Sample records for surface weather observations

  1. Evaluation of Two Ultrasonic Snow Depth Sensors for National Weather Service Automated Surface Observation System Sites

    Microsoft Academic Search

    W. A. Brazenec; N. J. Doesken; S. R. Fassnacht

    2004-01-01

    In the late 1980's the National Weather Service (NWS) deployed the Automated Surface Observing System (ASOS) at airport observing sites, eliminating the need for human observers. At the time there were no reliable sensors to measure snow depth and the traditional snow measurements of 6 hour snowfall and snow water equivalent (SWE) were abandoned at most locations. The National Weather

  2. On Observing the Weather

    NSDL National Science Digital Library

    Peter Crane

    2004-05-01

    In this article, Mount Washington Observatory meteorologist Tim Markle shares the ins and outs of his daily weather-observing routine and offers insights on making weather observations at home or at school.

  3. Weather Observing Fundamentals

    NSDL National Science Digital Library

    COMET

    2014-03-11

    "Weather Observing Fundamentals" provides guidance for U.S. Navy Aerographer's Mates, Quartermasters, and civilian observers tasked with taking and reporting routine, special, and synoptic observations. Although the focus of this lesson is on shipboard observations, much of the content applies to land-based observing and reporting as well. The lesson details standard procedures for taking accurate weather observations and for encoding those observations on COMNAVMETOCCOM Report 3141/3. Exercises throughout the lesson and four weather identification drills at the end provide learners with opportunities to practice and build their skills. The lesson covers a large amount of content. You may wish to work through the material in multiple sessions.

  4. Optimizing weather radar observations using an adaptive multiquadric surface fitting algorithm

    NASA Astrophysics Data System (ADS)

    Martens, Brecht; Cabus, Pieter; De Jongh, Inge; Verhoest, Niko

    2013-04-01

    Real time forecasting of river flow is an essential tool in operational water management. Such real time modelling systems require well calibrated models which can make use of spatially distributed rainfall observations. Weather radars provide spatial data, however, since radar measurements are sensitive to a large range of error sources, often a discrepancy between radar observations and ground-based measurements, which are mostly considered as ground truth, can be observed. Through merging ground observations with the radar product, often referred to as data merging, one may force the radar observations to better correspond to the ground-based measurements, without losing the spatial information. In this paper, radar images and ground-based measurements of rainfall are merged based on interpolated gauge-adjustment factors (Moore et al., 1998; Cole and Moore, 2008) or scaling factors. Using the following equation, scaling factors (C(x?)) are calculated at each position x? where a gauge measurement (Ig(x?)) is available: Ig(x?)+-? C (x?) = Ir(x?)+ ? (1) where Ir(x?) is the radar-based observation in the pixel overlapping the rain gauge and ? is a constant making sure the scaling factor can be calculated when Ir(x?) is zero. These scaling factors are interpolated on the radar grid, resulting in a unique scaling factor for each pixel. Multiquadric surface fitting is used as an interpolation algorithm (Hardy, 1971): C*(x0) = aTv + a0 (2) where C*(x0) is the prediction at location x0, the vector a (Nx1, with N the number of ground-based measurements used) and the constant a0 parameters describing the surface and v an Nx1 vector containing the (Euclidian) distance between each point x? used in the interpolation and the point x0. The parameters describing the surface are derived by forcing the surface to be an exact interpolator and impose that the sum of the parameters in a should be zero. However, often, the surface is allowed to pass near the observations (i.e. the observed scaling factors C(x?)) on a distance a?K by introducing an offset parameter K, which results in slightly different equations to calculate a and a0. The described technique is currently being used by the Flemish Environmental Agency in an online forecasting system of river discharges within Flanders (Belgium). However, rescaling the radar data using the described algorithm is not always giving rise to an improved weather radar product. Probably one of the main reasons is the parameters K and ? which are implemented as constants. It can be expected that, among others, depending on the characteristics of the rainfall, different values for the parameters should be used. Adaptation of the parameter values is achieved by an online calibration of K and ? at each time step (every 15 minutes), using validated rain gauge measurements as ground truth. Results demonstrate that rescaling radar images using optimized values for K and ? at each time step lead to a significant improvement of the rainfall estimation, which in turn will result in higher quality discharge predictions. Moreover, it is shown that calibrated values for K and ? can be obtained in near-real time. References Cole, S. J., and Moore, R. J. (2008). Hydrological modelling using raingauge- and radar-based estimators of areal rainfall. Journal of Hydrology, 358(3-4), 159-181. Hardy, R.L., (1971) Multiquadric equations of topography and other irregular surfaces, Journal of Geophysical Research, 76(8): 1905-1915. Moore, R. J., Watson, B. C., Jones, D. A. and Black, K. B. (1989). London weather radar local calibration study. Technical report, Institute of Hydrology.

  5. Space Weathering of Asteroid Surfaces

    NASA Astrophysics Data System (ADS)

    Chapman, Clark R.

    2004-05-01

    Visible and near-infrared spectra of reflected sunlight from asteroid surfaces exhibit features that hold the promise for identifying surface mineralogy. However, the very surfaces that are observed by remote-sensing are also subject to impingement by micrometeoroids and solar wind particles, which are believed to play the dominant role in space weathering, which is the time-dependent modification of an asteroid's reflectance spectrum. Such space weathering has confused the interpretations of telescopic spectra of asteroids, especially concerning the possible association of common ordinary chondritic meteorites with so-called S-type asteroids. Recent spacecraft studies of asteroids (especially of Eros by NEAR-Shoemaker) have documented aspects of space weathering processes, but we still do not understand the physics of space weathering well enough to confidently assay mineralogy of diverse asteroids by remote-sensing. A review of the intellectual history of this topic reveals the complexity of interdisciplinary research on far-away astronomical bodies.

  6. Weather and climate. [review of satellite observations

    NASA Technical Reports Server (NTRS)

    Atlas, D.

    1981-01-01

    Highlights of recent progress and the directions of future advances in the application of space observations to weather and climate are reviewed. In mesometeorology and severe storms, satellite stereography of cloud topography and temperature profiling from GOES-VAS promise dramatic developments in both nowcasting and prediction. In global weather, the initial results from the year long Global Weather Experiment conclusively demonstrate the enhanced forecast skill emanating from the use of satellite data, especially cloud track winds and temperature profiles. In climate, empirical studies and numerical experiments point to the feasibility of useful climate predictions on monthly and seasonal time scales. They also indicate the kinds of surface boundary conditions to which climate is sensitive and which need to be observed from space.

  7. Cloud information for FIRE from surface weather reports

    NASA Technical Reports Server (NTRS)

    Hahn, Carole J.; Warren, Stephen G.; London, Julius

    1990-01-01

    Surface weather observations of clouds were analyzed to obtain a global cloud climatology (Warren et al, 1986; 1988). The form of the synoptic weather code limits the types of cloud information which are available from these reports. Comparison of surface weather reports with instrumental observations during the FIRE field experiments can help to clarify the operational definitions which were made in the climatology because of the nature of the synoptic code. The long-term climatology from surface weather observations is also useful background for planning the location and timing of intensive field experiments.

  8. SPACE WEATHER OBSERVING SYSTEMS: CURRENT CAPABILITIES AND

    E-print Network

    Schrijver, Karel

    - REPORT ON SPACE WEATHER OBSERVING SYSTEMS: CURRENT CAPABILITIES AND REQUIREMENTS FOR THE NEXT and Supporting Research National Space Weather Program Council Joint Action Group for Space Environmental Gap of the President #12;ii NATIONAL SPACE WEATHER PROGRAM COUNCIL (NSWPC) MR. SAMUEL P. WILLIAMSON, Chairman Federal

  9. Statistics of link blockage due to cloud cover for free-space optical communications using NCDC surface weather observation data

    NASA Technical Reports Server (NTRS)

    Slobin, S. D.; Piazzolla, S.

    2002-01-01

    Cloud opacity is one of the main atmospheric physical phenomena that can jeopardize the successful completion of an optical link between a spacecraft and a ground station. Hence, the site location chosen for a telescope used for optical communications must rely on knowledge of weather and cloud cover statistics for the geographical area where the telescope itself is located.

  10. Coupling convectively driven atmospheric circulation to surface rotation: Evidence for active methane weather in the observed spin rate drift of Titan

    E-print Network

    Jonathan L. Mitchell

    2009-02-16

    A large drift in the rotation rate of Titan observed by Cassini provided the first evidence of a subsurface ocean isolating the massive core from the icy crust. Seasonal exchange of angular momentum between the surface and atmosphere accounts for the magnitude of the effect, but observations lag the expected signal by a few years. We argue that this time lag is due to the presence of an active methane weather cycle in the atmosphere. An analytic model of the seasonal cycle of atmospheric angular momentum is developed and compared with time-dependent simulations of Titan's atmosphere with and without methane thermodynamics. The disappearance of clouds at the summer pole suggests the drift rate has already switched direction, signaling the change in season from solstice to equinox.

  11. All-weather land surface skin temperatures from a combined analysis of microwave and infrared satellite observations

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The surface skin temperature (Ts) is a key parameter at the land-atmosphere interface. Upwelling longwave radiation directly epends upon Ts. Energy exchanges at the land-surface boundary are largely controlled by the difference between Ts and the surface air temperature, the air and the surface reac...

  12. Surface mass-balance observations and automatic weather station data along a transect near Kangerlussuaq, West Greenland

    Microsoft Academic Search

    W. Greuell; M. R. van den Broeke; C. H. Reijmer; J. Oerlemans

    2005-01-01

    Surface mass-balance data from the Kangerlussuaq transect (K-transect) located on the western part of the Greenland ice sheet near 67° N are presented. The series covers the period 1990-2003 and is the longest series of surface mass-balance measurements in Greenland. The surface massbalance measurements cover an altitude range of 390-1850 m and show a linear increase of the specific mass

  13. Surface mass-balance observations and automatic weather station data along a transect near Kangerlussuaq, West Greenland

    Microsoft Academic Search

    W. Greuell; M. R. van den Broeke; C. H. Reijmer; J. Oerlemans

    2005-01-01

    Surface mass-balance data from the Kangerlussuaq transect (K-transect) located on the western part of the Greenland ice sheet near 678 N are presented. The series covers the period 1990- 2003 and is the longest series of surface mass-balance measurements in Greenland. The surface mass- balance measurements cover an altitude range of 390-1850 m and show a linear increase of the

  14. Observations of the radiation divergence in the surface layer and its implication for its parameterization in numerical weather prediction models

    Microsoft Academic Search

    G. J. Steeneveld; M. J. J. Wokke; C. D. Groot Zwaaftink; S. Pijlman; B. G. Heusinkveld; A. F. G. Jacobs; A. A. M. Holtslag

    2010-01-01

    This paper presents the results of 5 months of in situ observations of the diurnal cycle of longwave radiative heating rate in the lower part of the atmospheric boundary layer over grassland, with a particular focus on nighttime conditions. The observed longwave radiative heating is minimal at the evening transition, with a median value of ?1.8 K h?1 between 1.3

  15. Regional chemical weather forecasting system CFORS: Model descriptions and analysis of surface observations at Japanese island stations during the ACE-Asia experiment

    Microsoft Academic Search

    I. Uno; G. R. Carmichael; D. G. Streets; Y. Tang; J. J. Yienger; S. Satake; Z. Wang; Jung-Hun Woo; S. Guttikunda; M. Uematsu; K. Matsumoto; H. Tanimoto; K. Yoshioka; T. Iida

    2003-01-01

    The Chemical Weather Forecast System (CFORS) is designed to aid in the design of field experiments and in the interpretation\\/postanalysis of observed data. The system integrates a regional chemical transport model with a multitracer, online system built within the Regional Atmospheric Modeling System (RAMS) mesoscale model. CFORS was deployed in forecast and postanalysis modes during the NASA Global Tropospheric Experiment

  16. Rates of oxidative weathering on the surface of Mars

    NASA Technical Reports Server (NTRS)

    Burns, Roger G.

    1992-01-01

    Implicit in the mnemonic 'MSATT' (Mars surface and atmosphere through time) is that rates of surface processes on Mars through time should be investigated, including studies of the kinetics and mechanism of oxidative weathering reactions occurring in the Martian regolith. Such measurements are described. Two major elements analyzed in the Viking Lander XRF experiment that are most vulnerable to atmospheric oxidation are iron and sulfur. Originally, they occurred as Fe(2+)-bearing silicate and sulfide minerals in basaltic rocks on the surface of Mars. However, chemical weathering reactions through time have produced ferric- and sulfate-bearing assemblages now visible in the Martian regolith. Such observations raise several question about: (1) when the oxidative weathering reactions took place on Mars; (2) whether or not the oxidized regolith is a fossilized remnant of past weathering processes; (3) deducting chemical interactions of the ancient Martian atmosphere with its surface from surviving phases; (4) possible weathering reactions still occurring in the frozen regolith; and (5) the kinetics and mechanism of past and present-day oxidative reactions on Mars. These questions may be addressed experimentally by studying reaction rates of dissolution and oxidation of basaltic minerals, and by identifying reaction products forming on the mineral surfaces. Results for the oxidation of pyrrhotite and dissolved ferrous iron are reported.

  17. Observational Data Analysis and Numerical Model Assessment of the Seafloor Interaction and Mobility of Sand and Weathered Oil Agglomerates (Surface Residual Balls) in the Surf Zone

    NASA Astrophysics Data System (ADS)

    Dalyander, S.; Long, J.; Plant, N. G.; Penko, A.; Calantoni, J.; Thompson, D.; Mclaughlin, M. K.

    2014-12-01

    When weathered oil is transported ashore, such as during the Deepwater Horizon oil spill, it can mix with suspended sediment in the surf zone to create heavier-than-water sand and oil agglomerates in the form of mats several centimeters thick and tens of meters long. Broken off pieces of these mats and smaller agglomerates formed in situ (called Surface Residual Balls, SRBs) can cause beach re-oiling months to years after the initial spill. The physical dynamics of these SRBs in the nearshore, where they are larger (cm-scale) and less dense than natural sediment, are poorly understood. In the current study, SRB mobility and seafloor interaction is investigated through a combination of laboratory and field experiments with pseudo-SRBs developed to be physically stable proxies for genuine agglomerates. Formulations for mobility prediction based on comparing estimated shear stress to the critical Shields and modified Shields parameters developed for mixed sediment beds are assessed against observations. Processes such as burial, exhumation, and interaction with bedforms (e.g., migrating ripples) are also explored. The observations suggest that incipient motion estimates based on a modified Shields parameter have some skill in predicting SRB movement, but that other forcing mechanisms such as pressure gradients may be important under some conditions. Additionally, burial and exhumation due to the relatively high mobility of sand grains are confirmed as key processes controlling SRB dynamics in the surf zone. This work has broad implications for understanding surf zone sediment transport at the short timescale associated with mobilizing sand grains and SRBs as well as at the longer timescales associated with net transport patterns, sediment budgets, and bed elevation changes.

  18. SURFACE WATER VAPOR EXCHANGES ON THE GREENLAND ICE SHEET DERIVED FROM AUTOMATED WEATHER STATION DATA

    E-print Network

    Box, Jason E.

    1 SURFACE WATER VAPOR EXCHANGES ON THE GREENLAND ICE SHEET DERIVED FROM AUTOMATED WEATHER STATION.D. Geography) Surface Water Vapor Exchanges on the Greenland Ice Sheet Derived From Automated Weather Station observations are used to estimate surface water vapor exchanges at Greenland ice sheet sites and for the ice

  19. Weather

    NSDL National Science Digital Library

    Ms. LAi

    2007-02-08

    This project will help you understand the weather and investigate weather interactively. What are the components of weather? How do you measure weather? Investigate the WeatherScholastic: Weather WatchWeatherWeather Center for Our 4th Grade ...

  20. Observing Space Weather towards building Predictive Capabilities

    NASA Astrophysics Data System (ADS)

    Bothmer, Volker

    2012-07-01

    Simultaneous data from multi-point space missions operating in the Sun-Earth system in conjunction with dedicated ground- based networks have facilitated major steps towards the quantification of space weather processes, better understandings of their impacts on the various high level systems of modern societal infrastructure and fundamental developments in space weather forecasting. Through the EU FP7 program and the ESA Space Situational Awareness (SSA) program several dedicated space weather projects and studies have currently been initiated, such as the AFFECTS (Advanced Forecast For Ensuring Communications Through Space), aiming in establishing prototype space weather services, instruments and missions as precursors of a future space weather operational system. This presentation provides an overview of the ongoing European activities, upcoming challenges and opportunities for international collaborations.

  1. NASA Scatterometer Provides Global Ocean-Surface Wind Fields with More Structures than Numerical Weather Prediction

    NASA Technical Reports Server (NTRS)

    Liu, W. T.; Tang, W.; Polito, P. S.

    1998-01-01

    The major differences between monthly-mean ocean-surface wind fields derived from the observations of the National Aeronautics and Space Administration (NASA) Scatterometer (NSCAT) and produced by the operational numerical weather prediction (NWP) model of the European Center for Medium-Range Weather Forecasts are found in coastal and equatorial regions, where the sharp changes are smoothed over in NWP products.

  2. Rock Rinds at Meridiani and Surface Weathering Phenomena

    NASA Astrophysics Data System (ADS)

    Jolliff, B.; Knoll, A.; Farrand, W.; Sullivan, R.

    2006-12-01

    The Rock Abrasion Tool (RAT) on the Mars rover Opportunity can brush away surface dust and grind away outcrop surface, exposing presumably less altered rock at depths of several mm. Alpha particle X-ray spectrometer (APXS) and Moessbauer spectrometer (MB) analyses of pre- and post-RAT targets, thus, provide information on the chemical nature of weathering of Meridiani outcrop rocks. To date, Opportunity has analyzed some 25 undisturbed rock surfaces, brushed and then analyzed 7 more, and ground 23 targets for IDD analysis. Panoramic camera images show that outcrop surfaces are typically either buff or purple (as viewed in bands centered at 673, 535, and 432 nm, Farrand et al., JGR, in press). Relatively flat surfaces that are approximately parallel to the ground are typically buff, whereas those that slope steeply tend to be purple. Surfaces of rock interiors ground by the RAT are also commonly purple. Spectrally, these color differences correspond to more oxidized (buff) and less oxidized (purple), and appear to relate to the degree of eolian abrasion. Flat-lying surfaces are not eroded as quickly, thus surfaces chemically weathered by exposure to tenuous atmospheric vapor may be preserved. These observations are consistent with in-situ analyses of rock surfaces and interiors. Compared to interiors, rock surfaces have about 1/3 less S, and in general, surface compositions lie between those of rock interiors and average surface soil. In detail, they differ from soil-rock mixtures as follows: surfaces are relatively depleted in Mg, Fe, Mn, Ti, and Cr, and they are enriched in Al, Na, K, P, Cl, and Si. From MB analyses, surfaces are richer (compared to soil-rock mixtures) in oxidized Fe phases and poorer in magnetite, olivine, and pyroxene. Morphologically, numerous flat-lying rocks and outcrop surfaces that are at or near the ground surface have a rind of erosionally resistant material. Such rinds are also chemically distinct from outcrop interiors. A rind/subjacent rock pair analyzed in detail was "Lemon Rind" and "Strawberry," ca. sols 555-560. The rind is depleted in S (balanced mainly by increased Si and Al) and, compared to a soil-rock mixture, it is depleted in Mg, Ti, Cr, Mn, and slightly in Fe, and it is enriched in Na, Cl, K, and P. Differences between rock surfaces and interiors, and between hardened weathering rinds and rock interiors, are consistent with loss of Mg-sulfate, oxidation of mafic minerals, enrichment of siliciclastic material, e.g., feldspar, and enrichment in chloride. These changes are consistent with slow rates of chemical weathering via interaction with small amounts of atmospheric water vapor or condensation. Erosionally resistant rinds may be related to preservation of aqueous condensate by a thin cover of soil on flat, near-surface rocks.

  3. Measuring stone weathering in cities: Surface reduction on marble monuments

    SciTech Connect

    Dragovich, D. (Univ. of Sydney, New South Wales (Australia))

    1987-01-01

    The purpose of this study was to establish whether measurements of stone weathering recorded by different observers could be aggregated into a simple data base for evaluating pollution effects on calcareous building stone. Apparent differences in recorded weathering rates on marble tombstones were here found to be partly a result of lettering size measured, measuring devices used, and individual observers.

  4. Surface Particle Detectors in Space Weather forecast

    NASA Astrophysics Data System (ADS)

    Chilingarian, Ashot

    Recently several groups report on the development of the alarm system based on the surface particle detector data. Among them are high-latitude neutron monitors network "Spaceship Earth", coordinated by the group from Bartol Research Center; Muon network coordinated by the group from Shinshu University and Athens Neutron Monitor Data Processing Center. In the presented report, based on the information content of data from particle detectors of Aragats Space Environmental Center (ASEC) we made attempt to review possibility of surface particle detectors in Space Weather forecasts. Particle monitors located at ASEC at 1000, 2000 and 3200 m altitudes (40?25 N, 44?15 E; Vertical cut-off rigidity in 2007: 7.1 GV) detect charged and neutral components of the secondary cosmic rays with different energy thresholds and various angles of incidence. ASEC monitors reliably detect the highest energy CR due to unique geographical location and large underground high energy muon detector. Forecasting of the Solar Energetic Proton (SEP) events by surface particle detectors is based on the detection of the Ground Level Enhancements (GLE). Unfortunately not all SEPs contain particles energetic enough to produce GLE, therefore, the efficiency of the warnings will not be very high. Nonetheless, we can expect that the major events, (like 1859, 1956, 1972, 1989) with high probability will generate GLEs and surface detectors can provide forewarnings on upcoming abundant SEP particles. With the exception of the event on 20 January, when due to very good magnetic connection of the flare site with earth, all relativistic particles seem to come simultaneously, the enhancements of GeV solar particles detected by surface particle detectors can alert on upcoming severe radiation storm. The alerts from middle and low latitude monitors are even more important compared to high latitude networks, because of lower probability of false alarms. If an enhancement occurs at monitors with large cutoff rigidity it indicates that spectral knee occurs at large enough energy. Enhancements in the ASEC detectors count rates indicate higher solar ion energies, and, consequently hard spectra of the GLE in progress. The triggers of the Geomagnetic Storms are huge magnetized clouds (Coronal mass ejections - CMEs), emitted by sun and traveling in the Interplanetary Space (IP). This gigantic plasma clouds with "frozen" magnetic field (Interplanetary CMEs, - ICMEs) disturb the Interplanetary Magnetic Field and "modulate "the ambient flux of the Galactic Cosmic rays (GCR). On the way to Earth (15 - 70 hours) the magnetic cloud and shock change GCR intensity and make it anisotropic. The strength of these modulation effects correlate with severity of the geomagnetic storm. Networks of the particle detectors located on Earth surface detect these modulation effects and can predict the upcoming geomagnetic storms hours before the ICME arrival at the magnetometers on ACE and SOHO space stations. We will demonstrate that simultaneously detection of the charged and neutral components of the secondary cosmic rays made by ASEC monitors enlarged possibilities of physical inference on the solar modulation effects and, therefore, enlarges possibilities of timely and reliable forecasts of dangerous consequences of radiation and geomagnetic storms.

  5. Generation of Multivariate Surface Weather Series with Use of the Stochastic Weather Generator Linked to Regional Climate Model

    NASA Astrophysics Data System (ADS)

    Dubrovsky, M.; Farda, A.; Huth, R.

    2012-12-01

    The regional-scale simulations of weather-sensitive processes (e.g. hydrology, agriculture and forestry) for the present and/or future climate often require high resolution meteorological inputs in terms of the time series of selected surface weather characteristics (typically temperature, precipitation, solar radiation, humidity, wind) for a set of stations or on a regular grid. As even the latest Global and Regional Climate Models (GCMs and RCMs) do not provide realistic representation of statistical structure of the surface weather, the model outputs must be postprocessed (downscaled) to achieve the desired statistical structure of the weather data before being used as an input to the follow-up simulation models. One of the downscaling approaches, which is employed also here, is based on a weather generator (WG), which is calibrated using the observed weather series and then modified (in case of simulations for the future climate) according to the GCM- or RCM-based climate change scenarios. The present contribution uses the parametric daily weather generator M&Rfi to follow two aims: (1) Validation of the new simulations of the present climate (1961-1990) made by the ALADIN-Climate/CZ (v.2) Regional Climate Model at 25 km resolution. The WG parameters will be derived from the RCM-simulated surface weather series and compared to those derived from observational data in the Czech meteorological stations. The set of WG parameters will include selected statistics of the surface temperature and precipitation (characteristics of the mean, variability, interdiurnal variability and extremes). (2) Testing a potential of RCM output for calibration of the WG for the ungauged locations. The methodology being examined will consist in using the WG, whose parameters are interpolated from the surrounding stations and then corrected based on a RCM-simulated spatial variability. The quality of the weather series produced by the WG calibrated in this way will be assessed in terms of selected climatic characteristics focusing on extreme precipitation and temperature characteristics (including characteristics of dry/wet/hot/cold spells). Acknowledgements: The present experiment is made within the frame of projects ALARO (project P209/11/2405 sponsored by the Czech Science Foundation), WG4VALUE (project LD12029 sponsored by the Ministry of Education, Youth and Sports) and VALUE (COST ES 1102 action).

  6. Weather

    NSDL National Science Digital Library

    Ms. Stearns

    2008-10-25

    This is a first grade weather unit. SEASONS Fall Winter Build a Snowman Spring Summer What things determine and effect the weather? Cloud Precipitation Sunshine Temperature Visibility Wind Direction Wind Force WEATHER VIDEOS Tornado Hurricane Hail Lightning FUN AND GAMES Dress the Bear for the Weather The Great Weather Race Game Weather coloring books for kids ...

  7. SEVIRI rainfall retrieval and validation using weather radar observations

    NASA Astrophysics Data System (ADS)

    Roebeling, R. A.; Holleman, I.

    2009-11-01

    This paper presents and validates a new algorithm to detect precipitating clouds and estimate rain rates from cloud physical properties retrieved from the Spinning Enhanced Visible and Infrared Imager (SEVIRI). The precipitation properties (PP) algorithm uses information on cloud condensed water path (CWP), particle effective radius, and cloud thermodynamic phase to detect precipitating clouds, while information on CWP and cloud top height is used to estimate rain rates. An independent data set of weather radar data is used to determine the optimum settings of the PP algorithm and calibrated it. For a 2-month period, the ability of SEVIRI to discriminate precipitating from nonprecipitating clouds is evaluated using weather radar over the Netherlands. In addition, weather radar and rain gauge observations are used to validate the SEVIRI retrievals of rain rate and accumulated rainfall across the entire study area and period. During the observation period, the spatial extents of precipitation over the study area from SEVIRI and weather radar are highly correlated (correlation ? 0.90), while weaker correlations (correlation ? 0.63) are found between the spatially mean rain rate retrievals from these instruments. The combined use of information on CWP, cloud thermodynamic phase, and particle size for the detection of precipitation results in an increase in explained variance (˜10%) and decrease in false alarms (˜15%), as compared to detection methods that are solely based on a threshold CWP. At a pixel level, the SEVIRI retrievals have an acceptable accuracy (bias) of about 0.1 mm h-1 and a precision (standard error) of about 0.8 mm h-1. It is argued that parts of the differences are caused by collocation errors and parallax shifts in the SEVIRI data and by irregularities in the weather radar data. In future studies we intend to exploit the observations of the European weather radar network Operational Programme for the Exchange of Weather Radar Information (OPERA) and extend this study to the entirety of Europe.

  8. State of the Atmosphere: Interpreting Weather Observations

    NSDL National Science Digital Library

    Kim LaFrance

    The purpose of this lesson is to let students analyze atmospheric radiosonde data from a balloon launched at NASA Langley Research Center by teachers attending a workshop. Other resources are included to assist in interpreting the observations. Students are asked to explain in paragraph format their interpretation of the atmospheric conditions depicted by the data and the graph produced using the data.

  9. Surface chemistry associated with the cooling and subaerial weathering of recent basalt flows

    USGS Publications Warehouse

    White, A.F.; Hochella, M.F., Jr.

    1992-01-01

    The surface chemistry of fresh and weathered historical basalt flows was characterized using surface-sensitive X-ray photoelectron spectroscopy (XPS). Surfaces of unweathered 1987-1990 flows from the Kilauea Volcano, Hawaii, exhibited variable enrichment in Al, Mg, Ca, and F due to the formation of refractory fluoride compounds and pronounced depletion in Si and Fe from the volatilization of SiF4 and FeF3 during cooling. These reactions, as predicted from shifts in thermodynamic equilibrium with temperature, are induced by diffusion of HF from the flow interiors to the cooling surface. The lack of Si loss and solid fluoride formation for recent basalts from the Krafla Volcano, Iceland, suggest HF degassing at higher temperatures. Subsequent short-term subaerial weathering reactions are strongly influenced by the initial surface composition of the flow and therefore its cooling history. Successive samples collected from the 1987 Kilauea flow demonstrated that the fluoridated flow surfaces leached to a predominantly SiO2 composition by natural weathering within one year. These chemically depleted surfaces were also observed on Hawaiian basalt flows dating back to 1801 AD. Solubility and kinetic models, based on thermodynamic and kinetic data for crystalline AlF3, MgF2, and CaF2, support observed elemental depletion rates due to chemical weathering. Additional loss of alkalis from the Hawaiian basalt occurs from incongruent dissolution of the basalt glass substrate during weathering. ?? 1992.

  10. Naturally weathered feldspar surfaces in the Navajo Sandstone aquifer, Black Mesa, Arizona: Electron microscopic characterization

    Microsoft Academic Search

    Chen Zhu; David R. Veblen; Alex E. Blum; Stephen J. Chipera

    2006-01-01

    Naturally weathered feldspar surfaces in the Jurassic Navajo Sandstone at Black Mesa, Arizona, was characterized with high-resolution transmission and analytical electron microscope (HRTEM-AEM) and field emission gun scanning electron microscope (FEG-SEM). Here, we report the first HRTEM observation of a 10-nm thick amorphous layer on naturally weathered K-feldspar in currently slightly alkaline groundwater. The amorphous layer is probably deficient in

  11. Surface reactions during the early stages of weathering of albite

    Microsoft Academic Search

    Roland Wollast; Lei Chou

    1992-01-01

    The aim of this study is to gain a better understanding of the nature and distribution of surface species occurring during the initial stage of weathering of albite. Instead of the classical acidbase titration experiments used extensively in previous work, the surface of freshly ground mineral was titrated by adding increasing amounts of solid to pure water. The aqueous phase

  12. Aviation Weather Observations for Supplementary Aviation Weather Reporting Stations (SAWRS) and Limited Aviation Weather Reporting Stations (LAWRS). Federal Meteorological Handbook No. 9.

    ERIC Educational Resources Information Center

    Department of Transportation, Washington, DC.

    This handbook provides instructions for observing, identifying, and recording aviation weather at Limited Aviation Weather Reporting Stations (LAWRS) and Supplementary Aviation Weather Reporting Stations (SAWRS). Official technical definitions, meteorological and administrative procedures are outlined. Although this publication is intended for use…

  13. Weather

    NSDL National Science Digital Library

    Rachelle Tuttle

    2005-10-25

    Meteorologists study the weather by recording and analyzing data. You can become an amateur meteorologist by building your own weather station and keeping a record of your measurements. After a while, you\\'ll notice the weather patterns that allow meteorologists to forecast the weather. Tasks: 1. As a group you will build a weather station outside. 2. Your group will build instruments to measure the weather. 3. Each person will record the data in personal weather journals. Process: 1.Since weather happens outside, you\\'ll need to make ...

  14. DETECTION OF A LARGE VARIATION IN THE DEGREE OF SPACE WEATHERING ON THE SURFACE OF ITOKAWA BY HAYABUSA/AMICA OBSERVATIONS. M. Ishiguro

    E-print Network

    Hiroi, Takahiro

    . Yoshida 6 , B. E. Clark 7 , R. Nakamura 8 and J. Saito 9 , 1 School of Earth Environmental Sciences was observed on the sur- faces of S-type asteroids 951 Gaspra, 243 Ida, and 433 Eros [4-5], whose diameters incident light are 0.38 µm (ul band), 0.43 µm (b band), 0.55 µm (v band), 0.70 µm (w band), 0.86 µm (x band

  15. Land-surface influences on weather and climate

    NASA Technical Reports Server (NTRS)

    Baer, F.; Mintz, Y.

    1984-01-01

    Land-surface influences on weather and climate are reviewed. The interrelationship of vegetation, evapotranspiration, atmospheric circulation, and climate is discussed. Global precipitation, soil moisture, the seasonal water cycle, heat transfer, and atmospheric temperature are among the parameters considered in the context of a general biosphere model.

  16. Recent Near-Neutral Chemical Weathering of Martian High-Latitude Surfaces

    NASA Astrophysics Data System (ADS)

    Kraft, M. D.; Michalski, J. R.; Sharp, T. G.; Rampe, E. B.

    2006-12-01

    Recent scientific investigations of Mars, including those conducted by TES, OMEGA, and the MER lander missions, have expanded the discussion about aqueous alteration on Mars. Results from these missions indicate that the styles and/or intensity of water-rock interactions on Mars have changed over time, and they provide evidence for geographical differences in weathering typically associated with latitude. Work that we have done on the spectroscopy of terrestrial weathering rinds and rock coatings indicates that small volumes of weathering products mixed with primary minerals considerably change thermal emission spectra of volcanic rocks. Based on that work, we suggest that low-intensity chemical weathering leading to the formation of small volumes of weathering products can explain the global distribution of TES observations. Whereas MER results indicate acidic alteration at low latitudes since the late Noachian, we suggest that major surface- mineralogical differences observed by TES (and broadly corroborated by OMEGA) may be due to near-neutral pH chemical weathering, pedogenically driven by near-surface pore waters at mid-to-high latitudes.

  17. Weather observations on Whistler Mountain during five storms

    NASA Astrophysics Data System (ADS)

    Thériault, Julie M.; Rasmussen, Kristen L.; Fisico, Teresa; Stewart, Ronald E.; Joe, Paul; Gultepe, Ismail; Clément, Marilys; Isaac, George A.

    2014-01-01

    A greater understanding of precipitation formation processes over complex terrain near the west coast of British Colombia will contribute to many relevant applications, such as climate studies, local hydrology, transportation, and winter sport competition. The phase of precipitation is difficult to determine because of the warm and moist weather conditions experienced during the wintertime in coastal mountain ranges. The goal of this study is to investigate the wide range of meteorological conditions that generated precipitation on Whistler Mountain from 4-12 March 2010 during the SNOW-V10 field campaign. During this time period, five different storms were documented in detail and were associated with noticeably different meteorological conditions in the vicinity of Whistler Mountain. New measurement techniques, along with the SNOW-V10 instrumentation, were used to obtain in situ observations during precipitation events along the Whistler mountainside. The results demonstrate a high variability of weather conditions ranging from the synoptic-scale to the macro-scale. These weather events were associated with a variation of precipitation along the mountainside, such as events associated with snow, snow pellets, and rain. Only two events associated with a rain-snow transition along the mountainside were observed, even though above-freezing temperatures along the mountainside were recorded 90 % of the time. On a smaller scale, these events were also associated with a high variability of snowflake types that were observed simultaneously near the top of Whistler Mountain. Overall, these detailed observations demonstrate the importance of understanding small-scale processes to improve observational techniques, short-term weather prediction, and longer-term climate projections over mountainous regions.

  18. Two cases of severe weather in Catalonia (Spain): an observational study

    Microsoft Academic Search

    Clemente Ramis; Joan Arús; José Manuel López; Antoni M. Mestres

    1997-01-01

    Surface observations, satellite and radar imagery and cloud-to-ground lightning data are used in an observational study of two cases that produced severe weather in Catalonia (Spain). The first one occurred on 24 August 1993; a squall line crossed Catalonia from west to east producing heavy rain with rates of up to 100 mm h[minus sign]1 and hail of 7 cm

  19. Weather

    NSDL National Science Digital Library

    Ms. Hendricks

    2007-12-06

    Introduction: How much do you know about weather? What kinds of weather do we have surrounding us? What is the weather like today? You may know a lot about weather already, you may not. Either way, you will learn more now as we take a look into what causes our weather and the methods we use to record and predict it. We will all become meteorologists, which are scientists who study the atmosphere and can predict weather. Put on your raincoats, and lets started! Task: You are the resident meteorologist at a local news station. It is your job to record and predict the weather each day, and then present it that night on the evening news. Not only should you be able to show the weather that we will be experiencing right ...

  20. Weather

    NSDL National Science Digital Library

    The National Oceanic and Atmospheric Administration (NOAA) provides these two Websites on weather. The first site serves as a major hub for information related to weather, with links to primary data sources, forecasts, maps, images (such as the latest satellite imagery for North America), and a wealth of other data, including space weather. Researchers will also find links to national weather research centers and other related agencies.

  1. Weather

    NSDL National Science Digital Library

    Miss Jennie

    2009-10-22

    What are the different types of weather? In this project you will compare different types of weather by drawing pictures and making it into a flip book. First you will begin by learning about the different types of weather. Read about each topic. Then get together with your partner and draw a picture of each type of weather. 1. Thunder storm Thunder storm Thunder storm Kids 2. Lightning Lightning Lightning picture 3. Tornado Tornadoes Tornado Kids 4. ...

  2. Mobile vehicle road and weather observation quality check methods

    NASA Astrophysics Data System (ADS)

    Koller, Daniel Raymond

    Today State Departments of Transportation rely more and more on road weather data to make maintenance decisions. Inaccurate data can result in wrong treatment applications or inadequate staffing levels to maintain the roadway at the desired level of service. Previous methods of road condition data reporting have been limited to static in situ sensor stations. These road weather information systems (RWIS) provide varied data about precipitation, winds, temperature, and more, but their siting does not always provide an accurate representation of weather and road conditions along the roadway. The use of mobile data collection from vehicles travelling the highway corridors may assist in the locations where RWIS sitings are sparse or non-existent. The United States Department of Transporation's "Connected Vehicle" (formally IntelliDrive) research project is designed to create a fully connected transportation system providing road and weather data collection from an extensive array of vehicles. While the implementation of Connected Vehicle is in the future, some of the theories and technologies are already in place today. Several states, as a part of the Pooled Fund Study Maintenance Decision Support System (MDSS), have equipped their winter maintenance vehicles with Mobile Data Collection Automated / Vehicle Location (MDC/AVL) systems. In addition, since 1996, automobiles sold in the United States are required to be equipped with an Onboard Diagnostic Version 2 (OBDII) port that streams live data from sensors located in and around the vehicle. While these sensors were designed for vehicle diagnostics, some of the data can be used to determine weather characteristics around the vehicle. The OBDII data can be collected by a smartphone and sent to a server in real time to be processed. These mobile systems may fill the information gap along the roads that stationary environmental sensor stations are not able to collect. Particular concern and care needs to be focused on data quality and accuracy, requiring the development of quality checks for mobile data collection. Using OBDII-equipped automobiles and mobile collection methods, we can begin to address issues of data quality by understanding, characterizing, and demonstrating the quality of mobile system observations from operational and research environments. Several forms of quality checking can be used, including range checks, Barnes spatial checks, comparing vehicle data to road weather models, and applying Clarus quality check methodologies and algorithms to mobile observations. Development of these quality checks can lead to the future integration of mobile data into the Clarus system, data implementation for improved forecasting, maintenance decision support, and traveler safety. This paper will discuss the benefits and challenges in mobile data collection, along with how the development and implementation of a system of quality checks will improve the quality and accuracy of mobile data collection.

  3. Observations and Modeling of Space Weather Impacts on the Earth

    NASA Astrophysics Data System (ADS)

    Solomon, Stanley C.

    2006-10-01

    ``Space weather'' refers to conditions in the solar wind, magnetosphere, ionosphere, and upper atmosphere, that influence space-borne and ground-based technological systems and can endanger human space exploration. These effects are caused by variations in solar photon and particle radiation due to flares and coronal mass ejections, and changes in the solar/interplanetary magnetic field, that impact the magnetosphere and ionosphere. Space weather can initiate satellite failures, interfere with radio communications, cause navigation errors, disrupt electrical power distribution systems, and expose astronauts to dangerous levels of radiation. Mitigation requires both a better understanding of the space environment, and developing the ability to forecast conditions in space. The development of first-principles numerical models of the solar-terrestrial system gives us insight into the causes and nature of these phenomena, and holds the promise of ultimately being able to acquire a short-term predictive capability for some of them. This presentation will describe what we do and don't understand about the basic physics behind space weather, discuss some of its aspects and effects, and describe the latest observational and modeling efforts

  4. On the Use of QuikSCAT Scatterometer Measurements of Surface Winds for Marine Weather Prediction

    E-print Network

    Kurapov, Alexander

    and ECMWF global numerical weather prediction models considerably underestimated the spatial variability Centre for Medium-Range Weather Forecasts (ECMWF) global numerical weather prediction (NWP) modelsOn the Use of QuikSCAT Scatterometer Measurements of Surface Winds for Marine Weather Prediction

  5. Two cases of severe weather in Catalonia (Spain): an observational study

    NASA Astrophysics Data System (ADS)

    Ramis, Clemente; Arús, Joan; López, José Manuel; Mestres, Antoni M.

    1997-09-01

    Surface observations, satellite and radar imagery and cloud-to-ground lightning data are used in an observational study of two cases that produced severe weather in Catalonia (Spain). The first one occurred on 24 August 1993; a squall line crossed Catalonia from west to east producing heavy rain with rates of up to 100 mm h[minus sign]1 and hail of 7 cm diameter. The observational information provided is a good tool for monitoring the event and issuing a reasonable nowcast. The second case, which occurred on 31 August 1994, was associated with the development of a tornado (F1 in the Fujita scale) as well as hail of up to 5 cm diameter. In this case the convection was almost stationary and no clear signatures of severe weather can be identified from available satellite and radar imagery.

  6. Weather

    NSDL National Science Digital Library

    Edheads offers a Macromedia Flash Player enhanced interactive module allowing students to predict the weather by examining weather maps. Through this website, users can become familiar with the concepts of warm and cold fronts, wind direction and speed, air pressure, and humidity. Teachers looking to incorporate this site in their classroom can check out the "Teacher's Guide" for helpful hints on using the site with students.

  7. Bacillus qingshengii sp. nov., a rock-weathering bacterium isolated from weathered rock surface.

    PubMed

    Xi, Jun; He, Lin-Yan; Huang, Zhi; Sheng, Xia-Fang

    2014-07-01

    A novel type of rock-weathering bacterium was isolated from weathered rock (tuff) surface collected from Dongxiang (Jiangxi, eastern China). Cells of strain G19(T) were Gram-reaction-positive, rod-shaped, endospore-forming and non-motile. The strain was aerobic, catalase- and oxidase-positive, and grew optimally at 30 °C and pH 7.0. On the basis of 16S rRNA gene sequence analysis, strain G19(T) was shown to belong to the genus Bacillus and the closest phylogenetic relatives were Bacillus aryabhattai B8W22(T) (97.4%) and Bacillus megaterium IAM 13418(T) (97.1%). The DNA G+C content was 36.7 mol% and the predominant respiratory quinone was MK-7. The major fatty acids were iso-C14 : 0, iso-C15 : 0 and anteiso-C15 : 0. The polar lipid profile of strain G19(T) contained phosphatidylglycerol, phosphatidylethanolamine, diphosphatidylglycerol and an unidentified lipid. Based on the low level of DNA-DNA relatedness (ranging from 49.4% to 55.0%) to these type strains of species of the genus Bacillus and unique phenotypic characteristics, strain G19(T) represents a novel species of the genus Bacillus, for which the name Bacillus qingshengii sp. nov. is proposed. The type strain is G19(T) (?= CCTCC AB 2013273(T)?= JCM 19454(T)). PMID:24801156

  8. Building the Undergraduate Knowledge Base in Observing, Modeling and Forecasting Space Weather

    Microsoft Academic Search

    D. J. Knipp; M. G. McHarg

    2006-01-01

    Although much has been written about space weather, there is little information available at the undergraduate level about the fundamental processes involved in dealing with such a complex system. In this talk we discuss the contents of three chapters in a new undergraduate space weather textbook that deal specifically with the role of observations, models and forecasts in space weather.

  9. An Assessment of the SST Influence on Surface Wind Stress in Numerical Weather Prediction and Climate Models

    E-print Network

    Maloney, Eric

    An Assessment of the SST Influence on Surface Wind Stress in Numerical Weather Prediction;1 Abstract We analyze the ability of six climate models to capture the observed coupling between SST and surface wind stress in the vicinity of strong midlatitude SST fronts. The analysis emphasizes air

  10. Lightning Sensors for Observing, Tracking and Nowcasting Severe Weather

    PubMed Central

    Price, Colin

    2008-01-01

    Severe and extreme weather is a major natural hazard all over the world, often resulting in major natural disasters such as hail storms, tornados, wind storms, flash floods, forest fires and lightning damages. While precipitation, wind, hail, tornados, turbulence, etc. can only be observed at close distances, lightning activity in these damaging storms can be monitored at all spatial scales, from local (using very high frequency [VHF] sensors), to regional (using very low frequency [VLF] sensors), and even global scales (using extremely low frequency [ELF] sensors). Using sensors that detect the radio waves emitted by each lightning discharge, it is now possible to observe and track continuously distant thunderstorms using ground networks of sensors. In addition to the number of lightning discharges, these sensors can also provide information on lightning characteristics such as the ratio between intra-cloud and cloud-to-ground lightning, the polarity of the lightning discharge, peak currents, charge removal, etc. It has been shown that changes in some of these lightning characteristics during thunderstorms are often related to changes in the severity of the storms. In this paper different lightning observing systems are described, and a few examples are provided showing how lightning may be used to monitor storm hazards around the globe, while also providing the possibility of supplying short term forecasts, called nowcasting.

  11. WEATHER OBSERVATIONS - SUMMARY OF THE DAY - FIRST ORDER

    EPA Science Inventory

    The National Climatic Data Center makes available daily weather data for approximately 300 currently active National Weather Service stations, with a lag time (after end of data month) of about 8-10 weeks. Coverage includes the contiguous United States, Caribbean Islands, Pacific...

  12. Burkholderia susongensis sp. nov., a mineral-weathering bacterium isolated from weathered rock surface.

    PubMed

    Gu, Jia-Yu; Zang, Sheng-Gang; Sheng, Xia-Fang; He, Lin-Yan; Huang, Zhi; Wang, Qi

    2015-03-01

    A novel type of mineral-weathering bacterium was isolated from the weathered surface of rock (mica schist) collected from Susong (Anhui, China). Cells of strain L226(T) were Gram-stain-negative. The strain grew optimally at 30 °C, with 1?% (w/v) NaCl and at pH 7.0 in trypticase soy broth. On the basis of 16S rRNA gene phylogeny, strain L226(T) was shown to belong to the genus Burkholderia and the closest phylogenetic relatives were Burkholderia sprentiae WSM5005(T) (98.3?%), Burkholderia acidipaludis NBRC 101816(T) (98.2?%), Burkholderia tuberum STM678(T) (97.2?%) and Burkholderia diazotrophica JPY461(T) (97.1?%). The DNA G+C content was 63.5 mol% and the respiratory quinone was Q-8. The major fatty acids were C16?:?0, C17?:?0 cyclo and C19?:?0 cyclo ?8c. The polar lipid profile of strain L226(T) consisted of a mixture of phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, unknown lipids and unidentified aminophospholipids. Based on the low level of DNA-DNA relatedness (ranging from 25.8?% to 34.4?%) to the tested type strains of species of the genus Burkholderia and unique phenotypic characteristics, it is suggested that strain L226(T) represents a novel species of the genus Burkholderia, for which the name Burkholderia susongensis sp. nov., is proposed. The type strain is L226(T) (?=?CCTCC AB2014142(T)?=?JCM 30231(T)). PMID:25575828

  13. Weather

    NSDL National Science Digital Library

    Ms. Caitlin

    2009-10-21

    In the project you will learn about thunderstorms and tornadoes and play a weather matching game. What exactly are thunderstorms and tornadoes? Use your T- chart to explain some facts about a thunderstorm and a tornado as we review each. T-Chart Begin by reviewing what a thunderstorm is and how they form. Thunderstorm information What is a thunderstorm? What are thunderstorms most likely to occur? What causes thunder? Next review what a tornado ...

  14. Weather Observer, 15-1. Military Curriculum Materials for Vocational and Technical Education.

    ERIC Educational Resources Information Center

    Ohio State Univ., Columbus. National Center for Research in Vocational Education.

    This course, adapted from military curriculum materials for use in vocational and technical education, was designed to upgrade an apprentice weather observer to the weather observer specialist level. Intended to be used in a laboratory or on-the-job learning situation, it contains both basic information needed for review and supervisory…

  15. Aviation & Space Weather Policy Research: Integrating Space Weather Observations & Forecasts into Operations

    Microsoft Academic Search

    G. Fisher; B. Jones

    2006-01-01

    The American Meteorological Society and SolarMetrics Limited are conducting a policy research project leading to recommendations that will increase the safety, reliability, and efficiency of the nation's airline operations through more effective use of space weather forecasts and information. This study, which is funded by a 3-year National Science Foundation grant, also has the support of the Federal Aviation Administration

  16. Observations and Impact Assessments of Extreme Space Weather Events

    NASA Astrophysics Data System (ADS)

    Baker, D. N.

    2007-05-01

    "Space weather" refers to conditions on the Sun, in the solar wind, and in Earth`s magnetosphere, ionosphere, and thermosphere. Activity on the Sun such as solar flares and coronal mass ejections can lead to high levels of radiation in space and can cause major magnetic storms at the Earth. Space radiation can come as energetic particles or as electromagnetic emissions. Adverse conditions in the near-Earth space environment can cause disruption of satellite operations, communications, navigation, and electric power distribution grids. This can lead to a variety of socioeconomic losses. Astronauts and airline passengers exposed to high levels of radiation are also at risk. Society`s vulnerability to space weather effects is an issue of increasing concern. We are dependent on technological systems that are becoming more susceptible to space weather disturbances. We also have a permanent human presence in space with the International Space Station and the President and NASA have expressed a desire to expand our human space activities with missions to the moon and Mars. This will make space weather of even greater concern in the future. In this talk I will describe many space weather effects and will describe some of the societal and economic impacts that extreme events have had.

  17. Weather Specialist/Aerographer's Mate.

    ERIC Educational Resources Information Center

    Chanute AFB Technical Training Center, IL.

    This course trains Air Force personnel to perform duties prescribed for weather specialists and aerographer's mates. Training includes meteorology, surface and ship observation, weather radar, operation of standard weather instruments and communications equipment, and decoding and plotting of surface and upper air codes upon standard maps and…

  18. Introduction to GOES-R and the Next Generation Weather and Observation Constellations

    NASA Astrophysics Data System (ADS)

    Burnett, M.; Krause, R. G.

    2012-12-01

    The Earth Observing community is preparing for the next generation of weather and observation remote sensing systems. These systems are constellations that provide a much richer sensor suite that provides significant increases in data rates, types of data and resultant volumes. In this new era weather and observation data are made more integrated, and multiple mechanisms for accessing this data and dedicated services that leverage it will be made available. The purpose of this presentation will be to introduce this next generation of weather and observation constellations, including the GOES-R system as an example, and to provide a platform for other presentations in this session.

  19. Experimental observations of the effects of bacteria on aluminosilicate weathering

    Microsoft Academic Search

    W. W. Barker; S. A. Welch; S. Chu; J. F. Banfield

    1998-01-01

    Mineral dissolution experiments using batch cultures of soil and groundwater bacteria were monitored with solution chemistry and various microscopic techniques to determine the effects of these organisms on weathering reactions. Several strains of bacteria produced organic and inorganic acids and extracellular polymers in culture, increasing the release of cations from biotite (Si, Fe, Al) and plagioclase feldspar (Si, Al) by

  20. Improving Weather and Climatic Information Quality with User-Generated Observations

    Microsoft Academic Search

    Katarina Elevant; Marko Turpeinen

    2011-01-01

    In this paper we suggest that active participation by civil society may arise through sharing of environmental data – observations of weather and other measurable variables in the environment, performed by individuals. A general model illustrating individual time resources is introduced, in order to map the two studied groups, i.e. school children and adults interested in weather due to their

  1. Characterizing the process and quantifying the rate of subaerial rock weathering on desert surfaces using roughness analysis

    NASA Astrophysics Data System (ADS)

    Mushkin, Amit; Sagy, Amir; Trabelci, Eran

    2013-04-01

    Subaerial weathering of rocks is a common process observed on desert surfaces on Earth and other planetary terrestrial surfaces such as on Mars. On Earth, this weathering process has been previously identified as one of the key erosion agent driving geomorphic surface evolution and the development of desert pavements. And yet, fundamental aspects of the process, such as the relative contribution of the different weathering modes that drive it (e.g., mechanical breakdown of rocks, chemical weathering, aeolian abrasion and exfoliation) as well as the rate by which this weathering process occurs have not been systematically examined. Here, we present a new approach for quantitatively addressing these fundamental aspects of process geomorphology on desert surfaces. We focus here on co-genetic desert alluvial surfaces of different ages, i.e. alluvial chronosequences, which provide excellent recorders for the evolution of boulder-strewn surfaces into smooth desert pavements through in-situ subaerial weathering of rocks. Our approach combines independent measures of two different surface attributes: High resolution (mm-scale) 3D ground-based laser scanning (LiDAR) of surface micro-topography, and numerical dating of surface age. Roughness analysis of the LiDAR data in power spectral density (PSD) space allows us to characterize the geometric manifestation of rock weathering on the surface and to distinguish between the different weathering modes. Numerical age constraints provide independent estimates for the time elapsed since the process began. Accordingly, we are able to constrain surface roughness evolution on alluvial fan desert chronosequences through time, and present PSD analysis of surface roughness as a new quantitative tool to examine the process of subaerial rock weathering in desert environments. In this study we present results from two late Quaternary alluvial chronosequences along the Dead Sea Transform in the hyper-arid Negev desert of southern Israel. LiDAR scanning was applied on representative areas (~30-50 m2) of 10 separate surfaces ranging from rough Holocene surfaces to fairly smooth surfaces with well-developed pavements displaying an OSL age of 87 kyr. We find typical and recurring time-dependent changes in the offset as well as shape of the PSD curves in both chronosequences: PSD offset is continuously reduced over time reflecting the overall reduction in the amplitude of roughness at all wavelengths. The PSD curves display progressive moderation of slopes at the longer wavelengths with the moderation point itself systematically shifted to shorter wavelengths. This characteristic evolution of PSD offset and slope moderation at longer wavelengths reflects the typical break up of boulder-sized clasts through time as the surfaces mature into well-developed desert pavements and points towards mechanical breakdown as the dominant weathering mode. In addition, we are able to determine the rate by which the larger clasts are removed from the system. We build on these new insights into process and rate of rock weathering to propose PSD analysis of surface roughness as a complementary method for constraining the age of desert alluvial surfaces in places where 'conventional' dating cannot be applied.

  2. Titan's rotation - Surface feature observed

    NASA Astrophysics Data System (ADS)

    Lemmon, M. T.; Karkoschka, E.; Tomasko, M.

    1993-06-01

    A surface feature or a near-surface fracture is suggested to account for the time variations in the 0.94, 1.08, and 1.28 micron atmospheric windows of Titan's geometric albedo, relative to its albedo in adjacent methane bands. These observations are noted to be consistent with synchronous rotation. They can also be explained by a 0.1-higher surface albedo on Titan's leading hemisphere.

  3. Surface roughness and color characteristics of wood treated with preservatives after accelerated weathering test

    Microsoft Academic Search

    Ali Temiz; Umit C. Yildiz; Ismail Aydin; Morten Eikenes; Gry Alfredsen; Gürsel Çolakoglu

    2005-01-01

    Wood samples treated with ammonium copper quat (ACQ 1900 and ACQ 2200), chromated copper arsenate (CCA), Tanalith E 3491 and Wolmanit CX-8 have been studied in accelerated weathering experiments. The weathering experiment was performed by cycles of 2h UV-light irradiation followed by water spray for 18min. The changes on the surface of the weathered samples were characterized by roughness and

  4. Mercury's Weather-Beaten Surface: Understanding Mercury in the Context of Lunar and Asteroid Space Weathering Studies

    NASA Technical Reports Server (NTRS)

    Dominque, Deborah L.; Chapman, Clark R.; Killen, Rosemary M.; Zurbuchen, Thomas H.; Gilbert, Jason A.; Sarantos, Menelaos; Benna, Mehdi; Slavin, James A.; Orlando, Thomas M.; Schriver, David; Sprague, Ann L.; Blewett, David T.; Gillis-Davis, Jeffrey J.; Feldman, William C.; Lawrence, David J.; Ho, George C.; Vilas, Faith; Pieters, Carle M.; McClintock, William E.; Helbert, Jorn

    2011-01-01

    Understanding the composition of Mercury's crust is key to comprehending the formation of the planet. The regolith, derived from the crustal bedrock, has been altered via a set of space weathering processes. These processes are the same set of mechanisms that work to form Mercury's exosphere, and are moderated by the local space environment and the presence of an intrinsic planetary magnetic field. The alterations need to be understood in order to determine the initial crustal compositions. The complex interrelationships between Mercury's exospheric processes, the space environment, and surface composition are examined and reviewed. The processes are examined in the context of our understanding of these same processes on the lunar and asteroid regoliths. Keywords: Mercury (planet) Space weathering Surface processes Exosphere Surface composition Space environment 3

  5. Soil Characteristics Related to Weathering and Pedogenesis Across a Geomorphic Surface of Uniform Age in Michigan

    Microsoft Academic Search

    Randall J. Schaetzl; Leslie R. Mikesell; Michael A. Velbel

    2006-01-01

    Our study explores the range of pedogenic development and near-surface weathering on a large (>250,000 ha) geomorphic surface in northern lower Michigan, via the examination of four typical soils. The surface is associated with proglacial outwash from the Port Huron advance of the Laurentide ice sheet, dated at about 13 ka. In a GIS we determined the four most extensive

  6. INDICATION OF INSENSITIVITY OF PLANETARY WEATHERING BEHAVIOR AND HABITABLE ZONE TO SURFACE LAND FRACTION

    SciTech Connect

    Abbot, Dorian S.; Ciesla, Fred J. [Department of the Geophysical Sciences, University of Chicago, 5734 South Ellis Avenue, Chicago, IL 60637 (United States); Cowan, Nicolas B., E-mail: abbot@uchicago.edu [Center for Interdisciplinary Exploration and Research in Astrophysics (CIERA) and Department of Physics and Astronomy, Northwestern University, 2131 Tech Drive, Evanston, IL 60208 (United States)

    2012-09-10

    It is likely that unambiguous habitable zone terrestrial planets of unknown water content will soon be discovered. Water content helps determine surface land fraction, which influences planetary weathering behavior. This is important because the silicate-weathering feedback determines the width of the habitable zone in space and time. Here a low-order model of weathering and climate, useful for gaining qualitative understanding, is developed to examine climate evolution for planets of various land-ocean fractions. It is pointed out that, if seafloor weathering does not depend directly on surface temperature, there can be no weathering-climate feedback on a waterworld. This would dramatically narrow the habitable zone of a waterworld. Results from our model indicate that weathering behavior does not depend strongly on land fraction for partially ocean-covered planets. This is powerful because it suggests that previous habitable zone theory is robust to changes in land fraction, as long as there is some land. Finally, a mechanism is proposed for a waterworld to prevent complete water loss during a moist greenhouse through rapid weathering of exposed continents. This process is named a 'waterworld self-arrest', and it implies that waterworlds can go through a moist greenhouse stage and end up as planets like Earth with partial ocean coverage. This work stresses the importance of surface and geologic effects, in addition to the usual incident stellar flux, for habitability.

  7. Mercury's Weather-Beaten Surface: Understanding Mercury in the Context of Lunar and Asteroidal Space Weathering Studies

    NASA Technical Reports Server (NTRS)

    Domingue, Deborah L.; Chapman, Clark. R.; Killen, Rosemary M.; Zurbuchen, Thomas H.; Gilbert, Jason A.; Sarantos, Menelaos; Benna, Mehdi; Slavin, James A.; Schriver, David; Travnicek, Pavel M.; Orlando, Thomas M.; Sprague, Ann L.; Blewett, David T.; Gillis-Davis, Jeffrey J.; Feldman, William C.; Lawrence, David J.; Ho, George C.; Ebel, Denton S.; Nittler, Larry R.; Vilas, Faith; Pieters, Carle M.; Solomon, Sean C.; Johnson, Catherine L.; Winslow, Reka M..; Helbert, Jorn; Peplowski, Patrick N.; Weider, Shoshana Z.; Mouawad, Nelly; Izenberg, Noam R.; McClintock, William E.

    2014-01-01

    Mercury's regolith, derived from the crustal bedrock, has been altered by a set of space weathering processes. Before we can interpret crustal composition, it is necessary to understand the nature of these surface alterations. The processes that space weather the surface are the same as those that form Mercury's exosphere (micrometeoroid flux and solar wind interactions) and are moderated by the local space environment and the presence of a global magnetic field. To comprehend how space weathering acts on Mercury's regolith, an understanding is needed of how contributing processes act as an interactive system. As no direct information (e.g., from returned samples) is available about how the system of space weathering affects Mercury's regolith, we use as a basis for comparison the current understanding of these same processes on lunar and asteroidal regoliths as well as laboratory simulations. These comparisons suggest that Mercury's regolith is overturned more frequently (though the characteristic surface time for a grain is unknown even relative to the lunar case), more than an order of magnitude more melt and vapor per unit time and unit area is produced by impact processes than on the Moon (creating a higher glass content via grain coatings and agglutinates), the degree of surface irradiation is comparable to or greater than that on the Moon, and photon irradiation is up to an order of magnitude greater (creating amorphous grain rims, chemically reducing the upper layers of grains to produce nanometer scale particles of metallic iron, and depleting surface grains in volatile elements and alkali metals). The processes that chemically reduce the surface and produce nanometer-scale particles on Mercury are suggested to be more effective than similar processes on the Moon. Estimated abundances of nanometer-scale particles can account for Mercury's dark surface relative to that of the Moon without requiring macroscopic grains of opaque minerals. The presence of nanometer-scale particles may also account for Mercury's relatively featureless visible-near-infrared reflectance spectra. Characteristics of material returned from asteroid 25143 Itokawa demonstrate that this nanometer-scale material need not be pure iron, raising the possibility that the nanometer-scale material on Mercury may have a composition different from iron metal [such as (Fe,Mg)S]. The expected depletion of volatiles and particularly alkali metals from solar-wind interaction processes are inconsistent with the detection of sodium, potassium, and sulfur within the regolith. One plausible explanation invokes a larger fine fraction (grain size less than 45 micron) and more radiation-damaged grains than in the lunar surface material to create a regolith that is a more efficient reservoir for these volatiles. By this view the volatile elements detected are present not only within the grain structures, but also as adsorbates within the regolith and deposits on the surfaces of the regolith grains. The comparisons with findings from the Moon and asteroids provide a basis for predicting how compositional modifications induced by space weathering have affected Mercury's surface composition.

  8. Mercury's Weather-Beaten Surface: Understanding Mercury in the Context of Lunar and Asteroidal Space Weathering Studies

    NASA Astrophysics Data System (ADS)

    Domingue, Deborah L.; Chapman, Clark R.; Killen, Rosemary M.; Zurbuchen, Thomas H.; Gilbert, Jason A.; Sarantos, Menelaos; Benna, Mehdi; Slavin, James A.; Schriver, David; Trávní?ek, Pavel M.; Orlando, Thomas M.; Sprague, Ann L.; Blewett, David T.; Gillis-Davis, Jeffrey J.; Feldman, William C.; Lawrence, David J.; Ho, George C.; Ebel, Denton S.; Nittler, Larry R.; Vilas, Faith; Pieters, Carle M.; Solomon, Sean C.; Johnson, Catherine L.; Winslow, Reka M.; Helbert, Jörn; Peplowski, Patrick N.; Weider, Shoshana Z.; Mouawad, Nelly; Izenberg, Noam R.; McClintock, William E.

    2014-05-01

    Mercury's regolith, derived from the crustal bedrock, has been altered by a set of space weathering processes. Before we can interpret crustal composition, it is necessary to understand the nature of these surface alterations. The processes that space weather the surface are the same as those that form Mercury's exosphere (micrometeoroid flux and solar wind interactions) and are moderated by the local space environment and the presence of a global magnetic field. To comprehend how space weathering acts on Mercury's regolith, an understanding is needed of how contributing processes act as an interactive system. As no direct information (e.g., from returned samples) is available about how the system of space weathering affects Mercury's regolith, we use as a basis for comparison the current understanding of these same processes on lunar and asteroidal regoliths as well as laboratory simulations. These comparisons suggest that Mercury's regolith is overturned more frequently (though the characteristic surface time for a grain is unknown even relative to the lunar case), more than an order of magnitude more melt and vapor per unit time and unit area is produced by impact processes than on the Moon (creating a higher glass content via grain coatings and agglutinates), the degree of surface irradiation is comparable to or greater than that on the Moon, and photon irradiation is up to an order of magnitude greater (creating amorphous grain rims, chemically reducing the upper layers of grains to produce nanometer scale particles of metallic iron, and depleting surface grains in volatile elements and alkali metals). The processes that chemically reduce the surface and produce nanometer-scale particles on Mercury are suggested to be more effective than similar processes on the Moon. Estimated abundances of nanometer-scale particles can account for Mercury's dark surface relative to that of the Moon without requiring macroscopic grains of opaque minerals. The presence of nanometer-scale particles may also account for Mercury's relatively featureless visible-near-infrared reflectance spectra. Characteristics of material returned from asteroid 25143 Itokawa demonstrate that this nanometer-scale material need not be pure iron, raising the possibility that the nanometer-scale material on Mercury may have a composition different from iron metal [such as (Fe,Mg)S]. The expected depletion of volatiles and particularly alkali metals from solar-wind interaction processes are inconsistent with the detection of sodium, potassium, and sulfur within the regolith. One plausible explanation invokes a larger fine fraction (grain size <45 ?m) and more radiation-damaged grains than in the lunar surface material to create a regolith that is a more efficient reservoir for these volatiles. By this view the volatile elements detected are present not only within the grain structures, but also as adsorbates within the regolith and deposits on the surfaces of the regolith grains. The comparisons with findings from the Moon and asteroids provide a basis for predicting how compositional modifications induced by space weathering have affected Mercury's surface composition.

  9. Space weathered rims found on the surfaces of the Itokawa dust particles

    NASA Astrophysics Data System (ADS)

    Noguchi, Takaaki; Kimura, Makoto; Hashimoto, Takahito; Konno, Mitsuru; Nakamura, Tomoki; Zolensky, Michael E.; Okazaki, Ryuji; Tanaka, Masahiko; Tsuchiyama, Akira; Nakato, Aiko; Ogami, Toshinori; Ishida, Hatsumi; Sagae, Ryosuke; Tsujimoto, Shinichi; Matsumoto, Toru; Matsuno, Junya; Fujimura, Akio; Abe, Masanao; Yada, Toru; Mukai, Toshifumi; Ueno, Munetaka; Okada, Tatsuaki; Shirai, Kei; Ishibashi, Yukihiro

    2014-02-01

    On the basis of observations using Cs-corrected STEM, we identified three types of surface modification probably formed by space weathering on the surfaces of Itokawa particles. They are (1) redeposition rims (2-3 nm), (2) composite rims (30-60 nm), and (3) composite vesicular rims (60-80 nm). These rims are characterized by a combination of three zones. Zone I occupies the outermost part of the surface modification, which contains elements that are not included in the unchanged substrate minerals, suggesting that this zone is composed of sputter deposits and/or impact vapor deposits originating from the surrounding minerals. Redeposition rims are composed only of Zone I and directly attaches to the unchanged minerals (Zone III). Zone I of composite and composite vesicular rims often contains nanophase (Fe,Mg)S. The composite rims and the composite vesicular rims have a two-layered structure: a combination of Zone I and Zone II, below which Zone III exists. Zone II is the partially amorphized zone. Zone II of ferromagnesian silicates contains abundant nanophase Fe. Radiation-induced segregation and in situ reduction are the most plausible mechanisms to form nanophase Fe in Zone II. Their lattice fringes indicate that they contain metallic iron, which probably causes the reddening of the reflectance spectra of Itokawa. Zone II of the composite vesicular rims contains vesicles. The vesicles in Zone II were probably formed by segregation of solar wind He implanted in this zone. The textures strongly suggest that solar wind irradiation damage and implantation are the major causes of surface modification and space weathering on Itokawa.

  10. Observation of Discrete Surface Solitons

    Microsoft Academic Search

    S. Suntsov; K. G. Makris; D. N. Christodoulides; G. I. Stegeman; A. Haché; R. Morandotti; H. Yang; G. Salamo; M. Sorel

    2006-01-01

    We report the first observation of discrete optical surface solitons at the interface between a nonlinear self-focusing waveguide lattice and a continuous medium. The effect of power on the localization process of these optical self-trapped states at the edge of an AlGaAs waveguide array is investigated in detail. Our experimental results are in good agreement with theoretical predictions.

  11. Analysis of fog occurrence on E11-A75 Motorway, with weather station data in relation to satellite observation

    NASA Astrophysics Data System (ADS)

    Colomb, M.; Bernardin, F.; Favier, B.; Mallet, E.; Laurantin, O.

    2010-07-01

    Transport is often disturbed in wintertime by fog occurrence causing delay. Fog may also be responsible for dramatic accidents causing injuries and fatalities. For meteorological weather services, fog is defined as when visibility is less than 1000 m. However, for road traffic, when visibility becomes less than 200 m, fog is considered a traffic hazard for road transport. Fog forecast remains a difficult task. Satellite observation combined with surface measurements by a network of road weather stations can provide short-term information that could be useful to assist traffic authorities in taking decisions relating to traffic control measures or drivers information. Satellite images allow to identify cloud types and to establish a map of the risk of fog occurrence. The surface measurements help to discriminate between low clouds and fog. The analysis method has already been tested last winter on some case studies on the motorway E11-A75 in Auvergne region in France, thanks to a network of 15 weather stations along the 300 km of motorway. In the highest area that is between 580 and 1100 m, the value of the relative humidity has been analysed in relation to the visibility measured by a diffusiometer and the observations of road maintenance staff. The main results will be presented and connected to the traditional synoptic network of Météo-France. In order to improve the map of fog risks, the requirement to have relevant data has been pointed out, especially for the relative humidity near the ground surface (i.e. 2 m above the ground). To go further in this investigation, one weather station, at the Col de la Fageole, has been identified as having the greatest occurrence of dense fog, i.e. less than 200 m. Then it has been decided to enrich the instrumentation at this observation point later on with a present weather sensor and with a camera. This paper will focus on the physical data of the weather station. It will be examined how the additional data of the new sensor, the meteorological visibility and the discrimination of the nature of precipitation will help to improve the analysis.

  12. Widespread Surface Weathering on Early Mars: possible implication on the Past Climate

    NASA Astrophysics Data System (ADS)

    Loizeau, Damien; Carter, John; Mangold, Nicolas; Poulet, François; Rossi, Angelo P.; Allemand, Pascal; Lozac'h, Loïc; Quantin, Cathy; Bibring, Jean-Pierre

    2015-04-01

    The recent discovery of widespread hydrous clays on Mars with OMEGA/Mars Express and CRISM/MRO indicates that diverse and widespread aqueous environments existed on Mars, from the surface to kilometric depths [1, 2]. The study of the past habitability and past climates of the planet requires assessing the importance of sustained surface water vs. subsurface water in its aqueous history. Vertical sequences of Al-rich clays on top of Fe/Mg-rich clays in the top tens of meters of the surface are identified on Mars [3-6] (see figure 1) and interpreted as possible weathering profiles, similar to cases of pedogenesis on Earth (e.g. [7, 8]). A global study of these clay sequences has recently been published by Carter et al. [9]. This following work presents detailed geological analysis, performed for each identified candidate, in order to constrain their age and origin. With the increasing availability of CTX and HiRISE stereoimages, we investigate the thickness of the altered sequences, the age of the altered units and the different geological contexts to further understand the weathering process(es), and their possible implication on the past climate. The types of geologic settings where the interpreted weathering profiles are observed are much varied: from basin floor to plateaus, in apparent massive rocks to finely layered rocks. Besides, the number and variety of sequences is/was likely larger. However, in term of chronology, the alteration seems to have stopped in a relatively limited period of time for the studied cases, between 3.8 and 3.6 Ga. This would point to a formation due to a global process that enabled liquid water at the surface and pedogenesis in various regions, on various terrains, from late Noachian to early Hesperian. This global process would imply regular, widely distributed ice or precipitations in large regions of Mars at that time. If weathering occurred before that time, during the early or middle Noachian, the sequences may have been erased by the more intense erosion of that time. Also, it is difficult to date older terrains by crater counting on small surfaces. These observations make a strong constrain concerning the past habitability of Mars: liquid water has been widely available at the surface of the planet, in contact with different rocks, until the early Hesperian time. Acknowledgment: Some of the authors have received funding from the ERC (FP7/2007-2013)/ERC Grant agreement n° 280168. References: [1] Ehlmann B., et al. Nature, 479, 53-60 (2011). [2] Carter J., et al. JGR, 118, 831-858 (2013) [3] Gaudin A., et al. Icarus, 216(1), 257-268 (2011). [4] Loizeau D., et al. Icarus, 205, 396-418 (2010). [5] Noe Dobrea E., et al. JGR, 115, E00D19 (2010). [6] Le Deit L., et al. JGR, 117, E00J05 (2012). [7] Velde B., et al. Ed. Springer, Berlin, (1995). [8] Wilson M. Clay Minerals, 39, 233-266 (2004). [9] Carter J., et al. Icarus, 248, 373-382.

  13. Site-specific analog weather-forecast system for northwest Himalaya, India

    Microsoft Academic Search

    Dan Singh; Amreek Singh; Ashwagosha Ganju

    2008-01-01

    In an analog weather-forecasting procedure, recorded weather in the past analogs corresponding to the current weather situation is used to predict future weather. Consistent with the procedure, a theoretical framework is developed to predict weather at a specific site in the Pir Panjal range of the northwest Himalaya, India, using surface weather observations of the past ten winters (1991\\/92 to

  14. The Trajectory of Giant Iceberg B15a: Preliminary Observations using GPS and Automatic Weather Stations

    Microsoft Academic Search

    D. R. MacAyeal; J. Thom; A. Bliss; G. Weidner; B. D. Kerman; M. Lazzara; C. R. Stearns

    2001-01-01

    In January 2001, three automatic weather and GPS monitoring stations were deployed on the 150 by 50 km iceberg known as B15a. These stations relay GPS coordinates and surface wind measurements on an hourly basis through the ARGOS satellite relay system. The intended purpose of these measurements is to provide information that is superior to that available from tracking the

  15. Evaluation of “all weather” microwave-derived land surface temperatures with in situ CEOP measurements

    NASA Astrophysics Data System (ADS)

    Catherinot, J.; Prigent, C.; Maurer, R.; Papa, F.; JiméNez, C.; Aires, F.; Rossow, W. B.

    2011-12-01

    Land surface skin temperature Ts plays a key role in meteorological and climatological processes but the availability and the accuracy of Ts measurements over land are still limited, especially under cloudy conditions. Ts estimates from infrared satellite observations can only be derived under clear sky. Passive microwave measurements are much less affected by clouds and can provide Ts regardless of the cloud conditions. A neural network inversion including first guess information has been previously developed to retrieve Ts, along with atmospheric water vapor, cloud liquid water, and surface emissivities over land from Special Sensor Microwave/Imager measurements, with a spatial resolution of 0.25° × 0.25°, at least twice daily. In this study, Ts estimates are evaluated through careful comparisons with in situ measurements in different environments over a full annual cycle. Under clear sky conditions, the quality of our microwave neural network retrieval is equivalent to the infrared International Satellite Cloud Climatology Project products, for most in situ stations, with errors ˜3 K as compared to in situ measurements. The performance of the microwave algorithm is similar under clear and cloudy conditions, confirming the potential of the microwaves under clouds. The Ts accuracy does not depend upon the surface emissivity, as the variability of this parameter is accounted for in the processing. Our microwave Ts have been calculated for more than 15 years (1993 to mid-2008). These "all weather" Ts are a very valuable complement to the IR-derived Ts, for use in atmospheric and surface models.

  16. Feasibility of using a seismic surface wave method to study seasonal and weather effects on shallow surface soils

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objective of the paper is to study the temporal variations of the subsurface soil properties due to seasonal and weather effects using a combination of a new seismic surface method and an existing acoustic probe system. A laser Doppler vibrometer (LDV) based multi-channel analysis of surface wav...

  17. Characterization of surface carbon films on weathered Japaneseroof tiles by soft x-ray spectroscopy

    SciTech Connect

    Muramatsu, Y.; Yamashita, M.; Motoyama, M.; Hirose, M.; Denlinger, J.D.; Gullikson, E.M.; Perera, R.C.

    2004-07-15

    The effects of weathering on carbon films deposited onJapanese smoked roof tileswere investigated by soft x-ray absorption andemission spectroscopy using synchrotron radiation. X-ray absorptionmeasurements revealed that weathering oxidizes the carbon films and thatpartial carboxy chemical bonding occurs. Incident angle-dependent x-rayabsorption spectra in the C K region confirmed that the degree of theorientation at the surface of the oxidized carbon films decreases withweathering. However, the take-off angle-dependent C K x-ray emissionspectra showed that the orientation of the layered carbon structure ismaintained in the bulk portion when weathered. Therefore, it is confirmedthat oxidation proceeds from the surface of the carbon films. Weatheringdegrades and oxidizes the surface carbon films, which causes the metallicsilver color to change to darker gray.

  18. Observations of Coronal Mass Ejections from the Solar Mass Ejection Imager and Space Weather Implications

    Microsoft Academic Search

    Janet C. Johnston; David F. Webb; Ghee Fry; Joel B. Mozer; Thomas A. Kuchar; Donald R. Mizuno; Timothy A. Howard

    2006-01-01

    The Solar Mass Ejection Imager (SMEI) was launched into a Sun-synchronous orbit in January 2003. Its mission objective is to detect and track coronal mass ejections (CMEs) from the Sun in order to improve space weather forecasts. In the three years since launch, over 200 CMEs, about 30 of which were Earth-directed, have been observed by SMEI. We have been

  19. Weathering pits as indicators of the relative age of granite surfaces in the Cairngorm mountains, Scotland

    USGS Publications Warehouse

    Hall, A.M.; Phillips, W.M.

    2006-01-01

    Weathering pits 1-140 cm deep occur on granite surfaces in the Cairngorms associated with a range of landforms, including tors, glacially exposed slabs, large erratics and blockfields. Pit depth is positively correlated with cosmogenic exposure age, and both measures show consistent relationships on individual rock landforms. Rates of pit deepening are non-linear and a best fit is provided by the sigmoidal function D = b1+ exp(b2+b3/t). The deepest pits occur on unmodified tor summits, where 10 Be exposure ages indicate that surfaces have been exposed to weathering for a minimum of 52-297 ka. Glacially exposed surfaces with pits 10-46 cm deep have given 10 Be exposure durations of 21-79 ka, indicating exposure by glacial erosion before the last glacial cycle. The combination of cosmogenic exposure ages with weathering pit depths greatly extends the area over which inferences can be made regarding the ages of granite surfaces in the Cairngorms. Well-developed weathering pits on glacially exposed surfaces in other granite areas are potential indicators of glacial erosion before the Last Glacial Maximum. ?? Swedish Society for Anthropology and Geography.

  20. Hubble Observes Surface of Titan

    NASA Technical Reports Server (NTRS)

    1994-01-01

    Scientists for the first time have made images of the surface of Saturn's giant, haze-shrouded moon, Titan. They mapped light and dark features over the surface of the satellite during nearly a complete 16-day rotation. One prominent bright area they discovered is a surface feature 2,500 miles across, about the size of the continent of Australia.

    Titan, larger than Mercury and slightly smaller than Mars, is the only body in the solar system, other than Earth, that may have oceans and rainfall on its surface, albeit oceans and rain of ethane-methane rather than water. Scientists suspect that Titan's present environment -- although colder than minus 289 degrees Fahrenheit, so cold that water ice would be as hard as granite -- might be similar to that on Earth billions of years ago, before life began pumping oxygen into the atmosphere.

    Peter H. Smith of the University of Arizona Lunar and Planetary Laboratory and his team took the images with the Hubble Space Telescope during 14 observing runs between Oct. 4 - 18. Smith announced the team's first results last week at the 26th annual meeting of the American Astronomical Society Division for Planetary Sciences in Bethesda, Md. Co-investigators on the team are Mark Lemmon, a doctoral candidate with the UA Lunar and Planetary Laboratory; John Caldwell of York University, Canada; Larry Sromovsky of the University of Wisconsin; and Michael Allison of the Goddard Institute for Space Studies, New York City.

    Titan's atmosphere, about four times as dense as Earth's atmosphere, is primarily nitrogen laced with such poisonous substances as methane and ethane. This thick, orange, hydrocarbon haze was impenetrable to cameras aboard the Pioneer and Voyager spacecraft that flew by the Saturn system in the late 1970s and early 1980s. The haze is formed as methane in the atmosphere is destroyed by sunlight. The hydrocarbons produced by this methane destruction form a smog similar to that found over large cities, but is much thicker.

    Smith's group used the Hubble Space Telescope's WideField/Planetary Camera 2 at near-infrared wavelengths (between .85 and 1.05 microns). Titan's haze is transparent enough in this wavelength range to allow mapping of surface features according to their reflectivity. Only Titan's polar regions could not be mapped this way, due to the telescope's viewing angle of the poles and the thick haze near the edge of the disk. Their image-resolution (that is, the smallest distance seen in detail) with the WFPC2 at the near-infrared wavelength is 360 miles. The 14 images processed and compiled into the Titan surface map were as 'noise' free, or as free of signal interference, as the space telescope allows, Smith said.

    Titan makes one complete orbit around Saturn in 16 days, roughly the duration of the imaging project. Scientists have suspected that Titan's rotation also takes 16 days, so that the same hemisphere of Titan always faces Saturn, just as the same hemisphere of the Earth's moon always faces the Earth. Recent observations by Lemmon and colleagues at the University of Arizona confirm this true.

    It's too soon to conclude much about what the dark and bright areas in the Hubble Space Telescope images are -- continents, oceans, impact craters or other features, Smith said. Scientists have long suspected that Titan's surface was covered with a global ehtane-methane ocean. The new images show that there is at least some solid surface.

    Smith's team made a total 50 images of Titan last month in their program, a project to search for small scale features in Titan's lower atmosphere and surface. They have yet to analyze images for information about Titan's clouds and winds. That analysis could help explain if the bright areas are major impact craters in the frozen water ice-and-rock or higher-altitude features.

    The images are important information for the Cassini mission, which is to launch a robotic spacecraft on a 7-year journey to Saturn in October 1997. About three weeks before Cassini's first flyby

  1. Assimilation of surface AWS using 3DVAR and LAPS and their effects on short-term high-resolution weather forecasts

    NASA Astrophysics Data System (ADS)

    Barcons, Jordi; Folch, Arnau; Sairouní, Abdelmalik; Miró, Josep Ramon

    2014-05-01

    The progress in Data Assimilation (DA) techniques that incorporate surface weather observations into high-resolution Numerical Weather Prediction (NWP) models remains a challenging problem because of handling surface data in the presence of terrain misrepresentation and balance approximation. In the framework of NWP and its operational applications, this study presents a comparison between two data assimilation systems using conventional observational data from surface Automatic Weather Stations (AWS): the three-dimensional variational analysis (3DVAR) and the Local Analysis and Prediction System (LAPS). We study the ability of these two systems to assimilate data from surface AWS and assess which one performs better for near-surface wind and temperature fields to initialize a short-range 1-km resolution forecast with the Weather Research and Forecasting (WRF) model. Results show that the 3DVAR assimilation patterns are unrealistic given the inhomogeneous nature of the near-surface fields. In contrast, LAPS analyses without applying a balance routine show an heterogeneous assimilation pattern accounting for the complexity of the terrain. In addition, LAPS produces fields much more consistent with the observations than those of the 3DVAR method. During the model spin-up period, simulations initialized by both DA methods approached rapidly the control simulation without DA. However, 1 km resolution simulations initialized with LAPS analyses exhibit a significant improvement for the wind module forecast.

  2. The Global Weather Experiment1. The Observational Phase Through the First Special Observing Period

    Microsoft Academic Search

    R. J. Fleming; T. M. Kaneshige; W. E. McGovern

    1979-01-01

    An unprecedented analysis of the atmosphere of planet Earth is currently underway with the involvement of over 140 countries in the Global Weather Experiment-the largest international scientific experiment yet attempted. After many years of planning, the Operational Year began in December of 1978. Following the field phase and data management phase, a multi-year evaluation and research program will commence and

  3. THE LINK BETWEEN CLAY MINERAL WEATHERING AND THE FORMATION OF NI SURFACE PRECIPITATES

    E-print Network

    Sparks, Donald L.

    THE LINK BETWEEN CLAY MINERAL WEATHERING AND THE FORMATION OF NI SURFACE PRECIPITATES Andreas C, Schlieren, Switzerland Spectroscopic and microscopic studies have shown that Ni and Co sorption by clay:1 or 2:1 phyllosilicates requires the release ofA1 and Si from clay minerals. Due to similar metal

  4. Chemical Weathering of Black Shales and Rare Earth Element Composition of Surface Waters and Groundwater

    NASA Astrophysics Data System (ADS)

    Hannigan, R. E.; Johannesson, K. H.

    2001-05-01

    Weathering processes dominate the dissolved and suspended loads of most of the world's major rivers. Among sedimentary rocks, black shales are particularly sensitive to chemical weathering. Therefore, shale systems are useful for investigating the partitioning of chemical elements during chemical weathering. Recent studies, such as those by Peucker-Ehrenbrink, Ravizza and others, link chemical weathering of black shales to changes in marine isotopic composition. Rare earth elements (REE) have a unique chemistry and are ideal for such tracer studies. We explored the effect of modern chemical weathering of black shales on the hydrochemistry of surface and groundwaters in the Mohawk Valley of New York State. This region provides an ideal site for the investigation of trace element remobilization during the chemical weathering of black shales. In this region, surface and groundwaters, in intimate contact with black shales and have high dissolved metal concentrations presumably due to water-rock interactions. The extent to which the dissolved REE composition of the surface and ground waters retains the rock signature is, in someway related to the length of time that the water remains in contact with the rock. We compared the REE compositions of surface and groundwaters in areas draining black shale to those of waters draining regions of dolostone-limestone to explore the extent of metal release due to chemical weathering. Shale normalized REE patterns for stream waters exhibit slight heavy REE enrichments and, at some locations, LREE depletion. REE patterns of the waters normalized to their respective sediments show some LREE depletion. However, waters associated with the Little Falls dolomite show fractionation predominantly enriched in the heavy REEs. Differences between the black shale sites, recorded as light REE depletion and/or middle REE enrichment, may be related to the discharge of the streams and the total dissolved solids. The dissolved REE chemistry of rivers draining the limestone-dolostone facies to the north and west of the black shale facies is dominated by the Ln-carbonate species. REE speciation in the black shale sites when compared to the dolomitic sites show interesting features. For example, the "dolomite" lake exhibits a significant amount of free metal species as well as lanthanide-fluoride complexation. Our preliminary results indicate that the surface and groundwaters discretely record metal release from black shales. These data lend further credence to the hypothesis that black shale weathering may significantly contribute to the ocean metal budget.

  5. Estimates of Surface Fluxes from Global Operational Numerical Weather Predictions

    Microsoft Academic Search

    D. Burridge; A. Gilchrist

    1989-01-01

    The success of coupled models of the ocean--atmosphere system depends in part on their ability to estimate the momentum, heat and water vapour fluxes at the interface accurately. Their accuracy as now calculated by atmospheric numerical forecast models with relevant variables at the sea surface given is uncertain. The achievement of an acceptable accuracy in this simpler situation is an

  6. ULF Waves Observed at MAGDAS Stations as Probes for Litho-Space Weather Study

    NASA Astrophysics Data System (ADS)

    Yumoto, Kiyohumi

    K.Yumoto, Space Environment Research Center (SERC), Kyushu University started the MAGDAS Project effectively in May of 2005, with the installation of the first unit in Hualien, Taiwan (Yumoto et al., 2006, 2007). Since then, over 50 units have been deployed around the world. They are concentrated along three chains: (1) North and South of Japan (the so-called "210o Magnetic Meridian Chain"), (2) Dip Equator Chain, and (3) Africa Chain (the so-called "96o Magnetic Meridian Chain"). The main goals of MAGDAS project are: (1) study magnetospheric pro-cesses by distinguishing between temporal changes and spatial variations in the phenomena, (2) clarify global structures and propagation characteristics of magnetospheric variations from higher to equatorial latitudes, and (3) understand global generation mechanisms of the Solar-Terrestrial phenomena (see Yumoto, 2004). From MAGDAS observations, ULF waves are found to be used as good probes for litho-space weather study in developing and developed countries. In the present paper, we will introduce the following examples: Pc 5 magnetic amplitudes at lower-latitude MAGDAS station show a linear relation with the solar wind velocity, thus we can use the Pc 5 amplitudes as a monitoring probe of the solar wind velocity. Pc 3-4 magnetic pulsations have skin depth comparable with the depth of epicentre of earthquakes in the lithosphere. Therefore, we can use Pc 3-4 as a probe for detecting ULF anomaly and precursors associated with great earthquakes. Pi 2 magnetic pulsations are observed globally at MAGDAS stations located at high, middle, low, and equatorial latitudes in night-and day-time. We can use the Pi 2s as a good indicator of onsets of magnetospheric substorms. Sudden commencements (sc), sudden impulse (si), and solar flare effects (sfe) create magnetic variations at MAGDAS stations. Therefore, MAGDAS data can be used as a probe of interplanetary shocks and interplanetary discontinuities in the solar wind, and solar flare on the solar surface, respectively.

  7. Stratospheric influence on tropospheric jet streams, storm tracks and surface weather

    NASA Astrophysics Data System (ADS)

    Kidston, Joseph; Scaife, Adam A.; Hardiman, Steven C.; Mitchell, Daniel M.; Butchart, Neal; Baldwin, Mark P.; Gray, Lesley J.

    2015-06-01

    A powerful influence on the weather that we experience on the ground can be exerted by the stratosphere. This highly stratified layer of Earth's atmosphere is found 10 to 50 kilometres above the surface and therefore above the weather systems that develop in the troposphere, the lowest layer of the atmosphere. The troposphere is dynamically coupled to fluctuations in the speed of the circumpolar westerly jet that forms in the winter stratosphere: a strengthening circumpolar jet causes a poleward shift in the storm tracks and tropospheric jet stream, whereas a weakening jet causes a shift towards the equator. Following a weakening of the stratospheric jet, impacts on the surface weather include a higher likelihood of extremely low temperature over northern Europe and the eastern USA. Eddy feedbacks in the troposphere amplify the surface impacts, but the mechanisms underlying these dynamics are not fully understood. The same dynamical relationships act at very different timescales, ranging from daily variations to longer-term climate trends, suggesting a single unifying mechanism across timescales. Ultimately, an improved understanding of the dynamical links between the stratosphere and troposphere is expected to lead to improved confidence in both long-range weather forecasts and climate change projections.

  8. Landscape Dissection in the Alakai Swamp on Kauai by Groundwater Enhanced Weathering and and Surface Water

    NASA Astrophysics Data System (ADS)

    Pederson, D. T.; Knapp, E.; Blay, C.; Gates, J. B.

    2011-12-01

    The Alakai Swamp lies on the high western-side of the shield volcano that created Kauai some 5 million years ago. The swamp itself rests on younger lower-gradient lava flows. The basalts are of mantle origin and usually weather rapidly and directly to clays on the island. The remnants of the high points of the shield volcano form a natural "rain making" geometry (with the trade winds) such that the highest points of the Alakai Swamp near the summit experience rainfalls around 1500 mm/yr tapering off to approximately 250 mm/yr in the lower northwestern part of the swamp. Frequent dense fogs also represent a source of moisture for plant growth. The surface of the swamp approximates a sloping plane surface dissected by headward advancing tributaries of the deeply incised Waimea Canyon. Areas of bog/swamps and dense taller vegetation are located in the headwaters and divide areas of tributaries. The bog/swamp areas have a pronounced dip parallel to the general paths of the incising tributaries and represent the local surface of saturation of a zone of chemical and organic reactions weathering (etching) the underlying basalts. Away from the bogs/swamps vegetation height is greater reflecting opportunities for greater root development. Headwaters areas of the tributaries are small with tributary discharge curves during rainfall events suggesting significant groundwater contributions. The tributary canyons are very steep-sided and wide in the lower reaches resulting in very narrow drainage divides. The steep canyon walls are a result of high weathering rates associated with vegetation growth enhanced by groundwater discharge. The rapid growth of roots is also very effective in breaking up rock creating additional surface areas for weathering which increases the rate of conversion of basalts to clay. There is a rapid narrowing of tributary canyons upstream, in places to notch canyons, which further supports the contention that groundwater supported weathering processes are important in landscape dissection.

  9. Observation from space of meteorological fields at the scale of regional Numerical Weather Forecast models

    Microsoft Academic Search

    G. Perona; R. Notarpietro; M. Gabella; A. Speranza

    2003-01-01

    In this paper we report the results of feasibility studies concerning the use of radars on polar orbiting space-platforms for the direct observation of meteorological fields (in particular large-scale vertical velocity) that are crucial in the initialisation and verification of models for NWF (Numerical Weather Forecast). Specifically, we have made reference to LAM (Limited Area Models) with horizontal grid-size of

  10. Effects of UV weathering on surface properties of polypropylene composites reinforced with wood flour, lignin, and cellulose

    NASA Astrophysics Data System (ADS)

    Peng, Yao; Liu, Ru; Cao, Jinzhen; Chen, Yu

    2014-10-01

    In this study, the influence of accelerated weathering on polypropylene composites reinforced with wood flour (WF), lignin, and cellulose at different loading levels were evaluated. Six groups of samples were exposed in a QUV accelerated weathering tester for a total of 960 h. The surface color, surface gloss, contact angle and flexural properties of the samples were tested. Besides, the weathered surface was characterized by SEM and ATR-FTIR. The results revealed that (1) the discoloration of composites was accelerated by the presence of lignin, especially at high content; (2) composites containing lignin showed less loss of flexural strength and modulus, less cracks, and better hydrophobicity on weathered surface than other groups, confirming its functions of stabilization and antioxidation; (3) cellulose-based composites exhibited better color stability but more significant deterioration in flexural properties after weathering compared to other composites, suggesting that such kind of composites could not be used as load-bearing structure in outdoor applications.

  11. Low Cloud Type over the Ocean from Surface Observations. Part I: Relationship to Surface Meteorology and the Vertical Distribution of Temperature and Moisture

    Microsoft Academic Search

    Joel R. Norris

    1998-01-01

    Surface cloud observations and coincident surface meteorological observations and soundings from five ocean weather stations are used to establish representative relationships between low cloud type and marine boundary layer (MBL) properties for the subtropics and midlatitudes by compositing soundings and meteorological ob- servations for which the same low cloud type was observed. Physically consistent relationships are found to exist between

  12. WORLD SURFACE CURRENTS FROM SHIP'S DRIFT OBSERVATIONS

    SciTech Connect

    Duncan, C.P.; Schladow, S.G.

    1980-11-01

    Over 4 million observations of ship's drift are on file at the U.S. National Oceanographic Data Centre, in Washington, D. C., representing a vast amount of information on ocean surface currents. The observed drift speeds are dependent on the frequency of occurence of the particular current speeds and the frequency of observation. By comparing frequency of observation with the drift speeds observed it is possible to confirm known current patterns and detect singularities in surface currents.

  13. Space-weather Parameters for 1,000 Active Regions Observed by SDO/HMI

    NASA Astrophysics Data System (ADS)

    Bobra, M.; Liu, Y.; Hoeksema, J. T.; Sun, X.

    2013-12-01

    We present statistical studies of several space-weather parameters, derived from observations of the photospheric vector magnetic field by the Helioseismic and Magnetic Imager (HMI) aboard the Solar Dynamics Observatory, for a thousand active regions. Each active region has been observed every twelve minutes during the entirety of its disk passage. Some of these parameters, such as energy density and shear angle, indicate the deviation of the photospheric magnetic field from that of a potential field. Other parameters include flux, helicity, field gradients, polarity inversion line properties, and measures of complexity. We show that some of these parameters are useful for event prediction.

  14. Future space-based sounding observations for weather analysis and forecasting

    NASA Astrophysics Data System (ADS)

    Smith, W. L.

    1992-07-01

    During this decade, advanced satellite remote sounding technology will be implemented as part of the Earth Observing System (EOS) program. Included are high spectral resolution, continuous spectral coverage, thermodynamic sounding infrared spectrometers which will provide greatly improved vertical resolution and accuracy. Advanced cloud penetrating microwave radiometers and very high spatial resolution imaging radiometers will accompany the infrared sounder to optimize the product for forecast model initialization. A doppler lidar will fly aboard EOS satellites to provide for the first time global wind data. Characteristics of these new observing systems and their expected impact on the weather analysis/forecast operation are summarized.

  15. An assessment of numerical weather prediction (NWP) models surface soil temperature products using ground-based measurements

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Numerical weather prediction (NWP) models developed by various weather centers produce estimates of the soil temperature state. In this study in situ data collected over the state of Oklahoma is used to assess and compare three NWP surface (soil) temperature products. These are 1) the integrated for...

  16. Evaluating the Impacts of NASA/SPoRT Daily Greenness Vegetation Fraction on Land Surface Model and Numerical Weather Forecasts

    NASA Technical Reports Server (NTRS)

    Bell, Jordan R.; Case, Jonathan L.; Molthan, Andrew L.

    2011-01-01

    The NASA Short-term Prediction Research and Transition (SPoRT) Center develops new products and techniques that can be used in operational meteorology. The majority of these products are derived from NASA polar-orbiting satellite imagery from the Earth Observing System (EOS) platforms. One such product is a Greenness Vegetation Fraction (GVF) dataset, which is produced from Moderate Resolution Imaging Spectroradiometer (MODIS) data aboard the NASA EOS Aqua and Terra satellites. NASA SPoRT began generating daily real-time GVF composites at 1-km resolution over the Continental United States (CONUS) on 1 June 2010. The purpose of this study is to compare the National Centers for Environmental Prediction (NCEP) climatology GVF product (currently used in operational weather models) to the SPoRT-MODIS GVF during June to October 2010. The NASA Land Information System (LIS) was employed to study the impacts of the new SPoRT-MODIS GVF dataset on land surface models apart from a full numerical weather prediction (NWP) model. For the 2010 warm season, the SPoRT GVF in the western portion of the CONUS was generally higher than the NCEP climatology. The eastern CONUS GVF had variations both above and below the climatology during the period of study. These variations in GVF led to direct impacts on the rates of heating and evaporation from the land surface. The second phase of the project is to examine the impacts of the SPoRT GVF dataset on NWP using the Weather Research and Forecasting (WRF) model. Two separate WRF model simulations were made for individual severe weather case days using the NCEP GVF (control) and SPoRT GVF (experimental), with all other model parameters remaining the same. Based on the sensitivity results in these case studies, regions with higher GVF in the SPoRT model runs had higher evapotranspiration and lower direct surface heating, which typically resulted in lower (higher) predicted 2-m temperatures (2-m dewpoint temperatures). The opposite was true for areas with lower GVF in the SPoRT model runs. These differences in the heating and evaporation rates produced subtle yet quantifiable differences in the simulated convective precipitation systems for the selected severe weather case examined.

  17. The Mileura Widefield Array: Application To Heliospheric Observations and Space Weather

    NASA Astrophysics Data System (ADS)

    Salah, J. E.; Lonsdale, C. J.; Oberoi, D.; Kasper, J. C.; Lazarus, A. J.

    2004-12-01

    Radio arrays with hundreds of distributed antenna elements have recently become possible due to advances in digital information technology including high speed signal processing and wideband data transport. This paper presents the design of an array operating at frequencies below 300 MHz whose goal is to improve the sensitivity and resolution of astronomical and heliospheric observations. A demonstrator system for this array is now being planned for deployment at the Mileura Station in Western Australia, where the RFI environment is ideally suited for such low frequency observations. The potential of such an array for heliospheric and space weather observations has been studied using two techniques, namely interplanetary scintillations and Faraday rotation. Both techniques depend on observing the emission from astronomical radio sources as they are occulted by a coronal mass ejection traveling in the solar wind. The measurements will allow a determination of the density and velocity of the CME, as well as its magnetic field strength and orientation. In addition, the array can be used to measure variations in the Earth's ionosphere on very small scales within the field-of-view. This paper summarizes the array design and capabilities, outlines the planned demonstrator system at Mileura, and illustrates the expected heliospheric observations using simulations of recent space weather events.

  18. On the sensitivity of numerical weather prediction to remotely sensed marine surface wind data: A simulation study

    NASA Astrophysics Data System (ADS)

    Cane, Mark A.; Cardone, Vincent J.; Halem, Milton; Halberstam, Isidore

    1981-09-01

    A series of observing system simulation experiments has been performed to assess the potential impact of marine surface wind data on numerical weather prediction. Care was taken to duplicate the spatial coverage and error characteristics of conventional surface, radiosonde, ship, and aircraft reports. These observations, suitably degraded to account for instrument and sampling errors, were used in a conventional analysis-forecast cycle. A series of five 72-hour forecasts were then made by using the analyzed fields as initial conditions. The forecast error growth was found to be similar to that in operational numerical forecasts. Further experiments simulated the time-continuous assimilation of remotely sensed marine surface wind or temperature sounding data in addition to the conventional data. The wind data were fabricated directly for model grid points intercepted by a Seasat-1 scatterometer (SASS) swath and were placed in the lowest active level (945 mbar) of the model. The temperature sounding experiment assimilated error-free data fabricated along actual Nimbus orbits. Forecasts were made from the resulting analysis fields, and the impact of the simulated satellite data was assessed by comparing these forecast errors with those of the control forecasts. When error-free winds were assimilated by using a localized successive correction method (SCM), the impacts in extratropical regions proved to be substantial, especially in lower tropospheric quantities such as surface pressure. In contrast, a less sophisticated assimilation method resulted in negligible impact. The assimilation of error-free sounder data (again by the SCM) gave impacts comparable to the wind data, suggesting that surface wind data alone may be as valuable as temperature soundings for numerical weather prediction. The effects of nominal SASS errors (±2 m/s in magnitude, ±20° in direction) on the impacts derived from wind data were found to be small.

  19. A High-Resolution 3D Weather Radar, MSG, and Lightning Sensor Observation Composite

    NASA Astrophysics Data System (ADS)

    Diederich, Malte; Senf, Fabian; Wapler, Kathrin; Simmer, Clemens

    2013-04-01

    Within the research group 'Object-based Analysis and SEamless prediction' (OASE) of the Hans Ertel Centre for Weather Research programme (HerZ), a data composite containing weather radar, lightning sensor, and Meteosat Second Generation observations is being developed for the use in object-based weather analysis and nowcasting. At present, a 3D merging scheme combines measurements of the Bonn and Jülich dual polarimetric weather radar systems (data provided by the TR32 and TERENO projects) into a 3-dimensional polar-stereographic volume grid, with 500 meters horizontal, and 250 meters vertical resolution. The merging takes into account and compensates for various observational error sources, such as attenuation through hydrometeors, beam blockage through topography and buildings, minimum detectable signal as a function of noise threshold, non-hydrometeor echos like insects, and interference from other radar systems. In addition to this, the effect of convection during the radar 5-minute volume scan pattern is mitigated through calculation of advection vectors from subsequent scans and their use for advection correction when projecting the measurements into space for any desired timestamp. The Meteosat Second Generation rapid scan service provides a scan in 12 spectral visual and infrared wavelengths every 5 minutes over Germany and Europe. These scans, together with the derived microphysical cloud parameters, are projected into the same polar stereographic grid used for the radar data. Lightning counts from the LINET lightning sensor network are also provided for every 2D grid pixel. The combined 3D radar and 2D MSG/LINET data is stored in a fully documented netCDF file for every 5 minute interval, and is made ready for tracking and object based weather analysis. At the moment, the 3D data only covers the Bonn and Jülich area, but the algorithms are planed to be adapted to the newly conceived DWD polarimetric C-Band 5 minute interval volume scan strategy. An extension of the 3D composite to all of Germany is therefore possible and set as a goal.

  20. Spectral evidence of size dependent space weathering processes on asteroid surfaces

    NASA Technical Reports Server (NTRS)

    Gaffey, M. J.; Bell, J. F.; Brown, R. H.; Burbine, T. H.; Piatek, J. L.; Reed, K. L.; Chaky, D. A.

    1993-01-01

    Most compositional characterizations of the minor planets are derived from analysis of visible and near-infrared reflectance spectra. However, such spectra are derived from light which has only interacted with a very thin surface layer. Although regolith processes are assumed to mix all near-surface lithologic units into this layer, it has been proposed that space weathering processes can alter this surface layer to obscure the spectral signature of the bedrock lithology. It has been proposed that these spectral alteration processes are much less pronounced on asteroid surfaces than on the lunar surface, but the possibility of major spectral alteration of asteroidal optical surfaces has been invoked to reconcile S-asteroids with ordinary chondrites. The reflectance spectra of a large subset of the S-asteroid population have been analyzed in a systematic investigation of the mineralogical diversity within the S-class. In this sample, absorption band depth is a strong function of asteroid diameter. The S-asteroid band depths are relatively constant for objects larger than 100 km and increase linearly by factor of two toward smaller sizes (approximately 40 km). Although the S-asteroid surface materials includes a diverse variety of silicate assemblages, ranging from dunites to basalts, all compositional subtypes of the S-asteroids conform to this trend. The A-, R-, and V-type asteroids which are primarily silicate assemblages (as opposed to the metal-silicate mixtures of most S-asteroids) follow a parallel but displaced trend. Some sort of textural or regolith equilibrium appears to have been attained in the optical surfaces of asteroids larger than about 100 km diameter but not on bodies below this size. The relationships between absorption band depth, spectral slope, surface albedo and body size provide an intriguing insight into the nature of the optical surfaces of the S-asteroids and space weathering on these objects.

  1. State of Art in space weather observational activities and data management in Europe

    NASA Astrophysics Data System (ADS)

    Stanislawska, Iwona

    One of the primary scientific and technical goals of space weather is to produce data in order to investigate the Sun impact on the Earth and its environment. Studies based on data mining philosophy yield increase the knowledge of space weather physical properties, modelling capabilities and gain applications of various procedures in space weather monitoring and forecasting. Exchanging tailored individually and/or jointly data between different entities, storing of the databases and making data accessible for the users is the most important task undertaken by investigators. National activities spread over Europe is currently consolidated pursuant to the terms of effectiveness and individual contributions embedded in joint integrated efforts. The role of COST 724 Action in animation of such a movement is essential. The paper focuses on the analysis of the European availability in the Internet near-real time and historical collections of the European ground based and satellite observations, operational indices and parameters. A detailed description of data delivered is included. The structure of the content is supplied according to the following selection: (1) observations, raw and/or corrected, updated data, (2) resolution, availability of real-time and historical data, (3) products, as the results of models and theory including (a) maps, forecasts and alerts, (b) resolution, availability of real-time and historical data, (4) platforms to deliver data. Characterization of the networking of stations, observatories and space related monitoring systems of data collections is integrated part of the paper. According to these provisions operational systems developed for these purposes is presented and analysed. It concerns measurements, observations and parameters from the theory and models referred to local, regional collections, European and worldwide networks. Techniques used by these organizations to generate the digital content are identified. As the reference pan-European and some national data centres and bases are described and compared with currently available data information provided worldwide and by relevant entities outside Europe. Current, follow up and expected future European space weather observational activities and data management perspectives in respect to European main lines of policy is the subject of the conclusions.

  2. Direct observation of reactant-product interfaces formed in natural weathering of exsolved, defective amphibole to smectite: Evidence for episodic, isovolumetric reactions involving structural inheritance

    NASA Astrophysics Data System (ADS)

    Banfield, Jillian F.; Barker, William W.

    1994-03-01

    High-resolution transmission electron microscopy (HRTEM) and energy-dispersive X-ray microanalysis (EDS) were employed to characterize grain boundary structures in naturally weathered amphibole. Our observations provide insights into the submicroscopic mineralogic controls on transport of solutions to and from reaction sites. Finely exsolved amphibole (anthophyllite/gedrite) in outcropping, slightly weathered gedrite gneiss transforms isovolumetrically to smectite. Stacking faults and exsolution lamellar boundaries focus weathering reactions, whereas chain width defects decrease the susceptibility of the surrounding amphibole to alteration. Relatively Al-poor anthophyllite lamellae alter slightly more readily than those of Al-rich gedrite. Large quantites of Mg, Fe, Si, and Al are removed from reaction sites. However, smectite compositions directly reflect <0.1 ?m-scale variations in Al:Mg:Si of coexisting anthophyllite and gedrite, supporting a transformation mechanism requiring very limited redistribution of elements incorporated into clay products. Topotactic relationships between products and reactants and interface structures suggest that smectite formation requires only partial depolymerization of amphibole structural units. Up to one-third of the amphibole I-beams may be directly inherited by smectite. Grain boundary structures within smectite mimic current amphibole-smectite interfaces and may represent previous reaction fronts. Such interfaces may be the result of episodic reaction, possibly attributable to the balance between rates of consumption of water by reactions and resupply by dewatering of larger fractures (which are themselves episodically supplied by rainfall). In this coherent, slightly weathered rock, transport of solution to and from reaction sites is restricted to diffusion along semi-coherent, subnanometer-wide grain boundaries and smectite interlayers. This contrasts with weathering grains within a soil, more deeply weathered rock, or laboratory mineral dissolution experiments, where a much larger volume of solution is in contact with weathering surfaces. We suggest that although transformation rates are limited by depolymerization and repolymerization at the amphibole-smectite interface, they may be modulated by episodicity in water supply to reaction sites within minerals.

  3. Incorporation of MODIS landcover data to improve land surface parameterization in the COAMPS numerical weather prediction model

    Microsoft Academic Search

    Valentine G. Anantharaj; Patrick J. Fitzpatrick; Roger L. King; Louis Wasson

    2004-01-01

    The vegetation and soil properties at the land surface exert significant influence over short-term weather forecasts of numerical weather prediction (NWP) models. The Coupled Ocean Atmosphere Mesoscale Prediction System (COAMPS) derives the necessary land surface properties from the USGS 1-km global land-use\\/land-cover (LULC) database, which is based on historical AVHRR data. A methodology has been developed to incorporate the LULC

  4. Surface Exposure Ages of Space-Weathered Grains from Asteroid 25143 Itokawa

    NASA Technical Reports Server (NTRS)

    Keller, L. P.; Berger, E. L.; Christoffersen, R.

    2015-01-01

    We use the observed effects of solar wind ion irradiation and the accumulation of solar flare particle tracks recorded in Itokawa grains to constrain the rates of space weathering and yield information about regolith dynamics. The track densities are consistent with exposure at mm depths for 104-105 years. The solar wind damaged rims form on a much faster timescale, <10(exp 3) years.

  5. Biochemical evolution II: Origin of life in tubular microstructures on weathered feldspar surfaces

    PubMed Central

    Parsons, Ian; Lee, Martin R.; Smith, Joseph V.

    1998-01-01

    Mineral surfaces were important during the emergence of life on Earth because the assembly of the necessary complex biomolecules by random collisions in dilute aqueous solutions is implausible. Most silicate mineral surfaces are hydrophilic and organophobic and unsuitable for catalytic reactions, but some silica-rich surfaces of partly dealuminated feldspars and zeolites are organophilic and potentially catalytic. Weathered alkali feldspar crystals from granitic rocks at Shap, north west England, contain abundant tubular etch pits, typically 0.4–0.6 ?m wide, forming an orthogonal honeycomb network in a surface zone 50 ?m thick, with 2–3 × 106 intersections per mm2 of crystal surface. Surviving metamorphic rocks demonstrate that granites and acidic surface water were present on the Earth’s surface by ?3.8 Ga. By analogy with Shap granite, honeycombed feldspar has considerable potential as a natural catalytic surface for the start of biochemical evolution. Biomolecules should have become available by catalysis of amino acids, etc. The honeycomb would have provided access to various mineral inclusions in the feldspar, particularly apatite and oxides, which contain phosphorus and transition metals necessary for energetic life. The organized environment would have protected complex molecules from dispersion into dilute solutions, from hydrolysis, and from UV radiation. Sub-micrometer tubes in the honeycomb might have acted as rudimentary cell walls for proto-organisms, which ultimately evolved a lipid lid giving further shelter from the hostile outside environment. A lid would finally have become a complete cell wall permitting detachment and flotation in primordial “soup.” Etch features on weathered alkali feldspar from Shap match the shape of overlying soil bacteria. PMID:9860941

  6. Surface Material Analysis of the S-type Asteroids: Removing the Space Weathering Effect from Reflectance Spectrum

    NASA Technical Reports Server (NTRS)

    Ueda, Y.; Miyamoto, M.; Mikouchi, T.; Hiroi, T.

    2003-01-01

    Recent years, many researchers have been observing a lot of asteroid reflectance spectra in the UV, visible to NIR at wavelength region. Reflectance spectroscopy of asteroid at this range should bring us a lot of information about its surface materials. Pyroxene and olivine have characteristic absorption bands in this wavelength range. Low-Ca pyroxene has two absorption bands around 0.9 microns and 1.9 microns. The more Ca and Fe content, the longer both absorption band centers. On the other hand, reflectance spectrum of olivine has three complicated absorption bands around 1 m, and no absorption feature around 2 microns. In general, reflectance spectra of many asteroids that are considered to be silicate rich (i.e., S- and A type asteroids) show redder slope and more subdued absorption bands than those of terrestrial minerals and meteorites. These features are now believed to be caused by the space weathering effect, which is probably caused by micrometeorite bombardment and/or solar wind. This process causes nanophase reduced iron (npFe(sup 0)) particles near the surface of mineral grains, which leads the optical change. Therefore, the space weathering effect should be removed from asteroid reflectance spectra to compare with those of meteorite and terrestrial minerals. In this report, we will apply the expanded modified Gaussian model (MGM) to the reflectance spectra of S-type asteroids 7 Iris and 532 Herculina and compare them with those of meteorites.

  7. THE FUTURE OF SEA SURFACE HEIGHT OBSERVATIONS

    Microsoft Academic Search

    Gary T. Mitchum; Robert Cheney; Yves Menard; Philip Woodworth

    A brief review of the use of sea surface height (SSH) data for climate- related research is given that serves to identify key constraints on a strategy for obtaining SSH observations in the future. The present status of the SSH observing system is reviewed, and a plan for the future observing system that builds on the present system is developed.

  8. A systematic review and meta-analysis of the effects of extreme weather events and other weather-related variables on Cryptosporidium and Giardia in fresh surface waters.

    PubMed

    Young, Ian; Smith, Ben A; Fazil, Aamir

    2015-03-01

    Global climate change is expected to impact drinking water quality through multiple weather-related phenomena. We conducted a systematic review and meta-analysis of the relationship between various weather-related variables and the occurrence and concentration of Cryptosporidium and Giardia in fresh surface waters. We implemented a comprehensive search in four databases, screened 1,228 unique citations for relevance, extracted data from 107 relevant articles, and conducted random-effects meta-analysis on 16 key relationships. The average odds of identifying Cryptosporidium oocysts and Giardia cysts in fresh surface waters was 2.61 (95% CI = 1.63-4.21; I² = 16%) and 2.87 (95% CI = 1.76-4.67; I² = 0%) times higher, respectively, during and after extreme weather events compared to baseline conditions. Similarly, the average concentration of Cryptosporidium and Giardia identified under these conditions was also higher, by approximately 4.38 oocysts/100 L (95% CI = 2.01-9.54; I(2) = 0%) and 2.68 cysts/100 L (95% CI = 1.08-6.55; I² = 48%). Correlation relationships between other weather-related parameters and the density of these pathogens were frequently heterogeneous and indicated low to moderate effects. Meta-regression analyses identified different study-level factors that influenced the variability in these relationships. The results can be used as direct inputs for quantitative microbial risk assessment. Future research is warranted to investigate these effects and potential mitigation strategies in different settings and contexts. PMID:25719461

  9. Reprinted from: Proceedings, International Workshop on Observations/Forecasting of Meso-scale Severe Weather and

    E-print Network

    Doswell III, Charles A.

    -scale Severe Weather and Technology of Reduction of Relevant Disasters (Tokyo, Japan), 22-26 February 1993, 181 on the ingredients for particular severe weather events, a focus is provided for the forecasting process of forecasters is discussed also, as a necessary component in a balanced approach to weather forecasting

  10. Development of a surface-specific, anti-weathering stone preservative treatment

    SciTech Connect

    Rao, S.M.; Brinkar, C.J. [Sandia National Lab., Albuquerque, NM (United States); Rao, S.M.; Ross, T.J. [Univ. of New Mexico, Albuquerque, NM (United States)] [and others

    1997-04-01

    We are testing an anti-weathering preservation strategy that is specific to limestone surfaces. The strategy involves the application of a mineral-specific, bifunctional, passivating/coupling agent that binds to both the limestone surface and to the consolidating inorganic polymer matrix. The sol-gel based reactions form composite materials with desirable conservation and anti-weathering properties. We present the results of our efforts, the highlights of which are: (1) scanning probe microscopy of moisture-free calcite crystals treated with the trisilanol form of silylalkylaminocarboxylate (SAAC), reveals porous agglomerates that offer no significant resistance to the mild leaching action of deionized water. When the crystals are further consolidated with a silica-based consolidant (A2**), no dissolution is seen although the positive role of the passivant molecule is not yet delineated. (2) Modulus of rupture tests on limestone cores treated with an aminoalkylsilane (AEAPS) and A2** showed a 25-35% increase in strength compared to the untreated samples. (3) Environmental scanning electron microscopy of treated limestone subjected to a concentrated acid attack showed degradation of the surface except in areas where thick layers of the consolidant were deposited.

  11. Weatherability Evaluation of Nanocomposite Polymeric Treatments for Surface Protection of Construction Materials

    SciTech Connect

    Scarfato, Paola; Letizia Fariello, Maria; Di Maio, Luciano; Incarnato, Loredana [University of Salerno, Department of Chemical and Food Engineering, Via Ponte don Melillo, 84084 Fisciano (Italy)] [Research Centre NANO lowbar MATES, University of Salerno, Via Ponte don Melillo, 84084 Fisciano (Italy)

    2010-06-02

    In this work the protective efficacy and stability against UV weathering of polymeric nanocomposites for concrete (CLS) surface protection have been evaluated. In particular, nanocomposite hybrids were prepared dispersing a commercial organomodified montmorillonite (Cloisite 30B) in two different polymeric matrices, one based on fluoroelastomers (Fluoline CP), the other on silane and siloxane (Antipluviol S). The obtained systems were characterized by several techniques (SAXD, DSC, TGA, FT-IR, contact angle measurements, colorimetry), before and after accelerated aging due to UV exposure, in order to evaluate the effect of the nanoscale dispersion of the organoclay on the properties and the UV stability of the treatments.

  12. Daymet: Daily Surface Weather Data on a 1-km Grid for North America, Version 2.

    NASA Astrophysics Data System (ADS)

    Devarakonda, R.

    2014-12-01

    Daymet: Daily Surface Weather Data and Climatological Summaries provides gridded estimates of daily weather parameters for North America, including daily continuous surfaces of minimum and maximum temperature, precipitation occurrence and amount, humidity, shortwave radiation, snow water equivalent, and day length. The current data product (Version 2) covers the period January 1, 1980 to December 31, 2013 [1]. Data are available on a daily time step at a 1-km x 1-km spatial resolution in Lambert Conformal Conic projection with a spatial extent that covers the North America as meteorological station density allows. Daymet data can be downloaded from 1) the ORNL Distributed Active Archive Center (DAAC) search and order tools (http://daac.ornl.gov/cgi-bin/cart/add2cart.pl?add=1219) or directly from the DAAC FTP site (http://daac.ornl.gov/cgi-bin/dsviewer.pl?ds_id=1219) and 2) the Single Pixel Tool (http://daymet.ornl.gov/singlepixel.html) and THREDDS (Thematic Real-time Environmental Data Services) Data Server (TDS) (http://daymet.ornl.gov/thredds_mosaics.html). The Single Pixel Data Extraction Tool [2] allows users to enter a single geographic point by latitude and longitude in decimal degrees. A routine is executed that translates the (lon, lat) coordinates into projected Daymet (x,y) coordinates. These coordinates are used to access the Daymet database of daily-interpolated surface weather variables. The Single Pixel Data Extraction Tool also provides the option to download multiple coordinates programmatically. The ORNL DAAC's TDS provides customized visualization and access to Daymet time series of North American mosaics. Users can subset and download Daymet data via a variety of community standards, including OPeNDAP, NetCDF Subset service, and Open Geospatial Consortium (OGC) Web Map/Coverage Service. References: [1] Thornton, P.E., M.M. Thornton, B.W. Mayer, N. Wilhelmi, Y. Wei, R. Devarakonda, and R.B. Cook. 2014. "Daymet: Daily Surface Weather Data on a 1-km Grid for North America, Version 2". Available [http://daac.ornl.gov] from Oak Ridge National Laboratory Distributed Active Archive Center, Oak Ridge, Tennessee, USA. [2] Devarakonda R., et al. 2012. Daymet: Single Pixel Data Extraction Tool. Available [http://daymet.ornl.go/singlepixel.html].

  13. AIRS Observations of DomeC in Antarctica and Comparison with Automated Weather Stations (AWS)

    NASA Technical Reports Server (NTRS)

    Aumann, Hartmut H.; Gregorich, Dave; Broberg, Steve

    2006-01-01

    We compare the surface temperatures at Dome Concordia (DomeC) deduced from AIRS data and two Automatic Weather Stations at Concordia Station: AWS8989 , which has been in operation since December 1996, and AWS.it, for which data are available between January and November 2005. The AWS8989 readings are on average 3 K warmer than the AWS.it readings, with a warmer bias in the Antarctic summer than in the winter season. Although AIRS measures the skin brightness temperature, while the AWS reports the temperature of the air at 3 meter above the surface, the AIRS measurements agree well with the AWS.it readings for all data and separately for the summer and winter seasons, if data taken in the presence of strong surface inversions are filtered out. This can be done by deducing the vertical temperature gradient above the surface directly from the AIRS temperature sounding channels or indirectly by noting that extreme vertical gradients near the surface are unlikely if the wind speed is more than a few meters per second. Since the AIRS measurements are very well calibrated, the agreement with AWS.it is very encouraging. The warmer readings of AWS8989 are likely due to thermal contamination of the AWS8989 site by the increasing activity at Concordia Station. Data from an AWS.it quality station could be used for the evaluation of radiometric accuracy and stability of polar orbiting sounders at low temperatures. Unfortunately, data from AWS.it was available only for a limited time. The thermal contamination of the AWS8989 data makes long-term trends deduced from AWS8989 and possibly results about the rapid Antarctic warming deduced from other research stations on Antarctica suspect. AIRS is the first hyperspectral infrared sounder designed in support of weather forecasting and climate research. It was launched in May 2002 on the EOS Aqua spacecraft into a 704 km altitude polar sun-synchronous orbit. The lifetime of AIRS, estimated before launch to be at least 5 years is, based on the latest evaluation, limited by the amount of attitude control gas on the EOS Aqua spacecraft, which is expected to last through 2015.

  14. Ground-based microwave weather radar observations and retrievals during the 2014 Holuhraun eruption (Bárðarbunga, Iceland)

    NASA Astrophysics Data System (ADS)

    Mereu, Luigi; Silvio Marzano, Frank; Barsotti, Sara; Montopoli, Mario; Yeo, Richard; Arngrimsson, Hermann; Björnsson, Halldór; Bonadonna, Costanza

    2015-04-01

    During an eruptive event the real-time forecasting of ash dispersal into the atmosphere is a key factor to prevent air traffic disasters. The ash plume is extremely hazardous to aircraft that inadvertently may fly through it. Real-time monitoring of such phenomena is crucial, particularly to obtain specific data for the initialization of eruption and dispersion models in terms of source parameters. The latter, such as plume height, ash concentration, mass flow rate and size spectra, are usually very difficult to measure or to estimate with a relatively good accuracy. Over the last years different techniques have been developed to improved ash plume detection and retrieval. Satellite-based observations, using multi-frequency visible and infrared radiometers, are usually exploited for monitoring and measuring dispersed ash clouds. The observations from geostationary orbit suffer from a relatively poor spatial resolution, whereas the low orbit level has a relatively poor temporal resolution. Moreover, the field-of-view of infrared radiometric measurements may be reduced by obstructions caused by water and ice clouds lying between the ground and the sensor's antenna. Weather radar-based observations represent an emerging technique to detect and, to a certain extent, mitigate the hazard from the ash plumes. Ground-based microwave scanning radar systems can provide the three-dimensional information about the detected ash volume with a fairly high spatial resolution every few minutes and in all weather conditions. Methodological studies have recently investigated the possibility of using single-polarization and dual-polarization ground-based radar for the remote sensing of volcanic ash cloud. In this respect, radar observations can be complementary to satellite observations. A microphysical electromagnetic characterization of volcanic ash was carried out in terms of dielectric properties, composition, size and orientation of ash particles. An extended Volcanic Ash Radar Retrieval (VARR) algorithm for single-polarization and double-polarization systems, shown in previous work, has been applied to C-band and X-band weather radar data. In this work we show radar based estimations of eruptive source parameters for Holuhraun events in the fall of 2014. This extremely gas-rich eruption was characterized by sustained lava fountaining in the first months. At the same time some ash-rich episodes were reported from the field together with minor tephra fallout occurring close to the eruption site. Since the beginning of the eruption, the Icelandic Meteorological Office (IMO) monitored the volcanic plume using two ground-based radars: a C-band weather radar (5.5 GHz) in Egilsstaðir and an X-band polarimetric mobile radar (9.4 GHz) located at Vaðalda, about 20 km away from the eruption site. The VARR algorithm has been applied to few specific events and the radar products, such as top plume height, concentration, ash load and mass flow rate, derived from the two radars, are here discussed in terms of retrievals and inter-comparisons with available in-situ information. Both radar-based estimations show a presence of volcanic particles in the observed plume. Also, airborne fine ash particles are identified at low levels of plume probably due to a wind-induced re-suspension of dust and ancient volcanic ash deposited in the area around Holuhraun.

  15. Plateau weather: A synoptic study of IAGO and ANARE observations in east Antarctica

    SciTech Connect

    Radok, U.; Wendler, G.

    1992-03-01

    Automatic weather stations (AWS) have been operated for a number of years by U.S. and French scientists cooperating in Project Interactions Atmosphere, Glace, Ocean (IAGO) and by the Australian National Antarctic Research Expeditions (ANARE). Six of these stations are sufficiently close to one another on the East Antarctic Plateau for a synoptic interpretation of their observations. The data for 1987 have been reduced to a common format in order to identify episodes of regionally coherent changes. One of these episodes is described and used to outline steps that will be needed for clarifying the relative importance of the local energy balance and the large-scale circulation for the onset, duration, and cessation of katabatic winds on the plateau.

  16. SURFACE MATERIAL ANALYSIS OF S-TYPE ASTEROIDS: REMOVING THE SPACE WEATHERING EFFECT FROM REFLECTANCE SPECTRUM. Y. Ueda1

    E-print Network

    Hiroi, Takahiro

    SURFACE MATERIAL ANALYSIS OF S-TYPE ASTEROIDS: REMOVING THE SPACE WEATHERING EFFECT FROM of asteroid reflectance spec- tra in the UV, visible to NIR at wavelength region [e.g., 1-4]. Reflectance spectroscopy of asteroid at this range should bring us a lot of information about its surface materials

  17. IDENTIFYING THE ROTATION RATE AND THE PRESENCE OF DYNAMIC WEATHER ON EXTRASOLAR EARTH-LIKE PLANETS FROM PHOTOMETRIC OBSERVATIONS

    E-print Network

    Seager, Sara

    IDENTIFYING THE ROTATION RATE AND THE PRESENCE OF DYNAMIC WEATHER ON EXTRASOLAR EARTH-LIKE PLANETS of hundreds of extrasolar planets, the search for planets like Earth and life in the uni- verse is quickly rocky planets, but they would not be able to spatially resolve a planet's surface. Using reflectance

  18. The main pillar: Assessment of space weather observational asset performance supporting nowcasting, forecasting, and research to operations

    PubMed Central

    Posner, A; Hesse, M; St Cyr, O C

    2014-01-01

    Space weather forecasting critically depends upon availability of timely and reliable observational data. It is therefore particularly important to understand how existing and newly planned observational assets perform during periods of severe space weather. Extreme space weather creates challenging conditions under which instrumentation and spacecraft may be impeded or in which parameters reach values that are outside the nominal observational range. This paper analyzes existing and upcoming observational capabilities for forecasting, and discusses how the findings may impact space weather research and its transition to operations. A single limitation to the assessment is lack of information provided to us on radiation monitor performance, which caused us not to fully assess (i.e., not assess short term) radiation storm forecasting. The assessment finds that at least two widely spaced coronagraphs including L4 would provide reliability for Earth-bound CMEs. Furthermore, all magnetic field measurements assessed fully meet requirements. However, with current or even with near term new assets in place, in the worst-case scenario there could be a near-complete lack of key near-real-time solar wind plasma data of severe disturbances heading toward and impacting Earth's magnetosphere. Models that attempt to simulate the effects of these disturbances in near real time or with archival data require solar wind plasma observations as input. Moreover, the study finds that near-future observational assets will be less capable of advancing the understanding of extreme geomagnetic disturbances at Earth, which might make the resulting space weather models unsuitable for transition to operations. Key Points Manuscript assesses current and near-future space weather assets Current assets unreliable for forecasting of severe geomagnetic storms Near-future assets will not improve the situation

  19. Weather Forecasting

    NSDL National Science Digital Library

    Twin Cities Public Television, Inc.

    2005-01-01

    This activity (on page 2 of the PDF) is a full inquiry investigation into meteorology and forecasting. Learners will research weather folklore, specifically looking for old-fashioned ways of predicting the weather. Then, they'll record observations of these predictors along with readings from their own homemade barometer, graphing the correct predictions for analysis. Relates to linked video, DragonflyTV: Forecasting.

  20. Global-scale Observations of the Limb and Disk (GOLD) - New Observing Capabilities for Space Weather Specification and Forecasting

    NASA Astrophysics Data System (ADS)

    Eastes, R.; Codrescu, M.; McClintock, W.; Aksnes, A.; Anderson, D.; Andersson, L.; Burns, A.; Budzien, S.; Daniell, R.; Dymond, K.; Eparvier, F.; Harvey, J.; Immel, T.; Krywonos, A.; Lankton, M.; Lumpe, J.; Prolss, G.; Richmond, A.; Rusch, D.; Siegmund, O.; Solomon, S.; Strickland, D.; Woods, T.

    2007-12-01

    The Global-scale Observations of the Limb and Disk (GOLD) mission of opportunity will fly an ultraviolet imaging spectrograph on a geostationary satellite to measure neutral densities and temperatures in the thermosphere and ionosphere. GOLD will provide the first global-scale observations of temperatures in the lower thermosphere, in addition to more familiar measurements such as aurora location and energy input; peak electron densities in the nighttime ionosphere; and atomic oxygen to molecular nitrogen (O/N2) ratios. GOLD can provide nearly continuous real-time observations of one hemisphere. In addition to measurements on the disk of the Earth, GOLD will also provide measurements of molecular oxygen densities and the temperature profile in the lower thermosphere on the limb of the Earth from stellar occultations. Combined with the advanced models now available, measurements from GOLD will revolutionize our understanding of the global-scale response of the thermosphere and ionosphere to geomagnetic and solar forcing. GOLD is being proposed as a mission of opportunity in response to the Small Explorer (SMEX) and Missions of Opportunity from NASA's Science Mission Directorate, and it would leverage the scheduled solar (Solar Dynamics Observatory) and radiation belt (Radiation Belt Storm Probes) measurements. The data and knowledge gained from GOLD will enhance space weather specification and forecasting capabilities.

  1. Weather Instruments

    NSDL National Science Digital Library

    This Topic in Depth discusses the variety of instruments used to collect climate and weather data. The first two websites provide simple introductions to the many weather instruments. Bethune Academy's Weather Center (1) discusses the functions of psychrometers, anemometers, weather balloons, thermometers, and barometers. The Illinois State Water Survey (2) furnishes many images of various instruments that collect data daily for legal issues, farmers, educators, students, and researchers. The third website (3), created by the Center for Improving Engineering and Science Education (CIESE), provides a classroom activity to educate users on how to build and use weather instruments. By the end of the group project, students should know all about wind vanes, rain gauges, anemometers, and thermometers. Next, the Miami Museum of Science provides a variety of activities to help students learn about the many weather instruments including wind scales and wind chimes (4). Students can learn about the wind, air pressure, moisture, and temperature. At the fifth website, the Tyson Research Center at Washington University describes the devices it uses in its research (5). At the various links, users can find out the center's many projects that utilize meteorological data such as acid rain monitoring. The sixth website, a pdf document created by Dr. John Guyton at the Mississippi State University Extension Service, provides guidance to teachers about the education of weather patterns and instruments (6). Users can find helpful information on pressure systems, humidity, cloud patterns, and much more. Next, the University of Richmond discusses the tools meteorologists use to learn about the weather (7). While providing materials about the basic tools discussed in the other websites, this site also offers information about weather satellites, radar, and computer models. After discovering the many weather instruments, users can learn about weather data output and analysis at the Next Generation Weather Lab website (8). This expansive website provides an abundance of surface data and upper air data as well as satellite and radar images for the United States.

  2. Verification of ensemble forecasts of Mediterranean high-impact weather events against satellite observations

    NASA Astrophysics Data System (ADS)

    Chaboureau, J.-P.; Nuissier, O.; Claud, C.

    2012-08-01

    Ensemble forecasts at kilometre scale of two severe storms over the Mediterranean region are verified against satellite observations. In complement to assessing the forecasts against ground-based measurements, brightness temperature (BT) images are computed from forecast fields and directly compared to BTs observed from satellite. The so-called model-to-satellite approach is very effective in identifying systematic errors in the prediction of cloud cover for BTs in the infrared window and in verifying the forecasted convective activity with BTs in the microwave range. This approach is combined with the calculation of meteorological scores for an objective evaluation of ensemble forecasts. The application of the approach is shown in the context of two Mediterranean case studies, a tropical-like storm and a heavy precipitating event. Assessment of cloud cover and convective activity using satellite observations in the infrared (10.8 ?m) and microwave regions (183-191 GHz) provides results consistent with other traditional methods using rainfall measurements. In addition, for the tropical-like storm, differences among forecasts occur much earlier in terms of cloud cover and deep convective activity than they do in terms of deepening and track. Further, the underdispersion of the ensemble forecasts of the two high-impact weather events is easily identified with satellite diagnostics. This suggests that such an approach could be a useful method for verifying ensemble forecasts, particularly in data-sparse regions.

  3. Are weather models better than gridded observations for precipitation in the mountains? (Invited)

    NASA Astrophysics Data System (ADS)

    Gutmann, E. D.; Rasmussen, R.; Liu, C.; Ikeda, K.; Clark, M. P.; Brekke, L. D.; Arnold, J.; Raff, D. A.

    2013-12-01

    Mountain snowpack is a critical storage component in the water cycle, and it provides drinking water for tens of millions of people in the Western US alone. This water store is susceptible to climate change both because warming temperatures are likely to lead to earlier melt and a temporal shift of the hydrograph, and because changing atmospheric conditions are likely to change the precipitation patterns that produce the snowpack. Current measurements of snowfall in complex terrain are limited in number due in part to the logistics of installing equipment in complex terrain. We show that this limitation leads to statistical artifacts in gridded observations of current climate including errors in precipitation season totals of a factor of two or more, increases in wet day fraction, and decreases in storm intensity. In contrast, a high-resolution numerical weather model (WRF) is able to reproduce observed precipitation patterns, leading to confidence in its predictions for areas without measurements and new observations support this. Running WRF for a future climate scenario shows substantial changes in the spatial patterns of precipitation in the mountains related to the physics of hydrometeor production and detrainment that are not captured by statistical downscaling products. The stationarity in statistical downscaling products is likely to lead to important errors in our estimation of future precipitation in complex terrain.

  4. Groundwater/surface-water interactions on deeply weathered surfaces of low relief: evidence from Lakes Victoria and Kyoga, Uganda

    NASA Astrophysics Data System (ADS)

    Owor, Michael; Taylor, Richard; Mukwaya, Christine; Tindimugaya, Callist

    2011-11-01

    Little is known of the interactions between groundwater and surface water on deeply weathered landscapes of low relief in the Great Lakes Region of Africa (GLRA). The role of groundwater in sustaining surface-water levels during periods of absent rainfall is disputed and groundwater is commonly excluded from estimations of surface-water balances. Triangulated piezometers installed beside lake gauging stations on Lake Victoria and Lake Kyoga in Uganda provide the first evidence of the dynamic interaction between groundwater and surface water in the GLRA. Stable isotope ratios (2H:1H, 18O:16O) support piezometric evidence that groundwater primarily discharges to lakes but show further that mixing of groundwater and lake water has occurred at one site on Lake Victoria (Jinja). Layered-aquifer heterogeneity, wherein fluvial-lacustrine sands overlie saprolite, gives rise to both rapid and slow groundwater fluxes to lakes which is evident from the recession of borehole hydrographs following recharge events. Darcy throughflow calculations suggest that direct contributions from groundwater to Lake Victoria comprise <1% of the total inflows to the lake. Groundwater/surface-water interactions are strongly influenced by changing drainage base (lake) levels that are controlled, in part, by regional climate variability and dam releases from Lake Victoria (Jinja).

  5. An observed connection between wintertime temperature anomalies over Northwest China and weather regime transitions in North Atlantic

    NASA Astrophysics Data System (ADS)

    Li, Chao; Zhang, Qingyun

    2015-04-01

    In this study, the association between wintertime temperature anomalies over Northwest China and the weather regime transitions in North Atlantic on synoptic scale is analyzed by using observational surface air temperature (SAT) data and atmospheric reanalysis data. Daily SAT anomaly and duration time are used in order to define SAT anomaly cases. Differences with regard to the circulation anomalies over the Ural Mountains and the upstream North Atlantic area are evident. It is found that the colder than normal SAT is caused by the enhanced Ural high and associated southward flow over Northwest China. Time-lagged composites reveal possible connections between the SAT anomalies and the different development phases of the North Atlantic Oscillation (NAO). The Ural highs tend to be strengthened during the negative phase of NAO (NAO-) to Atlantic ridge transition, which are closely related to the downstream-propagating Rossby wave activity. The opposite circulation patterns are observed in the warm SAT cases. A cyclonic circulation anomaly is distinctly enhanced over the Urals during the positive phase of NAO (NAO+) to Scandinavian blocking transition, which would cause warmer SAT over Northwest China. Further analyses suggest that the intensified zonal wind over North Atlantic would favor the NAO- to Atlantic ridge transition, while the weakened zonal wind may be responsible for the transition between NAO+ and Scandinavian blocking.

  6. Vertical structure of the wind field during the special observing period I of the global weather experiment

    Microsoft Academic Search

    J. N. Paegle; Z. Zhen; G. Sampson

    1984-01-01

    Summary The vertical structure of the global atmosphere is analyzed for selected periods of the Special Observing Period I (SOP-I) for the Global Weather Experiment (GWE). The analysis consists of projection of the streamfunction and velocity potential at 200 and 850 mb on spherical harmonics and of the wind and height fields on the normal modes of a linearized form

  7. The Main Pillar: Assessment of Space Weather Observational Asset Performance Supporting Nowcasting, Forecasting and Research to Operations

    NASA Technical Reports Server (NTRS)

    Posner, Arik; Hesse, Michael; SaintCyr, Chris

    2014-01-01

    Space weather forecasting critically depends upon availability of timely and reliable observational data. It is therefore particularly important to understand how existing and newly planned observational assets perform during periods of severe space weather. Extreme space weather creates challenging conditions under which instrumentation and spacecraft may be impeded or in which parameters reach values that are outside the nominal observational range. This paper analyzes existing and upcoming observational capabilities for forecasting, and discusses how the findings may impact space weather research and its transition to operations. A single limitation to the assessment is lack of information provided to us on radiation monitor performance, which caused us not to fully assess (i.e., not assess short term) radiation storm forecasting. The assessment finds that at least two widely spaced coronagraphs including L4 would provide reliability for Earth-bound CMEs. Furthermore, all magnetic field measurements assessed fully meet requirements. However, with current or even with near term new assets in place, in the worst-case scenario there could be a near-complete lack of key near-real-time solar wind plasma data of severe disturbances heading toward and impacting Earth's magnetosphere. Models that attempt to simulate the effects of these disturbances in near real time or with archival data require solar wind plasma observations as input. Moreover, the study finds that near-future observational assets will be less capable of advancing the understanding of extreme geomagnetic disturbances at Earth, which might make the resulting space weather models unsuitable for transition to operations.

  8. Exploring Weather

    NSDL National Science Digital Library

    Miss Emily

    2010-01-29

    Second Grade Standard 3: Students will develop an understanding of their environment. Objective 2: Observe and describe weather. Indicator a: Observe and describe patterns of change in weather. Monday, February 1st: Look at the five-day forecast for Salt Lake City, Utah at Five day forecasts. The high temperature for the day will be in red and the low temperature will be in blue. Make sure you look at the temperature listed in degrees Farenheit (F) not degrees Celcius (C). Make ...

  9. Unisys Weather

    NSDL National Science Digital Library

    The Unisys weather website offers a host of weather analyses and forecasts. In the Analyses link, visitors can find satellite images as well as surface, upper air, and radar images. Visitors can learn the intricacies of Unisys's many forecast models such as the Nested Grid Model (NGM), Aviation Model, and the Rapid Update Cycle (RUC) Model. Users can find archived hurricane data for the Atlantic, the Eastern Pacific, and the Western Pacific. The site also furnishes archived surface maps, infrared satellite images, upper air charts, and sea surface temperature (SST) plots.

  10. Understanding Aviation Meteorology and Weather Hazards with Ground-Based Observations

    Microsoft Academic Search

    Christian Pagé

    \\u000a Meteorology is no doubt important for aviation, as weather hazards have a significant negative impact on aircraft safety and\\u000a traffic delay. Based on recent surveys, 20–30% of worldwide air accidents and as much as 22% of air traffic delays are due\\u000a to to adverse weather conditions. Information on thunderstorms, ceiling and visibility, wind shear, turbulence, and aircraft\\u000a icing conditions are

  11. Weathering and vegetation controls on nickel isotope fractionation in surface ultramafic environments (Albania)

    NASA Astrophysics Data System (ADS)

    Estrade, Nicolas; Cloquet, Christophe; Echevarria, Guillaume; Sterckeman, Thibault; Deng, Tenghaobo; Tang, YeTao; Morel, Jean-Louis

    2015-08-01

    The dissolved nickel (Ni) isotopic composition of rivers and oceans presents an apparent paradox. Even though rivers represent a major source of Ni in the oceans, seawater is more enriched in the heavier isotopes than river-water. Additional sources or processes must therefore be invoked to account for the isotopic budget of dissolved Ni in seawater. Weathering of continental rocks is thought to play a major role in determining the magnitude and sign of isotopic fractionation of metals between a rock and the dissolved product. We present a study of Ni isotopes in the rock-soil-plant systems of several ultramafic environments. The results reveal key insights into the magnitude and the control of isotopic fractionation during the weathering of continental ultramafic rocks. This study introduces new constraints on the influence of vegetation during the weathering process, which should be taken into account in interpretations of the variability of Ni isotopes in rivers. The study area is located in a temperate climate zone within the ophiolitic belt area of Albania. The serpentinized peridotites sampled present a narrow range of heavy Ni isotopic compositions (?60Ni = 0.25 ± 0.16 ‰, 2SD n = 2). At two locations, horizons within two soil profiles affected by different degrees of weathering all presented light isotopic compositions compared to the parent rock (?60Nisoil-rock up to - 0.63 ‰). This suggests that the soil pool takes up the light isotopes, while the heavier isotopes remain in the dissolved phase. By combining elemental and mineralogical analyses with the isotope compositions determined for the soils, the extent of fractionation was found to be controlled by the secondary minerals formed in the soil. The types of vegetation growing on ultramafic-derived soils are highly adapted and include both Ni-hyperaccumulating species, which can accumulate several percent per weight of Ni, and non-accumulating species. Whole-plant isotopic compositions were found to be isotopically heavier than the soil (?60Niwhole plant-soil up to 0.40‰). Fractions of Ni extracted by DTPA (diethylenetriaminepentaacetic acid) presented isotopically heavy compositions compared to the soil (?60NiDTPA-soil up to 0.89‰), supporting the hypothesis that the dissolved Ni fraction controlled by weathering has a heavy isotope signature. The non-hyperaccumulators (n = 2) were inclined to take up and translocate light Ni isotopes with a large degree of fractionation (?60Nileaves-roots up to - 0.60 ‰). For Ni-hyperaccumulators (n = 7), significant isotopic fractionation was observed in the plants in their early growth stages, while no fractionation occurred during later growth stages, when plants are fully loaded with Ni. This suggests that (i) the high-efficiency translocation process involved in hyperaccumulators does not fractionate Ni isotopes, and (ii) the root uptake process mainly controls the isotopic composition of the plant. In ultramafic contexts, vegetation composed of hyperaccumulators can significantly influence isotopic compositions through its remobilization in the upper soil horizon, thereby influencing the isotopic balance of Ni exported to rivers.

  12. Estimation of surface longwave radiation components from ground-based historical net radiation and weather data

    Microsoft Academic Search

    Gi-Hyeon Park; Xiaogang Gao; Soroosh Sorooshian

    2008-01-01

    A methodology for estimating ground upwelling, clear-sky and cloud downwelling longwave radiations (L ?, L sky ?, and L cld ?) and net shortwave radiation (S n ) at 30-min temporal scales based on long-term ground-based net radiations and meteorological observations is described. Components of surface radiation can be estimated from empirical models, cloud radiation models, and remote sensing observations.

  13. Observation and research for strong meteor shower and related catastrophic space weather

    NASA Astrophysics Data System (ADS)

    Ma, Y. H.; He, Y. W.; Xu, P. X.; Zhao, H. B.

    2007-07-01

    During the first international joint observation for strong meteor shower, we made multi-subject observations for Leonids and Draconids and their disaster space weather events by several methods. Combining the synthetical analysis of Leonids, Perseids and Draconids and their related data from 1957 to 2003, we sufficiently confirm that the periodic strong meteor showers can result in the formation of catastrophic space weather events. The following summing-up is confirmed basically: 1.The formation mechanism of the strong meteor shower There are meteoroids with high density and uneven distribution close the cometary nucleus, especially in the direction of opposite the Sun and backside of the nucleus. They can stretch 1-11AU along the cometary orbit and 1-5 (&sim10^3AU) cross the orbit. Therefore good displays of meteor shower (10---100 times as usual) or storms (103---104 times as usual) can occur when the Earth passes a high density meteoroid stream during the period of 3 years before and 5 years after the perihelion passage of the comet. During that period, bolides or shooting stars which are serious harmful to spaceflight security increase greatly to 3%~10%. This corrects the wrong point of view that the harmful micro-meteoroids to spaceflight security in period meteor showers are <1 g only. 2. The cosmic dust maintaining mechanism of long-life Es layer in mid-latitude area It is proved the life of Es layer increased greatly when most ions are long-life metal type ions (Fe +, Mg + ?? ) which composite coefficient is much smaller than that of molecule type ions(O2 + , NO + ?? ). The observation for about 50 years roughly approves that the blanketing frequency of Es layer (fb Es) abnormally increase in large area (>105km2) and lasting long time (>15 min) only when strong meteor shower occurred at night. It is not f, l and c type Es layer evolved from sequence Es layer. This shows that the cause of fb Es increase is that the ionosphere was bombarded by an additional swarm of cometary dusts, much smaller than those which produce an ionization trail that can be detected by radio detectors. 3. Spaceflight security During the strong meteor shower, bolides or shooting stars which mass may >1 g increase obviously. Since its kinetic energy is great, a bolide will explode when impacting on spacecraft to produce compress waves passing to inner wall, therefore possibly result in break, except for bringing sunken marks on the outer wall. In a word, the possible damage of strong meteor showers to big spacecraft and long time staying spacecraft can not be neglect. Launch of spaceflight should be evaded and security step for spaceflight in orbit should be taken during the strong meteor shower.

  14. Neutron Monitor Observations and Space Weather, 1. Automatically Search of Great Solar Energetic Particle Event Beginning.

    NASA Astrophysics Data System (ADS)

    Dorman, L. I.; Pustil'Nik, L. A.; Sternlieb, A.; Zukerman, I. G.

    It is well known that in periods of great SEP fluxes of energetic particles can be so big that memory of computers and other electronics in space may be destroyed, satellites and spacecrafts became dead: according to NOAA Space Weather Scales are danger- ous Solar Radiation Storms S5-extreme (flux level of particles with energy > 10 MeV more than 10^5), S4-severe (flux more than 10^4) and S3-strong (flux more than 10^3). In these periods is necessary to switch off some part of electronics for few hours to protect computer memories. These periods are also dangerous for astronauts on space- ships, and passengers and crew in commercial jets (especially during S5 storms). The problem is how to forecast exactly these dangerous phenomena. We show that exact forecast can be made by using high-energy particles (few GeV/nucleon and higher) which transportation from the Sun is characterized by much bigger diffusion coeffi- cient than for small and middle energy particles. Therefore high energy particles came from the Sun much more early (8-20 minutes after acceleration and escaping into so- lar wind) than main part of smaller energy particles caused dangerous situation for electronics (about 30-60 minutes later). We describe here principles and experience of automatically working of program "FEP-Search". The positive result which shows the exact beginning of FEP event on the Emilio Segre' Observatory (2025 m above sea level, Rc=10.8 GV), is determined now automatically by simultaneously increas- ing on 2.5 St. Dev. in two sections of neutron supermonitor. The next 1-min data the program "FEP-Search" uses for checking that the observed increase reflects the begin- ning of real great FEP or not. If yes, automatically starts to work on line the programs "FEP-Research".

  15. Lunar Surface Properties from Diviner Eclipse Observations

    NASA Astrophysics Data System (ADS)

    Hayne, Paul; Paige, David; Greenhagen, Benjamin; Bandfield, Joshua; Siegler, Matthew; Lucey, Paul

    2015-04-01

    The thermal behavior of planetary bodies can reveal information about fundamental processes shaping their surfaces and interiors. Diviner [1] has been mapping the Moon's diurnal temperatures since the Lunar Reconnaissance Orbiter (LRO) arrived in 2009, yielding new insights into regolith formation [2, 3], the distribution of volatiles [4, 5], lunar volcanism [6, 7, 8], and impact processes [9]. The Moon's cooling during eclipse provides complementary information on the physical properties of the uppermost surface layer, which can be used to further investigate these and other processes. We used data from Diviner's seven thermal infrared spectral channels to measure surface temperatures before, during and after the 8 Oct., 2014 eclipse. In its standard nadir-pushbroom mode, Diviner maps surface temperatures in a ~6-km swath with a spatial resolution of ~250 m. Using Diviner's independent scanning capability [11], we also targeted two regions of interest on sequential orbits to create a time series of thermal observations: 1) Kepler crater (-38°E, 8°N) and 2) an unnamed nighttime "cold spot" (-33.3°E, 3°N). Pre-eclipse surface temperatures in these regions were ~380 K. As a relatively young Copernican-aged impact crater, Kepler was selected to investigate the abundance and size distribution of rocks in the ejecta and interior. Lunar nighttime "cold spots" are anomalous features around very young impact craters, extending for up to hundreds of crater radii, notable for their low temperatures in the Diviner nighttime data [9]. Although their origins are not fully explained, they are likely the result of in-situ disruption and decompression of regolith during the impact process. The selected cold spot (one of hundreds or even thousands on the lunar surface) was located with good viewing ge- ometry from LRO, and had a diameter of ~10 km surrounding a crater < 1 km in diameter. At Kepler crater, we observed dramatic differences in the amount of cooling related to the presence of blocky ejecta material. Comparisons of the rock abundance derived from the eclipse measurements can be made to those derived from the standard Diviner diurnal data [2] in order to constrain the rock size distribution. At a small nighttime cold spot, we observed brightness temperatures during the eclipse that were more than 10K higher than those observed in surrounding non-cold-spot regions. This seemingly paradoxical result implies that the vertical stratigraphy of the Moon's near-surface regolith may be more complex than has been previously appreciated. We are in the process of evaluating several possible explanations for this phenomenon quantitatively. References: [1] Paige D. A., et al. (2010) Space Sci. Rev. 150, 125-160. [2] Bandfield J. L., et al. (2011) J. Geophys. Res., 116, E12. [3] Ghent R. R., et al. (2014) Geology, 42 (12), 1059-1062. [4] Paige D. A., et al. (2010) Science, 330, 479-482. [5] Hayne P. O., et al. (2015) Icarus, submitted. [6] Greenhagen B. T., et al. (2010) Science, 329, 1507-1509. [7] Glotch T. D., et al. (2010) Science, 329, 1510-1513. [8] Allen C. C., et al. (2012) J. Geophys. Res., 117, E12. [9] Bandfield J. L., et al. (2014) Icarus, 231, 221-231. [10] Hayne P. O., et al. (2011) AGU Fall Meeting Abstracts, p. 1712. [11] Hayne P. O., et al. (2010) Science, 330, 477-479. Acknowledgement: Part of this work was performed at the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration.

  16. Weather Forecasting

    NSDL National Science Digital Library

    John Nielsen-Gammon

    1996-09-01

    Weather Forecasting is a set of computer-based learning modules that teach students about meteorology from the point of view of learning how to forecast the weather. The modules were designed as the primary teaching resource for a seminar course on weather forecasting at the introductory college level (originally METR 151, later ATMO 151) and can also be used in the laboratory component of an introductory atmospheric science course. The modules assume no prior meteorological knowledge. In addition to text and graphics, the modules include interactive questions and answers designed to reinforce student learning. The module topics are: 1. How to Access Weather Data, 2. How to Read Hourly Weather Observations, 3. The National Collegiate Weather Forecasting Contest, 4. Radiation and the Diurnal Heating Cycle, 5. Factors Affecting Temperature: Clouds and Moisture, 6. Factors Affecting Temperature: Wind and Mixing, 7. Air Masses and Fronts, 8. Forces in the Atmosphere, 9. Air Pressure, Temperature, and Height, 10. Winds and Pressure, 11. The Forecasting Process, 12. Sounding Diagrams, 13. Upper Air Maps, 14. Satellite Imagery, 15. Radar Imagery, 16. Numerical Weather Prediction, 17. NWS Forecast Models, 18. Sources of Model Error, 19. Sea Breezes, Land Breezes, and Coastal Fronts, 20. Soundings, Clouds, and Convection, 21. Snow Forecasting.

  17. Estimation of surface longwave radiation components from ground-based historical net radiation and weather data

    Microsoft Academic Search

    Gi-Hyeon Park; Xiaogang Gao; Soroosh Sorooshian

    2008-01-01

    A methodology for estimating ground upwelling, clear-sky and cloud downwelling longwave radiations (L?, Lsky?, and Lcld?) and net shortwave radiation (Sn) at 30-min temporal scales based on long-term ground-based net radiations and meteorological observations is described. Components of surface radiation can be estimated from empirical models, cloud radiation models, and remote sensing observations. The proposed method combines the local calibration

  18. Observations of space weather events from the Sun to the Earth ionosphere and thermosphere

    Microsoft Academic Search

    C. Hanuise

    2006-01-01

    Solar events and their impact on the terrestrial environment have received a lot of attention in recent years Nevertheless the relations between the solar source and their effects in the terrestrial environment are far from being understood quantitatively let it be for the physical mechanisms solar-terrestrial physics or for the effects on living bodies and technological systems space weather Are

  19. NEXRAD Weather Radar Observations of the 2006 Augustine Volcanic Eruption Clouds

    Microsoft Academic Search

    D. J. Schneider; C. Scott; J. Wood; T. Hall

    2006-01-01

    The 2006 eruption of Augustine Volcano, Alaska provided an exceptional opportunity to detect and measure explosive volcanic events and to track drifting volcanic clouds using WRS-88D (NEXRAD) weather radar data. Radar data complemented the real-time seismic monitoring by providing rapid confirmation of ash generation and cloud height. The explosive phase of the eruption consisted of thirteen discrete Vulcanian explosions from

  20. Weather Maps in Motion

    NSDL National Science Digital Library

    Charles Burrows

    In this activity, students learn to interpret current weather maps. They will observe weather map loop animations on the internet, learn the concept of Zulu time (Universal Time Coordinated, UTC) and visualize the movement of fronts and air masses. They will then analyze a specific weather station model, generate a meteogram from their observations, and answer a set of questions about their observations.

  1. Space Weathering Products Found on the Surfaces of the Itokawa Dust Particles: A Summary of the Initial Analysis

    NASA Technical Reports Server (NTRS)

    Noguchi, T.; Kimura, M.; Hashimoto, T.; Konno, M.; Nakamura, T.; Ogami, T.; Ishida, H.; Sagae, R.; Tsujimoto, S.; Tsuchiyama, A,; Zolensky, M. E.; Tanaka, M.; Fujimura, A.; Abe, M.; Yada, T.; Mukai, T.; Ueno, M.; Okada, T.; Shirai, K.; Ishibashi, Y.; Okazaki, R.

    2012-01-01

    Surfaces of airless bodies exposed to interplanetary space gradually have their structures, optical properties, chemical compositions, and mineralogy changed by solar wind implantation and sputtering, irradiation by galactic and solar cosmic rays, and micrometeorite bombardment. These alteration processes and the resultant optical changes are known as space weathering [1, 2, 3]. Our knowledge of space weathering has depended almost entirely on studies of the surface materials returned from the Moon and regolith breccia meteorites [1, 4, 5, 6] until the surface material of the asteroid Itokawa was returned to the Earth by the Hayabusa spacecraft [7]. Lunar soil studies show that space weathering darkens the albedo of lunar soil and regolith, reddens the slopes of their reflectance spectra, and attenuates the characteristic absorption bands of their reflectance spectra [1, 2, 3]. These changes are caused by vapor deposition of small (<40 nm) metallic Fe nanoparticles within the grain rims of lunar soils and agglutinates [5, 6, 8]. The initial analysis of the Itokawa dust particles revealed that 5 out of 10 particles have nanoparticle-bearing rims, whose structure varies depending on mineral species. Sulfur-bearing Fe-rich nanoparticles (npFe) exist in a thin (5-15 nm) surface layer (zone I) on olivine, low-Ca pyroxene, and plagioclase, suggestive of vapor deposition. Sulfur-free npFe exist deeper inside (<60 nm) ferromagnesian silicates (zone II). Their texture suggests formation by amorphization and in-situ reduction of Fe2+ in ferromagnesian silicates [7]. On the other hand, nanophase metallic iron (npFe0) in the lunar samples is embedded in amorphous silicate [5, 6, 8]. These textural differences indicate that the major formation mechanisms of the npFe0 are different between the Itokawa and the lunar samples. Here we report a summary of the initial analysis of space weathering of the Itokawa dust particles.

  2. Simulation studies of the impact of future observing systems on weather prediction

    NASA Technical Reports Server (NTRS)

    Atlas, R.; Kalnay, E.; Baker, W. E.; Susskind, J.; Reuter, D.; Halem, M.

    1985-01-01

    The features and preliminary results from a simulation system being implemented to develop realistic estimates of the impacts future data acquisition systems will have on large-scale numerical weather simulation are described. The new instruments may include advanced passive IR and microwave satellite sensors, as well as active scatterometer and lidar sounders. A main goal of the impact study is to identify those sensor systems which will provide the most benefit. The realism of the study is being enhanced by assimilating as much real-world data as possible and generating global weather maps for comparison with maps generated on the bases on the projected new, higher resolution data. Early results have indicated a preference for higher resolution wind data than for temperature data for making 1-5 day forecasts. The prime instrument candidate for collecting the data is lidar, provided the sensor resolution design goals are met.

  3. A comparison between weather simulated within the Erosion/Productivity Impact Calculator (EPIC) and observed data

    E-print Network

    Wallis, Trevor W.R

    1992-01-01

    , with limits set by the appropriate wet or dry day monthly mean values. To complete the required weather package it is necessary to incorporate wind data but, possibly because it is considered to be of less importance to agriculture than rain or temperature..., linle attention has been paid to either distribution or correlation. Crawford et al. (1971) discussed a Markovian process for wind direction selection but their technique is not applicable to crop modeling requirements. The method used in EPIC...

  4. Neutron Monitor Observations and Space Weather, 1. Automatically Search of Great Solar Energetic Particle Event Beginning

    Microsoft Academic Search

    L. I. Dorman; L. A. Pustil'Nik; A. Sternlieb; I. G. Zukerman

    2002-01-01

    It is well known that in periods of great SEP fluxes of energetic particles can be so big that memory of computers and other electronics in space may be destroyed, satellites and spacecrafts became dead: according to NOAA Space Weather Scales are danger- ous Solar Radiation Storms S5-extreme (flux level of particles with energy > 10 MeV more than 10^5),

  5. Open Surface Solar Irradiance Observations - A Challenge

    NASA Astrophysics Data System (ADS)

    Menard, Lionel; Nüst, Daniel; Jirka, Simon; Maso, Joan; Ranchin, Thierry; Wald, Lucien

    2015-04-01

    The newly started project ConnectinGEO funded by the European Commission aims at improving the understanding on which environmental observations are currently available in Europe and subsequently providing an informational basis to close gaps in diverse observation networks. The project complements supporting actions and networking activities with practical challenges to test and improve the procedures and methods for identifying observation data gaps, and to ensure viability in real world scenarios. We present a challenge on future concepts for building a data sharing portal for the solar energy industry as well as the state of the art in the domain. Decision makers and project developers of solar power plants have identified the Surface Solar Irradiance (SSI) and its components as an important factor for their business development. SSI observations are crucial in the process of selecting suitable locations for building new plants. Since in-situ pyranometric stations form a sparse network, the search for locations starts with global satellite data and is followed by the deployment of in-situ sensors in selected areas for at least one year. To form a convincing picture, answers must be sought in the conjunction of these EO systems, and although companies collecting SSI observations are willing to share this information, the means to exchange in-situ measurements across companies and between stakeholders in the market are still missing. We present a solution for interoperable exchange of SSI data comprising in-situ time-series observations as well as sensor descriptions based on practical experiences from other domains. More concretely, we will apply concepts and implementations of the Sensor Web Enablement (SWE) framework of the Open Geospatial Consortium (OGC). The work is based on an existing spatial data infrastructure (SDI), which currently comprises metadata, maps and coverage data, but no in-situ observations yet. This catalogue is already registered in the GEOSS Common Infrastructure (GCI). We describe the challenges and approach to introduce a suite of standards and best practices into the GEO Energy Societal Benefit Area for solar radiation measurements. Challenges range from spatio-temporal coverage across different scales and data quality to intellectual property rights and existing terminology. The approach includes means to share observations based on standardized data and metadata models and a user-friendly data exploration/management tool. The possibility to access and share data considerably improves the information base for strategic planning and control of new solar power resources. The platform will be integrated as a new component into the Webservice-Energy.org GEOSS Community Portal dedicated to Energy and Environment. The ability to provide users with visualisation and download features for in-situ measurements is seen as a key aspect to start engaging the energy community to share, release and integrate more in-situ measurements. This will put to the test the capacity of cooperation in the SSI community by introducing an unprecedented level of collaboration and eventually help to detect gaps in European earth observation networks. The presentation will be an opportunity to seek further collaboration partners and feedback by the community.

  6. Wonderful Weather

    NSDL National Science Digital Library

    Ms. Broadhead

    2007-11-06

    Second Grade Standard 3: Students will develop an understanding of their environment. Objective 2: Observe and describe weather. Indicator a: Observe and describe patterns of change in weather. Monday November 6th: Look at the five-day forecast for Logan Utah at Five Day Forecast in Utah. The high temperature for the day will be in red and the low temperature will be in blue. Look at the temperature listed in degrees Farenheit (F) not degrees Celcius (C). Make a bar graph for the ...

  7. Weather Forecasting

    NSDL National Science Digital Library

    2010-01-01

    Weather Forecasting is one of several online guides produced by the Weather World 2010 project at the University of Illinois. These guides use multimedia technology and the dynamic capabilities of the web to incorporate text, colorful diagrams, animations, computer simulations, audio, and video to introduce topics and concepts in the atmospheric sciences. This module introduces forecast methods and the numerous factors one must consider when attempting to make an accurate forecast. Sections include forecasting methods for different scenarios, surface features affecting forecasting, forecasting temperatures for day and night, and factors for forecasting precipitation.

  8. Enhancing model-based land surface temperature estimates using multiplatform microwave observations

    NASA Astrophysics Data System (ADS)

    Holmes, Thomas R. H.; Crow, Wade T.; Tugrul Yilmaz, M.; Jackson, Thomas J.; Basara, Jeffrey B.

    2013-01-01

    Land surface temperature plays an important role in surface processes and is a key input for physically based retrieval algorithms of soil moisture and evaporation. This study presents a framework for using independent estimates of land surface temperature from five microwave satellite sensors to improve the accuracy of land surface temperature output from a numerical weather prediction system in an off-line (postprocessing) analysis. First, structural differences in timing and amplitude of the temperature signal were addressed. Then, satellite observations were assimilated into an auto-regressive error model, formulated to estimate errors in the numerical weather prediction output. Errors in daily minimum and amplitude were treated separately. Results of this study provide new insights about potential added benefits of preprocessing and off-line assimilation of microwave remote sensing-based and model-based temperature retrievals. It is shown that the satellite observations may be used to reduce errors in surface temperature, particularly for day-time hours. Preprocessing is responsible for the bulk of this reduction in temperature error; data assimilation is shown to further reduce the random temperature error by a few tenths of a Kelvin, accounting for a 10% reduction in RMSE.

  9. Multilingual Weather Forecast Generation System

    Microsoft Academic Search

    Tianfang Yao; Dongmo Zhang; Qian Wang

    The MLWFA (Multilingual Weather Forecasts Assistant) system will be demonstrated. It is developed to generate the multilingual text of the weather forecasts automatically. The raw data from the weather observation can be used to generate the weather element chart. According to the weather change trend, the forecasters can directly modify the value Of the element on the chart, such as

  10. PV powering a weather station for severe weather

    SciTech Connect

    Young, W. Jr. [Florida Solar Energy Center, Cocoa, FL (United States); Schmidt, J. [Joe Schmidt, Inc., Miami, FL (United States)

    1997-12-31

    A natural disaster, such as Hurricane Andrew, destroys thousands of homes and businesses. The destruction from this storm left thousands of people without communications, potable water, and electrical power. This prompted the Florida Solar Energy Center to study the application of solar electric power for use in disasters. During this same period, volunteers at the Tropical Prediction Center at the National Hurricane Center (NHC), Miami, Florida and the Miami Office of the National Weather Service (NWS) were working to increase the quantity and quality of observations received from home weather stations. Forecasters at NHC have found surface reports from home weather stations a valuable tool in determining the size, strength and course of hurricanes. Home weather stations appear able to record the required information with an adequate level of accuracy. Amateur radio, utilizing the Automatic Packet Report System, (APRS) can be used to transmit this data to weather service offices in virtually real time. Many weather data collecting stations are at remote sites which are not readily serviced by dependable commercial power. Photovoltaic (solar electric) modules generate electricity and when connected to a battery can operate as a stand alone power system. The integration of these components provides an inexpensive standalone system. The system is easy to install, operates automatically and has good communication capabilities. This paper discusses the design criteria, operation, construction and deployment of a prototype solar powered weather station.

  11. Spaceborne weather radar

    Microsoft Academic Search

    Robert Meneghini; Toshiaki Kozu

    1990-01-01

    The present work on the development status of spaceborne weather radar systems and services discusses radar instrument complementarities, the current forms of equations for the characterization of such aspects of weather radar performance as surface and mirror-image returns, polarimetry, and Doppler considerations, and such essential factors in spaceborne weather radar design as frequency selection, scanning modes, and the application of

  12. Seasonal changes in Titan's weather patterns and the evolution and implications of accompanying surface changes

    NASA Astrophysics Data System (ADS)

    Turtle, Elizabeth; McEwen, Alfred

    2012-07-01

    Post-equinox changes in Titan's atmospheric circulation brought clouds and extensive methane rain to low latitudes [1,2]. Observations by Cassini ISS over the ensuing ~1.5 yr revealed surface changes to be short-lived; few rain-darkened areas persisted through 2011. In an unsaturated permeable medium, infiltration rates are >20 mm/week [3], so persistence of surface liquids over several months suggests that either an impermeable layer or the local methane table lies close to the surface. Evaporation rates >1 mm/week are predicted at low latitudes [4] and 20 mm/week has been documented at Titan's poles [5], thus areas where darkening persisted must be saturated ground at the level of a methane table or have had ponded liquid 2.5-50 cm deep. Several smaller areas of surface brightening were also observed, a phenomenon that is less well understood. Cassini VIMS spectra of these regions do not match clouds or other surface units [6]. Interpretations include cleaning by runoff [2] or deposition of a fine-grained volatile solid as the result of evaporative cooling of the surface [6]. In general, brightening has persisted longer than darkening, but these areas are also reverting to their original appearance, possibly due to evaporation/sublimation of the bright material or re-deposition of darker hydrocarbons by aeolian transport or precipitation from the atmosphere. Cassini and Earth-based observers monitor Titan frequently, but few clouds have been observed since Fall 2010, which may indicate that enough methane was removed from the atmosphere and the lapse rate stabilized sufficiently that activity will not resume until the onset of convection at mid-northern latitudes later in northern spring. A similar lapse followed a 2004 outburst of south-polar clouds [7], which also appeared to produce significant rainfall [8]. [1] Turtle et al., GRL 38, L03203, doi:10.1029/2010GL046266, 2011. [2] Turtle et al., Science 331, 10.1126/science.1201063. 2011. [3] Hayes et al., GRL 35, L09204, 2008. [4] Schneider et al., Nature 481, doi:10.1038/nature10666, 2012. [5] Hayes et al., Icarus 211, 2011. [6] Barnes et al., LPSC XXXXIII, 2012. [7] Schaller et al., Icarus 184, 2006. [8] Turtle et al., GRL 36, L02204, doi:10.1029/2008GL036186, 2009.

  13. Monitoring land surface fluxes using ASTER observations

    Microsoft Academic Search

    Thomas J. Schmugge; William P. Kustas; Karen S. Humes

    1998-01-01

    This paper presents a review of methods for using remotely sensed data from the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) to estimate the energy fluxes from the land surface. The basic concepts of the energy balance at the land surface are presented along with an example of how remotely sensed surface brightness temperatures can be used to estimate

  14. Cloud Observation and Modeling Test Bed for Air Force Weather Applications: Overview and First Results

    NASA Astrophysics Data System (ADS)

    Nobis, T. E.

    2012-12-01

    Air Force Weather (AFW) has documented requirements for real-time cloud analysis and short range cloud forecasts to support DoD missions around the world. To meet these needs, AFW utilizes the Cloud Depiction and Forecast System (CDFS) II system to develop a hourly cloud analysis and short range forecast. The system creates cloud masks from 16 different satellite sources and optimally merges them to create the analysis. This analysis then forms the initialization field for a short range 'advective' based cloud forecast. Northrop Grumman Corp. has recently delivered a CDFS II based Cloud Model Test Bed. This system offers the ability to test several aspects of the CDFS II system including: the effect of adding and subtracting sources of cloud imagery, the effect of changing source and skill of required external data sources, and the impact of changing the cloud information merge process among the various sources. In addition, the test bed offers a capability to generate a robust cloud modeling baseline against which to measure progress of a next generation Numerical Weather Prediction (NWP) based advanced data assimilation system. Finally, the test bed allows the development and testing of new cloud modeling validation techniques (and sources) to provide greater confidence in results generated from the test bed. This presentation will provide a basic overview of the CDFS II system and of the newly developed Test Bed and will include results from the first series of experiments conducted using the Test Bed.

  15. Seasonal changes in Titan's weather patterns and the evolution and implications of accompanying surface changes

    NASA Astrophysics Data System (ADS)

    Turtle, E. P.; Perry, J.; McEwen, A. S.; Barbara, J. M.; Del Genio, A. D.; West, R. A.; Barnes, J. W.; Hayes, A.; Lorenz, R. D.; Lunine, J. I.; Stofan, E. R.; Schaller, E. L.; Lopes, R. M.; Ray, T. L.

    2012-12-01

    Post-equinox changes in Titan's atmospheric circulation brought clouds and extensive methane rain to Titan's low latitudes [1,2]. Observations by Cassini ISS over the ~2 years since the storm revealed most of the changes to be short-lived; only a few darkened patches persisted through Fall 2011. In an unsaturated permeable medium, infiltration rates exceed 20 mm/week [3], so persistence of surface liquids over several months suggests either a shallow impermeable layer or that the local methane table lies close to the surface. Evaporation rates greater than 1 mm/week are predicted in equatorial regions [4] and rates of 20 mm/week have been documented at Titan's poles [5], thus areas where darkening persisted must be saturated ground at the level of a methane table or have had liquid ponded to depths of 2.5-50 cm. Several smaller areas of surface brightening were also observed, a phenomenon that is less well understood. Cassini VIMS spectra of these regions do not match those of clouds or other surface units [6, 7]. Interpretations include cleaning by runoff [2] or deposition of a fine-grained volatile solid as the result of evaporative cooling [6, 7]. In general, brightening has persisted longer than darkening, but these areas are also reverting to their original appearance, which could constrain rates of evaporation/sublimation of the bright material or re-deposition of darker hydrocarbons by aeolian transport or precipitation from the atmosphere. Cassini and Earth-based observers monitor Titan frequently (typically at least a few times per month), but few clouds have been observed since Fall 2010, which may indicate that enough methane was removed from the atmosphere and the lapse rate stabilized sufficiently that activity will not resume until the onset of convection at mid-northern latitudes later in northern spring. A similar lapse followed a 2004 outburst of south-polar clouds [8], which also appeared to produce significant rainfall [9]. [1] Turtle et al., GRL 38, L03203, doi:10.1029/2010GL046266, 2011. [2] Turtle et al., Science 331, 10.1126/science.1201063. 2011. [3] Hayes et al., GRL 35, L09204, 2008. [4] Schneider et al., Nature 481, doi:10.1038/nature10666, 2012. [5] Hayes et al., Icarus 211, 2011. [6] Barnes et al., LPSC XXXXIII, 2012. [7] Barnes et al., in revision. [8] Schaller et al., Icarus 184, 2006. [9] Turtle et al., GRL 36, L02204, doi:10.1029/2008GL036186, 2009.

  16. Space Weather Monitoring for ISS Space Environments Engineering and Crew Auroral Observations

    NASA Astrophysics Data System (ADS)

    Minow, J. I.; Pettit, D. R.; Hartman, W. A.

    2012-12-01

    The International Space Station (ISS) space environments community utilizes near real time space weather data in support of a variety of ISS engineering and operations activities. The team has operated the Floating Potential Measurement Unit (FPMU) suite of plasma instruments (two Langmuir probes, a floating potential probe, and a plasma impedance probe) on ISS from 2006 to the present time to obtain in-situ measurements of plasma density and temperature along the ISS orbit and variations in ISS frame potential due to the combined effects of electrostatic current collection processes from the plasma environment and inductive (vxB) effects due to the motion of the vehicle across the Earth's magnetic field. An ongoing effort to use FPMU for measuring the ionospheric response to geomagnetic storms at ISS altitudes and document ISS frame charging as the vehicle passes through regions of precipitating auroral electrons is challenged by restrictions on the available FPMU operation time. The instruments can only be operated during campaign periods limited to about a third of a year in accumulated operation time and FPMU data is down linked through the ISS Ku band telemetry system, a shared resource. As a result, FPMU campaign periods of a few days to weeks have typically been scheduled for periods of a week or two in advance. Capturing geomagnetic storm data under these conditions depended on the fortuitous event of a storm starting during a previously planned FPMU campaign period, an unlikely event at a time when Solar Cycle 24 was ending and a protracted solar minimum gave little in the way of geoeffective solar disturbances. However, with the start of Solar Cycle 24 the number of solar disturbances and associated geomagnetic storms started to increase and we modified our strategy to improve the chances of capturing geomagnetic storm data. We now monitor near real time space weather data from NASA, NOAA, and ESA sources to determine solar wind disturbance arrival times at Earth likely to be geoeffective (including coronal mass ejections and high speed streams associated with coronal holes) and activate the FPMU ahead of the storm onset. Using this technique we have now been successful in capturing FPMU records from a number of geomagnetic storm periods including variations in ISS frame potential at high latitudes associated with geomagnetic activity that we interpret as auroral charging. In addition, space weather summaries were provided to ISS Expedition 30/31 crew along with predictions for upcoming auroral activity and estimates for times the ISS orbit would pass through regions of high magnetic latitude to enhance crew opportunities to image aurora from the ISS. This presentation will describe the near real time space weather resources utilized to predict FPMU operation times, summarize the results from FPMU operations during the geomagnetic storm periods, and provide examples of auroral images obtained by the ISS crew during recent storm periods from the spring and summer of 2012.

  17. Twenty years of weather and observing statistics in San Pedro Mártir, Baja California Mexico

    NASA Astrophysics Data System (ADS)

    Tapia, M.

    2003-09-01

    Statistics are presented covering 20 years of use of the 2.1m telescope of the Observatorio Astronómico Nacional at San Pedro Mártir, Baja California, Mexico. As in the previous compilation, the fractional number of nights with totally clear, partially clear and mostly cloudy skies were determined. The fraction of nights lost due to bad weather was 22.2% in the period July 1982 to December 2002. From January 1984 to December 2002, 63.1% of the nights were of ``photometric'' quality and 80.8% were of ``spectroscopic'' quality. During the past seven years of ``drought'' in the area, the fraction of photometric quality nights increased to 73.5%, but the fraction of spectroscopic nights remained similar to previous years. The figures are similar to those reported for the Chilean sites and are better than those for Northern Hemisphere observatories.

  18. Identification of weathered structures and aquifers from resistivity observations in the Strengbach catchment (Vosges, France).

    NASA Astrophysics Data System (ADS)

    Gance, Julien; Sailhac, Pascal; Malet, Jean-Philippe; Viville, Daniel; Pierret, Marie-Claire

    2015-04-01

    In low mountain regions, natural water resources used for agriculture or drinking water generally come from natural sources. Management of these water resources is complex for some catchments where most of the water flows is exfiltrating from bedrock aquifers characterized by important spatial heterogeneity and different connectivity levels in space and time. The Strengbach catchment (Vosges, North East France) is a hydro-geochemical observatory monitored for more than 25 years. The numerous geochemical studies have highlighted the existence of different lithological and structural units in the catchment constituted by different weathered granitic aquifers. Their spatial extension has been determined through the measurement of the soil electrical resistivity using 20 Electrical Resistivity Tomography (ERT) profiles. The profiles have been inverted separately with the BERT software in 2D and compared to 2.5 D inversions, where the inversion accounts for the profile crossings. The comparison between 2D and 2.5D inversion results allows validating the 2-D assumption. The 20 profiles are distributed over the complete catchment and cover more densely the water source area of the Strengbach stream. The shallow resistivities (5-10 m) measured highlight several weathered zones possibly characterized by different porosity. A combined analysis with soil water conductivity measurements in boreholes allows proposing a map of the spatial extension of these units. The resistivity data are also used to assess the depth of the main reservoir at the scale of the catchment. The hypothesis of the existence of a deeper reservoir is brought out by Audio-Magneto Telluric (AMT) and Very Low Frequency (VLF) measurements.

  19. Optimizing next-generation operational observation networks for the short-term forecast of Mediterranean high-impact weather

    NASA Astrophysics Data System (ADS)

    Garcies Artigues, L.; Homar Santaner, V.

    2010-09-01

    Weather forecasting authorities are perceiving increasing pressure from the public to extend and improve the quality of short-range predictions while reducing costs and increasing the overall forecasting efficiency. The European community is strongly committed to attain this increased efficiency by focusing on the observational component of the weather forecasting process. One important research commitment is oriented to optimize the integrated observing system networks to achieve better representations of the atmosphere and eventually more accurate forecasts. In this context, sensitivity analysis techniques aim at identifying causal atmospheric structures that have a relevant effect on a particular aspect of interest, such as strong winds or heavy rains. Indeed, information derived from such sensitivity analysis should be the guiding basis for decision makers to focus on areas where an increased observational effort would significantly improve the quality and value of short-range numerical weather predictions across the region. Although several sensitivity calculation techniques exist that aim at computing the relevant areas for a particular weather event -such as those used in real-time targeting campaigns- permanent redesigns of the observational strategies require climatological sensitivity information. However, no consensus exists on how climatological sensitivity information should be derived or even verified in a relevant and useful way. The aim of this work is twofold, on the one side, the essential results from 3 sensitivity climatologies (an adjoint-based and two different ensemble-based) for the short-range prediction of Mediterranean intense cyclones are presented. On the other hand, a verification testbed to evaluate and compare the skill of each climatological sensitivity estimate is developed. The verification of these climatologies is essential to ensure the reliability of the sensitivity products and ultimately provide robust guidance to policy-makers on plans to redefine routine observational strategies. We propose the use of Observing System Simulation Experiments to quantify the reliability of the available adjoint and ensemble sensitivity climatologies. In particular, verification experiments with the NCAR Advanced Research WRF ARW model are conducted for the 25 most intense Mediterranean cyclones of the ERA-40 database to test the ability of each method in identifying areas where perturbations in the initial conditions derived from the sensitivity fields lead to a greater impact on the forecast of the intense cyclone. For the sake of calibration of the verification results, the performance of the sensitivity climatologies is tested against a reference sensitivity proxy consisting of the judgement of an experienced severe weather meteorologist who was asked to indicate the region where a perturbation in the initial conditions would have the largest impact on the forecasted cyclone's depth. Our results reveal the significantly superior skill of the human and adjoint sensitivity fields against both climatological ensemble sensitivity methods. Also, an optimized ensemble sensitivity climatology based on an ad hoc classification of Mediterranean intense cyclones show a moderate advantage over the previous ensemble sensitivity version.

  20. Evolution of Titan's equinoctial weather patterns and accompanying surface changes and implications thereof

    NASA Astrophysics Data System (ADS)

    Turtle, E. P.; Perry, J. E.; Barnes, J. W.; McEwen, A. S.; Barbara, J. M.; Del Genio, A. D.; Hayes, A. G.; West, R. A.; Lorenz, R. D.; Schaller, E. L.; Lunine, J. I.; Ray, T. L.; Lopes, R. M. C.; Stofan, E. R.

    2012-04-01

    Post-equinox changes in Titan's atmospheric circulation brought clouds and extensive methane rain to Titan's low latitudes [1,2]. Observations by Cassini ISS over the ~1.5 years since the storm revealed most of the changes to be short-lived; only a few darkened patches persisted through Fall 2011. In an unsaturated permeable medium, infiltration rates are >20 mm/week [3], so persistence of surface liquids over several months suggests either a shallow impermeable layer or that the local methane table lies close to the surface. Evaporation rates >1 mm/week are predicted in equatorial regions [4] and rates of 20 mm/week have been documented at the poles [5], thus areas where darkening persisted must be saturated ground at the level of a methane table or have had liquid ponded to depths of 2.5-50 cm. Several smaller areas of surface brightening were also observed, a phenomenon that is less well understood. Cassini VIMS spectra of these regions do not match those of clouds or other surface units [6, 7]. Interpretations include cleaning by runoff [2] or deposition of fresh methane ice [6, 7]. In general, brightening has persisted longer than darkening, but these areas are also reverting to their original appearance, which could constrain the rate of re-deposition of darker hydrocarbon materials by aeolian transport or possibly precipitation of aerosols from the atmosphere. Although we monitor Titan frequently (at least a few times per month), little cloud activity has been observed since Fall 2010. This lack of clouds may indicate that the outbreak removed enough methane from the atmosphere and the lapse rate stabilized sufficiently that activity will not resume until the onset of convection at mid-northern latitudes later in northern spring. A similar lapse followed a large outbreak of south-polar clouds in Fall 2004 [8], which also appeared to produce significant rainfall [9]. References: [1] Turtle et al., GRL 38, L03203, doi: 10.1029/2010GL046266, 2011. [2] Turtle et al., Science 331, p. 1414, 10.1126/science.1201063. 2011. [3] Hayes et al., GRL 35, L09204, 2008. [4] Schneider et al., Nature 481, doi:10.1038/nature10666, 2012. [5] Hayes et al., Icarus 211, p. 655, 2011. [6] Barnes et al., LPSC XXXXIII, 2012. [7] Barnes et al., Titan Through Time, 3-5 April 2012. [8] Schaller et al., Icarus 184, p. 517, 2006. [9] Turtle et al., GRL 36, L02204, doi:10.1029/ 2008GL036186, 2009.

  1. Geography & Weather. Weather Mapping.

    ERIC Educational Resources Information Center

    Mogil, H. Michael; Levine, Barbara G.

    1990-01-01

    Presented are 35 activities that center around television and newspaper weather reports. Geography, weather, and other disciplines are included as well as various grade levels. Available resource materials are listed and their uses explained. Parent, administrator, and other faculty member involvement is emphasized. (KR)

  2. Thermophysics During the MER Spirit Winter Campaign: Observing Complex Surfaces Through Seasonal and Diurnal Cycles

    NASA Astrophysics Data System (ADS)

    Fergason, R. L.; Christensen, P. R.; Arvidson, R. E.

    2006-12-01

    In this work, we quantify the response of surface temperature to subsurface layers, local weather variations, and seasonal processes at the MER Spirit landing site region. Previous thermophysical work at the MER landing sites include deriving thermal inertia values of dusty, sandy, and rocky surfaces, and comparing the thermally derived particle size with those measured directly using Pancam and MI images (1). We have designed observations that build on these previous results and take advantage of the unique opportunity to measure surface phenomena that require longer experiment durations as the winter power constraints reduce the mobility of the MER Spirit. Three thermophysical experiments using Mini-TES have been performed: 1) deriving the thermal inertia above and below a layered outcrop; 2) measuring the day-to-day variability in surface temperature; and 3) observing the seasonal temperature profile. First, we measured the diurnal temperature curve above and below an exposed layered outcrop to derive thermal inertia values. These results allow a more complete understanding of the effect of layers on surface temperature and thermal inertia, which can then be applied to the interpretation of orbital data (2). Preliminary results suggest that the thermal inertia of the surface below the outcrop is best defined by a mixture of rock (35%) and sand (65%), and corresponds to the heterogeneous surface observed in Pancam images. The surface above the outcrop is best fit by a thermal inertia of 600, and is dominated by the subsurface layered material. In addition, the temperature of the surface was measured at the same time each day for 15 sols to quantify typical surface temperature variations due to local weather on Mars. Preliminarily, surface temperatures at the Spirit site vary by an average of 3 K, and this knowledge is important for identifying thermal anomalies in THEMIS infrared images. Finally, measuring the surface temperature for many months allows us to measure the effects of material deeper in the subsurface on surface temperature. Preliminary results suggest that the thermal model adequately accounts for seasonal variations and also implies that there is no subsurface structure tens of centimeters from the surface complicating these measurements. References. (1) R. L. Fergason et al., J. Geophys. Res., 111, 10.1029/2005JE002583(2006); (2) N. E. Putzig, M. T.Mellon, LPSC XXXVII, Abs. 2316 (2006).

  3. Putting Weather into Weather Derivatives

    NASA Astrophysics Data System (ADS)

    Smith, L. A.; Smith, L. A.

    2001-12-01

    Just as weather forecasting has a colorful and often farsighted history within geophysics, financial mathematics has a long and turbulent history within mathematics. Thus it is no surprise that the intersection of real physics and real financial mathematics provides a rich source of problems and insight in both fields. This presentation targets open questions in one such intersection: quantifying ``weather risk.'' There is no accepted (operational) method for including deterministic information from simulation models (numerical weather forecasts, either best guess or by ensemble forecasting methods), into the stochastic framework most common within financial mathematics. Nor is there a stochastic method for constructing weather surrogates which has been proven successful in application. Inasmuch as the duration of employable observations is short, methods of melding short term, medium-range and long term forecasts are needed. On these time scales, model error is a substantial problem, while many methods of traditional statistical practice are simply inappropriate given our physical understanding of the system. A number of specific open questions, along with a smaller number of potential solutions, will be presented. >http://www.maths.ox.ac.uk/~lenny/WeatherRisk

  4. Observation of surface states with algebraic localization.

    PubMed

    Corrielli, G; Della Valle, G; Crespi, A; Osellame, R; Longhi, S

    2013-11-27

    We introduce and experimentally demonstrate a class of surface bound states with algebraic decay in a one-dimensional tight-binding lattice. Such states have an energy embedded in the spectrum of scattered states and are structurally stable against perturbations of lattice parameters. Experimental demonstration of surface states with algebraic localization is presented in an array of evanescently coupled optical waveguides with tailored coupling rates. PMID:24329428

  5. Space Weathering of Rocks

    NASA Technical Reports Server (NTRS)

    Noble, Sarah

    2011-01-01

    Space weathering discussions have generally centered around soils but exposed rocks will also incur the effects of weathering. On the Moon, rocks make up only a very small percentage of the exposed surface and areas where rocks are exposed, like central peaks, are often among the least space weathered regions we find in remote sensing data. However, our studies of weathered Ap 17 rocks 76015 and 76237 show that significant amounts of weathering products can build up on rock surfaces. Because rocks have much longer surface lifetimes than an individual soil grain, and thus record a longer history of exposure, we can study these products to gain a deeper perspective on the weathering process and better assess the relative impo!1ance of various weathering components on the Moon. In contrast to the lunar case, on small asteroids, like Itokowa, rocks make up a large fraction of the exposed surface. Results from the Hayabusa spacecraft at Itokowa suggest that while the low gravity does not allow for the development of a mature regolith, weathering patinas can and do develop on rock surfaces, in fact, the rocky surfaces were seen to be darker and appear spectrally more weathered than regions with finer materials. To explore how weathering of asteroidal rocks may differ from lunar, a set of ordinary chondrite meteorites (H, L, and LL) which have been subjected to artificial space weathering by nanopulse laser were examined by TEM. NpFe(sup 0) bearing glasses were ubiquitous in both the naturally-weathered lunar and the artificially-weathered meteorite samples.

  6. Climatological weather observations Rainfall records at the University date back to 1901, with comprehensive

    E-print Network

    Matthews, Adrian

    and the lower atmosphere, the surface energy balance, measurements and instruments. It gives students and research, particularly concerned with study of the energy and momentum exchange between the surface for the detection of acoustic waves that propagate through the stratosphere. Research Research equipment can

  7. Tracking tropical cloud systems - Observations for the diagnosis of simulations by the Weather Research and Forecasting (WRF) Model

    SciTech Connect

    Vogelmann, A.M.; Lin, W.; Cialella, A.; Luke, E.; Jensen, M.; Zhang, M.

    2010-03-15

    To aid in improving model parameterizations of clouds and convection, we examine the capability of models, using explicit convection, to simulate the life cycle of tropical cloud systems in the vicinity of the ARM Tropical Western Pacific sites. The cloud life cycle is determined using a satellite cloud tracking algorithm (Boer and Ramanathan, 1997), and the statistics are compared to those of simulations using the Weather Research and Forecasting (WRF) Model. Using New York Blue, a Blue Gene/L supercomputer that is co-operated by Brookhaven and Stony Brook, simulations are run at a resolution comparable to the observations. Initial results suggest a computational paradox where, even though the size of the simulated systems are about half of that observed, their longevities are still similar. The explanation for this seeming incongruity will be explored.

  8. Weathering of iron sulfides and concrete alteration: Thermodynamic model and observation in dams from central Pyrenees, Spain

    SciTech Connect

    Ayora, C. [Inst. de Ciencias de la Tierra, Barcelona (Spain)] [Inst. de Ciencias de la Tierra, Barcelona (Spain); Chinchon, S. [Univ. de Alicante (Spain). Dept. de Construcciones Arquitectonicas] [Univ. de Alicante (Spain). Dept. de Construcciones Arquitectonicas; Aguado, A.; Guirado, F. [Univ. Politecnica de Catalunya (Spain). Dept. de Ingenieria de la Construccion] [Univ. Politecnica de Catalunya (Spain). Dept. de Ingenieria de la Construccion

    1998-04-01

    The concrete of the Graus and Tabescan dams present significant durability problems. The cement paste is altered to expansive phases such as ettringite and gypsum, following fractures and aggregate-paste interfaces. The alteration is initially attributed to the acidic solution produced by the weathering of the pyrrhotite contained in the aggregate fragments. A chemical model, based on ion association and thermodynamic equilibrium, permits the calculation of the mass transfer between the solids and the pore solution, and the prediction of the progress of the acidic attack. The results of the calculations have been compared with the alteration features observed in concrete of these dams. Despite the simplifications, this model is able to predict the observed alteration stages, and confirms the hypothesis of acidic-sulfatic alteration of the cement.

  9. Microbial control of mineral weathering kinetics

    SciTech Connect

    Bennett, P.C.; Hiebert, F.K. [Univ. of Texas, Austin, TX (United States)

    1995-12-01

    The influence of native microorganisms on mineral dissolution and precipitation kinetics was examined in a petroleum contaminated aquifer. In situ microcosms containing clean mineral fragments (calcite, dolomite, quartz, albite, microcline, anorthite, muscovite, biotite) were allowed to colonize and react over 1 year periods, and the surfaces then examined for microbial colonization patterns and weathering features. These experiments revealed distinct patterns of colonization, and weathering associated with microbial metabolism. Feldspar surfaces were widely colonized, and the colonized surfaces were deeply weathered, while secondary clays precipitated on uncolonized surfaces. Calcite surfaces were sparsely colonized, but deeply pitted around microbial colonies. Distinctive precipitation features were otherwise observed on all other surfaces, with overgrowth morphology related to crystal orientation. The rates of calcite dissolution was directly controlled at the microscopic level by microbial activity around colonies, while precipitation rate is probably related to microbial perturbation of the meso-scale inorganic geochemistry, and may be limited by dolomite dissolution rate.

  10. Using shallow seismic tomography to characterize patterns of near-surface weathering and the mobile-immobile regolith transition: Implications for the erodibility and morphology of hillslopes.

    NASA Astrophysics Data System (ADS)

    Clarke, B. A.; Kirby, E.; Burbank, D. W.; West, N.

    2014-12-01

    We use 2D tomography of P- and S-wave velocities (Vp, Vs), based on seismic refraction and surface wave analyses, to characterize subsurface architecture and erodibility of hillslopes. Calibrating the seismic imagery with direct field observations allows us to quantify mechanical properties, image depth-dependent variations in weathering intensity, and identify the mobile-immobile regolith transition and differences in transport efficiency of mobile layers. We conducted a cross-CZO comparison of N- and S-facing slopes at Boulder Creek and Shale Hills CZOs (BcCZO and SSHCZO) to investigate how near-surface weathering and hillslope morphology are influenced by differences in regional geology and climatic as well as local variations in aspect-controlled microclimate. Niwot Ridge (BcCZO) is a high alpine site with minimal soil/veg cover, characterized by steeper S-facing hillslopes; whereas, SSHCZO is a temperate, densely-forested, soil-mantled site with steeper N-facing slopes. On Niwot Ridge, the depth of the weathering front and thickness of mobile regolith are substantially greater on shallower N-facing slopes; however, velocity-based estimates of transport efficiency are higher on S-facing slopes. Although, thin mobile regolith on S-facing slopes may be weaker (slower V), the lower gradient of N-facing slopes and southward asymmetry of the ridge divide, suggests greater transport efficiency on N-facing aspects. This can be explained by the dominance of frost/freeze process on N-facing slopes, which can efficiently develop and transport the thick mobile regolith. At SSHCZO, depths of weathering fronts are invariant with slope aspect, suggesting that aspect control is not a predominant mechanism driving regolith production. Mobile regolith thickness, however, is more than 2-fold greater on N-facing slopes. Additionally, mobile regolith on both slope aspects is primarily composed of well-developed soils. N-facing soils are thicker with greater cohesion, moisture, and inclusion of rock fragments. This is consistent with velocity-based estimates of lower transport efficiency on N-facing slopes relative to the thin, dry, fine grained soils on S-facing slopes.

  11. Vertical structure of the wind field during the Special Observing Period I of the Global Weather Experiment

    NASA Technical Reports Server (NTRS)

    Paegle, J. N.; Paegle, J.; Zhen, Z.; Sampson, G.

    1986-01-01

    The vertical structure of the global atmosphere is analyzed for selected periods of the Special Observing Period I (SOP-I) for the Global Weather Experiment (GWE). The analysis consists of projection of the stream-function and velocity potential at 200 and 850 mb on spherical harmonics and of the wind and height fields on the normal modes of a linearized form of the primitive equations for a basic state at rest. The kinematic vertical structure is discussed in terms of correlation coefficients of the 200 mb and 850 mb winds and analysis of the internal and external normal modes of the primitive equations. The reliability of the results is checked by applying the same analysis methods to data sets obtained from three different institutions: Geophysical Fluid Dynamics Laboratory (GFDL), European Center for Medium Range Weather Forecasting (ECMWF), and Goddard Laboratory for the Atmospheres (GLA). It is found that, on a global basis, vertically reversing circulations are as important as the equivalent barotropic structures. For the verticaly reversing components, the gravity and mixed Rossby-gravity modes have contributions of the same order of magnitude as those of the Rossby modes in tropical latitudes.

  12. An assessment of surface soil temperature products from numerical weather prediction models using ground-based measurements

    NASA Astrophysics Data System (ADS)

    Holmes, Thomas R. H.; Jackson, Thomas J.; Reichle, Rolf H.; Basara, Jeffrey B.

    2012-02-01

    Surface soil temperature estimates at approximately 0.05 m depth are needed to retrieve soil moisture from the planned Soil Moisture Active Passive (SMAP) L-band (1.4 GHz) satellite. Numerical weather prediction (NWP) systems as operated by various weather centers produce global estimates of soil temperature. In this study in situ data collected over the state of Oklahoma are used to assess surface (soil) temperature from three NWP systems: (1) the integrated forecast system from the European Center for Medium range Weather Forecasts (ECMWF), (2) the modern-era retrospective analysis for research and applications (MERRA) from the NASA Global Modeling and Assimilation Office, and (3) the global data assimilation system used by the National Center for Environmental Prediction (NCEP). The results are presented by hour of day with specific attention directed to the SMAP early morning overpass time at around 6 A.M. local time, and the period of 1 April to 1 October 2009. It was found that the NWP systems estimate the 0.05 m soil temperature at this time of day with an overall root mean square error of 1.9 to 2.0 K. It is shown that this error can be reduced to 1.6 to 1.8 K when differences between the modeling and measurement depth are accounted for by synchronizing each NWP set to match the mean phase of the in situ data and adjusting the amplitude in accordance with heat flow principles. These results indicate that with little calibration all products meet the SMAP error budget criteria over Oklahoma.

  13. Space-time variation of the Typhoon Morkat (2009) rainband structure over Taiwan's complex terrain observed by weather radars and rain gauge measurements

    NASA Astrophysics Data System (ADS)

    Liou, Yu-Chieng; Wang, Tai-Chi Chen; Tsai, Yi-Chun; Tang, Yu-Shuang

    2013-04-01

    This research studies the structure of precipitation systems over Taiwan as Typhoon Morakot (2009) impinged on the island on 8 August 2009 using data observed by weather radars and rain gauges. A newly-designed multiple-Doppler radar synthesis technique particularly designed for dealing with non-flat surfaces is applied to analyze the three-dimensional wind fields over the ocean and terrain. In the northern and southern portion of the analysis domain where the mountain slope is relatively gentle and steep, respectively, the radar reflectivity measurements indicate that the precipitation systems exhibit horizontal translation in the north and abrupt intensification in the south. Far from the southern mountainous region, a north-south oscillation of an east-west-oriented band of strong radar reflectivity (>40 dBZ) with a horizontal span of 20 km is observed. Along the mountain slopes, the region of strong radar reflectivity expands to a much wider north-south-oriented area. The major precipitation is confined to the windward side of the mountains. Further analysis reveals that the upstream atmosphere is statically unstable, which implies that the lifting of the incoming convective cells by the topography will easily trigger precipitation. Thus, most of the moisture will be consumed before the air reaches the leeward side of the mountains. The long duration and the wide range of heavy precipitation in the mountainous regions resulted in a record-breaking rainfall amount of 2,000 mm over four days. A noticeable feature of the prevailing westerly flow is a wind speed maximum (~ 40 m s-1) above the mountain crest, which can be explained by a simplified shallow water model. The capability of applying the weather radar to provide a reliable quantitative estimate of the rainfall over a large area with high temporal and spatial resolution is shown using dual-polarimetric radar data. Our results demonstrate the potential applications of the knowledge of the wind and precipitation characteristics in hydrology and other related fields.

  14. Age calibration of weathering fractures in desert clasts: A new approach to dating geomorphic surfaces in arid landscapes

    NASA Astrophysics Data System (ADS)

    D'Arcy, Mitch; Roda Boluda, Duna; Whittaker, Alex

    2014-05-01

    Advances in geomorphological and sedimentological research depend on the availability of reliable exposure age constraints. Establishing robust age models at a high spatial and temporal resolution is crucial for measuring rates of geomorphological change and decoding complex landscapes shaped by time-dependent forces, e.g. climate fluctuations. A number of isotopic and luminescence techniques are now available for dating geomorphic surfaces, however they remain expensive and time-consuming to deploy with detailed coverage over space and time in many study areas. For this reason, quick and accessible methods for correlating and extrapolating these chronologies are needed. In arid landscapes, among others, a variety of weathering-induced changes occur to geomorphic and sedimentary surfaces, and many of these processes occur at predictable rates and can be quantified using objective, field based measurements. One example is the gradual widening of fractures that exist within boulders on desert surfaces, by a combination of processes including salt weathering and freeze-thaw cycles. The recent emergence of very detailed exposure age models in a number of locations means it is now possible to measure the rates of desert weathering processes, and use them as fully calibrated age indicators themselves. With the potential to significantly extend the coverage of existing age constraints, this kind of quantitative age correlation would enable a broad range of geomorphological and sedimentological research that depends on detailed absolute age models. We have measured the mean widths of hundreds of vertical fractures that dissect granitic boulders, on a variety of alluvial surfaces in Owens Valley, California, which have themselves been independently dated in detail using cosmogenic nuclides. Our data demonstrates for the first time that these fractures widen at a predictable, steady rate of approximately 1 mm ka-1 for at least the last 150 ka, in this arid study area in the south-western United States. This finding, which is repeatable at a number of test sites, allows clast fracture widths to be exploited as a simple and powerful technique for the inexpensive dating of geomorphic surfaces in the field. We introduce a robust statistical method for this new approach to exposure dating, perform a full uncertainty analysis on its results, and discuss the potential usefulness of this technique in other arid landscapes.

  15. U. S. -Weather Bureau. Hurricane Esther, surface charts for 6 hourly

    E-print Network

    SURFACE CHART 122, September 19, 1961 #12;ESTHER 500 NIB. CHART 122, September 19 ,1961 #12;SURFACE CHART 18Z, September 19 1961ESTHER #12;500 NIB. CHART ESTHER OOZ, September 20 ,1961 #12;ESTHER SURFACE. CHART #12;ESTHER SURFACE CHART 182, September 24, 1961 #12;500 NIB. CHART ESTHER OOZ,September 25 ,1961

  16. Weather Forecasting

    NSDL National Science Digital Library

    This activity is designed to give students an understanding of how to forecast weather and how to use weather reports for their personal benefit. They will be able to tell what weather is, read weather instruments, understand basic cloud formations in relation to the weather, and make forecasts for two days in advance.

  17. Vertical transport of surface fire emissions observed Siegfried Gonzi1

    E-print Network

    Palmer, Paul

    Vertical transport of surface fire emissions observed from space Siegfried Gonzi1 and Paul I, respectively. Citation: Gonzi, S., and P. I. Palmer (2010), Vertical transport of surface fire emissions estimation to infer the vertical distribution of surface emissions lofted from boreal and tropical biomass

  18. Plasmon switching: Observation of dynamic surface plasmon steering by

    E-print Network

    Paris-Sud XI, Université de

    Plasmon switching: Observation of dynamic surface plasmon steering by selective mode excitation a plasmon steering method that enables us to dynamically control the direction of surface plasmons generated surface plasmons are launched can be controlled. Experiments confirm that it is possible to distribute

  19. Plasmon Surface Polariton Dispersion by Direct Optical Observation.

    ERIC Educational Resources Information Center

    Swalen, J. D.; And Others

    1980-01-01

    Describes several simple experiments that can be used to observe directly the dispersion curve of plasmon surface polaritons (PSP) on flat metal surfaces. A method is described of observing the increonental change in the wave vector of the PSP due to coatings that differ in thickness by a few nanometers. (Author/CS)

  20. EVALUATION OF PARAMETERIZED SURFACE FLUXES WITH ARM OBSERVATIONS

    E-print Network

    EVALUATION OF PARAMETERIZED SURFACE FLUXES WITH ARM OBSERVATIONS G. Liu, Y. Liu, T. Toto, M. Jensen advantage of the long-term observations of surface fluxes collected by the DOE ARM program at the Great the ARM measurements based on the EC (Eddy- Correlation) and EBBR (Energy Balance Bowen Ratio) methods

  1. Observed and CAM3 GCM Sea Surface Wind

    E-print Network

    Zender, Charles

    Observed and CAM3 GCM Sea Surface Wind Speed Distributions: Characterization, Comparison, and Bias climatological surface wind speed probability density functions (PDFs) estimated from observations and use them to evaluate, for the first time, contemporaneous wind PDFs predicted by a GCM. The ob- servations include NASA

  2. A statistical model for road surface friction forecasting applying optical road weather measurements

    Microsoft Academic Search

    M. Hippi; I. Juga; P. Nurmi

    2009-01-01

    Road surface friction is defined as the grip between car tyre and underlying surface. Poor friction often plays a crucial role in wintertime car accidents. Friction can decrease dramatically during snowfall or when wet road surface temperature falls below zero. Even a thin layer of ice or snow can decrease friction substantially increasing the risk of accidents. Many studies have

  3. NOAA Daily Weather Maps

    NSDL National Science Digital Library

    Hydrometeorological Prediction Center

    2011-01-01

    The charts on this website are the principal charts of the former Weather Bureau publication, "Daily Weather Map." They are the Surface Weather Map, the 500-Millibar Height Contours chart, the Highest and Lowest Temperatures chart, and the Precipitation Areas and Amounts chart. For each day, simple charts are arranged on a single page. These charts are the surface analysis of pressure and fronts, color shading, in ten degree intervals,of maximum and minimum temperature, 500-Millibar height contours, and color shaded 24-hour total precipitation. These charts act as links to their respective Daily Weather Map charts. All charts are derived from the operational weather maps prepared at the National Centers for Environmental Prediction, Hydrometeorological Prediction Center, National Weather Service.

  4. Weather Watch

    ERIC Educational Resources Information Center

    Bratt, Herschell Marvin

    1973-01-01

    Suggests a number of ways in which Federal Aviation Agency weather report printouts can be used in teaching the weather section of meteorology. These weather sequence reports can be obtained free of charge at most major airports. (JR)

  5. Weather Vane

    NSDL National Science Digital Library

    Fresno Community Science Workshop

    2011-01-01

    In this meteorology activity, learners build weather vanes using straws, paperclips, and cardstock. Learners will explore wind and air resistance as well as how weather vanes are used to understand and predict weather.

  6. Space Weathering of Lunar Rocks

    NASA Technical Reports Server (NTRS)

    Noble, S. K.; Keller, L. P.; Christoffersen, R.; Rahman, Z.

    2012-01-01

    All materials exposed at the lunar surface undergo space weathering processes. On the Moon, boulders make up only a small percentage of the exposed surface, and areas where such rocks are exposed, like central peaks, are often among the least space weathered regions identified from remote sensing data. Yet space weathered surfaces (patina) are relatively common on returned rock samples, some of which directly sample the surface of larger boulders. Because, as witness plates to lunar space weathering, rocks and boulders experience longer exposure times compared to lunar soil grains, they allow us to develop a deeper perspective on the relative importance of various weathering processes as a function of time.

  7. Future space-based sounding observations for weather analysis and forecasting

    Microsoft Academic Search

    W. L. Smith

    1992-01-01

    During this decade, advanced satellite remote sounding technology will be implemented as part of the Earth Observing System (EOS) program. Included are high spectral resolution, continuous spectral coverage, thermodynamic sounding infrared spectrometers which will provide greatly improved vertical resolution and accuracy. Advanced cloud penetrating microwave radiometers and very high spatial resolution imaging radiometers will accompany the infrared sounder to optimize

  8. SEM and TEM Observation of the Surfaces of the Fine-Grained Particles Retrieved from the Muses-C Regio on the Asteroid 25413 Itokawa

    NASA Technical Reports Server (NTRS)

    Noguchi, T.; Nakamura, T.; Zolensky, Michael E.; Tanaka, M.; Hashimoto, T.; Konno, M.; Nakato, A.; Ogami, T.; Fujimura, A.; Abe, M.; Yada, T.; Mukai, T.; Ueno, M.; Okada, T.; Shirai, K.; Ishibashi, Y.; Okazaki, R.

    2011-01-01

    Surface materials on airless solar system bodies exposed to interplanetary space are gradually changed their visible to near-infrared reflectance spectra by the process called "space weathering", which makes the spectra darker and redder. Hapke et al. proposed a model of space weathering: vapor deposition of nanophase reduced iron (npFe(sup 0)) on the surfaces of the grains within the very surface of lunar regolith. This model has been proved by detailed observation of the surfaces of the lunar soil grains by transmission electron microscope (TEM). They demonstrated that npFe(sup 0) was formed by a combination of vapor deposition and irradiation effects. In other words, both micrometeorite impacts and irradiation by solar wind and galactic cosmic ray play roles on the space weathering on the Moon. Because there is a continuum of reflectance spectra from those of Q-type asteroids (almost the same as those of ordinary chondrites) to those of S-type asteroids, it is strongly suggested that reflectance spectra of asteroids composed of ordinary chondrite-like materials were modified over time to those of S-type asteroids due to space weathering. It is predicted that a small amount of npFe(sup 0) on the surface of grains in the asteroidal regolith composed of ordinary chondrite-like materials is the main agent of asteroidal space weathering.

  9. Understanding midlatitude space weather: Storm impacts observed at Bear Lake Observatory on 31 March 2001

    Microsoft Academic Search

    J. J. Sojka; D. Rice; J. V. Eccles; F. T. Berkey; P. Kintner; W. Denig

    2004-01-01

    On 30 March 2001 in the late evening an auroral display was observed over the United States of America. The Bear Lake Observatory (BLO) magnetometer in Utah measured changes of 550 nT in less than 30 min. During the same period, BLO ionosonde measurements showed deep high-frequency radio wave absorption up to 7 MHz. BLO's GPS single-frequency receiver experienced geolocation

  10. The surface composition and temperature of asteroid 21 Lutetia as observed by Rosetta/VIRTIS.

    PubMed

    Coradini, A; Capaccioni, F; Erard, S; Arnold, G; De Sanctis, M C; Filacchione, G; Tosi, F; Barucci, M A; Capria, M T; Ammannito, E; Grassi, D; Piccioni, G; Giuppi, S; Bellucci, G; Benkhoff, J; Bibring, J P; Blanco, A; Blecka, M; Bockelee-Morvan, D; Carraro, F; Carlson, R; Carsenty, U; Cerroni, P; Colangeli, L; Combes, M; Combi, M; Crovisier, J; Drossart, P; Encrenaz, E T; Federico, C; Fink, U; Fonti, S; Giacomini, L; Ip, W H; Jaumann, R; Kuehrt, E; Langevin, Y; Magni, G; McCord, T; Mennella, V; Mottola, S; Neukum, G; Orofino, V; Palumbo, P; Schade, U; Schmitt, B; Taylor, F; Tiphene, D; Tozzi, G

    2011-10-28

    The Visible, InfraRed, and Thermal Imaging Spectrometer (VIRTIS) on Rosetta obtained hyperspectral images, spectral reflectance maps, and temperature maps of the asteroid 21 Lutetia. No absorption features, of either silicates or hydrated minerals, have been detected across the observed area in the spectral range from 0.4 to 3.5 micrometers. The surface temperature reaches a maximum value of 245 kelvin and correlates well with topographic features. The thermal inertia is in the range from 20 to 30 joules meter(-2) kelvin(-1) second(-0.5), comparable to a lunarlike powdery regolith. Spectral signatures of surface alteration, resulting from space weathering, seem to be missing. Lutetia is likely a remnant of the primordial planetesimal population, unaltered by differentiation processes and composed of chondritic materials of enstatitic or carbonaceous origin, dominated by iron-poor minerals that have not suffered aqueous alteration. PMID:22034430

  11. Coastal Observations of Weather Features in Senegal during the AMMA SOP-3 Period

    NASA Technical Reports Server (NTRS)

    Jenkins, G.; Kucera, P.; Joseph, E.; Fuentes, J.; Gaye, A.; Gerlach, J.; Roux, F.; Viltard, N.; Papazzoni, M.; Protat, A.; Bouniol, D.; Reynolds, A.; Arnault, J.; Badiane, D.; Kebe, F.; Camara, M.; Sall, S.

    2009-01-01

    During 15 August through 30 September 2006, ground and aircraft measurements were obtained from a multi-national group of students and scientists in Senegal. Key measurements were aimed at investigating and understanding precipitation processes, thermodynamic and dynamic environmental conditions, cloud, aerosol and microphysical processes and spaceborne sensors (TRMM, CloudSat/Calipso) validation. Ground and aircraft instruments include: ground based polarimetric radar, disdrometer measurements, a course and a high-density rain gauge network, surface chemical measurements, a 10 m flux tower, broadband IR, solar and microwave measurements, rawinsonde and radiosonde measurements, FA-20 dropsonde, in situ microphysics and cloud radar measurements. Highlights during SOP3 include ground and aircraft measurements of squall lines, African Easterly Waves (AEWs), Saharan Air Layer advances into Senegal, and aircraft measurements of AEWs -- including the perturbation that became Hurricane Isaac.

  12. A lagged response to the 11 year solar cycle in observed winter Atlantic/European weather patterns

    NASA Astrophysics Data System (ADS)

    Gray, Lesley J.; Scaife, Adam A.; Mitchell, Daniel M.; Osprey, Scott; Ineson, Sarah; Hardiman, Steven; Butchart, Neal; Knight, Jeff; Sutton, Rowan; Kodera, Kunihiko

    2013-12-01

    surface response to 11 year solar cycle variations is investigated by analyzing the long-term mean sea level pressure and sea surface temperature observations for the period 1870-2010. The analysis reveals a statistically significant 11 year solar signal over Europe, and the North Atlantic provided that the data are lagged by a few years. The delayed signal resembles the positive phase of the North Atlantic Oscillation (NAO) following a solar maximum. The corresponding sea surface temperature response is consistent with this. A similar analysis is performed on long-term climate simulations from a coupled ocean-atmosphere version of the Hadley Centre model that has an extended upper lid so that influences of solar variability via the stratosphere are well resolved. The model reproduces the positive NAO signal over the Atlantic/European sector, but the lag of the surface response is not well reproduced. Possible mechanisms for the lagged nature of the observed response are discussed.

  13. Site characterization summary report for dry weather surface water sampling upper East Fork Poplar Creek characterization area Oak Ridge Y-12 Plant, Oak Ridge, Tennessee

    SciTech Connect

    NONE

    1996-08-01

    This report describes activities associated with conducting dry weather surface water sampling of Upper East Fork Poplar Creek (UEFPC) at the Oak Ridge Y-12 Plant, Oak Ridge, Tennessee. This activity is a portion of the work to be performed at UEFPC Operable Unit (OU) 1 [now known as the UEFPC Characterization Area (CA)], as described in the RCRA Facility Investigation Plan for Group 4 at the Oak- Ridge Y-12 Plant, Oak Ridge, Tennessee and in the Response to Comments and Recommendations on RCRA Facility Investigation Plan for Group 4 at the Oak Ridge Y-12 Plant, Oak Ridge, Tennessee, Volume 1, Operable Unit 1. Because these documents contained sensitive information, they were labeled as unclassified controlled nuclear information and as such are not readily available for public review. To address this issue the U.S. Department of Energy (DOE) published an unclassified, nonsensitive version of the initial plan, text and appendixes, of this Resource Conservation and Recovery Act (RCRA) Facility Investigation (RFI) Plan in early 1994. These documents describe a program for collecting four rounds of wet weather and dry weather surface water samples and one round of sediment samples from UEFPC. They provide the strategy for the overall sample collection program including dry weather sampling, wet weather sampling, and sediment sampling. Figure 1.1 is a schematic flowchart of the overall sampling strategy and other associated activities. A Quality Assurance Project Plan (QAPJP) was prepared to specifically address four rounds of dry weather surface water sampling and one round of sediment sampling. For a variety of reasons, sediment sampling has not been conducted and has been deferred to the UEFPC CA Remedial Investigation (RI), as has wet weather sampling.

  14. Estimation of planetary surface roughness by HF sounder observation

    NASA Astrophysics Data System (ADS)

    Kobayashi, T.; Ono, T.

    Japanese Martian exploration project "Nozomi" was to carry out several science missions. Plasma Wave Sounder, one of those onboard missions, was an HF sounder to study Martian plasma environment, and Martian surface with the altimetry mode (Oya and Ono, 1998) as well. The altimetry mode observation was studied by means of computer simulations utilizing the KiSS code which had been originally designed to simulate the SELENE Lunar Radar Sounder, a spaceborne HF GPR, based on Kirchhoff approximation theory (Kobayashi, Oya and Ono, 2002). We found an empirical power law for the standard deviation of observed altitudes over Gaussian random rough surfaces: it varies in proportion to the square of the RMS gradient of the surface ?{2} hRMS{?_0, where hRMS and ?_0 are the RMS height of the surface and the correlation distance of the surface, respectively. We applied Geometrical optics to understand this empirical power law, and derived a square power law for the standard deviation of the observed altitude. Our Geometrical optics model assumed the followings: 1) the observed surface is a Gaussian random rough surface, 2) the mean surface is a flat horizontal plane, 3) the observed surface echo is the back scattering echoes, 4) the observed altitude is the mean value of the apparent range of those back scattering echoes. These results imply that HF sounder may be utilized to measure the surface roughness of planetary bodies in terms of the RMS gradient of the surface. Refrence: H. Oya and T. Ono, A new altimeter for Mars land shape observations utilizing the ionospheric sounder system onboard the Planet-B spacecraft, Earth Planets Space, Vol. 50, pp.229-234, 1998 T. Kobayashi, H. Oya, and T. Ono, A-scope analysis of subsurface radar sounding of lunar mare region, Earth Planets Space, Vol. 54, pp.973-982, 2002

  15. Using Forecasting to Teach Weather Science

    NASA Astrophysics Data System (ADS)

    Tsubota, Y.; Takahashi, T.

    2009-09-01

    Weather affects our lives and hence, is a popular topic in daily conversations and in the media. Therefore, it is not only important to teach weather, but is also a good idea to use 'weather' as a topic in science teaching. Science education has two main objectives: to acquire scientific concepts and methods. Weather forecasting is an adequate theme to teach scientific methods because it is dependent on observation. However, it is not easy to forecast weather using only temporal observation. We need to know the tendency of 'weather change' via consecutive and/or continuous weather observation. Students will acquire scientific-observation skills through weather observation. Data-processing skills would be enhanced through a weather-forecasting contest. A contest should be announced within 5 days of school events, such as a school excursion and field day. Students submit their own weather forecast by gathering weather information through the internet, news paper and so on. A weather-forecasting contest compels the student to observe the weather more often. We currently have some different weather forecasts. For example, American weather-related companies such as ACCU weather and Weather Channel provide weather forecast for the many locations all over the world. Comparing these weather forecasting with actual weather, participants such as students could evaluate the differences between forecasted and actual temperatures. Participants will judge the best weather forecast based on the magnitude of the difference. Also, participants evaluate the 'hitting ratio' of each weather forecast. Students can learn elementary statistics by comparing various weather forecasts. We have developed our weather web-site that provides our own weather forecasting and observation. Students acquire science skills using our weather web-site. We will report our lessen plans and explain our weather web-site.

  16. Studying the Space Weather Features of the High-Latitude Ionosphere by Using a Physics-Based Data Assimilation Model and Observational Data from Ground Magnetometer Arrays

    NASA Astrophysics Data System (ADS)

    Zhu, L.; Schunk, R. W.; Scherliess, L.; Sojka, J. J.; Eccles, J. V.

    2011-12-01

    The high-latitude ionosphere is a very dynamic region in the solar-terrestrial environment. Frequent disturbances in the region can adversely affect numerous military and civilian technologies. Accurate specifications and forecasts of the high-latitude electrodynamic and plasma structures have fundamental space weather importance for enabling mitigation of adverse effects. Presently, most of the space-weather models use limited observations and/or indices to define a set of empirical drivers for physical models to move forward in time. Since the empirical drivers have a "climatological" nature and there are significant physical inconsistencies among various empirical drivers due to independent statistical analysis of different observational data, the specifications of high-latitude space environment from these space weather models cannot truthfully reflect the weather features. In fact, unrealistic small- and large-scale structures could be produced in the specifications and forecasts from these models. We developed a data assimilation model for the high-latitude ionospheric plasma dynamics and electrodynamics to overcome these hurdles. With a set of physical models and an ensemble Kalman filter, the data assimilation model can determine the self-consistent structures of the high-latitude convection electric field, ionospheric conductivity, and the key drivers associated with these quantities by ingesting data from multiple observations. These ingested data include the magnetic perturbation from the ground-based magnetometers in the high-latitude regions, magnetic measurements of IRIDIUM satellites, SuperDARN line-of-sight velocity, and in-situ drift velocity measured by DMSP satellites. As a result, the assimilation model can capture the small- and large-scale plasma structures and sharp electrodynamic boundaries, thus, can provide a more accurate picture of the high-latitude space weather. In this presentation, we will first briefly describe the data-assimilation model of high-latitude electrodynamics and its strengths over the other space-weather models. Then we will present the space weather features produced by the model for quiet and storm periods constrained by the data from ground magnetometer arrays. This will demonstrate the dynamic variability of the high-latitude ionosphere. Finally, we will present high-resolution ionospheric modeling results of the time-evolution and spatial features of the high-latitude plasma structures to further demonstrate the model's capability in producing the space weather features in the high-latitude ionosphere. These results will illuminate the importance of real-time data availability and data assimilation models for accurate specification and forecasting of space weather.

  17. Eliminating error in satellite observations of surface elevation

    NASA Astrophysics Data System (ADS)

    Schultz, Colin

    2014-01-01

    From 2003 to 2009, NASA's Ice, Cloud, and Land Elevation Satellite (ICESat) captured detailed elevation measurements of the Earth's surface. Unfortunately, as with all instruments, ICESat's observations experienced sensor drift throughout its lifetime, a changing bias that introduced error into the satellite's observations. Correcting for such creeping biases is difficult but crucial for maximizing the value of the observational record.

  18. A Dozen Years of Temperature Observations at the Summit: Central Greenland Automatic Weather Stations 1987-99.

    NASA Astrophysics Data System (ADS)

    Shuman, Christopher A.; Steffen, Konrad; Box, Jason E.; Stearns, Charles R.

    2001-04-01

    On 4 May 1987, the first automatic weather station (AWS) near the summit of the Greenland Ice Sheet began transmitting data. Air temperature records from this site, AWS Cathy, as well as nearby AWS at the Greenland Ice Sheet Project II (GISP2, now Summit) camp have been combined with Special Sensor Microwave Imager brightness temperature data to create a composite temperature history of the Greenland summit. This decadal-plus-length (4536 days) record covers the period from May 1987 to October 1999 and continues currently. The record is derived primarily from near-surface temperature data from AWS Cathy (May 1987-May 1989), AWS GISP2 (June 1989-November 1996), and AWS Summit (May 1996 and continuing). Despite the 35-km distance between them, the AWS Cathy data have been converted to the equivalent basis of temperatures from the AWS GISP2 and AWS Summit locations. The now completed `Summit' temperature time series represents a unique record that documents a multiyear temperature recovery after the eruption of Mt. Pinatubo in June 1991 and that initiates a baseline needed for climate change detection.

  19. Climatological characteristics of fronts in the western North Pacific based on surface weather charts

    NASA Astrophysics Data System (ADS)

    Utsumi, Nobuyuki; Kim, Hyungjun; Seto, Shinta; Kanae, Shinjiro; Oki, Taikan

    2014-08-01

    Composite front climatology in the western North Pacific is determined using a newly developed 1.0° gridded data set. Here we propose a research strategy for determining the spatiotemporal distribution of fronts using weather chart images published by the Japan Meteorological Agency, one of the major data providers in the region. A preliminarily investigation of the internal data characteristics for the period of 2000-2010 is undertaken, and the final 4 years of data are used for an analysis of front climatology to avoid the effect of any spurious trends. This enables in-depth analyses to be conducted, which have not previously been possible in the region, including the composites of cross-sectional patterns for the thermal fields and precipitation near fronts, front length seasonality, and the significance of the thermal gradient near the fronts, in addition to determining the frontal frequency and spatial distribution of frontal precipitation. Pixel-wise analysis reveals that 56% of the local precipitation maximum is located on the warm side of a cold front caused by less tilted upward motion on the warm side, with the intrusion of the upper level cold dry air into the warm side. This new data set also enables a further analysis of the occluded fronts, which are not correctly distinguished in the existing objective detection method.

  20. Spectroscopic analyses of Fe and water in clays: A Martian surface weathering study

    NASA Technical Reports Server (NTRS)

    Bishop, J. L.; Pieters, Carle M.; Edwards, J. O.; Coyne, L. M.; Chang, S.

    1991-01-01

    Martian surface morphology suggests the presence of liquid H2O on Mars in the past. Reflectance spectra of the Martian surface include features which correspond to the crystal field transitions of iron, as well as features supporting the presence of ice and minerals containing structural OH and surface water. Researchers initiated further spectroscopic studies of surface iron and water and structural OH in clays in order to determine what remotely obtained spectra can indicate about the presence of clays on Mars based on a clearer understanding of the factors influencing the spectral features. Current technology allows researchers to better correlate the low frequency fundamental stretching and bending vibrations of O-H bonds with the diagnostic near infrared overtone and combination bands used in mineral characterization and identification.

  1. UM Weather

    NSDL National Science Digital Library

    Sponsored by The Weather Underground at the University of Michigan at Ann Arbor, UM Weather bills itself as the "Internet's premier source of weather information." The site offers several general audience tools such as the Fast Forecast for any city in the US, ski weather, and weather cams. But, it also provides access to over two dozen weather software packages, a new computer model forecasts page, and most impressively a list of close to 400 other weather related Web sites. Professionals and researchers will appreciate the non-technical feel of the site and the valuable information they can procure from it.

  2. Severe Weather

    NSDL National Science Digital Library

    National Science Teachers Association (NSTA)

    2005-04-01

    Meteorologists disagree as to what constitutes severe weather. However, most concur that thunderstorms, tornadoes, and hurricanes, all considered to be "convective" weather, fit the definition of severe weather, which is a weather condition likely to cause hardship. This science guide will explore each of the three weather phenomena. By virtue of their locations, most students are familiar with at least one of the three severe weather events. Students who tour the web sites will have an opportunity to make connections between the familiar and the perhaps less understood weather events.

  3. BBC Weather

    NSDL National Science Digital Library

    At this website, the BBC offers an array of materials dealing with weather. Meteorologists can discover employment opportunities. Individuals with spectacular photographs of weather phenomenon can submit their images to the photo gallery. Students and educators can find introductory materials on basic weather concepts, forecasting, extreme events, and broadcasting the weather. The website offers fun weather-related games and projects, a meteorology glossary, and links to other educational websites.

  4. Weather and climate

    NASA Technical Reports Server (NTRS)

    1975-01-01

    Recommendations for using space observations of weather and climate to aid in solving earth based problems are given. Special attention was given to: (1) extending useful forecasting capability of space systems, (2) reducing social, economic, and human losses caused by weather, (3) development of space system capability to manage and control air pollutant concentrations, and (4) establish mechanisms for the national examination of deliberate and inadvertent means for modifying weather and climate.

  5. Weather automation studies at the Otis Weather Test Facility

    Microsoft Academic Search

    D. A. Chisholm

    1978-01-01

    A description of the Otis Weather Test Facility (WTF) is presented, taking into account the distribution of surface-based and tower-mounted instrumentation at the WTF, the automation of the rotating beam ceilometer, the present weather decision tree, and slant visual range techniques. A demonstration model of a Modular Automated Weather System (MAWS) is also considered. The versatility of MAWS results from

  6. Aeolian weathering of Venusian surface materials - preliminary results from laboratory simulations

    SciTech Connect

    Marshall, J.R.; Greeley, R.; Tucker, D.W.; Pollack, J.B.

    1988-06-01

    An attempt is made to duplicate the atmospheric temperature, pressure, and approximate gas composition of all surface elevations on Venus by means of a simulator environment in which particles are impacted against rock targets as a way of studying planetary aeolian processes. While particles are abraded even at the low impact velocities envisioned for Venus, the same particles do not generate basaltic rock abrasion for impact velocities lower than 1 m/sec; comminution debris is instead transferred onto rock surfaces to form an accretion layer. These phenomena are seen as functions of the greater than 660 K temperatures encountered. 44 references.

  7. Mountain Weather

    NSDL National Science Digital Library

    Mountains can be awe-inspiring both for the vistas they provide and for the weather events and long-term climate systems they support. This interactive feature illustrates how a moisture-laden air mass interacts with a mountain slope to produce characteristic patterns of precipitation over the mountain and surrounding areas. Viewers can see how clouds and precipitation form as the air mass ascends the windward side of the peak, and observe the rain shadow created on the leeward side by the descending, warmed, and moisture-depleted air. A background essay and list of discussion questions supplement the interactive feature.

  8. Weather Photography

    NSDL National Science Digital Library

    Ph.D. student Harald Edens describes himself as a "photographer of lightning, clouds, atmospheric optical phenomena and astronomy". His Web site entitled Weather Photography proves this by providing a stunning collection of photographs and movies of atmospheric optics, lightning, clouds, and astronomy. The author describes how the photographs were taken, what equipment was used, and even discusses many of the phenomenon being observed such as mirages and halos. An added bonus of this very interesting site is that the author generously allows free personal use of the photographs.

  9. The widely used Weather Research and Forecasting (WRF) model provides a few land surface schemes

    E-print Network

    Menut, Laurent

    - responding heat capacities and densities. Vegetation impact on evaporation is taken into account with can of meteorological parameters, as well as vertical profiles measured by a lidar. The simulation results are compared: from the soil surface, from wet canopies, and as evapotranspiration from vegetation. These components

  10. Developing a TeraGrid Based Land Surface Hydrology and Weather Modeling Interface

    E-print Network

    Jiang, Wen

    of Cyberinfrastructure for End-to-End Environmental Explorations (C4E4), this multi-disciplinary team utilizes current, fusion of data and models has been undertaken by the C4E4 team over the St. Joseph watershed in Northern/hydrological modeling interface using a Surface Water Analysis Tool (SWAT). The focus of the current paper is to discuss

  11. Constructing design weather data for future climates

    Microsoft Academic Search

    SE Belcher; JN Hacker; DS Powell

    2005-01-01

    We develop a method, here called ‘morphing’, to produce design weather data for building thermal simulations that accounts for future changes to climate. Morphing combines present-day observed weather data with results from climate models. The procedure yields weather time series that encapsulate the average weather conditions of future climate scenarios, whilst preserving realistic weather sequences. In this sense the method

  12. Observed decadal variations in surface solar radiation and their causes

    Microsoft Academic Search

    Atsumu Ohmura

    2009-01-01

    Long-term variations of global solar irradiance at the Earth's surface from the beginning of the observations to 2005 are analyzed for more than 400 sites. Further, likely causes for the variations, an estimation of the magnitudes of aerosol direct and indirect effects, and the temperature sensitivity of the climate system due to radiation changes are evaluated. The record of observed

  13. Estimating long-term surface hydrological components by coupling remote sensing observation with surface flux model.

    SciTech Connect

    Song, J.; Wesely, M. L.

    2002-05-02

    A model framework for parameterized subgrid-scale surface fluxes (PASS) has been applied to use satellite data, models, and routine surface observations to infer root-zone available moisture content and evapotranspiration rate with moderate spatial resolution within Walnut River Watershed in Kansas. Biweekly composite normalized difference vegetative index (NDVI) data are derived from observations by National Oceanic and Atmospheric Administration (NOAA) satellites. Local surface observations provide data on downwelling solar irradiance, air temperature, relative humidity, and wind speed. Surface parameters including roughness length, albedo, surface water conductance, and the ratio of soil heat flux to net radiation are estimated; pixel-specific near-surface meteorological conditions such as air temperature, vapor pressure, and wind speed are adjusted according to local surface forcing. The PASS modeling system makes effective use of satellite data and can be run for large areas for which flux data do not exist and surface meteorological data are available from only a limited number of ground stations. The long-term surface hydrological budget is evaluated using radar-derived precipitation estimates, surface meteorological observations, and satellite data. The modeled hydrological components in the Walnut River Watershed compare well with stream gauge data and observed surface fluxes during 1999.

  14. Observations During GRIP from HIRAD: Ocean Surface Wind Speed and Rain Rate

    NASA Technical Reports Server (NTRS)

    Miller, Timothy L.; James, M. W.; Jones, L.; Ruf, C. S.; Uhlhorn, E. W.; Bailey, M. C.; Buckley, C. D.; Simmons, D. E.; Johnstone, S.; Peterson, A.; Schultz, L. A.; Biewas, S.; Johnson, J. W.; Shah, G.; Feingstein, D.; Cleveland, W. H.; Johnson, J.; Hood, R. E.

    2011-01-01

    HIRAD (Hurricane Imaging Radiometer) flew on the WB-57 during NASA's GRIP (Genesis and Rapid Intensification Processes) campaign in August - September of 2010. HIRAD is a new C-band radiometer using a synthetic thinned array radiometer (STAR) technology to obtain cross-track resolution of approximately 3 degrees, out to approximately 60 degrees to each side of nadir. By obtaining measurements of emissions at 4, 5, 6, and 6.6 GHz, observations of ocean surface wind speed and rain rate can be inferred. This technique has been used for many years by precursor instruments, including the Stepped Frequency Microwave Radiometer (SFMR), which has been flying on the NOAA and USAF hurricane reconnaissance aircraft for several years. The advantage of HIRAD over SFMR is that HIRAD can observe a +/- 60-degree swath, rather than a single footprint at nadir angle. Results from the flights during the GRIP campaign will be shown, including images of brightness temperatures, wind speed, and rain rate. To the extent possible, comparisons will be made with observations from other instruments on the GRIP campaign, for which HIRAD observations are either directly comparable or are complementary. Potential impacts on operational ocean surface wind analyses and on numerical weather forecasts will also be discussed.

  15. RECONSTRUCTING CORONAL MASS EJECTIONS WITH COORDINATED IMAGING AND IN SITU OBSERVATIONS: GLOBAL STRUCTURE, KINEMATICS, AND IMPLICATIONS FOR SPACE WEATHER FORECASTING

    SciTech Connect

    Liu Ying; Luhmann, Janet G.; Lin, Robert P.; Bale, Stuart D. [Space Sciences Laboratory, University of California, Berkeley, CA 94720 (United States); Thernisien, Arnaud [Universities of Space Research Association, Columbia, MD 21044 (United States); Vourlidas, Angelos [Space Science Division, Naval Research Laboratory, Washington, DC 20375 (United States); Davies, Jackie A., E-mail: liuxying@ssl.berkeley.ed [Space Science and Technology Department, Rutherford Appleton Laboratory, Didcot (United Kingdom)

    2010-10-20

    We reconstruct the global structure and kinematics of coronal mass ejections (CMEs) using coordinated imaging and in situ observations from multiple vantage points. A forward modeling technique, which assumes a rope-like morphology for CMEs, is used to determine the global structure (including orientation and propagation direction) from coronagraph observations. We reconstruct the corresponding structure from in situ measurements at 1 AU with the Grad-Shafranov method, which gives the flux-rope orientation, cross section, and a rough knowledge of the propagation direction. CME kinematics (propagation direction and radial distance) during the transit from the Sun to 1 AU are studied with a geometric triangulation technique, which provides an unambiguous association between solar observations and in situ signatures; a track fitting approach is invoked when data are available from only one spacecraft. We show how the results obtained from imaging and in situ data can be compared by applying these methods to the 2007 November 14-16 and 2008 December 12 CMEs. This merged imaging and in situ study shows important consequences and implications for CME research as well as space weather forecasting: (1) CME propagation directions can be determined to a relatively good precision as shown by the consistency between different methods; (2) the geometric triangulation technique shows a promising capability to link solar observations with corresponding in situ signatures at 1 AU and to predict CME arrival at the Earth; (3) the flux rope within CMEs, which has the most hazardous southward magnetic field, cannot be imaged at large distances due to expansion; (4) the flux-rope orientation derived from in situ measurements at 1 AU may have a large deviation from that determined by coronagraph image modeling; and (5) we find, for the first time, that CMEs undergo a westward migration with respect to the Sun-Earth line at their acceleration phase, which we suggest is a universal feature produced by the magnetic field connecting the Sun and ejecta. The importance of having dedicated spacecraft at L4 and L5, which are well situated for the triangulation concept, is also discussed based on the results.

  16. Surface Turbulent Fluxes Over Pack Ice Inferred from TOVS Observations

    NASA Technical Reports Server (NTRS)

    Lindsay, R. W.; Francis, J. A.; Persson, P. O. G.; Rothrock, D. A.; Schweiger, A. J.

    1996-01-01

    A one-dimensional, atmospheric boundary layer model is coupled to a thermodynamic ice model to estimate the surface turbulent fluxes over thick sea ice. The principal forcing parameters in this time-dependent model are the air temperature, humidity, and wind speed at a specified level (either at 2 m or at 850 mb) and the downwelling surface radiative fluxes. The free parameters. are the air temperature, humidity, and wind speed profiles below the specified level, the surface skin temperature, the ice temperature profile, and the surface turbulent fluxes. The goal is to determine how well we can estimate the turbulent surface heat and momentum fluxes using forcing parameters from atmospheric temperatures and radiative fluxes retrieved from the TIROS-N Operational Vertical Sounder (TOVS) data. Meteorological observations from the Lead Experiment (LeadEx, April 1992) ice camp are used to validate turbulent fluxes computed with the surface observations and the results are used to compare with estimates based on radio-sonde observations or with estimates based on TOVS data. We find that the TOVS-based estimates of the stress are significantly more accurate than those found with a constant geostrophic drag coefficient, with a root-mean-square error about half as large. This improvement is due to stratification effects included in the boundary layer model. The errors in the sensible heat flux estimates, however, are large compared to the small mean values observed during the field experiment.

  17. Thermal infrared spectroscopic observations of Mars from the Kuiper Airborne Observatory (KAO): Constraints on past climates and weathering products

    NASA Technical Reports Server (NTRS)

    Roush, Ted L.; Pollack, James B.; Witteborn, Fred C.; Bregman, Jesse D.; Bell, James F., III; Sitton, Bradley

    1995-01-01

    Spectral observations providing evidence for the presence of volatile-bearing minerals on the surface of Mars were obtained in 1988 and 1990 from the KAO. The 1988 data suggest the presence of 1-3 weight percent (wt%) of carbonate/bicarbonate and 10-15 wt% sulfate/bisulfate associated with martian atmospheric dust. Estimates of the optical depths are approximately 0.60 and approximately 0.35 in 1988 and 1990, respectively.

  18. An observational correlation between stellar brightness variations and surface gravity.

    PubMed

    Bastien, Fabienne A; Stassun, Keivan G; Basri, Gibor; Pepper, Joshua

    2013-08-22

    Surface gravity is a basic stellar property, but it is difficult to measure accurately, with typical uncertainties of 25 to 50 per cent if measured spectroscopically and 90 to 150 per cent if measured photometrically. Asteroseismology measures gravity with an uncertainty of about 2 per cent but is restricted to relatively small samples of bright stars, most of which are giants. The availability of high-precision measurements of brightness variations for more than 150,000 stars provides an opportunity to investigate whether the variations can be used to determine surface gravities. The Fourier power of granulation on a star's surface correlates physically with surface gravity: if brightness variations on timescales of hours arise from granulation, then such variations should correlate with surface gravity. Here we report an analysis of archival data that reveals an observational correlation between surface gravity and root mean squared brightness variations on timescales of less than eight hours for stars with temperatures of 4,500 to 6,750?kelvin, log surface gravities of 2.5 to 4.5 (cgs units) and overall brightness variations of less than three parts per thousand. A straightforward observation of optical brightness variations therefore allows a determination of the surface gravity with a precision of better than 25 per cent for inactive Sun-like stars at main-sequence to giant stages of evolution. PMID:23969460

  19. Naturally weathered feldspar surfaces in the Navajo Sandstone aquifer, Black Mesa, Arizona: Electron microscopic characterization

    E-print Network

    Zhu, Chen

    emission gun scanning electron microscope (FEG- SEM). Here, we report the first HRTEM observation of a 10: Electron microscopic characterization Chen Zhu a,*, David R. Veblen b , Alex E. Blum c , Stephen J. Chipera, was characterized with high-reso- lution transmission and analytical electron microscope (HRTEM-AEM) and field

  20. Weather Report

    NSDL National Science Digital Library

    This printable weather report is designed to help students easily note a field site's important meteorological details. The one-page PDF form asks for the following information: date, temperature, precipitation, weather type, and wind speed (based on environmental clues).

  1. Winter Weather

    MedlinePLUS

    ... About CDC.gov . Natural Disasters and Severe Weather Earthquakes Being Prepared Emergency Supplies Home Hazards Indoor Safety ... What's New A - Z Index Disasters & Severe Weather Earthquakes Extreme Heat Floods Hurricanes Landslides Tornadoes Tsunamis Volcanoes ...

  2. Toward the Assimilation of the Atmospheric Surface Layer Using Numerical Weather Prediction and Radar Clutter Observations

    E-print Network

    Gerstoft, Peter

    , California PETER GERSTOFT AND WILLIAM S. HODGKISS Scripps Institution of Oceanography, University and rocketsondes are in situ methods for sampling the ASL (Rowland et al. 1996). While having some limitations

  3. Weather Talk

    NSDL National Science Digital Library

    Weather Talk is a primer on weather and naval meteorology. It provides a brief overview of major weather elements and is presented in a non-mathematical way, so that the reader will have a better understanding of the basic mechanisms of weather and use it to their advantage and safety in planning and carrying out their own activities. The site explains temperature, wind, pressure, atmospheric moisture, air masses and fronts, thunderstorms, tornadoes, hurricanes, and climatology.

  4. Satellite-based albedo, sea surface temperature and effective land roughness maps used in the HIRLAM model for weather and climate scenarios

    Microsoft Academic Search

    C. B. Hasager; N. W. Nielsen; J. H. Christensen; H. Soegaard; E. Boegh; M. S. Rasmussen; N. O. Jensen

    2001-01-01

    A study is conducted on the effect of introducing maps of geophysical parameters retrieved from satellite Earth Observation data into the atmospheric model HIRLAM (HIgh Resolution Limited Area Model). . The HIRLAM system was developed by the HIRLAM project group, a cooperative project of the national weather services in Denmark, Finland, Iceland, Ireland, the Netherlands, Norway and Sweden. It is

  5. Destabilization of olivine by 30-keV electron irradiation: a possible mechanism of space weathering affecting interplanetary dust particles and planetary surfaces

    NASA Astrophysics Data System (ADS)

    Lemelle, L.; Beaunier, L.; Borensztajn, S.; Fialin, M.; Guyot, F.

    2003-05-01

    Electron irradiation experiments were performed using a 30-keV electron beam on single crystals of olivine in a scanning electron microscope (SEM) and in an electron microprobe (EMP). We determined that, under certain conditions, structural damage is caused to the irradiated surface of iron-bearing olivines. The irradiated areas comprise spherules with sizes of hundreds of nanometers and micrometer-sized holes. In the immediate vicinities of the irradiated areas, droplets with sizes of tens of nanometers and branching tracks are observed. With increasing total charge, the hundreds of nanometer-sized spherules become larger and more irregular in shape. The size and shape of the nanometer-sized droplets remain almost constant, but their surface density increases (in m -2). Chemical fractionations compared to the initial olivine were found: the irradiated areas are slightly enriched in MgO, whereas the deposits are enriched in SiO 2. Destabilization of olivine is not due to the dissipation of the implanted energy as heat, but results most probably from electrostatic discharges leading to the breakdown of the dielectric lattice. The possibility that such processes could be responsible for significant space weathering of interplanetary dust particles and regoliths of planetary surfaces should be taken into account. In the interplanetary medium, 10-keV range electrons are carried by the solar wind, whereas at 1 AU from the Sun, the lifetime of cometary dust and the exposure time of lunar regolith are, at least, 10 to 100 times greater than the duration required to accumulate the damaging electronic doses applied in this study. Moreover, the comparison of the microstructures of samples irradiated in the present study with features of lunar regolith grains reveals several chemical and structural similarities.

  6. Space Weather Simulators Developed at NICT : the Solar Surface-Solar Wind Coupling Model and the Next Generation Magnetosphere-Ionosphere Coupling Model

    NASA Astrophysics Data System (ADS)

    Den, Mitsue; Nagatsuma, Tsutomu; Watari, Shinichi; Tanaka, Takashi; Ishii, Mamoru; Kubo, Yuki; Kubota, Yasubumi; Washimi, Haruichi

    We report two global MHD simulators developed at NICT (National Institute of Information and Communications Technology): one is for the solar surface-solar wind coupling system and the other is for the magnetosphere-ionosphere coupling system. One important feature of our simulation model is the 3-D grid system, which has no polar singularity despite of a spherical grid configuration. By this grid system, fine grids can be allocated near the inner boundary which represents the sun or the earth. Some complicated magnetic structures on the solar surface is closely related with the solar disturbances, and in the same way the ionospheric aurora is closely related with the the magnetospheric reconfiguration processes. In views of these situation, it is very crucial for both models to achieve the simultaneous implementations for the fine grid structure on the inner boundary and the wide range grids in global configuration. For the solar surface-solar wind coupling system, the observed magnetic field data are input at the inner boundary, and the solar wind structure can be updated at every day by optimizing the simulation code. For the magnetospheric model, we are developing "the next generation" realtime MHD simulation system. The model is developed by NICT and co-workers, and the extreme phenomena such as the magnetopause crossing are simulated successfully. For the magnetic disturbance event, the westward traveling surge, the most characteristic feature of the substorm, is reproduced quite realistically. In this paper, we describe those two space weather simulator systems and represent several numerical results obtained by using these models.

  7. Emergent relation between surface vapor conductance and relative humidity profiles yields evaporation rates from weather data.

    PubMed

    Salvucci, Guido D; Gentine, Pierre

    2013-04-16

    The ability to predict terrestrial evapotranspiration (E) is limited by the complexity of rate-limiting pathways as water moves through the soil, vegetation (roots, xylem, stomata), canopy air space, and the atmospheric boundary layer. The impossibility of specifying the numerous parameters required to model this process in full spatial detail has necessitated spatially upscaled models that depend on effective parameters such as the surface vapor conductance (C(surf)). C(surf) accounts for the biophysical and hydrological effects on diffusion through the soil and vegetation substrate. This approach, however, requires either site-specific calibration of C(surf) to measured E, or further parameterization based on metrics such as leaf area, senescence state, stomatal conductance, soil texture, soil moisture, and water table depth. Here, we show that this key, rate-limiting, parameter can be estimated from an emergent relationship between the diurnal cycle of the relative humidity profile and E. The relation is that the vertical variance of the relative humidity profile is less than would occur for increased or decreased evaporation rates, suggesting that land-atmosphere feedback processes minimize this variance. It is found to hold over a wide range of climate conditions (arid-humid) and limiting factors (soil moisture, leaf area, energy). With this relation, estimates of E and C(surf) can be obtained globally from widely available meteorological measurements, many of which have been archived since the early 1900s. In conjunction with precipitation and stream flow, long-term E estimates provide insights and empirical constraints on projected accelerations of the hydrologic cycle. PMID:23576717

  8. A simplified bi-dimensional variational analysis of soil moisture from screen-level observations in a mesoscale numerical weather-prediction model

    Microsoft Academic Search

    G. Balsamo; F. Bouyssel; J. Noilhan

    2004-01-01

    The analysis of soil moisture for the initialization of a mesoscale numerical weather-prediction (NWP) model is considered subject to operational constraints, both in terms of computational cost and data availability. A variational technique is used to analyse the soil moisture by assimilating screen-level observations of temperature and relative humidity. We consider a simplified bi-dimensional (z and t) variational approach (simplified

  9. World Weather

    NSDL National Science Digital Library

    Elias, Jaume Sanchez

    2014-02-20

    What's going on in the world of weather? Are there storms around Sri Lanka? What about the snows of Kilimanjaro? These can be pressing questions, indeed, and the World Weather app is a great way to stay in touch with weather patterns around the globe. Users will find that they can just type in a city name to see the current weather and also zoom around the globe as they see fit. It's a remarkable addition to the world of existing weather tracking apps and is compatible with all operating systems.

  10. Weather Watcher

    NSDL National Science Digital Library

    Singer, Mike

    As spring progresses, weather conditions can continue to fluctuate dramatically, something that may foil vacation plans or other outings. Keeping that in mind, visitors may do well to download the Weather Watcher application created by Mike Singer. With this application, users may automatically retrieve the current weather conditions, look through hourly forecasts, keep abreast of severe weather alerts, and take a look at weather maps for almost any city world-wide. This application is compatible with all systems running Windows 98 and above.

  11. Differentiating the roles of photooxidation and biodegradation in the weathering of Light Louisiana Sweet crude oil in surface water from the Deepwater Horizon site.

    PubMed

    Bacosa, Hernando P; Erdner, Deana L; Liu, Zhanfei

    2015-06-15

    We determined the contributions of photooxidation and biodegradation to the weathering of Light Louisiana Sweet crude oil by incubating surface water from the Deepwater Horizon site under natural sunlight and temperature conditions. N-alkane biodegradation rate constants were ca. ten-fold higher than the photooxidation rate constants. For the 2-3 ring and 4-5 ring polycyclic aromatic hydrocarbons (PAHs), photooxidation rate constants were 0.08-0.98day(-1) and 0.01-0.07day(-1), respectively. The dispersant Corexit enhanced degradation of n-alkanes but not of PAHs. Compared to biodegradation, photooxidation increased transformation of 4-5 ring PAHs by 70% and 3-4 ring alkylated PAHs by 36%. For the first time we observed that sunlight inhibited biodegradation of pristane and phytane, possibly due to inhibition of the bacteria that can degrade branched-alkanes. This study provides quantitative measures of oil degradation under relevant field conditions crucial for understanding and modeling the fate of spilled oil in the northern Gulf of Mexico. PMID:25899525

  12. Using Forecast and Observed Weather Data to Assess Performance of Forecast Products in Identifying Heat Waves and Estimating Heat Wave Effects on Mortality

    PubMed Central

    Chen, Yeh-Hsin; Schwartz, Joel D.; Rood, Richard B.; O’Neill, Marie S.

    2014-01-01

    Background: Heat wave and health warning systems are activated based on forecasts of health-threatening hot weather. Objective: We estimated heat–mortality associations based on forecast and observed weather data in Detroit, Michigan, and compared the accuracy of forecast products for predicting heat waves. Methods: We derived and compared apparent temperature (AT) and heat wave days (with heat waves defined as ? 2 days of daily mean AT ? 95th percentile of warm-season average) from weather observations and six different forecast products. We used Poisson regression with and without adjustment for ozone and/or PM10 (particulate matter with aerodynamic diameter ? 10 ?m) to estimate and compare associations of daily all-cause mortality with observed and predicted AT and heat wave days. Results: The 1-day-ahead forecast of a local operational product, Revised Digital Forecast, had about half the number of false positives compared with all other forecasts. On average, controlling for heat waves, days with observed AT = 25.3°C were associated with 3.5% higher mortality (95% CI: –1.6, 8.8%) than days with AT = 8.5°C. Observed heat wave days were associated with 6.2% higher mortality (95% CI: –0.4, 13.2%) than non–heat wave days. The accuracy of predictions varied, but associations between mortality and forecast heat generally tended to overestimate heat effects, whereas associations with forecast heat waves tended to underestimate heat wave effects, relative to associations based on observed weather metrics. Conclusions: Our findings suggest that incorporating knowledge of local conditions may improve the accuracy of predictions used to activate heat wave and health warning systems. Citation: Zhang K, Chen YH, Schwartz JD, Rood RB, O’Neill MS. 2014. Using forecast and observed weather data to assess performance of forecast products in identifying heat waves and estimating heat wave effects on mortality. Environ Health Perspect 122:912–918;?http://dx.doi.org/10.1289/ehp.1306858 PMID:24833618

  13. Space weather effects on midlatitude HF propagation paths: Observations and a data-driven D region model

    Microsoft Academic Search

    J. V. Eccles; R. D. Hunsucker; D. Rice; J. J. Sojka

    2005-01-01

    A two-pronged study is under way to improve understanding of the D region response to space weather and its effects on HF propagation. One part, the HF Investigation of D region Ionospheric Variation Experiment (HIDIVE), is designed to obtain simultaneous, quantitative propagation and absorption data from an HF signal monitoring network along with solar X-ray flux from the NOAA GOES

  14. Surface heat budget at the Nordic Seas in Lagrangian observations

    NASA Astrophysics Data System (ADS)

    de La Lama, Marta S.; Isachsen, Pål E.; Koszalka, Inga; Lacasce, Joseph H.

    2014-05-01

    In the Nordic Seas, the warm, inflowing Atlantic Water is cooled until it is dense enough to sink. Thereafter it circulates at depth, eventually feeding the North Atlantic Deep Water. The air-sea interaction which facilitates this cooling is a complex process involving diverse phenomena, from surface heating to turbulent entrainment at the base of the ocean surface mixed layer. In the present study, we use 486 freely-drifting surface buoys to observe temperature changes on water parcels and the response to air-sea heat fluxes. Such Lagrangian observations advantageously 'filter out' horizontal heat fluxes, since the buoys are advected by the flow, allowing one to focus on the vertical exchanges. We examine the temporal evolution of temperature on the drifters and the correlations with surface heat fluxes, obtained from ECMWF ERA-Interim reanalyses. The frequency spectra indicate a clear ?-2 dependence at frequencies higher than roughly 1/40 days-1. The temperature fluctuations on the other hand are correlated with surface fluxes only at the longer time scales. We then show how the Lagrangian temperature can be represented as a stochastic process, with a deterministic portion determined by the low frequency atmospheric forcing and a white noise perturbation. This is in line with previous studies of the ocean surface response to stochastic wind forcing. What distinguishes the present model is the deterministic part, which must account for the gradual cooling of the water parcels.

  15. Titan's Surface Temperatures Maps from Cassini - CIRS Observations

    Microsoft Academic Search

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

    2009-01-01

    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 mum (530 cm-1) characterized by low opacity. Since the first acquisitions of CIRS Titan data the instrument has gathered

  16. Vertical transport of surface fire emissions observed from space

    Microsoft Academic Search

    Siegfried Gonzi; Paul I. Palmer

    2010-01-01

    We use optimal estimation to infer the vertical distribution of surface emissions lofted from boreal and tropical biomass burning during June–October (JJASO) 2006. We use satellite observations of CO, a tracer of incomplete combustion, at thermal infrared and microwave wavelengths from Aura Tropospheric Emission Spectrometer (TES) and Microwave Limb Sounder (MLS), respectively. TES and MLS together typically provide two to

  17. SOLAR AND METEOROLOGICAL SURFACE OBSERVATION NETWORK (SAMSON) FOR NC, VA

    EPA Science Inventory

    Solar and Meteorological Surface Observational Network (SAMSON) v1.0 data for 6 NWS stations in North Carolina and 4 in Virginia. Hourly solar elements are: extraterrestrial horizontal and extraterrestrial direct normal radiation; global, diffuse, and direct normal radiation. Met...

  18. Land surface albedo based on GOES geostationary satellite observations

    NASA Astrophysics Data System (ADS)

    Matthews, J. L.; Lattanzio, A.; Hankins, B.; Knapp, K.; Privette, J. L.

    2012-12-01

    Land surface albedo is the fraction of incoming solar radiation reflected by the land surface, and therefore can be a sensitive indicator of environmental changes. To this end, surface albedo is identified as an Essential Climate Variable (ECV) by the Global Climate Observing System (GCOS). NOAA's National Climatic Data Center (NCDC) recently adapted the Geostationary Surface Albedo (GSA; Lattanzio and Govaerts, 2010) algorithm for use with GOES data in support of a global albedo initiative led by the Sustained, Coordinated Processing of Environmental Satellite Data for Climate Monitoring (SCOPE-CM). SCOPE-CM helps coordinate ECV production responding to GCOS, WMO, and CEOS goals. The GSA algorithm was developed jointly by EUMETSAT and Joint Research Centre (JRC) using a method proposed by Pinty et al. (2000) to determine surface albedo using day-time, cloud-free geostationary observations from a single visible band. For the GOES implementation, raw GOES observations are calibrated using International Satellite Cloud Climatology Project (ISCCP) coefficients. Surface angular anisotropy is determined through the inversion of the GSA radiative transfer model using multiple geostationary images collected over a day under different illumination conditions. The inversion process requires ancillary total column ozone and water vapor values, which are acquired from the 20th Century Reanalysis V2 data set. The GSA algorithm produces a 10-day composite surface albedo map. This product is initially being developed for the years 2000-2003. Product quality is being assessed through comparisons with MODIS products as well as ground-based measurements. NCDC is producing albedo products from both GOES-E (75°W) and GOES-W (135°W). These are being merged with like products from EUMETSAT based on METEOSAT (0° and 63°E) and from JMA based on the Geostationary Meteorological Satellite System (140°E). In the near future, NOAA's Climate Data Record Program will provide the albedo product over the entire GOES period of record (1978-present).

  19. Severe Weather on the Web: Computer Lab for WEST Severe Weather Module

    E-print Network

    Jiang, Haiyan

    Severe Weather on the Web: Computer Lab for WEST Severe Weather Module Summary: Students tropical cyclone database webpage.It provides TRMM satellite observations of global tropical cyclones Weather Service-- National Weather Hazards Website: http://www.weather.gov/view/largemap.php --This

  20. Large Scale Surface Radiation Budget from Satellite Observation

    NASA Technical Reports Server (NTRS)

    Pinker, R. T.

    1995-01-01

    During the current reporting period, the focus of our work was on preparing and testing an improved version of our Surface Radiation Budget algorithm for processing the ISCCP D1 data routinely at the SRB Satellite Data Analysis Center (SDAC) at NASA Langley Research Center. The major issues addressed are related to gap filling and to testing whether observations made from ERBE could be used to improve current procedures of converting narrowband observations, as available from ISCCP, into broadband observations at the TOA. The criteria for selecting the optimal version are to be based on results of intercomparison with ground truth.

  1. Potential of Envisat Asar Observation For Surface Soil Moisture Retrieval

    NASA Astrophysics Data System (ADS)

    Caschili, Alessandro; Mancini, Marco; Troch, Peter A.; Piconi, Claudio

    In March 2002 a new Earth observation satellite will be lunched by ESA. On board is an advanced synthetic aperture radar instrument, called ASAR. It is a C band (5.3 GHz) multipolarized sensor with different incidence angle capabilities and different spatial resolutions. This offers new possibilities for Earth observations and in particular for soil moisture mapping. This paper discusses the potential of ENVISAT ASAR observation for the retrieval of surface soil moisture for bare soil. The data set used in this study was obtained at the European Microwave Signature Laboratory (EMSL), Ispra, Italy, during a dedicated soil moisture experiment (Mancini et al., 1999). Using these data the accuracy of soil moisture retrieval based on ASAR configuration and a surface scattering model is investigated. In Particular the possibilities of using the soil moisture information for assimilation in distributed hydrological models is discussed.

  2. Rb–Sr and K–Ar systems of biotite in surface environments regulated by weathering processes with implications for isotopic dating and hydrological cycles of Sr isotopes

    Microsoft Academic Search

    Gi Young Jeong; Chang-Sik Cheong; Jeongmin Kim

    2006-01-01

    Biotite is widely used for Rb–Sr and K–Ar isotopic dating and influences Sr isotope geochemistry of hydrological regimes. The isotopic system of biotite behaves diversely in response to surface weathering; i.e. the complete preservation of original Rb–Sr and K–Ar isotopic ages or dramatic reduction. In this study, we have explored the relation between the behavior of isotopic systems and complex

  3. On surface temperature, greenhouse gases, and aerosols: models and observations

    SciTech Connect

    Mitchell, J.F.B.; Davis, R.A.; Ingram, W.J.; Senior, C.A. [Hadley Centre for Climate Prediction and Research, Berkshire (United Kingdom)] [Hadley Centre for Climate Prediction and Research, Berkshire (United Kingdom)

    1995-10-01

    The effect of changes in atmospheric carbon dioxide concentrations and sulphate aerosols on near-surface temperature is investigated using a version of the Hadley Centre atmospheric model coupled to a mixed layer ocean. The scattering of sunlight by sulphate aerosols is represented by appropriately enhancing the surface albedo. On doubling atmospheric carbon dioxide concentrations, the global mean temperature increases by 5.2 K. An integration with a 39% increase in CO{sub 2}, giving the estimated change in radiative heating due to increases in greenhouse gases since 1900, produced an equilibrium warming of 2.3 K, which, even allowing for oceanic inertia, is significantly higher than the observed warming over the same period. Furthermore, the simulation suggests a substantial warming everywhere, whereas the observations indicate isolated regions of cooling, including parts of the northern midlatitude continents. The addition of an estimate of the effect of scattering by current industrial aerosols (uncertain by a factor of at least 3) leads to improved agreement with the observed pattern of changes over the northern continents and reduces the global mean warming by about 30%. Doubling the aerosol forcing produces patterns that are still compatible with the observations, but further increase leads to unrealistically extensive cooling in the midlatitudes. The diurnal range of surface temperature decreases over most of the northern extratropics on increasing CO{sub 2}, in agreement with recent observations. The addition of the current industrial aerosol had little detectable effect on the diurnal range in the model because the direct effect of reduced solar heating at the surface is approximately balanced by the indirect effects of cooling. Thus, the ratio of the reduction in diurnal range to the mean warming is increased, in closer agreement with observations. Results from further sensitivity experiments with larger increases in aerosol and CO{sub 2} are presented.

  4. Where fast weathering creates thin regolith and slow weathering creates thick regolith

    SciTech Connect

    Bazilevskaya, Ekaterina [Pennsylvania State University, University Park, PA; Lebedeva, Marina [Pennsylvania State University, University Park, PA; Pavich, Milan [U.S. Geological Survey, Reston, VA; Rother, Gernot [ORNL; Parkinson, D. Y. [Advanced Light Source, LBNL; Cole, David [Ohio State University; Brantley, S. L. [Pennsylvania State University, University Park, PA

    2012-01-01

    Weathering disaggregates rock into regolith the fractured or granular earthmaterial that sustains life on the continental land surface. Here, we investigate what controls the depth of regolith formed on ridges of two rock compositions with similar initial porosities in Virginia (USA).A priori, we predicted that the regolith on diabasewould be thicker than on granite because the dominant mineral (feldspar) in the diabase weathers faster than its granitic counterpart. However, weathering advanced 20deeper into the granite than the diabase. The 20-thicker regolith is attributed mainly to connected micron-sized pores, microfractures formed around oxidizing biotite at 20m depth, and the lower iron (Fe) content in the felsic rock. Such porosity allows pervasive advection and deep oxidation in the granite. These observations may explainwhy regolithworldwide is thicker on felsic compared tomafic rock under similar conditions. To understand regolith formationwill require better understanding of such deep oxidation reactions and how they impact fluid flow during weathering.

  5. Mountain range specific analog weather forecast model for northwest Himalaya in India

    Microsoft Academic Search

    D. Singh; A. Ganju

    2008-01-01

    Mountain range specific analog weather forecast model is developed utilizing surface weather observations of reference stations\\u000a in each mountain range in northwest Himalaya (NW-Himalaya). The model searches past similar cases from historical dataset\\u000a of reference observatory in each mountain range based on current situation. The searched past similar cases of each mountain\\u000a range are used to draw weather forecast for

  6. Rates of Chemical Weathering

    NSDL National Science Digital Library

    Michael Passow

    In this activity, students will investigate the weathering of rocks by chemical processes. They will use effervescent cleansing tablets as a model for rock, and vary surface area, temperature, and acidity to see how rapidly the "rock" dissolves. This investigation will help them understand three of the factors that affect the rate of chemical weathering and develop better understanding of how to design controlled experiments by exploring only one experimental variable at a time.

  7. The Impact of Ensemble Kalman Filter Assimilation of Near-Surface Observations on the Predictability of Atmospheric Conditions over Complex Terrain: Results from Recent MATERHORN Field Program

    NASA Astrophysics Data System (ADS)

    Pu, Z.; Zhang, H.

    2013-12-01

    Near-surface atmospheric observations are the main conventional observations for weather forecasts. However, in modern numerical weather prediction, the use of surface observations, especially those data over complex terrain, remains a unique challenge. There are fundamental difficulties in assimilating surface observations with three-dimensional variational data assimilation (3DVAR). In our early study[1] (Pu et al. 2013), a series of observing system simulation experiments was performed with the ensemble Kalman filter (EnKF) and compared with 3DVAR for its ability to assimilate surface observations with 3DVAR. Using the advanced research version of the Weather Research and Forecasting (WRF) model, results demonstrate that the EnKF can overcome some fundamental limitations that 3DVAR has in assimilating surface observations over complex terrain. Specifically, through its flow-dependent background error term, the EnKF produces more realistic analysis increments over complex terrain in general. Over complex terrain, the EnKF clearly performs better than 3DVAR, because it is more capable of handling surface data in the presence of terrain misrepresentation. With this presentation, we further examine the impact of EnKF data assimilation on the predictability of atmospheric conditions over complex terrain with the WRF model and the observations obtained from the most recent field experiments of the Mountain Terrain Atmospheric Modeling and Observations (MATERHORN) Program. The MATERHORN program provides comprehensive observations over mountainous regions, allowing the opportunity to study the predictability of atmospheric conditions over complex terrain in great details. Specifically, during fall 2012 and spring 2013, comprehensive observations were collected of soil states, surface energy budgets, near-surface atmospheric conditions, and profiling measurements from multiple platforms (e.g., balloon, lidar, radiosondes, etc.) over Dugway Proving Ground (DPG), Utah. With the near-surface observations and sounding data obtained during the MATERHORN fall 2012 field experiment, a month-long cycled EnKF analysis and forecast was produced with the WRF model and an advanced EnKF data assimilation system. Results are compared with the WRF near real-time forecasting during the same month and a set of analysis with 3DVAR data assimilation. Overall evaluation suggests some useful insights on the impacts of different data assimilation methods, surface and soil states, terrain representation on the predictability of atmospheric conditions over mountainous terrain. Details will be presented. References [1] Pu, Z., H. Zhang, and J. A. Anderson,. 'Ensemble Kalman filter assimilation of near-surface observations over complex terrain: Comparison with 3DVAR for short-range forecasts.' Tellus A, vol. 65,19620. 2013. http://dx.doi.org/10.3402/tellusa.v65i0. 19620.

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

    NASA Astrophysics Data System (ADS)

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

    2010-04-01

    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.

  9. Observation of Sea Ice Surface Thermal States Under Cloud Cover

    NASA Technical Reports Server (NTRS)

    Nghiem, S. V.; Perovich, D. K.; Gow, A. J.; Kwok, R.; Barber, D. G.; Comiso, J. C.; Zukor, Dorothy J. (Technical Monitor)

    2001-01-01

    Clouds interfere with the distribution of short-wave and long-wave radiations over sea ice, and thereby strongly affect the surface energy balance in polar regions. To evaluate the overall effects of clouds on climatic feedback processes in the atmosphere-ice-ocean system, the challenge is to observe sea ice surface thermal states under both clear sky and cloudy conditions. From laboratory experiments, we show that C-band radar (transparent to clouds) backscatter is very sensitive to the surface temperature of first-year sea ice. The effect of sea ice surface temperature on the magnitude of backscatter change depends on the thermal regimes of sea ice thermodynamic states. For the temperature range above the mirabilite (Na2SO4.10H20) crystallization point (-8.2 C), C-band data show sea ice backscatter changes by 8-10 dB for incident angles from 20 to 35 deg at both horizontal and vertical polarizations. For temperatures below the mirabilite point but above the crystallization point of MgCl2.8H2O (-18.0 C), relatively strong backwater changes between 4-6 dB are observed. These backscatter changes correspond to approximately 8 C change in temperature for both cases. The backscattering mechanism is related to the temperature which determines the thermodynamic distribution of brine volume in the sea ice surface layer. The backscatter is positively correlated to temperature and the process is reversible with thermodynamic variations such as diurnal insolation effects. From two different dates in May 1993 with clear and overcast conditions determined by the Advanced Very High Resolution Radiometer (AVHRR), concurrent Earth Resources Satellite 1 (ERS-1) C-band ice observed with increases in backscatter over first-year sea ice, and verified by increases in in-situ sea ice surface temperatures measured at the Collaborative-Interdisciplinary Cryosphere Experiment (C-ICE) site.

  10. Structure of precipitating systems over Taiwan’s complex terrain during Typhoon Morakot (2009) as revealed by weather radar and rain gauge observations

    NASA Astrophysics Data System (ADS)

    Liou, Yu-Chieng; Wang, Tai-Chi Chen; Tsai, Yi-Chun; Tang, Yu-Shuang; Lin, Pay-Liam; Lee, Yung-An

    2013-12-01

    This study documents from an observational perspective the structure of precipitation systems over the complex topography of Taiwan as Typhoon Morakot (2009) impinged on the island on 8 August 2009. An advanced multiple-Doppler radar synthesis technique particularly designed for dealing with non-flat surfaces is applied to analyze the three-dimensional wind fields over the ocean and terrain. In the northern and southern portion of the analysis domain where the mountain slope is relatively gentle and steep, respectively, the radar reflectivity measurements indicate that the precipitation systems exhibit very distinct features, namely, horizontal translation in the north and abrupt intensification in the south. While still far from the southern mountainous region, a north-south oscillation of an east-west-oriented band of strong radar reflectivity (>40 dBZ) with a horizontal span of 20 km is observed. Along the mountain slopes, the band of strong radar reflectivity has a much wider north-south extent. Both the radar and rain gauge observations show that the major precipitation is primarily confined to the windward side of the mountains. An analysis of the saturated Brunt-Väisälä frequency reveals that the upstream atmosphere is statically unstable, which implies that the lifting of the incoming convective cells by the topography will easily trigger precipitation. Thus, most of the moisture will be consumed before the air reaches the leeward side of the mountains. The long duration and the wide range of heavy precipitation in the mountainous regions resulted in a record-breaking average (over the gauges) rainfall amount of 2000 mm over 4 days. The prevailing winds approaching the mountains are from the west. The cross-barrier wind speed has a maximum (?40 m s-1) above the mountain crest that can be reasonably explained by a simplified shallow water model. The capability of applying the weather radar to provide a reliable quantitative estimate of the rainfall over a large area with high temporal and spatial resolution is demonstrated using dual-polarimetric radar data. The potential applications of the knowledge of the wind and precipitation characteristics in hydrology and other fields are addressed in this manuscript.

  11. New weather forecasting aid

    NASA Astrophysics Data System (ADS)

    A new, computerized weather analysis and display system developed by the National Oceanic and Atmospheric Administration (NOAA) is being used to provide air traffic controllers in Colorado with up-to-date information on weather systems that could affect aircraft within their control areas. The system, called PROFS (Prototype Regional Observing and Forecasting Services), was under development for four years at NOAA's Environmental Research Laboratories in Boulder, and is undergoing operational evaluation at the Federal Aviation Administration's (FAA's) Denver Air Route Traffic Control Center in Longmont, Colo. FAA officials see the new system as a first step in upgrading the weather support services for the nation's air traffic control system. Originally created to help National Weather Service personnel with their forecasting duties (Eos, April 13, 1982, p. 233), the PROFS system was specially tailored for aviation use before being installed at the Longmont center. The system uses computers to process weather data from satellites, regional radar, wind profilers, a network of automated weather stations in eastern Colorado, and other sources, some of which are not normally available to forecasters. When this information is collected and formatted, weather personnel at the center can choose from several types of visual display on their terminals, depending on what information they require. The forecasters can then make printed copies of any display and distribute them within moments to controllers who use the information to alert air traffic to storms, wind shifts, and other weather disturbances.

  12. Global Surface Thermal Inertia Derived from Dawn VIR Observations

    NASA Astrophysics Data System (ADS)

    Titus, T. N.; Becker, K. J.; Anderson, J.; Capria, M.; Tosi, F.; Prettyman, T. H.; De Sanctis, M. C.; Palomba, E.; Grassi, D.; Capaccioni, F.; Ammannito, E.; Combe, J.; McCord, T. B.; Li, J. Y.; Russell, C. T.; Raymond, C. A.

    2012-12-01

    Comparisons of surface temperatures, derived from Dawn [1] Visible and Infrared Mapping Spectrometer (VIR-MS) [2] observations , to thermal models suggest that Vesta generally has a low-thermal-inertia surface, between 25 and 35 J m^-2 K^-1 s^-½, consistent with a thick layer of fine-grain material [3]. Temperatures were calculated using a Bayesian approach to nonlinear inversion as described by Tosi et al. [4]. In order to compare observed temperatures of Vesta to model calculations, several geometric and photometric parameters must be known or estimated. These include local mean solar time, latitude, local slope, bond bolometric albedo, and the effective emissivity at 5?m. Local time, latitude, and local slope are calculated using the USGS ISIS software system [5]. We employ a multi-layered thermal-diffusion model called 'KRC' [6], which has been used extensively in the study of Martian thermophysical properties. This thermal model is easily modified for use with Vesta by replacing the Martian ephemeris input with the Vesta ephemeris and disabling the atmosphere. This model calculates surface temperatures throughout an entire Vesta year for specific sets of slope, azimuth, latitude and elevation, and a range of albedo and thermal-inertia values. The ranges of albedo and thermal inertia values create temperature indices that are closely matched to the dates and times observed by VIR. Based on observed temperatures and best-fit KRC thermal models, estimates of the annual mean surface temperatures were found to range from 176 K - 188 K for flat zenith-facing equatorial surfaces, but these temperatures can drop as low as 112 K for polar-facing slopes at mid-latitudes. [7] In this work, we will compare observed temperatures of the surface of Vesta (using data acquired by Dawn VIR-MS [2] during the approach, survey, high-altitude mapping and departure phases) to model temperature results using the KRC thermal model [5]. Where possible, temperature observations from multiple times of day or seasons will be used to better constrain the thermal inertia. The authors gratefully acknowledge the support of the Dawn Instrument, Operations, and Science Teams. This work was funded by the Dawn at Vesta Participating Science Program. [1] C.T. Russell et al. (2004) P&SS, 52, 465-489. [2] M.C. De Sanctis et al. (2011) SSRv 163, 329. [3] M.T. Capria et al. (2012) LPSC XLIII #1863 [4] F. Tosi et al. (2012) LPSC XLIII #1886. [5] J. Anderson et al. (2011) AGU Fall Meeting, #U31A-0009. [6] H.H. Kieffer H., et al. (1977) JGR, 82, 4249-4291. [7] Titus et al. (2012) EPSC, #800.

  13. Weather Measurements around Your School. Mapping Variations in Temperature and Humidity.

    ERIC Educational Resources Information Center

    Smith, David R.; And Others

    1991-01-01

    Presented is an activity where students conduct a micrometeorological study in their neighborhood using temperature, humidity measurements, and mapping skills. Included are a discussion of surface weather observations, the experiment, and directions. (KR)

  14. Assimilation of Smos Observations to Generate a Prototype SMAP Level 4 Surface and Root-Zone Soil Moisture Product

    NASA Technical Reports Server (NTRS)

    Reichle, Rolf H.; De Lannoy, Gabrielle J. M.; Crow, Wade T.; Koster, Randal D.; Kimball, John

    2012-01-01

    The Soil Moisture Active and Passive (SMAP; [1]) mission is being implemented by NASA for launch in October 2014. The primary science objectives of SMAP are to enhance understanding of land surface controls on the water, energy and carbon cycles, and to determine their linkages. Moreover, the high-resolution soil moisture mapping provided by SMAP has practical applications in weather and seasonal climate prediction, agriculture, human health, drought and flood decision support. The Soil Moisture and Ocean Salinity (SMOS; [2]) mission was launched by ESA in November 2009 and has since been observing L-band (1.4 GHz) upwelling passive microwaves. In this paper we describe our use of SMOS brightness temperature observations to generate a prototype of the planned SMAP Level 4 Surface and Root-zone Soil Moisture (L4_SM) product [5].

  15. Surface moisture and satellite microwave observations in semiarid southern Africa

    SciTech Connect

    Owe, M.; Chang, A.T.C. (NASA Goddard Space Flight Center, Greenbelt, MD (United States)); Van de Griend, A.A. (Free Univ., Amsterdam (Netherlands))

    1992-03-01

    Nimbus 7 scanning multichannel microwave radiometer 6.6-GHz passive microwave data were studied in relation to large-scale soil moisture estimates over a 3-year period in southeastern Bostwana. An extensive data base of weekly surface soil moisture measurements was used with meteorological data to estimate pixel average soil moisture on a daily basis. The influence of the vegetation canopy on the surface emissivity was studied by partitioning the data set into classes on the basis of the normalized difference vegetation index. After correcting for the vegetation optical depth, a correlation of r = 0.84 was established between the normalized brightness temperature observations and surface soil moisture for the 3-year period.

  16. High-frequency radar observations of ocean surface currents.

    PubMed

    Paduan, Jeffrey D; Washburn, Libe

    2013-01-01

    This article reviews the discovery, development, and use of high-frequency (HF) radio wave backscatter in oceanography. HF radars, as the instruments are commonly called, remotely measure ocean surface currents by exploiting a Bragg resonant backscatter phenomenon. Electromagnetic waves in the HF band (3-30 MHz) have wavelengths that are commensurate with wind-driven gravity waves on the ocean surface; the ocean waves whose wavelengths are exactly half as long as those of the broadcast radio waves are responsible for the resonant backscatter. Networks of HF radar systems are capable of mapping surface currents hourly out to ranges approaching 200 km with a horizontal resolution of a few kilometers. Such information has many uses, including search and rescue support and oil-spill mitigation in real time and larval population connectivity assessment when viewed over many years. Today, HF radar networks form the backbone of many ocean observing systems, and the data are assimilated into ocean circulation models. PMID:22809196

  17. Surface circulation in the northeast Atlantic as observed with drifters

    NASA Astrophysics Data System (ADS)

    Otto, L.; Van Aken, H. M.

    1996-04-01

    ARGOS surface drifter data from the northern parts of the northeast Atlantic over the years 1990-1993 have been analysed. The drifters had a drogue at a depth of 15 or 30 m. These data cover well over 10 drifter years. The overall drift appeared to be towards the northeast. Analysis by geographic area and by season revealed regional and temporal variations of both the mean flow and the eddy statistics. In winter the drifter velocities had a tendency towards higher values, probably due to increased wind speeds. Highest eddy kinetic energy was found in the deep Iceland Basin, where an extension of the Sub-Arctic front was observed, while the lowest eddy kinetic energy was observed over the shallower Rockall Plateau. The strongest mean surface velocities were found in the Iceland Basin, just west of the Rockall Plateau. They were connected with the Sub-Arctic front in this region. No evidence was found of westward transport of surface water across the Reykjanes Ridge towards the Irminger Sea. Two drifters were observed to leave the area across the Iceland-Faroe Ridge, flowing eastwards over the northern Faroes slope, whereas two drifters left the area through the Faroe-Shetland Channel. The small banks in the area appeared to generate anti-cyclonic surface circulation on the scale of these banks. Over the larger Rockall Bank no preference for cyclonic circulation was found. The eddy kinetic energy was highest over the deep Iceland Basin where transient eddies were found with scalar velocities well over 20 cm s -1, while the Rockall Plateau seems to be an "eddy desert". The dispersion due to the temporal variability of the Lagrangian surface velocity could well be modelled with the simple Taylor's theory, with a good fit of the data to the theoretical lines for timescales of 0.25-40 days.

  18. Titan's Surface Temperatures Maps from Cassini - CIRS Observations

    NASA Astrophysics Data System (ADS)

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

    2009-09-01

    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.

  19. ATLAS-3 correlative measurement opportunities with UARS and surface observations

    NASA Technical Reports Server (NTRS)

    Harrison, Edwin F.; Denn, Fred M.; Gibson, Gary G.

    1995-01-01

    The third ATmospheric Laboratory for Applications and Science (ATLAS-3) mission was flown aboard the Space Shuttle launched on November 3, 1994. The mission length was approximately 10 days and 22 hours. The ATLAS-3 Earth-viewing instruments provided a large number of measurements which were nearly coincident with observations from experiments on the Upper Atmosphere Research Satellite (UARS). Based on ATLAS-3 instrument operating schedules, simulations were performed to determine when and where correlative measurements occurred between ATLAS and UARS instruments, and between ATLAS and surface observations. Results of these orbital and instrument simulations provide valuable information for scientists to compare measurements between various instruments on the two satellites and at selected surface sites.

  20. Observed surface warming induced by urbanization in east China

    NASA Astrophysics Data System (ADS)

    Yang, Xuchao; Hou, Yiling; Chen, Baode

    2011-07-01

    Monthly mean surface air temperature data from 463 meteorological stations, including those from the 1981-2007 ordinary and national basic reference surface stations in east China and from the National Centers for Environmental Prediction and National Center for Atmospheric Research (NCEP/NCAR) Reanalysis, are used to investigate the effect of rapid urbanization on temperature change. These stations are dynamically classified into six categories, namely, metropolis, large city, medium-sized city, small city, suburban, and rural, using satellite-measured nighttime light imagery and population census data. Both observation minus reanalysis (OMR) and urban minus rural (UMR) methods are utilized to detect surface air temperature change induced by urbanization. With objective and dynamic station classification, the observed and reanalyzed temperature changes over rural areas show good agreement, indicating that the reanalysis can effectively capture regional rural temperature trends. The trends of urban heat island (UHI) effects, determined using OMR and UMR approaches, are generally consistent and indicate that rapid urbanization has a significant influence on surface warming over east China. Overall, UHI effects contribute 24.2% to regional average warming trends. The strongest effect of urbanization on annual mean surface air temperature trends occurs over the metropolis and large city stations, with corresponding contributions of about 44% and 35% to total warming, respectively. The UHI trends are 0.398°C and 0.26°C decade-1. The most substantial UHI effect occurred after the early 2000s, implying a significant effect of rapid urbanization on surface air temperature change during this period.

  1. Near surface magnetic domain observation with ultra-high resolution

    NASA Astrophysics Data System (ADS)

    Li, Zhenghua; Li, Xiang; Liu, Dongping; Saito, H.; Ishio, S.

    2014-09-01

    Near field magnetic force microscopy (NF-MFM) has been demonstrated to locally observe the magnetic fine structures in nanosized recording bits at an operating distance of 1 nm. The nanoscale magnetic domains, the polarity of surface magnetic charges, as well as the 3D magnetic fields leaking from the bits are investigated via NF-MFM with a soft NiFe tip. A Fourier analysis of the images suggests that the magnetic moment can be determined locally in a volume as small as 5 nanometers. The NF-MFM is crucial to the analysis of surface magnetic features and allows a wide range of future applications, for example, in data storage and biomedicine.Near field magnetic force microscopy (NF-MFM) has been demonstrated to locally observe the magnetic fine structures in nanosized recording bits at an operating distance of 1 nm. The nanoscale magnetic domains, the polarity of surface magnetic charges, as well as the 3D magnetic fields leaking from the bits are investigated via NF-MFM with a soft NiFe tip. A Fourier analysis of the images suggests that the magnetic moment can be determined locally in a volume as small as 5 nanometers. The NF-MFM is crucial to the analysis of surface magnetic features and allows a wide range of future applications, for example, in data storage and biomedicine. Electronic supplementary information (ESI) available. See DOI: 10.1039/c4nr02215g

  2. Experimental Observation of Bohr's Nonlinear Fluidic Surface Oscillation

    E-print Network

    Songky Moon; Younghoon Shin; Hojeong Kwak; Juhee Yang; Sang-Bum Lee; Soyun Kim; Kyungwon An

    2015-04-20

    Niels Bohr in the early stage of his career developed a nonlinear theory of fluidic surface oscillation in order to study surface tension of liquids. His theory includes the nonlinear interaction between multipolar surface oscillation modes, surpassing the linear theory of Rayleigh and Lamb. It predicts a specific normalized magnitude of $0.41\\dot{6}\\eta^2$ for an octapolar component, nonlinearly induced by a quadrupolar one with a magnitude of $\\eta$ much less than unity. No experimental confirmation on this prediction has been reported. Nonetheless, accurate determination of multipolar components is important as in optical fiber spinning, film blowing and recently in optofluidic microcavities for ray and wave chaos studies and photonics applications. Here, we report experimental verification of his theory. By using optical forward diffraction, we measured the cross-sectional boundary profiles at extreme positions of a surface-oscillating liquid column ejected from a deformed microscopic orifice. We obtained a coefficient of $0.42\\pm0.08$ consistently under various experimental conditions. We also measured the resonance mode spectrum of a two-dimensional cavity formed by the cross-sectional segment of the liquid jet. The observed spectra agree well with wave calculations assuming a coefficient of $0.415\\pm0.010$. Our measurements establish the first experimental observation of Bohr's hydrodynamic theory.

  3. TIMS observations of surface emissivity in HAPEX-Sahel

    NASA Technical Reports Server (NTRS)

    Schmugge, Thomas; Hook, Simon; Kahle, Anne

    1995-01-01

    The Thermal Infrared Multispectral Scanner (TIMS) was flown on the NASA C-130 aircraft for a series of 12 flights during HAPEX-Sahel at altitudes ranging from 0.25 to 6 km (0.6 to 15 m resolution). TIMS provides coverage of the 8 to 12 micrometer thermal infrared band in 6 contiguous channels. Thus it is possible to observe the spectral behavior of the surface emissivity over this wavelength interval.

  4. A systematic evaluation of the lagged effects of spatiotemporally relative surface weather types on wintertime cardiovascular-related mortality across 19 US cities

    NASA Astrophysics Data System (ADS)

    Lee, Cameron C.

    2015-02-01

    Previous research using varying methods has shown that the day-to-day variability in cardiovascular (CV)-related mortality is correlated with a number of different meteorological variables, though these relationships can vary geographically. This research systematically examines the relationship between anomalous winter CV-related mortality and geographically and seasonally relative multivariate surface weather types derived from a recently developed gridded weather typing classification (GWTC) for cities in varying climate regions of the United States of America (USA). Results indicate that for all locations examined, during winter, a dry and cool (DC) weather type is significantly related to increased CV-related mortality, especially in the 2 weeks immediately after it occurs, with no apparent mortality displacement. Across the USA as a whole, the peak of this relationship is a 4.1% increase in CV-related mortality at a lag of 3 days. Spike days in CV-related mortality show similar trends, being over 50% more likely 2 to 4 days after the DC type occurs. A humid and warm (HW) weather type exhibited a significant and opposite relationship to that of DC. While these results for DC and HW were statistically significant at every location examined, the magnitudes were larger in the warmer locations. Among other weather types, Warm Front Passages (WFP) were also related to significant increases in CV-related mortality, especially 1 day after they occurred. Though this link was much more varied geographically than results found with DC or HW, it suggests that sequences of multiple DC days followed by WFP may result in increased CV-related mortality.

  5. Structure-dependent degradation of polar compounds in weathered oils observed by atmospheric pressure photo-ionization hydrogen/deuterium exchange ultrahigh resolution mass spectrometry.

    PubMed

    Islam, Ananna; Kim, Donghwi; Yim, Un Hyuk; Shim, Won Joon; Kim, Sunghwan

    2015-10-15

    The resin fractions of fresh mixtures of three oils spilled during the M/V Hebei Spirit oil spill, as well as weathered oils collected at weathering stages II and IV from the oil spill site were analyzed and compared by atmospheric pressure photo-ionization hydrogen/deuterium exchange mass spectrometry (HDX MS). The significantly decreased abundance of N(+) and [N-H+D](+) ions suggested that secondary and tertiary amine-containing compounds were preferentially degraded during the early stage of weathering. [N+H](+) and [N+D](+) ions previously attributed to pyridine-type compounds degraded more slowly than secondary and tertiary amine-containing compounds. The preferential degradation of nitrogen-containing compounds was confirmed by photo-degradation experiments using 15 standard compounds. In addition, significant increases of [S1O1+H](+) and [S1O1+D](+) ions with higher DBE values were observed from fresh oil mixtures as compared to stages II and IV samples, and that could be linked with the decrease of higher DBE compounds of the S1 class. This study presented convincing arguments and evidence demonstrating that secondary and tertiary amines were more vulnerable to photo-degradation than compounds containing pyridine, and hence, preferential degradation depending on chemical structures must be considered in the production of hazardous or toxic components. PMID:25913675

  6. Observation of dynamic water microadsorption on Au surface

    SciTech Connect

    Huang, Xiaokang, E-mail: xiaokang.huang@tqs.com; Gupta, Gaurav; Gao, Weixiang; Tran, Van; Nguyen, Bang; McCormick, Eric; Cui, Yongjie; Yang, Yinbao; Hall, Craig; Isom, Harold [TriQuint Semiconductor, Inc., 500 W Renner Road, Richardson, Texas 75080 (United States)

    2014-05-15

    Experimental and theoretical research on water wettability, adsorption, and condensation on solid surfaces has been ongoing for many decades because of the availability of new materials, new detection and measurement techniques, novel applications, and different scales of dimensions. Au is a metal of special interest because it is chemically inert, has a high surface energy, is highly conductive, and has a relatively high melting point. It has wide applications in semiconductor integrated circuitry, microelectromechanical systems, microfluidics, biochips, jewelry, coinage, and even dental restoration. Therefore, its surface condition, wettability, wear resistance, lubrication, and friction attract a lot of attention from both scientists and engineers. In this paper, the authors experimentally investigated Au{sub 2}O{sub 3} growth, wettability, roughness, and adsorption utilizing atomic force microscopy, scanning electron microscopy, reflectance spectrometry, and contact angle measurement. Samples were made using a GaAs substrate. Utilizing a super-hydrophilic Au surface and the proper surface conditions of the surrounding GaAs, dynamic microadsorption of water on the Au surface was observed in a clean room environment. The Au surface area can be as small as 12??m{sup 2}. The adsorbed water was collected by the GaAs groove structure and then redistributed around the structure. A model was developed to qualitatively describe the dynamic microadsorption process. The effective adsorption rate was estimated by modeling and experimental data. Devices for moisture collection and a liquid channel can be made by properly arranging the wettabilities or contact angles of different materials. These novel devices will be very useful in microfluid applications or biochips.

  7. Diurnal Variations of Titan's Surface Temperatures From Cassini -CIRS Observations

    NASA Astrophysics Data System (ADS)

    Cottini, Valeria; Nixon, Conor; Jennings, Don; Anderson, Carrie; Samuelson, Robert; Irwin, Patrick; Flasar, F. Michael

    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.

  8. Probing surface properties of Jupiter Trojans by polarimetric observations

    NASA Astrophysics Data System (ADS)

    Belskaya, I.; Bagnulo, S.; Stinson, A.; Christou, A.; Muinonen, K.

    2014-07-01

    We present the first polarimetric observations of six Jupiter Trojans, namely (588) Achilles, (1583) Antilochus, (3548) Eurybates, (4543) Phoinix, (6545) 1986 TR_6, and (21601) 1998 XO_{89}. All these objects belong to the L4 population of Jupiter Trojans and have diameters in the range of 50-160 km (Grav et al. 2011). The observations were carried out in 2013 at ESO VLT. Each object was observed at 3-4 different phase angles in the phase-angle range from 7 deg up to 11-12 deg, the largest possible phase angles in the ground-based observations of Trojans. Observations were made in the R band with a typical accuracy of 0.05 %. We have measured negative polarization branch for each object with polarization minima varying from -1 % to -1.3 %. The polarization-phase-angle behavior of the observed Trojans is found to be very similar to that of some low-albedo main-belt asteroids, in particular, the P-type asteroids. We compare photometric and polarimetric phase dependencies of Trojans to the phase curves of inner and outer Solar System bodies. Possible relationships of phase-curve parameters with albedos and spectral properties are investigated. Constraints on the surface properties of Jupiter Trojans from the polarimetric observations are discussed.

  9. Prediction versus Projection: How weather forecasting and

    E-print Network

    Howat, Ian M.

    Context: Global http://data.giss.nasa.gov/ #12;Numerical Weather Prediction Collect ObservationsPrediction versus Projection: How weather forecasting and climate models differ. Aaron B. Wilson Weather and Climate? · Weather*: The state of the atmosphere, mainly with respect to its effects upon life

  10. Pre-Observational Evolution of Surface Temperature in Romania as Inferred from Borehole Temperature Measurements

    NASA Astrophysics Data System (ADS)

    Demetrescu, Crisan; Tumanian, Maria; Dobrica, Venera; Mares, Constantin; Mares, Ileana

    2012-01-01

    Temperature data from nine boreholes in the Carpathian orogen in Romania were used to obtain information on the ground surface temperature history (GSTH) in the last 250 years. The temperature measurements were taken with a thermistor probe (sensitivity in the 10 mK range) using the stop-and-go technique, at 10 m intervals, in the depth range of 20-580 m. The least squares inverse modelling approach of Tarantola and Valette (J Geophys 50:159-170, 1982) was used to infer the GSTH. Long-term air temperature records available from the Romanian weather station network were used as a comparison term for the first 100-150 years of the GSTH, and as a forcing function in a POM-SAT model that combines borehole temperature profiles (BTPs) and meteorological time series (surface air temperature, SAT) to produce information on the so-called pre-observational mean (POM). Results from a global circulation model for the Romanian area are incorporated in the discussion as well.

  11. Satellite Based Mapping of Land Surface ET using MODIS and Alternate Surface Meteorological Inputs from AMSR-E, Reanalysis, and Surface Weather Stations

    Microsoft Academic Search

    Q. Mu; L. A. Jones; J. S. Kimball; S. W. Running

    2007-01-01

    Regional evapotranspiration (ET), including water loss from plant transpiration and soil evaporation, is essential to understanding interactions between land-atmosphere surface energy and water balances. Vapor pressure deficit (VPD) and surface air temperature are key variables for stomatal conductance and ET estimation. We developed an algorithm to estimate ET using a modified Penman-Monteith approach driven by MODIS derived vegetation data and

  12. Land surface thermal environment during heat wave event measured by satellite observation

    NASA Astrophysics Data System (ADS)

    Chen, Feng; Yang, Song

    2014-11-01

    In summer 2013, mainly from July to August, most parts of China continued to experience an unusually severe heat wave with exceptionally high air temperatures, based on the records measured at meteorological stations. As a supplement to the weather station networks, remotely sensed observation can quantify detailed variation of surface temperature at relatively high spatial resolution, owing to its ability to provide a complete and homogeneous data sources. In addition to the GHCN CAMS gridded land air surface temperature, land surface temperature products of MODIS including MOD11C3/MYD11C3 and MOD11A2/MYD11A2 were used to evaluate the anomaly of summertime thermal environment over the South China in 2013. To investigate the impacts of heat wave event on built environment, the MODIS Land Cover Type yearly product (MCD12Q1) was collected. Regional thermal anomaly was observed in both air and surface temperature measurements, especially for August. Statistics based on MOD11A2/MYD11A2 shows the spatio-temporal variation of land surface temperature at regional scale, and the heterogeneous characteristics in diurnal cycle are also shown. Compared with other types, the urban and built-up generally presents larger surface temperature at daytime. Detailed analyses were further conducted for three selected regions roughly covering the Yangtze River Delta, the Pearl River Delta, and the areas around Wuhan City respectively. Findings indicate that urban and built-up exhibits more distinct thermal contrast to its surroundings at daytime, in contrast to the situation at nighttime. This thermal contrast was defined as surface urban heat island intensity (UHII) calculated using a newly proposed procedure, in this paper. The UHII shows both time- and geography-dependent variations. Meanwhile, the UHII over medium and small cities was even more obvious and larger than that over megalopolitan areas. These preliminary findings suggest that land use and land cover changes as a consequence of rapid urbanization possibly gives positive feedback to warming anomaly during heat wave event. The exacerbated warming of built-up environment, not only over megalopolitan areas but also over medium and small cities, deserves our attention in urban management.

  13. Antarctic cloud and surface properties: Satellite observations and climate implications

    NASA Astrophysics Data System (ADS)

    Berque, Joannes

    2004-12-01

    The radiative effect of clouds in the Antarctic, although small at the top of the atmosphere, is very large within the surface-atmosphere system, and influences a variety of climate processes on a global scale. Because field observations are difficult in the Antarctic interior, satellite observations may be especially valuable in this region; but the remote sensing of clouds and surface properties over the high ice sheets is problematic due to the lack of radiometric contrast between clouds and the snow. A radiative transfer model of the Antarctic snow-atmosphere system is developed, and a new method is proposed for the examination of the problem of cloud properties retrieval from multi-spectral measurements. Key limitations are identified, and a method is developed to overcome them. Using data from the Advanced Very High Resolution Radiometer (AVHRR) onboard National Oceanic and Atmospheric Agency (NOAA) polar orbiters, snow grain size is retrieved over the course of a summer. Significant variability is observed, and it appears related to major precipitation events. A radiative transfer model and a single-column model are used to evaluate the impact of this variability on the Antarctic plateau. The range of observed grain size induces changes of up to 30 Wm-2 on the absorption of shortwave radiation in both models. Cloud properties are then retrieved in summertime imagery of the South Pole. Comparison of model to observations over a wide range of cloud optical depths suggests that this method allows the meaningful interpretation of AVHRR radiances in terms of cloud properties over the Antarctic plateau. The radiative effect of clouds at the top of the atmosphere is evaluated over the South Pole with ground-based lidar observations and data from Clouds and the Earth Radiant Energy System (CERES) onboard NASA's Terra satellite. In accord with previous work, results indicate that the shortwave and net effect are one of cooling throughout the year, while the longwave effect is one of cooling in winter and slight warming in summer.

  14. Surface contour radar observations of the directional wave spectrum during Fasinex

    NASA Technical Reports Server (NTRS)

    Walsh, E. J.; Hancock, D. W., III; Hines, D. E.; Swift, R. N.; Scott, J. F.

    1988-01-01

    The surface control radar (SCR), a 36-GHz computer-controlled airborne radar which generates a false-color coded elevation map of the sea surface below the aircraft in real time, is described. The SCR turned out to be ideal for documenting the wave spectra during Fasinex (the Frontal Air-Sea Interaction Experiment) due to its high spatial resolution and rapid mapping capability over extensive areas. Synoptic weather maps for February 15-18, 1986 are presented.

  15. Coupled atmosphere and land-surface assimilation of surface observations with a single column model and ensemble data assimilation

    NASA Astrophysics Data System (ADS)

    Rostkier-Edelstein, Dorita; Hacker, Joshua P.; Snyder, Chris

    2014-05-01

    Numerical weather prediction and data assimilation models are composed of coupled atmosphere and land-surface (LS) components. If possible, the assimilation procedure should be coupled so that observed information in one module is used to correct fields in the coupled module. There have been some attempts in this direction using optimal interpolation, nudging and 2/3DVAR data assimilation techniques. Aside from satellite remote sensed observations, reference height in-situ observations of temperature and moisture have been used in these studies. Among other problems, difficulties in coupled atmosphere and LS assimilation arise as a result of the different time scales characteristic of each component and the unsteady correlation between these components under varying flow conditions. Ensemble data-assimilation techniques rely on flow dependent observations-model covariances. Provided that correlations and covariances between land and atmosphere can be adequately simulated and sampled, ensemble data assimilation should enable appropriate assimilation of observations simultaneously into the atmospheric and LS states. Our aim is to explore assimilation of reference height in-situ temperature and moisture observations into the coupled atmosphere-LS modules(simultaneously) in NCAR's WRF-ARW model using the NCAR's DART ensemble data-assimilation system. Observing system simulation experiments (OSSEs) are performed using the single column model (SCM) version of WRF. Numerical experiments during a warm season are centered on an atmospheric and soil column in the South Great Plains. Synthetic observations are derived from "truth" WRF-SCM runs for a given date,initialized and forced using North American Regional Reanalyses (NARR). WRF-SCM atmospheric and LS ensembles are created by mixing the atmospheric and soil NARR profile centered on a given date with that from another day (randomly chosen from the same season) with weights drawn from a logit-normal distribution. Three types of one-week long numerical experiments are performed: (a) free ensemble runs; (b) ensemble assimilation that directly impacts the atmospheric-state vector only; (c) ensemble assimilation that directly impacts the coupled atmospheric-LS-state vector. The WRF-SCM is run in two modes: with and without inclusion of externally imposed horizontal advection terms in the atmospheric column (derived from the NARR, too). Preliminary examination of analyses and 30-min forecasts of reference height temperature and moisture, soil temperature and moisture at four depths (0.05m, 0.25m, 0.7m and 1.5m), fluxes at the surface, and planetary boundary layer (PBL) height shows that: 1. Horizontal advection is important to the realism of PBL heights and fluxes in the "truth", and affects the depth of influence of the assimilation on the soil state; a deeper effect (that could be non-realistic) is more often observed when advection is not included. 2. Inclusion of soil variables in the state vector can be beneficial to estimates of soil temperature and moisture,of moisture- and net latent heat fluxes at the surface, and of atmospheric variables (for the latter especially when no advection is included), However, no benefit is observed on PBL heights. Further analysis and improvement of the WRF-SCM/DART system (in particular the treatment of advection) is under way.

  16. Assimilation of Satellite-Derived Skin Temperature Observations into Land Surface Models

    NASA Technical Reports Server (NTRS)

    Reichle, Rolf H.; Kumar, Sujay V.; Mahanama, P. P.; Koster, Randal D.; Liu, Q.

    2010-01-01

    Land surface (or "skin") temperature (LST) lies at the heart of the surface energy balance and is a key variable in weather and climate models. Here we assimilate LST retrievals from the International Satellite Cloud Climatology Project (ISCCP) into the Noah and Catchment (CLSM) land surface models using an ensemble-based, off-line land data assimilation system. LST is described very differently in the two models. A priori scaling and dynamic bias estimation approaches are applied because satellite and model LST typically exhibit different mean values and variability. Performance is measured against 27 months of in situ measurements from the Coordinated Energy and Water Cycle Observations Project at 48 stations. LST estimates from Noah and CLSM without data assimilation ("open loop") are comparable to each other and superior to that of ISCCP retrievals. For LST, RMSE values are 4.9 K (CLSM), 5.6 K (Noah), and 7.6 K (ISCCP), and anomaly correlation coefficients (R) are 0.62 (CLSM), 0.61 (Noah), and 0.52 (ISCCP). Assimilation of ISCCP retrievals provides modest yet statistically significant improvements (over open loop) of up to 0.7 K in RMSE and 0.05 in anomaly R. The skill of surface turbulent flux estimates from the assimilation integrations is essentially identical to the corresponding open loop skill. Noah assimilation estimates of ground heat flux, however, can be significantly worse than open loop estimates. Provided the assimilation system is properly adapted to each land model, the benefits from the assimilation of LST retrievals are comparable for both models.

  17. Material properties for mantle convection consistent with observed surface fields

    NASA Technical Reports Server (NTRS)

    Kaula, W. M.

    1980-01-01

    An attempt is made to derive constraints on mantle convection from observed surface fields: plate velocities, gravity, topography and heat flow. The spherical harmonic spectra of the fields are expressed in terms of a spectral magnitude and slope, and requirements for the minimal representation of the equations for mantle convection are discussed. The effects of the boundary layer represented by the surface fields on convection at the mantle surface and at deeper levels are then examined, and a mean value of the effective mantle viscosity of approximately 10 to the 23rd g/cm per sec is obtained, together with values of 10 to the 8th and 10 to the 7th for the Rayleigh numbers of whole mantle and upper mantle convection, respectively. Consideration is then given to the compositional, thermal and rheological aspects of mantle convection, and it is pointed out that constraints on the depth and other properties of convection will require more detailed modeling using the relationships between the harmonic coefficients of the surface fields.

  18. STATISTICAL CORRELATIONS OF SURFACE WIND DATA: A COMPARISON BETWEEN A NATIONAL WEATHER SERVICE STATION AND A NEARBY AEROMETRIC MONITORING NETWORK

    EPA Science Inventory

    This report presents a statistical analysis of wind data collected at a network of stations in the Southeast Ohio River Valley. The purpose of this study is to determine the extent to which wind measurements made by the National Weather Service (NWS) station at the Tri-State Airp...

  19. Modeling and surface observations of arsenic dispersion from a large Cu-smelter in southwestern Europe

    NASA Astrophysics Data System (ADS)

    Chen, Bing; Stein, Ariel F.; Castell, Nuria; de la Rosa, Jesus D.; Sanchez de la Campa, Ana M.; Gonzalez-Castanedo, Yolanda; Draxler, Roland R.

    2012-03-01

    Arsenic is a toxic element for human health. Consequently, a mean annual target level for arsenic at 6 ng m-3 in PM10 was established by the European Directive 2004/107/CE to take effect January 2013. Cu-smelters can contribute to one-third of total emissions of arsenic in the atmosphere. Surface observations taken near a large Cu-smelter in the city of Huelva (Spain) show hourly arsenic concentrations in the range of 0-20 ng m-3. The arsenic peaks of 20 ng m-3 are higher than values normally observed in urban areas around Europe by a factor of 10. The Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT) model has been employed to predict arsenic emissions, transport, and dispersion from the Cu-smelter. The model utilized outputs from different meteorological models and variations in the model physics options to simulate the uncertainty in the dispersion of the arsenic plume. Modeling outputs from the physics ensemble for each meteorological model driving HYSPLIT show the same number of arsenic peaks. HYSPLIT coupled with the Weather Research and Forecasting (WRF-ARW) meteorological output predicted the right number of peaks for arsenic concentration at the observation site. The best results were obtained when the WRF simulation used both four-dimensional data assimilation and surface analysis nudging. The prediction was good in local sea breeze circulations or when the flow was dominated by the synoptic scale prevailing winds. However, the predicted peak was delayed when the transport and dispersion was under the influence of an Atlantic cyclone. The calculated concentration map suggests that the plume from the Cu-smelter can cause arsenic pollution events in the city of Huelva as well as other cities and tourist areas in southwestern Spain.

  20. Observing the Zeeman effect of topological surface state

    NASA Astrophysics Data System (ADS)

    Fu, Yingshuang; Hanaguri, Tetsuo; Yamamoto, Shuhei; Igarashi, Kyushiro; Kawamura, Minoru; Kohsaka, Yuhki; Iwaya, Katsuya; Takagi, Hidenori; Sasagawa, Takao

    2015-03-01

    Dirac fermions in the topological surface state (TSS) have helical spin textures. This is different from those in graphene, which are both valley and spin degenerated. The spin degeneracy can be lifted by Zeeman effect, which is manifested as a spin-splitting of Landau levels (LLs). In the case of TSS, LLs instead should exhibit monotonic shift with magnetic field since the spin degeneracy is lacking. While the Zeeman splitting of LLs in graphene has been successfully observed, the expected features in TSS still lack experimental proof. With scanning tunneling microscopy and spectroscopy, we observed the Zeeman shifting of zeroth LL in the TSS of Bi2Se3 and Sb2Te2Se unambiguously. Moreover, we exclude the extrinsic influence on LL shifting from potential variations and the nonideal band dispersions of TSS in actual materials by modeling. The surface g factor in Sb2Te2Se and Bi2Se3 is estimated as -10 and 16, respectively. This observation indicates that the g factor of TSS is significantly material dependent, which may be related to the atomic orbital character of the compound.

  1. Observations of Radiative Cooling By Nitric Oxide and Carbon Dioxide in the E and F Regions: Implications for Space Weather and Space Climate

    NASA Astrophysics Data System (ADS)

    Mlynczak, M. G.; Hunt, L. A.; Russell, J. M., III

    2014-12-01

    Infrared emission by nitric oxide (NO, 5.3 um), carbon dioxide (CO2, 15 um), and atomic oxygen (O, 63 um) is the mechanism for radiative cooling of the thermosphere. Heat conduction transports energy from the warmer, higher layers of the thermosphere to lower layers where CO2 and NO ultimately radiate the energy. These radiative processes play a large role in governing the neutral temperature of the ionosphere E and F regions. The SABER instrument on the NASA TIMED satellite has been observing radiative cooling by NO and CO2 for 13 years. Substantial variability in the radiative cooling is observed on timescales ranging from one day to the 11-year solar cycle. Harmonics of the annual cycle are evident in the CO2 cooling rates, implying strong coupling to the lower atmosphere. Harmonics of the solar rotation period are evident in the NO cooling, but only during solar minimum conditions. To date the NO cooling data have been helpful in understanding space weather forecasts and the interaction of co-rotating interaction regions with the ionosphere. The cooling rate data will be reviewed in light of their observed variability over the past 13 years, including the implications for variations in the thermal structure of the E and F regions. The potential for development of proxies and empirical models of the NO and CO2 emissions will also be presented. Such models could become part of an overall space weather forecasting tool.

  2. Observation of 2nd Schumann eigenmode on Titan's surface

    NASA Astrophysics Data System (ADS)

    Béghin, C.; Wattieaux, G.; Grard, R.; Hamelin, M.; Lebreton, J. P.

    2013-04-01

    This works presents the results obtained from an updated data analysis of the observations of Extremely Low Frequency (ELF) electromagnetic waves performed with the HASI-PWA (Huygens Atmospheric Structure and Permittivity, Wave and Altimetry) instrumentation after Huygens Probe landing on Titan surface in January 2005. The most significant signals observed at around 36 Hz throughout the descent in the atmosphere have been extensively analyzed for several years, and subsequently interpreted as the signature of a Schumann resonance, although the latter exhibits atypical peculiarities compared with those known on Earth. The usual depicting methods of space wave data used so far could not allow retrieving the presence of weak signals when Huygens was at rest for 32 min on Titan's surface. Whereas the expected signal seems hidden within the instrumental noise, we show that a careful statistical analysis of the amplitude distribution of the 418 spectral density samples of the 36 Hz line reveals abnormal characteristics compared to other frequencies. This behavior is shown to occur under propitious circumstances due to the characteristics of the onboard data conversion processes into digital telemetry counts, namely 8-bit dynamic after logarithm compression of the DFT (Discrete Fourier Transform) of ELF waveforms. Since this phenomenon is observed only at the frequency bin around 36 Hz, we demonstrate that the Schumann resonance, seen in the atmosphere within the same band, is still present on the surface, albeit with a much smaller amplitude compared to that measured before and a few seconds after the impact, because the electric dipole is thought to have been stabilized ten seconds later almost horizontally until the end of the measurements.

  3. Observation of 2nd Schumann eigenmode on Titan's surface

    NASA Astrophysics Data System (ADS)

    Béghin, C.; Wattieaux, G.; Grard, R.; Hamelin, M.; Lebreton, J. P.

    2013-10-01

    This work presents the results obtained from an updated data analysis of the observations of extremely low frequency (ELF) electromagnetic waves performed with the HASI-PWA (Huygens Atmospheric Structure and Permittivity, Wave and Altimetry) instrumentation after Huygens Probe landing on Titan's surface in January 2005. The most significant signals observed at around 36 Hz throughout the descent in the atmosphere have been extensively analyzed for several years, and subsequently interpreted as the signature of a Schumann resonance, although the latter exhibits atypical peculiarities compared with those known on Earth. The usual depicting methods of space wave data used so far could not allow for retrieving the presence of weak signals when Huygens was at rest for 32 min on Titan's surface. Whereas the expected signal seems hidden within the instrumental noise, we show that a careful statistical analysis of the amplitude distribution of the 418 spectral density samples of the 36 Hz line reveals abnormal characteristics compared to other frequencies. This behavior is shown to occur under propitious circumstances due to the characteristics of the onboard data conversion processes into digital telemetry counts, namely 8-bit dynamic after logarithm compression of the DFT (Discrete Fourier Transform) of ELF waveforms. Since this phenomenon is observed only at the frequency bin around 36 Hz, we demonstrate that the Schumann resonance, seen in the atmosphere within the same band is still present on the surface, albeit with a much smaller amplitude compared to that measured before and a few seconds after the impact, because the electric dipole is thought to have been stabilized ten seconds later almost horizontally until the end of the measurements.

  4. Experimental observation of dark solitons on the surface of water.

    PubMed

    Chabchoub, A; Kimmoun, O; Branger, H; Hoffmann, N; Proment, D; Onorato, M; Akhmediev, N

    2013-03-22

    We present the first ever observation of dark solitons on the surface of water. It takes the form of an amplitude drop of the carrier wave which does not change shape in propagation. The shape and width of the soliton depend on the water depth, carrier frequency, and the amplitude of the background wave. The experimental data taken in a water tank show an excellent agreement with the theory. These results may improve our understanding of the nonlinear dynamics of water waves at finite depths. PMID:25166807

  5. Isotopic Excesses of Proton-rich Nuclei Related to Space Weathering Observed in a Gas-rich Meteorite Kapoeta

    NASA Astrophysics Data System (ADS)

    Hidaka, Hiroshi; Yoneda, Shigekazu

    2014-05-01

    The idea that solar system materials were irradiated by solar cosmic rays from the early Sun has long been suggested, but is still questionable. In this study, Sr, Ba, Ce, Nd, Sm, and Gd isotopic compositions of sequential acid leachates from the Kapoeta meteorite (howardite) were determined to find systematic and correlated variations in their isotopic abundances of proton-rich nuclei, leading to an understanding of the irradiation condition by cosmic rays. Significantly large excesses of proton-rich isotopes (p-isotopes), 84Sr, 130Ba, 132Ba, 136Ce, 138Ce, and 144Sm, were observed, particularly in the first chemical separate, which possibly leached out of the very shallow layer within a few ?m from the surface of regolith grains in the sample. The results reveal the production of p-isotopes through the interaction of solar cosmic rays with the superficial region of the regolith grains before the formation of the Kapoeta meteorite parent body, suggesting strong activity in the early Sun.

  6. Planetary Weather

    NSDL National Science Digital Library

    This lesson plan is part of the DiscoverySchool.com lesson plan library for grades 6-8. It focuses on the weather conditions on other planets. After learning more about weather patterns, students research the weather on a given planet and create a visual display of the conditions there. It includes objectives, materials, procedures, discussion questions, evaluation ideas, suggested readings, and vocabulary. There are videos available to order which complement this lesson, and links to teaching tools for making custom quizzes, worksheets, puzzles and lesson plans.

  7. Geologic interpretation of new observations of the surface of Venus

    NASA Technical Reports Server (NTRS)

    Saunders, R. S.; Malin, M. C.

    1977-01-01

    New radar observations of the surface of Venus provide further evidence of a diverse and complex geologic evolution. The radar bright feature 'Beta' (24 deg N, 85 deg W) is seen to be a 700 km diameter region elevated a maximum of approximately 10 km relative to its surroundings with a 60 x 90 km wide depression at its summit. 'Beta' is interpreted to be a large volcanic construct, analogous to terrestrial and Martian shield volcanoes. Two large, quasi-circular areas of low reflectivity, examples of a class of features interpreted to be impact basins by previous investigators who were without the benefit of actual topographic information, are shown in altimetry maps to be depressions. Thus the term 'basin' can be applied, although we urge a non-genetic usage until more complete understanding of their origin is achieved through analysis of future observations.

  8. Stable runoff and weathering fluxes into the oceans over Quaternary climate cycles

    NASA Astrophysics Data System (ADS)

    von Blanckenburg, Friedhelm; Bouchez, Julien; Ibarra, Daniel E.; Maher, Kate

    2015-07-01

    Throughout the Quaternary period, the Earth’s surface has been subject to large changes in temperature and precipitation associated with fluctuations between glacial and interglacial states that have affected biogeochemical cycling. However, the effect of these climate oscillations on weathering is debated, with climate modelling efforts using empirical relationships between measures of climate and weathering suggesting minimal changes in global weathering rates between these two climate states. The ratio of the cosmogenic isotope 10Be, which is produced in the atmosphere and deposited to the oceans and the land surface, to 9Be, which is introduced to the oceans by the riverine silicate weathering flux, can be used to track relative weathering fluxes. Here we apply this proxy to marine sediment beryllium records spanning the past two million years, and find no detectable shifts in inputs from global silicate weathering into the oceans. Using climate model simulations of the Last Glacial Maximum along with a model for silicate weathering, we find that there was large regional variability in runoff between glacial and interglacial periods, but that this regional variability was insufficient to shift global weathering fluxes. We suggest that this stability in weathering explains the observation that the removal of CO2 from the atmosphere by silicate weathering has been in approximate balance with CO2 degassing over the past 600,000 years.

  9. Basalt Weathering Rates Across Scales

    NASA Astrophysics Data System (ADS)

    Navarresitchler, A.; Brantley, S.

    2006-12-01

    Weathering of silicate minerals is a known sink for atmospheric CO2. An estimated 30%-35% of the consumption of CO2 from continental silicate weathering can be attributed to basalt weathering (Dessert et al., 2003). To assess basalt weathering rates we examine weathering advance rates of basalt (w, mm/yr) reported at four scales: denudation rates from basalt watersheds (tens of kilometers), rates of soil formation from soil profiles developed on basaltic parent material of known age (meters), rates of weathering rind formation on basalt clasts (centimeters), and laboratory dissolution rates (millimeters). Basalt weathering advance rates calculated for watersheds range between 0.36 and 9.8x10-3 mm/yr. The weathering advance rate for a basalt soil profile in Hawaii is 8.0x10-3 mm/yr while advance rates for clasts range from 5.6x10-6 to 2.4x10-4 mm/yr. Batch and mixed flow laboratory experiments performed at circum- neutral pH yield advance rates of 2.5x10^{-5} to 3.4x10-7 mm/yr when normalized to BET surface area. These results show increasing advance rates with both increasing scale (from laboratory to watersheds) and increasing temperature. If we assume that basalt weathers at an intrinsic rate that applies to all scales then we conclude that variations in weathering advance rates arise from variations in surface area measurement at different scales (D); therefore, basalt weathering is a fractal system. We measure a fractal dimension (dr) of basalt weathering of 2.2. For Euclidean geometries, measured surface area does not vary with the scale at which it is measured and dr equals 2. For natural surfaces, surface area is related to the scale at which it is measured. As scale increases, the minimum size of the surface irregularities that are measurable also increases. The ratio between BET and geometric normalized laboratory dissolution rates has been defined as a roughness parameter, ?, which ranges from ~10-100. We extend the definition of this roughness parameter to compare weathering advance rates at varying scales. Given that, w=10^{-3.7}D^{0.23} we can use the fractal dimension of basalt weathering to define the roughness factor for basalt weathering as, ?=wD1/wD2=(D1/D2)^{0.23}.

  10. Space Weather and Management of Environmental Risks and Hazards

    NASA Astrophysics Data System (ADS)

    Pirjola, R.; Kauristie, K.; Lappalainen, H.

    "Space Weather" is defined as electromagnetic and particle conditions in the space environment that can disturb space-borne and ground-based technological systems (e.g. satellite operation, telecommunication, aviation, electric power transmission) and even endanger human health. Thus, space weather is of great importance to the society since people are dependent on reliable operation of modern technology, interruptions of which may lead to large economical and other losses. Physical processes involved in space weather constitute a complicated chain from the Sun to the Earth's surface. Thus, a full understanding of space weather and the risks it produces requires expertise in many different disciplines of science and technology. Space weather is a new subject among the natural risks and hazards which threaten the society and its infrastructure (although the first observations of ground effects of space weather were already made about 150 years ago). Monitoring systems for the management of other risks, such as floods, forest fires, etc., and for security are, to a great extent, based on satellite observations. Spacecraft and the communication between satellites and the ground are vulnerable to space weather. Thus, besides being a direct risk to technological systems, space weather may also be indirectly adverse to risk management. These two aspects of space weather are considered in a proposal to be submitted to EU's Sixth Framework Programme under the "Aeronautics and Space" priority in the "Global Monitoring for Environment and Security (GMES) / Risk Management" area in March 2004. The proposal coordinated by the Finnish Meteorological Institute with five to ten participating institutes is called SW-RISK ("Space Weather - Risk Indices from Scientific Know-how").

  11. Long-term snow and weather observations at Weissfluhjoch and its relation to other high-altitude observatories in the Alps

    NASA Astrophysics Data System (ADS)

    Marty, Christoph; Meister, Roland

    2012-12-01

    Snow and weather observations at Weissfluhjoch were initiated in 1936, when a research team set a snow stake and started digging snow pits on a plateau located at 2,540 m asl above Davos, Switzerland. This was the beginning of what is now the longest series of daily snow depth, new snow height and bi-monthly snow water equivalent measurements from a high-altitude research station. Our investigations reveal that the snow depth at Weissfluhjoch with regard to the evolution and inter-annual variability represents a good proxy for the entire Swiss Alps. In order to set the snow and weather observations from Weissfluhjoch in a broader context, this paper also shows some comparisons with measurements from five other high-altitude observatories in the European Alps. The results show a surprisingly uniform warming of 0.8°C during the last three decades at the six investigated mountain stations. The long-term snow measurements reveal no change in mid-winter, but decreasing trends (especially since the 1980s) for the solid precipitation ratio, snow fall, snow water equivalent and snow depth during the melt season due to a strong temperature increase of 2.5°C in the spring and summer months of the last three decades.

  12. Weather Tools

    NSDL National Science Digital Library

    The Miami Museum of Science provides a variety of activities to help students learn about the many weather instruments including wind scales and wind chimes. Students can learn about the wind, air pressure, moisture, and temperature.

  13. THE WEATHER AND CLIMATE TOOLKIT

    Microsoft Academic Search

    Steve Ansari; Chad Hutchins; Stephen Del Greco; Mark Phillips

    The Weather and Climate Toolkit (WCT) is free, platform independent software distributed from NOAA's National Climatic Data Center (NCDC). The WCT allows the visualization and data export of weather and climate data, including NEXRAD Radar, GOES Satellite, NOMADS Model and surface in-situ data. By leveraging the NetCDF for Java library and Common Data Model, the WCT is extremely scalable and

  14. Gravestone Weathering

    NSDL National Science Digital Library

    Leanne Wiberg

    2000-01-01

    In this activity (located on pages 9-14 of PDF), learners visit a cemetery to examine the distinguishing characteristics of rock weathering. After researching stone weathering and acid rain, learners apply their knowledge to collect data related to chemical decomposition and physical disintegration at a cemetery site. This detailed lesson guide includes tips for educators, pre/post activity suggestions, hands-outs, and background information.

  15. Weather Creator

    NSDL National Science Digital Library

    KShumway

    2009-09-28

    This project explores factors that help create severe winter weather. An interactive simulation provides hands-on experience, followed by guiding questions and resource exploration. Form groups of three. Explore the following simulation: Weather Maker Simulator Use the simulation to answer the following questions on paper. 1. In general, when are winds formed? 2. When winds are blowing, how can you get them to stop? 3. What can you do to make it rain or even snow? 4. Does it always snow when ...

  16. Upgrade Summer Severe Weather Tool in MIDDS

    NASA Technical Reports Server (NTRS)

    Wheeler, Mark M.

    2010-01-01

    The goal of this task was to upgrade the severe weather database from the previous phase by adding weather observations from the years 2004 - 2009, re-analyze the data to determine the important parameters, make adjustments to the index weights depending on the analysis results, and update the MIDDS GUI. The added data increased the period of record from 15 to 21 years. Data sources included local forecast rules, archived sounding data, surface and upper air maps, and two severe weather event databases covering east-central Florida. Four of the stability indices showed increased severe weather predication. The Total Threat Score (TTS) of the previous work was verified for the warm season of 2009 with very good skill. The TTS Probability of Detection (POD) was 88% and the False alarm rate (FAR) of 8%. Based on the results of the analyses, the MIDDS Severe Weather Worksheet GUI was updated to assist the duty forecaster by providing a level of objective guidance based on the analysis of the stability parameters and synoptic-scale dynamics.

  17. Weather Specialist (AFSC 25120).

    ERIC Educational Resources Information Center

    Air Univ., Gunter AFS, Ala. Extension Course Inst.

    This correspondence course is designed for self-study to help military personnel to attain the rating of weather specialist. The course is organized in three volumes. The first volume, containing seven chapters, covers background knowledge, meteorology, and climatology. In the second volume, which also contains seven chapters, surface

  18. Severe Weather Forecast Decision Aid

    NASA Technical Reports Server (NTRS)

    Bauman, William H., III; Wheeler, Mark M.; Short, David A.

    2005-01-01

    This report presents a 15-year climatological study of severe weather events and related severe weather atmospheric parameters. Data sources included local forecast rules, archived sounding data, Cloud-to-Ground Lightning Surveillance System (CGLSS) data, surface and upper air maps, and two severe weather event databases covering east-central Florida. The local forecast rules were used to set threat assessment thresholds for stability parameters that were derived from the sounding data. The severe weather events databases were used to identify days with reported severe weather and the CGLSS data was used to differentiate between lightning and non-lightning days. These data sets provided the foundation for analyzing the stability parameters and synoptic patterns that were used to develop an objective tool to aid in forecasting severe weather events. The period of record for the analysis was May - September, 1989 - 2003. The results indicate that there are certain synoptic patterns more prevalent on days with severe weather and some of the stability parameters are better predictors of severe weather days based on locally tuned threat values. The results also revealed the stability parameters that did not display any skill related to severe weather days. An interactive web-based Severe Weather Decision Aid was developed to assist the duty forecaster by providing a level of objective guidance based on the analysis of the stability parameters, CGLSS data, and synoptic-scale dynamics. The tool will be tested and evaluated during the 2005 warm season.

  19. Weathering and weathering rates of natural stone

    NASA Astrophysics Data System (ADS)

    Winkler, Erhard M.

    1987-06-01

    Physical and chemical weathering were studied as separate processes in the past. Recent research, however, shows that most processes are physicochemical in nature. The rates at which calcite and silica weather by dissolution are dependent on the regional and local climatic environment. The weathering of silicate rocks leaves discolored margins and rinds, a function of the rocks' permeability and of the climatic parameters. Salt action, the greatest disruptive factor, is complex and not yet fully understood in all its phases, but some of the causes of disruption are crystallization pressure, hydration pressure, and hygroscopic attraction of excess moisture. The decay of marble is complex, an interaction between disolution, crack-corrosion, and expansion-contraction cycies triggered by the release of residual stresses. Thin spalls of granites commonly found near the street level of buildings are generally caused by a combination of stress relief and salt action. To study and determine weathering rates of a variety of commercial stones, the National Bureau of Standards erected a Stone Exposure Test Wall in 1948. Of the many types of stone represented, only a few fossiliferous limestones permit a valid measurement of surface reduction in a polluted urban environment.

  20. Surface topography estimated by inversion of satellite gravity gradiometry observations

    NASA Astrophysics Data System (ADS)

    Ramillien, Guillaume

    2015-04-01

    An integration of mass elements is presented for evaluating the six components of the 2-order gravity tensor (i.e., second derivatives of the Newtonian mass integral for the gravitational potential) created by an uneven sphere topography consisting of juxtaposed vertical prisms. The method is based on Legendre polynomial series with the originality of taking elastic compensation of the topography by the Earth's surface into account. The speed of computation of the polynomial series increases logically with the observing altitude from the source of anomaly. Such a forward modelling can be easily used for reduction of observed gravity gradient anomalies by the effects of any spherical interface of density. Moreover, an iterative least-square inversion of the observed gravity tensor values ??? is proposed to estimate a regional set of topographic heights. Several tests of recovery have been made by considering simulated gradiometry anomaly data, and for varying satellite altitudes and a priori levels of accuracy. In the case of GOCE-type gradiometry anomalies measured at an altitude of ~300 km, the search converges down to a stable and smooth topography after 20-30 iterations while the final r.m.s. error is ~100 m. The possibility of cumulating satellite information from different orbit geometries is also examined for improving the prediction.

  1. Inter-annual variation of the surface temperature of tropical forests from SSM/I observations

    NASA Astrophysics Data System (ADS)

    Gao, H.; Fu, R.; Li, W.; Zhang, S.; Dickinson, R. E.

    2014-12-01

    Land surface temperatures (LST) within tropical rain forests contribute to climate variation, but observational data are very limited in these regions. In this study, all weather canopy sky temperatures were retrieved using the passive microwave remote sensing data from the Special Sensor Microwave/Imager (SSM/I) and the Special Sensor Microwave Imager/Sounder (SSMIS) over the Amazon and Congo rainforests. The remote sensing data used were collected from 1996 to 2012 using two separate satellites—F13 (1996-2009) and F17 (2007-2012). An inter-sensor calibration between the brightness temperatures collected by the two satellites was conducted in order to ensure consistency amongst the instruments. The interannual changes of LST associated with the dry and wet anomalies were investigated in both regions. The dominant spatial and temporal patterns for inter-seasonal variations of the LST over the tropical rainforest were analyzed, and the impacts of droughts and El Niños (on LST) were also investigated. The remote sensing results suggest that the morning LST is mainly controlled by atmospheric humidity (which controls longwave radiation) whereas the late afternoon LST is controlled by solar radiation.

  2. A climatology of dust emission events from northern Africa using long-term surface observations

    NASA Astrophysics Data System (ADS)

    Cowie, S. M.; Knippertz, P.; Marsham, J. H.

    2014-03-01

    Long-term (1984-2012) surface observations from 70 stations in the Sahara and Sahel are used to explore the diurnal, seasonal and geographical variations in dust emission events and thresholds. The frequency of dust emission (FDE) is calculated using the present weather codes of SYNOP reports. Thresholds are estimated as the wind speed for which there is a 50% probability of dust emission and are then used to calculate strong wind frequency (SWF) and dust uplift potential (DUP), where the latter is an estimate of the dust-generating power of winds. Stations are grouped into six coherent geographical areas for more in-depth analysis. FDE is highest at stations in Sudan and overall peaks in spring north of 23° N. South of this, where stations are directly influenced by the summer monsoon, the annual cycle in FDE is more variable. Thresholds are highest in northern Algeria, lowest in the latitude band 16-21° N and have greatest seasonal variations in the Sahel. Spatial variability in thresholds partly explain spatial variability in frequency of dust emission events on an annual basis. However, seasonal variations in thresholds for the six grouped areas are not the main control on seasonal variations in FDE. This is demonstrated by highly correlated seasonal cycles of FDE and SWF which are not significantly changed by using a fixed, or seasonally varying, threshold. The likely meteorological mechanisms generating these patterns such as low-level jets and haboobs are discussed.

  3. A climatology of dust emission events from northern Africa using long-term surface observations

    NASA Astrophysics Data System (ADS)

    Cowie, S. M.; Knippertz, P.; Marsham, J. H.

    2014-08-01

    Long-term (1984-2012) surface observations from 70 stations in the Sahara and Sahel are used to explore the diurnal, seasonal and geographical variations in dust emission events and thresholds. The frequency of dust emission (FDE) is calculated using the present weather codes of SYNOP reports. Thresholds are estimated as the wind speed for which there is a 50% probability of dust emission and are then used to calculate strong wind frequency (SWF) and dust uplift potential (DUP), where the latter is an estimate of the dust-generating power of winds. Stations are grouped into six coherent geographical areas for more in-depth analysis. FDE is highest at stations in Sudan and overall peaks in spring north of 23° N. South of this, where stations are directly influenced by the summer monsoon, the annual cycle in FDE is more variable. Thresholds are highest in northern Algeria, lowest in the latitude band 16-21° N and have greatest seasonal variations in the Sahel. Spatial variability in thresholds partly explain spatial variability in frequency of dust emission events on an annual basis. However, seasonal variations in thresholds for the six grouped areas are not the main control on seasonal variations in FDE. This is demonstrated by highly correlated seasonal cycles of FDE and SWF which are not significantly changed by using a fixed, or seasonally varying, threshold. The likely meteorological mechanisms generating these patterns such as low-level jets and haboobs are discussed.

  4. Observation and modeling of surface ozone over Greenland

    SciTech Connect

    Kiilsholm, I.S.; Mikkelsen, I.S.; Rasmussen, A.; Sorensen, J.H. [Danish Meteorological Institute, Copenhagen (Denmark)

    1996-12-31

    DMI initiated continuous measurements of surface ozone concentration in Greenland during spring 1994 as apart of the ARCTOC project (ARCtic Tropospheric Ozone Chemistry). The ARCTOC project is partially financed by EU, and is coordinated by the Institute for Environmental Physics, University of Heidelberg. The objectives are to investigate the mechanism causing sudden arctic tropospheric ozone loss, spatial extent and possible consequences of the phenomenon. The observation sites in Greenland are Thule (76{degrees} 31{prime} N, 68{degrees} 50{prime} W), Sondre Stromfjord (67{degrees} 00{prime} N, 50{degrees} 48{prime}W) and Scoresbysund (70{degrees} 29{prime}N, 21{degrees} 58{prime} W). The instruments are photometric ozone analyzers. Preliminary results show that the air parcels with low ozone values have spent four days or more in the boundary layer and have recently passed the strait between Canada and Greenland.

  5. An OSSE on Mesoscale Model Assimilation of Simulated HIRAD-Observed Hurricane Surface Winds

    NASA Technical Reports Server (NTRS)

    Albers, Cerese; Miller, Timothy; Uhlhorn, Eric; Krishnamurti, T. N.

    2012-01-01

    The hazards of landfalling hurricanes are well known, but progress on improving the intensity forecasts of these deadly storms at landfall has been slow. Many cite a lack of high-resolution data sets taken inside the core of a hurricane, and the lack of reliable measurements in extreme conditions near the surface of hurricanes, as possible reasons why even the most state-of-the-art forecasting models cannot seem to forecast intensity changes better. The Hurricane Imaging Radiometer (HIRAD) is a new airborne microwave remote sensor for observing hurricanes, and is operated and researched by NASA Marshall Space Flight Center in partnership with the NOAA Atlantic Oceanographic and Meteorological Laboratory/Hurricane Research Division, the University of Central Florida, the University of Michigan, and the University of Alabama in Huntsville. This instrument?s purpose is to study the wind field of a hurricane, specifically observing surface wind speeds and rain rates, in what has traditionally been the most difficult areas for other instruments to study; the high wind and heavy rain regions. Dr. T. N. Krishnamurti has studied various data assimilation techniques for hurricane and monsoon rain rates, and this study builds off of results obtained from utilizing his style of physical initializations of rainfall observations, but obtaining reliable observations in heavy rain regions has always presented trouble to our research of high-resolution rainfall forecasting. Reliable data from these regions at such a high resolution and wide swath as HIRAD provides is potentially very valuable to mesoscale forecasting of hurricane intensity. This study shows how the data assimilation technique of Ensemble Kalman Filtering (EnKF) in the Weather Research and Forecasting (WRF) model can be used to incorporate wind, and later rain rate, data into a mesoscale model forecast of hurricane intensity. The study makes use of an Observing System Simulation Experiment (OSSE) with a simulated HIRAD dataset sampled during a hurricane and uses EnKF to forecast the track and intensity prediction of the hurricane. Comparisons to truth and error metrics are used to assess the model?s forecast performance.

  6. Object Dependent Properties of Mirrors for PV Applications Studied Under Accelerated Weathering Protocols

    E-print Network

    Rollins, Andrew M.

    mirrors the two main concerns for degradation are surface roughness and corrosion. Surface roughening can over the past two years to explore exposure protocols for accelerated weathering of back-surface to corrosive environments, a variety of degradation modes have been observed. In order to characterize changes

  7. Observations of Lightning on Earth from the Lunar Surface

    NASA Technical Reports Server (NTRS)

    Goodman, S. J.; Buechler, D. E.; Christian, H. J., Jr.; Stahl, H. P.

    2007-01-01

    The NASA Optical Transient Detector (OTD) launched into a 70deg inclination orbit in April 1995 aboard the MicroLab-1 satellite and the Lightning Imaging Sensor (LIS) launched into a 35deg inclination orbit in November 1997 (and still operating today) aboard the Tropical Rainfall Measuring Mission have produced the most comprehensive global observations of lightning activity on Earth. The OTD collected data for 5-yr from an altitude of 740 km while the LIS, in its 10th year of operations, is still collecting data from its current altitude of 402 km. From these altitudes the OTD observes an individual storm within its field of view for approx.3 min and the LIS for approx.90 sec as the satellites orbit the earth. Figures 1-4 show the combined LIS/OTD distribution of lightning for day and night during the Northern Hemisphere warm season from April through August (Fig. 1,2) and the cool season from October through February (Fig. 3,4) as might be observed from the lunar surface (12-h daylight and 12-h nighttime observations). The day and night plots are for the twelve hour periods centered on local noon and midnight. The total viewtime of the global lightning activity is 200 hours or less, depending on latitude (Fig. 5). Most of the observed lightning occurs over the northern hemisphere land areas as reported in previous studies. More lightning activity is seen at the higher northern latitudes during the day. The greatest lightning maxima occurs in the southeastern US, during the day. The corresponding region at night shows much less lightning activity. In contrast, there is a maxima in lightning activity at night over the high Plains area of the U.S. This region had lower lightning rates during the daytime period. During the cold season, the southern hemisphere has significantly more lightning. The maxima in Central Africa is still present, and a secondary maxima is observed in South Africa. In South America, the maxima in Argentina occurs at night in association with large-scale mesoscale convective storm complexes. This is the region on the earth having the greatest frequency of extreme storms with flash rates exceeding 1000 flashes/min. daytime maxima is seen extending from Northern Argentina to Brazil. In the US., the Gulf of Mexico and the Gulf Coast states exhibit a maximum in lightning activity both day and night.

  8. Gemini near-infrared observations of Europa's Hydrated Surface Materials

    NASA Astrophysics Data System (ADS)

    Tsang, C.; Spencer, J. R.; Grundy, W. M.; Dalton, J. B.

    2012-12-01

    Europa is a highly dynamic icy moon of Jupiter. It is thought the moon harbors a subsurface ocean, with the potential to sustain life, with Europa being a key target of ESA's forthcoming Jupiter Icy Moons Orbiter (JUICE) mission. However, much is not known concerning the chemistry of the subsurface ocean. The surface is dominated by water ice, with a hydrated non-ice material component providing the distinctive albedo contrasts seen at visible and near-infrared wavelengths. These non-ice materials are concentrated at disrupted surface regions, providing a diagnostic probe for the chemistry and characteristics of the liquid ocean beneath. Leading but potentially competing theories on the composition of these hydrated non-ice materials suggest either sulfuric acid-water mixtures (Carlson et al., 1999) or hydrated magnesium/sodium salts (McCord et al., 1999). Recent reanalysis of Galileo-NIMS observations suggest a mixture of both - hydrated salts are present at all longitudes but the sulfuric acid hydrates are localized on the trailing side. We present preliminary analysis of new ground-based Gemini disk-resolved spectroscopy of Europa using the Near-Infrared Integrated Field Spectrometer (NIFS), taken in late 2011, at H (1.49 - 1.80 ?m) and K bands (1.99 - 2.40 ?m) with spectral resolving powers of ~ 5300. At these NIR wavelengths, with spectral resolution much better than Galileo-NIMS, the spectral absorption and continuum characteristics of these ice and non-ice materials can be separated out. In addition, the spatial resolution potentially allows identification of localized materials whose signature would be diluted in disk-integrated spectra. These observations of the trailing hemisphere use Altair adaptive optics to achieve spatial resolutions of 0.1" (~310 km per pixel) or better, potentially leading to better identification of the non-ice materials and their spatial distributions. References Carlson, R.W., R.E. Johnson, and M.S. Anderson 1999. Sulfuric acid on Europa and the radiolytic sulfur cycle. Science 286, 97-99. McCord, T. et al. 1999. Hydrated salt minerals on Europa's surface from the Galileo Near- Infrared Mapping Spectrometer (NIMS) investigation. J. Geophys. Res. 104, 11827

  9. Surface Climate and Snow?Weather Relationships of the Kuparuk Basin onAlaska’s Arctic Slope

    Microsoft Academic Search

    Glen E. Liston; Douglas L. Kane; Usarmy Corps

    Abstract: This report summarizes temperature, wind, and snow-cover data for the Kuparuk River Basin in Arctic Alaska spanning,the five-year peri- od of 1994–1998. Comparison,of results from five meteorological,towers,is presented,to illustrate both the differences and similarities of the region- alclimate and weather,along a 200-km transect. A picture emerges,of the,Arctic Slope as a,region dominated,by subfreezing,temperatures,for most of the annual cycle. The five

  10. A SYSTEM FOR REALISTIC WEATHER RENDERING

    Microsoft Academic Search

    Kirk Riley; Charles Hansen; Jason Levit

    Weather visualization has traditionally been restricted to surface models and 2-D representations. We present a visually accurate method for rendering volumetric multi-field weather data that includes cloud water, ice, rain, snow, and graupel hydrometeors. This representation better communicates the complex 3-D nature of weather, by rendering it according to physically based lighting and scattering characteristics of hydrometeor particles. The rendering

  11. Quantification of physical weathering rates using thermodynamics

    Microsoft Academic Search

    F. Gans; S. Arens; S. J. Schymanski; A. Kleidon

    2010-01-01

    Physical weathering plays an important role in the global rock cycle in that it breaks up primary rock, thereby increasing the surface area for chemical weathering and providing the substrate for soil formation. We use a simple, thermodynamics based approach to quantify magnitudes of weathering, their spatial variation across climatic regions and their sensitivity to climatic change. Our approach is

  12. Compressive Strength of Cometary Surfaces Derived from Radar Observations

    NASA Astrophysics Data System (ADS)

    ElShafie, A.; Heggy, E.

    2014-12-01

    Landing on a comet nucleus and probing it, mechanically using harpoons, penetrometers and drills, and electromagnetically using low frequency radar waves is a complex task that will be tackled by the Rosetta mission for Comet 67P/Churyumov-Gerasimenko. The mechanical properties (i.e. density, porosity and compressive strength) and the electrical properties (i.e. the real and imaginary parts of the dielectric constant) of the comet nucleus, constrain both the mechanical and electromagnetic probing capabilities of Rosetta, as well as the choice of landing site, the safety of the landing, and subsurface data interpretation. During landing, the sounding radar data that will be collected by Rosetta's CONSERT experiment can be used to probe the comet's upper regolith layer by assessing its dielectric properties, which are then inverted to retrieve the surface mechanical properties. These observations can help characterize the mechanical properties of the landing site, which will optimize the operation of the anchor system. In this effort, we correlate the mechanical and electrical properties of cometary analogs to each other, and derive an empirical model that can be used to retrieve density, porosity and compressive strength from the dielectric properties of the upper regolith inverted from CONSERT observations during the landing phase. In our approach we consider snow as a viable cometary material analog due to its low density and its porous nature. Therefore, we used the compressive strength and dielectric constant measurements conducted on snow at a temperature of 250 K and a density range of 0.4-0.9 g/cm3 in order to investigate the relation between compressive strength and dielectric constant under cometary-relevant density range. Our results suggest that compressive strength increases linearly as function of the dielectric constant over the observed density range mentioned above. The minimum and maximum compressive strength of 0.5 and 4.5 MPa corresponded to a dielectric constant of 2.2 and 3.4 over the density range of 0.4-0.9 g/cm3. This preliminary correlation will be applied to the case of porous and dust contaminated snow under different temperatures to assess the surface mechanical properties for Comet 67P.

  13. Titan's Methane Weather

    NASA Astrophysics Data System (ADS)

    Roe, Henry G.

    2012-05-01

    Conditions in Titan's troposphere are near the triple point of methane, the second most abundant component of its atmosphere. Our understanding of Titan's lower atmosphere has shifted considerably in the past decade. Ground-based observations, Hubble Space Telescope images, and data returned from the Cassini and Huygens spacecraft show that Titan's troposphere hosts a methane-based meteorology in direct analogy to the water-based meteorology of Earth. What once was thought to be a quiescent place, lacking in clouds or localized weather and changing only subtly on long seasonal timescales, is now understood to be a dynamic system with significant weather events regularly occurring against the backdrop of dramatic seasonal changes. Although the observational record of Titan's weather covers only a third of its 30-year seasonal cycle, Titan's atmospheric processes appear to be more closely analogous to those of Earth than to those of any other object in our solar system.

  14. The Weather Doctor

    NSDL National Science Digital Library

    Heidorn, Keith C.

    Published by Spectrum Educational Enterprises, The Weather Doctor Web site is maintained by meteorologist Keith Heidorn. Visitors to the site will find everything from the joys of weather watching, to making rain, to weather history, to much more. Coming from someone who clearly enjoys what they do, this site explores unique aspects of weather including weather people, weather history, and weather and arts.

  15. Spaceborne weather radar

    NASA Technical Reports Server (NTRS)

    Meneghini, Robert; Kozu, Toshiaki

    1990-01-01

    The present work on the development status of spaceborne weather radar systems and services discusses radar instrument complementarities, the current forms of equations for the characterization of such aspects of weather radar performance as surface and mirror-image returns, polarimetry, and Doppler considerations, and such essential factors in spaceborne weather radar design as frequency selection, scanning modes, and the application of SAR to rain detection. Attention is then given to radar signal absorption by the various atmospheric gases, rain drop size distribution and wind velocity determinations, and the characteristics of clouds, as well as the range of available estimation methods for backscattering, single- and dual-wavelength attenuation, and polarimetric and climatological characteristics.

  16. Analysis of natural IR background signatures with respect to statistical relationships between background surface temperatures and weather parameters

    NASA Astrophysics Data System (ADS)

    Theunert, Friedrich

    1994-06-01

    A program system for displaying and analyzing IR-background-images is presented. This system allows analysis of image data -- statistical and textural parameters of the entire scenery or of a predefined image section -- for a specified scenery image series. Subsequently, statistical relationships like correlations between image parameters on the one hand, and meteorological parameters as well as time of day and season on the other hand, are evaluated. Results will predominantly be used for the development and validation of tactical decision aids for IR-range forecasts. In addition, evaluations might be of interest for performance assessment of camouflage and EO-systems efficiency. Actually, the program system is being applied to the evaluation of two data sets, each of them comprising measurements (infra-red images with synchronous weather data) over one year. One data set was obtained in norther Germany, the other one in southern Germany. The data base contains a total of about 12,000 IR-images, for a variety of specified sceneries, seasons, and weather situations. Some preliminary results are shown and discussed.

  17. Wild Weather

    NSDL National Science Digital Library

    2012-08-03

    In this online, interactive module, students learn about severe weather (thunderstorms, hurricanes, tornadoes, and blizzards) and the key features for each type of "wild weather" using satellite images. The module is part of an online course for grades 7-12 in satellite meteorology, which includes 10 interactive modules. The site also includes lesson plans developed by teachers and links to related resources. Each module is designed to serve as a stand-alone lesson, however, a sequential approach is recommended. Designed to challenge students through the end of 12th grade, middle school teachers and students may choose to skim or skip a few sections.

  18. Weather Forecasting

    NSDL National Science Digital Library

    In this online, interactive module, students will learn how to interpret weather patterns from satellite images, predict storm paths and forecast the weather for their area. The module is part of an online course for grades 7-12 in satellite meteorology, which includes 10 interactive modules. The site also includes lesson plans developed by teachers and links to related resources. Each module is designed to serve as a stand-alone lesson, however, a sequential approach is recommended. Designed to challenge students through the end of 12th grade, middle school teachers and students may choose to skim or skip a few sections.

  19. Weather One

    NSDL National Science Digital Library

    1969-12-31

    From the University of Illinois Extension comes the Weather One instructional Web site for kids. The lesson consists of six pages that cover various weather related topics including seasons, clouds, the atmosphere, wind, global warming, and storms. Each page describes the particular subject, provides related photographs, and contains several activities that reinforce the learning. For example, the clouds page shows how kids can make a cloud and create a collage out of simple material found around the house. The effective organization and clean look of the site will surely make it easy for students to follow and enjoy.

  20. Synergy of Satellite-Surface Observations for Studying the Properties of Absorbing Aerosols in Asia

    NASA Technical Reports Server (NTRS)

    Tsay, Si-Chee

    2010-01-01

    Through interaction with clouds and alteration of the Earth's radiation budget, atmospheric aerosols significantly influence our weather and climate. Monsoon rainfalls, for example, sustain the livelihood of more than half of the world's population. Thus, understanding the mechanism that drives the water cycle and freshwater distribution is high-lighted as one of the major near-term goals in NASA's Earth Science Enterprise Strategy. Every cloud droplet/ice-crystal that serves as an essential element in portraying water cycle and distributing freshwater contains atmospheric aerosols at its core. In addition, the spatial and temporal variability of atmospheric aerosol properties is complex due to their dynamic nature. In fact, the predictability of the tropical climate system is much reduced during the boreal spring, which is associated with the peak season of biomass burning activities and regional/long-range transport of dust aerosols. Therefore, to accurately assess the impact of absorbing aerosols on regional-to-global climate requires not only modeling efforts but also continuous observations from satellites, aircraft, networks of ground-based instruments and dedicated field experiments. Since 1997 NASA has been successfully launching a series of satellites the Earth Observing System - to intensively study, and gain a better understanding of, the Earth as an integrated system. Through participation in many satellite remote-sensing/retrieval and validation projects over the years, we have gradually developed and refined the SMART (Surface-sensing Measurements for Atmospheric Radiative Transfer) and COMMIT (Chemical, Optical & Microphysical Measurements of In-situ Troposphere) mobile observatories, a suite of surface remote sensing and in-situ instruments that proved to be vital in providing high temporal measurements, which complement the satellite observations. In this talk, we will present SMART-COMMIT which has played key roles, serving as network or supersite, in major international research projects such as the Joint Aerosol Monsoon Experiment (JAM EX), a core element of the Asian Monsoon Years (AMY, 2008-2012). SMART-COMMIT deployments during 2008 AMY/JAMEX were conducted in northwestern China to characterize the properties of dust-laden aerosols and in the vicinity of Beijing for mega-city aerosols. In 2009, SMART-COMMIT also participated in the JAMEX/RAJO-MEGHA (Radiation, Aerosol Joint Observations-Monsoon Experiment in the Gangetic-Himalayan Area; Sanskrit for Dust-Cloud) to study the aerosol properties, solar absorption and the associated atmospheric warming, and the climatic impact of elevated aerosols during the pre-monsoon season in South Asia. We will show results from these field experiments, as well as discuss a new initiative of 7-SEAS (7 South East Asian Studies) to study the interaction of anthropogenic aerosols with regional meteorology, particularly with clouds.

  1. Observational effects of magnetism in O stars: surface nitrogen abundances

    NASA Astrophysics Data System (ADS)

    Martins, F.; Escolano, C.; Wade, G. A.; Donati, J. F.; Bouret, J. C.; Mimes Collaboration

    2012-02-01

    Aims: We investigate the surface nitrogen content of the six magnetic O stars known to date as well as of the early B-type star ? Sco. We compare these abundances to predictions of evolutionary models to isolate the effects of magnetic field on the transport of elements in stellar interiors. Methods: We conduct a quantitative spectroscopic analysis of the sample stars with state-of-the-art atmosphere models. We rely on high signal-to-noise ratio, high resolution optical spectra obtained with ESPADONS at CFHT and NARVAL at TBL. Atmosphere models and synthetic spectra are computed with the code CMFGEN. Values of N/H together with their uncertainties are determined and compared to predictions of evolutionary models. Results: We find that the magnetic stars can be divided into two groups: one with stars displaying no N enrichment (one object); and one with stars most likely showing extra N enrichment (5 objects). For one star (?1 Ori C) no robust conclusion can be drawn due to its young age. The star with no N enrichment is the one with the weakest magnetic field, possibly of dynamo origin. It might be a star having experienced strong magnetic braking under the condition of solid body rotation, but its rotational velocity is still relatively large. The five stars with high N content were probably slow rotators on the zero age main sequence, but they have surface N/H typical of normal O stars, indicating that the presence of a (probably fossil) magnetic field leads to extra enrichment. These stars may have a strong differential rotation inducing shear mixing. Our results should be viewed as a basis on which new theoretical simulations can rely to better understand the effect of magnetism on the evolution of massive stars. Based on observations collected at the CFHT and the Télescope Bernard Lyot.Appendix A is available in electronic form at http://www.aanda.org

  2. A machine learning based approach to weather parameter estimation in Doppler weather radar

    Microsoft Academic Search

    Satoshi Kon; Toshihisa Tanaka; Humihiko Mizutani; Masakazu Wada

    2011-01-01

    An observed signal of the Doppler weather radar includes not only weather echoes but also a ground clutter. For accurate observation of weather data, we need to remove the effect of the ground clutter. In this paper, we propose to model the spectrum of an observed IQ signal as a mixture density function. To estimate the parameters of the density

  3. Observations During GRIP from HIRAD: Images of C-Band Brightness Temperatures and Ocean Surface Wind Speed and Rain Rate

    NASA Technical Reports Server (NTRS)

    Miller, Timothy L.; James, M. W.; Jones, W. L.; Ruf, C. S.; Uhlhorn, E. W.; Biswas, S.; May, C.; Shah, G.; Black, P.; Buckley, C. D.

    2012-01-01

    HIRAD (Hurricane Imaging Radiometer) flew on the WB-57 during NASA s GRIP (Genesis and Rapid Intensification Processes) campaign in August - September of 2010. HIRAD is a new C-band radiometer using a synthetic thinned array radiometer (STAR) technology to obtain cross-track resolution of approximately 3 degrees, out to approximately 60 degrees to each side of nadir. By obtaining measurements of emissions at 4, 5, 6, and 6.6 GHz, observations of ocean surface wind speed and rain rate can be inferred. This technique has been used for many years by precursor instruments, including the Stepped Frequency Microwave Radiometer (SFMR), which has been flying on the NOAA and USAF hurricane reconnaissance aircraft for several years. The advantage of HIRAD over SFMR is that HIRAD can observe a +/- 60-degree swath, rather than a single footprint at nadir angle. Results from the flights during the GRIP campaign will be shown, including images of brightness temperatures, wind speed, and rain rate. To the extent possible, comparisons will be made with observations from other instruments on the GRIP campaign, for which HIRAD observations are either directly comparable or are complementary. Features such as storm eye and eyewall, location of vortex wind and rain maxima, and indications of dynamical features such as the merging of a weaker outer wind/rain maximum with the main vortex may be seen in the data. Potential impacts on operational ocean surface wind analyses and on numerical weather forecasts will also be discussed.

  4. Great Lakes Weather and Climate Location, Dimensions and Configuration

    NSDL National Science Digital Library

    This self-paced, interactive tutorial explores the use of remote-sensing data to monitor Great Lakes weather and climate. Interactive tools are provided to allow the learner to compare the surface area of the different Great Lakes. Seasonal climate extremes observed in the Great Lakes region is explained by the geographical characteristics of its mid-latitudinal location, and are documented in a series of seasonal images produced by satellite sensors. This resource is part of the tutorial series, Satellite Observations in Science Education, and is the first of three modules in the tutorial, Great Lakes Weather and Climate. (Note: requires Java plug-in)

  5. Cold Weather I usually start my climate presentations with a chart showing maps of the surface temperature

    E-print Network

    Hansen, James E.

    . Figure 1. Global distributions of surface temperature anomalies of the last four months (GISS analysis-global temperature, as well as the trend over recent decades can be seen in Figure 2 for the GISS surface temperature, close to the surface temperature trend (0.17°C per decade). The large short-term temperature

  6. Comparing variability and trends in observed and modelled globalmean surface temperature

    E-print Network

    land surface temperature and sea surface temperature (SST) datasets [Brohan et al., 2006Comparing variability and trends in observed and modelled globalmean surface temperature John C; accepted 6 July 2010; published 19 August 2010. [1] The observed evolution of the globalmean surface

  7. Large-scale dynamic observation planning for unmanned surface vessels

    E-print Network

    Miller, John V. (John Vaala)

    2007-01-01

    With recent advances in research and technology, autonomous surface vessel capabilities have steadily increased. These autonomous surface vessel technologies enable missions and tasks to be performed without the direction ...

  8. Today's Weather

    NSDL National Science Digital Library

    This activity is part of Planet Diary and contains an online exploration of weather maps. Students use current maps to learn about and locate different features such as low-pressure areas and fronts. They then explore how these are related to severe storms.

  9. Weather Stations

    NSDL National Science Digital Library

    This is a series of seven brief activities about Jupiter's atmosphere and weather. Learners will look at Jupiter's distinct banded appearance, violent storms, and clouds of many different colors. The activities are part of Explore! Jupiter's Family Secrets, a series designed to engage children in space and planetary science in libraries and informal learning environments.

  10. Weather Alert

    NSDL National Science Digital Library

    Integrated Teaching and Learning Program,

    Students discuss the characteristics of storms, including the relationship of weather fronts and storms. Using everyday materials, they develop models of basic lightning detection systems (similar to a Benjamin Franklin design) and analyze their models to determine their effectiveness as community storm warning systems.

  11. METEOROLOGICAL Monthly Weather Review

    E-print Network

    Rutledge, Steven

    Science, Colorado State University, Fort Collins, Colorado Submitted to Monthly Weather Review 9 September 2010 Corresponding Author Address: Angela K. Rowe Department of Atmospheric Science Colorado State subsequent freezing to produce graupel. Similar features were also observed in an isolated cell over

  12. Weather and the Sky

    NSDL National Science Digital Library

    Houghton Mifflin Science

    This self-contained module on weather and objects in the sky includes a range of fun activities that students can perform in the classroom and at home with family members. They impart important concepts such as observation, identification, measurement, and differentiation.

  13. Kid Meteorologist - I Love the Weather!

    NSDL National Science Digital Library

    2005-10-21

    What would we do without meteorologists? Weather forecasts enable you to plan everything from what you'll wear to whether weekend activities should be indoors or outdoors. They also help us prepare for bad weather and storms. In this video from the PBS television show ZOOM, a student (Amy from Walpole, MA) describes how her interest in observing the weather led her to volunteer at a local weather center where she uses real weather instruments and learns from a practicing meteorologist how weather forecasts are made.

  14. Comparison of AIRS and IASI Surface Observations of DomeC in Antarctica with Surface Temperatures Reported by AWS8989

    NASA Astrophysics Data System (ADS)

    Elliott, D. A.; Aumann, H. H.

    2008-12-01

    The decrease of the ice in the Antarctic indicates that the land and the ocean along the coastline are warming up. Representative numbers for warming at the surface further inland are much more complicated due to the vast size of the continent. The Automated Weather Station AWS8989 has been reporting temperatures from Concordia Station on DomeC in Antarctica every 10 minutes since 1996. AWS8989 is located about 1 mile from the power plant at Concordia Station. We compare the surface temperatures at DomeC deduced from Atmospheric Infrared Sounder (AIRS) and Infrared Atmospheric Sounding Interferometer (IASI) data to the surface temperature reported by Automated Weather Station AWS8989 for the year between May 1, 2007 and April 30, 2008. AIRS and IASI measure the mean skin brightness temperature in a 50-km-radius circle from DomeC, while the AWS reports the temperature of the air at 3 meters above the surface. The AIRS and IASI measurements agree within 50 mK over the entire temperature range from 190 K in the winter to 245 K in the summer, but consistently report a colder temperature than the AWS8989. The warm bias of AWS8989 is season dependent, changing from 1.5 K warm in the winter to 5.5 K warm in the summer. Comparison of AIRS data in 2005 with a temporary Italian AWS (Aumann et al. 2006) and located several miles upwind from the power station, showed no significant temperature bias throughout the year 2005. The warm readings of AWS8989 are likely due the combination of a season-independent 1.5 K warm calibration bias in the AWS8989 sensor plus thermal contamination of the AWS8989 site. This heat island effect ranges from near zero during the low-activity winter months to about 4 K during the summer months with the highest activity at Concordia Station. The fact that activities at DomeC are increasing makes surface temperature trends from AWS8989 suspect. AIRS and IASI are hyperspectral infrared sounders designed in support of weather forecasting and climate research. AIRS was launched in May 2002 on the EOS Aqua spacecraft into a 704 km altitude polar sun- synchronous orbit with a 1:30 PM ascending node and is expected to provide data through 2015. IASI was launched in October 2006 into an 825 km altitude polar sun-synchronous orbit with a 9:30 AM ascending node with an expected 5-year lifetime.

  15. Fitting the observed changes of global surface temperatures

    NASA Astrophysics Data System (ADS)

    Courtillot, V.; Le Mouël, J.; Kossobokov, V. G.; Gibert, D.; Lopes, F.

    2012-12-01

    The quality of the fit of a trivial or, conversely, delicately-designed model to the observed natural phenomena is the fundamental pillar stone of any forecasting, including forecasting of the Earth's Climate. Using precise mathematical and logical systems outside their range of applicability can be scientifically groundless, unwise, and even dangerous. The temperature data sets are naturally in the basis of any hypothesizing on variability and forecasting the Earth's Climate. Leaving open the question of the global temperature definitions and their determination (T), we have analyzed hemispheric and global monthly temperature anomaly series produced by the Climate Research Unit of the University of East Anglia (CRUTEM4 database) and more recently by the Berkeley Earth Surface Temperature consortium (BEST database). We first fit the data in 1850-2010 with polynomials of degrees 1 to 9 and compare it with exponential fit by the adjusted R-squared criterion that takes into consideration the number of free parameters of the model. In all the cases considered, the adjusted R-squared values for polynomials are larger than for the exponential as soon as the degree exceeds 1 or 2. The polynomial fits become even more satisfactory as soon as degree 5 or 6 is reached. Extrapolations of these trends outside of the data domain show quick divergence. For example, the CRUTEM4vNH fit in the decade 2010-2020, for degrees 2 to 5, rises steeply then, for degrees 6 to 9, reverses to steep decreasing: the reversal in extrapolated trends arises from improved ability to fit the observed "~60-yr" wave in 150 years of data prior to 2010. The extrapolations prior to 1850 are even more erratic, linked with the increased dispersion of the early data. When focusing the analysis of fits on 1900-2010 we find that the apparent oscillations of T can be modeled by a series of linear segments: An optimal fit suggests 4 slope breaks indicating two clear transitions in 1940 and 1975, and two that are less certain in 1905 and 2005. Interestingly, the Pacific Decadal Oscillation index underwent major changes around 1940-1950 and 1974-1984, i.e. the time of the breaks in slope of the T curve, suggesting a good correlation at the multi-decadal scale between the derivatives of T and PDO index. Therefore, one may speculate that the Earth's climate system may have entered a new multi-decadal regime in the last years of the 20th century and we should expect global temperature to remain constant or decrease slightly while the PDO index remains dominantly negative up to about 2030.

  16. Suprathermal ions ahead of interplanetary shocks: New observations and critical instrumentation required for future space weather monitoring

    Microsoft Academic Search

    A. Posner; N. A. Schwadron; D. J. McComas; E. C. Roelof; A. B. Galvin

    2004-01-01

    We report new findings on the low-energy ion population associated with interplanetary (IP) shocks based on Wind\\/Suprathermal Ion Composition Spectrometer (STICS) observations. Suprathermal ions (6–200 keV) are present in the upstream region of most (86%) IP shocks at 1 AU. These foreshock ions are characterized by (1) median energy >25 keV, that is, higher than a thermal distribution; (2) spectra

  17. An assessment of buoy-derived and numerical weather prediction surface heat fluxes in the tropical Pacific

    Microsoft Academic Search

    Meghan F. Cronin; Christopher W. Fairall; Michael J. McPhaden

    2006-01-01

    As part of the Eastern Pacific Investigation of Climate Processes program, from 2000 through 2003, the easternmost 95°W Tropical Atmosphere Ocean (TAO) moorings were enhanced to provide time series of net surface heat flux, and the National Oceanic and Atmospheric Administration ship maintaining the 95°W and 110°W TAO lines was enhanced to monitor surface heat fluxes and atmospheric boundary layer

  18. Graphical tools for TV weather presentation

    Microsoft Academic Search

    M. Najman

    2010-01-01

    Contemporary meteorology and its media presentation faces in my opinion following key tasks: - Delivering the meteorological information to the end user\\/spectator in understandable and modern fashion, which follows industry standard of video output (HD, 16:9) - Besides weather icons show also the outputs of numerical weather prediction models, climatological data, satellite and radar images, observed weather as actual as

  19. Weather Science Hotlist

    NSDL National Science Digital Library

    1969-12-31

    The Franklin Institute Online offers the metadata Web site Weather Science Hotlist. The page contains dozens of links organized into ten topics that include Online Exhibits, Weather Right Now, Background Information, Severe Weather, El Nino/ La Nina, Historical Weather, Career Connections, Activities, Atmosphere, and Weather Forecasting. A great source for anyone looking for online weather information.

  20. Weather Cycles

    NSDL National Science Digital Library

    Mrs. Mitchell

    2010-09-23

    We are professionals in the teaching profession. We designed this project for children ranging from 4th grade to 6th grade. This project explores factors that help create severe winter weather. An interactive simulation provides hands-on experience, followed by guiding questions and resource exploration. YOU WILL NEED: Paper with copied questions, Overhead projector and Students broken up into groups of 3. Form groups of three. Have each group explore the following simulation: Weather Maker Simulator Have students use the simulation to answer the following questions on paper. They should be discussing the questions in their groups. 1. In general, when are winds formed? 2. When winds are blowing, how can you get them to stop? 3. What ...

  1. Estimation of Swiss methane emissions by near surface observations and inverse modeling

    NASA Astrophysics Data System (ADS)

    Henne, Stephan; Brian, Oney; Leuenberger, Markus; Bamberger, Ines; Eugster, Werner; Steinbacher, Martin; Meinhardt, Frank; Brunner, Dominik

    2015-04-01

    On a global scale methane (CH4) is the second most important long-lived greenhouse gas. It is released from both natural and anthropogenic processes and its atmospheric burden has more than doubled since preindustrial times. Current CH4 emission estimates are associated with comparatively large uncertainties both globally and regionally. For example, the Swiss national greenhouse gas inventory assigns an uncertainty of 18% to the country total anthropogenic CH4 emissions as compared to only 3% for anthropogenic CO2 emissions. In Switzerland, CH4 is thought to be mainly released by agricultural activities (ruminants and manure management >80%), while natural emissions from wetlands and wild animals represent a minor source (~3 %). The country total and especially the spatial distribution of CH4 emission within Switzerland strongly differs between the national and different European scale inventories. To validate the 'bottom-up' Swiss CH4 emission estimate and to reduce its uncertainty both in total and spatially, 'top-down' methods combining atmospheric CH4 observations and regional scale transport simulations can be used. Here, we analyse continuous, near surface observations of CH4 concentrations as collected within the newly established CarboCountCH measurement network (http://www.carbocount.ch). The network consists of 4 sites situated on the Swiss Plateau, comprising a tall tower site (217 m), two elevated (mountaintop) sites and a small tower site (32 m) in flat terrain. In addition, continuous CH4 observations from the nearby high-altitude site Jungfraujoch (Alps) and the mountaintop site Schauinsland (Germany) were used. Two inversion frameworks were applied to the CH4 observations in combination with source sensitivities (footprints) calculated with the regional scale version of the Lagrangian Particle Dispersion Model FLEXPART. One inversion system was based on a Bayesian framework, while the other utilized an extended Kalman filter approach. The transport model was driven by analysis fields from the non-hydrostatic numerical weather predication model COSMO at horizontal resolutions of up to 7 km x 7 km. As a result spatially resolved, annual mean CH4 fluxes for Switzerland were obtained. In general total Swiss CH4 emission remained close to the 'bottom-up' estimates, while considerable shifts in the regional distribution of the emissions were obtained. Reductions in CH4 emissions, as compared to the prior estimates, were established in regions with large emissions from ruminants, while increases resulted in the Western part of the Swiss Plateau, which is dominated by mixture of large water bodies and crop and vegetable farming. Sensitivity inversions were applied to assess the overall robustness and the uncertainty of the inversion system.

  2. Surface Reflectance of Mercury from MESSENGER Orbital Observations

    NASA Astrophysics Data System (ADS)

    Izenberg, N. R.; Holsclaw, G. M.; Domingue, D. L.; McClintock, W. E.; Blewett, D. T.; Kochte, M. C.; Helbert, J.; Sprague, A. L.; Vilas, F.; Solomon, S. C.

    2011-10-01

    The MESSENGER spacecraft entered orbit around Mercury on 18 March 2011, beginning a year-long investigation of the innermost planet. We present initial findings from the orbital investigation with the spacecraft's surface composition spectrometer, which obtained over 400,000 resolved reflectance spectra of the surface (spanning the wavelength range 320-1450 nm) in the first 10 weeks of orbital operations.

  3. Arctic Sea Ice Hits Record Low--Extreme Weather to Come? Global warming to blame for highest observed decline, scientists say.

    E-print Network

    South Bohemia, University of

    Arctic Sea Ice Hits Record Low--Extreme Weather to Come? Global warming to blame for highest" the previous record, set in 2007. The chief culprit? Global warming. The potential upshot? Longer and more intense extreme-weather events such as heat waves, cold spells, and droughts. On Monday, researchers

  4. Space Weathering on Airless Bodies

    NASA Astrophysics Data System (ADS)

    Pieters, C. M.; Blewett, D. T.; Hiroi, T.; Marchi, S.; McFadden, L. A.; Noble, S. K.; De Sanctis, M. C.; Taylor, L. A.; Reddy, V.

    2012-12-01

    Space weathering refers to an array of processes that measurably alter the character of surfaces that are exposed to the space environment with time. Important observations and constraints come from integration of ground truth sample information and remotely sensed data for the surface. Currently, such combined sample and remote data are available for the Moon, a few near-Earth asteroids (NEAs), and Vesta. Although common processes exist on every planetary body visited, the character of surface alteration by space weathering on airless bodies is very dependent on the particular space environment and the geology and composition of the host. For the Moon, lunar samples have provided a direct link between exposure to the space environment and the development and accumulation of nanophase reduced iron (npFe^0) on soil grains [1]. The optical properties of npFe^0 are well defined experimentally [2]. The resulting effects on lunar materials include reduction of diagnostic absorption bands, prominence of a red-sloped near-infrared (NIR) continuum, and lower albedo [3]. For Eros and Hyabusa, two NEAs visited by spacecraft, similar, but less pronounced optical effects are observed [4]. The in situ Eros measurements and returned Hyabusa samples confirm both bodies are ordinary chondritic in composition despite the optical alteration of their surface [5]. The main-belt proto-planet Vesta has long been associated with HED basaltic achondrite meteorites [6]. Data from Dawn reveal an anti-correlation between mineral band strength and albedo often observed around fresh craters. However, no association is seen with NIR continuum slope implying little development of significant npFe^0 [7]. Several physical and compositional reasons that hinder npFe^0 creation on Vesta are now recognized; alteration processes are instead more linked with dispersal of opaques and regolith mixing processes [7, 8]. Space weathering and evolution of the optical properties of regolith on airless bodies include the following general principles: A. Accumulation of nanophase opaque coatings on regolith grains with time is a common process and involves solar wind bombardment and/or micrometeoroid vaporization. This may be more dominant in the inner solar system. B. Although recent impacts often produce local heterogeneity at a crater, repeated impact mixing by smaller events results in apparent surficial homogenization over time. There is a suggestion that regolith mixing may be dominant for low-gravity regimes. Common related products involve impact darkening that creates and disperses micron-scale opaques [9] that darken but do not 'redden' the surface. C. Surface gravity and electrostatic forces strongly affect the development and retention of space weathering products. These are currently poorly quantified but steady-state processes appear to provide regional uniformity. References: 1. Keller & McKay, GCA, 1997; Taylor et al., JGR, 2001; 2010; Noble et al., MaPS, 2001. 2. Sasaki et al., Nature, 2001; Noble et al., Icarus, 2007. 3 Pieters et al., MaPS, 2000; Hapke JGR, 2001. 4. Clark et al., MaPS, 2001; Binzel et al., MaPS, 2001; Hiroi et al., Nature, 2006. 5. Trombke et al., Science, 2000; Nakamura et al., Science, 2011. 6. McCord et al., Science, 1970; De Sanctis et al., Science, 2012. 7. Pieters et al., Nature in press, 2012. 8. McCord et al., Nature in press; Reddy et al., Icarus, submitted. 9. Britt & Pieters, GCA, 1994.

  5. Climate Central World Weather Attribution (WWA) project: Real-time extreme weather event attribution analysis

    NASA Astrophysics Data System (ADS)

    Haustein, Karsten; Otto, Friederike; Uhe, Peter; Allen, Myles; Cullen, Heidi

    2015-04-01

    Extreme weather detection and attribution analysis has emerged as a core theme in climate science over the last decade or so. By using a combination of observational data and climate models it is possible to identify the role of climate change in certain types of extreme weather events such as sea level rise and its contribution to storm surges, extreme heat events and droughts or heavy rainfall and flood events. These analyses are usually carried out after an extreme event has occurred when reanalysis and observational data become available. The Climate Central WWA project will exploit the increasing forecast skill of seasonal forecast prediction systems such as the UK MetOffice GloSea5 (Global seasonal forecasting system) ensemble forecasting method. This way, the current weather can be fed into climate models to simulate large ensembles of possible weather scenarios before an event has fully emerged yet. This effort runs along parallel and intersecting tracks of science and communications that involve research, message development and testing, staged socialization of attribution science with key audiences, and dissemination. The method we employ uses a very large ensemble of simulations of regional climate models to run two different analyses: one to represent the current climate as it was observed, and one to represent the same events in the world that might have been without human-induced climate change. For the weather "as observed" experiment, the atmospheric model uses observed sea surface temperature (SST) data from GloSea5 (currently) and present-day atmospheric gas concentrations to simulate weather events that are possible given the observed climate conditions. The weather in the "world that might have been" experiments is obtained by removing the anthropogenic forcing from the observed SSTs, thereby simulating a counterfactual world without human activity. The anthropogenic forcing is obtained by comparing the CMIP5 historical and natural simulations from a variety of CMIP5 model ensembles. Here, we present results for the UK 2013/14 winter floods as proof of concept and we show validation and testing results that demonstrate the robustness of our method. We also revisit the record temperatures over Europe in 2014 and present a detailed analysis of this attribution exercise as it is one of the events to demonstrate that we can make a sensible statement of how the odds for such a year to occur have changed while it still unfolds.

  6. Weathering crusts on peridotite

    NASA Astrophysics Data System (ADS)

    Bucher, Kurt; Stober, Ingrid; Müller-Sigmund, Hiltrud

    2015-05-01

    Chemical weathering of dark-green massive peridotite, including partly serpentinized peridotite, produces a distinct and remarkable brown weathering rind when exposed to the atmosphere long enough. The structure and mineral composition of crusts on rocks from the Ronda peridotite, Spain, have been studied in some detail. The generic overall weathering reaction serpentinized peridotite + rainwater = weathering rind + runoff water describes the crust-forming process. This hydration reaction depends on water supply from the outcrop surface to the reaction front separating green peridotite from the brown crust. The reaction pauses after drying and resumes at the front after wetting. The overall net reaction transforms olivine to serpentine in a volume-conserving replacement reaction. The crust formation can be viewed as secondary serpentinization of peridotite that has been strongly altered by primary hydrothermal serpentinization. The reaction stoichiometry of the crust-related serpentinization is preserved and reflected by the composition of runoff waters in the peridotite massif. The brown color of the rind is caused by amorphous Fe(III) hydroxide, a side product from the oxidation of Fe(II) released by the dissolution of fayalite component in olivine.

  7. Observation of surface plasmons by transition radiation from smooth aluminium films

    E-print Network

    Boyer, Edmond

    L-167 Observation of surface plasmons by transition radiation from smooth aluminium films A'une résonance due aux plasmons de surface, dans le spectre du rayonnement de transition de films d We report the first observation of a strong resonance due to surface plasmons in the transition radia

  8. Why are climate models reproducing the observed global surface warming so well?

    E-print Network

    Fischlin, Andreas

    Why are climate models reproducing the observed global surface warming so well? Reto Knutti1 global surface warming so well?, Geophys. Res. Lett., 35, L18704, doi:10.1029/ 2008GL034932. 1 models reproduce the observed surface warming better than one would expect given the uncertainties

  9. Aquarius Observations of Sea Surface Salinity - Duration: 31 seconds.

    NASA Video Gallery

    This visualization shows changes in global sea surface salinity, as measured by NASAâ??s Aquarius instrument aboard the Aquarius/SAC-D spacecraft, from December 2011 through December 2012. Red repr...

  10. Experimental Observation of Bohr's Nonlinear Fluidic Surface Oscillation

    E-print Network

    Moon, Songky; Kwak, Hojeong; Yang, Juhee; Lee, Sang-Bum; Kim, Soyun; An, Kyungwon

    2015-01-01

    Niels Bohr in the early stage of his career developed a nonlinear theory of fluidic surface oscillation in order to study surface tension of liquids. His theory includes the nonlinear interaction between multipolar surface oscillation modes, surpassing the linear theory of Rayleigh and Lamb. It predicts a specific normalized magnitude of $0.41\\dot{6}\\eta^2$ for an octapolar component, nonlinearly induced by a quadrupolar one with a magnitude of $\\eta$ much less than unity. No experimental confirmation on this prediction has been reported. Nonetheless, accurate determination of multipolar components is important as in optical fiber spinning, film blowing and recently in optofluidic microcavities for ray and wave chaos studies and photonics applications. Here, we report experimental verification of his theory. By using optical forward diffraction, we measured the cross-sectional boundary profiles at extreme positions of a surface-oscillating liquid column ejected from a deformed microscopic orifice. We obtained...

  11. Land Surface Hydrological Processes: Remote Sensing Observations and

    E-print Network

    Washington at Seattle, University of

    , Endangered Species ...... One mission is to understand and predict land surface hydrological processes Reflectance Temperature Veg. Index Land Use Fire LAI/FPAR Albedo Snow Photos Images ...... Gravity field

  12. New IUE Observations of Unique Asteroids & Asteroid Surface Calibration Targets

    Microsoft Academic Search

    S. Alan Stern

    1993-01-01

    We propose that IUE expand the first-order reconnaissance of non-icy planetary surface properties in the mid-ultraviolet by obtaining the UV spectra of (i) a set of asteroids visited by spacecraft, (ii) well characterized lunar surfaces, and (iii) a pair of objects making unique apparitions in 1993-1994. None of the proposed targets (including the lunar terrains, as we describe below) have

  13. H I observations of giant low surface brightness galaxies

    Microsoft Academic Search

    L. D. Matthews; W. van Driel; D. Monnier-Ragaigne

    2001-01-01

    We have used the Nançay Radio Telescope to obtain new global H I data for 16 giant low surface brightness (LSB) galaxies. Our targets have optical luminosities and disk scale lengths at the high end for spiral galaxies (LB~1010 Lsun and h_r>~ 6 kpc for H0=75 km s-1 Mpc-1), but they have diffuse stellar disks, with mean disk surface brightnesses

  14. Surface moisture and satellite microwave observations in semiarid southern Africa

    Microsoft Academic Search

    M. Owe; A. T. C. Chang; A. A. Van de Griend

    1992-01-01

    Nimbus 7 scanning multichannel microwave radiometer 6.6-GHz passive microwave data were studied in relation to large-scale soil moisture estimates over a 3-year period in southeastern Bostwana. An extensive data base of weekly surface soil moisture measurements was used with meteorological data to estimate pixel average soil moisture on a daily basis. The influence of the vegetation canopy on the surface

  15. Dynamical contibution of Mean Potential Vorticity pseudo-observations derived from MetOp/GOME2 Ozone data into weather forecast, a Mediterranean High Precipitation Event study.

    NASA Astrophysics Data System (ADS)

    Sbii, Siham; Zazoui, Mimoun; Semane, Noureddine

    2015-04-01

    In the absence of observations covering the upper troposphere - lower stratophere, headquarters of several disturbances, and knowing that satellites are uniquely capable of providing uniform data coverage globally, a methodology is followed [1] to convert Total Column Ozone, observed by MetOp/GOME2, into pseudo-observations of Mean Potential Vorticity (MPV). The aim is to study the dynamical impact of Ozone data in the prediction of a Mediterranean Heavy Precipitation Event observed during 28-29 September 2012 in the context of HYMEX1. This study builds on a previously described methodology [2] that generates numerical weather prediction model initial conditions from ozone data. Indeed, the assimilation of MPV in a 3D-var framework is based on a linear regression between observed Ozone and vertical integrated Ertel PV. The latter is calculated using dynamical fields from the moroccan operational limited area model ALADIN-MAROC according to [3]: ?? fp p0 -R ?U ?V P V = - g?a?p- g-R-(p )Cp [(?p-)2 + (?p-)2] (1) Where ?a is the vertical component of the absolute vorticity, U and V the horizontal wind components, ? the potential temperature, R gas constant, Cp specific heat at constant pressure, p the pressure, p0 a reference pressure, g the gravity and f is the Coriolis parameter. The MPV is estimated using the following expression: --1--? P2 M PV = P1 - P2 P P V.?p 1 (2) With P1 = 500hPa and P2 = 100hPa In the present study, the linear regression is performed over September 2012 with a correlation coefficient of 0.8265 and is described as follows: M P V = 5.314610- 2 *O3 - 13.445 (3) where O3 and MPV are given in Dobson Unit (DU) and PVU (1 PV U = 10-6 m2 K kg-1 s-1), respectively. It is found that the ozone-influenced upper-level initializing fields affect the precipitation forecast, as diagnosed by a comparison with the ECMWF model. References [1] S. Sbii, N. Semane, Y. Michel, P. Arbogast and M. Zazoui (2012). Using METOP/GOME-2 data and MSG ozone data as Potential Vorticity pseudo-observations, Geophysical Research Abstracts Vol. 14, EGU2012-8926, EGU General Assembly. [2] S. Sbii, M. Zazoui, N. Semane, Y. Michel and P. Arbogast (2013). Exploring the Potential Application of MetOp/GOME2 Ozone Data to Weather Analysis.IJCSI, Vol. 10, Issue 2, No 3, March 2013: 260-263. [3] Guerin, R., Desroziers, G. and Arbogast, P. (2006). 4D-Var analysis of potential vorticity pseudo-observations. Q.J.R. Meteorol. Soc., 132: 1283-1298.

  16. A Global Merged LandAirSea Surface Temperature Reconstruction Based on Historical Observations (18801997)

    E-print Network

    A Global Merged Land­Air­Sea Surface Temperature Reconstruction Based on Historical Observations 2004) ABSTRACT A merged land­air­sea surface temperature reconstruction analysis is developed an analy- sis of the merged surface temperature is produced. The analysis uses a sea surface temperature

  17. Comparison of Arctic clouds between European Center for Medium-Range Weather Forecasts simulations and Atmospheric Radiation Measurement Climate Research Facility long-term observations at the North Slope of Alaska Barrow site

    NASA Astrophysics Data System (ADS)

    Zhao, Ming; Wang, Zhien

    2010-12-01

    This study evaluated the European Center for Medium-Range Weather Forecasts (ECMWF) model-simulated clouds and boundary layer (BL) properties based upon Atmospheric Radiation Measurement Climate Research Facility observations at the North Slope of Alaska site during 1999-2007. The ECMWF model-simulated near-surface humidity had seasonal dependent biases as large as 20%, while also experiencing difficulty representing BL temperature inversion height and strength during the transition seasons. Although the ECMWF model captured the seasonal variation of surface heat fluxes, it had sensible heat flux biases over 20 W m-2 in most of the cold months. Furthermore, even though the model captured the general seasonal variations of low-level cloud fraction (LCF) and liquid water path (LWP), it still overestimated the LCF by 20% or more and underestimated the LWP over 50% in the cold season. On average, the ECMWF model underestimated LWP by ˜30 g m-2 but more accurately predicted ice water path for BL clouds. For BL mixed-phase clouds, the model predicted water-ice mass partition was significantly lower than the observations, largely due to the temperature dependence of water-ice mass partition used in the model. The ECMWF model captured the general response of cloud fraction and LWP on large-scale vertical motion changes but overpredicted the magnitude of the difference, especially for LWP. The new cloud and BL schemes of the ECMWF model that were implemented after 2003 only resulted in minor improvements in BL cloud simulations in summer. These results indicate that significant improvements in cold season BL and mixed-phase cloud processes in the model are needed.

  18. The weathering of oil after the Deepwater Horizon oil spill: insights from the chemical composition of the oil from the sea surface, salt marshes and sediments

    NASA Astrophysics Data System (ADS)

    Liu, Zhanfei; Liu, Jiqing; Zhu, Qingzhi; Wu, Wei

    2012-09-01

    The oil released during the Deepwater Horizon (DWH) oil spill may have both short- and long-time impacts on the northern Gulf of Mexico ecosystems. An understanding of how the composition and concentration of the oil are altered by weathering, including chemical, physical and biological processes, is needed to evaluate the oil toxicity and impact on the ecosystem in the northern Gulf of Mexico. This study examined petroleum hydrocarbons in oil mousse collected from the sea surface and salt marshes, and in oil deposited in sediments adjacent to the wellhead after the DWH oil spill. Oil mousses were collected at two stations (OSS and CT, located 130 and 85 km away from the wellhead, respectively) in May 2010, and two sediment samples from stations SG and SC, within 6 km of the wellhead, in May 2011. We also collected oil mousse from salt marshes at Marsh Point (MP), Mississippi, 186 km away from the wellhead in July 2010. In these samples, n-alkanes, polycyclic aromatic hydrocarbons (PAHs), alkylated PAHs, BTEX (collective name of benzene, toluene, ethylbenzene and p-, m-, and o-xylenes), C3-benzenes and trace metals were measured to examine how the oil was altered chemically. The chemical analysis indicates that the oil mousses underwent different degrees of weathering with the pattern of OSS < CT < MP. This pattern is consistent with the projected oil mousse movement from the accident site to salt marshes. Also, the contents of trace metals Al, V, Cr, Fe, Mn, Ni, Co, Cu, As and Pb in the oil mousse generally increased along the way to the salt marshes, indicating that these trace metals were perhaps aggregated into the oil mousse during the transport. Petroleum hydrocarbon data reveal that the oil deposited in sediments underwent only light to moderate degradation one year after the DWH oil spill, as supported by the presence of short-chained n-alkanes (C10-C 15), BTEX and C 3-benzenes. The weathering of oil in sediment may result from biological degradation and dissolution, evidenced by the preferential loss of mid-chained n-alkanes C16-C 27, lower ratios of n-C 17/Pr and n-C 18/Ph , and preferential loss of PAHs relative to alkylated PAHs.

  19. User's Guide, software for reduction and analysis of daily weather and surface-water data: Tools for time series analysis of precipitation, temperature, and streamflow data

    USGS Publications Warehouse

    Hereford, Richard

    2006-01-01

    The software described here is used to process and analyze daily weather and surface-water data. The programs are refinements of earlier versions that include minor corrections and routines to calculate frequencies above a threshold on an annual or seasonal basis. Earlier versions of this software were used successfully to analyze historical precipitation patterns of the Mojave Desert and the southern Colorado Plateau regions, ecosystem response to climate variation, and variation of sediment-runoff frequency related to climate (Hereford and others, 2003; 2004; in press; Griffiths and others, 2006). The main program described here (Day_Cli_Ann_v5.3) uses daily data to develop a time series of various statistics for a user specified accounting period such as a year or season. The statistics include averages and totals, but the emphasis is on the frequency of occurrence in days of relatively rare weather or runoff events. These statistics are indices of climate variation; for a discussion of climate indices, see the Climate Research Unit website of the University of East Anglia (http://www.cru.uea.ac.uk/projects/stardex/) and the Climate Change Indices web site (http://cccma.seos.uvic.ca/ETCCDMI/indices.html). Specifically, the indices computed with this software are the frequency of high intensity 24-hour rainfall, unusually warm temperature, and unusually high runoff. These rare, or extreme events, are those greater than the 90th percentile of precipitation, streamflow, or temperature computed for the period of record of weather or gaging stations. If they cluster in time over several decades, extreme events may produce detectable change in the physical landscape and ecosystem of a given region. Although the software has been tested on a variety of data, as with any software, the user should carefully evaluate the results with their data. The programs were designed for the range of precipitation, temperature, and streamflow measurements expected in the semiarid Southwest United States. The user is encouraged to review the examples provided with the software. The software is written in Fortran 90 with Fortran 95 extensions and was compiled with the Digital Visual Fortran compiler version 6.6. The executables run on Windows 2000 and XP, and they operate in a MS-DOS console window that has only very simple graphical options such as font size and color, background color, and size of the window. Error trapping was not written into the programs. Typically, when an error occurs, the console window closes without a message.

  20. Seasonal and Interannual Variations of Ice Sheet Surface Elevation at the Summit of Greenland: Observed and Modeled

    NASA Technical Reports Server (NTRS)

    Zwally, H. Jay; Jun, Li; Koblinsky, Chester J. (Technical Monitor)

    2001-01-01

    Observed seasonal and interannual variations in the surface elevation over the summit of the Greenland ice sheet are modeled using a new temperature-dependent formulation of firn-densification and observed accumulation variations. The observed elevation variations are derived from ERS (European Remote Sensing)-1 and ERS-2 radar altimeter data for the period between April 1992 and April 1999. A multivariate linear/sine function is fitted to an elevation time series constructed from elevation differences measured by radar altimetry at orbital crossovers. The amplitude of the seasonal elevation cycle is 0.25 m peak-to-peak, with a maximum in winter and a minimum in summer. Inter-annually, the elevation decreases to a minimum in 1995, followed by an increase to 1999, with an overall average increase of 4.2 cm a(exp -1) for 1992 to 1999. Our densification formulation uses an initial field-density profile, the AWS (automatic weather station) surface temperature record, and a temperature-dependent constitutive relation for the densification that is based on laboratory measurements of crystal growth rates. The rate constant and the activation energy commonly used in the Arrhenius-type constitutive relation for firn densification are also temperature dependent, giving a stronger temperature and seasonal amplitudes about 10 times greater than previous densification formulations. Summer temperatures are most important, because of the strong non-linear dependence on temperature. Much of firn densification and consequent surface lowering occurs within about three months of the summer season, followed by a surface build-up from snow accumulation until spring. Modeled interannual changes of the surface elevation, using the AWS measurements of surface temperature and accumulation and results of atmospheric modeling of precipitation variations, are in good agreement with the altimeter observations. In the model, the surface elevation decreases about 20 cm over the seven years due to more compaction driven by increasing summer temperatures. The minimum elevation in 1995 is driven mainly by a temporary accumulation decrease and secondarily by warmer temperatures. However, the overall elevation increase over the seven years is dominated by the accumulation increase in the later years.

  1. Space Weather for the DoD Warfighter: An Agency Level Update

    Microsoft Academic Search

    T. E. Nobis

    2006-01-01

    The Space Weather Operations Center (Space WOC) at the Air Force Weather Agency (AFWA) is the DoD Warfighter's source for operational space weather support. The Space WOC utilizes real-time space weather observations and model output to obtain the situational awareness necessary for the creation tailored space weather products to the warfighter. AFWA Personnel located within space weather programs and technology

  2. Particle aggregation in volcanic clouds from the 2009 eruption of Redoubt Volcano, Alaska: Observations of Doppler weather radar, satellite images and tephra-fall deposits

    NASA Astrophysics Data System (ADS)

    Schneider, D. J.; Wallace, K. L.; Mastin, L. G.

    2012-12-01

    The combined use of weather radar and thermal infrared satellite images provides complementary evidence that can be used to observe and interpret tephra-fall processes. Radar is ideal for characterizing coarse-grained tephra in the eruption column and proximal cloud, while thermal infrared satellite data are better able to characterize the fine-grained distal volcanic cloud. We present observations of radar, satellite images, and character of the tephra-fall deposits from the 2009 eruption of Redoubt Volcano, Alaska. Accretionary tephra-ice pellets (up to 9 mm in diameter) comprised of fine-grained ash (less than 63 micron diameter) were abundant in the many of the proximal tephra-fall deposits. The eruption column and proximal cloud from seventeen explosive events were observed using the MiniMax-250C (MM-250C) volcano-monitoring Doppler weather radar located 80 km from the vent. Radar reflectivity and radial Doppler velocity measurements were made of the column, every 70-90 seconds at a vertical resolution of about 2 km. Radar reflectivity is highly dependent upon particle size and to a lesser extent, concentration. At 80 km distance, the minimum detectable particle diameter for the MM-250C was about 0.2 mm for a mass concentration of 100 g/m3. Thus, the radar was able to observe the aggregate pellets, and not the fine-grained ash. Most of the explosive events were characterized by high radar reflectivity values of 50-60 dBZ in the central core of the eruption column and proximal cloud, which we interpret to be related to the rapid growth of accretionary tephra-ice pellets. Tephra-fall deposits extended for distances of several hundred kilometers and mapped to a minimum mass density of 10 g/m2. However, the MM-250C radar data were only able to observe the dispersed cloud for tens of kilometers from the source, which was well within the 1000 g/m2 isomass contour. Fine-grained ash was prematurely removed from the eruption cloud in proximal locations due to aggregate formation. The relative lack of fine-grained ash may account for the poor thermal infrared brightness temperature signals observed in satellite images for many of the distal volcanic clouds from the 2009 eruption, and possibly from the 1989-90 eruption as well. Time-series of radial Doppler velocity images documented the transition from turbulent mixing in the column to larger scale entrainment within the proximal cloud. Large scale entrainment begins to develop within minutes of eruption onset. Most of the eruption clouds from the explosive events reached the stratosphere, but the large scale entrainment appears to be better developed in the tropospheric portion of the cloud.

  3. Surface Analytical Observations During Construction and Initial Operation of TCSU

    NASA Astrophysics Data System (ADS)

    Tankut, A.; Vlases, G. C.; Miller, K. E.; Ohuchi, F. S.

    2009-06-01

    To minimize radiation-loss effects, preparation and in-situ conditioning of plasma-facing surfaces in the Translation Confinement and Sustainment Upgrade experiment (TSCU) was carried out with utmost attention. To assess the condition of the TCSU first walls during the construction and operation, chemical and morphological surface analysis techniques such as X-ray photoelectron spectroscopy (XPS), energy dispersive X-ray spectroscopy (EDS), and scanning electron microscopy (SEM) were utilized. Here we present a summary of the preliminary and ongoing work performed for TCSU wall-conditioning, including preparation of UHV compatible surfaces, glow discharge cleaning (GDC), and siliconization. Effective techniques were developed for cleaning various plasma-facing components, including Al flux rings, stainless steel chambers and components, and quartz surfaces, prior to their installation. Helium-GDC was tested and proved to be useful in reducing the plasma impurities; however, extended periods of GDC resulted in the coating of quartz surfaces due to the sputtering of neighboring stainless steel walls by energetic glow particles. In addition, as a wall conditioning technique, siliconization has been examined in a separate system dedicated for detailed analysis of the process.

  4. Weather Activities

    NSDL National Science Digital Library

    This entertaining, interactive website is the perfect tool to educate users about the basics of weather forecasting and reporting. The two educational modules, created by EdHeads, each contain three levels and are designed for grades four through nine. While discovering how to predict a three-day forecast, students learn about warm and cold fronts, wind direction and speed, high and low pressure systems, isobars, and humidity. Teachers can find a helpful guide discussing how best to use the site as well as providing an overview of science standards, lesson plans, and pre- and post-tests for students.

  5. Weather Tamers

    NSDL National Science Digital Library

    Donna R. Sterling

    2007-03-01

    Problem-based learning experiences that extend at least two weeks provide an opportunity for students to investigate a real-world problem while learning science content and skills in an exciting way. Meteorology provides a wealth of problems students can investigate while learning specific science concepts and skills found frequently in middle level national and state curricula standards. The hands-on activity described in this article helps students learn about the science behind weather events by planning, constructing, and testing models of cities exposed to a series of simulated hurricanes and tornado conditions.

  6. Destructive Weather

    NSDL National Science Digital Library

    alizabethirwin

    2010-11-03

    What are the effects of different types of destructive weather? Learn All About Hurricanes Record on your chart 3 things that you learned. Watch a Hurricane Video These are the devastating Effects of Hurricanes Learn All About Tornadoes Record on your chart 3 things that you learned. Watch a Tornado Video These are the devastating Effects of tornadoes Learn All About Thunderstorms Record on your chart 3 things that you learned. These are the devastating Effects of thunderstorms Follow these important tips To keep safe. ...

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

    Microsoft Academic Search

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

    2011-01-01

    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

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

    Microsoft Academic Search

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

    2011-01-01

    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

  9. Weather and climate needs for Lidar observations from space and concepts for their realization. [wind, temperature, moisture, and pressure data needs

    NASA Technical Reports Server (NTRS)

    Atlas, D.; Korb, C. L.

    1980-01-01

    The spectrum of weather and climate needs for Lidar observations from space is discussed with emphasis on the requirements for wind, temperature, moisture, and pressure data. It is shown that winds are required to realistically depict all atmospheric scales in the tropics and the smaller scales at higher latitudes, where both temperature and wind profiles are necessary. The need for means to estimate air-sea exchanges of sensible and latent heat also is noted. A concept for achieving this through a combination of Lidar cloud top heights and IR cloud top temperatures of cloud streets formed during cold air outbreaks over the warmer ocean is outlined. Recent theoretical feasibility studies concerning the profiling of temperatures, pressure, and humidity by differential absorption Lidar (DIAL) from space and expected accuracies are reviewed. An alternative approach to Doppler Lidar wind measurements also is presented. The concept involves the measurement of the displacement of the aerosol backscatter pattern, at constant heights, between two successive scans of the same area, one ahead of the spacecraft and the other behind it a few minutes later. Finally, an integrated space Lidar system capable of measuring temperature, pressure, humidity, and winds which combines the DIAL methods with the aerosol pattern displacement concept is described.

  10. Surface albedo observations at Gusev Crater and Meridiani Planum, Mars

    Microsoft Academic Search

    J. F. Bell III; M. S. Rice; J. R. Johnson; T. M. Hare

    2008-01-01

    During the Mars Exploration Rover mission, the Pancam instrument has periodically acquired large-scale panoramic images with its broadband (739 ± 338 nm) filter in order to estimate the Lambert bolometric albedo of the surface along each rover's traverse. In this work we present the full suite of such estimated albedo values measured to date by the Spirit and Opportunity rovers

  11. Progress on scanning field emission microscope development for surface observation

    E-print Network

    Istituto Nazionale di Fisica Nucleare (INFN)

    and the other is a chemical etched surface. The cathodes are kept in an ultra vacuum chamber at a typical and thermal conductivity, as well as its aptitude for precision machining. 2. Experimental setup of scanning mm rectangular plane. The sample is treated at 600 1C for 2 h in vacuum. The tip is positioned

  12. The Weather Dude

    NSDL National Science Digital Library

    Walker, Nick.

    2002-01-01

    The Weather Dude is a weather education Web site offered by meteorologist Nick Walker of The Weather Channel. For kids, the site offers a great online textbook entitled Weather Basics, which explains everything from precipitation to the seasons, using simple text and fun graphics. Other fun things for kids include weather songs, questions and quizzes, weather proverbs, and more. Teachers are also provided with helpful resources such as weather activity sheets and printable blank maps, as well as many other links to weather forecasts and information that will help make teaching about weather fun.

  13. KAGUYA Lunar Radar Sounder (LRS) observation of lunar surface echo and its calibration

    NASA Astrophysics Data System (ADS)

    Kobayashi, Takao; Ryeol Lee, Seung

    2015-04-01

    Lunar Radar Sounder (LRS) is an HF radar of which the center frequency of transmitted pulse is 5 MHz. LRS was installed to KAGUYA which flew to the Moon in 2007. During the operation period of 19 months, LRS performed radar sounding observation from the orbit at the nominal altitude of 100 km to cover whole surface of the Moon with its foot print. The total number of LRS observations (pulse transmissions) exceeded 10^8. We extracted the nadir surface echo out of each observation which made a surface echo map of the Moon, i.e. a mosaic image of the Moon of an HF frequency (5 MHz). The observed surface echoes carry information regarding lunar surface and that of shallow subsurface (near-surface) whose depth scale is smaller than the range resolution of the LRS (~ 150 m in vacuum). An inversion algorithm is applied to extract such information. However, inversion algorithms often assume a simple model of Fresnel reflection. One should remove the effect of surface roughness from the LRS data before practicing inversion. For this purpose, we carried out simulation of LRS observation to evaluate the surface roughness effect on the LRS data quantitatively. The simulation is based on Kirchhoff approximation theory. Digital Elevation Model (DEM) of KAGUYA Terrain Camera (TC) mission was used in the simulation to simulate the actual lunar terrain. LRS observation simulation was performed in the range from -90 to 70 degrees in longitude and in the range from -30 to 70 degrees in latitude at every 0.1 degree interval in both directions. The simulation revealed 1) LRS surface echo observation is sensible to the surface terrain: even wrinkle ridges and small craters are well recognized in the mosaic image of simulation surface echo map. 2) Little difference was found in the mosaic image of an old mare surface and a young mare surface. 3) However, apparent difference was found in the shape of the distribution functions of echo intensity of an old mare surface and a young mare surface. We used the simulation result to remove the surface roughness effect on the LRS data to obtain the plane surface echo intensity. The resultant data revealed 1) Highland surface presents weak echo intensity than mare surface. 2) Young mare surface presents more intense echo than old mare surface. 3) Some areas in maria presents significantly weak echo than surrounding mare surface. These findings are attributed to the property of near-surface subsurface. Our inversion found that the young mare surface material has larger permittivity than the old mare surface material.

  14. Heating from Below: Impacts on Weather and Climate Prediction

    NASA Astrophysics Data System (ADS)

    Fan, X.

    2009-05-01

    Upward geothermal heat flow has been proved by observations and applications to be exist and influence weather and climate at regional scales. However, it is not considered in the existing weather and climate models due to the lack of comprehensive observations and understandings. Soil temperature represents the soil energy state that is influenced by both downward and upward energy transfers. It is a major variable in land surface models, representing soil energy status, storage, and transfer. It serves as an important factor indicating the underlying surface heating condition for weather and climate forecasts. However, soil temperature observations have not been utilized in present weather and climate models to provide soil energy state, although long-term observations have been in existence for more than half a century. Therefore, the objectives of this study is: 1) to consider heating from below in numerical modeling; and 2) to utilized observed soil temperature data in initializing numerical model to conduct impact study. As the first step in climate impact study, the Weather Research and Forecasting (WRF) model is used to study the impacts of changes to the surface heating condition, derived from soil temperature observations, on regional weather simulations. Large biases are found, as compared to observations, in the European Centre for Medium-Range Weather Forecasts (ECMWF) 40-year reanalysis project (ERA-40) soil temperatures and in the lower boundary assumption adopted by the Noah land surface model. In six heavy rain cases studied herein, observed soil temperatures are used to initialize the land surface model and to provide a lower boundary condition at the bottom of the model soil layer. By analyzing the impacts from the incorporation of observed soil temperatures, the following major conclusions are drawn: 1) A consistent increase in the ground heat flux is found during the day, when the observed soil temperatures are used to correct the cold bias present in ERA-40. Soil temperature changes introduced at the initial time maintain positive values but gradually decrease in magnitude with time. Sensible and latent heat fluxes and the moisture flux experience an increase during the first six hours. 2) An increase in soil temperature impacts the air temperature through surface exchange, and near-surface moisture through evaporation. During the first two days, an increase in air temperature is seen across the region from the surface up to about 800 hPa (~1450 m). The maximum near-surface air temperature increase is found to be, averaged over all cases, 0.5 K on the first day and 0.3 K on the second day. 3) The strength of the low-level jet is affected by the changes described above and also by the consequent changes in horizontal gradients of pressure and thermal fields. Thus, the three-dimensional circulation is affected, in addition to changes seen in the humidity and thermal fields and the locations and intensities of precipitating systems. 4) Overall results indicate that the incorporation of observed soil temperatures introduces a persistent soil heating condition that is favorable to convective development and, consequently, improves the simulation of precipitation. The significant impacts on weather modeling imply that the heating from below may also have significant impact on regional climate. Future study of soil heating impacts on regional climate has been planned.

  15. Localized Weathering: Implications for Theoretical and Applied Studies

    Microsoft Academic Search

    Steven J. Gordon; Ronald I. Dorn

    2005-01-01

    In situ quantification of localized weathering processes on basalt flows in New Mexico and Hawaii demonstrates that small-area factors can be more important than other more readily observable factors. Further, it demonstrates that the factorial concept of the Pope Boundary-Layer weathering model is partially solvable, that organic weathering can accentuate glass weathering (with implications for climate models and storage of

  16. Detecting surface runoff location in a small catchment using distributed and simple observation method

    NASA Astrophysics Data System (ADS)

    Dehotin, Judicaël; Breil, Pascal; Braud, Isabelle; de Lavenne, Alban; Lagouy, Mickaël; Sarrazin, Benoît

    2015-06-01

    Surface runoff is one of the hydrological processes involved in floods, pollution transfer, soil erosion and mudslide. Many models allow the simulation and the mapping of surface runoff and erosion hazards. Field observations of this hydrological process are not common although they are crucial to evaluate surface runoff models and to investigate or assess different kinds of hazards linked to this process. In this study, a simple field monitoring network is implemented to assess the relevance of a surface runoff susceptibility mapping method. The network is based on spatially distributed observations (nine different locations in the catchment) of soil water content and rainfall events. These data are analyzed to determine if surface runoff occurs. Two surface runoff mechanisms are considered: surface runoff by saturation of the soil surface horizon and surface runoff by infiltration excess (also called hortonian runoff). The monitoring strategy includes continuous records of soil surface water content and rainfall with a 5 min time step. Soil infiltration capacity time series are calculated using field soil water content and in situ measurements of soil hydraulic conductivity. Comparison of soil infiltration capacity and rainfall intensity time series allows detecting the occurrence of surface runoff by infiltration-excess. Comparison of surface soil water content with saturated water content values allows detecting the occurrence of surface runoff by saturation of the soil surface horizon. Automatic records were complemented with direct field observations of surface runoff in the experimental catchment after each significant rainfall event. The presented observation method allows the identification of fast and short-lived surface runoff processes at a small spatial and temporal resolution in natural conditions. The results also highlight the relationship between surface runoff and factors usually integrated in surface runoff mapping such as topography, rainfall parameters, soil or land cover. This study opens interesting prospects for the use of spatially distributed measurement for surface runoff detection, spatially distributed hydrological models implementation and validation at a reasonable cost.

  17. Comparison of two inversion methods for retrieval of soil moisture and surface roughness from polarimetric radar observation of soil surfaces

    Microsoft Academic Search

    Yisok Oh

    2004-01-01

    This paper presents comparison of the direct inversion method (DIM) and the genetic algorithm-based inversion method (GAIM) for retrieval of soil moisture and surface roughness from polarimetric radar observation of soil surfaces. Those inversion methods are based on the polarimetric semiempirical model (PSEM), which was developed empirically to estimate the backscattering coefficients from the volumetric soil moisture content and the

  18. Observations of Turbulence in the Ocean Surface Boundary Layer: Energetics and Transport

    E-print Network

    Gerbi, Gregory P.

    Observations of turbulent kinetic energy (TKE) dynamics in the ocean surface boundary layer are presented here and compared with results from previous observational, numerical, and analytic studies. As in previous studies, ...

  19. Observation of star-shaped surface gravity waves.

    PubMed

    Rajchenbach, Jean; Clamond, Didier; Leroux, Alphonse

    2013-03-01

    We report a new type of standing gravity wave of large amplitude, having alternatively the shape of a star and of a polygon. This wave is observed by means of a laboratory experiment by vertically vibrating a tank. The symmetry of the star (i.e., the number of branches) is independent of the container form and size, and can be changed according to the amplitude and frequency of the vibration. We show that a nonlinear resonant coupling between three gravity waves can be envisaged to trigger the observed symmetry breaking, although more complex interactions certainly take place in the final periodic state. PMID:23496715

  20. Climatological data for clouds over the globe from surface observations, 1982--1991: The total cloud edition

    SciTech Connect

    Hahn, C.J. [Colorado Univ., Boulder, CO (United States). Cooperative Inst. for Research in Environmental Sciences] [Colorado Univ., Boulder, CO (United States). Cooperative Inst. for Research in Environmental Sciences; Warren, S.G. [Washington Univ., Seattle, WA (United States). Dept. of Atmospheric Sciences] [Washington Univ., Seattle, WA (United States). Dept. of Atmospheric Sciences; London, J. [Colorado Univ., Boulder, CO (United States). Dept. of Astrophysical, Planetary, and Atmospheric Sciences] [Colorado Univ., Boulder, CO (United States). Dept. of Astrophysical, Planetary, and Atmospheric Sciences

    1994-10-01

    Routine, surface synoptic weather reports from ships and land stations over the entire globe, for the ten-year period December 1981 through November 1991, were processed for total cloud cover and the frequencies of occurrence of clear sky, precipitation, and sky-obscured due to fog. Archived data, consisting of various annual, seasonal and monthly averages, are provided in grid boxes that are typically 2.5{degrees} {times} 2.5{degrees} for land and 5{degrees} {times} 5{degrees} for ocean. Day and nighttime averages are also given separately for each season. Several derived quantities, such as interannual variations and annual and diurnal harmonics, are provided as well. This data set incorporates an improved representation of nighttime cloudiness by utilizing only those nighttime observations for which the illuminance due to moonlight exceeds a specified threshold. This reduction in the night-detection bias increases the computed global average total cloud cover by about 2%. The impact on computed diurnal cycles is even greater, particularly over the oceans where is found, in contrast to previous surface-based climatologies, that cloudiness is often greater at night than during the day.

  1. Weather Prediction Models

    NASA Astrophysics Data System (ADS)

    Bacmeister, Julio T.

    Awareness of weather and concern about weather in the proximate future certainly must have accompanied the emergence of human self-consciousness. Although weather is a basic idea in human existence, it is difficult to define precisely.

  2. Winter Weather Checklists

    MedlinePLUS

    ... Health Matters What's New Preparation & Planning Disasters & Severe Weather Earthquakes Extreme Heat Floods Hurricanes Landslides Tornadoes Tsunamis ... Weather Information on Specific Types of Emergencies Winter Weather Checklists Language: English Español (Spanish) Recommend on Facebook ...

  3. Hot Weather Tips

    MedlinePLUS

    HOT Weather Tips Printer-friendly version We all suffer in hot weather. However, for elderly and disabled people and ... stress and following these tips for dealing with hot weather. Wear cool clothing: See that the person ...

  4. Accessing Recent Trend of Land Surface Temperature from Satellite Observations

    NASA Technical Reports Server (NTRS)

    Shen, Suhung; Leptoukh, Gregory G.; Romanov, Peter

    2011-01-01

    Land surface temperature (Ts) is an important element to measure the state of terrestrial ecosystems and to study surface energy budgets. In support of the land cover/land use change-related international program MAIRS (Monsoon Asia Integrated Regional Study), we have collected global monthly Ts measured by MODIS since the beginning of the missions. The MODIS Ts time series have approximately 11 years of data from Terra since 2000 and approximately 9 years of data from Aqua since 2002, which makes possible to study the recent climate, such as trend. In this study, monthly climatology from two platforms are calculated and compared with that from AIRS. The spatial patterns of Ts trends are accessed, focusing on the Eurasia region. Furthermore, MODIS Ts trends are compared with those from AIRS and NASA's atmospheric assimilation model, MERRA (Modern Era Retrospective-analysis for Research and Applications). The preliminary results indicate that the recent 8-year Ts trend shows an oscillation-type spatial variation over Eurasia. The pattern is consistent for data from MODIS, AIRS, and MERRA, with the positive center over Eastern Europe, and the negative center over Central Siberia. The calculated climatology and anomaly of MODIS Ts will be integrated into the online visualization system, Giovanni, at NASA GES DISC for easy use by scientists and general public.

  5. Accessing Recent Trend of Land Surface Temperature from Satellite Observations

    NASA Astrophysics Data System (ADS)

    Shen, S.; Leptoukh, G. G.; Romanov, P.

    2011-12-01

    Land surface temperature (LST) is an important element to measure the state of the terrestrial ecosystems and to study the surface energy budgets. In support of the land cover/land use change related international program MAIRS (Monsoon Asia Integrated Regional Study), we have collected the global monthly LST measured by MODIS since the beginning of the missions. The MODIS LST time series have ~11 years of data from Terra since 2000 and ~9 years of data from Aqua since 2002, which makes possible to study the recent climate, such as trend and variability. In this study, monthly climatology from two satellite platforms are calculated and compared. The spatial patterns of LST trends are accessed, focusing on the Asian Monsoon region. Furthermore, the MODIS LST trends are compared with the skin temperature trend from the NASA's atmospheric assimilation model, MERRA (MODERN ERA RETROSPECTIVE-ANALYSIS FOR RESEARCH AND APPLICATIONS), which has longer data record since 1979. The calculated climatology and anomaly of MODIS LST will be integrated into the online visualization system, Giovanni, at NASA GES DISC for easy access and use by scientists and general public.

  6. GPS observations of West Greenland Ice Sheet surface motion

    NASA Astrophysics Data System (ADS)

    Doyle, S. H.; Jones, G. A.; van As, D.; Fitzpatrick, A.; Dow, C. F.; Kulessa, B.; Hubbard, A.

    2011-12-01

    This study investigates the motion of the Russell Glacier Catchment in South West Greenland on a range of temporal and spatial scales. A network of dual frequency Global Positioning System (GPS) receivers, configured for continuous operation, was initiated in 2007. GPS measurements post-processed using Track software provide precise 3-D positions, which are used to derive high frequency ice-surface velocities. An array of passive seismometers consisting of six, three component geophones, sampling continuously at 1000 Hz, were deployed together with four GPS to investigate the local scale dynamics of a rapid lake drainage event. Whilst the interior of the ice sheet flows relatively slowly and shows negligible variation on diurnal, intra- or even inter-annual timescales, the margin experiences strong diurnal variations in ice velocity, coupled to surface melt and lake-tapping events. These short-term variations accrue into a seasonal summer-time speed-up, which has led to concerns over the stability of the ice sheet in a warming climate. The extent to which this melt-forcing of ice velocity extends inland, together with its evolution as the melt season progresses, is investigated.

  7. Using pan-Arctic, springtime, surface radiation observations to quantify atmospheric preconditioning processes that impact the sea ice melt season

    NASA Astrophysics Data System (ADS)

    Cox, Christopher; Uttal, Taneil; Starkweather, Sandy; Intrieri, Janet; Maturilli, Marion; Kustov, Vasily; Konopleva, Elena; Crepinsek, Sara; Long, Chuck

    2015-04-01

    Accurate, seasonal-scale forecasts of sea ice extent and distribution are critical for weather forecasting, transportation, the energy industry and local Arctic communities. Current forecasting methods capture an overall trend of decreasing sea ice on decadal scales, but do not reliably predict inter-annual variability. Recent work using satellite observations identified a relationship between spring-time, cloud modulated, shortwave radiation, and late season sea-ice extent; this relationship suggested an atmospheric preconditioning process that modulates the ice-albedo feedback and sets the stage for the melt season. Due to a general lack of emphasis on the role of the atmosphere on the evolution of the summer sea-ice, compounded by biases in cloud properties within models, this preconditioning process is poorly represented in current forecasting methods. Longwave and shortwave radiation data collected at the surface from stations surrounding the Arctic Basin as part of the Baseline Surface Radiation Network (BSRN) provide high-quality, continuous observations of the surface radiation budget. This includes downwelling fluxes and surface-cloud radiative interactions which cannot be directly acquired by satellites. These BSRN data are used to investigate the role of the atmosphere and clouds in seasonal scale variability of sea ice conditions, and the potential for improving predictability by incorporating these atmospheric observations into prediction strategies. We find that the downwelling fluxes measured at the land stations in spring are well correlated with sea ice conditions in September, especially in regions of the Arctic Ocean where late summer sea ice concentration has large inter-annual variability. Using observations of the total radiative flux (longwave + shortwave) at the surface, it is possible to make a seasonal sea-ice extent forecast that is within the range of uncertainty of forecasts currently incorporated into the Sea Ice Prediction Network (SIPN). Cloud variability and associated shortwave modulation of the ice-albedo feedback are found to be important, but the shortwave anomaly alone is insufficient unless combined with the longwave anomaly, which dominates and is opposite in sign in the presence of clouds. The amount of open water in the Western Arctic in September and October then controls cloud cover during the autumn freeze-up, potentially revealing a preconditioning mechanism that persists into the following melt season.

  8. Satellite Observations of Glacier Surface Velocities in Southeast Alaska

    NASA Astrophysics Data System (ADS)

    Elliott, J.; Melkonian, A. K.; Pritchard, M. E.

    2012-12-01

    Glaciers in southeast Alaska are undergoing rapid changes and are significant contributors to sea level rise. A key to understanding the ice dynamics is knowledge of the surface velocities, which can be used with ice thickness measurements to derive mass flux rates. For many glaciers in Alaska, surface velocity estimates either do not exist or are based on data that are at least a decade old. Here we present updated maps of glacier surface velocities in southeast Alaska produced through a pixel tracking technique using synthetic aperture radar data and high-resolution optical imagery. For glaciers with previous velocity estimates, we will compare the results and discuss possible implications for ice dynamics. We focus on Glacier Bay and the Stikine Icefield, which contain a number of fast-flowing tidewater glaciers including LeConte, Johns Hopkins, and La Perouse. For the Johns Hopkins, we will also examine the influence a massive landslide in June 2012 had on flow dynamics. Our velocity maps show that within Glacier Bay, the highest surface velocities occur on the tidewater glaciers. La Perouse, the only Glacier Bay glacier to calve directly into the Pacific Ocean, has maximum velocities of 3.5 - 4 m/day. Johns Hopkins Glacier shows 4 m/day velocities at both its terminus and in its upper reaches, with lower velocities of ~1-3 m/day in between those two regions. Further north, the Margerie Glacier has a maximum velocity of ~ 4.5 m/day in its upper reaches and a velocity of ~ 2 m/day at its terminus. Along the Grand Pacific terminus, the western terminus fed by the Ferris Glacier displays velocities of about 1 m/day while the eastern terminus has lower velocities of < 0.5 m/day. The lake terminating glaciers along the Pacific coast have overall lower surface velocities, but they display complex flow patterns. The Alsek Glacier displays maximum velocities of 2.5 m/day above where it divides into two branches. Velocities at the terminus of the northern branch reach 1 m/day while the terminus of the southern branch moves about 2 m/day. Grand Plateau Glacier also divides into two main branches, with a northern branch displaying peak velocities of 1.5 m/day and a southern branch flowing at a rate of 1 m/day. The Stikine Icefield contains a number of large tidewater glaciers showing maximum velocities near their termini. At the terminus of the South Sawyer Glacier, velocities reach a peak of about 2 m/day. Along the terminus of the Dawes Glacier, velocities reach 3.5 m/day. The Baird Glacier displays lower velocities of 1-1.5 m/day. LeConte Glacier has 2-3 m/day velocities in its upper regions with higher velocities near its terminus. In contrast to the pattern shown by the surrounding glaciers, the Great Glacier has a peak velocity of 2 m/day in the upper portion of the glacier and a velocity of only 0.5 m/day near its terminus.

  9. Explanation of the Observed Dearth of Three-Coordinated Al on -Alumina Surfaces

    E-print Network

    Pennycook, Steve

    Explanation of the Observed Dearth of Three-Coordinated Al on -Alumina Surfaces Karl Sohlberg revealed that -alumina surfaces do not contain any three-coordinated Al atoms, despite the fact-functional calculations of -alumina (110) surfaces that reveal a massive spontaneous reconstruction of the ideally

  10. Algorithms for extracting information from remote thermal-IR observations of the earth's surface

    Microsoft Academic Search

    J. M. Norman; M. Divakarla; N. S. Goel

    1995-01-01

    Thermal infrared remote sensing offers the possibility of monitoring the surface energy budget on regional and global scales. However, thermal observations have had limited utility because of difficulties associated with unknown surface emissivities, challenging atmospheric corrections, and the presence of numerous variables that affect the relationship between thermal radiance and the partitioning of energy fluxes at the surface. The importance

  11. Distance dependence of surface plasmon-coupled emission observed using Langmuir-Blodgett films

    E-print Network

    Enderlein, Jörg

    Distance dependence of surface plasmon-coupled emission observed using Langmuir-Blodgett films May 2007; accepted 31 May 2007; published online 22 June 2007 Surface plasmon-coupled emission SPCE of such interac- tions is the phenomenon of surface plasmon-coupled emis- sion SPCE . In SPCE an excited state

  12. Contact-mode AFM control with modified surface topography learning observer and PTC

    Microsoft Academic Search

    Hiroshi Fujimoto; Takashi Oshima

    2008-01-01

    Atomic force microscope (AFM) is the instrument that can measure the surface of samples on the nano-scale. Most of the controllers of commercial AFMs are designed by classic control theory. However, sophisticated control theory has been applied in recent academic papers. Authors have already proposed a surface topography learning observer (STLO) based on disturbance observer theory. However, this method is

  13. Characterization of surface-modified porous PVDF hollow fibers for refinery wastewater treatment using microscopic observation

    Microsoft Academic Search

    E. Yuliwati; A. F. Ismail; T. Matsuura; M. A. Kassim; M. S. Abdullah

    Microscopic observation was made to investigate the surface structure of porous polyvinylidene fluoride hollow fiber membranes. Field emission scanning electron microscopy (FESEM), atomic force microscopy (AFM), and the Guerout–Elford–Ferry equation applied for pure water permeation rate were used to determine the average pore sizes. As well, surface roughness parameters and nodule sizes were determined by AFM. The observed unmodified and

  14. Dynamic observation of needle-plane surface-discharge using the electro-optical Pockels effect

    Microsoft Academic Search

    Yongchang Zhu; Tatsuo Takada; Y. Inoue; Demin Tu

    1996-01-01

    Dynamic observation of surface charge distribution is the main advantage of the electro-optical Pockels effect technique over the dust figure technique, the photographic Lichtenberg figure technique, and the static potential probe scanning method. This technique is demonstrated here to observe the surface charge distribution deposited by partial discharge during application of one period of an 8 kV sinusoidal voltage to

  15. Observational Effects of Magnetism in O Stars: Surface Nitrogen Abundances

    NASA Technical Reports Server (NTRS)

    Martins, F.; Escolano, C.; Wade, G. A.; Donati, J. F.; Bouret, J. C.

    2011-01-01

    Aims. We investigate the surface nitrogen content of the six magnetic O stars known to date as well as of the early B-type star Tau Sco.. We compare these abundances to predictions of evolutionary models to isolate the effects of magnetic field on the transport of elements in stellar interiors. Methods. We conduct a quantitative spectroscopic analysis of the ample stars with state-of-the-art atmosphere models. We rely on high signal-to-noise ratio, high resolution optical spectra obtained with ESPADONS at CFHT and NARVAL at TBL. Atmosphere models and synthetic spectra are computed with the code CMFGEN. Values of N/H together with their uncertainties are determined and compared to predictions of evolutionary models. Results. We find that the magnetic stars can be divided into two groups: one with stars displaying no N enrichment (one object); and one with stars most likely showing extra N enrichment (5 objects). For one star (Ori C) no robust conclusion can be drawn due to its young age. The star with no N enrichment is the one with the weakest magnetic field, possibly of dynamo origin. It might be a star having experienced strong magnetic braking under the condition of solid body rotation, but its rotational velocity is still relatively large. The five stars with high N content were probably slow rotators on the zero age main sequence, but they have surface N/H typical of normal O stars, indicating that the presence of a (probably fossil) magnetic field leads to extra enrichment. These stars may have a strong differential rotation inducing shear mixing. Our results shOuld be viewed as a basis on which new theoretical simulations can rely to better understand the effect of magnetism on the evolution of massive stars.

  16. The Weathering of Micrometeorites

    NASA Astrophysics Data System (ADS)

    Van Ginneken, M.; Genge, M. J.; Folco, L.

    2014-09-01

    Despite the favorable conditions for their preservation, micrometeorites from Antarctica are affected by terrestrial weathering. Here we present a comprehensive work on the weathering of micrometeorites from Antarctica.

  17. SURFACE WAVES IN SOLAR GRANULATION OBSERVED WITH SUNRISE

    SciTech Connect

    Roth, M.; Franz, M.; Bello Gonzalez, N.; Berkefeld, T.; Schmidt, W. [Kiepenheuer-Institut fuer Sonnenphysik, Schoeneckstr. 6, 79104 Freiburg (Germany); Martinez Pillet, V.; Bonet, J. A. [Instituto de Astrofisica de Canarias, C/Via Lactea s/n, 38200 La Laguna, Tenerife (Spain); Gandorfer, A.; Barthol, P.; Solanki, S. K. [Max-Planck-Institut fuer Sonnensystemforschung, Max-Planck-Str. 2, 37191 Katlenburg-Lindau (Germany); Del Toro Iniesta, J. C. [Instituto de Astrofisica de Andalucia (CSIC), Apartado de Correos 3004, 18080 Granada (Spain); Domingo, V. [Grupo de Astronomia y Ciencias del Espacio, Universidad de Valencia, 46980 Paterna, Valencia (Spain); Knoelker, M., E-mail: mroth@kis.uni-freiburg.d [High Altitude Observatory, National Center for Atmospheric Research, P.O. Box 3000, Boulder, CO 80307-3000 (United States)

    2010-11-10

    Solar oscillations are expected to be excited by turbulent flows in the intergranular lanes near the solar surface. Time series recorded by the IMaX instrument on board the SUNRISE observatory reveal solar oscillations at high spatial resolution, which allow the study of the properties of oscillations with short wavelengths. We analyze two time series with synchronous recordings of Doppler velocity and continuum intensity images with durations of 32 minutes and 23 minutes, respectively, recorded close to the disk center of the Sun to study the propagation and excitation of solar acoustic oscillations. In the Doppler velocity data, both the standing acoustic waves and the short-lived, high-degree running waves are visible. The standing waves are visible as temporary enhancements of the amplitudes of the large-scale velocity field due to the stochastic superposition of the acoustic waves. We focus on the high-degree small-scale waves by suitable filtering in the Fourier domain. Investigating the propagation and excitation of f- and p {sub 1}-modes with wavenumbers k>1.4 Mm{sup -1}, we also find that exploding granules contribute to the excitation of solar p-modes in addition to the contribution of intergranular lanes.

  18. The Weather Radar Toolkit, National Oceanic and Atmospheric Administration (NOAA) National Climatic Data Center's support of interoperability and the Global Earth Observation System of Systems (GEOSS)

    NASA Astrophysics Data System (ADS)

    Ansari, S.; Del Greco, S.

    2006-12-01

    In February 2005, 61 countries around the World agreed on a 10 year plan to work towards building open systems for sharing geospatial data and services across different platforms worldwide. This system is known as the Global Earth Observation System of Systems (GEOSS). The objective of GEOSS focuses on easy access to environmental data and interoperability across different systems allowing participating countries to measure the "pulse" of the planet in an effort to advance society. In support of GEOSS goals, NOAA's National Climatic Data Center (NCDC) has developed radar visualization and data exporter tools in an open systems environment. The NCDC Weather Radar Toolkit (WRT) loads Weather Surveillance Radar 1988 Doppler (WSR-88D) volume scan (S-band) data, known as Level-II, and derived products, known as Level-III, into an Open Geospatial Consortium (OGC) compliant environment. The application is written entirely in Java and will run on any Java- supported platform including Windows, Macintosh and Linux/Unix. The application is launched via Java Web Start and runs on the client machine while accessing these data locally or remotely from the NCDC archive, NOAA FTP server or any URL or THREDDS Data Server. The WRT allows the data to be manipulated to create custom mosaics, composites and precipitation estimates. The WRT Viewer provides tools for custom data overlays, Web Map Service backgrounds, animations and basic filtering. The export of images and movies is provided in multiple formats. The WRT Data Exporter allows for data export in both vector polygon (Shapefile, Well-Known Text) and raster (GeoTIFF, ESRI Grid, VTK, NetCDF, GrADS) formats. By decoding the various Radar formats into the NetCDF Common Data Model, the exported NetCDF data becomes interoperable with existing software packages including THREDDS Data Server and the Integrated Data Viewer (IDV). The NCDC recently partnered with NOAA's National Severe Storms Lab (NSSL) to decode Sigmet C-band Doppler radar data providing the NCDC Viewer/Data Exporter the functionality to read C-Band. This also supports a bilateral agreement between the United States and Canada for data sharing and to support interoperability with the US WSR-88D and Environment Canada radar networks. In addition, the NCDC partnered with the University of Oklahoma to develop decoders to read a test bed of distributed X- band radars that are funded through the Collaborative Adaptive Sensing of the Atmosphere (CASA) project. The NCDC is also archiving the National Mosaic and Next Generation QPE (Q2) products from NSSL, which provide products such as three-dimensional reflectivity, composite reflectivity and precipitation estimates at a 1 km resolution. These three sources of Radar data are also supported in the WRT.

  19. Chemical Weathering Kinetics of Basalt on Venus

    NASA Technical Reports Server (NTRS)

    Fegley, Bruce, Jr.

    1997-01-01

    The purpose of this project was to experimentally measure the kinetics for chemical weathering reactions involving basalt on Venus. The thermochemical reactions being studied are important for the CO2 atmosphere-lithosphere cycle on Venus and for the atmosphere-surface reactions controlling the oxidation state of the surface of Venus. These reactions include the formation of carbonate and scapolite minerals, and the oxidation of Fe-bearing minerals. These experiments and calculations are important for interpreting results from the Pioneer Venus, Magellan, Galileo flyby, Venera, and Vega missions to Venus, for interpreting results from Earth-based telescopic observations, and for the design of new Discovery class (e.g., VESAT) and New Millennium missions to Venus such as geochemical landers making in situ elemental and mineralogical analyses, and orbiters, probes and balloons making spectroscopic observations of the sub-cloud atmosphere of Venus.

  20. Effect of Atmospheric CO2 Observations in Asia on the Optimization of Surface CO2 Flux

    NASA Astrophysics Data System (ADS)

    Kim, J.; Kim, H. M.; Cho, C. H.; Jacobson, A. R.; Sasakawa, M.; Machida, T.; Arshinov, M.; Fedoseev, N.

    2014-12-01

    Understanding sources and sinks of atmospheric CO2 is important to estimate the impact of CO2 on climate change and environment. Although surface CO2 sources and sinks in Asia affect the global carbon cycle considerably, the atmospheric CO2 observation network is sparse in Asia. Due to the sparse observations in Asia, the estimated surface CO2 fluxes in the Eurasian Boreal region differ considerably depending on the inversion systems used in the estimation. In this study, to investigate the effect of additional CO2 observations in the Eurasian Boreal region on the surface carbon flux analysis in the globe and Asia, two experiments using different observation data set were performed with CarbonTracker developed in NOAA. One experiment was conducted using a data set that includes additional observations of Siberian tower measurement data (Japan-Russia Siberian Tall Tower Inland Observation Network: JR-STATION) and data observed in China and India, and the other experiment was conducted using a data set without the above additional observations. Global balance of the source and sink of surface CO2 fluxes was maintained for both experiments with and without additional observations. While the magnitude of the optimized surface CO2 flux uptake in Siberia was decreased for the experiment with the additional observations, the magnitude of the optimized surface CO2 flux uptake in Western Europe and North America was increased. This result implies that the impact of the Siberian observation data is as large as other continuous measurements (e.g., tower measurements in North America). The average RMSE and bias of the model CO2 concentrations calculated using the optimized CO2 flux exhibited better agreement with the observed CO2 concentrations when the additional observations were used, which implies that the additional observations provide beneficial impact on the surface CO2 flux analysis in Asia.

  1. Weathering, Water, and Slope Aspect

    NASA Astrophysics Data System (ADS)

    Anderson, S. P.; Blum, A.; Lee, J.; Cowie, R. M.; Williams, M. W.; Frederick, Z. A.

    2009-12-01

    Aspect controls solar radiation to hillslopes: north facing slopes are more shaded (in the northern hemisphere), while south facing slopes are not. Here we explore how this simple topographic control on energy balance plays out in the architecture of the Critical Zone of a subwatershed in the Boulder Creek Critical Zone Observatory. Gordon Gulch catchment is within the upper montane forest of the Colorado Front Range, with mixed lodgepole-ponderosa pine forest cover. Because the valley trends E-W, hillslopes are either N-facing or S-facing. The annual snowpack is deeper and longer lasting on the lodgepole pine dominated N-facing slopes. Snow is thin or patchy on the open ponderosa pine dominated S-facing slopes. These shading and snowpack differences can be seen in soil temperatures and soil moisture. In a series of soil pits, we found mobile regolith was nearly twice as deep on the moist, N-facing slopes, and saprolite was more weathered in these locations. Saprolite was found at shallower depths on south-facing slopes, and was less weathered, and more competent. We entertain two hypotheses. The depth of mobile layer and degree of weathering of saprolite reflect either differences in material transport rates or differences in chemical weathering rates. In the case of material transport rate control, creep and bioturbation remove highly weathered saprolite, keeping fresher rock closer to the surface on the S-facing slopes. In the case of chemical weathering control, soil moisture maintains greater rates of chemical alteration of saprolite, and physical disruption by creep and bioturbation is minimal on N-facing slopes. The differences in weathering profile development in association with slope aspect provide a natural experiment to unravel competing effects of weathering and erosion on landscape development.

  2. Teaching through Trade Books: Weather Watchers

    NSDL National Science Digital Library

    Christine Royce

    2003-05-01

    In the past two months, students probably have heard weather-based sayings, such as "March comes in like a lion and goes out like a lamb" or "April showers bring May flowers." Throughout the ages, people have developed these and other sayings to try to predict what the weather holds for them, their locations, and their lifestyles. Even so, few people truly understand what causes the weather. Making weather observations with students provides opportunities to introduce meteorology while helping students develop their observation and data-collection skills. Activities for students in grades K-3 and 4-6 are provided.

  3. Observations of a shock and a recombination layer at the contact surface of Comet Halley

    NASA Technical Reports Server (NTRS)

    Goldstein, B. E.; Altwegg, K.; Balsiger, H.; Fuselier, S. A.; Ip, W.-H.

    1989-01-01

    Results are presented on observations in the vicinity of the contact surface of the Comet Halley, obtained by the Giotto ion mass spectrometer, with emphasis placed on two specific events observed in this region on the inbound pass. One was a burst of energized ions (about 20 eV) of 2-sec duration observed two seconds before the contact surface was encountered, which coincided with a pulse in magnetic field strength interpreted by Neubauer (1988) as a fast-mode shock traveling away from the contact surface. The second was a sharp spike in ion densities observed at the contact surface by the mass analyzer, centered approximately at the inner edge of the contact surface. This ion-density spike is interpreted as a boundary layer into which the radial ionospheric flow enters and piles up; the density increase is limited by recombination.

  4. Direct observation of surface diffusion of large organic molecules at metal surfaces: PVBA on Pd(110)

    NASA Astrophysics Data System (ADS)

    Weckesser, Jens; Barth, Johannes V.; Kern, Klaus

    1999-03-01

    The bonding and surface diffusion of 4-trans-2-(pyrid-4-yl-vinyl) benzoic acid (PVBA) on Pd(110) was investigated by variable temperature scanning tunneling microscopy at sample temperatures between 300 and 450 K. PVBA is a large organic molecule designed for nonlinear optics applications. At low coverages single PVBA molecules are randomly distributed at the surface where they bind diagonally to three neighboring Pd-rows, leading to four equivalent adsorption configurations. The "dog-bone" molecular structure could be resolved. The molecules' surface diffusion is strictly one-dimensional along the close-packed [11¯0]-direction of the surface Pd atomic rows and obeys an Arrhenius law with an activation barrier of 0.83±0.03 eV and an attempt frequency of 1010.3±0.4 s-1.

  5. Observations of Coupling between Surface Wind Stress and Sea Surface Temperature in the Eastern Tropical Pacific

    Microsoft Academic Search

    Dudley B. Chelton; Steven K. Esbensen; Michael G. Schlax; Nicolai Thum; Michael H. Freilich; Frank J. Wentz; Chelle L. Gentemann; Michael J. McPhaden; Paul S. Schopf

    2001-01-01

    Satellite measurements of surface wind stress from the QuikSCAT scatterometer and sea surface temperature (SST) from the Tropical Rainfall Measuring Mission Microwave Imager are analyzed for the three-month period 21 July-20 October 1999 to investigate ocean-atmosphere coupling in the eastern tropical Pacific. Oceanic tropical instability waves (TIWs) with periods of 20-40 days and wavelengths of 1000-2000 km perturb the SST

  6. Backyard Weather Station

    NSDL National Science Digital Library

    2014-09-18

    Students use their senses to describe what the weather is doing and predict what it might do next. After gaining a basic understanding of weather patterns, students act as state park engineers and design/build "backyard weather stations" to gather data to make actual weather forecasts.

  7. Yaquina Bay Weather & Tides

    E-print Network

    Wright, Dawn Jeannine

    Yaquina Bay Weather & Tides Clay Creech Phil Barbour #12;HMSC Weather Station #12;Temp-Humidity Sensor at Library #12;http://weather.hmsc.oregonstate.edu #12;#12;#12;#12;#12;#12;Archived Data is Available every 15 mins. #12;#12;A pyranometer measures solar radiation #12;#12;National Weather Service

  8. The Weather and Climate

    E-print Network

    Lovejoy, Shaun

    The Weather and Climate Emergent Laws and Multifractal Cascades Shaun LovEjoy and DaniEL SChErTzEr #12;2/15/12 DRAFT TABLE OF CONTENTS 1 DRAFT 1 The Weather And The Climate:2 Emergent Laws, weather, low frequency weather and the climate1 1.2.7 The scaling of the atmospheric boundary conditions2

  9. RHEED Observation on (001)ZnSe Surface: MBE Surface Phase Diagram and Kinetic Behavior of Zn And Se Adatoms

    Microsoft Academic Search

    Kazunori Menda; Ichiro Takayasu; Tetsuo Minato; Mitsuo Kawashima

    1987-01-01

    Reflection high-energy electron diffraction (RHEED) studies have been performed on epitaxial (001)ZnSe surfaces. The phase diagram on the surface grown by molecular beam epitaxy (MBE) was obtained by observing changes of RHEED patterns as a function of beam flux ratio and substrate temperature. The desorption time of Se atoms and the adsorption time of Zn atoms were also obtained by

  10. Comparison of Satellite-Derived and In-Situ Observations of Ice and Snow Surface Temperatures over Greenland

    NASA Technical Reports Server (NTRS)

    Hall, Dorothy K.; Box, Jason E.; Casey, Kimberly A.; Hook, Simon J.; Shuman, Christopher A.; Steffen, Konrad

    2008-01-01

    The most practical way to get a spatially broad and continuous measurements of the surface temperature in the data-sparse cryosphere is by satellite remote sensing. The uncertainties in satellite-derived LSTs must be understood to develop internally-consistent decade-scale land-surface temperature (LST) records needed for climate studies. In this work we assess satellite-derived "clear-sky" LST products from the Moderate Resolution Imaging Spectroradiometer (MODIS) and the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER), and LSTs derived from the Enhanced Thematic Mapper Plus (ETM+) over snow and ice on Greenland. When possible, we compare satellite-derived LSTs with in-situ air-temperature observations from Greenland Climate Network (GC-Net) automatic-weather stations (AWS). We find that MODIS, ASTER and ETM+ provide reliable and consistent LSTs under clear-sky conditions and relatively-flat terrain over snow and ice targets over a range of temperatures from -40 to 0 C. The satellite-derived LSTs agree within a relative RMS uncertainty of approx.0.5 C. The good agreement among the LSTs derived from the various satellite instruments is especially notable since different spectral channels and different retrieval algorithms are used to calculate LST from the raw satellite data. The AWS record in-situ data at a "point" while the satellite instruments record data over an area varying in size from: 57 X 57 m (ETM+), 90 X 90 m (ASTER), or to 1 X 1 km (MODIS). Surface topography and other factors contribute to variability of LST within a pixel, thus the AWS measurements may not be representative of the LST of the pixel. Without more information on the local spatial patterns of LST, the AWS LST cannot be considered valid ground truth for the satellite measurements, with RMS uncertainty approx.2 C. Despite the relatively large AWS-derived uncertainty, we find LST data are characterized by high accuracy but have uncertain absolute precision.

  11. Urban and land surface effects on the 30 July 2003 mesoscale convective system event observed in the southern Great Plains

    NASA Astrophysics Data System (ADS)

    Niyogi, Dev; Holt, Teddy; Zhong, Sharon; Pyle, Patrick C.; Basara, Jeffery

    2006-10-01

    The urban canopy of excess heat, water vapor, and roughness can affect the evolution of weather systems, as can land vegetative processes. High-resolution simulations were conducted using the Coupled Ocean/Atmosphere Mesoscale Prediction System (COAMPS®) to investigate the impact of urban and land vegetation processes on the prediction of the mesoscale convective system (MCS) observed on 30 July 2003 in the vicinity of Oklahoma City (OKC), Oklahoma. The control COAMPS model (hereinafter CONTROL) used the Noah land surface model (LSM) initialized with the Eta Data Assimilation System and incorporates an urban canopy parameterization (UCP). Experiments assessed the impact of land vegetative processes by (1) adding a canopy resistance scheme including photosynthesis (GEM) to the Noah LSM and (2) replacing the UCP with a simpler urban surface characterization of roughness, albedo, and moisture availability (NOUCP). The three sets of simulations showed different behaviors for the storm event. The CONTROL simulation propagated two storm cells through the OKC urban region. The NOUCP also resulted in two cells, although the convective intensity was weaker. The GEM simulation produced one storm cell west of the downtown region, whose intensity and timing were closer to the observed. To understand the relative roles of the urban and vegetation interaction processes, a factor separation experiment was performed. The urban model improved the ability to represent the MCS, and the enhanced representation of vegetation further improved the model performance. The enhanced performance may be attributed to better representation of the urban-rural heterogeneities and improved simulation of the moisture fluxes and upstream inflow boundaries.

  12. Observation of surface dispersive shock waves in a self-defocusing medium

    NASA Astrophysics Data System (ADS)

    Wang, Jing; Li, Juntao; Lu, Daquan; Guo, Qi; Hu, Wei

    2015-06-01

    We have theoretically and experimentally investigated surface dispersive shock waves (SDSWs) at the interface between a self-defocusing medium and a linear medium. We demonstrate that SDSWs can form when the linear refractive index of the self-defocusing medium is much greater than that of the linear medium, and the initial nonlinearity far outweighs diffraction. SDSWs have been observed at the interface between air and a weakly absorbing liquid when the power of the input beam far exceeds that needed to trap a surface dark soliton. We also observed the formation of SDSWs when an input beam was projected away from the interface, and observed these patterns at the curved surface.

  13. Forcing a Global, Offline Land Surface Modeling System with Observation-Based Fields

    NASA Technical Reports Server (NTRS)

    Rodell, Matthew; Houser, Paul R.; Jambor, U.; Gottschalck, J.; Radakovich, J.; Arsenault, K.; Meng, C.-J.; Mitchell, K. E.

    2002-01-01

    The Global Land Data Assimilation System (GLDAS) drives multiple uncoupled land surface models in order to produce optimal output fields of surface states in near-real time, globally, at 1/4 degree spatial resolution. These fields are then made available for coupled atmospheric model initialization and further research. One of the unique aspects of GLDAS is its ability to ingest both modeled and observation-derived forcing for running global scale land surface models. This paper compares results of runs forced by modeled and observed precipitation and shortwave radiation fields. Differences are examined and the impact of the observations on model skill is assessed.

  14. Weather Derivative Valuation

    NASA Astrophysics Data System (ADS)

    Jewson, Stephen; Brix, Anders

    2005-04-01

    Weather Derivative Valuation is the first book to cover all the meteorological, statistical, financial and mathematical issues that arise in the pricing and risk management of weather derivatives. There are chapters on meteorological data and data cleaning, the modelling and pricing of single weather derivatives, the modelling and valuation of portfolios, the use of weather and seasonal forecasts in the pricing of weather derivatives, arbitrage pricing for weather derivatives, risk management, and the modelling of temperature, wind and precipitation. Specific issues covered in detail include the analysis of uncertainty in weather derivative pricing, time-series modelling of daily temperatures, the creation and use of probabilistic meteorological forecasts and the derivation of the weather derivative version of the Black-Scholes equation of mathematical finance. Written by consultants who work within the weather derivative industry, this book is packed with practical information and theoretical insight into the world of weather derivative pricing.

  15. Preliminary analysis results of the Sea Surface Observation by a High Resolution Along-Track Interferometric SAR

    NASA Astrophysics Data System (ADS)

    Kojima, S.

    2013-12-01

    There are many requirements to detect the moving targets such as cars and ships in SAR images as well as to measure their speed. In particular, there are strongly requirements to detect ships and measure the ocean waves and the sea surface currents regardless of the time or the weather in the case of the ship accidents or the oil spill accidents because the rescue operation should be operated at the anytime. To satisfy these requirements, NICT developed the airborne along-track interferometric SAR (AT-InSAR) system in 2011. Kojima[1][2] carried out the preliminary experiments using a truck and ship to check its function and clarify its capability for the detection of the moving targets, and confirmed that its performance was satisfied with its specifications. The purpose of this study is to make clear the relationship between the phenomena on the sea surface such as the ocean waves and the velocity estimated from the AT-InSAR data, and the capability of the sea surface measurement by the AT-InSAR. In addition, the method to estimate wave directional spectra from AT-InSAR data is developed. The sea surface observation was carried out 3 km off the coast of Ooarai, the northeast of Tokyo, JAPAN on the 23th of August 2011. I observed the sea surface in the fine special resolution (0.3 m) and took a special average (1 m) to reduce noise. First of all, I estimated the wave velocity from the AT-InSAR images and calculated the 2D wave number spectra from it. And then, I estimated the directional wave spectra using the dispersion relation. As a result, it was clarified that the ocean waves could be measured by the AT-InSAR. In addition, it made clear that the bow waves and stern waves generated by a running ship could be detected by AT-InSAR. References [1] S. Kojima, T. Umehara, J. Uemoto, T. Kobayashi, M. Satake and S. Uratsuka, 'Development of Pi-SAR2 Along-Track Interferometric SAR System', IGARSS 2013, pp. 3159-3162, Aug. 2013. [2] S. Kojima, 'Evaluation of the Ship Detection by Dual Polarimetric Along-Track Interferometry', APSAR 2013, in printing, Sep. 2013. Acknowledgement I would like to acknowledge the support of Pi-SAR2 term for this experiment.

  16. Cloud-Dependent Surface Energy Budgets over the Ocean: Observation-Based and Reanalysis Estimates

    NASA Astrophysics Data System (ADS)

    Wong, S.; L'Ecuyer, T. S.; Fetzer, E. J.

    2014-12-01

    Regional balance of the atmospheric energy budget provides a stringent constraint to evaluate datasets of global energy budgets. Previous studies indicated that satellite-based and reanalysis estimates describe different heating rates in the atmosphere. Compared to the satellite-based heating rates, reanalyses (European Center for Medium Range Weather Forecast Interim, ERA-Interim, and Modern-Era Retrospective Analysis for Research and Applications, MERRA) have larger heating in the tropical convective regimes and smaller cooling in the subtropical subsidence regimes. Many of these discrepancies originate in cloudy regions where different estimation methods give different energy budgets. In this study, we investigate how different components of the surface energy budget depend on cloud properties in the atmosphere. We will also examine the dependence of discrepancies between reanalysis and the satellite-based surface energy budgets on cloud properties. Different satellite-based estimates, including Tropical Rainfall Measuring Mission (TRMM)-based surface shortwave and longwave heat fluxes, NASA Global Energy and Water Cycle Experiment surface energy budget (SRB) shortwave and longwave radiative heat fluxes, Goddard Satellite-based Surface Turbulent Flux (GSSTF)'s sensible and latent heat fluxes, and the objectively-analyzed air-sea fluxes (OAFlux), are collocated with cloud property measurements of Moderate Resolution Imaging Spectroradiometer (MODIS). MODIS cloud optical depth (COD) and cloud top pressure (CTP) are used to identify cloud types. Different components of surface energy budgets from the satellite-based estimates and the discrepancies from their reanalysis counterparts will be presented as functions of COD and CTP for selected regions that represent tropical convective and subtropical subsidence regimes.

  17. Weather monitoring and forecasting over eastern Attica (Greece) in the frame of FLIRE project

    NASA Astrophysics Data System (ADS)

    Kotroni, Vassiliki; Lagouvardos, Konstantinos; Chrysoulakis, Nektarios; Makropoulos, Christtos; Mimikou, Maria; Papathanasiou, Chrysoula; Poursanidis, Dimitris

    2015-04-01

    In the frame of FLIRE project a Decision Support System has been built with the aim to support decision making of Civil Protection Agencies and local stakeholders in the area of east Attica (Greece), in the cases of forest fires and floods. In this presentation we focus on a specific action that focuses on the provision of high resolution short-term weather forecasting data as well as of dense meteorological observations over the study area. Both weather forecasts and observations serve as an input in the Weather Information Management Tool (WIMT) of the Decision Support System. We focus on: (a) the description of the adopted strategy for setting-up the operational weather forecasting chain that provides the weather forecasts for the FLIRE project needs, (b) the presentation of the surface network station that provides real-time weather monitoring of the study area and (c) the strategy adopted for issuing smart alerts for thunderstorm forecasting based of real-time lightning observations as well as satellite observations.

  18. Chemical weathering fluxes from volcanic islands and the importance of groundwater: The Hawaiian example

    NASA Astrophysics Data System (ADS)

    Schopka, Herdis Helga; Derry, Louis A.

    2012-07-01

    We investigated the products and rates of chemical weathering on the Hawaiian Islands, sampling streams on Kaua'i and both streams and groundwater wells on the island of Hawai'i. Dissolved silica was used to investigate the flowpaths of water drained into streams. We found that flowpaths exert a major control on the observed chemical weathering rates. A strong link exists between the degree of landscape dissection and flowpaths of water through the landscape, with streams in undissected landscapes receiving water mainly from surface runoff and streams in highly dissected landscapes receiving a considerable fraction of their water from groundwater (springs and/or seepage). Total alkalinity in Hawaiian streams and groundwater is produced exclusively by silicate chemical weathering. We find that fluxes of total alkalinity (often called "CO2 consumption rate" in the geochemical literature), from the islands are lower than those observed in basaltic regions elsewhere. Groundwater is, overall, the major transport vector for products of chemical weathering from the Hawaiian Islands. On the youngest and largest island, submarine groundwater discharge (SGD) transports more than an order of magnitude more solutes to the ocean than surface water and on the youngest part of the youngest island, SGD is the only link between the terrestrial weathering system and the ocean. These results suggest that groundwater, and particularly SGD, needs to be included in geochemical weathering budgets of volcanic islands.

  19. Surface Reflectance of Mars Observed by CRISM-MRO: 1. Multi-angle Approach for Retrieval of Surface Reflectance from CRISM Observations (mars-reco)

    NASA Technical Reports Server (NTRS)

    Ceamanos, Xavier; Doute, S.; Fernando, J.; Pinet, P.; Lyapustin, A.

    2013-01-01

    This article addresses the correction for aerosol effects in near-simultaneous multiangle observations acquired by the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) aboard the Mars Reconnaissance Orbiter. In the targeted mode, CRISM senses the surface of Mars using 11 viewing angles, which allow it to provide unique information on the scattering properties of surface materials. In order to retrieve these data, however, appropriate strategies must be used to compensate the signal sensed by CRISM for aerosol contribution. This correction is particularly challenging as the photometric curve of these suspended particles is often correlated with the also anisotropic photometric curve of materials at the surface. This article puts forward an innovative radiative transfer based method named Multi-angle Approach for Retrieval of Surface Reflectance from CRISM Observations (MARS-ReCO). The proposed method retrieves photometric curves of surface materials in reflectance units after removing aerosol contribution. MARS-ReCO represents a substantial improvement regarding previous techniques as it takes into consideration the anisotropy of the surface, thus providing more realistic surface products. Furthermore, MARS-ReCO is fast and provides error bars on the retrieved surface reflectance. The validity and accuracy of MARS-ReCO is explored in a sensitivity analysis based on realistic synthetic data. According to experiments, MARS-ReCO provides accurate results (up to 10 reflectance error) under favorable acquisition conditions. In the companion article, photometric properties of Martian materials are retrieved using MARS-ReCO and validated using in situ measurements acquired during the Mars Exploration Rovers mission.

  20. Weathering of Thermal Control Coatings

    NASA Technical Reports Server (NTRS)

    Jaworske, Donald A.; Tuan, George C.; Westheimer, David T.; Peters, Wanda C.; Kauder, Lonny R.; Triolo, Jack J.

    2007-01-01

    Spacecraft radiators reject heat to their surroundings. Radiators can be deployable or mounted on the body of the spacecraft. NASA's Crew Exploration Vehicle is to use body mounted radiators. Coatings play an important role in heat rejection. The coatings provide the radiator surface with the desired optical properties of low solar absorptance and high infrared emittance. These specialized surfaces are applied to the radiator panel in a number of ways, including conventional spraying, plasma spraying, or as an applique. Not specifically designed for a weathering environment, little is known about the durability of conventional paints, coatings, and appliques upon exposure to weathering and subsequent exposure to solar wind and ultraviolet radiation exposure. In addition to maintaining their desired optical properties, the coatings must also continue to adhere to the underlying radiator panel. This is a challenge, as new composite radiator panels are being considered as replacements for the aluminum panels used previously. Various thermal control paints, coatings, and appliques were applied to aluminum and isocyanate ester composite coupons and were exposed for 30 days at the Atmospheric Exposure Site of the Kennedy Space Center s Beach Corrosion Facility for the purpose of identifying their durability to weathering. Selected coupons were subsequently exposed to simulated solar wind and vacuum ultraviolet radiation to identify the effect of a simulated space environment on the as-weathered surfaces. Optical properties and adhesion testing were used to document the durability of the paints and coatings. The purpose of this paper is to present the results of the weathering testing and to summarize the durability of several thermal control paints, coatings, and appliques to weathering and postweathering environments.

  1. Nowcasting extreme weather events over Greece

    NASA Astrophysics Data System (ADS)

    Katsafados, Petros; Nomikou, Vera; Mavromatidis, Elias; Papadopoulos, Anastasios; Lagouvardos, Konstantinos; Kotroni, Vassiliki

    2014-05-01

    Accurate and consistent very short-term prediction (nowcasting) of high-impact weather events can lead to significant improvement in warnings and advisories providing a direct impact on the risk management. To this end, an advanced mesoscale meteorological data assimilation tool, the Local Analysis and Prediction System (LAPS), has been implemented in order to serve as an early warning system. LAPS incorporates surface and upper air observations (METAR, SYNOP, satellite, soundings, radar, aircraft etc) into large-scale gridded data (as background fields) and produces high spatial and temporal resolution analysis fields and early forecasts. This study presents the performance of the LAPS system in describing two unusual events of hazardous weather conditions over Greece. The first case study is characterized by the passage of a cyclonic system accompanied with cold fronts over Southern Greece. Heavy downpour, lightning and flooding were the main characteristics of the storm that affected Athens metropolitan area on February 22nd 2013. In the second case study the passage of a cold front over SE Aegean Sea led in a destructive and deadly flash flooding that affected the Northern areas of Rhodes Island on November 22nd 2013. This second flash flood event was triggered by the extreme precipitation (almost 100 mm in 4 hours) and killed 4 people making it the deadliest ever for the area. For both case studies, the conventional numerical weather prediction models operating at various research institutes and universities provided a rather insufficient spatiotemporal estimation of the extreme precipitation. For these cases, the LAPS-based nowcasting procedure has been applied with and without the ingestion of high resolution remote sensed precipitation estimates. The LAPS outputs have been evaluated against independent observations obtained from a dense network of surface meteorological stations. Results indicate that LAPS outputs were better than those obtained from the conventional operational forecasts. Also, the use of the satellite information improved the LAPS-based hourly Quantitative Precipitation Estimates in terms of amount, timing and localization.

  2. The Surface Water and Ocean Topography Mission: Observing Terrestrial Surface Water and Oceanic Submesoscale Eddies

    Microsoft Academic Search

    Michael Durand; Lee-Lueng Fu; Dennis P. Lettenmaier; Douglas E. Alsdorf; Ernesto Rodriguez; Daniel Esteban-Fernandez

    2010-01-01

    The elevation of the ocean surface has been measured for over two decades from spaceborne altimeters. However, existing altimeter measurements are not adequate to characterize the dynamic variations of most inland water bodies, nor of ocean eddies at scales of less than about 100 km, notwithstanding that such eddies play a key role in ocean circulation and climate change. For

  3. Weather Camp 2012 "Weather and Climate All Around Us"

    E-print Network

    Farritor, Shane

    Weather Camp 2012 "Weather and Climate All Around Us" Are you interested in the weather? Come to Weather Camp at UNL What is Weather Camp? For more information Weather camp is a week long day camp for students who will be 11-14 years old at the time of the camp Most of the activities at Weather Camp 2012

  4. Observation of surface and bulk phase transitions in nematic liquid crystals.

    PubMed

    Boamfa, M I; Kim, M W; Maan, J C; Rasing, Th

    2003-01-01

    The behaviour of liquid crystal (LC) molecules near a surface is of both fundamental and technological interest: it gives rise to various surface phase-transition and wetting phenomena, and surface-induced ordering of the LC molecules is integral to the operation of LC displays. Here we report the observation of a pure isotropic-nematic (IN) surface phase transition-clearly separated from the bulk IN transition-in a nematic LC on a substrate. Differences in phase behaviour between surface and bulk are expected, but have hitherto proved difficult to distinguish, owing in part to the close proximity of their transition temperatures. We have overcome these difficulties by using a mixture of nematic LCs: small, surface-induced composition variations lead to complete separation of the surface and bulk transitions, which we then study independently as a function of substrate and applied magnetic field. We find the surface IN transition to be of first order on surfaces with a weak anchoring energy and continuous on surfaces with a strong anchoring. We show that the presence of high magnetic fields does not change the surface IN transition temperature, whereas the bulk IN transition temperature increases with field. We attribute this to the interaction energy between the surface and bulk phases, which is tuned by magnetic-field-induced order in the surface-wetting layer. PMID:12520297

  5. Aerosol loading in the Southeastern United States: reconciling surface and satellite observations

    E-print Network

    Ford, B.

    We investigate the seasonality in aerosols over the Southeastern United States using observations from several satellite instruments (MODIS, MISR, CALIOP) and surface network sites (IMPROVE, SEARCH, AERONET). We find that ...

  6. AN EXPERT SYSTEM FOR WEATHER PREDICTION BASED ON ANIMAL BEHAVIOUR

    Microsoft Academic Search

    Najat O. Alsaiari

    Long before technology was developed, people had to rely on observations, patterns and their experience to predict the weather. Observers reported that the animals have senses that warned them of weather by several hours or just seconds, which allowed animals and people to heed those warnings for the chance to find safety. People sometimes are out of touch with weather

  7. AN EXPERT SYSTEM FOR WEATHER PREDICTION BASED ON ANIMAL BEHAVIOUR

    Microsoft Academic Search

    Najat O. Alsaiari

    2012-01-01

    Long before technology was developed, people had to rely on observations, patterns and their experience to predict the weather. Observers reported that the animals have senses that warned them of weather by several hours or just seconds, which allowed animals and people to heed those warnings for the chance to find safety. People sometimes are out of touch with weather

  8. Impact of GOES satellites on the National Weather Service

    Microsoft Academic Search

    Elbert W. Friday

    1996-01-01

    The geostationary weather satellites are a critical component of the National Weather Service operations and on going nation wide modernization program. Geostationary satellites, because of their ability to constantly image the Earth, are important tools for observing severe weather such as hurricanes, severe thunderstorms, flash floods and winter storms. When satellite data are combined with other observing technologies such as

  9. Advances towards the operational validation of satellite sea surface skin temperature observations

    Microsoft Academic Search

    C. J. Donlon; W. J. Emery; I. S. Robinson

    1998-01-01

    Deploying infrared radiometers at sea is difficult due to the harsh environmental conditions often encountered and high costs associated with many sea-going radiometer systems. This has prevented the operational collection of a global in situ sea surface skin temperature (SSST) data set forcing many satellite validation exercises to rely on subsurface “bulk” sea surface temperature (BSST) observations. We describe a

  10. The Probability Distribution of Sea Surface Wind Speeds. Part I: Theory and SeaWinds Observations

    E-print Network

    Monahan, Adam Hugh

    The Probability Distribution of Sea Surface Wind Speeds. Part I: Theory and SeaWinds Observations expressions for the probability distribution of w in terms of the mean and standard deviation of the vector of the probability distribution of sea surface wind speeds play a central role in a number of problems in meteorology

  11. Dynamically balanced absolute sea level of the global ocean derived from near-surface velocity observations

    E-print Network

    temperature and salinity described in the World Ocean Atlas 2001 [Conkright et al., 2002] (WOA01), and assumesDynamically balanced absolute sea level of the global ocean derived from near-surface velocity distribution of the global ocean is computed for the first time from observations of near-surface velocity

  12. Meteorological Adjustment of Chicago, Illinois, Regional Surface Ozone Observations with investigation of Trends

    E-print Network

    Washington at Seattle, University of

    Meteorological Adjustment of Chicago, Illinois, Regional Surface Ozone Observations o r t S e r i e s NRCSE-TRS No. 025 #12;Meteorological Adjustment of Chicago, Illinois, Regional Peter Guttorp June 11, 1999 Abstract Meteorological adjustment of surface ozone records from 10 monitors

  13. OFFLINE EVALUATION OF SIX SURFACE LAYER PARAMETERIZATION SCHEMES AGAINST OBSERVATIONS AT THE ARM SGP SITE

    E-print Network

    OFFLINE EVALUATION OF SIX SURFACE LAYER PARAMETERIZATION SCHEMES AGAINST OBSERVATIONS AT THE ARM of surface fluxes collected by the DOE (Department of Energy) ARM (Atmospheric Radiation Measurement) program to quantify the uncertainty/discrepancy between the ARM measurements based on the EC (Eddy Correlation

  14. Observation of surface features on an active landslide, and implications for understanding its history of movement

    Microsoft Academic Search

    Mario Parise

    2003-01-01

    Surface features are produced as a result of internal deformation of active landslides, and are continuously created and destroyed by the movement. Observation of their presence and distribution, and surveying of their evolution may provide insights for the zonation of the mass movement in sectors characterized by different behaviour. The present study analyses and describes some example of surface features

  15. Satellite observations and estimates of surface flow in the northwestern Gulf of Mexico 

    E-print Network

    Barron, Charlie Nelms

    1992-01-01

    SATELLITE OBSERVATIONS AND ESTIMATES OF SURFACE FLOW IN THE NORTHWESTERN GULF OF MEXICO A Thesis by CHARLIE NELMS BARRON JR. Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements... for the degree of MASTER OF SCIENCE May 1992 Major Subject: Oceanography SATELLITE OBSERVATIONS AND ESTIMATES OF SURFACE FLOW IN THE NORTHWESTERN GULF OF MEXICO A Thesis by CHARLIE NELMS BARRON JR. Approved as to style and content by: Andrew C. Vastano...

  16. Observation of topological surface state quantum Hall effect in an intrinsic three-dimensional topological insulator

    NASA Astrophysics Data System (ADS)

    Xu, Yang; Miotkowski, Ireneusz; Liu, Chang; Tian, Jifa; Nam, Hyoungdo; Alidoust, Nasser; Hu, Jiuning; Shih, Chih-Kang; Hasan, M. Zahid; Chen, Yong P.

    2014-12-01

    A three-dimensional (3D) topological insulator (TI) is a quantum state of matter with a gapped insulating bulk yet a conducting surface hosting topologically protected gapless surface states. One of the most distinct electronic transport signatures predicted for such topological surface states (TSS) is a well-defined half-integer quantum Hall effect (QHE) in a magnetic field, where the surface Hall conductivities become quantized in units of (1/2)e2/h (e being the electron charge, h the Planck constant) concomitant with vanishing resistance. Here, we observe a well-developed QHE arising from TSS in an intrinsic TI of BiSbTeSe2. Our samples exhibit surface-dominated conduction even close to room temperature, whereas the bulk conduction is negligible. At low temperatures and high magnetic fields perpendicular to the top and bottom surfaces, we observe well-developed integer quantized Hall plateaux, where the two parallel surfaces each contribute a half-integer e2/h quantized Hall conductance, accompanied by vanishing longitudinal resistance. When the bottom surface is gated to match the top surface in carrier density, only odd integer QH plateaux are observed, representing a half-integer QHE of two degenerate Dirac gases. This system provides an excellent platform to pursue a plethora of exotic physics and novel device applications predicted for TIs, ranging from magnetic monopoles and Majorana particles to dissipationless electronics and fault-tolerant quantum computers.

  17. Global chemical weather forecasts for field campaign planning: predictions and observations of large-scale features during MINOS, CONTRACE, and INDOEX

    Microsoft Academic Search

    M. G. Lawrence; P. J. Rasch; R. von Kuhlmann; J. Williams; H. Fischer; M. de Reus; J. Lelieveld; P. J. Crutzen; M. Schultz; P. Stier; H. Huntrieser; J. Heland; A. Stohl; C. Forster; H. Elbern; H. Jakobs; R. R. Dickerson

    2003-01-01

    The first global tropospheric forecasts of O3 and its precursors have been used in the daily flight planning of field measurement campaigns. The 3-D chemistry-transport model MATCH-MPIC is driven by meteorological data from a weather center (NCEP) to produce daily 3-day forecasts of the global distributions of O3 and related gases, as well as regional CO tracers. This paper describes

  18. Global chemical weather forecasts for field campaign planning: predictions and observations of large-scale features during MINOS, CONTRACE, and INDOEX

    Microsoft Academic Search

    M. G. Lawrence; P. J. Rasch; R. von Kuhlmann; J. Williams; H. Fischer; M. de Reus; J. Lelieveld; P. J. Crutzen; M. Schultz; P. Stier; H. Huntrieser; J. Heland; A. Stohl; C. Forster; H. Elbern; H. Jakobs; R. R. Dickerson

    2002-01-01

    The first global tropospheric forecasts of O3 and its precursors have been used in the daily flight planning of field measurement campaigns. The 3-D chemistry-transport model MATCH-MPIC is driven by meteorological data from a weather center (NCEP) to produce daily 3-day forecasts of the global distributions of O3 and related gases, as well as regional CO tracers. This paper describes

  19. Weathering, Geomorphology and Climatic Variability in the Central Namib Desert

    Microsoft Academic Search

    Heather Viles; Andrew Goudie

    Weathering is an important component of geomorphological change in the Central Namib Desert. Previous studies have reported on the weathering role of salt and dissolution, allied with wind abrasion. However, many surface are covered by luxuriant lichen growths, fed by fog precipitation, whose weathering role has not been clarified. Here we present preliminary investigations of the role of lichens and

  20. Geoelectric investigations into sandstone moisture regimes: Implications for rock weathering and the deterioration of San Rock Art in the Golden Gate Reserve, South Africa

    NASA Astrophysics Data System (ADS)

    Mol, L.; Viles, H. A.

    2010-06-01

    The Clarens sandstone in the Golden Gate Reserve, South Africa, is the canvas for a collection of San (Bushmen) Rock Art, dating from Neolithic times until as recently as 150 years ago. This Rock Art is under threat from human interference but also, to a greater degree, from weathering processes on the rock surface. The dominant weathering processes occurring in the rock shelters which host the Rock Art are flaking and honeycombing. Two rock shelter sites in the Reserve have been investigated using electric resistivity tomography (ERT) and supportive methods for measuring surface moisture (Protimeter) and surface hardness (Equotip). These non-destructive techniques can be used in situ to assess the extent of weathering within a rock outcrop and are especially suited for investigations in sensitive areas such as Rock Art sites. Moisture movement has been mapped and related to the weathering processes observed on the surface. The aim of the study is to aid Rock Art conservation in the Golden Gate Reserve through a better understanding of the driving processes of surface weathering. The evidence shows that the extensive flaking and honeycombing found in the rock shelters is most likely caused by water pockets in the near-surface zone, which are replenished through internal moisture transport, driving the superficial weathering processes. These weathering processes pose a significant problem: Rock Art in the Golden Gate Reserve shows severe deterioration due to flaking. Conservation strategies should therefore take internal processes into account as much as their superficial expression.

  1. AWE: Aviation Weather Data Visualization Environment

    NASA Technical Reports Server (NTRS)

    Spirkovska, Lilly; Lodha, Suresh K.

    2000-01-01

    The two official sources for aviation weather reports both provide weather information to a pilot in a textual format. A number of systems have recently become available to help pilots with the visualization task by providing much of the data graphically. However, two types of aviation weather data are still not being presented graphically. These are airport-specific current weather reports (known as meteorological observations, or METARs) and forecast weather reports (known as terminal area forecasts, or TAFs). Our system, Aviation Weather Environment (AWE), presents intuitive graphical displays for both METARs and TAFs, as well as winds aloft forecasts. We start with a computer-generated textual aviation weather briefing. We map this briefing onto a cartographic grid specific to the pilot's area of interest. The pilot is able to obtain aviation-specific weather for the entire area or for his specific route. The route, altitude, true airspeed, and proposed departure time can each be modified in AWE. Integral visual display of these three elements of weather reports makes AWE a useful planning tool, as well as a weather briefing tool.

  2. Weather Modification A Theoretician's Viewpoint.

    NASA Astrophysics Data System (ADS)

    Young, Kenneth C.

    1996-11-01

    Early progress in weather modification is attributed to a healthy interaction between theory and experiment. During the 1970s, a divergence of approaches took place. A "theoretical/experimental" approach, exemplified by the Cascade Project, focused on testing scientific hypotheses; an "observational/experimental" approach, exemplified by the Colorado River Basin Pilot Project, sought to enhance understanding of the seeding process through more detailed observations.The theoretical/experimental school soon came to focus almost exclusively on natural cloud processes, leaving the field of weather modification nearly devoid of a theoretical component. It is suggested that this theoretical component is necessary to revitalize the field of weather modification.Key questions are addressed. These include 1) identification of clouds that are amenable to seeding; 2) glaciogenic versus hygroscopic seeding; 3) optimizing critical seeding variables, such as seed particle concentration for glaciogenic seeding and seed particle size for hygroscopic seeding; and 4) seeding for hail suppression.

  3. Ion Irradiation Experiments on the Murchison CM2 Carbonaceous Chondrite: Simulating Space Weathering of Primitive Asteroids

    NASA Technical Reports Server (NTRS)

    Keller, L. P.; Christoffersen, R.; Dukes, C. A.; Baragiola, R. A.; Rahman, Z.

    2015-01-01

    Remote sensing observations show that space weathering processes affect all airless bodies in the Solar System to some degree. Sample analyses and lab experiments provide insights into the chemical, spectroscopic and mineralogic effects of space weathering and aid in the interpretation of remote- sensing data. For example, analyses of particles returned from the S-type asteroid Itokawa by the Hayabusa mission revealed that space-weathering on that body was dominated by interactions with the solar wind acting on LL ordinary chondrite-like materials [1, 2]. Understanding and predicting how the surface regoliths of primitive carbonaceous asteroids respond to space weathering processes is important for future sample return missions (Hayabusa 2 and OSIRIS-REx) that are targeting objects of this type. Here, we report the results of our preliminary ion irradiation experiments on a hydrated carbonaceous chondrite with emphasis on microstructural and infrared spectral changes.

  4. Reconstructing the weather on Mars at the time of the MERs and Beagle 2 landings

    E-print Network

    Mendillo, Michael

    Reconstructing the weather on Mars at the time of the MERs and Beagle 2 landings L. Montabone,1,2 S of the atmosphere on Mars from the surface to 120 km altitude at the time of the landing of the two NASA Mars of temperature and dust opacity observations from the Thermal Emission Spectrometer aboard the Mars Global

  5. Effect of Microbial Weathering on Carbonate Rocks

    NASA Astrophysics Data System (ADS)

    LIAN, Bin; CHEN, Ye; ZHU, Lijun; YANG, Ruidong

    The interaction between microorganisms and minerals can facilitate the process of exogenic biogeochemical reaction, which is one of the important research contents in exogenic geochemistry. Microbes and their geological effects were summarized, and a variety of microbial weathering phenomena toward carbonate rocks, especially on different microcosmic scales, were analyzed. Weathering products and mechanisms of carbonate rocks by microbes were also expounded. The authors put forward four microbial weathering mechanisms of carbonate rocks: (1) microorganisms grow on rock surface or in crevices, resulting in bio-corrosion, bio-erosion, and boring, and accelerate rock decomposition and weathering; (2) boring meshes produced by microbial colony could increase the efficient superficial area of chemical denudation of rocks and could lead to the intensification of rock surface weathering to promote mechanical erosion, and the microbial destruction and loosing of cementation structure of rock particles would also accelerate the decomposition of mineral particles; (3) rock weathering can be intensified by the effects of microbial water-keeping, acidification of organic acids secreted by microorganisms, and the release of CO 2 induced by microbial respiration onto rock surface; (4) microorganisms obtain nutrition from rock surface to produce complicated organic ligands and promote the release of mineral elements in the growing process of microorganisms. Finally, how to carry out studies on the microbial weathering of carbonate rocks was proposed. The authors suggest to comprehensively exploit local low-grade mineral resources, which contain potassium and phosphate, and accelerate soil formation and evolution in karst regions by using microbial technology.

  6. ICESat Observations of Inland Surface Water Stage, Slope, and Extent: a New Method for Hydrologic Monitoring

    NASA Technical Reports Server (NTRS)

    Harding, David J.; Jasinski, Michael F.

    2004-01-01

    River discharge and changes in lake, reservoir and wetland water storage are critical terms in the global surface water balance, yet they are poorly observed globally and the prospects for adequate observations from in-situ networks are poor (Alsdorf et al., 2003). The NASA-sponsored Surface Water Working Group has established a framework for advancing satellite observations of river discharge and water storage changes which focuses on obtaining measurements of water surface height (stage), slope, and extent. Satellite laser altimetry, which can achieve centimeter-level elevation precision for single, small laser footprints, provides a method to obtain these inland water parameters and contribute to global water balance monitoring. Since its launch in January, 2003 the Ice, Cloud, and land Elevation Satellite (ICESat), a NASA Earth Observing System mission, has achieved over 540 million laser pulse observations of ice sheet, ocean surface, land topography, and inland water elevations and cloud and aerosol height distributions. By recording the laser backscatter from 80 m diameter footprints spaced 175 m along track, ICESat acquires globally-distributed elevation profiles, using a 1064 nm laser altimeter channel, and cloud and aerosol profiles, using a 532 nm atmospheric lidar channel. The ICESat mission has demonstrated the following laser altimeter capabilities relevant to observations of inland water: (1) elevation measurements with a precision of 2 to 3 cm for flat surfaces, suitable for detecting river surface slopes along long river reaches or between multiple crossings of a meandering river channel, (2) from the laser backscatter waveform, detection of water surface elevations beneath vegetation canopies, suitable for measuring water stage in flooded forests, (3) single pulse absolute elevation accuracy of about 50 cm (1 sigma) for 1 degree sloped surfaces, with calibration work in progress indicating that a final accuracy of about 12 cm (1 sigma) will be achieved for clear atmosphere conditions, suitable for detection of stage changes through time, (4) ability to precisely point the spacecraft so as to position the laser profile on the Earth the surface with a cross-track accuracy of 50 m (1 sigma), enabling small water bodies and specific locations to be targeted and re-observed through time, (5) adequate signal levels from specular water surfaces up to 5 degrees off-nadir, enabling complete global access to any location on the Earth's surface from the ICESat repeat orbit by off-nadir pointing, and (6) day and night operation with successful laser ranging to the Earth's surface through thin to moderate cloud cover, enabling more frequent measurements than can be achieved by passive optical sensors. Here we illustrate these capabilities by showing ICESat observations through time for selected river and lake locations.

  7. Evaluating the two-source energy balance model using local thermal and surface flux observations in a strongly advective irrigated agricultural area

    NASA Astrophysics Data System (ADS)

    Kustas, William P.; Alfieri, Joseph G.; Anderson, Martha C.; Colaizzi, Paul D.; Prueger, John H.; Evett, Steven R.; Neale, Christopher M. U.; French, Andrew N.; Hipps, Lawrence E.; Chávez, José L.; Copeland, Karen S.; Howell, Terry A.

    2012-12-01

    Application and validation of many thermal remote sensing-based energy balance models involve the use of local meteorological inputs of incoming solar radiation, wind speed and air temperature as well as accurate land surface temperature (LST), vegetation cover and surface flux measurements. For operational applications at large scales, such local information is not routinely available. In addition, the uncertainty in LST estimates can be several degrees due to sensor calibration issues, atmospheric effects and spatial variations in surface emissivity. Time differencing techniques using multi-temporal thermal remote sensing observations have been developed to reduce errors associated with deriving the surface-air temperature gradient, particularly in complex landscapes. The Dual-Temperature-Difference (DTD) method addresses these issues by utilizing the Two-Source Energy Balance (TSEB) model of Norman et al. (1995) [1], and is a relatively simple scheme requiring meteorological input from standard synoptic weather station networks or mesoscale modeling. A comparison of the TSEB and DTD schemes is performed using LST and flux observations from eddy covariance (EC) flux towers and large weighing lysimeters (LYs) in irrigated cotton fields collected during BEAREX08, a large-scale field experiment conducted in the semi-arid climate of the Texas High Plains as described by Evett et al. (2012) [2]. Model output of the energy fluxes (i.e., net radiation, soil heat flux, sensible and latent heat flux) generated with DTD and TSEB using local and remote meteorological observations are compared with EC and LY observations. The DTD method is found to be significantly more robust in flux estimation compared to the TSEB using the remote meteorological observations. However, discrepancies between model and measured fluxes are also found to be significantly affected by the local inputs of LST and vegetation cover and the representativeness of the remote sensing observations with the local flux measurement footprint.

  8. The Weather Man

    NSDL National Science Digital Library

    Mrs. Emma Grasser

    2012-09-27

    This project is designed to let you be "The Weather Man" and control the weather through simulation, and hands on experience, followed by guided questioning and resource exploration. Form groups of three. Explore the following simulation: Weather Maker Simulator Use the simulation to answer the following questions on paper. 1. How does humility play a role in weather? How does more or less change weather? 2. What is water vapor? Where does it come from? 3. What happens when the weather drops below zero degrees? ...

  9. Science Sampler: Weather RATS

    NSDL National Science Digital Library

    Mary Taft

    2006-02-01

    Weather RATS, or Weather Research and Tracking Systems, is a collaborative effort among a national network of K-12 students, their teachers, wireless weather stations, internet data sharing, and professional engineers and meteorologists. Weather Rats is a new way to teach K-12 science and technology by tracking and comparing weather data from schools in Massachusetts, Arizona, Oklahoma, and Puerto Rico. In addition, it is hoped through this enriching project that Weather RATS will inspire many more students, especially girls and minorities, to pursue careers in science and engineering as a result of this project.

  10. Pilot weather advisor

    NASA Technical Reports Server (NTRS)

    Kilgore, W. A.; Seth, S.; Crabill, N. L.; Shipley, S. T.; Graffman, I.; Oneill, J.

    1992-01-01

    The results of the work performed by ViGYAN, Inc., to demonstrate the Pilot Weather Advisor cockpit weather data system using a broadcast satellite communication system are presented. The Pilot Weather Advisor demonstrated that the technical problems involved with transmitting significant amount of weather data to an aircraft in-flight or on-the-ground via satellite are solvable with today's technology. The Pilot Weather Advisor appears to be a viable solution for providing accurate and timely weather information for general aviation aircraft.

  11. Interactive Weather Information Network

    NSDL National Science Digital Library

    Offered by the National Oceanic and Atmospheric Administration (NOAA), the Interactive Weather Information Network (IWIN) is a collection of interactive weather maps and satellite images that is updated every five seconds. Visitors can see cloud cover animation loops, NEXRAD Radar images of precipitation, a map of all current weather fronts, and an interactive national map to see information about any particular state. Other information on the site includes a listing of any active weather warnings, a link for world weather data, and more, making this a must-see site for all those users interested in the most current weather happenings anywhere.

  12. Weather and Precipitation

    NSDL National Science Digital Library

    Ms. Jones

    2012-04-12

    How are different types of weather common in our everyday life? How can we use what we know about weather to go about everyday activities? First, use the Weather Chart to write down what you learn from each website. Then, go to Weather Information Website #1 and click on "What's the Weather?" to dress the bear for the day. Make sure you write it down on your graphic organizer. Next, go to Weather Information Website #3 and explore at least 5(clouds, thunderstorms, winter storms, etc.) of ...

  13. Graphical tools for TV weather presentation

    NASA Astrophysics Data System (ADS)

    Najman, M.

    2010-09-01

    Contemporary meteorology and its media presentation faces in my opinion following key tasks: - Delivering the meteorological information to the end user/spectator in understandable and modern fashion, which follows industry standard of video output (HD, 16:9) - Besides weather icons show also the outputs of numerical weather prediction models, climatological data, satellite and radar images, observed weather as actual as possible. - Does not compromise the accuracy of presented data. - Ability to prepare and adjust the weather show according to actual synoptic situtation. - Ability to refocus and completely adjust the weather show to actual extreme weather events. - Ground map resolution weather data presentation need to be at least 20 m/pixel to be able to follow the numerical weather prediction model resolution. - Ability to switch between different numerical weather prediction models each day, each show or even in the middle of one weather show. - The graphical weather software need to be flexible and fast. The graphical changes nee to be implementable and airable within minutes before the show or even live. These tasks are so demanding and the usual original approach of custom graphics could not deal with it. It was not able to change the show every day, the shows were static and identical day after day. To change the content of the weather show daily was costly and most of the time impossible with the usual approach. The development in this area is fast though and there are several different options for weather predicting organisations such as national meteorological offices and private meteorological companies to solve this problem. What are the ways to solve it? What are the limitations and advantages of contemporary graphical tools for meteorologists? All these questions will be answered.

  14. Image processing for weather satellite cloud segmentation

    Microsoft Academic Search

    I. J. H. Leung; J. E. Jordan

    1995-01-01

    Image segmentation of weather satellite imagery is an important first step in an automated weather forecasting system. Accurate cloud extraction is also important in the determination of solar radiative transfer in atmospheric research, where satellite observations are used as inputs to global climate models to predict climatic change. Most of the current cloud extraction algorithms tend to be quite complicated

  15. Redesigning a Graphic Weather Display for Pilots

    Microsoft Academic Search

    David OHare; Neil Stenhouse

    2008-01-01

    Before embarking on a flight, pilots need to acquire information about the actual and forecast weather conditions. Concerns have been raised about the traditional coded format used to provide this information. Software developers have recently provided tools for generating both plain-English and graphical versions of these coded weather observations. We show how we successfully applied a number of ergonomic display

  16. Internet Weather Links: Weather and Weather Related Lesson Plans

    NSDL National Science Digital Library

    The Internet Weather Links is a collection of lesson plans provided by the Utah Education Network's Weather Report Web site. The activities are organized by grade level from kindergarten to fourth grade and include such topics as Sunny Colors, Weather in a Box, Changes Due to Freezing, and Geological Features. Each lesson is well organized with explanations of its objectives, intended learning outcomes, and instructional procedures. Downloadable documents, related links, extensions to the lesson, and even rating systems for teachers are also provided, making it a great resource especially for use with younger students.

  17. Bayesian Modeling of Perceived Surface Slant from Actively-Generated and Passively-Observed Optic Flow

    Microsoft Academic Search

    Corrado Caudek; Carlo Fantoni; Fulvio Domini; Hans P. Op. de Beeck

    2011-01-01

    We measured perceived depth from the optic flow (a) when showing a stationary physical or virtual object to observers who moved their head at a normal or slower speed, and (b) when simulating the same optic flow on a computer and presenting it to stationary observers. Our results show that perceived surface slant is systematically distorted, for both the active

  18. Using microwave observations to estimate land surface temperature during cloudy conditions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Land surface temperature (LST), a key ingredient for physically-based retrieval algorithms of hydrological states and fluxes, remains a poorly constrained parameter for global scale studies. The main two observational methods to remotely measure T are based on thermal infrared (TIR) observations and...

  19. Observation of Star-Shaped Surface Gravity Waves Jean Rajchenbach1

    E-print Network

    Paris-Sud XI, Université de

    Observation of Star-Shaped Surface Gravity Waves Jean Rajchenbach1 , Didier Clamond2 and Alphonse of standing gravity waves of large amplitude, having alternatively the shape of a star and of a polygon between three gravity waves can be envisaged to trigger the observed symmetry breaking, although more

  20. Plutonium-238 observations as a test of modeled transport and surface deposition of meteoric smoke particles

    E-print Network

    Chipperfield, Martyn

    Plutonium-238 observations as a test of modeled transport and surface deposition of meteoric smoke chemistry-climate model (CCM) to simulate the transport and deposition of plutonium- 238 oxide nanoparticles. P. Chipperfield, and J. M. C. Plane (2013), Plutonium-238 observations as a test of modeled

  1. Weather Camp 2012: Weather and Climate All Around Us Are you interested in the weather?

    E-print Network

    Farritor, Shane

    Weather Camp 2012: Weather and Climate All Around Us Are you interested in the weather? Come to Weather Camp at UNL! What is Weather Camp? For more information Weather camp is a week-long day camp for students who will be 11-14 years old at the time of the camp. Most of the activities at Weather Camp 2012

  2. Mountain Weather

    NSDL National Science Digital Library

    In this interactive resource students slide a bar across the screen and view the steps in the water cycle as a water-laden air mass hits a mountain range. They see how clouds and precipitation form as the air mass ascends the windward side of the mountain, and observe the rain shadow created on the leeward side by the descending, warmed, and moisture-depleted air.

  3. The Wave Glider°: A New Autonomous Surface Vehicle to Augment MBARI's Growing Fleet of Ocean Observing Systems

    NASA Astrophysics Data System (ADS)

    Tougher, B. B.

    2011-12-01

    Monterey Bay Aquarium Research Institute's (MBARI) evolving fleet of ocean observing systems has made it possible to collect information and data about a wide variety of ocean parameters, enabling researchers to better understand marine ecosystems. In collaboration with Liquid Robotics Inc, the designer of the Wave Glider autonomous surface vehicle (ASV), MBARI is adding a new capability to its suite of ocean observing tools. This new technology will augment MBARI research programs that use satellites, ships, moorings, drifters, autonomous underwater vehicles (AUVs) and remotely operated vehicles (ROVs) to improve data collection of temporally and spatially variable oceanographic features. The Wave Glider ASV derives its propulsion from wave energy, while sensors and communications are powered through the use of two solar panels and batteries, enabling it to remain at sea indefinitely. Wave Gliders are remotely controlled via real-time Iridium burst communications, which also permit real-time data telemetry. MBARI has developed Ocean Acidification (OA) moorings to continuously monitor the chemical and physical changes occurring in the ocean as a result of increased levels of atmospheric carbon dioxide (CO2). The moorings are spatially restricted by being anchored to the seafloor, so during the summer of 2011 the ocean acidification sensor suite designed for moorings was integrated into a Wave Glider ASV to increase both temporal and spatial ocean observation capabilities. The OA sensor package enables the measurement of parameters essential to better understanding the changing acidity of the ocean, specifically pCO2, pH, oxygen, salinity and temperature. The Wave Glider will also be equipped with a meteorological sensor suite that will measure air temperature, air pressure, and wind speed and direction. The OA sensor integration into a Wave Glider was part of MBARI's 2011 summer internship program. This project involved designing a new layout for the OA sensors within a Wave Glider aft payload dry box. The Wave Glider OA sensor suite includes the addition of a pCO2 standard tank not included within the current OA moorings. Communication links between MBARI electronics and Liquid Robotics Control and Communications were successfully established in the laboratory, however further steps to fully integrate and test the OA system into a Wave Glider ASV are still needed. In the future these ASVs will provide platforms for additional surface and subsurface instrumentation, particularly with MBARI's upcoming Controlled, Agile, and Novel, Observing Network (CANON) projects. The integration of the OA sensor package into a Wave Glider ASV will make it possible to continuously monitor the marine environment during adverse weather conditions which are often difficult to document but scientifically important.

  4. Modeled and observed atmospheric radiation balance during the West African dry season: Role of mineral dust, biomass burning aerosol, and surface albedo

    NASA Astrophysics Data System (ADS)

    Milton, S. F.; Greed, G.; Brooks, M. E.; Haywood, J.; Johnson, B.; Allan, R. P.; Slingo, A.; Grey, W. M. F.

    2008-12-01

    The global radiation balance of the atmosphere is still poorly observed, particularly at the surface. We investigate the observed radiation balance at (1) the surface using the ARM Mobile Facility in Niamey, Niger, and (2) the top of the atmosphere (TOA) over West Africa using data from the Geostationary Earth Radiation Budget (GERB) instrument on board Meteosat-8. Observed radiative fluxes are compared with predictions from the global numerical weather prediction (NWP) version of the Met Office Unified Model (MetUM). The evaluation points to major shortcomings in the NWP model's radiative fluxes during the dry season (December 2005 to April 2006) arising from (1) a lack of absorbing aerosol in the model (mineral dust and biomass burning aerosol) and (2) a poor specification of the surface albedo. A case study of the major Saharan dust outbreak of 6-12 March 2006 is used to evaluate a parameterization of mineral dust for use in the NWP models. The model shows good predictability of the large-scale flow out to 4-5 days with the dust parameterization providing reasonable dust uplift, spatial distribution, and temporal evolution for this strongly forced dust event. The direct radiative impact of the dust reduces net downward shortwave (SW) flux at the surface (TOA) by a maximum of 200 W m-2 (150 W m-2), with a SW heating of the atmospheric column. The impacts of dust on terrestrial radiation are smaller. Comparisons of TOA (surface) radiation balance with GERB (ARM) show the "dusty" forecasts reduce biases in the radiative fluxes and improve surface temperatures and vertical thermodynamic structure.

  5. Basalt weathering in an Arctic Mars-analog site

    NASA Astrophysics Data System (ADS)

    Yesavage, Tiffany; Thompson, Aaron; Hausrath, Elisabeth M.; Brantley, Susan L.

    2015-07-01

    The martian surface has undergone chemical and physical weathering in the past, and these processes may continue intermittently today. To explore whether martian rocks are likely to retain features indicative of weathering, we investigated how basaltic material weathers on Earth. Specifically, we investigated weathering of a Quaternary-aged basaltic flow at the Sverrefjell volcano in Svalbard, above the Arctic Circle. This flow weathered since deglaciation under cold, dry (<400 mm/yr) conditions. We analyzed a ?75-cm core of regolith for chemical loss and then characterized the mineralogical and morphological properties using electron microscopy (EM), X-ray diffraction (XRD), infrared (IR) spectroscopy and selective chemical dissolution. In addition, we ran colloidal dispersion, wetting/drying, and freeze/thaw experiments. In the regolith, we observed concentrations of short-range ordered (SRO) phases similar to those observed in warmer, wetter volcanic ash soils. IR and EM analyses of the clay-sized fraction were consistent with allophane as the predominant secondary phase. Selective chemical extractions targeting SRO phases indicated lower Al/Si ratios than those observed in volcanic soils reported in warmer localities, which we attribute to Si-rich allophane and/or abundant Si-rich rock coatings. The oxic circumneutral-pH colloidal dispersion experiments mobilized Al, Fe and Ti primarily as 260-415 nm particles and Ca, Mg and Na as solutes. Si was lost both in the colloidal and dissolved forms. Dispersed colloids likely contain allophane and ferrihydrite. Under anoxic conditions, dissolution of Fe oxide cements also released fines. The experiments help to explain elemental loss from the clay-sized regolith fraction at Svalbard: observed depletions in Ca, K, Mg and Na were likely due to solute loss, while particle-reactive Al, Fe, Si and Ti were mostly retained. Wetting/drying was observed to be as effective as freeze/thaw in driving material loss. It is thus possible that cyclic adsorption of water onto basaltic rocks in this dry climate may result in high physical spalling rates that in turn promote chemical leaching. Many observations at Sverrefjell are similar to inferences from Mars: the presence of SRO phases, Si-rich coatings, and/or Si-rich allophane, as well as the persistence of olivine. Given these similarities, it is inferred that Sverrefjell volcano is a good analog for martian weathering and that other processes operating at Sverrefjell may also have occurred on Mars, including Na leaching, surface spalling, and precipitation of Si-rich layers. Such processes could have occurred on Mars wherever basalts were exposed to water at circumneutral pH for thousands to tens of thousands of years.

  6. New Observations of C-band Brightness Temperatures and Ocean Surface Wind Speed and Rain Rate From the Hurricane Imaging Radiometer (HIRAD)

    NASA Technical Reports Server (NTRS)

    Miller, Timothy L.; James, M. W.; Roberts, J. B.; Buckley, C. D.; Biswas, S.; May, C.; Ruf, C. S.; Uhlhorn, E. W.; Atlas, R.; Black, P.; Albers, Cerese

    2012-01-01

    HIRAD flew on the WB-57 during NASA's GRIP (Genesis and Rapid Intensification Processes) campaign in August September of 2010. HIRAD is a new C-band radiometer using a synthetic thinned array radiometer (STAR) technology to obtain cross-track resolution of approximately 3 degrees, out to approximately 60 degrees to each side of nadir. By obtaining measurements of emissions at 4, 5, 6, and 6.6 GHz, observations of ocean surface wind speed and rain rate can be retrieved. This technique has been used for many years by precursor instruments, including the Stepped Frequency Microwave Radiometer (SFMR), which has been flying on the NOAA and USAF hurricane reconnaissance aircraft for several years to obtain observations within a single footprint at nadir angle. Results from the flights during the GRIP campaign will be shown, including images of brightness temperatures, wind speed, and rain rate. Comparisons will be made with observations from other instruments on the GRIP campaign, for which HIRAD observations are either directly comparable or are complementary. Features such as storm eye and eyewall, location of storm wind and rain maxima, and indications of dynamical features such as the merging of a weaker outer wind/rain maximum with the main vortex may be seen in the data. Potential impacts on operational ocean surface wind analyses and on numerical weather forecasts will also be discussed.

  7. Intelligent weather agent for aircraft severe weather avoidance

    E-print Network

    Bokadia, Sangeeta

    2002-01-01

    avoidance capability has increased. In this thesis, an intelligent weather agent is developed for general aviation aircraft. Using a radar image from an onboard weather radar, the intelligent weather agent determines the safest path around severe weather...

  8. Assimilation of Freeze - Thaw Observations into the NASA Catchment Land Surface Model

    NASA Technical Reports Server (NTRS)

    Farhadi, Leila; Reichle, Rolf H.; DeLannoy, Gabrielle J. M.; Kimball, John S.

    2014-01-01

    The land surface freeze-thaw (F-T) state plays a key role in the hydrological and carbon cycles and thus affects water and energy exchanges and vegetation productivity at the land surface. In this study, we developed an F-T assimilation algorithm for the NASA Goddard Earth Observing System, version 5 (GEOS-5) modeling and assimilation framework. The algorithm includes a newly developed observation operator that diagnoses the landscape F-T state in the GEOS-5 Catchment land surface model. The F-T analysis is a rule-based approach that adjusts Catchment model state variables in response to binary F-T observations, while also considering forecast and observation errors. A regional observing system simulation experiment was conducted using synthetically generated F-T observations. The assimilation of perfect (error-free) F-T observations reduced the root-mean-square errors (RMSE) of surface temperature and soil temperature by 0.206 C and 0.061 C, respectively, when compared to model estimates (equivalent to a relative RMSE reduction of 6.7 percent and 3.1 percent, respectively). For a maximum classification error (CEmax) of 10 percent in the synthetic F-T observations, the F-T assimilation reduced the RMSE of surface temperature and soil temperature by 0.178 C and 0.036 C, respectively. For CEmax=20 percent, the F-T assimilation still reduces the RMSE of model surface temperature estimates by 0.149 C but yields no improvement over the model soil temperature estimates. The F-T assimilation scheme is being developed to exploit planned operational F-T products from the NASA Soil Moisture Active Passive (SMAP) mission.

  9. Winter Weather: Hypothermia

    MedlinePLUS

    ... Health Matters What's New Preparation & Planning Disasters & Severe Weather Earthquakes Extreme Heat Floods Hurricanes Landslides Tornadoes Tsunamis ... be successfully resuscitated. More Information: Frostbite Disasters & Severe Weather ... Heat Floods Hurricanes Landslides Tornadoes Tsunamis ...

  10. Winter Weather: Indoor Safety

    MedlinePLUS

    ... Health Matters What's New Preparation & Planning Disasters & Severe Weather Earthquakes Extreme Heat Floods Hurricanes Landslides Tornadoes Tsunamis ... Outdoor Safety Winter PSAs and Podcasts Disasters & Severe Weather Earthquakes Extreme Heat Floods Hurricanes Landslides Tornadoes Tsunamis ...

  11. In Depth Winter Weather

    NSDL National Science Digital Library

    2012-01-01

    Winter Weather is an In-Depth Special Report form the National Center for Atmospheric Research. It contains articles, images, activities, video clips, and interactive graphs to inform learners about meteorology and weather in the colder seasons.

  12. Winter Weather: Outdoor Safety

    MedlinePLUS

    ... About CDC.gov . Natural Disasters and Severe Weather Earthquakes Being Prepared Emergency Supplies Home Hazards Indoor Safety ... What's New A - Z Index Disasters & Severe Weather Earthquakes Extreme Heat Floods Hurricanes Landslides Tornadoes Tsunamis Volcanoes ...

  13. Winter Weather: Frostbite

    MedlinePLUS

    ... About CDC.gov . Natural Disasters and Severe Weather Earthquakes Being Prepared Emergency Supplies Home Hazards Indoor Safety ... What's New A - Z Index Disasters & Severe Weather Earthquakes Extreme Heat Floods Hurricanes Landslides Tornadoes Tsunamis Volcanoes ...

  14. The Aquarius Salinity Product: Intercomparison with SMOS and In-Situ Observations and Importance of the Ocean Surface Roughness Correction

    NASA Astrophysics Data System (ADS)

    Meissner, Thomas; Hilburn, Kyle; Wentz, Frank; Gentemann, Chelle

    2013-04-01

    The Aquarius L-band radiometer/scatterometer system is designed to provide monthly salinity maps at 150 km spatial scale to an accuracy of 0.2 psu. The sensor was launched on June 10, 2011, aboard the Argentine CONAE SAC-D spacecraft. The L-band radiometers and the scatterometer have been taking science data observations since August 25, 2011. This first part of the presentation gives an overview over the major features of the Version 2.1 Aquarius Level 2 salinity retrieval algorithm: 1. Antenna pattern correction: spillover and cross polarization contamination. 2. Correction for the drift of the Aquarius internal calibration system. 3. Correction for intruding celestial radiation, foremost from the galaxy. 4. Correction for effects of the wind roughened ocean surface. We then present a thorough validation study for the salinity product, which consists in a 3-way intercomparison between Aquarius, SMOS and in-situ buoy salinity measurements. The Aquarius - buy comparison shows that that the Aquarius Version 2.1 salinity product is very close to meet the aforementioned mission requirement of 0.2 psu. We demonstrate that in order to meet this accuracy it is crucial to use the L-band scatterometer for correcting effects from the wind roughened ocean surface, which turns out to be the major driver in the salinity retrieval uncertainty budget. A surface roughness correction algorithm that is based solely on auxiliary input of wind fields from numerical weather prediction models (e.g. NCEP, ECMWF) is not sufficient to meet the stringent Aquarius mission requirement, especially at wind speeds above 10 m/s. We show that presence of the Aquarius L-band scatterometer together with the L-band radiometer allows the retrieval of an Aquarius wind speed product whose accuracy matches or exceeds that of other common ocean wind speeds (WindSat, SSMIS). By comparing SMOS and Aquarius salinity fields with the in-situ observations we assess the importance of the roughness correction and the presence of the L-band scatterometer, which is a major difference between the two missions.

  15. How's the Weather Today?

    NSDL National Science Digital Library

    This lesson plan asks students to think about the weather in their area and introduces them to weather and temperature trends in different latitudes of the United States. They will look at the current weather map and record the high temperatures for a few cities. They will conclude by drawing pictures of themselves outdoors in their hometown and in another place that has different weather.

  16. Enviropedia: Introduction to Weather

    NSDL National Science Digital Library

    2007-12-12

    This resource provides an overview of weather, the day-to-day changes in temperature, air pressure, moisture, wind, cloudiness, rainfall and sunshine. Links embedded in the text provide access to descriptions of cloud types and to information on weather hazards such as fog, hurricanes, thunderstorms, and tornadoes. Other topics include meteorology, weather measurements, and weather mapping. Materials are also provided on the water cycle and its elements, such as evaporation, uplift and cooling of air, dew point, condensation, and precipitation.

  17. Stormfax Weather Services

    NSDL National Science Digital Library

    2002-06-10

    This site offers links to a variety of weather information, including national, international and local weather maps and forecasts, satellite and radar imagery, and severe weather warnings. There are also links to diverse resources such as fire maps, glacier inventories, snow depths, storm surges and tropical storms. There are reports and advisories about El Nino and La Nina. The site also has a glossary of weather terms and conversion charts for temperature, wind speed and atmospheric pressure.

  18. Space Weather Now

    NSDL National Science Digital Library

    Space Environment Center

    The Space Weather Now page is intended to give the non-technical user a "plain language" look at space weather. It includes information about relevant events and announcements, data from and about different instruments and satellites watching various aspects of space weather, alerts and advisories, daily themes of products and services, and links appropriate for the various groups of users.

  19. Aviation weather services

    NASA Technical Reports Server (NTRS)

    Sprinkle, C. H.

    1983-01-01

    The primary responsibilities of the National Weather Service (NWS) are to: provide warnings of severe weather and flooding for the protection of life and property; provide public forecasts for land and adjacent ocean areas for planning and operation; and provide weather support for: production of food and fiber; management of water resources; production, distribution and use of energy; and efficient and safe air operations.

  20. Weather Girl Goes Rogue

    NSDL National Science Digital Library

    Deep Rogue Ram

    This humorous video suggests what might happen if a weather forecaster reported the weather in the context of climate change. There is a sharp contrast between the anchor focusing on short-term local concerns and the weather forecaster describing what is happening on a long-term global basis.

  1. Climate and Weather

    NSDL National Science Digital Library

    National Geographic

    This video discusses the differences between climate and weather by defining and presenting examples of each. When presenting examples of weather, the video focuses on severe events and how meteorologists predict and study the weather using measurement, satellites, and radar. The climate focus is primarily on an overview of climate zones.

  2. Weather Fundamentals: Meteorology. [Videotape].

    ERIC Educational Resources Information Center

    1998

    The videos in this educational series, for grades 4-7, help students understand the science behind weather phenomena through dramatic live-action footage, vivid animated graphics, detailed weather maps, and hands-on experiments. This episode (23 minutes) looks at how meteorologists gather and interpret current weather data collected from sources…

  3. METEOROLOGICAL Weather and Forecasting

    E-print Network

    Hawai'i at Manoa, University of

    AMERICAN METEOROLOGICAL SOCIETY Weather and Forecasting EARLY ONLINE RELEASE This is a preliminary School of Ocean and Earth Science and Technology University of Hawaii at Manoa U.S.A. Yun-Ching Lin submitted to Weather and Forecasting July 05, 2010 Corresponding author: Dr. Mong-Ming Lu, Central Weather

  4. Weather Data Gamification 

    E-print Network

    Gargate, Rohit

    2013-07-25

    . With the huge amount of weather data available, we have designed and developed a fantasy weather game. People manage a team of cities with the goal of predicting weather better than other players in their league, and in the process gain an understanding...

  5. Application of surface pressure measurements of O2-band differential absorption radar system in three-dimensional data assimilation on hurricane: Part II - A quasi-observational study

    NASA Astrophysics Data System (ADS)

    Min, Qilong; Gong, Wei; Lin, Bing; Hu, Yongxiang

    2015-01-01

    This is the second part on assessing the impacts of assimilating various distributions of sea-level pressure (SLP) on hurricane simulations, using the Weather and Research Forecast (WRF) three dimensional variational data assimilation system (3DVAR). One key purpose of this series of study is to explore the potential of using remotely sensed sea surface barometric data from O2-band differential absorption radar system currently under development for server weather including hurricane forecasts. In this part II we further validate the conclusions of observational system simulation experiments (OSSEs) in the part I using observed SLP for three hurricanes that passed over the Florida peninsula. Three SLP patterns are tested again, including all available data near the Florida peninsula, and a band of observations either through the center or tangent to the hurricane position. Before the assimilation, a vortex SLP reconstruction technique is employed for the use of observed SLP as discussed in the part I. In agreement with the results from OSSEs, the performance of assimilating SLP is enhanced for the two hurricanes with stronger initial minimum SLP, leading to a significant improvement in the track and position relative to the control where no data are assimilated. On the other hand, however, the improvement in the hurricane intensity is generally limited to the first 24-48 h of integration, while a high resolution nested domain simulation, along with assimilation of SLP in the coarse domain, shows more profound improvement in the intensity. A diagnostic analysis of the potential vorticity suggests that the improved track forecasts are attributed to the combined effects of adjusting the steering wind fields in a consistent manner with having a deeper vortex, and the associated changes in the convective activity.

  6. LDAR observations of a developing thunderstorm correlated with field mill, ground strike location, and weather radar data including the first report of the design and capabilities of a new, time-of-arrival Ground-strike Location System (GSLS)

    NASA Technical Reports Server (NTRS)

    Poehler, H. A.

    1978-01-01

    An experiment designed to observe and measure a thunderstorm prior to, during, and after its development over the Kennedy Space Center was successful. Correlated measurements of airborne field strength, ground-based field strength, LDAR lightning discharge location in the clouds, weather radar percipitation echoes, plus ground strike location with the new KSC Ground Strike Location System (GSLS) were gathered, and reported. This test marks the first operational use of the GSLS System, and this report contains the first report of its design and capabilities.

  7. Modeling Weather Impact on Ground Delay Programs

    NASA Technical Reports Server (NTRS)

    Wang, Yao; Kulkarni, Deepak

    2011-01-01

    Scheduled arriving aircraft demand may exceed airport arrival capacity when there is abnormal weather at an airport. In such situations, Federal Aviation Administration (FAA) institutes ground-delay programs (GDP) to delay flights before they depart from their originating airports. Efficient GDP planning depends on the accuracy of prediction of airport capacity and demand in the presence of uncertainties in weather forecast. This paper presents a study of the impact of dynamic airport surface weather on GDPs. Using the National Traffic Management Log, effect of weather conditions on the characteristics of GDP events at selected busy airports is investigated. Two machine learning methods are used to generate models that map the airport operational conditions and weather information to issued GDP parameters and results of validation tests are described.

  8. Convective Weather Avoidance with Uncertain Weather Forecasts

    NASA Technical Reports Server (NTRS)

    Karahan, Sinan; Windhorst, Robert D.

    2009-01-01

    Convective weather events have a disruptive impact on air traffic both in terminal area and in en-route airspaces. In order to make sure that the national air transportation system is safe and efficient, it is essential to respond to convective weather events effectively. Traffic flow control initiatives in response to convective weather include ground delay, airborne delay, miles-in-trail restrictions as well as tactical and strategic rerouting. The rerouting initiatives can potentially increase traffic density and complexity in regions neighboring the convective weather activity. There is a need to perform rerouting in an intelligent and efficient way such that the disruptive effects of rerouting are minimized. An important area of research is to study the interaction of in-flight rerouting with traffic congestion or complexity and developing methods that quantitatively measure this interaction. Furthermore, it is necessary to find rerouting solutions that account for uncertainties in weather forecasts. These are important steps toward managing complexity during rerouting operations, and the paper is motivated by these research questions. An automated system is developed for rerouting air traffic in order to avoid convective weather regions during the 20- minute - 2-hour time horizon. Such a system is envisioned to work in concert with separation assurance (0 - 20-minute time horizon), and longer term air traffic management (2-hours and beyond) to provide a more comprehensive solution to complexity and safety management. In this study, weather is dynamic and uncertain; it is represented as regions of airspace that pilots are likely to avoid. Algorithms are implemented in an air traffic simulation environment to support the research study. The algorithms used are deterministic but periodically revise reroutes to account for weather forecast updates. In contrast to previous studies, in this study convective weather is represented as regions of airspace that pilots are likely to avoid. The automated system periodically updates forecasts and reassesses rerouting decisions in order to account for changing weather predictions. The main objectives are to reroute flights to avoid convective weather regions and determine the resulting complexity due to rerouting. The eventual goal is to control and reduce complexity while rerouting flights during the 20 minute - 2 hour planning period. A three-hour simulation is conducted using 4800 flights in the national airspace. The study compares several metrics against a baseline scenario using the same traffic and weather but with rerouting disabled. The results show that rerouting can have a negative impact on congestion in some sectors, as expected. The rerouting system provides accurate measurements of the resulting complexity in the congested sectors. Furthermore, although rerouting is performed only in the 20-minute - 2-hour range, it results in a 30% reduction in encounters with nowcast weather polygons (100% being the ideal for perfectly predictable and accurate weather). In the simulations, rerouting was performed for the 20-minute - 2-hour flight time horizon, and for the en-route segment of air traffic. The implementation uses CWAM, a set of polygons that represent probabilities of pilot deviation around weather. The algorithms were implemented in a software-based air traffic simulation system. Initial results of the system's performance and effectiveness were encouraging. Simulation results showed that when flights were rerouted in the 20-minute - 2-hour flight time horizon of air traffic, there were fewer weather encounters in the first 20 minutes than for flights that were not rerouted. Some preliminary results were also obtained that showed that rerouting will also increase complexity. More simulations will be conducted in order to report conclusive results on the effects of rerouting on complexity. Thus, the use of the 20-minute - 2-hour flight time horizon weather avoidance teniques performed in the simulation is expected to provide benefits for short-term weather avoidan

  9. Complete Decoding and Reporting of Aviation Routine Weather Reports (METARs)

    NASA Technical Reports Server (NTRS)

    Lui, Man-Cheung Max

    2014-01-01

    Aviation Routine Weather Report (METAR) provides surface weather information at and around observation stations, including airport terminals. These weather observations are used by pilots for flight planning and by air traffic service providers for managing departure and arrival flights. The METARs are also an important source of weather data for Air Traffic Management (ATM) analysts and researchers at NASA and elsewhere. These researchers use METAR to correlate severe weather events with local or national air traffic actions that restrict air traffic, as one example. A METAR is made up of multiple groups of coded text, each with a specific standard coding format. These groups of coded text are located in two sections of a report: Body and Remarks. The coded text groups in a U.S. METAR are intended to follow the coding standards set by National Oceanic and Atmospheric Administration (NOAA). However, manual data entry and edits made by a human report observer may result in coded text elements that do not follow the standards, especially in the Remarks section. And contrary to the standards, some significant weather observations are noted only in the Remarks section and not in the Body section of the reports. While human readers can infer the intended meaning of non-standard coding of weather conditions, doing so with a computer program is far more challenging. However such programmatic pre-processing is necessary to enable efficient and faster database query when researchers need to perform any significant historical weather analysis. Therefore, to support such analysis, a computer algorithm was developed to identify groups of coded text anywhere in a report and to perform subsequent decoding in software. The algorithm considers common deviations from the standards and data entry mistakes made by observers. The implemented software code was tested to decode 12 million reports and the decoding process was able to completely interpret 99.93 of the reports. This document presents the deviations from the standards and the decoding algorithm. Storing all decoded data in a database allows users to quickly query a large amount of data and to perform data mining on the data. Users can specify complex query criteria not only on date or airport but also on weather condition. This document also describes the design of a database schema for storing the decoded data, and a Data Warehouse web application that allows users to perform reporting and analysis on the decoded data. Finally, this document presents a case study correlating dust storms reported in METARs from the Phoenix International airport with Ground Stops issued by Air Route Traffic Control Centers (ATCSCC). Blowing widespread dust is one of the weather conditions when dust storm occurs. By querying the database, 294 METARs were found to report blowing widespread dust at the Phoenix airport and 41 of them reported such condition only in the Remarks section of the reports. When METAR is a data source for an ATM research, it is important to include weather conditions not only from the Body section but also from the Remarks section of METARs.

  10. An investigation of the observability of ocean-surface parameters using GEOS-3 backscatter data

    NASA Technical Reports Server (NTRS)

    Miller, L. S.; Priester, R. W.

    1978-01-01

    The degree to which ocean surface roughness can be synoptically observed through use of the information extracted from the GEOS-3 backscattered waveform data was evaluated. Algorithms are given for use in estimating the radar sensed waveheight distribution or ocean-surface impulse response. Other factors discussed include comparisons between theoretical and experimental radar cross section values, sea state bias effects, spatial variability of significant waveheight data, and sensor-related considerations.

  11. Toward an estimation of global land surface heat fluxes from multisatellite observations

    Microsoft Academic Search

    Carlos Jiménez; Catherine Prigent; Filipe Aires

    2009-01-01

    The sensitivity of a suite of satellite observations to land surface heat fluxes and the estimation of satellite-derived fluxes using a statistical model are investigated. The satellite data include visible and near-infrared reflectances (Advanced Very High Resolution Radiometer [AVHRR]), thermal infrared surface skin temperature and its diurnal cycle (International Satellite Cloud Climatology Project [ISCCP]), active microwave backscatter (European Remote-sensing Satellite

  12. Space Weathering of Lunar Rocks and Regolith Grains

    NASA Technical Reports Server (NTRS)

    Keller, L. P.

    2013-01-01

    The exposed surfaces of lunar soil grains and lunar rocks become modified and coated over time with a thin rind of material (patina) through complex interactions with the space environment. These interactions encompass many processes including micrometeorite impacts, vapor and melt deposition, and solar wind implantation/sputtering effects that collectively are referred to as "space weathering". Studies of space weathering effects in lunar soils and rocks provide important clues to understanding the origin and evolution of the lunar regolith as well as aiding in the interpretation of global chemical and mineralogical datasets obtained by remote-sensing missions. The interpretation of reflectance spectra obtained by these missions is complicated because the patina coatings obscure the underlying rock mineralogy and compositions. Much of our understanding of these processes and products comes from decades of work on remote-sensing observations of the Moon, the analysis of lunar samples, and laboratory experiments. Space weathering effects collectively result in a reddened continuum slope, lowered albedo, and attenuated absorption features in reflectance spectra of lunar soils as compared to finely comminuted rocks from the same Apollo sites. Space weathering effects are largely surface-correlated, concentrated in the fine size fractions, and occur as amorphous rims on individual soil grains. Rims on lunar soil grains are highly complex and span the range between erosional surfaces modified by solar wind irradiation to depositional surfaces modified by the condensation of sputtered ions and impact-generated vapors. The optical effects of space weathering effects are directly linked to the production of nanophase Fe metal in lunar materials]. The size of distribution of nanophase inclusions in the rims directly affect optical properties given that large Fe(sup o) grains (approx 10 nm and larger) darken the sample (lower albedo) while the tiny Fe(sup o) grains (<5nm) are the primary agent in spectral "reddening". More recent work has focused on the nature and abundance of OH/H2O in the lunar regolith using orbital data and samples analyses. Advances in sample preparation techniques have made possible detailed analyses of patina-coated rock surfaces. Major advances are occurring in quantifying the rates and efficiency of space weathering processes through laboratory experimentation.

  13. Weather affects us

    NSDL National Science Digital Library

    Kimmy

    2009-11-09

    2nd grade weather unit. The students will learn how weather affects us in our daily lives Read and view the video on meteorologists Kid Meteorologist Learn about clouds - watch S'cool Clouds All About Clouds Do scholastic: weather watch and game Weather Read winter storms Interactive Weather Web Pages Read a reason for the season A Reason for the Season Read about precipitation Precipitation Read and view video on flooding Flood: Farming and Erosion Read about air pressure It's a Breeze: How Air Pressure Affects You Read about Hurricanes Hurricanes Do the activities and read ...

  14. Bistatic scattering from a contaminated sea surface observed in C, X, and Ku bands

    NASA Astrophysics Data System (ADS)

    Ghanmi, H.; Khenchaf, A.; Comblet, F.

    2014-10-01

    The aim of the work presented in this paper focuses on the study and analysis of variations of the bistatic electromagnetic signature of the sea surface contaminated by pollutants. Therefore, we will start the numerical analyses of the pollutant effect on the geometrical and physical characteristics of sea surface. Then, we will evaluate the electromagnetic (EM) scattering coefficients of the clean and polluted sea surface observed in bistatic configuration by using the numerical Forward-Backward Method (FBM). The obtained numerical results of the electromagnetic scattering coefficients are studied and given as a function of various parameters: sea state, wind velocity, type of pollutant (sea surface polluted by oil emulsion, and sea surface covered by oil layer), incidence and scattering angles, frequencies bands (C, X and Ku) and radar polarization.

  15. Multichannel conversion of the National Weather Radar Testbed receiver

    Microsoft Academic Search

    G. E. Crain; M. Yeary; Chad Kidder; A. Zahrai; G. Zhang; R. Doviak; R. Palmer; T.-Y. Yu; M. Xue; Y. Zhang; Q. Xu; P. Chilson

    2009-01-01

    The National Weather Radar Testbed (NWRT) system is based on WSR-88D technology enhanced with the significant capability of a phased array antenna. The agile beam capability provides a unique and powerful tool to focus weather radar asset on observation of severe weather phenomena including structures that lead to formation of these storms. The NWRT system has demonstrated the ability to

  16. Climate and Weather Impact Timing of Emergence of Bats

    PubMed Central

    Frick, Winifred F.; Stepanian, Phillip M.; Kelly, Jeffrey F.; Howard, Kenneth W.; Kuster, Charles M.; Kunz, Thomas H.; Chilson, Phillip B.

    2012-01-01

    Interest in forecasting impacts of climate change have heightened attention in recent decades to how animals respond to variation in climate and weather patterns. One difficulty in determining animal response to climate variation is lack of long-term datasets that record animal behaviors over decadal scales. We used radar observations from the national NEXRAD network of Doppler weather radars to measure how group behavior in a colonially-roosting bat species responded to annual variation in climate and daily variation in weather over the past 11 years. Brazilian free-tailed bats (Tadarida brasiliensis) form dense aggregations in cave roosts in Texas. These bats emerge from caves daily to forage at high altitudes, which makes them detectable with Doppler weather radars. Timing of emergence in bats is often viewed as an adaptive trade-off between emerging early and risking predation or increased competition and emerging late which restricts foraging opportunities. We used timing of emergence from five maternity colonies of Brazilian free-tailed bats in south-central Texas during the peak lactation period (15 June–15 July) to determine whether emergence behavior was associated with summer drought conditions and daily temperatures. Bats emerged significantly earlier during years with extreme drought conditions than during moist years. Bats emerged later on days with high surface temperatures in both dry and moist years, but there was no relationship between surface temperatures and timing of emergence in summers with normal moisture levels. We conclude that emergence behavior is a flexible animal response to climate and weather conditions and may be a useful indicator for monitoring animal response to long-term shifts in climate. PMID:22876331

  17. Solar activity and the weather

    NASA Technical Reports Server (NTRS)

    Svalgaard, L.

    1973-01-01

    Some evidence that the weather is influenced by solar activity is reviewed. It appears that the solar magnetic sector structure is related to the circulation of the earth's atmosphere during local winter. About 31/2 days after the passage of a sector boundary the maximum effect is seen: apparently the height of all pressure surfaces increases in high latitudes leading to anticyclogenesis, whereas at midlatitudes the height of the pressure surfaces decreases leading to low pressure systems or to deepening of existing systems. This later effect is clearly seen as an increase in the area of the base of air with absolute vorticity exceeding a given threshold. Since the increase of geomagnetic activity generally is small at a sector boundary, it is speculated that geomagnetic activity as such is not the cause of the response to the sector structure, but that both weather and geomagnetic activity are influenced by the same (unknown) mechanism.

  18. Solar activity and the weather

    NASA Technical Reports Server (NTRS)

    Svalgaard, L.

    1974-01-01

    Some new evidence that the weather is influenced by solar activity is reviewed. It appears that the solar magnetic sector structure is related to the circulation of the earth's atmosphere during local winter. About 3 1/2 days after the passage of a sector boundary the maximum effect is seen; apparently the height of all pressure surfaces increases in high latitudes leading to anticyclogenesis, whereas at midlatitudes the height of the pressure surfaces decreases leading to low pressure systems or to deepening of existing systems. This later effect is clearly seen as an increase in the area of the base of air with absolute vorticity exceeding a given threshold. Since the increase of geomagnetic activity generally is small at a sector boundary it is speculated that geomagnetic activity as such is not the cause of the response to the sector structure but that both weather and geomagnetic activity are influenced by the same (unknown) mechanism.

  19. Ionic migration and weathering in frozen Antarctic soils

    NASA Technical Reports Server (NTRS)

    Ugolini, F. C.; Anderson, D. M.

    1973-01-01

    Soils of continental Antarctica are forming in one of the most severe terrestrial environments. Continuously low temperatures and the scarcity of water in the liquid state result in the development of desert-type soils. In an earlier experiment to determine the degree to which radioactive Na(Cl-36) would migrate from a shallow point source in permafrost, movement was observed. To confirm this result, a similar experiment involving (Na-22)Cl was conducted. Significantly less movement of the Na-22 ion was observed. Ionic movement in the unfrozen interfacial films at mineral surfaces in frozen ground is held to be important in chemical weathering in Antarctic soils.

  20. Differential rates of feldspar weathering in granitic regoliths

    NASA Astrophysics Data System (ADS)

    White, Art F.; Bullen, Thomas D.; Schulz, Marjorie S.; Blum, Alex E.; Huntington, Thomas G.; Peters, Norman E.

    2001-03-01

    Differential rates of plagioclase and K-feldspar weathering commonly observed in bedrock and soil environments are examined in terms of chemical kinetic and solubility controls and hydrologic permeability. For the Panola regolith, in the Georgia Piedmont Province of southeastern United States, petrographic observations, coupled with elemental balances and 87Sr/ 86Sr ratios, indicate that plagioclase is being converted to kaolinite at depths > 6 m in the granitic bedrock. K-feldspar remains pristine in the bedrock but subsequently weathers to kaolinite at the overlying saprolite. In contrast, both plagioclase and K-feldspar remain stable in granitic bedrocks elsewhere in Piedmont Province, such as Davis Run, Virginia, where feldspars weather concurrently in an overlying thick saprolite sequence. Kinetic rate constants, mineral surface areas, and secondary hydraulic conductivities are fitted to feldspar losses with depth in the Panola and Davis Run regoliths using a time-depth computer spreadsheet model. The primary hydraulic conductivities, describing the rates of meteoric water penetration into the pristine granites, are assumed to be equal to the propagation rates of weathering fronts, which, based on cosmogenic isotope dating, are 7 m/10 6 yr for the Panola regolith and 4 m/10 6 yr for the Davis Run regolith. Best fits in the calculations indicate that the kinetic rate constants for plagioclase in both regoliths are factors of two to three times faster than K-feldspar, which is in agreement with experimental findings. However, the range for plagioclase and K-feldspar rates (k r = 1.5 × 10 -17 to 2.8 × 10 -16 mol m -2 s -1) is three to four orders of magnitude lower than for that for experimental feldspar dissolution rates and are among the slowest yet recorded for natural feldspar weathering. Such slow rates are attributed to the relatively old geomorphic ages of the Panola and Davis Run regoliths, implying that mineral surface reactivity decreases significantly with time. Differential feldspar weathering in the low-permeability Panola bedrock environment is more dependent on relative feldspar solubilities than on differences in kinetic reaction rates. Such weathering is very sensitive to primary and secondary hydraulic conductivities (q p and q s), which control both the fluid volumes passing through the regolith and the thermodynamic saturation of the feldspars. Bedrock permeability is primarily intragranular and is created by internal weathering of networks of interconnected plagioclase phenocrysts. Saprolite permeability is principally intergranular and is the result of dissolution of silicate phases during isovolumetric weathering. A secondary to primary hydraulic conductivity ratio of q s/q p = 150 in the Panola bedrock results in kinetically controlled plagioclase dissolution but thermodynamically inhibited K-feldspar reaction. This result is in accord with calculated chemical saturation states for groundwater sampled in the Panola Granite. In contrast, greater secondary conductivities in the Davis Run saprolite, q s/q p = 800, produces both kinetically controlled plagioclase and K-feldspar dissolution. Faster plagioclase reaction, leading to bedrock weathering in the Panola Granite but not at Davis Run, is attributed to a higher anorthite component of the plagioclase and a wetter and warmer climate. In addition, the Panola Granite has an abnormally high content of disseminated calcite, the dissolution of which precedes the plagioclase weathering front, thus creating additional secondary permeability.