The application of our methodology over wide areas has increased the planet coverage and accuracy of our knowledge of Titan's surface brightness temperature. In particular we had the chance to look for diurnal variations in surface temperature around the equator: a trend with slowly increasing temperature toward the late afternoon reveals that diurnal temperature changes are present on Titan surface.

    Cottini, Valeria; Nixon, C. A.; Jennings, D. E.; Anderson, C. M.; Samuelson, R. E.; Irwin, P. G. J.; Flasar, F. M.

    2010-04-01

    372

    Mission to planet earth  

    SciTech Connect

    Plans for environmental monitoring using remote-sensing satellites in the era of the International Space Station are reviewed. The role of international cooperation is stressed, considering the present Landsat, SPOT, and Marine Observation Satellite programs; ERS-1 and Topex/Poseidon; and plans for the Italian Lageos-2, the Indian Remote Sensing Satellite, and the Japanese Advanced Earth Observation Satellite. The NASA Mission to Planet Earth proposal calls for four polar-orbit and five GEO platforms (five NASA, two ESA, and two NASDA), to be in place by the year 2000, as well as dedicated spacecraft of the Earth System Explorer series in the 1990s. Payloads will monitor the geomagnetic field, atmospheric temperature and water vapor, O3 and aerosols, outgoing radiation, precipitation, sea-surface temperature, sea ice, ocean chlorophyll, surface winds, wave height, ocean circulation, snow cover, land use, vegetation, crops, volcanic activity, and the hydrologic cycle.

    Baker, D.J.

    1988-07-01

    373

    Meteoric cosmogenic Beryllium-10 adsorbed to river sediment and soil: Applications for Earth-surface dynamics  

    NASA Astrophysics Data System (ADS)

    Rainfall scavenges meteoric cosmogenic 10Be from the atmosphere. 10Be falls to the Earth's surface, where it binds tightly to sediment particles in non-acidic soils over the life-span of those soils. As such, meteoric 10Be has the potential to be an excellent geochemical tracer of erosion and stability of surfaces in a diverse range of natural settings. Meteoric 10Be has great potential as a recorder of first-order erosion rates and soil residence times. Even though this tracer was first developed in the late 1980s and showed great promise as a geomorphic tool, it was sidelined in the past two decades with the rise of the "sister nuclide", in situ10Be, which is produced at a known rate inside quartz minerals. Since these early days, substantial progress has been made in several areas that now shed new light on the applicability of the meteoric variety of this cosmogenic nuclide. Here, we revisit the potential of this tracer and we summarize the progress: (1) the atmospheric production and fallout is now described by numeric models, and agrees with present-day measurements and paleo-archives such as from rain and ice cores; (2) short-term fluctuations in solar modulation of cosmic rays or in the delivery of 10Be are averaged out over the time scale soils accumulate; (3) in many cases, the delivery of 10Be is not dependent on the amount of precipitation; (4) we explore where 10Be is retained in soils and sediment; (5) we suggest a law to account for the strong grain-size dependence that controls adsorption and the measured nuclide concentrations; and (6) we present a set of algebraic expressions that allows calculation of both soil or sediment ages and erosion rates from the inventory of meteoric 10Be distributed through a vertical soil column. The mathematical description is greatly simplified if the accumulation of 10Be is at a steady state with its export through erosion. In this case, a surface sample allows for the calculation of an erosion rate. Explored further, this approach allows calculation of catchment-wide erosion rates from river sediment, similar to the approach using 10Be produced in situ. In contrast to the in situ10Be approach, however, these analyses can be performed on any sample of fine-grained material, even where no quartz minerals are present. Therefore, this technique may serve as a tool to date sediment where no other chronometer is available, to track particle sources and to measure Earth-surface process rates in soil, suspended river sediment, and fine-grained sedimentary deposits.

    Willenbring, Jane K.; von Blanckenburg, Friedhelm

    2010-01-01

    374

    Observed and model simulated 20th century Arctic temperature variability: Canadian Earth System Model CanESM2  

    Microsoft Academic Search

    We present simulations of the 20th century Arctic temperature anomaly from the second generation Canadian Earth System Model (CanESM2). The new model couples together an atmosphere-ocean general circulation model, a land-vegetation model and terrestrial and oceanic interactive carbon cycle. It simulates well the observed 20th century Arctic temperature variability that includes the early and late 20th century warming periods and

    P. Chylek; J. Li; M. K. Dubey; M. Wang; G. Lesins

    2011-01-01

    375

    Temperature Dependence of Surface Layering in a Dielectric Liquid  

    SciTech Connect

    The temperature dependence of the density oscillations (layers) at the free surface of tetrakis(2-ethylhexoxy)silane, a nonmetallic molecular liquid, was investigated using x-ray reflectivity. Below {approx}215K , the layer parameters weakly vary with temperature, if at all. Above this temperature, the layer spacings and intrinsic layer widths increase continuously, until there is no identifiable layering above 230K . This transition occurs at T/{Tc}{approx}0.23 , a temperature region that is usually accessible in metallic liquids but is preempted by freezing in many dielectric liquids.

    Mo,H.; Kewalramani, S.; Evmenenko, G.; Kim, K.; Ehrlich, S.; Dutta, P.

    2007-01-01

    376

    Geomagnetic effects modelling for the PJM interconnection system. I. Earth surface potentials computation  

    Microsoft Academic Search

    The authors describe an ionospheric source current model and the development of an Earth resistivity model used to calculate geomagnetic induced currents (GIC) on the Pennsylvania-New Jersey-Maryland interconnection (PJM). The ionospheric current was modeled as a Gaussian distributed current sheet above the Earth. Geological details are included by dividing the PJM service area into 11 different Earth resistivity regions. The

    J. N. Towle; F. S. Prabhakara; J. Z. Ponder

    1992-01-01

    377

    Two surface temperature retrieval methods compared over agricultural lands  

    NASA Astrophysics Data System (ADS)

    Accurate, spatially distributed surface temperatures are required for modeling evapotranspiration (ET) over agricultural fields under wide ranging conditions, including stressed and unstressed vegetation. Modeling approaches that use surface temperature observations, however, have the burden of estimating surface emissivities. Emissivity estimation, the subject of much recent research, is facilitated by observations in multiple thermal infrared bands. But it is nevertheless a difficult task. Using observations from multiband thermal sensors, ASTER and MASTER, estimated surface emissivities and temperatures are retrieved in two different ways: the temperature emissivity separation approach (TES), and the normalized emissivity approach (NEM). Both rely upon empirical relationships, but the assumed relationships are different. TES relies upon a relationship between the minimum spectral emissivity and the range of observed emissivities. NEM relies upon an assumption that at least one thermal band has a predetermined emissivity (close to 1.0). Experiments comparing TES and NEM were performed using simulated observations from spectral library data, and with actual data from two different landscapes-- one in central Oklahoma, USA, and another in southern New Mexico, USA. The simulation results suggest that TES's empirical relationship is more realistic than NEM's assumed maximum emissivity, and therefore TES temperature estimates are more accurate than NEM estimates. But when using remote sensing data, TES estimates of maximum emissivities are lower than expected, thus causing overestimated temperatures. Work in progress will determine the significance of this overestimation by comparing ground level measurements against the remote sensing observations.

    French, Andrew; Schmugge, Thomas J.; Jacob, Frederic; Ogawa, Kenta

    2003-03-01

    378

    High-Temperature Mars-to-Earth Transfer of Meteorite ALH84001  

    NASA Astrophysics Data System (ADS)

    Mars is thought to have experienced intense volcanism, impact cratering and fluvial resurfacing during its first ~1.5 Byr, followed by a less-energetic, colder period. Rare meteoritic samples of the Martian crust provide some of the only direct evidence by which to test and develop models of the paleoenvironmental evolution of the planet, its potential habitability by life, and the process of interplanetary mass transport. Thermal histories of Martian meteorites provide crucial evidence bearing not only on long-term, ambient near-surface conditions on Mars, but also on whether meteoroids can be ejected from their large parent bodies without significant heating, a favorable condition for exogenesis (including panspermia) hypotheses. One of the best samples to address these issues is Martian meteorite ALH84001, because it has the oldest crystallization age of ~4.5 Ga, is thought to have resided near the surface since ~4.0 Ga, and has been suggested to have experienced no significant heating during or after its ejection from Mars at 15 Ma. To better constrain the thermal evolution and shock metamorphic history of ALH84001, we applied (U-Th)/He thermochronometry to single grains of merrillite and chlorapatite from ALH84001. The (U-Th)/He ages of individual phosphate grains in ALH84001 range from 60 Ma to 1.8 Ga, with a weighted mean of ~830 Ma. This broad age distribution reflects multiple diffusion domains, and requires a relatively high-temperature resetting event younger than ~60 Ma. These new data are combined with the published whole-rock (maskelynite as a main Ar reservoir) 40Ar/39Ar age spectra which show 5-8 % fractional loss of 40Ar since 4.0 Ga. He diffusion in both terrestrial and extraterrestrial apatite has a significantly higher activation energy (138 ~ 184 kJ/mol) than Ar diffusion in maskelynite (75 kJ/mol), leading to an important "kinetic crossover" in fractional loss contours for these systems. Taken together, the phosphate (U-Th)/He and maskelynite 40Ar/39Ar ages require both very low surface temperatures on Mars, and one or more short-lived, high-temperature, shock events after 4.0 Ga. We suggest that the last shock event occurred with ejection of ALH84001 from Mars, and reached a peak temperature of approximately 400 °C. These results undermine the proposed low-temperature ejection hypothesis for ALH84001, but support long-lived extremely cold Martian surface temperatures.

    Min, K.; Reiners, P. W.

    2006-12-01

    379

    ENSO effect on the sea surface wind and sea surface temperature in the Taiwan Strait  

    Microsoft Academic Search

    The ERS scatterometer and NOAA\\/AVHRR data during 1996\\/4–2000\\/12 are used to examine the variations of the sea surface wind and sea surface temperature (SST) in the Taiwan Strait (TS) through Empirical Orthogonal Function (EOF) analysis. It is found that the sea surface wind in the TS is southwesterly in summer but northeasterly in the other seasons. Meanwhile, the sea surface

    Nan-Jung Kuo; Chung-Ru Ho

    2004-01-01

    380

    ENSO effect on the sea surface wind and sea surface temperature in the Taiwan Strait  

    Microsoft Academic Search

    The ERS scatterometer and NOAA\\/AVHRR data during 1996\\/4-2000\\/12 are used to examine the variations of the sea surface wind and sea surface temperature (SST) in the Taiwan Strait (TS) through Empirical Orthogonal Function (EOF) analysis. It is found that the sea surface wind in the TS is southwesterly in summer but northeasterly in the other seasons. Meanwhile, the sea surface

    Nan-Jung Kuo; Chung-Ru Ho

    2004-01-01

    381

    EROSION OF KAPTON H BY HYPERTHERMAL ATOMIC OXYGEN: DEPENDENCE ON O-ATOM FLUENCE AND SURFACE TEMPERATURE  

    Microsoft Academic Search

    Organic polymers are susceptible to erosion from reaction with ambient atomic oxygen in low Earth orbit. We have investigated\\u000a the linearity of the O-atom fluence dependence of Kapton H erosion and the dependence of Kapton H erosion yield on surface\\u000a temperature. Sample exposures were performed with a pulsed beam containing hyperthermal O atoms that were generated with a\\u000a laser detonation

    DEANNA M. BUCZALA; TIMOTHY K. MINTON

    382

    Low Temperature Optical Constants of Hydrated Magnesium Sulfates For Planetary Surfaces  

    NASA Astrophysics Data System (ADS)

    Quantifying surface composition is essential to interpreting the surface features and understanding the formation, evolution, and interior processes of icy satellites from spacecraft spectrometer and imaging data. The composition of icy body surfaces can be constrained to first order by comparing to laboratory reflectance spectra obtained under appropriate conditions of temperature and pressure, and related linear (area-based) mixture modeling. More advanced quantitative determination of surface abundances via nonlinear mixing models requires optical functions or "constants” (real and imaginary indices of refraction, n(?) and k(?)). In this work, we investigate three hydrated Mg sulfates (epsomite, bloedite, hexahydrite) that are spectrally similar to observations of non-icy surface deposits on outer Solar System icy satellites and Mars. These compounds are particularly important because they have aqueous chemistry consistent with that predicted for subsurface oceans and paleolake basins on Europa, Ganymede, Enceladus, and Mars and may be useful indicators of astrobiological potential. We present n(?) and k(?), derived from laboratory reflectance spectra (Dalton et al., 2005, Icarus 177, 472) acquired at visible to near-infrared wavelengths, for epsomite, bloedite, and hexahydrite at both 300 K (valid for Earth and Mars equatorial regions) and 120 K (optimized for Europa's dayside temperature). Applications of these cryogenic n(?), k(?) data to radiative transfer models of telescopic observations of icy worlds and mission data (Galileo NIMS, Cassini VIMS, and New Horizons LEISA) will be discussed. This work is supported through the NASA Outer Planets Research Program.

    Pitman, Karly M.; Dalton, J. B., III

    2010-10-01

    383

    Thermostable DNA Immobilization and Temperature Effects on Surface Hybridization  

    PubMed Central

    Monolayer films of nucleic acids on solid supports are encountered in a range of diagnostic and bioanalytical applications. These applications often rely on elevated temperatures to improve performance; moreover, studies at elevated temperatures can provide fundamental information on layer organization and functionality. To support such applications, this study compares thermostability of oligonucleotide monolayers immobilized to gold by first coating the gold with a nanometer-thick film (an “anchor layer”) of a polymercaptosiloxane, to which DNA oligonucleotides are subsequently tethered through maleimide-thiol conjugation, with thermostability of monolayers formed via widely-used attachment through a terminal thiol moiety on the DNA. The temperature range covered is from 25 to 90 °C. After confirming stability of immobilization and, more importantly, retention of hybridization activity even under the harshest conditions investigated, these thermostable films are used to demonstrate measurements of (1) reversible surface melting transitions and (2) temperature dependence of competitive hybridization, when fully matched and mismatched sequences compete for binding to immobilized DNA oligonucleotides. The competitive hybridization experiments reveal a pronounced impact of temperature on rates of approach to equilibrium, with kinetic freezing into nonequilibrium states close to room temperature and rapid approach to equilibrium at elevated temperatures. Modeling of competitive surface hybridization equilibria using thermodynamic parameters derived from surface melting transitions of the individual sequences is also discussed.

    Ge, Dongbiao; Wang, Xin; Williams, Keeshan; Levicky, Rastislav

    2012-01-01

    384

    Comparison Of Land Surface Temperature Derived From MODIS And AVHRR Sensors  

    NASA Astrophysics Data System (ADS)

    Sensors on board several satellites can measure the thermal infrared radiation emitted from the earth's surface. By applying specific algorithms, this data can be used to produce Land Surface Temperature (LST) maps. This data is very important in energy balance studies, climate modeling and global change studies. This paper compares LST data derived from the Advanced High Resolution Radiometer (AVHRR) aboard the NOAA polar orbiting satellites and LST derived from the Moderate Resolution Imaging Spectroradiometer (MODIS) aboard the NASA Terra and Aqua satellites. The AVHRR datasets were obtained from the USGS and New Mexico State University (NMSU) and the MODIS datasets were obtained from the NASA Distributed Active Archive Center (DAAC). Data were compared for 42 sites in New Mexico. These sites represent the range of land cover and terrain typical to New Mexico. The datasets use different compositing techniques and composite periods to arrive at a cloud free dataset. The LST's were compared to each other and were also compared with air temperatures reported by meteorological stations at these locations. Air temperature from these weather stations is being used in many biological and physical studies such as estimating crop ET and for use in phenology models. However, weather stations only provide data at a single point and the accuracy of these models decrease as the distance from the station increases. By obtaining a simple relationship between LST and air temperature it may be possible to use the high spatial resolution of the LST data to estimate variation in air temperature measurements over a region.

    Atencio, J.; Sanderson, R.; Bleiweiss, M. P.; Steiner, R.

    2005-12-01

    385

    Sea Surface Temperature Trends of the Gulf Stream  

    NSDL National Science Digital Library

    One of the most studied and important ocean currents of the world lies along the eastern coast of the United States and is called the Gulf Stream. It derives its name from its source region of warm water in the Gulf of Mexico. For the past two decades, scientists have been collecting sea surface temperature (SST) data from satellites, buoys and ships in the Gulf Stream and Atlantic Basin. In this three-part lesson, students will explore the Live Access Server (LAS) and produce plots of sea surface temperature. They then prepare a time series of data for particular location(s) on the Gulf Stream and use Excel to produce and analyze graphs of sea surface temperature. The lesson provides detailed procedure, related links, sample graphs, follow-up questions, extensions, and teacher notes.

    2006-10-31

    386

    Does scandium resemble transition or rare earth metals when it is grown on silicon surfaces?  

    NASA Astrophysics Data System (ADS)

    Scandium (Sc) has long been considered a rare earth (RE) element rather than a transition metal (TM) when grown on silicon (Si) surfaces, although little experimental evidence supports it. When scandium nitride (ScN) grown on Si is a promising buffer material for combining gallium nitride (GaN) and Si, a thin Sc silicide layer may be formed at the ScN/Si interface and, therefore, the electronic properties of Sc on Si are becoming an important issue to address. In this study, the interfacial atomic and electronic properties of Sc on n-type Si (111)-7 × 7 reconstructed surfaces have been studied by low energy electron diffraction and synchrotron radiation based high-resolution X-ray photoemission spectroscopy. By varying the Sc overlayer thickness, different silicide phases were observed and the Schottky barrier (SB) evolution was obtained. The SB evolution of Sc on Si is closer to TM than RE. This barrier may interfere with carrier transportation if GaN/ScN/Si tri-layered heterostructures are grown.

    Shiu, H. W.; Chang, L. Y.; Lou, J. L.; Wu, C. P.; Chen, C.-H.

    2013-01-01

    387

    Locally adaptive template sizes for matching repeat images of Earth surface mass movements  

    NASA Astrophysics Data System (ADS)

    This paper presents an algorithm for locally adaptive template sizes in normalized cross-correlation (NCC) based image matching for measuring horizontal surface displacements of mass movements. After adaptively identifying candidate templates based on the image signal-to-noise ratio (SNR), the algorithm iteratively looks for the size at which the maximum cross-correlation coefficient attains a local peak and the matching position gets fixed. The algorithm is tested on modeled (deformed) images and applied to real bi-temporal images of different Earth surface mass movements. It is evaluated in comparison with globally (image-wide) fixed template sizes ranging from 11 to 101 pixels based on the improvement in the accuracy of displacement estimation and the SNR of image reconstruction. The results show that the algorithm could reduce the error of displacement estimation by up to over 90% (in the modeled case) and improve the SNR of the matching by up to over four times compared to the globally fixed template sizes highly reducing the effects of geometric distortion and noise. The algorithm pushes terrain displacement measurement from repeat images one step forward towards full automation.

    Debella-Gilo, Misganu; Kääb, Andreas

    2012-04-01

    388

    Global Temperature Time Series  

    NSDL National Science Digital Library

    The phenomenon is the rising and falling of temperatures on the Earth's surface. Click to choose a city on a regional map, showing graphs of the daily maximum, minimum, and mean temperatures for a 365 day time period.

    389

    Uncertainty in the velocity between the mass center and surface of Earth  

    NASA Astrophysics Data System (ADS)

    Using spectral analysis and data decimation, we estimate the uncertainty in the velocity between the cumulative mass center of Earth (CM) and geodetic sites on Earth's surface. Knowing this velocity is crucial for evaluating space geodetic observations of continental uplift and subsidence in terms of postglacial rebound and sea level rise. We find SLR observations of satellite LAGEOS to constrain the X and Y components of the velocity of CM to ±0.4 mm/yr and the Z component to ±0.9 mm/yr. (95% confidence limits, X is in the direction of 0°N 0°E, Y of 0°N 90°E, and Z of 90°N.) The uncertainty in Z is high, so that the estimate includes the independent inference made jointly using site velocities, the rigid plate hypothesis, and models of postglacial rebound that the true velocity of CM has a Z component of 0.5-1.0 mm/yr relative to that in ITRF2008. Uncertainty in scale rate, an intermediate parameter in the determination of an ITRF, is ±0.36 mm/yr for VLBI, ±0.52 mm/yr for SLR, and ±0.20 mm/yr for GPS. The scale of GPS depends on that of VLBI and SLR, but the low GPS uncertainty indicates that GPS results are, for the first time, unbiased by changing satellite Block types, evidently due to newly incorporated satellite phase center variations. GPS constrains the velocity of CM nearly as well as SLR, representing a technical advance given that a GPS satellite is not a sphere and responds strongly to solar radiation pressure.

    Argus, Donald F.

    2012-10-01

    390

    Annual Global Surface Temperature Anomaly: 1950 through 1998  

    NSDL National Science Digital Library

    Global surface temperatures in 1998 set a new record for the period of instrumental measurements, report researchers at the NASA Goddard Institute for Space Studies who analyze data collected from several thousand meteorological stations around the world. This visualization shows surface temperature anomalies from 1950 through November, 1998. The 1998 warmth was associated partly with a strong El Nino that warmed the air over the eastern tropical Pacific Ocean in the first half of the year and in turn affected weather around the world. Red and yellow colors indicate warmer than normal conditions and blue colors indicates cooler than normal conditions.

    Allen, Jesse; Hansen, James

    1998-11-01

    391

    Annual North America Surface Temperature Anomaly: 1950 through 1998  

    NSDL National Science Digital Library

    Global surface temperatures in 1998 set a new record for the period of instrumental measurements, report researchers at the NASA Goddard Institute for Space Studies who analyze data collected from several thousand meteorological stations around the world. This visualization shows surface temperature anomalies from 1950 through November, 1998. The 1998 warmth was associated partly with a strong El Nino that warmed the air over the eastern tropical Pacific Ocean in the first half of the year and in turn affected weather around the world. Red and yellow colors indicate warmer than normal conditions and blue colors indicates cooler than normal conditions.

    Allen, Jesse; Hansen, James

    1998-11-01

    392

    The role of land surface dynamics in glacial inception: a study with the UVic Earth System Model  

    Microsoft Academic Search

    The first results of the UVic Earth System Model coupled to a land surface scheme and a dynamic global vegetation model are presented in this study. In the first part the present day climate simulation is discussed and compared to observations. We then compare a simulation of an ice age inception (forced with 116 ka BP orbital parameters and an atmospheric CO

    K. J. Meissner; A. J. Weaver; H. D. Matthews; P. M. Cox

    2003-01-01

    393

    Seasonal variations of the Earth's gravitational field: An analysis of atmospheric pressure, ocean tidal, and surface water excitation  

    Microsoft Academic Search

    Monthly mean gravitational field parameters (denoted here as Ceven) that represent linear combinations of the primarily even-degree zonal spherical harmonic coefficients of the Earth's gravitational field have been recovered using LAGEOS I data and are compared with those derived from gridded global surface pressure data of the National Meteorological Center (NMC) spanning 1984–1992. The effect of equilibrium ocean tides and

    D. Dong; R. S. Gross; J. O. Dickey

    1996-01-01

    394

    Seasonal variations of the Earth's gravitational field: An analysis of atmospheric pressure, ocean tidal, and surface water excitation  

    Microsoft Academic Search

    Monthly mean gravitational field parameters (denoted here as Ceven) that represent linear combinations of the primarily even-degree zonal spherical harmonic coefficients of the Earth's gravitational field have been recovered using LAGEOS I data and are compared with those derived from gridded global surface pressure data of the National Meteorological Center (NMC) spanning 1984-1992. The effect of equilibrium ocean tides and

    D. Dong; R. S. Gross; J. O. Dickey

    1996-01-01

    395

    Characterization of global positioning system earth surface multipath and cross correlation for aircraft precision approach operations using software radio technology  

    NASA Astrophysics Data System (ADS)

    A GPS Software Defined Radio (SDR) is designed for the analysis of GPS error sources, and is applied to evaluate earth-surface multipath errors and self-interference errors due to C/A code cross correlation for aircraft precision approach operations. The pseudorange error caused by earth-surface multipath is characterized for airborne GPS receivers. A detection algorithm that can estimate the strength of earth-surface multipath from the received signals is developed and implemented in the GPS SDR. The response to earth-surface multipath from different GPS receiver architectures is studied, from which it is determined that the pseudorange errors could be bounded to within a few decimeters with a careful selection of tracking algorithms. GPS self-interference caused by C/A code cross correlation is evaluated in the operational environment. The induced errors on pseudorange and Carrier to Noise Ratio estimation are characterized, and bounds are determined for relative signal strength, Doppler frequency, and Doppler change rate to limit the pseudorange errors to 0.2 m.

    Zhu, Zhen

    396

    The Correction of Great Circular Surface Wave Phase Velocity Measurements for the Rotation and Ellipticity of the Earth  

    Microsoft Academic Search

    Normal mode perturbation theory is combined with a geometrical optics approximation in order to establish a procedure for correcting great circular Love and Rayleigh surface wave phase velocity measurements for the effects of the rotation and the hydrostatic ellipsoidal shape of the earth. The necessary correction can be made by utilizing in the measurement process an apparent path length Lapp(T,

    F. A. Dahlen

    1975-01-01

    397

    Modeling the Global Solar Radiation on the Earth's Surface Using Atmospheric Deterministic and Intelligent Data-Driven Techniques  

    Microsoft Academic Search

    Three methods for analyzing and modeling the global shortwave radiation reaching the earth's surface are presented in this study. Solar radiation is a very important input for many aspects of climatology, hydrology, atmospheric sciences, and energy applications. The estimation methods consist of an atmospheric deterministic model and two data-driven intelligent methods.The deterministic method is a broadband atmospheric model, developed for

    M. Santamouris; G. Mihalakakou; B. Psiloglou; G. Eftaxias; D. N. Asimakopoulos

    1999-01-01

    398

    Amplification of surface temperature trends and variability in the tropical atmosphere.  

    PubMed

    The month-to-month variability of tropical temperatures is larger in the troposphere than at Earth's surface. This amplification behavior is similar in a range of observations and climate model simulations and is consistent with basic theory. On multidecadal time scales, tropospheric amplification of surface warming is a robust feature of model simulations, but it occurs in only one observational data set. Other observations show weak, or even negative, amplification. These results suggest either that different physical mechanisms control amplification processes on monthly and decadal time scales, and models fail to capture such behavior; or (more plausibly) that residual errors in several observational data sets used here affect their representation of long-term trends. PMID:16099951

    Santer, B D; Wigley, T M L; Mears, C; Wentz, F J; Klein, S A; Seidel, D J; Taylor, K E; Thorne, P W; Wehner, M F; Gleckler, P J; Boyle, J S; Collins, W D; Dixon, K W; Doutriaux, C; Free, M; Fu, Q; Hansen, J E; Jones, G S; Ruedy, R; Karl, T R; Lanzante, J R; Meehl, G A; Ramaswamy, V; Russell, G; Schmidt, G A

    2005-08-11

    399

    Amplification of Surface Temperature Trends and Variability in the Tropical Atmosphere  

    NASA Astrophysics Data System (ADS)

    The month-to-month variability of tropical temperatures is larger in the troposphere than at Earth's surface. This amplification behavior is similar in a range of observations and climate model simulations and is consistent with basic theory. On multidecadal time scales, tropospheric amplification of surface warming is a robust feature of model simulations, but it occurs in only one observational data set. Other observations show weak, or even negative, amplification. These results suggest either that different physical mechanisms control amplification processes on monthly and decadal time scales, and models fail to capture such behavior; or (more plausibly) that residual errors in several observational data sets used here affect their representation of long-term trends.

    Santer, B. D.; Wigley, T. M. L.; Mears, C.; Wentz, F. J.; Klein, S. A.; Seidel, D. J.; Taylor, K. E.; Thorne, P. W.; Wehner, M. F.; Gleckler, P. J.; Boyle, J. S.; Collins, W. D.; Dixon, K. W.; Doutriaux, C.; Free, M.; Fu, Q.; Hansen, J. E.; Jones, G. S.; Ruedy, R.; Karl, T. R.; Lanzante, J. R.; Meehl, G. A.; Ramaswamy, V.; Russell, G.; Schmidt, G. A.

    2005-09-01

    400

    Design, microstructure, and high-temperature behavior of silicon nitride sintered with rate-earth oxides  

    SciTech Connect

    The processing-microstructure-property relations of silicon nitride ceramics sintered with rare-earth oxide additives have been investigated with the aim of improving their high-temperature behavior. The additions of the oxides of Y, Sm, Gd, Dy, Er, or Yb were compositionally controlled to tailor the intergranular phase. The resulting microstructure consisted of {beta}-Si{sub 3}N{sub 4} grains and a crystalline secondary phase of RE{sub 2}Si{sub 2}O{sub 7}, with a thin residual amorphous phase present at grain boundaries. The lanthanide oxides were found to be as effective as Y{sub 2}O{sub 3} in densifying Si{sub 3}N{sub 4}, resulting in identical microstructures. The crystallization behavior of all six disilicates was similar, characterized by a limited nucleation and rapid growth mechanism resulting in large single crystals. Complete crystallization of the intergranular phase was obtained with the exception of a residual amorphous, observed at interfaces and believed to be rich in impurities, the cause of incomplete devitrification. The low resistance to oxidation of these materials was attributed to the minimization of amorphous phases via devitrification to disilicates, compatible with SiO{sub 2}, the oxidation product of Si{sub 3}N{sub 4}. The strength retention of these materials at 1300{degrees}C was found to be between 80% and 91% of room-temperature strength, due to crystallization of the secondary phase and a residual but refractory amorphous grain-boundary phase. The creep behavior was found to be strongly dependent on residual amorphous phase viscosity as well as on the oxidation behavior, as evidenced by the nonsteady-state creep rates of all materials. 122 refs., 51 figs., 12 tabs.

    Ciniculk, M.K. (California Univ., Berkeley, CA (United States). Dept. of Materials Science and Mineral Engineering)

    1991-08-01

    401

    Diurnal Variations of Titan's Surface Temperatures From Cassini -CIRS Observations  

    NASA Astrophysics Data System (ADS)

    The Cassini Composite Infrared Spectrometer (CIRS) observations of Saturn's largest moon, Titan, are providing us with the ability to detect the surface temperature of the planet by studying its outgoing radiance through a spectral window in the thermal infrared at 19 m (530 cm-1) characterized by low opacity. Since the first acquisitions of CIRS Titan data the in-strument has gathered a large amount of spectra covering a wide range of latitudes, longitudes and local times. We retrieve the surface temperature and the atmospheric temperature pro-file by modeling proper zonally averaged spectra of nadir observations with radiative transfer computations. Our forward model uses the correlated-k approximation for spectral opacity to calculate the emitted radiance, including contributions from collision induced pairs of CH4, N2 and H2, haze, and gaseous emission lines (Irwin et al. 2008). The retrieval method uses a non-linear least-squares optimal estimation technique to iteratively adjust the model parameters to achieve a spectral fit (Rodgers 2000). We show an accurate selection of the wide amount of data available in terms of footprint diameter on the planet and observational conditions, together with the retrieved results. Our results represent formal retrievals of surface brightness temperatures from the Cassini CIRS dataset using a full radiative transfer treatment, and we compare to the earlier findings of Jennings et al. (2009). The application of our methodology over wide areas has increased the planet coverage and accuracy of our knowledge of Titan's surface brightness temperature. In particular we had the chance to look for diurnal variations in surface temperature around the equator: a trend with slowly increasing temperature toward the late afternoon reveals that diurnal temperature changes are present on Titan surface. References: Irwin, P.G.J., et al.: "The NEMESIS planetary atmosphere radiative transfer and retrieval tool" (2008). JQSRT, Vol. 109, pp. 1136-1150, 2008. Rodgers, C. D.: "Inverse Methods For Atmospheric Sounding: Theory and Practice". World Scientific, Singapore, 2000. Jennings, D.E., et al.: "Titan's Surface Brightness Temperatures." Ap. J. L., Vol. 691, pp. L103-L105, 2009.

    Cottini, Valeria; Nixon, Conor; Jennings, Don; Anderson, Carrie; Samuelson, Robert; Irwin, Patrick; Flasar, F. Michael

    402

    Solitary ionizing surface waves on low-temperature plasmas  

    Microsoft Academic Search

    A simple model for studying finite-amplitude ionizing nonlinear surface waves propagating in a partially ionized low-temperature plasma, in which collisional effects such as ionization, recombination, and friction are dominant, is proposed. The authors consider the lowest order namely, second order in the fields) nonlinear problem and investigate the evolution of finite-amplitude electromagnetic surface waves. It is shown that the waves

    Sergey V. Vladimirov; Ming Y. Yu

    1993-01-01

    403

    On the influence of North Pacific sea surface temperature on the Arctic winter climate  

    NASA Astrophysics Data System (ADS)

    Differences between two ensembles of Goddard Earth Observing System Chemistry-Climate Model simulations isolate the impact of North Pacific sea surface temperatures (SSTs) on the Arctic winter climate. One ensemble of extended winter season forecasts is forced by unusually high SSTs in the North Pacific, while in the second ensemble SSTs in the North Pacific are unusually low. High - Low differences are consistent with a strengthened Western Pacific atmospheric teleconnection pattern, and in particular, a weakening of the Aleutian low. This relative change in tropospheric circulation inhibits planetary wave propagation into the stratosphere, in turn reducing polar stratospheric temperature in mid- and late winter. The number of winters with sudden stratospheric warmings is approximately tripled in the Low ensemble as compared with the High ensemble. Enhanced North Pacific SSTs, and thus a more stable and persistent Arctic vortex, lead to a relative decrease in lower stratospheric ozone in spring, affecting the April clear-sky UV index at Northern Hemisphere midlatitudes.

    Hurwitz, M. M.; Newman, P. A.; Garfinkel, C. I.

    2012-10-01

    404

    Spatial correlations of interdecadal variation in global surface temperatures  

    Microsoft Academic Search

    We have analyzed spatial correlation patterns of interdecadal global surface temperature variability from an empirical perspective. Using multi-taper coherence estimates from 140-yr records, we find that correlations between hemispheres are significant at ?95% confidence for non-randomness for most of the frequency band 0.06 temperature data series near 5-yr period reveal

    Michael E. Mann; Jeffrey Park

    1993-01-01

    405

    Surface temperature and spectral measurements at Santiaguito lava dome, Guatemala  

    Microsoft Academic Search

    An infrared thermometer, spectroradiometer and digital video camera were used to observe and document short-term evolution of surface brightness temperature and morphology at Santiaguito lava dome, Guatemala. The thermometer dataset shows 40-70 minute-long cooling cycles, each defined by a cooling curve that is both initiated and terminated by rapid increases in temperature due to regular ash venting. The average cooling

    Steve T. M. Sahetapy-Engel; Luke P. Flynn; Andrew J. L. Harris; Gregg J. Bluth; William I. Rose; Otoniel Matias

    2004-01-01

    406

    Surface temperature and spectral measurements at Santiaguito lava dome, Guatemala  

    Microsoft Academic Search

    An infrared thermometer, spectroradiometer and digital video camera were used to observe and document short-term evolution of surface brightness temperature and morphology at Santiaguito lava dome, Guatemala. The thermometer dataset shows 40–70 minute-long cooling cycles, each defined by a cooling curve that is both initiated and terminated by rapid increases in temperature due to regular ash venting. The average cooling

    Steve T. M. Sahetapy-Engel; Luke P. Flynn; Andrew J. L. Harris; Gregg J. Bluth; William I. Rose; Otoniel Matias

    2004-01-01

    407

    Japanese Whaling Ships' Sea Surface Temperatures 1946-84.  

    NASA Astrophysics Data System (ADS)

    Japanese whaling ship data, a homogeneous dataset mainly covering the southern high-latitude oceans, may be used to fill in gaps in recent sea surface temperature datasets, contributing a fair number of additional observations in this area. The Japanese whaling ship data are treated separately here for the period 1946-84, and they show no significant temperature changes during this period in the main fishing region of 60°-70°S or in the west Pacific warm pool.

    Mierzejewska, Anna W.; Wu, Zhongxiang; Newell, Reginald E.; Miyashita, Tomio

    1997-03-01

    408

    Magnetic circular dichroism in photoemission from rare earth materials: a new technique in surface and thin-film magnetism  

    Microsoft Academic Search

    Using circularly polarized X-rays to excite photoelectrons from magnetically ordered rare-earth materials gives rise to large magnetic circular dichroism in photoemission (MCD-PE), i.e. the intensity of 4f-photoemission lines strongly depends on the orientation of sample magnetization with respect to the photon spin. To explore its potential for application as near-surface magnetometer with atomic-layer resolution, we studied MCD-PE at the (0001)-surfaces

    K. Starke; E. Navas; E. Arenholz; L. Baumgarten; G. Kaindl

    1995-01-01

    409

    On the Earth's surface energy exchange determination from ERS satellite ATSR data: Part 2. Short-wave radiation  

    Microsoft Academic Search

    This is the second in a series of papers which discusses determination of the Earth's surface energy exchange from ERS satellite Along-Track Scanning Radiometer (ATSR) data. The paper concentrates on short-wave radiation on sea and land surfaces. In this paper, three methods were used to determine solar irradiance by using ERS ATSR-2 data. We referred to them as 'D scheme',

    Yong Xue; D. T. Llewellyn-Jones; S. P. Lawrence; C. T. Mutlow

    2000-01-01

    410

    Road surface temperature forecast through multivariate data analysis  

    NASA Astrophysics Data System (ADS)

    Road surface temperature forecast is a key component of winter maintenance strategy in many western countries. Numerous tools exist to aid road managers in organizing services and consequently triggering de-icing operations. Forecasting strategies have been common place since the 1980s, of which thermal mapping has been long established component to get the spatial variation of road temperature along roads. The technique uses IR thermometry to measure road pavement temperature and an atmospheric probe for air temperature, both at a high resolution interval, to identify sections of the road network prone to ice occurrence. However, measurements are time-consuming and ultimately only provide a snapshot of a network at the time of the survey. As such, surveys have to be conducted under a series of specific climatic conditions during winter but it is questionable whether the range of atmospheric conditions is representative enough of winter. This work investigates the role of multivariate data analysis to thermal mapping data. Principal Components Analysis and Partial Least-square regression were used to interpolate between individual thermal mapping surveys to build a thermal map and road surface temperature forecast, for a wider range of climatic conditions. The results indicate that when this approach needed fewer thermal mapping surveys. Furthermore, comparisons with numerical models indicate the combination of multivariate data analysis and of thermal mapping as an appropriate verification method for the road surface temperature forecasts.

    Marchetti, Mario; Khalifa, Abderrhamen; Dumoulin, Jean

    2013-04-01

    411

    Low-Temperature Modification of Gallium Arsenide Surface Electronic Properties  

    NASA Astrophysics Data System (ADS)

    Exploration of new process techniques to control GaAs surface electronic properties is one of the important challenges facing GaAs process technology. High density of states invariably seen on the free GaAs surface causes the surface Fermi level to be pinned near the middle of the band gap and surface recombination of carriers to be high, both of which are detrimental to device performance and must be controlled. The conventional passivation scheme employs an AlGaAs overlayer; however, its growth by molecular beam epitaxy (MBE) and other techniques require elevated temperature (600^circC), which may pose certain problems, such as undesirable dopant redistribution, in some cases. The central idea of this thesis is to investigate new, low-temperature GaAs surface modification processes. Three GaAs surface passivation techniques are discussed in this thesis: the phosphorous pentasulfide rm P_2S_5 treatment, the octadecyl thiol treatment, and atomic hydrogenation of low-temperature (LT) MBE-grown GaAs. Both the rm P_2S_5 and octadecyl thiol techniques are chemical treatments of the GaAs surface at or near room temperature, requiring nothing more than some simple glassware. Yet, this investigation reveals that these simple techniques have considerable impact on the electronic properties of the GaAs surface and the metal -GaAs interface. For example, the dependence of Schottky barrier height on metal work function is increased by either of the treatments. It is also demonstrated that the octadecyl thiol technique produces a self-assembled monolayer on GaAs, believed to be the first of its kind on any semiconductor surface, and that Schottky barrier height is dependent on the number of carbon atoms in thiol. The third technique investigated is hydrogenation of GaAs grown at abnormally low temperature of 300^circC. This high-resistivity material of recent vintage, LT-MBE grown GaAs, has found some practical device applications, including GaAs surface passivation to reduce surface recombination. However, a mechanistic origin of some anomalous electronic properties that this material exhibit is still under dispute. Observed interaction of atomic hydrogen with LT MBE-grown GaAs in this thesis is shown to be most consistent with the defect band model, among other models proposed.

    Nakagawa, Osamu

    412

    Determination of Temperature Distribution in Wood with Variable Surface Temperature by Numerical Integration of Duhamel'S Integral.  

    National Technical Information Service (NTIS)

    A numerical method is developed to determine the temperature distribution in homogeneous semi-infinite or thick-walled solids when the temperature of one surface varies with time. A computer program is given in 'FORTRAN' language for the determination of ...

    F. Rattner E. L. Schaffer

    1967-01-01

    413

    Separating temperature and emissivity in thermal infrared multispectral scanner data: implications for recovering land surface temperatures  

    Microsoft Academic Search

    The accuracy of three techniques for recovering surface kinetic temperature from multispectral thermal infrared data acquired over land is evaluated. The three techniques are the reference channel method, the emissivity normalization method, and the alpha emissivity method. The methods used to recover the temperature of artificial radiance derived from a wide variety of materials. The results indicate that the emissivity

    Peter S. Kealy; Simon J. Hook

    1993-01-01

    414

    Comparison of MODIS-derived land surface temperatures with ground surface and air temperature measurements in continuous permafrost terrain  

    NASA Astrophysics Data System (ADS)

    Obtaining high resolution records of surface temperature from satellite sensors is important in the Arctic because meteorological stations are scarce and widely scattered in those vast and remote regions. Surface temperature is the primary climatic factor that governs the existence, spatial distribution and thermal regime of permafrost which is a major component of the terrestrial cryosphere. Land Surface (skin) Temperatures (LST) derived from the Moderate Resolution Imaging Spectroradiometer (MODIS) sensor aboard the Terra and Aqua satellite platforms provide spatial estimates of near-surface temperature values. In this study, LST values from MODIS are compared to ground-based near-surface air (Tair) and ground surface temperature (GST) measurements obtained from 2000 to 2008 at herbaceous and shrub tundra sites located in the continuous permafrost zone of Northern Québec, Nunavik, Canada, and of the North Slope of Alaska, USA. LSTs (temperatures at the surface materials-atmosphere interface) are found to be better correlated with Tair (1-3 m above the ground) than with available GST (3-5 cm below the ground surface). As Tair is most often used by the permafrost community, this study focused on this parameter. LSTs are in stronger agreement with Tair during the snow cover season than in the snow free season. Combining Aqua and Terra LST-Day and LST-Nigh acquisitions into a mean daily value provides a large number of LST observations and a better overall agreement with Tair. Comparison between mean daily LSTs and mean daily Tair, for all sites and all seasons pooled together yields a very high correlation (R = 0.97; mean difference (MD) = 1.8 °C; and standard deviation of MD (SD) = 4.0 °C). The large SD can be explained by the influence of surface heterogeneity within the MODIS 1 km2 grid cells, the presence of undetected clouds and the inherent difference between LST and Tair. Retrieved over several years, MODIS LSTs offer a great potential for monitoring surface temperature changes in high-latitude tundra regions and are a promising source of input data for integration into spatially-distributed permafrost models.

    Hachem, S.; Duguay, C. R.; Allard, M.

    2012-01-01

    415

    The Conundrum Posed by Io's Minimum Surface Temperatures  

    NASA Astrophysics Data System (ADS)

    Away from sites of active volcanism and obvious thermal anomalies lie the quiescent surfaces which have been believed to be passive with respect to Io's heat flow. These comprise about 80--90 percent of Io's surface area. Here is where the minimum surface temperatures are found, particularly at night in the polar regions. However, these surfaces are now known to be warmer than they should be if they were truly a passive geological unit. Direct observations by the Galileo PPR instrument yield minimum temperatures in the range of 90--95K everywhere on the night side [1,2]. A straight forward geological interpretation is that these surfaces are just old, and therefore, cool, lava flows that have not radiated all of their heat. This idea is further supported by the size and temperature distribution of the known thermal anomalies. A plot of log(cumulative area) versus log temperature yields temperatures in the vicinity of 95K when extrapolated to the surface area of Io. This would argue that the elevated minimum temperatures is just due to otherwise unseen, cooler, members of the same population of anomalies actually seen at much higher temperatures [3]. This all appears to be self-consistent. However, when the thermal emission from the "surfaces-between-the-anomalies" (maintained at 95K by heat flow) and the additional heat due to absorbed sunlight in the daytime are combined, the thermal emission radiated at 20 microns is far LARGER than that actually measured by ground-based telescopes [4]. Resolving this conundrum requires finding a thermophysical model for the surface that can accommodate both the ground-based photometric measurements and the PPR data. Current modeling approaches toward this end will be discussed. Of particular interest is a parametric model that can match the observed flux measurements but employs some semi-plausible geological units [5]. Using this model, we find that the "warm" polar regions of Io contribute an additional ˜0.6 W m-2 which brings our estimate for Io's total heat flow to 3 W m-2 averaged over the whole globe. References: [1] Spencer J. R. et al. (2000) Science, 288, 1198--1201. [2] Rathbun J. A. et al. (2001) EOS Trans. AGU, 82, P11A-11. [3] Matson D. L. et al. (2001) JGR, 106, 33021--33024. [4] Veeder G. J. et al. (1994) JGR, 99, 17095--17162. [5] Veeder et al., (2003) LPSC submitted. This work was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under contract to NASA.

    Matson, D.; Johnson, T.; Davies, A.; Veeder, G.; Blaney, D.

    2003-04-01

    416

    Temperature and strain-rate dependence of surface dislocation nucleation.  

    PubMed

    Dislocation nucleation is essential to the plastic deformation of small-volume crystalline solids. The free surface may act as an effective source of dislocations to initiate and sustain plastic flow, in conjunction with bulk sources. Here, we develop an atomistic modeling framework to address the probabilistic nature of surface dislocation nucleation. We show the activation volume associated with surface dislocation nucleation is characteristically in the range of 1-10b3, where b is the Burgers vector. Such small activation volume leads to sensitive temperature and strain-rate dependence of the nucleation stress, providing an upper bound to the size-strength relation in nanopillar compression experiments. PMID:18232884

    Zhu, Ting; Li, Ju; Samanta, Amit; Leach, Austin; Gall, Ken

    2008-01-15

    417

    Retrieval of land surface temperature from combined AVHRR data  

    NASA Astrophysics Data System (ADS)

    Accurate retrievals of land surface temperature (LST) from space are of high interest for studies of land surface processes. Here, an operationally applicable method to retrieve LST from NOAA/AVHRR data is proposed, which combines a split-window technique (SWT) for atmospheric correction with a Normalised Difference Vegetation Index threshold method for the retrieval of land surface emmisivity. Preliminary results of LST retrievals with this "combined method" are in good agreement with ground truth measurements for bare soil and wheat crops. The results are also compared with results from the same SWT but using emmisivities from laboratory measurements.

    Sun, Y.-Y.; Göttsche, F.-M.; Olesen, F.-S.; Fischer, H.

    2002-08-01

    418

    Unexpected and Unexplained Surface Temperature Variations on Mimas  

    NASA Astrophysics Data System (ADS)

    Until recently it was thought one of the most interesting things about Mimas, Saturn’s innermost classical icy moon, was its resemblance to Star Wars’ Death Star. However, a bizarre pattern of daytime surface temperatures was observed on Mimas using data obtained by Cassini’s Composite Infrared Spectrometer (CIRS) in February 2010. The observations were taken during Cassini’s closest ever encounter with Mimas (<10,000 km) and cover the daytime anti-Saturn hemisphere centered on longitude ~145° W. Instead of surface temperatures smoothly increasing throughout the morning and early afternoon, then cooling in the evening, as expected, a sharp V-shaped boundary is observed separating cooler midday and afternoon temperatures (~77 K) on the leading side from warmer morning temperatures (~92 K) on the trailing side. The boundary’s apex is centered at equatorial latitudes near the anti-Saturn point and extends to low north and south latitudes on the trailing side. Subtle differences in the surface colors have been observed that are roughly spatially correlated with the observed extent of the temperature anomaly, with the cooler regions tending to be bluer (Schenk et al., Submitted). However, visible-wavelength albedo is similar in the two regions, so albedo variations are probably not directly responsible for the thermal anomaly. It is more likely that thermal inertia variations produce the anomaly, with thermal inertia being unusually high in the region with anomalously low daytime temperatures. Comparison of the February 2010 CIRS data to previous lower spatial resolution data taken at different local times tentatively confirm that the cooler regions do indeed display higher thermal inertias. Bombardment of the surface by high energy electrons from Saturn’s radiation belts has been proposed to explain the observed color variations (Schenk et al., Submitted). Electrons above ~1 MeV preferentially impact Mimas’ leading hemisphere at low latitudes where they could cause surface defects. For this process to also explain the observed temperature differences it would have to affect the surface’s thermal inertia to a depth comparable to the diurnal thermal skin-depth (~0.5 cm). However, whether the formation of the giant Herschel crater (which lies in the middle of the observed portion of the cold region) contributed to the observed temperature anomaly or if electron bombardment alone is able to explain the thermal anomaly is currently unknown. Future CIRS observations should be able to map the full spatial extent of the thermal anomaly and clarify whether it is centered on (and thus likely related to) Herschel, or is centered on the trailing hemisphere and thus likely to be related to the observed color anomaly.

    Howett, C.; Spencer, J. R.; Pearl, J. C.; Hurford, T. A.; Segura, M.; Cassini Cirs Team

    2010-12-01

    419

    Temperature and field effects on reflectivity of gallium selenide surface  

    NASA Astrophysics Data System (ADS)

    Monocrystals of gallium selenide (GaSe) has recently attracted significant attention in the field of new optoelectronic devices, due to the original combination of its specific features such as nonlinear optical properties, layered structure and high-photo sensitivity. GaSe crystals show both high reflectivity and unique surface perfection, which leads to a promising candidate for next generation optical devices. We will present our experimental results of reflection spectra of such crystals for various temperatures (273°K-383°K) and applied electric field (1 V/cm - 20 V/cm). The reflection spectra were analyzed to identify the mechanism of the reflective coefficient change in GaSe as a function of wavelength, temperature and electric field. This study will identify the optimal electrical field regimes and spectral segments, where we experimentally revealed reflective properties of GaSe are suitable for creating the field regulated optical applications of decoder and depolarizer. The temperature dependence of GaSe reflectance spectrum, its temperature and applied field dependences exemplified that the processes of photon-electron inter-exchanging on the surfaces are dominated over the bulk processes in forming the reflectance properties of layered crystals. The perfectness of natural surface and their high reflective properties weren't changed in the interval of experimental temperatures. The monolayer surface of GaSe can be utilized as an easy prepared natural plane surface for new optical devices on their surface basis in their original combinations. Such devises are applicable for optical information processing systems because of the stability function and weak dependence of the function of bulk properties.

    Alhasson, Bader; Hajiyev, Yashar; Matin, Mohammad

    2008-08-01

    420

    Titan's Surface Temperatures Maps from Cassini - CIRS Observations  

    NASA Astrophysics Data System (ADS)

    The Cassini Composite Infrared Spectrometer (CIRS) observations of Saturn's largest moon, Titan, are providing us with the ability to detect the surface temperature of the planet by studying its outgoing radiance through a spectral window in the thermal infrared at 19 ?m (530 cm-1) characterized by low opacity. Since the first acquisitions of CIRS Titan data the instrument has gathered a large amount of spectra covering a wide range of latitudes, longitudes and local times. We retrieve the surface temperature and the atmospheric temperature profile by modeling proper zonally averaged spectra of nadir observations with radiative transfer computations. Our forward model uses the correlated-k approximation for spectral opacity to calculate the emitted radiance, including contributions from collision induced pairs of CH4, N2 and H2, haze, and gaseous emission lines (Irwin et al. 2008). The retrieval method uses a non-linear least-squares optimal estimation technique to iteratively adjust the model parameters to achieve a spectral fit (Rodgers 2000). We show an accurate selection of the wide amount of data available in terms of footprint diameter on the planet and observational conditions, together with the retrieved results. Our results represent formal retrievals of surface brightness temperatures from the Cassini CIRS dataset using a full radiative transfer treatment, and we compare to the earlier findings of Jennings et al. (2009). In future, application of our methodology over wide areas should greatly increase the planet coverage and accuracy of our knowledge of Titan's surface brightness temperature. References: Irwin, P.G.J., et al.: "The NEMESIS planetary atmosphere radiative transfer and retrieval tool" (2008). JQSRT, Vol. 109, pp. 1136-1150, 2008. Rodgers, C. D.: "Inverse Methods For Atmospheric Sounding: Theory and Practice". World Scientific, Singapore, 2000. Jennings, D.E., et al.: "Titan's Surface Brightness Temperatures." Ap. J. L., Vol. 691, pp. L103-L105, 2009.

    Cottini, Valeria; Nixon, C. A.; Jennings, D. E.; Anderson, C. M.; Samuelson, R. E.; Irwin, P. G. J.; Flasar, F. M.

    2009-09-01

    421

    Surface tension of liquid sup 3 He at low temperature  

    SciTech Connect

    The thermal contribution to the surface tension {sigma} of liquid {sup 3}He due to the single quasiparticle motion is estimated in the low-T regime using a local approximation for the entropy. The density and temperature dependence of the effective mass is shown to play a crucial role in determining the behavior of {sigma}(T). The theoretical predictions explain the anomalous behavior of {sigma}(T) recently observed at low temperature by Suzuki et al. Predictions for the temperature dependence of the interfacial tension of liquid {sup 3}He-{sup 4}He mixtures are also given.

    Dalfovo, F.; Stringari, S. (Universita di Trento, Povo (Italy))

    1989-12-01

    422

    The role of liquid water in maintaining plate tectonics and the regulation of surface temperature  

    NASA Astrophysics Data System (ADS)

    Water plays an important role in mantle convection. In the ductile creep regime, the viscosity of wet rocks is weaker than the viscosity of dry rocks by several orders of magnitude. In the brittle regime, the most substantial effect is probably serpentinization which can reduce the friction coefficient by a factor of 2 or more. The difference between the strength of a wet lithosphere and that of a dry lithosphere seems to be big enough to control the very existence of plate tectonics. Because of dehydration due to partial melting the oceanic lithosphere is expected to be essentially dry above some critical depth, around 60-80 km. This would make the lithosphere strong enough to prevent plate motion. Percolation of water from the surface can be the main mechanism supplying water to the upper parts of the lithosphere. This implies that liquid water can be crucial for maintaining plate tectonics. On the other hand, the surface temperature is above the freezing point because of the greenhouse gases such as carbon dioxide. A simple model shows that if the blackbody temperature of the Earth is slightly below the freezing point of water, the feedback between plate tectonics, volcanism, and water and carbon cycles can result in an equilibrium state in which the surface temperature is established within the stability field of liquid water.

    Solomatov, V. S.

    2001-12-01

    423

    Assessing confidence in Pliocene sea surface temperatures to evaluate predictive models  

    NASA Astrophysics Data System (ADS)

    In light of mounting empirical evidence that planetary warming is well underway, the climate research community looks to palaeoclimate research for a ground-truthing measure with which to test the accuracy of future climate simulations. Model experiments that attempt to simulate climates of the past serve to identify both similarities and differences between two climate states and, when compared with simulations run by other models and with geological data, to identify model-specific biases. Uncertainties associated with both the data and the models must be considered in such an exercise. The most recent period of sustained global warmth similar to what is projected for the near future occurred about 3.3-3.0 million years ago, during the Pliocene epoch. Here, we present Pliocene sea surface temperature data, newly characterized in terms of level of confidence, along with initial experimental results from four climate models. We conclude that, in terms of sea surface temperature, models are in good agreement with estimates of Pliocene sea surface temperature in most regions except the North Atlantic. Our analysis indicates that the discrepancy between the Pliocene proxy data and model simulations in the mid-latitudes of the North Atlantic, where models underestimate warming shown by our highest-confidence data, may provide a new perspective and insight into the predictive abilities of these models in simulating a past warm interval in Earth history. This is important because the Pliocene has a number of parallels to present predictions of late twenty-first century climate.

    Dowsett, Harry J.; Robinson, Marci M.; Haywood, Alan M.; Hill, Daniel J.; Dolan, Aisling M.; Stoll, Danielle K.; Chan, Wing-Le; Abe-Ouchi, Ayako; Chandler, Mark A.; Rosenbloom, Nan A.; Otto-Bliesner, Bette L.; Bragg, Fran J.; Lunt, Daniel J.; Foley, Kevin M.; Riesselman, Christina R.

    2012-05-01

    424

    Assessing confidence in Pliocene sea surface temperatures to evaluate predictive models  

    USGS Publications Warehouse

    In light of mounting empirical evidence that planetary warming is well underway, the climate research community looks to palaeoclimate research for a ground-truthing measure with which to test the accuracy of future climate simulations. Model experiments that attempt to simulate climates of the past serve to identify both similarities and differences between two climate states and, when compared with simulations run by other models and with geological data, to identify model-specific biases. Uncertainties associated with both the data and the models must be considered in such an exercise. The most recent period of sustained global warmth similar to what is projected for the near future occurred about 3.3–3.0 million years ago, during the Pliocene epoch. Here, we present Pliocene sea surface temperature data, newly characterized in terms of level of confidence, along with initial experimental results from four climate models. We conclude that, in terms of sea surface temperature, models are in good agreement with estimates of Pliocene sea surface temperature in most regions except the North Atlantic. Our analysis indicates that the discrepancy between the Pliocene proxy data and model simulations in the mid-latitudes of the North Atlantic, where models underestimate warming shown by our highest-confidence data, may provide a new perspective and insight into the predictive abilities of these models in simulating a past warm interval in Earth history. This is important because the Pliocene has a number of parallels to present predictions of late twenty-first century climate.

    Dowsett, Harry J.; Robinson, Marci M.; Haywood, Alan M.; Hill, Daniel J.; Dolan, Aisling M.; Stoll, Danielle K.; Chan, Wing-Le; Abe-Ouchi, Ayako; Chandler, Mark A.; Rosenbloom, Nan A.; Otto-Bliesner, Bette L.; Bragg, Fran J.; Lunt, Daniel J.; Foley, Kevin M.; Riesselman, Christina R.

    2012-01-01

    425

    Effect of deep convection on the regulation of tropical sea surface temperature  

    NASA Astrophysics Data System (ADS)

    THE distribution of tropical sea surface temperatures (SSTs) is negatively skewed: a 'warm pool' with SSTs greater than 300.5 K covers roughly half the tropical oceans (15° N to 15° S), whereas SSTs as low as 293 K are observed in regions of equatorial and coastal upwelling and persistent stratus cloud cover1. SSTs are thus within 2-3 K of the highest values over a large area of the tropical ocean, leading some authors to suggest that some physical process may act to limit SSTs to below about 303 K. Ramanathan and Collins2 have proposed a 'thermostat' mechanism in which ocean warming produces enhanced deep convection, leading to the formation of extensive cirrus cloud canopies which shield the troposphere and ocean surface from incoming solar radiation. Here I suggest that a mechanism of this sort may not be required to explain the SST distribution. I argue that large-scale dynamical processes will act to maintain uniform tropical tropospheric temperatures to within about 2 K, and that, in the absence of horizontal temperature contrasts in the atmosphere, a negatively skewed SST frequency distribution is bound to develop through equilibration between the atmosphere and spatially varying SSTs. In addition, although cirrus clouds reduce the solar insolation at the Earth's surface in regions of deep convection, they would not necessarily prevent SSTs from exceeding 305 K in the face of extensive greenhouse warming.

    Wallace, John M.

    1992-05-01

    426

    Sea surface temperature cooling mode in the Pacific cold tongue  

    NASA Astrophysics Data System (ADS)

    Long-term variability in sea surface temperature (SST) in the equatorial Pacific and its relationship with global warming were investigated using three SST data sets (Hadley Center Global Sea Ice and Sea Surface Temperature, extended reconstruction sea surface temperature, and Kaplan), atmospheric fields from National Centers for Environmental Prediction/National Center for Atmospheric Research reanalysis, and subsurface sea temperature from the Simple Ocean Data Assimilation data set. A cooling mode in the equatorial Pacific cold tongue is evident in all three SST data sets for two periods: 1870-2007 and 1948-2007. This cooling, which is indicated by the second empirical orthogonal function mode, is characterized by cooling in the Pacific cold tongue and warming elsewhere in the tropical Pacific. Its principal component time series is highly correlated with global mean surface temperature combining air temperature and SST. In association with the SST cooling mode, atmospheric fields and subsurface sea temperature are coupled in the tropical Pacific during recent decades. Moreover, for the coupled models in the 20th century run (20C3M), obtained from the Intergovernmental Panel on Climate Change Fourth Assessment Report database, those with realistic features of El Niño-Southern Oscillation (ENSO) events can well show the cooling mode. However, the cooling mode is not shown in these coupled models in a preindustrial scenario with no forcing attributed to global warming. Results from observations and models suggest that the cooling mode is very likely caused by global warming. This conclusion is supported by a hypothesis that considers dynamic effects in the equatorial Pacific Ocean in response to global warming.

    Zhang, Wenjun; Li, Jianping; Zhao, Xia

    2010-12-01

    427

    Putting Technology to Work in Science - How to Select Unmanned Aerial Vehicles (UAV) and their Instrumentation for Atmospheric and Earth Surface Observations  

    Microsoft Academic Search

    The Autonomous Flying Platforms for Atmospheric and Earth Surface Observations project (APAESO) of the Energy, Environment and Water Research Center (EEWRC) at the Cyprus Institute is aimed at the dual purpose of carrying out atmospheric and earth-surface observations in the Mediterranean. The APAESO platforms will offer the unique potential to determine physical, chemical and radiative atmospheric properties, aerosol and dust

    Amit Teller; Manfred Lange; Stelios Ioannou; Christos Keleshis

    2010-01-01

    428

    Estimating Coseismic Slip and Crustal Stress Changes from Surface Displacement Data and Elastically Layered Earth Models: Findings from the 1999 Izmit, Turkey Earthquake  

    Microsoft Academic Search

    Techniques for estimating coseismic slip from surface displacement data commonly require the assumption that the Earth is elastically uniform. Neglecting the Earth's layered elastic structure in such slip inversions can cause modelers to significantly underestimate earthquake slip at depth (e.g., Savage, 1987; Hearn, 2001). That is, surface deformation from a hypothetical earthquake in a uniform elastic halfspace can be reproduced

    E. H. Hearn; R. Burgmann

    2001-01-01

    429

    Surface temperature measurements of heterogeneous explosives by IR emission  

    SciTech Connect

    The authors present measurements of the integrated IR emission (1--5 {micro}m) from both the heterogeneous explosive PBX 9501 and pure HMX at calibrated temperatures from 300 C to 2,500 C. The IR power emitted as a function of temperature is that expected of a black body, attenuated by a unique temperature independent constant which the authors report as the thermal emissivity. The authors have utilized this calibration of IR emission in measurements of the surface temperature from PBX 9501 subject to 1 GPa, two dimensional impact, and spontaneous ignition in unconfined cookoff. They demonstrate that the measurement of IR emission in this spectral region provides a temperature probe of sufficient sensitivity to resolve the thermal response from the solid explosive throughout the range of weak mechanical perturbation, prolonged heating to ignition, and combustion.

    Henson, B.F.; Funk, D.J.; Dickson, P.M.; Fugard, C.S.; Asay, B.W.

    1998-03-01

    430

    Room temperature wafer direct bonding of smooth Si surfaces recovered by Ne beam surface treatments  

    NASA Astrophysics Data System (ADS)

    We examined the applicability of a Ne fast atom beam (FAB) to surface activated bonding of Si wafers at room temperature. With etching depth more than 1.5 nm, the bonding strength comparable to Si bulk strength was attained. Moreover, we found the improvement of the bonding strength by surface smoothing effect of the Ne FAB. Silicon surface roughness decreased from 0.40 to 0.17 nm rms by applying a Ne FAB of 30 nm etching depth. The bonding strength between surfaces recovered by Ne FAB surface smoothing was largely improved and finally became equivalent to Si bulk strength.

    Kurashima, Yuichi; Maeda, Atsuhiko; Takagi, Hideki

    2013-06-01